| 1. |
- Shum, Michael, et al.
(författare)
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Angiotensin II type 2 receptor promotes adipocyte differentiation and restores adipocyte size in high-fat/high-fructose diet-induced insulin resistance in rats
- 2013
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Ingår i: American Journal of Physiology. Endocrinology and Metabolism. - : American Physiological Society. - 0193-1849 .- 1522-1555. ; 304:2, s. E197-E210
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Tidskriftsartikel (refereegranskat)abstract
- Angiotensin II type 2 receptor promotes adipocyte differentiation and restores adipocyte size in high-fat/high-fructose diet-induced insulin resistance in rats. Am J Physiol Endocrinol Metab 304: E197-E210, 2013. First published November 13, 2012; doi:10.1152/ajpendo.00149.2012.-This study was aimed at establishing whether specific activation of angiotensin II (ANG II) type 2 receptor (AT2R) modulates adipocyte differentiation and function. In primary cultures of subcutaneous (SC) and retroperitoneal (RET) preadipocytes, both AT2R and AT1R were expressed at the mRNA and protein level. Cells were stimulated with ANG II or the AT2R agonist C21/M24, alone or in the presence of the AT1R antagonist losartan or the AT2R antagonist PD123,319. During differentiation, C21/M24 increased PPA gamma expression in both RET and SC preadipocytes while the number of small lipid droplets and lipid accumulation solely increased in SC preadipocytes. In mature adipocytes, C21/M24 decreased the mean size of large lipid droplets. Upon abolishment of AT2R expression using AT2R-targeted shRNAs, expressions of AT2R, aP2, and PPAR gamma remained very low, and cells were unable to differentiate. In Wistar rats fed a 6-wk high-fat/high-fructose (HFHF) diet, a significant shift toward larger adipocytes was observed in RET and SC adipose tissue depots. C21/M24 treatments for 6 wk restored normal adipocyte size distribution in both these tissue depots. Moreover, C21/M24 and losartan decreased hyperinsulinemia and improved insulin sensitivity impaired by HFHF diet. A strong correlation between adipocyte size area and glucose infusion rate during euglycemic-hyperinsulinemic clamp was observed. These results indicate that AT2R is involved in early adipocyte differentiation, while in mature adipocytes and in a model of insulin resistance AT2R activation restores normal adipocyte morphology and improves insulin sensitivity.
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| 2. |
- Andappan, Murugaiah M. S., et al.
(författare)
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From the First Selective Non-Peptide AT(2) Receptor Agonist to Structurally Related Antagonists
- 2012
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 55:5, s. 2265-2278
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Tidskriftsartikel (refereegranskat)abstract
- A para substitution pattern of the phenyl ring is a characteristic feature of the first reported selective AT(2) receptor agonist M024/C21 (1) and all the nonpeptidic AT(2) receptor agonists described so far. Two series of compounds structurally related to 1 but with a meta substitution pattern have now been synthesized and biologically evaluated for their affinity to the AT(1) and AT(2) receptors. A high AT(2)/AT(1) receptor selectivity was obtained with all 41 compounds synthesized, and the majority exhibited K-i ranging from 2 to 100 nM. Five compounds were evaluated for their functional activity at the AT(2) receptor, applying a neurite outgrowth assay in NG108-15 cells.. Notably, four of the five compounds, with representatives from both series, acted as potent AT(2) receptor antagonists. These compounds were found to be considerably more effective than PD 123,319, the standard AT(2) receptor antagonist used in most laboratories. No AT(2) receptor antagonists were previously reported among the derivatives with a para substitution pattern. Hence, by a minor modification of the agonist 1 it could be transformed into the antagonist, compound 38. These compounds should serve as valuable tools in the assessment of the role of the AT(2) receptor in more complex physiological models.
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| 3. |
- Behrends, Malte, et al.
