Vascular smooth muscle Jak2 mediates angiotensin II-induced hypertension via increased levels of reactive oxygen species

Annet Kirabo, Patrick N. Kearns, Yagna P. Jarajapu, Jennifer M. Sasser, Suk Paul Oh, Maria B. Grant, Hideko Kasahara, Arturo J. Cardounel, Chris Baylis, Kay Uwe Wagner, Peter P. Sayeski

Research output: Contribution to journalArticle

24 Scopus citations

Abstract

AimsAngiotensin II (Ang II) type AT1 receptors expressed on vascular smooth muscle cells (VSMCs) couple to the Jak2 signalling pathway. However, the importance of this tissue-specific coupling is poorly understood. The purpose of this investigation was to determine the importance of VSMC-derived Jak2 in angiotensin II-mediated hypertension.Methods and resultsThe Cre-loxP system was used to conditionally eliminate Jak2 tyrosine kinase expression within the smooth muscle cells of mice. Following chronic Ang II infusion, the resulting increase in mean arterial pressure (MAP) was significantly attenuated in the Jak2 null mice when compared with littermate controls. The VSMC Jak2 null mice were also protected from the Ang II-induced vascular remodelling. Aortic rings from the VSMC Jak2 null mice exhibited reduced Ang II-induced contraction and enhanced endothelial-dependent relaxation via increased nitric oxide (NO) bioavailability. When compared with controls, the VSMC Jak2 nulls also had lower levels of hydrogen peroxide, Rho kinase activity, and intracellular Ca 2+ in response to Ang II.ConclusionsThe data indicate that VSMC Jak2 expression is involved in the pathogenesis of Ang II-dependent hypertension due to the increased presence of reactive oxygen species (ROS). As such, VSMC-derived Jak2 tyrosine kinase modulates overall vascular tone via multiple, non-redundant mechanisms.

Original languageEnglish (US)
Pages (from-to)171-179
Number of pages9
JournalCardiovascular research
Volume91
Issue number1
DOIs
StatePublished - Jul 1 2011

Keywords

  • Angiotensin II
  • Hypertension
  • Jak2 tyrosine kinase
  • Vascular smooth muscle cell

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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    Kirabo, A., Kearns, P. N., Jarajapu, Y. P., Sasser, J. M., Oh, S. P., Grant, M. B., Kasahara, H., Cardounel, A. J., Baylis, C., Wagner, K. U., & Sayeski, P. P. (2011). Vascular smooth muscle Jak2 mediates angiotensin II-induced hypertension via increased levels of reactive oxygen species. Cardiovascular research, 91(1), 171-179. https://doi.org/10.1093/cvr/cvr059