Department of Microbiology and Molecular Genetics, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA.
G3 (Bethesda). 2021 Feb 9;11(2). doi: 10.1093/g3journal/jkaa055.
The nematode Caenorhabditis elegans is commonly used as a model organism in studies of the host immune response. The worm encodes twelve peroxidase-cyclooxygenase superfamily members, making it an attractive model in which to study the functions of heme peroxidases. In previous work, loss of one of these peroxidases, SKPO-1 (ShkT-containing peroxidase), rendered C. elegans more sensitive to the human, Gram-positive pathogen Enterococcus faecalis. SKPO-1 was localized to the hypodermis of the animals where it also affected cuticle development as indicated by a morphological phenotype called "dumpy." In this work, a better understanding of how loss of skpo-1 impacts both sensitivity to pathogen as well as cuticle development was sought by subjecting a deletion mutant of skpo-1 to transcriptome analysis using RNA sequencing following exposure to control (Escherichia coli) and pathogenic (E. faecalis) feeding conditions. Loss of skpo-1 caused a general upregulation of genes encoding collagens and other proteins related to cuticle development. On E. faecalis, these animals also failed to upregulate guanylyl cyclases that are often involved in environmental sensing. Hoechst straining revealed increased permeability of the cuticle and atomic force microscopy exposed the misalignment of the cuticular annuli and furrows. These findings provide a basis for better understanding of the morphological as well as the pathogen sensitivity phenotypes associated with loss of SKPO-1 function.
秀丽隐杆线虫通常被用作宿主免疫反应研究的模式生物。该虫编码 12 种过氧化物酶-环加氧酶超家族成员，使其成为研究血红素过氧化物酶功能的理想模型。在之前的工作中，缺失其中一种过氧化物酶 SKPO-1（ShkT 包含过氧化物酶）使秀丽隐杆线虫对人类革兰氏阳性病原体粪肠球菌更敏感。SKPO-1 定位于动物的皮下组织，在那里它还影响表皮发育，表现为一种称为“矮胖”的形态表型。在这项工作中，通过对 skpo-1 的缺失突变体进行转录组分析，使用 RNA 测序在暴露于对照（大肠杆菌）和致病性（粪肠球菌）喂养条件下，更好地了解 skpo-1 的缺失如何影响病原体敏感性和表皮发育。skpo-1 的缺失导致编码胶原蛋白和其他与表皮发育相关的蛋白质的基因普遍上调。在粪肠球菌上，这些动物也未能上调通常参与环境感应的鸟苷酸环化酶。Hoechst 染色显示表皮通透性增加，原子力显微镜显示表皮环和沟的排列紊乱。这些发现为更好地理解与 SKPO-1 功能丧失相关的形态和病原体敏感性表型提供了基础。