(författare)
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N-Aryl Isoleucine Derivatives as Angiotensin II AT(2) Receptor Ligands
- 2014
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Ingår i: ChemistryOpen. - : Wiley. - 2191-1363. ; 3:2, s. 65-75
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Tidskriftsartikel (refereegranskat)abstract
- A novel series of ligands for the recombinant human AT(2) receptor has been synthesized utilizing a fast and efficient palladium-catalyzed procedure for aminocarbonylation as the key reaction. Molybdenum hexacarbonyl [Mo(CO)(6)] was employed as the carbon monoxide source, and controlled microwave heating was applied. The prepared N-aryl isoleucine derivatives, encompassing a variety of amide groups attached to the aromatic system, exhibit binding affinities at best with K-i values in the low micromolar range versus the recombinant human AT(2) receptor. Some of the new nonpeptidic isoleucine derivatives may serve as starting points for further structural optimization. The presented data emphasize the importance of using human receptors in drug discovery programs.
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| 4. |
- Gallo-Payet, Nicole, et al.
(författare)
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Angiotensin II, a neuropeptide at frontier between endocrinology and neuroscience : is there a link between the angiotensin II type 2 receptor andAlzheimer’s disease?
- 2011
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Ingår i: Frontiers in Endocrinology. - : Frontiers Media SA. - 1664-2392. ; 2, s. Article 17-
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Tidskriftsartikel (refereegranskat)abstract
- Amyloid-β peptide deposition, abnormal hyperphosphorylation of tau, as well as inflammation and vascular damage, are associated with the development of Alzheimer’s disease (AD). Angiotensin II (Ang II) is a peripheral hormone, as well as a neuropeptide, which binds two major receptors, namely the Ang II type 1 receptor (AT1R) and the type 2 receptor (AT2R). Activation of the AT2R counteracts most of the AT1R-mediated actions, promoting vasodilation, decreasing the expression of pro-inflammatory cytokines, both in the brain and in the cardiovascular system. There is evidence that treatment with AT1R blockers (ARBs) attenuates learning and memory deficits. Studies suggest that the therapeutic effects of ARBs may reflect this unopposed activation of the AT2R in addition to the inhibition of the AT1R. Within the context of AD, modulation of AT2R signaling could improve cognitive performance not only through its action on blood flow/brain microcirculation but also through more specific effects on neurons. This review summarizes the current state of knowledge and potential therapeutic relevance of central actions of this enigmatic receptor. In particular, we highlight the possibility that selective AT2R activation by non-peptide and highly selective agonists, acting on neuronal plasticity, could represent new pharmacological tools that may help improve impaired cognitive performance in AD and other neurological cognitive disorders.
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| 5. |
- Guimond, Marie-Odile, et al.
(författare)
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Comparative functional properties of two structurally similar selective nonpeptide drug-like ligands for the angiotensin II type-2 (AT2) receptor. Effects on neurite outgrowth in NG108-15 cells
- 2012
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Ingår i: European Journal of Pharmacology - Molecular Pharmacology Section. - : Elsevier BV. - 0922-4106 .- 1872-8251. ; 699:1-3, s. 160-171
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Tidskriftsartikel (refereegranskat)abstract
- There is increasing evidence that angiotensin II (Ang II), through binding to the type 2 (AT(2)) receptor may have beneficial effects in various physiological and pathological situations. However, specific action presumably mediated by the angiotensin AT(2) receptor has been hampered by the absence of appropriate selective ligands. The aim of this study was to compare the biological properties of two related and selective drug-like nonpeptide AT(2) ligands, namely an agonist called M024 (also known as Compound 21) and a new ligand, presumably an antagonist, C38/M132, (originally called C38). Properties of the compounds were investigated in NG108-15 cells expressing angiotensin AT(2) receptor and known to develop neurite outgrowth upon Ang II stimulation. NG108-15 cells stimulated for three days with C21/M024 (0.1 or 100 nM) exhibited the same neurite outgrowth as cells stimulated with Ang II (100 nM) while co-incubation of Ang II or C21/M024 with C38/M132 (10 or 100 nM) inhibited their effects, similarly to the angiotensin AT(2) receptor antagonist, PD123319 (10 mu M). As Ang II, C21/M024 induced a Rap1-dependent activation of p42/p44(mapk) whereas preincubation of cells with C38/M132 inhibited p42/p44(mapk) and Rap1 activation induced by Ang II. Three-day treatment with C21/M024 or Ang II decreased cell number in culture, an effect that was rescued by preincubation with C38/M132. Taken together, these results indicate that the nonpeptide ligand C21/M024 is a potent angiotensin AT(2) receptor agonist while C38/M132 acts as an antagonist. These selective nonpeptide angiotensin AT(2) ligands may represent unique and long-awaited tools for the pursuit of in vivo studies.
