title: Inhibition of UVA-induced apoptotic signaling pathway by polypeptide from Chlamys farreri in human HaCaT keratinocytes.
abstract: Chronic UVA irradiation has been reported to induce photoaging and photocarcinogenesis. UVA is a potent inducer of reactive oxygen species (ROS), which can induce various biological processes, including apoptosis. Polypeptide from Chlamys farreri (PCF) is a novel marine active material isolated from the gonochoric Chinese scallop C. farreri. In our previous studies, PCF was found to be an effective antioxidant inhibiting UVA-induced ROS production and a potential inhibitory agent for UVA-induced apoptosis in the human keratinocyte cell line HaCaT. The intracellular mechanisms of how PCF protects HaCaT cells from UVA-induced apoptosis are not understood. Thus, we here investigate the effect of PCF on UVA-induced intracellular signaling of apoptosis. Pretreatment with the ROS scavenger N-acetylcysteine (NAC), the p38 MAPK inhibitor SB203580 or the caspase-3 inhibitor Ac-DEVD-CHO was found to effectively prevent UVA-induced apoptosis, indicating that ROS, p38 MAPK and caspase-3 play important roles in apoptosis. H(2)O(2)-induced apoptosis was attenuated by PCF, suggesting that PCF plays its anti-apoptotic role through its antioxidant activity. In addition, PCF treatment inhibited UVA-induced p38 MAPK activation and caspase-3 activation, as assayed by Western blot analysis and flow cytometry, respectively. Our results suggest that PCF attenuates UVA-induced apoptosis through a reduction of ROS generation and diminished p38 MAPK and caspase-3 activation.
authors.affiliation: Medical College, Qingdao University, Qingdao, China. ljl813@sina.com
authors.forename: Jin-Lian
authors.initials: JL
authors.lastname: Li
authors.forename: Ning
authors.initials: N
authors.lastname: Liu
authors.forename: Xue-Hong
authors.initials: XH
authors.lastname: Chen
authors.forename: Mi
authors.initials: M
authors.lastname: Sun
authors.forename: Chun-Bo
authors.initials: CB
authors.lastname: Wang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects*; D053148:Caspase 3 / Q000378:metabolism / Q000528:radiation effects; D018929:Cell Culture Techniques; D002460:Cell Line; D004396:Coloring Agents; D053938:DNA Fragmentation; D005434:Flow Cytometry; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects*; D049897:Pectinidae; D010455:Peptides / Q000302:isolation & purification / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D004396:Coloring Agents; D010455:Peptides; D053148:Caspase 3