{"title":"Clostridium perfringens epsilon-toxin requires acid sphingomyelinase for cellular entry","authors":"Yoshihiko Sakaguchi, Keiko Kobayashi, Masaya Takehara, Masahiro Nagahama","doi":"10.1016/j.anaerobe.2023.102753","DOIUrl":null,"url":null,"abstract":"<div><h3>Objectives</h3><p><span><em>Clostridium perfringens</em></span><span><span><span> epsilon-toxin is considered to be a crucial agent in enterotoxemia<span> in domestic animals. Epsilon-toxin enters host cells via endocytosis and results in the formation of late endosome/lysosome-derived </span></span>vacuoles<span>. In the present study, we found that acid sphingomyelinase promotes the </span></span>internalization of epsilon-toxin in MDCK cells.</span></p></div><div><h3>Methods</h3><p>We measured the extracellular release of acid sphingomyelinase (ASMase) by epsilon-toxin. We examined the role of ASMase in epsilon-toxin-induced cytotoxicity using selective inhibitors and knockdown of ASMase. Production of ceramide<span> after toxin treatment<span> was determined by immunofluorescence technique.</span></span></p></div><div><h3>Results</h3><p><span>Blocking agents of ASMase and exocytosis of lysosomes inhibited this epsilon-toxin-induced vacuole formation. Lysosomal ASMase was liberated to extracellular space during treatment of the cells with epsilon-toxin in the presence of Ca</span><sup>2+</sup><span><span><span>. RNAi-mediated attenuation of ASMase blocked epsilon-toxin-induced vacuolation. Moreover, incubation of MDCK cells with epsilon-toxin led to production of ceramide. The ceramide colocalized with lipid raft-binding cholera toxin subunit B (CTB) in the cell membrane, indicating that conversion of </span>lipid raft associated </span>sphingomyelin to ceramide by ASMase facilitates lesion of MDCK cells and internalization of epsilon-toxin.</span></p></div><div><h3>Conclusions</h3><p>Based on the present results, ASMase is required for efficient internalization of epsilon-toxin.</p></div>","PeriodicalId":8050,"journal":{"name":"Anaerobe","volume":null,"pages":null},"PeriodicalIF":2.5000,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Anaerobe","FirstCategoryId":"99","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1075996423000628","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Objectives
Clostridium perfringens epsilon-toxin is considered to be a crucial agent in enterotoxemia in domestic animals. Epsilon-toxin enters host cells via endocytosis and results in the formation of late endosome/lysosome-derived vacuoles. In the present study, we found that acid sphingomyelinase promotes the internalization of epsilon-toxin in MDCK cells.
Methods
We measured the extracellular release of acid sphingomyelinase (ASMase) by epsilon-toxin. We examined the role of ASMase in epsilon-toxin-induced cytotoxicity using selective inhibitors and knockdown of ASMase. Production of ceramide after toxin treatment was determined by immunofluorescence technique.
Results
Blocking agents of ASMase and exocytosis of lysosomes inhibited this epsilon-toxin-induced vacuole formation. Lysosomal ASMase was liberated to extracellular space during treatment of the cells with epsilon-toxin in the presence of Ca2+. RNAi-mediated attenuation of ASMase blocked epsilon-toxin-induced vacuolation. Moreover, incubation of MDCK cells with epsilon-toxin led to production of ceramide. The ceramide colocalized with lipid raft-binding cholera toxin subunit B (CTB) in the cell membrane, indicating that conversion of lipid raft associated sphingomyelin to ceramide by ASMase facilitates lesion of MDCK cells and internalization of epsilon-toxin.
Conclusions
Based on the present results, ASMase is required for efficient internalization of epsilon-toxin.
期刊介绍:
Anaerobe is essential reading for those who wish to remain at the forefront of discoveries relating to life processes of strictly anaerobes. The journal is multi-disciplinary, and provides a unique forum for those investigating anaerobic organisms that cause infections in humans and animals, as well as anaerobes that play roles in microbiomes or environmental processes.
Anaerobe publishes reviews, mini reviews, original research articles, notes and case reports. Relevant topics fall into the broad categories of anaerobes in human and animal diseases, anaerobes in the microbiome, anaerobes in the environment, diagnosis of anaerobes in clinical microbiology laboratories, molecular biology, genetics, pathogenesis, toxins and antibiotic susceptibility of anaerobic bacteria.