The Role Of PcG In Regulating Of Hyaluronic Acid Synthesize In Human Skin Aging Induced By Ultraviolet (UVA)

Skin gets aged in two forms including natural aging and optical radiation aging,and ultraviolet radiation is the most important risk factor in skin aging. Chronicaccumulation of ultraviolet radiation can directly or indirectly activate aging relatedmolecular signaling pathways, thus inhibiting the synthesis of collagen and hyaluronicacid and eventually causes aging of the skin and related changes like wrinkle formation.Many reports have proved that natural aging and ultraviolet (UVA) induced aging havea common molecular regulation pathway, thus we can establish a simulation model ofaging skin using ultraviolet radiation.With the skin aging, the most important performance is the formation of skinwrinkles.The main reason for the formation of wrinkles is that skin collagen andhyaluronic acid synthesis of the dermis is decreasing, and in this process fibroblast cellis the most important components of the dermis. As a major producer of extracellularmatrix scaffold in the dermis, fibroblast cell is involved in many dynamic process andinteract with other cells in the regulation of the various cellular processes of dynamicbalance, however the hyaluronic acid synthesis regulation mechanism in light-inducedskin aging needs further research.In this test,we used the human skin fibroblasts and embryonic skin fibroblasts asexperimental object,and the ultraviolet irradiation was used to establishe light-inducedaging model.We took application of CCK8, flow test and RT-PCR technique to observecell proliferation activity,cell apoptosis and change of cell aging related molecularsynthesize by different doses of UV radiation at different time after the radiation, aimingat discovering the skin aging mechanism indued by ultraviolet radiation and theregulatory role of PcG protein in skin aging and the differences between human skin fibroblasts and embryonic skin fibroblasts.The following works have been done in this research:1. The effect of the UV irradiation on proliferation of the HSF(human skinfibroblast) and ESF(embryonal skin fibroblast):Cells were irradiated by UVA(365nm) at different doses of0,1,2,4,8J/cm2and thenthe proliferations were detected by the CCK-8on0,12,24hours after the irriadiation.We found that the lower proliferation of the cells from the higher dose in both cellsexcept the HSF irradiated at dose of1J/cm2.And ESF has lower survival but higherrepair capacity than HSF.2. The effect of the UV irradiation on apoptosis of the HSF and ESF:Cells were irradiated by different doses of UVA(365nm) at0,1,4,8J/cm2and thenthe apoptosis were detected by flow cytometer on0,12,24hours after the irriadiation.We found that HSF hast higher apoptosis at dose of4J/cm2and lower apoptosis at doseof8J/cm2.ESF has higher apoptosis at both dose of4J/cm2and8J/cm2.3. The effect of the UV irradiation on synthesiz of hyaluronic acid in HSF andESF:(1) Cells were irradiated by different doses of UVA(365nm) at0,1,4,8J/cm2andthen the HA were detected by ELISA on12,24hours after the irriadiation. We foundthat both HSF and ESF has lower synthesiz of hyaluronic except HSF irradiated at doseof8J/cm2.(2) Cells were irradiated by different doses of UVA(365nm) at0,1,4,8J/cm2andthen the mRNA expression of HAS and HYAL(hyaluronoglucosaminidase) weredetected by RT-PCR(Realtime-polymerase chain reaction) on12hours after theirriadiation. We found that in HSF, HAS2,HAS3and HYAL1were up-regulated,HAS3was down-regulated, and HAYL2was down-regulater when irradiated at dose of8J/cm2and up-regulater when irradiated at dose of1J/cm2and4J/cm2. On the contrary in ESF,HAS2and HAS3were down-regulated,HAYL1was up-regulated,and HAYL2was up-regulated at dose of1J/cm2and down-regulated at dose of4J/cm2and8J/cm2.4. The effect of the UV irradiation on expression of PcG (Polycomb group): Cells were irradiated by different doses of UVA (365nm) at0,1,4,8J/cm2and thenthe mRNA expression of PcG were detected by RT-PCR (Realtime-polymerase chainreaction) on12hours after the irriadiation. We found lower PcG expression at higherdose of UVA in ESF. While in HSF, PcG was down-regulated at dose of4J/cm2and up-regulated at dose of8J/cm2.These indicate that PcG plays a role in regulating of hyaluronic acid synthesize inhuman skin aging induced by ultraviolet (UVA),and there is exact difference betweenHSF and ESF.