| 1. |
- Cao, Lei, et al.
(author)
-
Cigarette smoke upregulates rat coronary artery endothelin receptors in vivo.
- 2012
-
In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:3
-
Journal article (peer-reviewed)abstract
- Cigarette smoking is a strong cardiovascular risk factor and endothelin (ET) receptors are related to coronary artery diseases. The present study established an in vivo secondhand smoke (SHS) exposure model and investigated the hypothesis that cigarette smoke induces ET receptor upregulation in rat coronary arteries and its possible underlying mechanisms.
|
|
| 2. |
|
|
| 3. |
- Cao, Lei, et al.
(author)
-
Secondhand smoke exposure induces Raf/ERK/MAPK-mediated upregulation of cerebrovascular endothelin ETA receptors.
- 2011
-
In: BMC Neuroscience. - : Springer Science and Business Media LLC. - 1471-2202. ; 12
-
Journal article (peer-reviewed)abstract
- BACKGROUND: Cigarette smoking enhances the risk of stroke. However, the underlying molecular mechanisms are largely unknown. The present study established an in vivo rat secondhand cigarette smoking (SHS) model and examined the hypothesis that SHS upregulates endothelin receptors with increased cerebrovascular contraction via the Raf/extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinases (MAPK) pathway. RESULTS: Rats were exposed to SHS for up to 8 weeks. The cerebral artery vasoconstriction was recorded by a sensitive myograph. The mRNA and protein expressions for endothelin receptors in cerebral arteries were studied by real-time PCR and Western blot. Compared to fresh air exposed rats, cerebral arteries from SHS rats exhibited stronger contractile responses (P < 0.05) mediated by endothelin type A (ETA) receptors. The expressions of mRNA and protein for ETA receptors in the cerebral arteries from SHS rats were higher (P < 0.05) than that in control. SHS did not affect endothelin type B (ETB) receptor-mediated contractions, mRNA or protein levels. The results suggest that SHS upregulates ETA, but not ETB receptors in vivo. After SHS exposure, the mRNA levels of Raf-1 and ERK1/2, the protein expression of phosphorylated (p)-Raf-1 and p-ERK1/2 were increased (P < 0.05). Raf-1 inhibitor, GW5074 suppressed the enhanced ETA receptor-mediated contraction, mRNA and protein levels induced by SHS. In addition, GW5074 inhibited the SHS-caused increased mRNA and phosphorylated protein levels of Raf-1 and ERK1/2, suggesting that SHS induces activation of the Raf/ERK/MAPK pathway. CONCLUSIONS: SHS upregulates cerebrovascular ETA receptors via the Raf/ERK/MAPK pathway, which provides novel understanding of mechanisms involved in SHS-associated stroke.
|
|
| 4. |
- Lei, Ying, et al.
(author)
-
Enhanced airway smooth muscle cell thromboxane receptor signaling via activation of JNK MAPK and extracellular calcium influx.
- 2011
-
In: European Journal of Pharmacology. - : Elsevier BV. - 1879-0712 .- 0014-2999. ; 650:2-3, s. 629-638
-
Journal article (peer-reviewed)abstract
- Thromboxane is a key inflammatory mediator and potent airway constrictor. It acts on thromboxane A(2) (TP) receptors and contributes to airway inflammation and airway hyperresponsiveness that is the characteristic feature of asthma. The present study was designed to study TP receptor signaling in airway smooth muscle cells by using an organ culture model and a set of selective pharmacological inhibitors for mitogen-activated protein kinase (MAPK) and calcium signal pathways. Western-blot, immunohistochemistry, myograph and a selective TP receptor agonist U46619 were used for examining TP receptor signal proteins and function. Organ culture of rat bronchial segments for up to 48h induces a time-dependently increased airway contractile response to U46619. This indicates that organ culture increases TP receptor signaling in the airway smooth muscle cells. The enhanced bronchial contraction was attenuated by the inhibition of c-Jun N-terminal kinase (JNK) MAPK activity, chelation of extracellular calcium and calcium channel blocker nifedipine, suggesting that JNK MAPK activity and elevated intracellular calcium level are required for the TP receptor signaling. In conclusion, airway smooth muscle cell TP receptor signaling occurs via JNK MAPK activity and the elevation of extracellular calcium influx, which may provide knowledge for understanding the signaling pathway responsible for the modulation of TP receptor mediated airway hyperresponsiveness to thromboxane.
|
|
| 5. |
- Lei, Ying, et al.