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| 6. |
- Guimond, Marie-Odile, et al.
(författare)
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Saralasin and Sarile Are AT2 Receptor Agonists
- 2014
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Ingår i: ACS Medicinal Chemistry Letters. - : American Chemical Society (ACS). - 1948-5875. ; 5:10, s. 1129-1132
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Tidskriftsartikel (refereegranskat)abstract
- Saralasin and sarile, extensively studied over the past 40 years as angiotensin II (Ang II) receptor blockers, induce neurite outgrowth in a NG108-15 cell assay to a similar extent as the endogenous Ang II. In their undifferentiated state, these cells express mainly the AT2 receptor. The neurite outgrowth was inhibited by preincubation with the AT2 receptor selective antagonist PD 123,319, which suggests that the observed outgrowth was mediated by the AT2 receptor. Neither saralasin nor sarile reduced the neurite outgrowth induced by Ang II proving that the two octapeptides do not act as antagonists at the AT2 receptor and may be considered as AT2 receptor agonists.
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| 7. |
- Wallinder, Charlotta, et al.
(författare)
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High affinity rigidified AT(2) receptor ligands with indane scaffolds
- 2019
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Ingår i: MedChemComm. - : ROYAL SOC CHEMISTRY. - 2040-2503 .- 2040-2511. ; 10:12, s. 2146-2160
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Tidskriftsartikel (refereegranskat)abstract
- Rigidification of the isobutyl side chain of drug-like AT(2) receptor agonists and antagonists that are structurally related to the first reported selective AT(2) receptor agonist 1 (C21) delivered bioactive indane derivatives. Four enantiomer pairs were synthesized and the enantiomers were isolated in an optical purity >99%. The enantiomers 7a, 7b, 8a, 8b, 9a, 9b, 10a and 10b bind to the AT(2) receptor with moderate (K-i = 54-223 nM) to high affinity (K-i = 2.2-7.0 nM). The enantiomer with positive optical rotation (+) exhibited the highest affinity at the receptor. The indane derivatives 7b and 10a are among the most potent AT(2) receptor antagonists reported so far. As illustrated by the enantiomer pairs 7a/b and 10a/b, an alteration at the stereogenic center has a pronounced impact on the activation process of the AT(2) receptor, and can convert agonists to antagonists and vice versa.
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| 8. |
- Wallinder, Charlotta, et al.
(författare)
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Interconversion of Functional Activity by Minor Structural Alterations in Nonpeptide AT2 Receptor Ligands
- 2015
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Ingår i: ACS Medicinal Chemistry Letters. - : American Chemical Society (ACS). - 1948-5875. ; 6:2, s. 178-182
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Tidskriftsartikel (refereegranskat)abstract
- Migration of the methylene imidazole side chain in the first reported selective drug-like AT, receptor agonist C21/M024 (1) delivered the AT, receptor antagonist C38/M132 (2). We now report that the AT, receptor antagonist compound 4, a biphenyl derivative that is structurally related to 2, is transformed to the agonist 6 by migration of the isobutyl group. The importance of the relative position of the methylene imidazole and the isobutyl substituent is highlighted herein.
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| 9. |
- Wallinder, Charlotta, et al.
(författare)
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Selective angiotensin II AT2 receptor agonists : Benzamide structure–activity relationships
- 2008
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Ingår i: Bioorganic & Medicinal Chemistry. - : Elsevier BV. - 0968-0896 .- 1464-3391. ; 16:14, s. 6841-6849
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Tidskriftsartikel (refereegranskat)abstract
- In the investigation of the structure–activity relationship of nonpeptide AT2 receptor agonists, a series of substituted benzamide analogues of the selective nonpeptide AT2 receptor agonist M024 have been synthesised. In a second series, the biphenyl scaffold was compared to the thienylphenyl scaffold and the impact of the isobutyl substituent and its position on AT1/AT2 receptor selectivity was also investigated. Both series included several compounds with high affinity and selectivity for the AT2 receptor. Three of the compounds were also proven to function as agonists at the AT2 receptor, as deduced from a neurite outgrowth assay, conducted in NG108-15 cells.
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