Toll样受体2对人角质形成细胞增殖的影响

目的 探讨Toll样受体2(TLR2)对体外培养人角质形成细胞增殖的影响.方法 天然配体肽聚糖(PGN)体外活化人角质形成细胞TLR2,用噻唑蓝法检测PGN对角质形成细胞体外增殖的影响,确定最适作用浓度;用实时荧光定量PCR法和Western印迹法分别检测角质形成细胞Ki67、TLR2、核因子(NF)-KBp65及转化生长因子(TGF)-α mRNA和蛋白的表达水平;采用抗体封闭实验分析封闭TLR2对PGN诱导角质形成细胞Ki67、TLR2、NF-KBp65及TGF-α表达的影响.结果 不同浓度的PGN处理角质形成细胞后24 h,在1.25,2.5,5 μg/mL的浓度下细胞较对照组出现明显增殖(P＜0.05). 1.25、2.5和5μg/mL PGN作用于角质形成细胞后24 h,其中1.25和2.5 μg/mL浓度下Ki67 mRNA的表达明显增加,各组Ki67蛋白合成均有增加;各组TLR2 mRNA和蛋白的表达均增加;1.25μg/mL浓度下NF-KBp65 mRNA的表达明显增加,各组细胞核内NF-KBp65蛋白合成均增加;其中1.25和5 μg/mL浓度下TGF-α mRNA和蛋白表达均明显增加(P＜0.05).以抗人TLR2单克隆阻断性抗体封闭TLR2后,PGN诱导的角质形成细胞Ki67、TI,R2、NF-KBp65及TGF-α mRNA和蛋白表达的上调均受到明显抑制(P＜0.05).结论 角质形成细胞TLR2经PGN诱导活化后,可能通过促进NF-KB活化及TGF-α表达而导致角质形成细胞的异常增殖.

Effect of Toll-like receptor 2 on the proliferation of human keratinocytes

Objective To investigate the effect of Toll-like receptor 2(TLR2)on the proliferation of human keratinocytes.Methods Keratinocytes were isolated from the foreskin of children,and subjected to primary culture.Atier 3-5 passages.the kemtinocytes were incubated with various concentrations of peptidoglycan(PGN).a TLR2 agonist.Cell proliferation was detected by MTT colorimetric assay and the suitable concentrations of PGN were determined.The mRNA and protein expressions of Ki67.TLR2.NF-kB p65 and TGF-α were detected by real-time quantitative PCR and Western blot.respectively,in keratinocytes treated witll PGN of 0,1.25,2.5 and 5 μg/mL.Antibody blocking test was utilized to evaluate the effect of blocking TLR2 with specific anti-TLR2 neutralizing monoclonal antibody before incubation with PGN on the expressions of Ki67,TLR2,NF-KB p65 and TGF-α by keratinocytes.Results The proliferation of kemtinocytes was significantly promoted by the incubation with PGN of 1.25,2.5 and 5μg/mL for 24 hours (all P＜0.05),which also increased the expression of Ki67 protein,TLR2 mRNA and protein,and NF-KB p65 protein.Further more,the mRNA expression of Ki67 in keratinocytes was elevated bv PGN of 1.25 and 2.5μg/mL,the mRNA expression of NF-KB p65 elevated by PGN of 1.25μg/mL,and the expressions of TGF-αprotein and mRNA elevated by PGN of 1.25 and 5μg/mL (P＜0.05).The mRNA and protein expressions of Ki67,TLR2,NF-kB p65 and TGF-αwere all inhibited by the blocking of TLR2 before incubation with PGN (a11 P＜0.05).Conclusion Activation of TLR2 bv PGN could induce the over-proliferation of human keratinocytes,likely through promoting NF-rB activation and TGF-α expression.