Inflammatory Markers in Isolated Endothelial Cells of the Spontaneously Hypertensive Rat

Abstract

Besides an elevated blood pressure, the spontaneously hypertensive rat (SHR) has inflammation, extensive cell injury, microvascular and parenchymal cell dysfunction and vascular lesions. Current evidence in‐vivo shows that both excessive oxidative stress and proteolytic activity are involved, but their source is uncertain, We hypothesize that isolated endothelial cells of the SHR without the involvement of other sources (e.g. adrenal hormones) have elevated levels of oxygen free radical and degrading enzyme. To separate endothelial mechanisms from others, we isolated and cultured rat aortic endothelial cells (RAOEC) of adult SHR and control Wistar rats and propagated them with minimal loss of morphologic and phenotypic characteristics. The expression of oxidative enzymes (xanthine oxidase, XO; nicotinamide adenine dinucleotide phosphate, NADPH), apoptotic enzymes (BAX; BCl‐2) and matrix metalloproteinase (MMP‐9) was determined in cultured second passage RAOEC by immunoperoxidase detection of RAOEC using a standardized avidin/biotin immunolabeling technique and digitally measured by optical intensity. Compared to Wistar endothelium measurements, protein levels of XO, NADPH, MMP‐9 as well as the apoptotic marker BAX, were significantly enhanced in the SHR endothelium with attenuated BCL‐2 protein levels. These results suggest that even isolated aortic endothelium of the SHR has upregulation of proteins as seen previously in‐vivo that may promote inflammation and lesion formation and even in the absence of an elevated blood pressure.(Supported by: 1Grant of “Knowledge Innovation Project”, Academy of Science, China No. KJCX1‐SW‐07, 1Grant of IM0608, CAMS and 2NIH HL‐10081)