Pcf Regulation Of Inos / No And Hsp Inhibition Of Uvb-induced Hacat Cells Apoptosis

OBJECTIVE Investigate the mechanism of UVB inducing apoptosis in HaCaT cells via iNOS/NO/HSP/COX-2 pathway and Polypeptide from Chlamys farreri(PCF) protecting HaCaT cells from UVB by UVB-induced apoptotic model of HaCaT cells and iNOS transfected HaCaT cells.METHODS UVB-induced apoptotic model of HaCaT cells was replicated and iNOS transfected model of HaCaT cells was established.Cells were divided into six groups:control group,UVB model group,UVB+1 mmol·L^-1 iNOS inhibitor SMT group,UVB+5.69 mmol·L¹ PCF group,UVB+2.84 mmol·L^-1 PCF group and UVB+1.42 mmol·L^-1 PCF group.Apoptotic rate of cells was determined by flow cytometry PI staining.The time-dependent release of NO was assayed by ESR.The mRNA expression of iNOS was assayed by RT-PCR.Protein expression levels of iNOS,HSP27,HSP70, HSP90 and COX-2 were determined by Western blot analysis.RESULTS The mRNA and protein expression of iNOS could be enhanced by 20 mJ·cm^-2 UVB following high level release of NO (P＜0.01).The expression of HSP70 and HSP90 could also be inhanced(P＜0.05).The expression of iNOS was obviously raised and the release of NO highly increased in iNOS transfeeted HaCaT cells (P＜0.01).1.42～5.69 mmol·L^-1 PCF and SMT significantly inhibited UVB-induced apoptosis(P＜0.05). 1.42～5.69 mmol·L^-1 PCF dose-dependently inhibited iNOS activation,NO release and up-regulate expression of HSP70 and HSP90(P＜0.01) in HaCaT cells irradiated by UVB.CONCLUSION PCF could protect HaCaT cells from UVB-induced apoptosis.Its inhibitory effect on apoptosis may attributes to inhibition of activation of iNOS,production of NO pathway and up-regulation of HSPs.