Abstract: Objective To investigate the effect of low pH on acid-sensing ion channel 1a(ASIC1a) expression in vascular endothelial cell injury induced by serum IgA1 from Henoch-Schonlein purpura (HSP) children and regulatory role of ASIC1a in it. Methods Human dermal microvascular endothelial cells (HDMECs) treated by serum IgA1 from HSP patients were incubated in different pH medium. ASIC1a, destrin and α-SM mRNA expressions in HDMECs were evaluated by real-time quantitative polymerase chain reaction (qPCR). The level of inflammatory cytokines release assay was detected by ELISA method. Moreover destrin and α-SM protein expression in HDMECs was evaluated by western blot. Results The results showed that extracellular acid could induce the upregulation of ASIC1a mRNA expression, stimulate IL-8, NO,TM release and decrease , destrin and α-SM mRNA expression in HDMECs of HSP patients. Furthermore, pharmacological blockade of ASICs attenuated the inflammation response and inhibited the loss of cytoskeletal protein in vascular endothelial cells of HSP patients. Conclusions These findings showed that activation of ASIC1a could involve in the vascular endothelial cell injury of HSP patients. Blocking ASIC1a may have a significant protective effect on the inflammatory injury of vascular endothelial cells.

Key words: Henoch-schonlein purpura(HSP), Acid-sensing ion channels (ASICs), Vascular endothelium cells