Chen JingJing, Blechert Oliver, Xiong Shuzhen, Zhan Ping
Nanchang University, Nanchang 330006, China.
Dermatology Department, Affiliated Hospital of Jiangxi University of Chinese Medicine, Nanchang 330006, China.
Med Mycol. 2023 Apr 3;61(4). doi: 10.1093/mmy/myad034.
Trichophyton rubrum and T. mentagrophytes are the most common agents of dermatomycosis, a disease affecting millions worldwide. It has been widely recognized that secreted proteases are a key factor for host colonization. Dermatophytes have an unusually high amount of secreted protease, differentially expressed, and influenced by various conditions. This study analyzed the rule and expression of secreted deuterolysin protease of the M35 protein family in these two representative dermatophyte species. All strains secreted protease and could grow on keratin as the sole carbon and nitrogen source. Adding glucose to the keratin medium reduced the growth rate. Deuterolysin genes were most strongly expressed at acid conditions. NPIIc and NPIId expression was significantly higher than the other three deuterolysins. NPIIc had a high expression level in the two T. rubrum strains but a low expression in T. mentagrophytes strains. Both T. mentagrophytes strains had a high NPIId expression at low pH. NPIIc and NPIId deletion in T. rubrum caused a minor reduction in total protease activity, indicating the redundancy of protease in dermatophytes. It was postulated that protease gene enrichment in dermatophytes allows a sophisticated regulation of protease secretion to cope with changing conditions.
红色毛癣菌和须癣毛癣菌是皮肤癣菌病最常见的病原体，这种疾病影响着全球数百万人。人们普遍认为，分泌型蛋白酶是宿主定植的关键因素。皮肤癣菌分泌的蛋白酶数量异常多，表达存在差异，且受多种条件影响。本研究分析了这两种代表性皮肤癣菌中M35蛋白家族分泌型嗜皮菌素蛋白酶的规律和表达情况。所有菌株都能分泌蛋白酶，并且可以在以角蛋白作为唯一碳源和氮源的培养基上生长。在角蛋白培养基中添加葡萄糖会降低生长速率。嗜皮菌素基因在酸性条件下表达最强。NPIIc和NPIId的表达明显高于其他三种嗜皮菌素。NPIIc在两株红色毛癣菌中表达水平较高，但在须癣毛癣菌菌株中表达较低。两株须癣毛癣菌在低pH条件下NPIId表达均较高。红色毛癣菌中NPIIc和NPIId的缺失导致总蛋白酶活性略有降低，这表明皮肤癣菌中蛋白酶存在冗余现象。据推测，皮肤癣菌中蛋白酶基因的富集使得蛋白酶分泌能够进行精细调控，以应对不断变化的环境条件。
