1. |
- Barki-Harrington, Liza, et al.
(författare)
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Requirement for direct cross-talk between B1 and B2 kinin receptors for the proliferation of androgen-insensitive prostate cancer PC3 cells
- 2003
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Ingår i: Biochemical Journal. - 0264-6021. ; 371, s. 581-587
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Tidskriftsartikel (refereegranskat)abstract
- Stimulation of endogenous kinin receptors promotes growth of androgen-independent prostate cancer PC3 cells via activation of the mitogenic extracellular-signal-regulated kinase (ERK) pathway. In the present study, we show that kinin-mediated mitogenic signalling and prostate-cell growth involves two subtypes of bradykinin (BK) receptors, B1R and B2R. Specific stimulation of either B1R or B2R by their respective agonists des-Arg(9)-BK and Lys-BK promoted ERK activation and cell growth, whereas selective blockade with specific antagonists des-Arg(9)-[Leu(8)]BK and Hoe 140 respectively obliterated this effect, indicating the presence of both receptor subtypes. However, blockade of B1R also inhibited B2R-mediated ERK activation and cell growth, and, similarly, antagonism of B2R inhibited the B1R-mediated response. Furthermore, both B1R and B2R agonists promoted internalization of B1R, whereas both receptor antagonists blocked this effect. The B1R ligands des-Arg(9)-BK and des-Arg(9)-[Leu(8)]BK had no effect on the binding of BK to B2R, as demonstrated by radioligand competitive binding studies. However, blockade of either B1R or B2R impaired the ability of the reciprocal receptor to produce inositol phosphates, suggesting that the interaction between B1R and B2R is proximal to activation of phospholipase C. These results provide evidence for the existence of B1R-B2R complexes in prostate cancer PC3 cells and demonstrate that antagonism of one receptor interferes with the signalling ability of the other, possibly at the level of receptor-Galpha(q) protein coupling. Selective inhibition of B1R, which is up-regulated in injured and cancerous tissue, may be beneficial for the treatment of advanced prostate cancer.
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2. |
- Bengtson, Sara, et al.
(författare)
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Activation of TAFI on the Surface of Streptococcus pyogenes Evokes Inflammatory Reactions by Modulating the Kallikrein/Kinin System
- 2009
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Ingår i: Journal of Innate Immunity. - : S. Karger AG. - 1662-811X .- 1662-8128. ; 1:1, s. 18-28
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Tidskriftsartikel (refereegranskat)abstract
- Bacteria-controlled regulation of host responses to infection is an important virulence mechanism that has been demonstrated to contribute to disease progression. Here we report that the human pathogen Streptococcus pyogenes employs the procarboxypeptidase TAR (thrombin-activatablefibrinolysis inhibitor) to modulate the kallikrein/kinin system. To this end, bacteria initiate a chain of events starting with the recruitment and activation of TAFI. This is followed by the assembly and induction of the contact system at the streptococcal surface, eventually triggering the release of bradykinin (BK). BK is then carboxyterminally truncated by activated TAFI, which converts the peptide from a kinin B-2 receptor ligand to a kinin B-1 receptor (B1R) agonist. Finally, we show that streptococcal supernatants indirectly amplify the B1R response as they act on peripheral blood mononuclear cells to secrete inflammatory cytokines that in turn stimulate upregulation of the B1R on human fibroblasts. Taken together our findings implicate a critical and novel role for streptococci-bound TAR, as it processes BK to a B1R agonist at the bacterial surface and thereby may redirect inflammation from a transient to a chronic state. Copyright (C) 2008 S. Karger AG, Basel
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3. |
- Bengtson, Sara H, et al.
(författare)
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Kinin receptor expression during Staphylococcus aureus infection.
- 2006
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 108:6, s. 2055-2063
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Tidskriftsartikel (refereegranskat)abstract
- An inappropriate host response to invading bacteria is a critical parameter that often aggravates the outcome of an infection. Staphylococcus aureus is a major human Gram-positive pathogen that causes a wide array of community- and hospital-acquired diseases ranging from superficial skin infections to severe conditions such as staphylococcal toxic shock. Here we find that S aureus induces inflammatory reactions by modulating the expression and response of the B1 and B2 receptors, respectively. This process is initiated by a chain of events, involving staphylococcal-induced cytokine release from monocytes, bacteria-triggered contact activation, and conversion of bradykinin to its metabolite desArg9bradykinin. The data of the present study implicate an important and previously unknown role for kinin receptor regulation in S aureus infections.
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4. |
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5. |
- Broselid, Stefan, et al.
(författare)
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G Protein-coupled Receptor 30 (GPR30) Forms a Plasma Membrane Complex With Membrane-associated Guanylate Kinases (MAGUKs) and AKAP5 That Constitutively Inhibits cAMP Production.
- 2014
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 289:32, s. 22117-22127
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Tidskriftsartikel (refereegranskat)abstract
- GPR30, or G protein-coupled estrogen receptor (GPER), is a GPCR reported to bind 17β-estradiol (E2), couple to the G proteins Gs and Gi/o, and mediate non-genomic estrogenic responses. However, controversies exist regarding the receptor pharmacological profile, effector coupling, and subcellular localization. We addressed the role of the type I PSD-95/Discs-large/ZO-1 homology (PDZ) motif at the receptor C-terminus in receptor trafficking and coupling to cAMP production in HEK293 cells and CHO cells ectopically expressing the receptor, and in MDCK cells expressing native receptor. GPR30 was localized both intracellularly and in the plasma membrane and subject to limited basal endocytosis. E2 and G-1, reported GPR30 agonists, neither stimulated nor inhibited cAMP production through GPR30, nor influenced receptor localization. Instead, GPR30 constitutively inhibited cAMP production stimulated by a heterologous agonist independently of Gi/o. Moreover, siRNA knockdown of native GPR30 increased cAMP production. Deletion of the receptor PDZ motif interfered with inhibition of cAMP production and increased basal receptor endocytosis. GPR30 interacted with membrane-associated guanylate kinases (MAGUKs), including SAP97 and PSD-95, and A-kinase anchoring protein (AKAP) 5 in the plasma membrane in a PDZ-dependent manner. Knockdown of AKAP5 or St-Ht31 treatment, to disrupt AKAP interaction with protein kinase A (PKA) RIIβ regulatory subunit, decreased inhibition of cAMP production, and St-Ht31 increased basal receptor endocytosis. Thus, GPR30 forms a plasma membrane complex with a MAGUK and AKAP5, which constitutively attenuates cAMP production in response to heterologous agonists independently of Gi/o and retains receptors in the plasma membrane.
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6. |
- de Valdivia, Ernesto Gonzalez, et al.
(författare)
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Roles of PDZ-dependent Interactions and N-glycosylation in G Protein-coupled Estrogen Receptor 1 (GPER1)/GPR30-mediated Stimulation of ERK1/2 Activity
- 2018
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Ingår i: FASEB Journal. - : Wiley. - 0892-6638 .- 1530-6860. ; 32:1 Suppl, s. 6-685
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Konferensbidrag (refereegranskat)abstract
- G protein-coupled receptor 30 (GPR30) is a G protein-coupled receptor (GPCR) that is attracting considerable attention in breast cancer and cardiometabolic regulation. Following reports that GPR30 is required for some rapid estrogen responses, e.g. increased cAMP production and ERK1/2 activity, in estrogen receptor (ER)-negative cells, GPR30 was renamed G protein-coupled estrogen receptor 1 (GPER1). However, many questions remain about the identity of the cognate receptor ligand, receptor-effector coupling, and receptor membrane trafficking. To address the mechanism by which human GPR30 activates ERK1/2, we used HEK293 cells with and without ectopic expression of GPR30. Specifically, we investigated the role of the type I PSD-95/Discs-large/ZO-1 homology (PDZ) motif at the receptor C terminus (-SSAV) and three consensus sites for N glycosylation (N-X-S/T) in the receptor N-terminal domain (N25, N32, N44). We found previously that the C-terminal PDZ motif enables the receptor to interact with SAP97 and protein kinase A (PKA)-anchoring protein (AKAP) 5, and this interaction is necessary for retaining the receptor in the plasma membrane and mediating a constitutive decrease in cAMP production that is not inhibited by pertussis toxin, thus independent of Gi/o. Here, we found that the receptor also constitutively increases ERK1/2 activity. Interestingly, this increase was inhibited by PTX as well as by wortmannin, but not by AG1478, indicating it is mediated by Gi/o and phosphoinositide 3-kinase (PI3K) but not epidermal growth factor receptor (EGFR) transactivation. Deleting the receptor PDZ motif or knocking down AKAP5 also inhibited the increase, showing that the PDZ interaction is also necessary for this response. Interestingly, the proposed GPR30 agonist G-1 increased ERK1/2 activity in a GPR30-dependent manner, but this increase was only observed at very low levels of receptor expression below that required for the constitutive increase. Furthermore, deleting the PDZ motif, which completely inhibited the constitutive increase in ERK1/2 activity, did not inhibit the G-1-stimulated increase. Mutating the potential N-glycosylation residues N25 or N32 to I in the GPR30 N-terminal domain did not prevent receptor plasma membrane expression or ERK1/2 activation. On the other hand, mutating N44 to I completely prevented both plasma membrane expression and ERK1/2 activation, and caused receptor degradation. Thus, the PDZ-dependent receptor interaction with SAP97 and AKAP5, and therefore plasma membrane retention, is necessary for constitutive GPR30-mediated stimulation of ERK1/2 activation, whereas G-1-stimulated ERK1/2 activation may remain following constitutive internalization. On the other hand, N-glycosylation of N44 appears to be necessary for maturation of the receptor to the plasma membrane. Support or Funding Information Swedish Research Council and Swedish Cancer Foundation This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
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7. |
- Enquist, Johan, et al.
