Functional cross-talk between the cyclic AMP and Jak/STAT signaling pathways in vascular smooth muscle cells.
Angiotensin II (Ang II), the primary effector of the renin-angiotensin system, is a multifunctional hormone that plays an important role in vascular function. In addition to its classical vasoconstrictor action, more recent studies demonstrated that Ang II stimulates the growth of a number of cell types, including vascular smooth muscle cells (SMC) (reviewed in [1-3]). In vivo studies have shown that chronic infusion of Ang II leads to the development of vascular hypertrophy in rats, whereas administration of angiotensin-converting enzyme (ACE) inhibitors or Ang II receptor antagonists prevents or regresses vascular hypertrophy in models of genetic and experimental hypertension [4]. Consistent with in vivo data, several laboratories have shown that Ang II stimulates protein synthesis and induces cellular hypertrophy, but not cell proliferation, in cultured aortic SMC [5-9]. Ang II also induces directed migration (chemotaxis) of vascular SMC [10, 11], although its effect is less prominent than that of platelet-derived growth factor (PDGF). The cellular mechanisms underlying these diverse actions of Ang II are not clearly understood but are likely to involve the activation of distinct signaling pathways.
Meloche
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Research Centre, Centre hospitalier de l'Université de Montréal, Quebec, Canada.
Pelletier
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S
Servant
M J
MJ
D000804:Angiotensin II / Q000502:physiology; D000818:Animals; D000242:Cyclic AMP / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006801:Humans; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000502:physiology*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D051381:Rats; D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2; D011945:Receptors, Angiotensin / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*
D004268:DNA-Binding Proteins; D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2; D011945:Receptors, Angiotensin; D000804:Angiotensin II; D000242:Cyclic AMP; D011505:Protein-Tyrosine Kinases