Vascular smooth muscle Jak2 deletion prevents angiotensin II-mediated neointima formation following injury in mice
Journal of molecular and cellular cardiology, 2011•Elsevier
The in vitro treatment of vascular smooth muscle cells (VSMC) with angiotensin II (Ang II)
causes Janus kinase 2 (Jak2) to interact with the Ang II type 1 receptor (AT1-R) resulting in
enhanced cell growth. However, the role that Jak2 plays in AT1-R-mediated vascular cell
growth and remodeling in vivo is less clear. We hypothesized that in vivo, Jak2 plays a rate-
limiting role in Ang II-mediated neointima formation following vascular injury. Using the Cre-
loxP system, we conditionally ablated Jak2 from the VSMC of mice. We found that these …
causes Janus kinase 2 (Jak2) to interact with the Ang II type 1 receptor (AT1-R) resulting in
enhanced cell growth. However, the role that Jak2 plays in AT1-R-mediated vascular cell
growth and remodeling in vivo is less clear. We hypothesized that in vivo, Jak2 plays a rate-
limiting role in Ang II-mediated neointima formation following vascular injury. Using the Cre-
loxP system, we conditionally ablated Jak2 from the VSMC of mice. We found that these …
The in vitro treatment of vascular smooth muscle cells (VSMC) with angiotensin II (Ang II) causes Janus kinase 2 (Jak2) to interact with the Ang II type 1 receptor (AT1-R) resulting in enhanced cell growth. However, the role that Jak2 plays in AT1-R-mediated vascular cell growth and remodeling in vivo is less clear. We hypothesized that in vivo, Jak2 plays a rate-limiting role in Ang II-mediated neointima formation following vascular injury. Using the Cre-loxP system, we conditionally ablated Jak2 from the VSMC of mice. We found that these mice are protected from Ang II-mediated neointima formation following iron chloride-induced vascular injury. In addition, the VSMC Jak2 null mice were protected from injury-induced vascular fibrosis and the pathological loss of the contractile marker, smooth muscle α-actin. Finally, when compared to controls, the VSMC Jak2 null mice exhibited significantly less Ang II-induced VSMC proliferation and migration in vitro and in vivo and more apoptosis. These results suggest that Jak2 plays a central role in the causation of Ang II-induced neointima formation following vascular injury and may provide a novel target for the prevention of neointima formation.
Elsevier