Local Augmented Angiotensinogen Secreted from Apoptotic Vascular Endothelial Cells Is a Vital Mediator of Vascular Remodelling

PLoS One. 2015 Jul 6;10(7):e0132583. doi: 10.1371/journal.pone.0132583. eCollection 2015.

Abstract

Vascular remodelling is a critical vasculopathy found in atheromatous diseases and allograft failures. The local renin angiotensin system (RAS) has been implicated in vascular remodelling. However, the mechanisms by which the augmented local RAS is associated with the initial event of endothelial cell apoptosis in injured vasculature remain undefined. We induced the apoptosis of human umbilical vein endothelial cells (HUVECs) and vascular smooth muscle cells (VSMCs) through serum starvation (SS). After the cells were subjected to SS, we found that the mRNA expression of angiotensinogen (AGT) was increased by >3-fold in HUVECs and by approximately 2.5-fold in VSMCs. In addition, the expression of angiotensin-converting enzyme (ACE) mRNA was increased in VSMCs but decreased to 50% in HUVECs during the same apoptotic process. Increases in the expression of AGT protein and angiotensin II (Ang II) were found in a serum-free medium conditioned by HUVECs (SSC). The increased Ang II was suppressed using lisinopril (an ACE inhibitor) treatment. Moreover, the activation of ERK1/2 induced by the SSC in VSMCs was also suppressed by losartan. In conclusion, we first demonstrated that the augmented AGT released from apoptotic endothelial cells acts as a vital progenitor of Ang II to accelerate vascular remodelling, and we suggest that blocking local augmented Ang II might be an effective strategy for restraining intimal hyperplasia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiotensin II / metabolism
  • Angiotensin-Converting Enzyme Inhibitors / pharmacology
  • Angiotensinogen / metabolism*
  • Animals
  • Apoptosis*
  • Cell Line
  • Human Umbilical Vein Endothelial Cells / metabolism*
  • Humans
  • Lisinopril / pharmacology
  • MAP Kinase Signaling System*
  • Mice
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • Muscle, Smooth, Vascular / metabolism
  • Myocytes, Smooth Muscle / metabolism
  • Peptidyl-Dipeptidase A / metabolism
  • Rats
  • Vascular Remodeling*

Substances

  • Angiotensin-Converting Enzyme Inhibitors
  • Angiotensinogen
  • Angiotensin II
  • Lisinopril
  • MAPK1 protein, human
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3
  • Peptidyl-Dipeptidase A

Grants and funding

The sources of funding that supported this study were from the Kaohsiung Medical University (KMU-M099015; www.kmu.edu.tw) and National Science Council Taiwan (NSC98-2815-C-037-017-B; (www.most.gov.tw/mp.aspx)). Both grants were received by Shyh-Jong Wu. Another grant (MOST 103-2314-B-037-007) from National Science Council Taiwan was received by Ya-Ju Hsieh for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.