(author)
-
Up-regulation of bradykinin receptors in rat bronchia via IkappaB kinase-mediated inflammatory signaling pathway.
- 2010
-
In: European Journal of Pharmacology. - : Elsevier BV. - 1879-0712 .- 0014-2999. ; 634:1-3, s. 149-161
-
Journal article (peer-reviewed)abstract
- IkappaB kinase (IKK)-mediated intracellular signaling mechanisms may be involved in airway hyperresponsiveness through up-regulation of bradykinin receptors. This study was designed to examine if organ culture of rat bronchial segments induces airway hyperresponsiveness to bradykinin and if inhibition of IKK can abrogate the airway hyperresponsiveness to bradykinin via suppressing the expression of bradykinin B(1) and B(2) receptors. Rat bronchi were isolated and cut into ring segments. The segments were then organ cultured in the presence or absence of IKK inhibitors, BMS-345541 or TPCA-1. des-Arg(9)-bradykinin (B(1) receptor agonist) - and bradykinin (B(2) receptor agonist) - induced contractions of the segments were monitored by a sensitive organ bath system. The expression of bradykinin B(1) and B(2) receptors, inflammatory mediators and phosphorylated IKK were studied by a real-time PCR and/or by immunohistochemistry using confocal microscopy. Organ culture of the bronchial segments induced a time-dependent up-regulation of bradykinin B(1) and B(2) receptors. The IKK inhibitors abolished the organ culture-induced up-regulation of bradykinin B(1) and B(2) receptor-mediated contractions in a concentration-dependent manner. This was paralleled with inhibition of IKK activity (phosphorylation), reduced mRNA and protein expressions of bradykinin B(1) and B(2) receptors and decreased mRNA expression of inflammatory mediators (interleukin-6, inducible nitric oxide synthase, cyclooxygenase 2 and matrix metalloproteinase 9). Our results show that organ culture induces IKK-mediated inflammatory changes in airways which subsequently results in airway hyperresponsiveness to bradykinin via the up-regulated bradykinin receptors. Thus, IKK inhibition might be a promising approach for treatment of airway inflammation and airway hyperresponsiveness that are often seen in asthmatic patients.
|
|
| 6. |
- Lindstedt, Isak, et al.
(author)
-
Increased perfusion pressure enhances the expression of endothelin (ETB) and angiotensin II (AT1, AT2) receptors in rat mesenteric artery smooth muscle cells.
- 2009
-
In: Blood Pressure. - : Informa UK Limited. - 0803-7051 .- 1651-1999. ; 18:1, s. 78-85
-
Journal article (peer-reviewed)abstract
- In the present study, we hypothesized that changes in perfusion pressure result in altered expression of mRNA and protein encoding for the ETA-, ETB-, AT1- and AT2-receptors in rat mesenteric vessels. Segments of the rat mesenteric artery were cannulated with glass micropipettes, pressurized and luminally perfused in a perfusion chamber. After either exposure to no ("organ culture" (0 mmHg)), normal (85/75 mmHg) or high pressure (160/150 mmHg) at constant flow for 1-17 h, the vessel segments were snap frozen and real-time polymerase chain reaction was performed to quantify the ET- and AT-receptor mRNA content, or immersed in a fixative solution, dehydrated, frozen, cut in a cryostat and immunohistology stained for ET- and AT-receptor protein. The mRNA expressions of ETB and of AT2 were significantly enhanced in vessels exposed to high perfusion pressure, compared with normal and no perfusion pressure at 4 h. In concordance, AT1-, AT2- and ETB-receptor proteins were up-regulated at 17 h of high perfusion pressure. In conclusion, the results from our rat perfusion model suggest a more important role of shear stress than pure pressure alone and may serve as a surrogate model for studies designed to investigate hypertension mechanisms.
|
|
| 7. |
- Xie, Yan-Hua, et al.