(författare)
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Kinin-Stimulated B1 Receptor Signaling Depends on Receptor Endocytosis Whereas B2 Receptor Signaling Does Not.
- 2014
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Ingår i: Neurochemical Research. - : Springer Science and Business Media LLC. - 1573-6903 .- 0364-3190. ; 39:6, s. 1037-1047
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Tidskriftsartikel (refereegranskat)abstract
- Kinins are potent pro-inflammatory peptides that act through two G protein-coupled receptor subtypes, B1 (B1R) and B2 (B2R). Kinin-stimulated B2R signaling is often transient, whereas B1R signaling is sustained. This was confirmed by monitoring agonist-stimulated intracellular Ca(2+) mobilization in A10 smooth muscle cells expressing human wild-type B2R and B1R. We further studied the role of receptor membrane trafficking in receptor-mediated phosphoinositide (PI) hydrolysis in model HEK293 cell lines stably expressing the receptors. Treatment of cells with brefeldin A, to inhibit maturation of de novo synthesized receptors, or hypertonic sucrose, to inhibit receptor endocytosis, showed that the basal cell surface receptor turnover was considerably faster for B1R than for B2R. Inhibition of endocytosis, which stabilized B1R on the cell surface, inhibited B1R signaling, whereas B2R signaling was not perturbed. Signaling by a B1R construct in which the entire C-terminal domain was deleted remained sensitive to inhibition of receptor endocytosis, whereas signaling by a B1R construct in which this domain was substituted with the corresponding domain in B2R was not sensitive. B2R and B1R co-expression, which also appeared to stabilize B1R on the cell surface, presumably by receptor hetero-dimerization, also inhibited B1R signaling, whereas B2R signaling was slightly enhanced. Furthermore, the B2R-specific agonist bradykinin (BK) directed both receptors through a common endocytic pathway, whereas the B1R-specific agonist Lys-desArg(9)-BK was unable to do so. These results suggest that B1R-mediated PI hydrolysis depends on a step in receptor endocytosis, whereas B2R-mediated PI hydrolysis does not. We propose that B1R uses at least part of the endocytic machinery to sustain agonist-promoted signaling.
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8. |
- Enquist, Johan, et al.
(författare)
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Kinins promote B2 receptor endocytosis and delay constitutive B1 receptor endocytosis.
- 2007
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Ingår i: Molecular Pharmacology. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 1521-0111 .- 0026-895X. ; 71:2, s. 494-507
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Tidskriftsartikel (refereegranskat)abstract
- Upon sustained insult, kinins are released and many kinin responses, such as inflammatory pain, adapt from a B2 receptor (B2R) type in the acute phase to a B1 receptor (B1R) type in the chronic phase. In this study, we show that kinins modulate receptor endocytosis to rapidly decrease B2R and increase B1R on the cell surface. B2Rs, which require agonist for activity, are stable plasma membrane components without agonist but recruit beta-arrestin 2, internalize in a clathrin-dependent manner, and recycle rapidly upon agonist treatment. In contrast, B1Rs, which are inducible and constitutively active, constitutively internalize without agonist via a clathrin-dependent pathway, do not recruit beta-arrestin 2, bind G protein-coupled receptor sorting protein, and target lysosomes for degradation. Agonist delays B1R endocytosis, thus transiently stabilizing the receptor. Most of the receptor trafficking phenotypes are transplantable from one receptor to the other through exchange of the C-terminal receptor tails, indicating that the tails contain epitopes that are important for the binding of protein partners that participate in the endocytic and postendocytic receptor choices. It is noteworthy that the agonist delay of B1R endocytosis is not transplanted to the B2R via the B1R tail, suggesting that this property of the B1R requires another domain. These events provide a rapid kinin-dependent mechanism for 1) regulating the constitutive B1R activity and 2) shifting the balance of accessible receptors in favor of B1R.
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9. |
- Gonzalez de Valdivia, Ernesto, et al.
(författare)
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Human G protein-coupled Receptor 30 (GPR30) is N -glycosylated and N-terminal Domain Asparagine 44 is Required for Receptor Structure and Activity
- 2019
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Ingår i: Bioscience Reports. - 0144-8463. ; 39:2
-
Tidskriftsartikel (refereegranskat)abstract
- GPR30, or G protein-coupled estrogen receptor (GPER), is a G protein-coupled receptor (GPCR) that is currently attracting considerable attention in breast cancer and cardiometabolic regulation. The receptor was reported to be a novel membrane estrogen receptor mediating rapid non-genomic responses. However, questions remain about both the cognate ligand and the subcellular localization of receptor activity. Here, we used HEK293 cells ectopically expressing N-terminally FLAG-tagged human GPR30 and three unique antibodies (Ab) specifically targeting the receptor N-terminal domain (N-domain) to investigate the role of N -glycosylation in receptor maturation and activity, the latter assayed by constitutive receptor-stimulated ERK1/2 activity. GPR30 expression was complex with receptor species spanning from about 40 kDa to higher molecular masses and localized in the endoplasmatic reticulum (ER), the plasma membrane (PM), and endocytic vesicles. The receptor contains three conserved asparagines, Asn25, Asn32, and Asn44, in consensus N -glycosylation motifs, all in the N-domain, and PNGase F treatment showed that at least one of them is N -glycosylated. Mutating Asn44 to isoleucine inactivated the receptor, yielding a unique receptor species at about 20 kDa that was recognized by Ab only in a denatured state. On the other hand, mutating Asn25 or Asn32 either individually or in combination, or truncating successively N-domain residues 1-42, had no significant effect either on receptor structure, maturation, or activity. Thus, Asn44 in the GPR30 N-domain is required for receptor structure and activity, whereas N-domain residues 1-42, including specifically Asn25 and Asn32, do not play any major structural or functional roles.
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10. |
- Gonzalez, Ernesto, et al.
(författare)
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G protein-coupled Estrogen Receptor 1 (GPER1)/GPR30 Increases ERK1/2 Activity Through PDZ-dependent and -independent Mechanisms
- 2017
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; , s. 9932-9943
-
Tidskriftsartikel (refereegranskat)abstract
- G protein-coupled receptor 30 (GPR30), also called G protein-coupled estrogen receptor 1 (GPER1), is thought to play important roles in breast cancer and cardiometabolic regulation, but many questions remain about ligand activation, effector coupling, and subcellular localization. We showed recently that GPR30 interacts through the C-terminal type I PDZ motif with SAP97 and protein kinase A (PKA)-anchoring protein (AKAP) 5, which anchor the receptor in the plasma membrane and mediate an apparently constitutive decrease in cAMP production independently of Gi/o. Here, we show that GPR30 also constitutively increases ERK1/2 activity. Removing the receptor PDZ motif or knocking down specifically AKAP5 inhibited the increase, showing that this increase also requires the PDZ interaction. However, the increase was inhibited by pertussis toxin (PTX) as well as by wortmannin, but not by AG1478, indicating that Gi/o and phosphoinositide 3-kinase (PI3K) mediate the increase independently of epidermal growth factor receptor (EGFR) transactivation. FK506 and okadaic acid also inhibited the increase, implying that a protein phosphatase is involved. The proposed GPR30 agonist G-1 also increased ERK1/2 activity, but this increase was only observed at a level of receptor expression below that required for the constitutive increase. Furthermore, deleting the PDZ motif did not inhibit the G-1-stimulated increase. Based on these results, we propose that GPR30 increases ERK1/2 activity via two Gi/o-mediated mechanisms; a PDZ-dependent apparently constitutive mechanism, and a PDZ-independent G-1-stimulated mechanism.
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11. |
- Hofmeister, Marlene Vind, et al.
(författare)
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17 beta-Estradiol induces nongenomic effects in renal intercalated cells through G protein-coupled estrogen receptor 1
- 2012
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Ingår i: American Journal of Physiology-Renal Physiology. - : American Physiological Society. - 1522-1466 .- 1931-857X. ; 302:3, s. 358-368
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Tidskriftsartikel (refereegranskat)abstract
- Hofmeister MV, Damkier HH, Christensen BM, Olde B, Leeb-Lundberg LM, Fenton RA, Praetorius HA, Praetorius J. 17 beta-Estradiol induces nongenomic effects in renal intercalated cells through G protein-coupled estrogen receptor 1. Am J Physiol Renal Physiol 302: F358-F368, 2012. First published October 12, 2011; doi: 10.1152/ajprenal.00343.2011.-Steroid hormones such as 17 beta-estradiol (E2) are known to modulate ion transporter expression in the kidney through classic intracellular receptors. Steroid hormones are also known to cause rapid nongenomic responses in a variety of nonrenal tissues. However, little is known about renal short-term effects of steroid hormones. Here, we studied the acute actions of E2 on intracellular Ca2+ signaling in isolated distal convoluted tubules (DCT2), connecting tubules (CNT), and initial cortical collecting ducts (iCCD) by fluo 4 fluorometry. Physiological concentrations of E2 induced transient increases in intracellular Ca2+ concentration ([Ca2+](i)) in a subpopulation of cells. The [Ca2+](i) increases required extracellular Ca2+ and were inhibited by Gd3+. Strikingly, the classic E2 receptor antagonist ICI 182,780 also increased [Ca2+](i), which is inconsistent with the activation of classic E2 receptors. G proteincoupled estrogen receptor 1 (G.PER1 or GPR30) was detected in microdissected DCT2/CNT/iCCD by RT-PCR. Stimulation with the specific GPER1 agonist G-1 induced similar [Ca2+](i) increases as E2, and in tubules from GPER1 knockout mice, E2, G-1, and ICI 182,780 failed to induce [Ca2+](i) elevations. The intercalated cells showed both E2-induced concanamycin-sensitive H+-ATPase activity by BCECF fluorometry and the E2-mediated [Ca2+](i) increment. We propose that E2 via GPER1 evokes [Ca2+](i) transients and increases H+-ATPase activity in intercalated cells in mouse DCT2/CNT/iCCD.
