Background: Henoch-Schönlein purpura (HSP) is a common kind of systematic vasculitis in children characterized by rash, joint pain,abdominal symptoms and renal disease,the detail pathogenesis of HSP has not been elucidated.Acid-sensing ion channels (ASICs) is a proton-gated sodium selective channel that belongs to Degenerin /epithelial Sodium Channel(DEG/ENaC) superfamily,previous research found the expressions of ASIC1a and ASIC3 in the vascular endothelial cells of HSP
This study aims to investigate the molecular mechanisms of silencing of acid-sensing ion channel 1a(ASIC1a) protects the vascular endothelial cells from Henoch-Schonlein purpura(HSP) patients.
Findings:Human dermal microvascular endothelial cells ( HDMVEC) were cultured in vitro, siRNA sequences were designed for the coding region of human ASIC1a gene and HDMVEC cells were transfected with recombinant lentivirus( LV) -sh-ASIC1a. The control group ( NC group) without virus transfection and LV-sh-ASIC1a transfection group ( si-ASIC1a group) were set up. The expression of transfixed ASIC1a gene was detected by RT-PCR. After virus transfection 72 h, serum IgA1from HSP patients and serum IgA1 of normal children were added into HDMVEC cells. ASIC1a and cytoskeleton protein ( sm-α f-actin, MLCK) mRNA and protein expressions were detected by real-time PCR and Western blotting Methods.The binding activity of NF- κB with DNA in HDMVEC was determined by electrophoretic mobility shift assay (EMSA).The whole-cell patch-clamp technique was used to record the current changes and electrophysiological characteristics of ASICs in HDMVEC.
Cytoskeleton protein ( sm-α f-actin, MLCK) mRNA and protein expressions in the group of si-ASIC1a group were significantly increased compared with the NC control group( P＜0.01). The HSP serum and silencing of ASIC1a had no significant effect on the binding activity of NF-κB with DNA in HDMVEC. Compared with the NC control group, the ASICS current and calcium overload of the si-ASIC1A group were reduced( P＜0.01) ．
Conclusions: Silencing ASIC1a can protect HSP vascular endothelial cell injury by inhibiting ASIC1-related calcium influx and reducing the overload of calcium ,not the NF- κB signaling pathway.