(author)
-
Nuclear Factor-kappaB-Mediated Endothelin Receptor Up-Regulation Increases Renal Artery Contractility in Rats
- 2013
-
In: Basic & Clinical Pharmacology & Toxicology. - : Wiley. - 1742-7843 .- 1742-7835. ; 113:6, s. 401-410
-
Journal article (peer-reviewed)abstract
- Increased renal artery contractility leads to renal vasospasm and ischaemia as well as kidney damage. This study was designed to examine the hypothesis that organ culture of renal arteries induces transcriptional up-regulation of endothelin type A (ETA) and type B2 (ETB2) receptors in the smooth muscle cells via activation of nuclear factor-kappaB (NF-B) and subsequently increases renal artery contractility. Rat renal artery segments were organ-cultured for 6 or 24hr to increase endothelin receptor-mediated contraction. To dissect molecular mechanisms involved in this process, inhibitors for NF-B signalling pathway (MG-132 and BMS345541), transcription (actinomycin D) and translation (cycloheximide) were used during organ culture. Endothelin receptors were studied using a sensitive myograph (functional contractility), real-time PCR (mRNA analysis) and immunohistochemistry (protein localization). Compared with fresh segments, contractile responses to endothelin-1 (non-selective endothelin receptor agonist) and sarafotoxin 6c (selective ETB receptor agonist) were significantly increased in the segments after 24hr of organ culture; ETB2 receptor-mediated maximal contraction increased from 2.7 +/- 0.5 to 135.3 +/- 5.1 (p<0.001), and potency (pEC(50)) of ETA receptor agonist increased from 8.20 +/- 0.04 to 8.72 +/- 0.07 (p<0.001). This was in parallel with increased corresponding mRNA and protein expression for ETA and ETB2 receptors. BMS345541, MG-132, actinomycin D or cyclohexamide, respectively, suppressed the up-regulation of ETA and ETB2 receptors. Immunostaining performed with specific antibody showed that IB was phosphorylated during organ culture. In conclusion, activation of NF-B mediates up-regulation of ETA and ETB2 receptors and subsequently increases renal artery contractility, which may contribute to renal vasospasm and ischaemia as well as kidney damage.
|
|
| 8. |
- Xie, Yan-hua, et al.
(author)
-
Up-Regulation of G-Protein-Coupled Receptors for Endothelin and Thromboxane by Lipid-Soluble Smoke Particles in Renal Artery of Rat
- 2010
-
In: Basic & Clinical Pharmacology & Toxicology. - : Wiley. - 1742-7843 .- 1742-7835. ; 107:4, s. 803-812
-
Journal article (peer-reviewed)abstract
- Up-regulation of G-protein-coupled receptors (GPCR) plays key roles in renal hypertension and cardiovascular disease pathogenesis. The present study was designed to examine if lipid-soluble cigarette smoking particles (DSP), nicotine and endotoxin (LPS), induce GPCR up-regulation for thromboxane A(2) (TP), endothelin type A (ETA) and type B (ETB) receptors in renal artery, and if intracellular signal mechanisms are involved. Renal artery segments of rats were exposed to DSP, nicotine or LPS, in organ culture for up to 24 hr. The GPCR-mediated contractions were recorded by using a myograph system. Expression of the GPCR was examined by real-time PCR and immunohistochemistry at mRNA and protein levels. Sarafatoxin 6c (S6c, selective ETB receptor agonist), endothelin-1 (ET-1, non-selective ETA and ETB receptor agonist) and 9,11-Dideoxy-9a,11a-methanoepoxy prostaglandin F-2a (U46619, a TP receptor agonist) induced contractions were significantly increased after the arterial segments exposed to DSP in a concentration-dependent (0.1-0.4 mu l/ml) manner, and S6c also induced a time-dependent contraction, compared to control (dimethyl sulfoxide). This was in parallel with enhanced mRNA expression for ETB receptor but not ETA and TP receptors, while increased protein expression for ETA, ETB and TP receptors was seen. The specific nuclear factor-kappa B (NF-kappa B) signal pathway inhibitor BMS345541 was applied to link DSP effects to the GPCR up-regulation. It totally abolished ETB receptor up-regulation, but not ETA and TP receptor up-regulations. Our results suggest that DSP transcriptionally up-regulated ETB receptor expression in rat renal artery via NF-kappa B signal pathways, whereas up-regulation of ETA and TP receptor-mediated contraction may involve post-transcriptional mechanisms.
