Angiotensin IIと物理的圧の接着因子発現に及ぼす協調作用 : 培養メサンジウム細胞での検討

摘要

Objective: Mesangial cell dysfunction is produced in response to various stimuli. The role of both physical factors and humoral mediators in mesangial cell have been investigated, however, there are few studies examining the synergistic action of these factors. In the present study, to investigate the role adhesion molecules in the regulation of cellular function, we assessed the effect of pressure and angiotensin II in the production of endotelin-1 (ET-1) and nitric oxide (NO) from cultured rat mesangial cells (RMC). Furthermore, the effect of antisense of E-selectin in the production of ET-1 and NOx in cultured RMC were examined. Design and Methods: Rat mesangial cells were harvested from Sprague Dawly (SD) rats. Rat mesangial cells were plated onto 75-cm2 flasks. A pressure loading apparatus was set up by using compresses He gas. Transmural pressure (0, 50, 100 or 200 mmHg) was applied for 24 hours with angiotensin II (10-6, 10-7 and 10-8 M). Every 6 hours, cultured media was collected for measurements of ET-1 and NOx. The expression of ecNOS-mRNA was measured by using RT-PCR. The expression of adhesion molecules (integrin α5β1, VCAM1, E-selectin) in the cultured RCM were examined by using immunofluorescens method. The antisense of E-selection was added in the cultured RMC and measured the expression of ET-1 and NOx. Then angiotensin type I receptor blocker (CS866) was added onto cultured media. Results: Either transmural pressure or angiotensin II alone did not induce any significant changes in ET-1 concentration and expression of adhesion molecules. The expression of E-selectin appeared in RCM in accordance with the levels of transmural pressure and the concentrations of angiotensin II. Combined treatment with transmural pressure and angiotensin II produced a marked elevation of ET-1 and reduction of expression of ecNOS-mRNA. Administration of antisense of E-selection in RCM induced the reduction of ET-1 accompanied with the suppression of the expression of E-selection. However there was no significant change in the expression of ecNOS-mRNA. Incubation with CS866 in RMC, adhesion molecule of E-selectin disappeared accompanied with the reduction of ET-1. Conclusions: In conclusion, synergistic action of transmural pressure and renin-angiotensin system may induce the expression of adhesion molecule E-selection accompanied with the increase of ET-1 and reduction of NO in the cultured RMC. These findings suggest that RMC can produce E-selection in response to synergistic action of intraglomerular pressure and angiotensin II and resulted in nephrosclerosis. E-selection plays an important role in the regulation of the production of ET-1 in cultured media. On the contrary, NO production was not related to the expression of E-selection.