PDF(Pubmed)
Abstract：
Mesotrypsin, encoded by the PRSS3 gene, is a distinctive trypsin isoform renowned for its exceptional resistance to traditional trypsin inhibitors and unique substrate specificity. Within the skin epidermis, this protein primarily expresses in the upper layers of the stratified epidermis and plays a crucial role in processing pro-filaggrin (Pro-FLG). Although prior studies have partially elucidated its functions using primary cultured keratinocytes, challenges persist due to these cells\' differentiation-activated cell death program. In the present study, HaCaT keratinocytes, characterized by minimal endogenous mesotrypsin expression and sustained proliferation in differentiated states, were utilized to further scrutinize the function of mesotrypsin. Despite the ready degradation of the intact form of active mesotrypsin in these cells, fusion with Venus, flanked by a peptide linker, enables evasion from the protein elimination machinery, thus facilitating activation of the Pro-FLG processing system. Inducing Venus-mesotrypsin expression in the cells resulted in a flattened phenotype and reduced proliferative capacity. Moreover, these cells displayed altered F-actin assembly, enhanced E-cadherin adhesive activity, and facilitated tight junction formation without overtly influencing epidermal differentiation. These findings underscore mesotrypsin\'s potentially pivotal role in shaping the characteristic cellular morphology of upper epidermal layers.
摘要：
Mesotrypsin,由PRSS3基因编码，是一种独特的胰蛋白酶同工型，以其对传统胰蛋白酶抑制剂的特殊抗性和独特的底物特异性而闻名。在皮肤表皮内，该蛋白主要在复层表皮的上层表达,在加工成丝蛋白(Pro-FLG)过程中起着至关重要的作用.尽管先前的研究已经部分阐明了使用原代培养的角质形成细胞的功能，由于这些细胞分化激活的细胞死亡程序，挑战仍然存在。在本研究中,HaCaT角质形成细胞,以最小的内源性中胰凝乳蛋白酶表达和分化状态下的持续增殖为特征，被用来进一步审查中胰蛋白酶的功能。尽管在这些细胞中活性中胰凝乳蛋白酶的完整形式容易降解，与金星融合,侧翼有一个肽接头，能够逃避蛋白质消除机器，从而促进Pro-FLG处理系统的激活。在细胞中诱导Venus-mesotrypsin表达导致表型变平和增殖能力降低。此外，这些细胞显示出改变的F-肌动蛋白组装，增强的E-钙粘蛋白粘附活性，并促进紧密连接的形成，而不会明显影响表皮分化。这些发现强调了中胰凝乳蛋白酶在塑造上表皮层特征性细胞形态方面的潜在关键作用。
