In:
American Journal of Physiology-Endocrinology and Metabolism, American Physiological Society, Vol. 308, No. 6 ( 2015-03-15), p. E518-E524
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 −/− mice were used in our experiments. Blood flow recovery was significantly delayed in PKR −/− 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 −/− 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.
Type of Medium:
Online Resource
ISSN:
0193-1849
,
1522-1555
DOI:
10.1152/ajpendo.00469.2014
Language:
English
Publisher:
American Physiological Society
Publication Date:
2015
detail.hit.zdb_id:
1477331-4
SSG:
12
