Effects Of Intense Pulse Light On The Human Fibroblasts

Human skin,like all other organs,undergoes chronological aging.In addition,unlike other organs,skin is in direct contact with the environment and therefore undergoes aging as a consequence of environmental damage.The primary environmental factor that causes human skin aging is UV irradiation from the sun.Photoaging of the skin is caused by long affecting of environmental factors at the basis of chronological aging.Deep wrinkling and furrowing,laxity,a leathery appearance,reduced resilience,increased fragility and impaired wound healing.Tthere are changes at the histological level.During the last decade, substantial progress has been made in understanding cellular and molecular mechanisms that bring about chronological aging and photoaging.This emerging information reveals that chronological aging and photoaging share fundamental molecular pathways.These new insights regarding convergence of the molecular basis of chronological aging and photoaging provide exciting new opportunities for the development of new anti-aging therapies.Photorejuvnation technique is a kind of non-denudation and non-virulence teeatment using continuous wave—length intense pulse light(IPL) at low energy density.Intense pulse light is a kind of continuous multi-wave-length non-coherence light,the wave-length coverage between 500～1200nm.With distinct non-virulence the technique was used more and more generally.The safety effect of the therapic became a focus.It has been proved that IPL can enhance the content of collagens in skin in clinical studies,the quantitative analysis of the alteration of collegens has not yet been made.There is few report about other molecular mechanisms of IPL action.The aim of our research is to study the effect of intense pulse light on human fibroblasts,to investigate the possible mechanism.method:1.Fibroblasts were isolated from the foreskin.2.Fibroblasts were divide into groups and were irradiated by certain wave length and designed of irradiation.3.To observe the changer of cell circle the human hypertrophic scar fibroblasts were cultured in vitro.By the means of flowing cytometry; 4.Celluarv morphology observation:The cell morphology changes were observed by light microscopy.5.Cell viability assay:MTT assay was used to detect cellular activity.6.Detection of typeâ… procollagen mRNA:The levels of the typeâ… procollagen mRNA expression of fibroblasts were detected by RT-PCR.7.Proliferating cell nuclear antigen was examined by immunohistochemstry8.The quantitative assay of collagen protain was detect by incorporatedThe main results and conclusions:1.Compared to the sham-irradiation group,there were no noticeable effect on the cell morphology of fibroblasts irradiated by IPL.2.By culturing fibroblasts 24 hours after the IPL irradiation,the cell proliferation activity was measured by MTT assay.The cellular activity were no noticeable change at 6hand 72h.The cellular activity was increased at 24h,48h,72h.and increase with the increment of the energy(P＜0.05).3.By culturing fibroblasts 24 hours after the IPL irradiation,compared with the distribution in cell circle in the irradiation groups and he sham-irradiation groups,it was showed that the percentage of the DNA level in the S and G₂-M phase was higher significantly than in the sham-irradiation group(P＜0.05),while in the percentage of G₁ phase was lower than G₂-M phase(P＜0.05)4.By culturing fibroblasts 24 hours after the IPL irradiation,Proliferating cell nuclear antigen was examined by immunohistochemstry,Compared to the sham-irradiation group Proliferating cell nuclear antigen expression of fibroblasts were increased and increase with the increment of the energy(P＜0.05).5.By culturing fibroblasts 24 hours after the IPL irradiation the quantitative assay of collagen protain was were increased(p＜0.05),There is noticeable change between each group,except 27J/cm² and 34J/cm².6.By culturing fibroblasts 24 hours after the IPL irradiation,typeâ… procollagen mRNA expression levels was detected by RT-PCR,Compared to the sham-irradiation group the level of typeâ… procollagen mRNA expression of fibroblasts were increased(p P＜0.05).There is noticeable change between each group,except 19 J/cm²,27J/cm² and 34J/cm². IPL irraditon can induce the cell proliferation and cell activity in cultured fibroblasts, the expression of the PCNA and typeâ… procollagen mRNA were increase,...