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12. |
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13. |
- Holm, Anders, et al.
(författare)
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The G Protein-Coupled Estrogen Receptor 1 (GPER1/GPR30) Agonist G-1 Regulates Vascular Smooth Muscle Cell Ca Handling.
- 2013
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Ingår i: Journal of Vascular Research. - : S. Karger AG. - 1423-0135 .- 1018-1172. ; 50:5, s. 421-429
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Tidskriftsartikel (refereegranskat)abstract
- The G protein-coupled estrogen receptor GPER1/GPR30 is implicated in blood pressure regulation but the mechanisms are not identified. Here, we hypothesize that GPER1 controls blood pressure by regulating vascular smooth muscle cell Ca(2+) handling. Treatment with the GPER1 agonist G-1 (in the µM concentration range) acutely reduced spontaneous and synchronous Ca(2+) spike activity in A7r5 vascular smooth muscle cells expressing mRNA for GPER1. Furthermore, G-1 (1 µM) attenuated the thromboxane A2 analogue U46619-stimulated Ca(2+) spike activity but had no effect on the U46619-induced increase in the basal level of Ca(2+). The voltage-sensitive L-type Ca(2+) channel blocker nifedipine (100 nM) reduced Ca(2+) spike activity similar to G-1. Pharmacological, but not physiological, concentrations of the estrogen 17β-estradiol reduced Ca(2+) spike activity. The GPER1 antagonist G-15 blocked G-1-induced downregulation of Ca(2+) spike activity, supporting a GPER1-dependent mechanism. G-1 (1 µM) and nifedipine (100 nM) attenuated the 30-mM KCl-evoked rise in intracellular Ca(2+) concentration, suggesting that G-1 blocks inflow of Ca(2+) via voltage-sensitive Ca(2+) channels. In conclusion, we demonstrate that the GPER1 agonist G-1 regulates vascular smooth muscle cell Ca(2+) handling by lowering Ca(2+) spike activity, suggesting a role for this mechanism in GPER1-mediated control of blood pressure. © 2013 S. Karger AG, Basel.
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14. |
- Holm, Anders, et al.
(författare)
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The G protein-coupled oestrogen receptor 1 agonist G-1 disrupts endothelial cell microtubule structure in a receptor-independent manner.
- 2012
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Ingår i: Molecular and Cellular Biochemistry. - : Springer Science and Business Media LLC. - 0300-8177 .- 1573-4919. ; 366:1-2, s. 239-249
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Tidskriftsartikel (refereegranskat)abstract
- The G protein-coupled oestrogen receptor GPER1, also known as GPR30, has been implicated in oestrogen signalling, but the physiological importance of GPER1 is not fully understood. The GPER1 agonist G-1 has become an important tool to assess GPER1-mediated cellular effects. Here, we report that this substance, besides acting via GPER1, affects the microtubule network in endothelial cells. Treatment with G-1 (3 μM) for 24 h reduced DNA synthesis by about 60 % in mouse microvascular endothelial bEnd.3 cells. Treatment with 3 μM G-1 prevented outgrowth of primary endothelial cells from mouse aortic explants embedded in Matrigel. Treatment with G-1 (0.3-3 μM) for 24 h disrupted bEnd.3 cell and HUVEC microtubule structure in a concentration-dependent manner as assessed by laser-scanning confocal immunofluorescence microscopy. G-1-induced (3 μM) disruption of microtubule was observed also after acute (3 and 6 h) treatment and in the presence of the protein synthesis inhibitor cycloheximide. Disruption of microtubules by 3 μM G-1 was observed in aortic smooth muscle cells obtained from both GPER1 knockout and wild-type mice, suggesting that G-1 influences microtubules through a mechanism independent of GPER1. G-1 dose dependently (10-50 μM) stimulated microtubule assembly in vitro. On the other hand, microtubules appeared normal in the presence of 10-50 μM G-1 as determined by electron microscopy. We suggest that G-1-promoted endothelial cell anti-proliferation is due in part to alteration of microtubule organization through a mechanism independent of GPER1. This G-1-promoted mechanism may be used to block unwanted endothelial cell proliferation and angiogenesis such as that observed in, e.g. cancer.
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15. |
- Holm, Anders, et al.
(författare)
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The GPER1 Agonist G-1 Attenuates Endothelial Cell Proliferation by Inhibiting DNA Synthesis and Accumulating Cells in the S and G2 Phases of the Cell Cycle.
- 2011
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Ingår i: Journal of Vascular Research. - : S. Karger AG. - 1423-0135 .- 1018-1172. ; 48:4, s. 327-335
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Tidskriftsartikel (refereegranskat)abstract
- G protein-coupled receptor 30 (GPR30) or G protein-coupled estrogen receptor 1 (GPER1) is expressed in the vasculature, but the importance of vascular GPER1 remains to be clarified. Here we investigate effects of the GPER1 agonist G-1 on endothelial cell proliferation using mouse microvascular endothelial bEnd.3 cells. The bEnd.3 cells express mRNA for GPER1. The bEnd.3 cells expressed both ERα and ERβ immunoreactivities. Treatment with G-1 reduced DNA synthesis and cell number with IC(50) values of about 2 μM. GPER1 siRNA prevented G-1-induced attenuation of DNA synthesis. G-1 accumulated cells in S and G2 phases of the cell cycle, suggesting that G-1 blocks transition between G2 and M. G-1 had no effect on DNA synthesis in COS-7 cells only weakly expressing GPER1 mRNA. 17β-Estradiol had no effect on DNA synthesis in physiological concentrations (nM). The ER blocker ICI182780 reduced DNA synthesis with similar potency as G-1. Treatment with the ERK/MAP kinase inhibitor PD98059 had no effect on G-1-induced attenuation of DNA synthesis. G-1- induced antiproliferation was observed not only in bEnd.3 cells but also in human umbilical vein endothelial cells and HMEC-1 endothelial cells. We conclude that the GPER1 agonist G-1 attenuates endothelial cell proliferation via inhibition of DNA synthesis and by accumulation of cells in S and G2.
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16. |
- Kabir, Mohammad E, et al.
(författare)
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G Protein-Coupled Estrogen Receptor 1 Mediates Acute Estrogen-Induced Cardioprotection via MEK/ERK/GSK-3β Pathway after Ischemia/Reperfusion.
- 2015
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:9
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Tidskriftsartikel (refereegranskat)abstract
- Three types of estrogen receptors (ER) exist in the heart, Esr1, Esr2 and the G protein-coupled estrogen receptor 1, Gper1. However, their relative importance in mediating estrogen protective action is unknown. We found that, in the male mouse ventricle, Gper1 transcripts are three- and seventeen-fold more abundant than Esr1 and Esr2 mRNAs, respectively. Analysis of the three ER knockouts (Esr1-/-, Esr2-/- and Gper1-/-) showed that only the Gper1-/- hearts lost their ability to be protected by 40 nM estrogen as measured by heart function, infarct size and mitochondrial Ca2+ overload, an index of mitochondrial permeability transition pore (mPTP) activity. Analysis of Akt, ERK1/2 and GSK-3β salvage kinases uncovered Akt and ERK1/2 transient activation by estrogen whose phosphorylation increased during the first 5 min of non-ischemic perfusion. All these increase in phosphorylation effects were abrogated in Gper1-/-. Inhibition of MEK1/2/ERK1/2 (1 μM U0126) and PI-3K/Akt (10 μM LY294002) signaling showed that the MEK1/2/ERK1/2 pathway via GSK-3β exclusively was responsible for cardioprotection as an addition of U0126 prevented estrogen-induced GSK-3β increased phosphorylation, resistance to mitochondrial Ca2+-overload, functional recovery and protection against infarction. Further, inhibiting PKC translocation (1 μM chelerythrin-chloride) abolished estrogen-induced cardioprotection. These data indicate that estrogen-Gper1 acute coupling plays a key role in cardioprotection against ischemia/reperfusion injury in male mouse via a cascade involving PKC translocation, ERK1/2/GSK-3β phosphorylation leading to the inhibition of the mPTP opening.
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17. |
- Kahn, Robin, et al.
(författare)
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Microvesicle transfer of kinin B1-receptors is a novel inflammatory mechanism in vasculitis
- 2017
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Ingår i: Kidney International. - : Elsevier BV. - 0085-2538. ; 91:1, s. 96-105
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Tidskriftsartikel (refereegranskat)abstract
- During vasculitis, activation of the kinin system induces inflammation, whereby the kinin B1-receptor is expressed and activated after ligand binding. Additionally, activated blood cells release microvesicles into the circulation. Here we determined whether leukocyte-derived microvesicles bear B1-kinin receptors during vasculitis, and if microvesicles transfer functional B1-receptors to recipient cells, thus promoting inflammation. By flow cytometry, plasma from patients with vasculitis were found to contain high levels of leukocyte-derived microvesicles bearing B1-receptors. Importantly, renal biopsies from two patients with vasculitis showed leukocyte-derived microvesicles bearing B1-receptors docking on glomerular endothelial cells providing in vivo relevance. Microvesicles derived from B1-receptor-transfected human embryonic kidney cells transferred B1-receptors to wild-type human embryonic kidney cells, lacking the receptor, and to glomerular endothelial cells. The transferred B1-receptors induced calcium influx after B1-receptor agonist stimulation: a response abrogated by a specific B1-receptor antagonist. Microvesicles derived from neutrophils also transferred B1-receptors to wild-type human embryonic kidney cells and induced calcium influx after stimulation. Thus, we found a novel mechanism by which microvesicles transfer functional receptors and promote kinin-associated inflammation.
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18. |
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19. |
- Kahn, Robin, et al.
(författare)
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Neutrophil-derived proteinase 3 induces kallikrein-independent release of a novel vasoactive kinin.
