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Inhibition of PKR impairs angiogenesis through a VEGF pathway.
- Source :
- American Journal of Physiology: Endocrinology & Metabolism; 3/15/2015, Vol. 308 Issue 6, pE518-E524, 7p
- Publication Year :
- 2015
-
Abstract
- Peripheral artery disease (PAD) is a common clinical problem, and its pathophysiological mechanisms are incompletely understood. Double-stranded RNA-activated protein kinase (PKR) is a ubiquitously expressed serine/threonine protein kinase. Although PKR has been reported in antivirus and the immune system, the role of PKR in vascular function, especially in angiogenesis, is still unclear. PKR<superscript>-/-</superscript> mice were used in our experiments. Blood flow recovery was significantly delayed in PKR<superscript>-/-</superscript> vs. WT mice (Laser Doppler detection, n = 9, P < 0.01), accompanied by 34% reduced CD31-positive stain in ischemic muscle 28 days after procedure (immunohistochemistry, n = 9, P < 0.05). PKR expression decreased in the first 12 h and increased to peak at 24 h in human umbilical vein endothelial cells (HUVECs) in response to hypoxia (Western blot analyses, n = 3, P < 0.05). Accordingly, phospho-PKR expression increased in HUVECs 24 h after treatment with hypoxia (Western blot analyses, n = 3, P < 0.05). Inhibition of PKR (siRNA transfection) reduced microtubule formation (Matrigel tube formation, n = 3, vs. control siRNA, P < 0.05) and migration (wound healing, n = 3, vs. control siRNA, P < 0.05) by 33 and 59%, respectively. Vascular endothelial growth factor (VEGF) expression in ischemic muscle from PKR<superscript>-/-</superscript> mice was significantly decreased by 54% 1 day after procedure (n = 3, P < 0.05, vs. WT) and by 63% 7 days after procedure (n = 3, P < 0.01, vs. WT), respectively. At the same time, VEGF expression in HUVECs decreased by 21% (n = 3, P < 0.05, PKR siRNA vs. control siRNA). These findings demonstrate that PKR mediates angiogenesis through a VEGF pathway, which may form the basis for future intervention of PAD. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 01931849
- Volume :
- 308
- Issue :
- 6
- Database :
- Complementary Index
- Journal :
- American Journal of Physiology: Endocrinology & Metabolism
- Publication Type :
- Academic Journal
- Accession number :
- 101665017
- Full Text :
- https://doi.org/10.1152/ajpendo.00469.2014