热损伤角质形成细胞培养上清对真皮成纤维细胞增殖与胶原mRNA表达的影响

目的 观察热损(创)伤后角质形成细胞(KC)培养上清对真皮成纤维细胞(Fb)增殖与胶原mRNA表达的影响.方法 建立KC热损伤模型,收集正常及热损伤12 h后培养上清配制不同浓度的细胞条件培养液;分离培养人正常Fb,实验组分别加入含不同浓度的细胞条件培养液,以单纯DMEM组为对照,采用噻唑蓝(MTT)比色法测定24 h后真皮成纤维细胞增殖;分别以流式细胞仪、实时荧光定量聚合酶链反应(Real-time PCR)测定DMEM组、50%浓度条件培养液组相同时间Fb生长周期及Ⅰ型胶原mRNA表达.结果 细胞增殖测定:热损伤上清(10%、30%、50%、70%)条件培养液组A值(0.151±0.004、0.165±0.009、0.195±0.006、0.202±0.008)均高于正常上清(10%、30%、50%、70%)条件培养液组(0.144±0.004,0.159±0.002,0.180±0.005,0.181±0.006)及对照组(0.144±0.007),除10%浓度组外各实验组A值与对照组比较差异均有统计学意义(t值分别为:4.01、11.42、11.41;P＜0.05),热损伤上清与正常上清条件培养液组比较:50%、70%浓度组间差异有统计学意义(t值分别为:2.03、1.94;P＜0.05);热损伤上清条件培养液50%与70%浓度组间差异无统计学意义(t值为1.34;P＞0.05).细胞周期测定见50%浓度热损伤上清组可明显促进Fb通过G1/S及S/G2限制点,S期及G2/M期细胞与对照组比较增多,G0/G1期细胞与对照组比较明显减少(t值分别为:5.87、11.3、4.86;P＜0.05).Ⅰ型胶原mRNA表达测定中,50%浓度热损伤上清组与对照组比较表达明显上调,差异亦有统计学意义(t=1.72;P＜0.05).结论 热损(创)伤后KC上清液可促进Fb的增殖,同时可上调Ⅰ型胶原mRNA的表达.

Abstract：

Objective To observe the effects of heat injured keratinocyte (KC) supematant on proliferation activity and collagen mRNA expression of the normal fibroblast (Fb).Methods A model of heat injured KC in vitro was reproduced,the supernatants of heat injured KC were collected and used as conditioned medium,and DMEM was used as control medium.Normal Fb were treated with different concentrations of conditioned medium.After treatment for 24 h,the proliferation activity,cell cycle and collagen Ⅰ mRNA levels in treated Fb were measured by using methylthiazol tetrazolium ( MTT),flow cytometry (FCM) and real-time polymerase chain reaction (PCR) techniques.Results As compared with the control group,the absorbance (A) values of MTT in treated groups were significantly increased (t = 4.01,11.42,11.41 ;P ＜0.05),except in 10% group (t = 1.34,P ＞0.05).As compared with normal supernatant treated group (0.159 ± 0.002,0.180 ± 0.005,0.181 ± 0.006),the A values in 50% and 70% conditioned medium group (0.195 ± 0.006,0.202 ± 0.008 ) were significantly increased ( t = 2.03,1.94;P ＜0.05).The 50% conditioned medium increased the percentage of G1 to S and S to G2 phase transit.As compared with control group,the number of cells in S and G2/M phase was increased significantly (t =5.87,11.3;P＜0.05 ) and that in G0/G1 phase decreased significantly ( t = 4.86;P＜0.05 ).Real-time PCR revealed that the collagen Ⅰ mRNA level in 50% conditioned medium group was significantly up-regulated (t= 1.72;P＜0.05 ) as compared with control group.Conclusion Heat injured KC supernatant may promote the proliferation of dermal Fb,and up-regulate the mRNA expression of collagen.