- 2009
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Ingår i: Journal of immunology. - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 182:12, s. 7906-7915
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Tidskriftsartikel (refereegranskat)abstract
- The kinin-forming pathway is activated on endothelial cells and neutrophils when high-molecular weight kininogen (HK) is cleaved by plasma kallikrein liberating bradykinin, a potent mediator of inflammation. Kinins are released during inflammatory conditions such as vasculitis, associated with neutrophil influx around blood vessels. Some patients with vasculitis have elevated plasma levels of neutrophil-derived proteinase 3 (PR3) and anti-PR3 Abs. This study investigated if neutrophil-derived PR3 could induce activation of the kinin pathway. PR3 incubated with HK, or a synthetic peptide derived from HK, induced breakdown and release of a novel tridecapeptide termed PR3-kinin, NH(2)-MKRPPGFSPFRSS-COOH, consisting of bradykinin with two additional amino acids on each terminus. The reaction was specific and inhibited by anti-PR3 and alpha(1)-antitrypsin. Recombinant wild-type PR3 incubated with HK induced HK breakdown, whereas mutated PR3, lacking enzymatic activity, did not. PR3-kinin bound to and activated human kinin B(1) receptors, but did not bind to B(2) receptors, expressed by transfected HEK293 cells in vitro. In human plasma PR3-kinin was further processed to the B(2) receptor agonist bradykinin. PR3-kinin exerted a hypotensive effect in vivo through both B(1) and B(2) receptors as demonstrated using wild-type and B(1) overexpressing rats as well as wild-type and B(2) receptor knockout mice. Neutrophil extracts from vasculitis patients and healthy controls contained comparable amounts of PR3 and induced HK proteolysis, an effect that was abolished when PR3 was immunoadsorbed. Neutrophil-derived PR3 can proteolyze HK and liberate PR3-kinin, thereby initiating kallikrein-independent activation of the kinin pathway.
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20. |
- Kang, Dongsoo, et al.
(författare)
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B1 Bradykinin Receptor Homo-oligomers in Receptor Cell Surface Expression and Signaling: Effects of Receptor Fragments.
- 2005
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Ingår i: Molecular Pharmacology. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 1521-0111 .- 0026-895X. ; 67:1, s. 309-318
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Tidskriftsartikel (refereegranskat)abstract
- The human B1 bradykinin receptor is an inducible and constitutively active G protein-coupled receptor that is involved in the inflammatory and pain responses to injury. Here, we investigated the role of B1 receptor homo-oligomerization in cell surface receptor expression. B1 receptors tagged with either the FLAG or hemagglutinin epitope were monitored immunologically and by radio-ligand binding, biotinylation, and phosphoinositide hydrolysis in human embryonic kidney 293 cells. Selective immunoprecipitation, immunoblotting, and immunoelectron microscopy with epitope-specific antibodies together provided evidence for constitutively formed cell surface receptor homo-oligomers. Truncation of the receptor from the N- and C-terminal ends indicated that the epitope for oligomerization seems to be located between Leu26 on top of transmembrane helix 1 and Val71 at the bottom of helix 2. A receptor construct terminating at Asp134 at the bottom of helix 3, B1stop135, was expressed in the cell. It is interesting that this construct behaved as a dominant-negative mutant by competitively preventing formation of intact B1 receptor homo-oligomers, and redistributing B1 receptors from the cell surface to a common intracellular compartment. In contrast, expression of a construct containing the residues downstream of Asp134, B1del(2-134), was inactive in this regard. Together, these results are consistent with a mechanism where constitutive B1 receptor homooligomerization is required for expression of receptors on the cell surface and subsequent constitutive receptor signaling. This may be a novel mechanism by which the cell regulates the presentation of this constitutively highly active receptor at various stages of injury.
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21. |
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22. |
- Kotarsky, Knut, et al.
(författare)
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Lysophosphatidic Acid Binds to and Activates GPR92, a G Protein-Coupled Receptor Highly Expressed in Gastrointestinal Lymphocytes
- 2006
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Ingår i: Journal of Pharmacology and Experimental Therapeutics. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 1521-0103 .- 0022-3565. ; 318:2, s. 619-628
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Tidskriftsartikel (refereegranskat)abstract
- Here, the ligand binding, activation, and tissue distribution of the orphan G protein-coupled receptor (GPCR) GPR92 were studied. GPR92 binds and is activated by compounds based on the lysophosphatidic acid (LPA) backbone. The binding of LPA to GPR92 was of high affinity (K(D) = 6.4 +/- 0.9 nM) and led to an increase in both phosphoinositide hydrolysis and cAMP production. GPR92 is atypical in that it has a low sequence homology with the classic LPA(1-3) receptors (21-22%). Expression of GPR92 is mainly found in heart, placenta, spleen, brain, lung, and gut. Notably, GPR92 is highly expressed in the lymphocyte compartment of the gastrointestinal tract. It is the most abundant GPCR activated by LPA found in the small intestinal intraepithelial CD8+ cytotoxic T cells.
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23. |
- Lamb, ME, et al.
(författare)
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Human B1 and B2 bradykinin receptors and their agonists target caveolae-related lipid rafts to different degrees in HEK293 cells
- 2002
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Ingår i: Biochemistry. - : American Chemical Society (ACS). - 0006-2960 .- 1520-4995. ; 41:48, s. 14340-14347
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Tidskriftsartikel (refereegranskat)abstract
- To address the targeting of G protein-coupled receptors to caveolae-related lipid rafts (CLR), we studied the human B2 (B2R) and B1 (B1R) bradykinin receptor subtypes in HEK293 cells. CLR were enriched on the basis of their unique buoyant density and composition of cholesterol, caveolin-1, and flotillin-1 but not clathrin. CLR contained B2R and B1R as determined by both receptor immunoblotting and the increase in specific activity of receptor agonist binding to cells at both 4 and 37 degreesC when binding was followed by CLR enrichment. B2R was highly enriched in this fraction, whereas B I R was not enriched. Furthermore, acid washing of cells prior to cell disruption minimally affected the CLR-associated B2R agonist binding, whereas it dissociated a major portion of the CLR-associated B I R agonist binding. In addition, when agonist binding at 4 degreesC was followed by an increase in the temperature to 37 degreesC B2R agonist binding in CLR transiently increased, and this increase was dependent on the C-terminal domain. On the other hand, B1R agonist binding remained unchanged and was independent of the C-terminal domain. Our results show that B2R is constitutively targeted to CLR in HEK293 cells and appears to shuttle the agonist through these domains, whereas B1R may be there by default.
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24. |
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25. |
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26. |
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27. |
- Leeb-Lundberg, Fredrik, et al.
(författare)
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International union of pharmacology. XLV. Classification of the kinin receptor family: from molecular mechanisms to pathophysiological consequences.
- 2005
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Ingår i: Pharmacological Reviews. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 0031-6997 .- 1521-0081. ; 57:1, s. 27-77
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Forskningsöversikt (refereegranskat)abstract
- Kinins are proinflammatory peptides that mediate numerous vascular and pain responses to tissue injury. Two pharmacologically distinct kinin receptor subtypes have been identified and characterized for these peptides, which are named B1 and B2 and belong to the rhodopsin family of G protein-coupled receptors. The B2 receptor mediates the action of bradykinin (BK) and lysyl-bradykinin (Lys-BK), the first set of bioactive kinins formed in response to injury from kininogen precursors through the actions of plasma and tissue kallikreins, whereas the B(1) receptor mediates the action of des-Arg9-BK and Lys-des-Arg9-BK, the second set of bioactive kinins formed through the actions of carboxypeptidases on BK and Lys-BK, respectively. The B2 receptor is ubiquitous and constitutively expressed, whereas the B1 receptor is expressed at a very low level in healthy tissues but induced following injury by various proinflammatory cytokines such as interleukin-1beta. Both receptors act through G alpha(q) to stimulate phospholipase C beta followed by phosphoinositide hydrolysis and intracellular free Ca2+ mobilization and through G alpha(i) to inhibit adenylate cyclase and stimulate the mitogen-activated protein kinase pathways. The use of mice lacking each receptor gene and various specific peptidic and nonpeptidic antagonists have implicated both B1 and B2 receptors as potential therapeutic targets in several pathophysiological events related to inflammation such as pain, sepsis, allergic asthma, rhinitis, and edema, as well as diabetes and cancer. This review is a comprehensive presentation of our current understanding of these receptors in terms of molecular and cell biology, physiology, pharmacology, and involvement in human disease and drug development.
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28. |
- Lefler, D, et al.
(författare)
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Jak2 and Ca2+/calmodulin are key intermediates for bradykinin B-2 receptor-mediated activation of Na+/H+ exchange in KNRK and CHO cells
- 2003
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Ingår i: Assay and Drug Development Technologies. - : Mary Ann Liebert Inc. - 1540-658X .- 1557-8127. ; 1:2, s. 281-289
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Tidskriftsartikel (refereegranskat)abstract
- Na+/H+ exchangers are ubiquitous in mammalian cells, carrying out key functions, such as cell volume defense, acid-base homeostasis, and regulation of the cytoskeleton. We used two screening technologies (FLIPR and microphysiometry) to characterize the signal transduction pathway used by the bradykinin beta(2) receptor to activate Na+/H+ exchange in two cell lines, KNRK and CHO. In both cell types, beta(2) receptor activation resulted in rapid increases in the rate of proton extrusion that were sodium-dependent and could be blocked by the Na+/H+ exchange inhibitors EIPA and MIA or by replacing extracellular sodium with TMA. Activation of Na+/H+ exchange by bradykinin was concentration-dependent and could be blocked by the selective beta(2) receptor antagonist HOE140, but not by the beta(1) receptor antagonist des-Arg(10)-HOE140. Inhibitors of Jak2 tyrosine kinase (genistein and AG490) and of CAM (W-7 and calmidazolium) attenuated bradykinin-induced activation of Na+/H+ exchange. Bradykinin induced formation of a complex between CAM and Jak2, supporting a regulatory role for Jak2 and CAM in the activation of Na+/H+ exchange in KNRK and CHO cells. We propose that this pathway (beta(2) receptor --> Jak2 --> CAM --> Na+/H+ exchanger) is a fundamental regulator of Na+/H+ exchange activity.
