Trx2/ASK1信号通路介导线粒体损伤调控天疱疮的发病机制研究

Pemphigus is an autoimmune blistering skin disease, which Specific IgG antibody to keratinocyte desmosome component could bedetected in serum. Skin and mucosa are involved. Keratinocyte apoptosis mediated by mitochondrial injury plays an important role in the pathogenesis of pemphigus. Trx2/ASK1 signaling pathway is a key factor in regulation of mitochondrial injury. Whether or not it is involved in the pathogenesis of pemphigus, no related research reports up to now. Our previous study found that the expression of Trx2 was decreased and the phosphorylation of ASK1 was enhanced in local lesion of pemphigus patients. The serum of pemphigus patients can significantly reduce the expression of Trx2 in keratinocytes, accompany with activation of ASK1 (phosphorylation enhancement) and Keratinocyte apoptosis increased. The content of preliminary work indicated the activation of Trx2/ASK1 signaling pathway may be one of the pathogenesis of pemphigus. In the following study, we first explore the serum of pemphigus patients in vitro chould regulate the progression of mitochondrial injury through the Trx2/ASK1 signaling pathway or not, then lead to the occurrence of pemphigus. At the same time, we will establish the mouse model with acantholysis of pemphigus to verify the direct evidence of progress in regulation of Trx2/ASK1 signaling pathway. This study will contribute to reveal the pathogenesis of pemphigus, and provide a new target for the prevention and treatment of pemphigus.

天疱疮是一种由表皮棘细胞松解引起的自身免疫性、慢性大疱性皮肤病，由IgG介导，皮肤及黏膜均可受累；线粒体损伤介导的细胞凋亡在天疱疮发病中有重要作用，Trx2/ASK1信号通路是调控线粒体损伤的关键因子，但其是否参与天疱疮发病，未见相关研究。我们在前期研究中发现天疱疮患者病损局部Trx2表达降低，ASK1磷酸化增强；天疱疮患者血清在体外明显降低角质成形细胞中Trx2的表达，伴随ASK1的活化（磷酸化增强)及细胞凋亡增多，提示Trx2/ASK1信号通路活化可能是天疱疮致病机制之一；在接下来的研究中，我们首先在体外探索天疱疮患者血清能否通过Trx2/ASK1信号通路调控线粒体损伤，进而导致天疱疮发生；同时建立小鼠棘层松解天疱疮模型，进一步在体内验证Trx2/ASK1信号通路调控天疱疮病程进展的直接证据。本研究将有助于揭示天疱疮的发病机制，为天疱疮的临床防治提供新靶点。

目的:线粒体损伤介导的细胞凋亡事件在寻常型天疱疮(PV)的发病过程中起重要作用。硫氧还蛋白-2 (Trx2)/细胞凋亡信号调节激酶1 (ASK1)信号通路被认为是参与调节线粒体损伤的关键级联。因此，我们研究了Trx2/ASK1信号通路在PV诱导的线粒体损伤中的调控机制。.方法:收集临床PV患者的血清和组织标本，检测氧化应激因子、细胞凋亡和Trx2/ASK1信号转导成员的表达情况。用PV患者血清培养HaCaT细胞，并转染Trx2过表达或沉默载体。进一步评估了活性氧(ROS)、线粒体膜电位(△ψm)和细胞凋亡水平的变化。用Trx2过表达质粒建立及管理PV小鼠模型。观察异位Trx2表达对PV小鼠棘层松解的影响。.结果:在PV患者中检测到一系列的细胞和分子效应,包括（i）氧化应激产物水平升高，（ii）皮肤组织中上皮细胞破坏，（iii）角质形成细胞凋亡诱导，（iv）Trx2蛋白水平降低以及（v）ASK1的磷酸化增强。体外实验证实Trx2可抑制ASK1磷酸化，减轻ROS释放，降低△ψm，降低细胞凋亡率。体内注射Trx2过表达载体也能减轻PV小鼠棘层松解和水疱的形成。.结论:Trx2/ASK1信号通路调控线粒体损伤介导的PV的发生。