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Aim A UVA-induced apoptotic model of HaCaT cells was established to investigate the impact of UVA on c-jun/cyclooxygenase-2(COX-2)and explore related molecular mechanism of the polypeptide from Chlamys farreri(PCF)protecting HaCaT cells from UVA-induced apoptosis.Methods Cells were divided into five groups:control group,UVA model group,UVA+5.69 mmol?L-1 PCF group,UVA+2.84 mmol?L-1 PCF group,UVA+1.42 mmol?L-1 PCF group.Expression level of c-jun was assayed by Real-Time PCR and Western blot.RT-PCR and Western blot analysis were used to determine the mRNA and protein levels of COX-2.Using agarose gel electrophoresis,the effects of PCF and COX-2 inhibitor celecoxib on UVA-induced apoptosis were also investigated.Results PCF and celecoxib had inhibitory effect on 8 J?cm-2 UVA-induced apoptosis of HaCaT cells.COX-2 mRNA and protein levels increased after UVA radiation and the discrepancy was significant compared with control group(P
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Aim To investigate whether the polypeptide from Chlamys farreri(PCF)protected HaCaT cells from UVB-induced apoptosis through Fas-caspase-3 and ROS-cytochrome C.Methods Experiment designs were divided into five groups:control group,UVB model group,UVB+5.69 mmol?L-1PCF group,UVB+2.84 mmol?L-1 PCF group,UVB+1.42 mmol?L-1 PCF group.SiRNA for Fas inhibited Fas expression of UVB-induced HaCaT cells.Using agarose gel electrophoresis,the effects of Fas siRNA and ROS scavenger NAC on UVB-induced apoptosis of HaCaT cells were investigated.Expression levels of cytochrome C andcaspase-3 after inhibitory Fas were determined by Western blot analysis.Intracellular ROS was detected by means of an oxidation-sensitive fluorescent probe(DCFH-DA).Results SiRNA for Fas had inhibitory effects on UVB-induced apoptosis of HaCaT cells and caspase-3 expression.NAC had inhibitory effects on UVB-induced apoptosis of HaCaT cells.PCF inhibited UVB-induced generation of ROS and cytochrome C release dose-dependently.Conclusions PCF protected HaCaT cells from UVB-induced apoptosis.Its inhibitory effect on apoptosis could be attributed to inhibition of Fas-caspase-3 and ROS-cytochrome C pathways.
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Aim To investigate the impact of UVA on expression of tumour necrosis factor related apoptosis inducing ligand (TRAIL) and study the role of TRAIL in UVA-induced apoptosis of HaCaT cells as well as the influence of Polypeptide from Chlamys farreri(PCF)on TRAIL apoptotic pathway induced by UVA.Methods Cells were divided into five groups: control group, UVA model group,UVA+5.69 mmol?L-1 PCF group, UVA+2.84 mmol?L-1 PCF group, UVA+1.42 mmol?L-1 PCF group.Expression level of TRAIL mRNA was assayed by Real-Time PCR.Western blot analysis was used to determine the protein level of TRAIL and caspase-8 activation. The effect of TRAIL neutralization antibody on UVA-induced apoptosis was also investigated.Results TRAIL mRNA and protein levels increased after 8 J?cm-2 UVA radiation and the discrepancy was significant compared with control group(P
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In this paper the protective effect and facillitating reconverting effect of polypeptide from chlamys farreri (PCF) on thymocytes irradiated by 60 Co ? ray were studied using the MTT chromatometry .The results showed that:(1)the damaged extents of thymocytes were increased with the radiative intensity of 60 Co ? ray elevated at the range of 3GY to 9GY compared with that in no-exposure to 60 Co ? ray group.(2)PCF could reduce 60 Co ? ray damage on thymocytes with dose dependence .In the 0.25%~4% concentration range the higher concentration of PCF the stronger protective effects of it ,but the protective effect of PCF at the concentration below 0.5% disappeared while the radiative intensity of 60 Co ? ray was at 9GY.(3)PCF could facilitate the renovation ability of thymocytes after exposure 60 Co ? ray for two hours .And only 2% concentration of PCF showed the facilitating repair process of thymocytes after radiated by 60 Co ? ray for 7 hours .(4) PCF could decrease the activity and facilitate the death of the dying thymocytes after exposure 60 Co ? ray for 19 hours. The results suggested that the protective effect and facilitating repair effect of PCF on the thymocytes damaged by 60 Co ? ray may be mediated by the antisuperoxidation of PCF.
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Objective To study the radioprotective effect of polypeptide from Chlamys farreri (PCF) on ultraviolet B(UVB)-irradiated murine thmocytes in vitro. Methods The murine thymocytes were exposed to UVB radiation. MTT method was used to detect the cell viability. The activities of intracellular glutathione peroxidase (GSH-Px), superoxided dismutase(SOD) and catalase (CAT) were measured. Intracellular reactive oxygen species (ROS) and the effect of PCF on UVB-induced apoptosis were investigated by flow cytometry. Results PCF could greatly enhance the viability of murine thymocyte and markedly promote the activities of GSH-Px, SOD and CAT, while the amount of ROS was decreased. PCF could inhibit UVB-induced thymocyte apoptosis. Conclusion PCF has significant radioprotective effects on UVB-irradiated murine thymocytes in vitro.
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Objective To study the protective effect of PCF against murine thymocytes apoptosis induced by UVB irradiation.Methods The irradiation damage model of thymocytes caused by UVB was established.Cellular ultrastructuralalterations were observed with TEM.The expressions of P53,Bax and Bcl-2 proteins were examined by immunocytochemical technique. The p38 mRNA gene expression was also determined with the technique of in situ hybridization.Results Apoptotic thymocytes were observed after UVB irradiation.The ultrastructural damages of the cells induced by UVB irradiation were reduced by the treatment of PCF.PCF also raised the expression of Bcl-2 gene and decreased the expression of P53,Bax.The mRNA expressions of p38 were decreased in PCF groups.Conclusion PCF showed significant protective effects on UVB-irradiated murine thymocytes in vitro.
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Objective To study the effects of polypeptide from Chlamys farreri(PCF) on PI3K/Akt and ASK1-JNK signal transduction pathway in thymocytes after ultraviolet B radiation.Methods Murine thymocytes were exposed to UVB radiation.The reactive oxygen species(ROS) level in thymocytes was detected by colormatching.The activation of Akt was investigated by western-blot.ASK1,JNK activation,mitochondria memberine potential and DNA ladder were also investigated after pretreatment with or without PI3K/Akt pathway inhibitor LY294002.Results PCF could activate Akt,inhibit the activation of the ASK1 apoptosis pathway in murine thymocyte radiated by UVB.Conclusion PCF decreased ROS level,increased Akt activity and inducing ASK1 degradation leading to the inhibition of ASK1-JNK induced apoptosis.