小环肽C＊HSDGIC＊对中波紫外线诱导的视网膜色素人上皮细胞凋亡的影响

C＊HSDGIC＊ from cyclization of PACAP （1-5） attenuates UVB-induced apoptosis of human retinal pigment epithelial cells

目的:探讨垂体腺苷酸环化酶激活多肽(PACAP)的衍生物小环肽C*HSDGIC*(CHC)对中波紫外线(UVB)诱导的人视网膜色素上皮(RPE)细胞凋亡的影响。方法:Western blotting检测人RPE细胞PACAP 1型受体(PAC1受体)表达;RPE细胞接受0.2 J/cm2UVB照射,随后实验组给予含不同浓度CHC的无血清培养基培养,对照组给予无血清培养基培养;CCK-8法检测CHC对RPE细胞活性的影响;流式细胞术Annexin-V/PI双染检测RPE细胞凋亡情况,JC-1染色检测线粒体膜电位。结果:Western blotting显示RPE细胞表达PAC1受体,CCK-8法显示CHC促细胞活性的最佳浓度为100μmol/L,细胞活性比对照组增加(34.23±3.39)%(P<0.05),抗凋亡最佳浓度也为100μmol/L,细胞活性比对照组增加(20.10±1.48)%(P<0.05)。流式细胞仪分析显示,100μmol/L CHC能使UVB照射后凋亡细胞比例下降(5.63±1.49)%,线粒体去极化细胞比例下降(5.2±0.5)%(P<0.05)。结论:人RPE细胞存在PAC1受体,小环肽C*HSDGIC*对人RPE细胞有促进活性和拮抗凋亡的作用。

AIM ： To investigate the influence of C ＊ HSDGIC ＊ （ CHC）, a cyclopeptide from the cyclization of [ pituitary adenylate cyclase - activating polypeptide 1 - 5, PACAP （ 1 - 5 ） ] with disulfide, on the proliferation and apop- tosis of cultured human retinal pigment epithelial （RPE） cells induced by ultraviolet B （UVB）. METHODS： The expres- sion of PACAP type 1 （ PAC1 ） receptor in human RPE cells was identified by W6stern blotting. The cells were exposed to UVB irradiation and cultured in fresh medium with or without gradient concentrations （ 1 nmol/L to 1 mmol/L） of CHC. The viability of the cells was determined by CCK - 8 assay. The early apoptosis of the ceils was detected by flow cytometry with annexin V and propidium iodide staining. The mitochondrial menbrane potential was detected by flow cytometry with JC - 1 staining. RESULTS ： The PAC1 receptor in human RPE cells was identified by Western blotting. The best results of CHC on the proliferation and anti - apoptosis of human RPE cells were achieved at the concentration of 100 μmolZL, which increased the viability by （34. 23 ±3.39）% and （20. 10 ± 1.48）%, respectively. The percentage of apoptotic ceils was decreased by （5.63 ± 1.49）% with CHC treatment （ 100 μmol/L） after UVB irradiation,and the percentage of mitochon- drium -depolarizing cells was decreased by （5.2 ± 0.5 ）%. CONCLUSION： PAC1 receptor exists in human RPE cells. C ＊ HSDGIC ＊ increases the viability of RPE cells and attenuates UVB - induced apoptosis.