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29. |
- Lenhart, P.M., et al.
(författare)
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G-protein-coupled receptor 30 interacts with receptor activity-modifying protein 3 and confers sex-dependent cardioprotection
- 2013
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Ingår i: Journal of Molecular Endocrinology. - 1479-6813. ; 51:1, s. 191-202
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Receptor activity-modifying protein 3 (RAMP3) is a single-pass transmembrane protein known to interact with and affect the trafficking of several G-protein-coupled receptors (GPCRs). We sought to determine whether RAMP3 interacts with GPR30, also known as G-protein-coupled estrogen receptor 1. GPR30 is a GPCR that binds estradiol and has important roles in cardiovascular and endocrine physiology. Using bioluminescence resonance energy transfer titration studies, co-immunoprecipitation, and confocal microscopy, we show that GPR30 and RAMP3 interact. Furthermore, the presence of GPR30 leads to increased expression of RAMP3 at the plasma membrane in HEK293 cells. In vivo, there are marked sex differences in the subcellular localization of GPR30 in cardiac cells, and the hearts of Ramp3(-/-) mice also show signs of GPR30 mislocalization. To determine whether this interaction might play a role in cardiovascular disease, we treated Ramp3(+)(/)(+) and Ramp3(-/-) mice on a heart disease-prone genetic background with G-1, a specific agonist for GPR30. Importantly, this in vivo activation of GPR30 resulted in a significant reduction in cardiac hypertrophy and perivascular fibrosis that is both RAMP3 and sex dependent. Our results demonstrate that GPR30-RAMP3 interaction has functional consequences on the localization of these proteins both in vitro and in vivo and that RAMP3 is required for GPR30-mediated cardioprotection.
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30. |
- Maurer, M, et al.
(författare)
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New topics in bradykinin research
- 2011
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Ingår i: Allergy. - : Wiley. - 1398-9995 .- 0105-4538. ; 66:11, s. 1397-1406
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Tidskriftsartikel (refereegranskat)abstract
- Bradykinin has been implicated to contribute to allergic inflammation and the pathogenesis of allergic conditions. It binds to endothelial B(1) and B(2) receptors and exerts potent pharmacological and physiological effects, notably, decreased blood pressure, increased vascular permeability and the promotion of classical symptoms of inflammation such as vasodilation, hyperthermia, oedema and pain. Towards potential clinical benefit, bradykinin has also been shown to exert potent antithrombogenic, antiproliferative and antifibrogenic effects. The development of pharmacologically active substances, such as bradykinin receptor blockers, opens up new therapeutic options that require further research into bradykinin. This review presents current understanding surrounding the role of bradykinin in nonallergic angioedema and other conditions seen by allergists and emergency physicians, and its potential role as a therapeutic target.
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31. |
- Mossberg, Maria, et al.
(författare)
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Cl-Inhibitor Decreases the Release of Vasculitis-Like Chemotactic Endothelial Microvesicles
- 2017
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Ingår i: Journal of the American Society of Nephrology. - : AMER SOC NEPHROLOGY. - 1046-6673 .- 1533-3450. ; 28:8, s. 2472-2481
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Tidskriftsartikel (refereegranskat)abstract
- The kinin system is activated during vasculitis and may contribute to chronic inflammation. C1-inhibitor is the main inhibitor of the kinin system. In this study, we investigated the presence of the kinin B1 receptor on endothelial microvesicles and its contribution to the inflammatory process. Compared with controls (n=15), patients with acute vasculitis (n=12) had markedly higher levels of circulating endothelial micro vesicles, identified by flow cytometry analysis, and significantly more microvesicles that were positive for the kinin B1 receptor (Pamp;lt;0.001). Compared with microvesicles from wild-type cells, B1 receptor-positive microvesicles derived from transfected human embryonic kidney cells induced a significant neutrophil chemotactic effect, and a B1 receptor antagonist blocked this effect. Likewise, patient plasma induced neutrophil chemotaxis, an effect decreased by reduction of microvesicle levels and by blocking the B1 receptor. We used a perfusion system to study the effect of patient plasma (n=6) and control plasma (n=6) on the release of microvesicles from glomerular endothelial cells. Patient samples induced the release of significantly more B1 receptor-positive endothelial microvesicles than control samples, an effect abrogated by reduction of the microvesicles in the perfused samples. Perfusion of C1-inhibitor depleted plasma over glomerular endothelial cells promoted excessive release of B1 receptor-positive endothelial microvesicles compared with normal plasma, an effect significantly decreased by addition of C1-inhibitor or B1 receptor-antagonist. Thus, B1 receptor-positive endothelial microvesicles may contribute to chronic inflammation by inducing neutrophil chemotaxis, and the reduction of these microvesicles by C1-inhibitor should be explored as a potential treatment for neutrophil-induced inflammation.
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32. |
- Mårtensson, Ulrika, et al.
(författare)
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Deletion of the G protein-coupled receptor 30 impairs glucose tolerance, reduces bone growth, increases blood pressure, and eliminates estradiol-stimulated insulin release in female mice.
- 2009
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Ingår i: Endocrinology. - : The Endocrine Society. - 1945-7170 .- 0013-7227. ; 150:2, s. 687-98
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Tidskriftsartikel (refereegranskat)abstract
- In vitro studies suggest that the G protein-coupled receptor (GPR) 30 is a functional estrogen receptor. However, the physiological role of GPR30 in vivo is unknown, and it remains to be determined whether GPR30 is an estrogen receptor also in vivo. To this end, we studied the effects of disrupting the GPR30 gene in female and male mice. Female GPR30((-/-)) mice had hyperglycemia and impaired glucose tolerance, reduced body growth, increased blood pressure, and reduced serum IGF-I levels. The reduced growth correlated with a proportional decrease in skeletal development. The elevated blood pressure was associated with an increased vascular resistance manifested as an increased media to lumen ratio of the resistance arteries. The hyperglycemia and impaired glucose tolerance in vivo were associated with decreased insulin expression and release in vivo and in vitro in isolated pancreatic islets. GPR30 is expressed in islets, and GPR30 deletion abolished estradiol-stimulated insulin release both in vivo in ovariectomized adult mice and in vitro in isolated islets. Our findings show that GPR30 is important for several metabolic functions in female mice, including estradiol-stimulated insulin release.
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33. |
- Narbe, Ulrik, et al.
(författare)
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AIB1 is a new putative prognostic biomarker in the luminal A and B-like (HER2-negative) classification of invasive lobular carcinoma
- 2017
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Ingår i: ; , s. 1-07
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Konferensbidrag (refereegranskat)abstract
- Body: Background: Estrogen receptor (ER) positive HER2-negative breast cancer comprises 75–80% of all breast cancer. Thisfraction is even higher (>90%) in invasive lobular carcinoma (ILC). According to the St Gallen surrogate definitions of the intrinsicsubtypes, Ki67 and progesterone receptor (PgR) are used to classify these tumors as luminal A- and luminal B-like(HER2-negative). These guidelines are based on information derived from patient materials with mixed histological types, wherethe vast majority of the patients have invasive ductal carcinoma. The `luminal-like classification´ together with histological grade,tumor size and lymph node status is widely used in the clinic for prognostication. The aim of the present study was to investigateif the same markers are applicable for ILC, and furthermore, if additional biomarkers involved in the endocrine signaling system,e.g. Amplified in breast cancer 1 (AIB1) and the putative G protein-coupled estrogen receptor (GPER), might providecomplementary prognostic information.Patients: Two hundred and thirty-three (N = 233) well-characterized patients with primary ILC, diagnosed between 1980 and1991 were included. Forty-two percent of the patients received adjuvant endocrine treatment and 2 % received adjuvantchemotherapy. All biomarkers were analyzed immunohistochemically on tissue microarray, whereas histological grade wasevaluated on whole sections according to Elston and Ellis (NHG). The primary endpoint was breast cancer mortality (BCM).Results: In univariable analyses with 10-year follow-up, Ki67 (high vs. low), NHG (3 vs. 1+2) and AIB1 (high vs. low) weresignificantly associated to BCM (Hazard Ratio: 4.7, 95% CI: 2.1–10.4, p 95% CI: 1.4–7.2, p = 0.005 respectively), whereas PgR (respectively). Essentially the same effect was seen after multivariable adjustment for lymph node status (+ vs. -), tumor size (>20mm vs. according to St Gallen surrogate definitions did not show significant prognostic differences between the two groups (p = 0.12).Patients with AIB1) had a 10-year BCM of 4.2% (95% CI: 1.4–12%). This group constituted 34% of the patients included in the present study.Conclusions: In contrast to other previous studies, where breast cancers of mixed histological types were included, PgR was notsignificantly associated to prognosis in the ER-positive HER2-negative subgroup in the present study, consisting only of ILC. Theprognostic role of PgR and the clinical usefulness of the luminal A and B-like (HER2-negative) classification (using only Ki67 andPgR) in ILC is still to be further investigated. The prognostic importance of Ki67 and NHG in this subgroup was, however,confirmed also in ILC, and AIB1 might be a new putative prognostic factor. By combining Ki67, NHG, and AIB1, together withlymph node status and tumor size, a group of patients with an excellent prognosis could be identified.
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34. |
- Narbe, Ulrik, et al.
