title: Polypeptide from Chlamys farreri protects HaCaT cells from UVB-induced apoptosis.
abstract: A natural polypeptide from marine Chlamys farreri (a kind of scallop) (PCF), has been recently been found to be an effective photoprotective agent against ultraviolet rays B (UVB)-induced mitochondria damage in normal human fibroblasts. To investigate whether PCF has the antiapoptotic effect on human keratinocytes, in the present study, we established an apoptotic model on HaCaT cell line by means of UVB radiance of 30 mJ/cm(2) and compared the effect of different PCF treatments on UVB-radiated cells. Flow cytometry analyses showed that PCF treatment before UVB-irradiation inhibited UVB-induced apoptosis, the loss of mitochondrial membrane potential (Deltapsim) and the increase of free Ca(2+) level in HaCaT cells. In parallel with these results, UVB-irradiation enhanced activities of caspases-3, 8, 9, while this enhancement was inhibited by PCF treatment prior to irradiation. PCF added after irradiation neither reduced UVB-induced activities of the three caspases nor synergized the effect of pre-added PCF. Cellular ultrastructural features obtained from transmission electron microscopy further confirmed the antiapoptotic effect of PCF pre-treatment. It is concluded that the antiapoptotic effect of PCF is not therapeutic but prophylactic. Caspases-3, 8, 9, Deltapsim and calcium are involved in UVB-induced apoptosis, while prophylactic PCF inhibits apoptosis of UVB-irradiated HaCaT cells by blocking the caspases activities, the Deltapsim lost and the elevation of intracellular free Ca(2+) level.
authors.affiliation: Department of Pharmacology, Medical College, Qingdao University, Qingdao 266021, China.
authors.forename: Chun Bo
authors.initials: CB
authors.lastname: Wang
authors.forename: Mian Qing
authors.initials: MQ
authors.lastname: Huang
authors.forename: Gui Lan
authors.initials: GL
authors.lastname: Tao
authors.forename: Guo Ying
authors.initials: GY
authors.lastname: Yu
authors.forename: Zhi Wu
authors.initials: ZW
authors.lastname: Han
authors.forename: Zhi Hong
authors.initials: ZH
authors.lastname: Yang
authors.forename: Yue Jun
authors.initials: YJ
authors.lastname: Wang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000528:radiation effects; D002118:Calcium / Q000378:metabolism; D020169:Caspases / Q000096:biosynthesis; D002461:Cell Line, Transformed; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D005434:Flow Cytometry; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects* / Q000528:radiation effects / Q000648:ultrastructure; D008564:Membrane Potentials / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D008974:Mollusca / Q000737:chemistry*; D010455:Peptides / Q000302:isolation & purification / Q000494:pharmacology*; D013473:Sunscreening Agents / Q000302:isolation & purification / Q000494:pharmacology*; D014466:Ultraviolet Rays
chemical_list: D010455:Peptides; D013473:Sunscreening Agents; D020169:Caspases; D002118:Calcium