scholarly journals Increased Transient Receptor Potential Channel TRPC3 Expression in Spontaneously Hypertensive Rats

2005 ◽  
Vol 18 (11) ◽  
pp. 1503-1507 ◽  
Author(s):  
D LIU ◽  
A SCHOLZE ◽  
Z ZHU ◽  
R KREUTZ ◽  
M WEHLANDVONTREBRA ◽  
...  
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Transient Receptor Potential Channel ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Transient Receptor

Differential regulation of transient receptor potential melastatin 6 and 7 cation channels by ANG II in vascular smooth muscle cells from spontaneously hypertensive rats

2006 ◽  
Vol 290 (1) ◽  
pp. R73-R78 ◽  
Author(s):  
Rhian M. Touyz ◽  
Ying He ◽  
Augusto C. I. Montezano ◽  
Guoying Yao ◽  
Vladimir Chubanov ◽  
...  
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Cation Channels ◽  
Ang Ii ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Annexin 1 ◽  
Transient Receptor Potential Melastatin ◽  
Transient Receptor

Intracellular Mg2+ depletion has been implicated in vascular dysfunction in hypertension. We demonstrated that transient receptor potential melastatin 7 (TRPM7) cation channels mediate Mg2+ influx in VSMCs. Whether this plays a role in [Mg2+]i deficiency in hypertension is unclear. Here, we tested the hypothesis that downregulation of TRPM7 and its homologue TRPM6 is associated with reduced [Mg2+]i and that ANG II negatively regulates TRPM6/7 in vascular smooth muscle cells (VSMCs) from spontaneously hypertensive rats (SHR). Cultured VSMCs from Wistar Kyoto (WKY) and SHR were studied. mRNA and protein expression of TRPM6 and TRPM7 were assessed by RT-PCR and immunoblotting, respectively. Translocation of annexin-1, specific TRPM7 substrate, was measured as an index of TRPM7 activation. [Mg2+]i was determined using mag fura-2. VSMCs from WKY and SHR express TRPM6 and TRPM7. Basal TRPM6 expression was similar in WKY and SHR, but basal TRPM7 content was lower in VSMCs from SHR vs. WKY. This was associated with significantly reduced [Mg2+]i in SHR cells ( P < 0.01). ANG II time-dependently increased TRPM6 expression, with similar responses in WKY and SHR. ANG II significantly increased TRPM7 expression in WKY ( P < 0.05), but not in SHR. Annexin-1 translocation was reduced 1.5–2-fold in SHR vs. WKY. Our findings demonstrate that TRPM6 and TRPM7 are differentially regulated in VSMCs from SHR and WKY. Whereas TRPM6 is unaltered in SHR, expression of TRPM7 is blunted. This was associated with attenuated annexin-1 translocation and decreased VSMC [Mg2+]i in SHR. Downregulation of TRPM7, but not TRPM6, may play a role in altered Mg2+ homeostasis in VSMCs from SHR.

scholarly journals Upregulation of Transient Receptor Potential Canonical Type 3 Channel via AT1R/TGF-β1/Smad2/3 Induces Atrial Fibrosis in Aging and Spontaneously Hypertensive Rats

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Rongfang He ◽  
Juan Zhang ◽  
Dan Luo ◽  
Yiyan Yu ◽  
Tangting Chen ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Neonatal Rat ◽  
Ang Ii ◽  
Atrial Fibrosis ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Collagen Iii ◽  
Transient Receptor ◽  
O 24

Fibroblast proliferation and migration are central in atrial fibrillation (AF) promoting structure remodeling, which is strongly associated with aging and hypertension. Transient receptor potential canonical-3 channel (TRPC3) is a key mediator of cardiac fibrosis and the pathogenesis of AF. Here, we have observed the increased TRPC3 expression that induced atrial fibrosis which possibly is either mediated by the aging process or related to hypertensive progression. In this study, we measured the pathological structure remodeling by H&E staining, Masson staining, and transmission electron microscope (TEM). The protein expression levels of fibrotic biomarkers and TRPC3 were measured by Western blotting with atrial tissues from normotensive Wistar Kyoto rats (WKY 4m-o (4 months old)), old WKY (WKY 24m-o (24 months old)), spontaneously hypertensive rat (SHR 4m-o (4 months old)), and old SHR (SHR 24m-o (24 months old)). To illuminate the molecular mechanism of TRPC3 in atrial fibrosis of aging rats and SHR, we detected the inhibited role of TRPC3 selective blocker ethyl-1-(4-(2,3,3-trichloroacrylamide) phenyl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylate,pyrazole-3 (Pyr3) on angiotensin II (Ang II) induced fibrosis in neonatal rat atrial fibroblasts. The pathological examination showed that the extracellular matrix (ECM) and collagen fibrils were markedly increased in atrial tissues from aged and hypertensive rats. The protein expressions of fibrotic biomarkers (collagen I, collagen III, and transforming growth factor-β1 (TGF-β1)) were significantly upregulated in atrial tissues from the WKY 24m-o group, SHR 4m-o group, and SHR 24m-o group compared with the WKY 4m-o group. Meanwhile, the expression level of TRPC3 was significantly upregulated in WKY 24m-o and SHR 4m-o atrial tissues compared to WKY 4m-o rats. In isolated and cultured neonatal rat atrial fibroblasts, Ang II induced the atrial fibroblast migration and proliferation and upregulated the expression levels of TRPC3 and fibrotic biomarkers. TRPC3 selected blocker Pyr3 attenuated the migration and proliferation in neonatal rat atrial fibroblasts. Furthermore, Pyr3 significantly alleviated Ang II-induced upregulation of TRPC3, collagen I, collagen III, and TGF-β1 through the molecular mechanism of the TGF-β/Smad2/3 signaling pathway. Similarly, knocking down TRPC3 using short hairpin RNA (shTRPC3) also attenuated Ang II-induced upregulation of TGF-β1. Pyr3 preconditioning decreased Ang II-induced intracellular Ca2+ transient amplitude elevation. Furthermore, AT1 receptor was involved in Ang II-induced TRPC3 upregulation. Hence, upregulation of TRPC3 in aging and hypertension is involved in an atrial fibrosis process. Inhibition of TRPC3 contributes to reverse Ang II-induced fibrosis. TRPC3 may be a potential therapeutic target for preventing fibrosis in aging and hypertension.

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