(författare)
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The estrogen receptor coactivator AIB1 is a new putative prognostic biomarker in ER-positive/HER2-negative invasive lobular carcinoma of the breast
- 2019
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Ingår i: Breast Cancer Research and Treatment. - : Springer Science and Business Media LLC. - 0167-6806 .- 1573-7217. ; 175:2, s. 305-316
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: According to the 2017 St Gallen surrogate definitions of the intrinsic subtypes, Ki67, progesterone receptor (PR) and Nottingham histological grade (NHG) are used for prognostic classification of estrogen receptor (ER) positive/HER2-negative breast cancer into luminal A- or luminal B-like. The aim of the present study was to investigate if additional biomarkers, related to endocrine signaling pathways, e.g., amplified in breast cancer 1 (AIB1), androgen receptor (AR), and G protein-coupled estrogen receptor (GPER), can provide complementary prognostic information in a subset of ER-positive/HER-negative invasive lobular carcinoma (ILC). Methods: Biomarkers from 224 patients were analyzed immunohistochemically on tissue microarray. The primary endpoint was breast cancer mortality (BCM), analyzed with 10- and 25-year follow-up (FU). In addition, the prognostic value of gene expression data for these biomarkers was analyzed in three publicly available ILC datasets. Results: AIB1 (high vs. low) was associated to BCM in multivariable analysis (adjusted for age, tumor size, nodal status, NHG, Ki67, luminal-like classification, and adjuvant systemic therapy) with 10-year FU (HR 6.8, 95% CI 2.3–20, P = 0.001) and 25-year FU (HR 3.0, 95% CI 1.1–7.8, P = 0.03). The evidence of a prognostic effect of AIB1 could be confirmed by linking gene expression data to outcome in independent publicly available ILC datasets. AR and GPER were neither associated to BCM with 10-year nor with 25-year FU (P > 0.33). Furthermore, Ki67 and NHG were prognostic for BCM at both 10-year and 25-year FU, whereas PR was not. Conclusions: AIB1 is a new putative prognostic biomarker in ER-positive/HER2-negative ILC.
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35. |
- Nilsson, Bengt-Olof, et al.
(författare)
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G protein-coupled oestrogen receptor 1 (GPER1)/GPR30: a new player in cardiovascular and metabolic oestrogenic signalling
- 2011
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Ingår i: British Journal of Pharmacology. - : Wiley. - 1476-5381 .- 0007-1188. ; 163:6, s. 1131-1139
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Forskningsöversikt (refereegranskat)abstract
- Oestrogens are important sex hormones central to health and disease in both genders that have protective effects on the cardiovascular and metabolic systems. These hormones act in complex ways via both genomic and non-genomic mechanisms. The genomic mechanisms are relatively well characterized, whereas the non-genomic ones are only beginning to be explored. Two oestrogen receptors (ER), ER alpha and ER beta, have been described that act as nuclear transcription factors but can also associate with the plasma membrane and influence cytosolic signalling. ERa has been shown to mediate both anti-atherogenic effects and pro-survival effects in pancreatic beta-cells. In recent years, a third membrane-bound ER has emerged, G protein-coupled receptor 30 or G protein-coupled oestrogen receptor 1 (GPER1), which mediates oestrogenic responses in cardiovascular and metabolic regulation. Both GPER1 knock-out models and pharmacological agents are now available to study GPER1 function. These tools have revealed that GPER1 activation may have several beneficial effects in the cardiovascular system including vasorelaxation, inhibition of smooth muscle cell proliferation, and protection of the myocardium against ischaemia/reperfusion injury, and in the metabolic system including stimulation of insulin release and protection against pancreatic beta-cell apoptosis. Thus, GPER1 is emerging as a candidate therapeutic target in both cardiovascular and metabolic disease.
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36. |
- Olde, Björn, et al.
(författare)
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GPR30/GPER1: searching for a role in estrogen physiology.
- 2009
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Ingår i: Trends in Endocrinology and Metabolism. - : Elsevier BV. - 1879-3061 .- 1043-2760. ; 20, s. 409-416
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Tidskriftsartikel (refereegranskat)abstract
- Estrogens are sex hormones that are central to health and disease in both genders. These hormones have long been recognized to act in complex ways, both through relatively slow genomic mechanisms and via fast non-genomic mechanisms. Several recent in vitro studies suggest that GPR30, or G protein-coupled estrogen receptor 1 (GPER1), is a functional membrane estrogen receptor involved in non-genomic estrogen signaling. However, this function is not universally accepted. Studies concerning the role of GPER1 in vivo are now beginning to appear but with divergent results. In this review we discuss current knowledge on the physiological role of GPER1 in the nervous system as well as in reproduction, metabolism, bone, and in the cardiovascular and immune systems.
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37. |
- Phagoo, SB, et al.
(författare)
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Infection-induced kinin B-1 receptors in human pulmonary fibroblasts: Role of intact pathogens and p38 mitogen-activated protein kinase-dependent signaling
- 2005
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Ingår i: Journal of Pharmacology and Experimental Therapeutics. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 1521-0103 .- 0022-3565. ; 313:3, s. 1231-1238
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Tidskriftsartikel (refereegranskat)abstract
- Kinin B-1 receptors (B1R) are involved in many pathophysiological processes, and its expression is up-regulated in inflammatory pulmonary disease. Although bacteria can generate kinin peptides, the molecular signaling mechanisms regulating B1R during infection by intact pathogens is unknown. The serious opportunistic clinical isolate Burkholderia cenocepacia (B. cen.) belongs to the important B. cepacia complex (Bcc) of gramnegative pathogens that rapidly causes fatal pulmonary disease in hospitalized and immunocompromised patients and those with cystic fibrosis. We demonstrate here that B. cen. infection induced a rapid increase in B1R mRNA (1 h) proceeded by an increase in B1R protein expression (2 h), without affecting B-2 receptor expression in human pulmonary fibroblasts. The B1R response was dose-dependent and maximal by 6 to 8 h (3- to 4- fold increase), however, brief B. cen. infection could sustain B1R up-regulation. In contrast, nonclinical Bcc phytopathogens were much less B1R inducive. The protein synthesis inhibitor cycloheximide and transcriptional inhibitor actinomycin D abrogated the B-1 response to B. cen. indicating de novo B1R synthesis. B. cen. activated p38 mitogen-activated protein kinase ( MAPK), and blocking p38 MAPK with the specific inhibitor 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl) 1H-imidazole (SB 203580) dramatically reduced B. cen.-induced B1R. Furthermore, B. cen. regulation of B1R was diminished by the anti-inflammatory glucocorticoid dexamethasone. In conclusion, this study is the first demonstration that infection with intact pulmonary pathogens like B. cen. positively modulates the selective expression of B1R. Thus, providing evidence that B1R regulation may be an important and novel mechanism in the inflammatory cascade in response to chronic pulmonary infection and disease.
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38. |
- Qadri, Fatimunnisa, et al.
(författare)
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Acute hypothalamo-pituitary-adrenal axis response to LPS-induced endotoxemia: expression pattern of kinin type B1 and B2 receptors
- 2016
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Ingår i: Biological Chemistry. - : Walter de Gruyter GmbH. - 1437-4315 .- 1431-6730. ; 397:2, s. 97-109
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Tidskriftsartikel (refereegranskat)abstract
- Bradykinin (BK) and des-Arg(9)-BK are pro-inflammatory mediators acting via B2 (B2R) and B1 (B1R) receptors, respectively. We investigated the role of B2R and B1R in lipopolysaccharide (LPS)-induced hypothalamopituitary-adrenal (HPA) axis activation in SD rats. LPS given intraperitoneally (ip) up-regulated B1R mRNA in the hypothalamus, both B1R and B2R were up-regulated in pituitary and adrenal glands. Receptor localization was performed using immunofluorescence staining. B1R was localized in the endothelial cells, nucleus supraopticus (SON), adenohypophysis and adrenal cortex. B2R was localized nucleus paraventricularis (PVN) and SON, pituitary and adrenal medulla. Blockade of B1R prior to LPS further increased ACTH release and blockade of B1R 1 h after LPS decreased its release. In addition, we evaluated if blockade of central kinin receptors influence the LPS-induced stimulation of hypothalamic neurons. Blockade of both B1R and B2R reduced the LPS-induced c-Fos immunoreactivity in the hypothalamus. Our data demonstrate that a single injection of LPS induced a differential expression pattern of kinin B1R and B2R in the HPA axis. The tissue specific cellular localization of these receptors indicates that they may play a crucial role in the maintenance of body homeostasis during endotoxemia.
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39. |
- Sandén, Caroline, et al.
(författare)
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G Protein-Coupled Estrogen Receptor 1 (GPER1)/GPR30 Localizes in the Plasma Membrane and Trafficks Intracellularly on Cytokeratin Intermediate Filaments.
- 2011
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Ingår i: Molecular Pharmacology. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 1521-0111 .- 0026-895X. ; 79:3, s. 400-410
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Tidskriftsartikel (refereegranskat)abstract
- GPR30, or G protein-coupled estrogen receptor 1 (GPER1), was recently introduced as a membrane estrogen receptor and a candidate cancer biomarker and therapeutic target. However, several questions surround the subcellular localization and signaling of this receptor. In native cells, including mouse myoblast C(2)C(12) cells, Madine-Darby canine kidney (MDCK) epithelial cells, and human ductal breast epithelial tumor T47-D cells, G-1, a GPER1 agonist, and 17β-estradiol (E2) stimulated GPER1-dependent cAMP production, a defined plasma membrane (PM) event, and recruitment of β-arrestin2 to the PM. Staining of fixed and live cells showed that GPER1 was localized both in the PM and on intracellular structures. One such intracellular structure was identified as cytokeratin (CK) intermediate filaments, including those composed of CK7 and CK8, but apparently not endoplasmatic reticulum (ER), Golgi, or microtubules. Reciprocal co-immunoprecipitation of GPER1 and CKs confirmed an association of these proteins. Live staining also showed that the PM receptors constitutively internalize apparently to reach CK filaments. Receptor localization was supported using FLAG- and HA-tagged GPER1. We conclude that GPER1-mediated stimulation of cAMP production and β-arrestin2 recruitment occur in the PM. Furthermore, the PM receptors constitutively internalize and localize intracellularly on CK. This is the first observation that a G protein-coupled receptor (GPCR) is capable of associating with intermediate filaments, which may be important for GPER1 regulation in epithelial cells and the relationship of this receptor to cancer.