|
|
| 9. |
- Xu, Cang-Bao, et al.
(author)
-
D-erythro-N,N-dimethylsphingosine inhibits bFGF-induced proliferation of cerebral, aortic and coronary smooth muscle cells.
- 2002
-
In: Atherosclerosis. - 1879-1484. ; 164:2, s. 237-243
-
Journal article (peer-reviewed)abstract
- The role of sphingosine kinase (SphK) on basic fibroblast growth factor (bFGF)-induced proliferation of cerebral, aortic and coronary smooth muscle cells (SMC) was addressed using D-erythro-N,N-dimethylsphingosine (DMS), an inhibitor of SphK which blocks conversion of sphingosine to sphingosine-1-phosphate (S1P). DMS concentration-dependently reduced the bFGF-induced proliferation of rat cerebral and aortic, and human coronary SMC. This suggests that SphK is one of the key enzymes in the mitogenic response to bFGF in vascular SMC as supported by the finding that S1P stimulated proliferation of SMC. Fumonisin B1, a dihydroceramidesynthase inhibitor which blocks the conversion of dihydrosphingosine to seramide, did not affect SMC proliferation induced by bFGF. Staurosporine, an inhibitor of protein kinase C (PKC), inhibited proliferation of SMC induced by bFGF, and both bFGF- and S1P-induced proliferation of SMC was sensitive to pertussis toxin (PTX), an inhibitor of Gi-protein activity. The present study thus demonstrates that SphK, PKC and Gi-protein activities are required for bFGF-mitogenic signaling in SMC. The bFGF mitogenic effect in vascular SMC might at least in part act via the SphK pathway and a Gi-protein.
|
|
| 10. |
- Xu, Cang-Bao, et al.
(author)
-
Lipid soluble smoke particles up-regulate vascular smooth muscle ETB receptors via activation of mitogen activating protein kinases and NF-kappaB pathways.
- 2008
-
In: Toxicological Sciences. - : Oxford University Press (OUP). - 1096-0929 .- 1096-6080. ; 106:2, s. 546-555
-
Journal article (peer-reviewed)abstract
- Cigarette smoke is a strong risk factor for cardiovascular disease. However, the underlying molecular mechanisms that lead to cigarette smoke-associated cardiovascular disease remain elusive. With functional and molecular methods, we demonstrate for the first time that lipid soluble cigarette smoke particles (DSP) increased the expression of endothelin type B (ET(B)) receptors in arterial smooth muscle cells. The increased ET(B) receptors in arterial smooth muscle cells was documented as enhanced contractility (sensitive myograph technique), elevated levels of ET(B) receptor mRNA (quantitative real-time PCR) and protein expressions (immunohistochemistry and Western blotting). Intracellular signalling was studied with Western blotting and phosphoELISA; this revealed that DSP induced extracellular-regulated protein kinase 1 and 2 (ERK1/2), p38 and nuclear factor-kappaB (NF-kappaB) phosphorylation within 3 hours. Blocking ERK1/2, p38 or NF-kappaB activation by their specific inhibitors significantly attenuated the DSP-induced up-regulation of ET(B) receptor-mediated contraction and both ET(B) receptor mRNA and protein expression. In addition, dexamethasone abolished the DSP-induced up-regulation of ET(B) receptor-mediated contraction. In conclusion, up-regulation of ET(B) receptors by DSP in arterial smooth muscle cells involves activation of mitogen activating protein kinases (ERK1/2 and p38) and the downstream transcriptional factor NF-kappaB pathways.
|
|
