title: Statin pleiotropy prevents rho kinase-mediated intestinal epithelial barrier compromise induced by Blastocystis cysteine proteases.
abstract: Blastocystis is an enteric parasite that causes acute and chronic intestinal infections, often non-responsive to conventional antibiotics. The effects of Blastocystis infections on human epithelial permeability are not known, and molecular mechanisms of Blastocystis-induced intestinal pathology remain unclear. This study was conducted to determine whether Blastocystis species alters human intestinal epithelial permeability, to assess whether these abnormalities are rho kinase (ROCK)-dependent, and to investigate the therapeutic potential of the HMG-CoA reductase inhibitor Simvastatin in altered intestinal epithelial barrier function. The effect of metronidazole resistant (Mz(r)) Blastocystis isolated from a symptomatic patient on human colonic epithelial monolayers (Caco-2) was assessed. Modulation of enterocyte myosin light chain phosphorylation, transepithelial fluorescein isothiocyanate-dextran fluxes, transepithelial resistance, cytoskeletal F-actin and tight junctional zonula occludens-1 (ZO-1) by parasite cysteine proteases were measured in the presence or absence of HMG-CoA reductase and ROCK inhibition. Blastocystis significantly decreased transepithelial resistance, increased epithelial permeability, phosphorylated myosin light chain and reorganized epithelial actin cytoskeleton and ZO-1. These alterations were abolished by inhibition of enterocyte ROCK, HMG-CoA reductase and parasite cysteine protease. Our findings suggest that cysteine proteases of Mz(r) Blastocystis induce ROCK-dependent disruption of intestinal epithelial barrier function and correlates with reorganization of cytoskeletal F-actin and tight junctional ZO-1. Simvastatin prevented parasite-induced barrier-compromise, suggesting a therapeutic potential of statins in intestinal infections.
authors.affiliation: Singapore Immunology Network, Biomedical Sciences Institutes, Agency for Science, Technology and Research, 8A Biomedical Grove, Immunos, Singapore 138648, Singapore.
authors.forename: Haris
authors.initials: H
authors.lastname: Mirza
authors.forename: Zhaona
authors.initials: Z
authors.lastname: Wu
authors.forename: Joshua D W
authors.initials: JD
authors.lastname: Teo
authors.forename: Kevin S W
authors.initials: KS
authors.lastname: Tan
mesh_terms: D016844:Blastocystis / Q000201:enzymology* / Q000276:immunology* / Q000472:pathogenicity; D018938:Caco-2 Cells; D057056:Cysteine Proteases / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism; D006801:Humans; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000469:parasitology*; D010539:Permeability; D019821:Simvastatin / Q000494:pharmacology*; D037521:Virulence Factors / Q000378:metabolism; D062826:Zonula Occludens-1 Protein / Q000378:metabolism; D054460:rho-Associated Kinases / Q000378:metabolism*
chemical_list: D037521:Virulence Factors; D062826:Zonula Occludens-1 Protein; D019821:Simvastatin; D054460:rho-Associated Kinases; D057056:Cysteine Proteases