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40. |
- Sandén, Caroline, et al.
(författare)
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Kinin B1 receptor homo-oligomerization is required for receptor trafficking to the cell surface.
- 2013
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Ingår i: International Immunopharmacology. - : Elsevier BV. - 1878-1705 .- 1567-5769. ; 15:1, s. 121-128
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Tidskriftsartikel (refereegranskat)abstract
- The kinin B1 receptor (B1R) is a G protein-coupled receptor with pro-inflammatory activity that is latent in healthy tissues but induced by tissue insult. Here, we investigated if B1R homo-oligomerization is a possible mechanism regulating the presentation of this receptor at the level of maturation and trafficking to the cell surface. To this end, we used HEK293 cells stably expressing N-terminal FLAG and HA epitope-tagged wild-type human B1R and an N-terminal receptor fragment, B1stop135, which terminates at the C-terminal end of the third transmembrane domain and has previously been shown to oligomerize with B1R. Receptors were monitored by immunoblotting and immunoprecipitation, receptor function by agonist binding and agonist-promoted phosphoinositide hydrolysis, and receptor trafficking by confocal immunofluorescence microscopy. When expressed alone, B1R is core N-glycosylated and forms oligomers localized intracellularly and on the cell surface. B1stop135 also exists as core N-glycosylated oligomers but is localized exclusively intracellularly. When co-expressed, B1stop135 prevents specifically B1R homo-oligomerization by forming nonfunctional B1R-B1stop135 hetero-oligomers, retains B1R intracellularly at least in part in the endoplasmatic reticulum (ER), increases calnexin binding to the receptor, and increases receptor degradation. We conclude that B1R homo-oligomerization is necessary for B1R maturation and trafficking to the cell surface. Modulating this mechanism may be a novel therapeutic avenue in inflammatory disease.
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41. |
- Sandén, Caroline, et al.
(författare)
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Kinin B2 Receptor-Mediated Bradykinin Internalization and Metalloendopeptidase EP24.15-Dependent Intracellular Bradykinin Degradation.
- 2008
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Ingår i: Journal of Pharmacology and Experimental Therapeutics. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 1521-0103 .- 0022-3565. ; 326:1, s. 24-32
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Tidskriftsartikel (refereegranskat)abstract
- Kinins are potent proinflammatory peptides that are produced extracellularly and rapidly degraded by extracellular peptidases and by intracellular peptidases accessed by kinins via receptor-mediated endocytosis. Here, we developed model cell systems expressing the kinin B2 receptor (B2R) and the metalloendopeptidase thimet oligopeptidase (EC 3.4.24.15; EP24.15) either individually or together to address 1) the cellular and functional relationship between these proteins and 2) the participation of EP24.15 in the metabolism of bradykinin (BK) following BK internalization via B2R. B2R was localized almost exclusively in the plasma membrane, whereas EP24.15 was localized both intracellularly and on the cell surface, and secreted in the media. Intracellular EP24.15 was present throughout the cell, both cytosolic and particulate, with less nuclear localization and no co-localization with either the endoplasmatic reticulum marker calnexin or Golgi marker GM130. No direct co-localization of B2R and EP24.15 was observed using immunofluorescence microscopy. However, the two proteins co-immunoprecipitated specifically, and EP24.15 attenuated maximal B2R responsiveness without influencing the potency of BK to stimulate phosphoinositide hydrolysis and intracellular Ca(2+) mobilization. Cell surface-bound BK remained intact in cells overexpressing EP24.15 but was degraded intracellularly in an EP24.15-dependent manner upon B2R-mediated endocytosis. These results show that EP24.15 acts to negatively regulate B2R responsiveness and by serving as an intracellular peptidase in the degradation of BK specifically internalized via this receptor.
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42. |
- Sigurdsson, Valgardur, et al.
(författare)
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Bile Acids Protect Expanding Hematopoietic Stem Cells from Unfolded Protein Stress in Fetal Liver.
- 2016
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Ingår i: Cell Stem Cell. - : Elsevier BV. - 1934-5909. ; 18:4, s. 32-522
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Tidskriftsartikel (refereegranskat)abstract
- During development, hematopoietic stem cells (HSCs) undergo a rapid expansion in the fetal liver (FL) before settling in the adult bone marrow. We recently reported that proliferating adult HSCs are vulnerable to ER stress caused by accumulation of mis-folded proteins. Here, we find that FL-HSCs, despite an increased protein synthesis rate and a requirement for protein folding, do not upregulate ER chaperones. Instead, bile acids (BAs), secreted from maternal and fetal liver, coordinate to serve as chemical chaperones. Taurocholic acid, the major BA in FL, supports growth of HSCs in vitro by inhibiting protein aggregation. In vivo, reducing BA levels leads to ER stress elevation and accumulation of aggregated proteins and significantly decreases the number of FL-HSCs. Taken together, these findings reveal that BA alleviation of ER stress is a mechanism required for HSC expansion during fetal hematopoiesis.
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43. |
- Sjöström, Martin, et al.
(författare)
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Lack of G protein-coupled estrogen receptor (GPER) in the plasma membrane is associated with excellent long-term prognosis in breast cancer
- 2014
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Ingår i: Breast Cancer Research and Treatment. - : Springer Verlag (Germany). - 0167-6806 .- 1573-7217. ; 145:1, s. 61-71
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Tidskriftsartikel (refereegranskat)abstract
- G protein-coupled estrogen receptor (GPER), or GPR30, is a membrane receptor reported to mediate non-genomic estrogen responses. Tamoxifen is a partial agonist at GPER in vitro. Here, we investigated if GPER expression is prognostic in primary breast cancer, if the receptor is treatment-predictive for adjuvant tamoxifen, and if receptor subcellular localization has any impact on the prognostic value. Total and plasma membrane (PM) GPER expression was analyzed by immunohistochemistry in breast tumors from 742 postmenopausal lymph node-negative patients subsequently randomized for tamoxifen treatment for 2-5 years versus no systemic treatment, regardless of estrogen receptor (ER) status, and with a median follow-up of 17 years for patients free of event. PM GPER expression was a strong independent prognostic factor for poor prognosis in breast cancer without treatment-predictive information for tamoxifen. In the tamoxifen-treated ER-positive and progesterone receptor (PgR)-positive patient subgroup, the absence of PM GPER (53 % of all ER-positive tumors) predicted 91 % 20-year distant disease-free survival, compared to 73 % in the presence of GPER (p = 0.001). Total GPER expression showed positive correlations with ER and PgR and negative correlation with histological grade, but the correlations were biphasic. On the other hand, PM GPER expression showed strong negative correlations with ER and PgR, and strong positive correlation with HER2 overexpression and high histological grade. GPER overexpression and PM localization are critical events in breast cancer progression, and lack of GPER in the PM is associated with excellent long-term prognosis in ER-positive and PgR-positive tamoxifen-treated primary breast cancer.
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44. |
- Taub, JS, et al.
(författare)
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Bradykinin receptor subtype 1 expression and function in prostate cancer
- 2003
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Ingår i: Cancer Research. - 1538-7445. ; 63:9, s. 2037-2041
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Tidskriftsartikel (refereegranskat)abstract
- Kinins exert multiple pathophysiological functions, including vascular permeability and mitogenesis, by activating their cognate receptors, bradykinin subtype 1 receptor (B1R) and bradykinin subtype 2 receptor (B2R), which belong to the superfamily of G protein-coupled receptors. Tissue-specific expression pattern or contribution of the individual kinin receptors to pathological prostate cell growth is not known. We report here the differential expression of B1R and B2R in human benign and malignant prostate specimens. Whereas B2R is ubiquitously expressed, the B1R is detected only in prostatic intraepithelial neoplasia and malignant lesions and not in benign prostate tissues. Using androgen-insensitive prostate cancer PC3 cells, we show that specific stimulation of endogenous B1R promotes cell growth, migration, and invasion. These findings identify B1R as an early marker for pathological growth of the prostate and suggest its potential utility as a drug target effective for the treatment of prostate cancer.
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45. |
- Tutzauer, Julia, et al.
(författare)
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Breast cancer hypoxia in relation to prognosis and benefit from radiotherapy after breast-conserving surgery in a large, randomised trial with long-term follow-up
- 2022
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Ingår i: British Journal of Cancer. - : Springer Science and Business Media LLC. - 1532-1827 .- 0007-0920. ; 126:8, s. 1145-1156
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Breast-conserving surgery followed by radiotherapy is part of standard treatment for early-stage breast cancer. Hypoxia is common in cancer and may affect the benefit of radiotherapy. Cells adapt to hypoxic stress largely via the transcriptional activity of hypoxia-inducible factor (HIF)-1α. Here, we aim to determine whether tumour HIF-1α-positivity and hypoxic gene-expression signatures associated with the benefit of radiotherapy, and outcome.METHODS: Tumour HIF-1α-status and expression of hypoxic gene signatures were retrospectively analysed in a clinical trial where 1178 women with primary T1-2N0M0 breast cancer were randomised to receive postoperative radiotherapy or not and followed 15 years for recurrence and 20 years for breast cancer death.RESULTS: The benefit from radiotherapy was similar in patients with HIF-1α-positive and -negative primary tumours. Both ipsilateral and any breast cancer recurrence were more frequent in women with HIF-1α-positive primary tumours (hazard ratio, HR0-5 yrs1.9 [1.3-2.9], p = 0.003 and HR0-5 yrs = 2.0 [1.5-2.8], p < 0.0001). Tumour HIF-1α-positivity is also associated with increased breast cancer death (HR0-10 years 1.9 [1.2-2.9], p = 0.004). Ten of the 11 investigated hypoxic gene signatures correlated positively to HIF-1α-positivity, and 5 to increased rate/risk of recurrence.CONCLUSIONS: The benefit of postoperative radiotherapy persisted in patients with hypoxic primary tumours. Patients with hypoxic primary breast tumours had an increased risk of recurrence and breast cancer death.
