托法替布通过JAK/STAT通路抑制系统性硬化症小鼠皮肤纤维化

Tofatinib inhibits skin fibrosis in systemic sclerosis mice via JAK/STAT pathway

目的研究托法替布对博莱霉素诱导的系统性硬化病小鼠皮肤纤维化的抑制作用及机制。方法24只Balb/c小鼠分为4组:为空白组、模型组、早期干预组、晚期干预组,其中模型组、2组干预组博来霉素皮下注射制造系统性硬化症小鼠模型,空白组小鼠皮下注射等量生理盐水,早期干预组自造模开始给予托法替布灌胃处理,晚期干预组自造模第8天给予托法替布灌胃处理。HE染色和Masson染色观察组织病理改变;ELISA方法检测血清IL-6水平;水解法检测皮损组织羟脯氨酸含量;RT-PCR方法测p-JAK1、p-JAK2、p-JAK3、p-STAT3 mRNA的表达;Western blot检测皮损组织中p-JAK1、p-JAK2、p-JAK3、p-STAT3、I型胶原纤维及α-平滑肌蛋白的表达量。结果模型组小鼠相较空白组真皮层增厚,胶原纤维增多,托法替布干预后真皮层变薄,胶原纤维相对减少,早期干预组较晚期干预组真皮层相较对更薄(P<0.05);晚期干预较模型组IL-6水平显著下降(P<0.05);早期干预组较模型组p-JAK2、p-JAK3 mRNA表达量均减少(P<0.05),早期干预组较模型组p-JAK1、p-JAK3、p-STAT3蛋白表达量均减少(P<0.05),早期干预组p-JAK1蛋白表达量较晚期干预组减少(P<0.05)。结论托法替布可通过抑制JAK/STAT信号通路,改善系统性硬化症小鼠皮肤纤维化,且托法替布早期干预起到的抗纤维化作用更明显。

To explore the inhibitory effect of tofatinib on skin fibrosis in bleomycin-induced systemic sclerosis mice and its mechanism,total of 24 Balb/c mice were recruited and divided into blank group,model group,early intervention group and late intervention group.The model group and two intervention groups were subcutaneously injected with bleomycin to induce model of systemic sclerosis,while the blank group was subcutaneously injected with normal saline.The early intervention group was given tofatinib intervention starting from the modeling process,and the late intervention group was given tofatinib intervention on the 8th day after the modeling process.HE and Masson staining were used to observe lesion tissue;ELISA was used to detect of serum level of IL-6;hydrolysis was employed to detect the hydroxyproline content;RT-PCR was used to measure the mRNA expression levels of p-JAK1,p-JAK2,p-JAK3 and p-STAT3;and Western blot was used to detect the expression levels of p-JAK1,p-JAK2,p-JAK3,p-STAT3,type I collagen fiber and A-smooth muscle proteins.Compared with the blank group,the dermis in model group was thicker and collagen fibers were increased.After tofacatib intervention,the dermis was thinned and collagen fibers were relatively reduced.The dermis in early intervention group was thinner than that in late intervention group(P<0.05).The level of IL-6 in late intervention group was significantly lower compared with that in model group(P<0.05).The mRNA expressions of P-JAK2 and P-JAK3 in early intervention group were lower compared with those in model group(P<0.05),and the protein expressions of P-JAK1,P-JAK3 and P-STAT3 in early intervention group were lower compared with those in model group(P<0.05).The expression of P-JAK1 protein in early intervention group was lower than that in late intervention group(P<0.05).In conclusion,tofatinib can suppress skin fibrosis in mice with systemic sclerosis by inhibiting JAK/STAT signaling pathway,and the anti-fibrosis effect of early tofatinib intervention is more obvious.