scholarly journals Enhanced Expression of G(alpha)q and PLCβ1 in Aortic Vascular Smooth Muscle Cells from Spontaneously Hypertensive Rats: Role of Endogenous Angiotensine II and Endothelin‐1

2011 ◽  
Vol 25 (S1) ◽  
Author(s):  
Atef Mohammed Emehdi ◽  
Madhu Anand‐Srivastava
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Spontaneously Hypertensive Rats ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Enhanced Expression ◽  
G Alpha Q

Enhanced expression of Giα proteins contributes to the hyperproliferation of vascular smooth muscle cells from spontaneously hypertensive rats via MAP kinase- and PI3 kinase-independent pathways

2016 ◽  
Vol 94 (1) ◽  
pp. 49-58 ◽  
Author(s):  
Grace Bou Daou ◽  
Yuan Li ◽  
Madhu B. Anand-Srivastava
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Map Kinase ◽  
Vascular Smooth Muscle Cells ◽  
Spontaneously Hypertensive Rats ◽  
Pi3 Kinase ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Enhanced Expression

Vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR) exhibit hyperproliferation, enhanced MAP kinase (MAPK) activity, and overexpression of Giα proteins. This study was undertaken to examine whether the overexpression of Giα proteins contributes to the hyperproliferation of VSMC of SHR through MAPK signaling. The hyperproliferation of VSMC from SHR in the absence and presence of angiotensin II was restored towards those in Wistar–Kyoto (WKY) rats levels by pertussis toxin (PT) treatment. In addition, siRNA knockdown of Giα proteins also resulted in the attenuation of hyperproliferation towards control levels. The overexpression of Giα proteins was also inhibited by MAPK and PI3 kinase (PI3K) inhibitors. In addition, the hyperproliferation and enhanced phosphorylation of ERK1/2 and Akt in VSMC from SHR were attenuated towards WKY levels by the inhibitors of MAPK, PI3K, c-Src, and antioxidants, whereas PT was unable to attenuate the enhanced phosphorylation of ERK1/2 and Akt. Furthermore, 8Br-cAMP and forskolin also attenuated the hyperproliferation of VSMC from SHR. These results suggest that the hyperproliferation of VSMC from SHR may be attributed to the enhanced expression of Giα proteins and increased activation of MAPK and PI3 kinase. However, Giα-mediated hyperproliferation may not be mediated through MAPK- and PI3 kinase-dependent pathways and may involve decreased levels of intracellular cAMP.

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