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46. |
- Tutzauer, Julia, et al.
(författare)
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G protein-coupled estrogen receptor (GPER)/GPR30 forms a complex with the β1-adrenergic receptor, a membrane-associated guanylate kinase (MAGUK) scaffold protein, and protein kinase A anchoring protein (AKAP) 5 in MCF7 breast cancer cells
- 2024
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Ingår i: Archives of Biochemistry and Biophysics. - 0003-9861. ; 752
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Tidskriftsartikel (refereegranskat)abstract
- G protein-coupled receptor 30 (GPR30), also named G protein-coupled estrogen receptor (GPER), and the β1-adrenergic receptor (β1AR) are G protein-coupled receptors (GPCR) that are implicated in breast cancer progression. Both receptors contain PSD-95/Discs-large/ZO-1 homology (PDZ) motifs in their C-terminal tails through which they interact in the plasma membrane with membrane-associated guanylate kinase (MAGUK) scaffold proteins, and in turn protein kinase A anchoring protein (AKAP) 5. GPR30 constitutively and PDZ-dependently inhibits β1AR-mediated cAMP production. We hypothesized that this inhibition is a consequence of a plasma membrane complex of these receptors. Using co-immunoprecipitation, confocal immunofluorescence microscopy, and bioluminescence resonance energy transfer (BRET), we show that GPR30 and β1AR reside in close proximity in a plasma membrane complex when transiently expressed in HEK293. Deleting the GPR30 C-terminal PDZ motif (-SSAV) does not interfere with the receptor complex, indicating that the complex is not PDZ-dependent. MCF7 breast cancer cells express GPR30, β1AR, MAGUKs, and AKAP5 in the plasma membrane, and co-immunoprecipitation revealed that these proteins exist in close proximity also under native conditions. Furthermore, expression of GPR30 in MCF7 cells constitutively and PDZ-dependently inhibits β1AR-mediated cAMP production. AKAP5 also inhibits β1AR-mediated cAMP production, which is not additive with GPR30-promoted inhibition. These results argue that GPR30 and β1AR form a PDZ-independent complex in MCF7 cells through which GPR30 constitutively and PDZ-dependently inhibits β1AR signaling via receptor interaction with MAGUKs and AKAP5.
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47. |
- Tutzauer, Julia, et al.
(författare)
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Ligand-independent G protein-coupled estrogen receptor/G protein-coupled receptor 30 activity : Lack of receptor-dependent effects of G-1 and 17b-estradiol
- 2021
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Ingår i: Molecular Pharmacology. - 0026-895X. ; 100:3, s. 271-282
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Tidskriftsartikel (refereegranskat)abstract
- G protein-coupled receptor 30 (GPR30) is a membrane receptor reported to bind 17b-estradiol (E2) and mediate rapid nongenomic estrogen responses, hence also named G protein-coupled estrogen receptor. G-1 is a proposed GPR30-specific agonist that has been used to implicate the receptor in several pathophysiological events. However, controversy surrounds the role of GPR30 in G-1 and E2 responses. We investigated GPR30 activity in the absence and presence of G-1 and E2 in several eukaryotic systems ex vivo and in vitro in the absence and presence of the receptor. Ex vivo activity was addressed using the caudal artery from wild-type (WT) and GPR30 knockout (KO) mice, and in vitro activity was addressed using a HeLa cell line stably expressing a synthetic multifunctional promoter (nuclear factor jB, signal transducer and activator of transcription, activator protein 1)-luciferase construct (HFF11 cells) and a human GPR30-inducible T-REx system (T-REx HFF11 cells), HFF11 and human embryonic kidney 293 cells transiently expressing WT GPR30 and GPR30 lacking the C-terminal PDZ (postsynaptic density-95/discs-large/zonula occludens-1 homology) motif SSAV, and yeast Saccharomyces cerevisiae transformed to express GPR30. WT and KO arteries exhibited similar contractile responses to 60 mM KCl and 0.3 mM cirazoline, and G-1 relaxed both arteries with the same potency and efficacy. Furthermore, expression of GPR30 did not introduce any responses to 1 mM G-1 and 0.1 mM E2 in vitro. On the other hand, receptor expression caused considerable ligand-independent activity in vitro, which was receptor PDZ motif-dependent in mammalian cells. We conclude from these results that GPR30 exhibits ligand-independent activity in vitro but no G-1- or E2-stimulated activity in any of the systems used. SIGNIFICANCE STATEMENT Much controversy surrounds 17b-estradiol (E2) and G-1 as G protein-coupled receptor 30 (GPR30) agonists. We used several recombinant eukaryotic systems ex vivo and in vitro with and without GPR30 expression to address the role of this receptor in responses to these proposed agonists. Our results show that GPR30 exhibits considerable ligand-independent activity in vitro but no G-1- or E2-stimulated activity in any of the systems used. Thus, classifying GPR30 as an estrogen receptor and G-1 as a specific GPR30 agonist is unfounded.
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48. |
- Tutzauer, Julia, et al.
(författare)
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Plasma membrane expression of G protein-coupled estrogen receptor (GPER)/G protein-coupled receptor 30 (GPR30) is associated with worse outcome in metachronous contralateral breast cancer
- 2020
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 15:4
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Tidskriftsartikel (refereegranskat)abstract
- Background G protein-coupled estrogen receptor (GPER), or G protein-coupled receptor 30 (GPR30), is reported to mediate non-genomic estrogen signaling. GPR30 associates with breast cancer (BC) outcome and may contribute to tamoxifen resistance. We investigated the expression and prognostic significance of GPR30 in metachronous contralateral breast cancer (CBC) as a model of tamoxifen resistance. Methods Total GPR30 expression (GPR30TOT) and plasma membrane-localized GPR30 expression (GPR30PM) were analyzed by immunohistochemistry in primary (BC1; nBC1 = 559) and contralateral BC (BC2; nBC2 = 595), and in lymph node metastases (LGL; nLGL1 = 213; nLGL2 = 196). Death from BC (BCD), including BC death or death after documented distant metastasis, was used as primary end-point. Results GPR30PM in BC2 and LGL2 were associated with increased risk of BCD (HRBC2 = 1.7, p = 0.03; HRLGL2 = 2.0; p = 0.02). In BC1 and BC2, GPR30PM associated with estrogen receptor (ER)-negativity (pBC1<0.0001; pBC2<0.0001) and progesterone receptor (PR)-negativity (pBC1 = 0.0007; pBC2<0.0001). The highest GPR30TOT and GPR30PM were observed in triple-negative BC. GPR30PM associated with high Ki67 staining in BC1 (p<0.0001) and BC2 (p<0.0001). GPR30TOT in BC2 did not associate with tamoxifen treatment for BC1. However, BC2 that were diagnosed during tamoxifen treatment were more likely to express GPR30PM than BC2 diagnosed after treatment completion (p = 0.01). Furthermore, a trend was observed that patients with GPR30PM in an ER-positive BC2 had greater benefit from tamoxifen treatment. Conclusion PM-localized GPR30 staining is associated with increased risk of BC death when expressed in BC2 and LGL2. Additionally, PM-localized GPR30 correlates with prognostic markers of worse outcome, such as high Ki67 and a triple-negative subtype. Therefore, PM-localized GPR30 may be an interesting new target for therapeutic exploitation. We found no clear evidence that total GPR30 expression is affected by tamoxifen exposure during development of metachronous CBC, or that GPR30 contributes to tamoxifen resistance.
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49. |
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50. |
- Windahl, Sara H, 1971, et al.
(författare)
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The role of the G protein-coupled receptor GPR30 in the effects of estrogen in ovariectomized mice.
- 2009
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Ingår i: American journal of physiology. Endocrinology and metabolism. - : American Physiological Society. - 0193-1849 .- 1522-1555. ; 296:3
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Tidskriftsartikel (refereegranskat)abstract
- In vitro studies suggest that the membrane G protein-coupled receptor GPR30 is a functional estrogen receptor (ER). The aim of the present study was to determine the possible in vivo role of GPR30 as a functional ER primarily for the regulation of skeletal parameters, including bone mass and longitudinal bone growth, but also for some other well-known estrogen-regulated parameters, including uterine weight, thymus weight, and fat mass. Three-month-old ovariectomized (OVX) GPR30-deficient mice (GPR30(-/-)) and wild-type (WT) mice were treated with either vehicle or increasing doses of estradiol (E(2); 0, 30, 70, 160, or 830 ng.mouse(-1).day(-1)). Body composition [bone mineral density (BMD), fat mass, and lean mass] was analyzed by dual-energy-X ray absorptiometry, while the cortical and trabecular bone compartments were analyzed by peripheral quantitative computerized tomography. Quantitative histological analyses were performed in the distal femur growth plate. Bone marrow cellularity and distribution were analyzed using a fluorescence-activated cell sorter. The estrogenic responses on most of the investigated parameters, including increase in bone mass (total body BMD, spine BMD, trabecular BMD, and cortical bone thickness), increase in uterine weight, thymic atrophy, fat mass reduction, and increase in bone marrow cellularity, were similar for all of the investigated E(2) doses in WT and GPR30(-/-) mice. On the other hand, E(2) treatment reduced longitudinal bone growth, reflected by decreased femur length and distal femur growth plate height, in the WT mice but not in the GPR30(-/-) mice compared with vehicle-treated mice. These in vivo findings demonstrate that GPR30 is not required for normal estrogenic responses on several major well-known estrogen-regulated parameters. In contrast, GPR30 is required for a normal estrogenic response in the growth plate.
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