title: The 29-kilodalton thiol-dependent peroxidase of Entamoeba histolytica is a factor involved in pathogenesis and survival of the parasite during oxidative stress.
abstract: The 29-kDa surface antigen (thiol-dependent peroxidase; Eh29) of Entamoeba histolytica exhibits peroxidative and protective antioxidant activities. During tissue invasion, the trophozoites are exposed to oxidative stress and need to deal with highly toxic reactive oxygen species (ROS). In this investigation, attempts have been made to understand the role of the 29-kDa peroxidase gene in parasite survival and pathogenesis. Inhibition of eh29 gene expression by antisense RNA technology has shown approximately 55% inhibition in eh29 expression, maximum ROS accumulation, and significantly lower viability in 29-kDa downregulated trophozoites during oxidative stress. The cytopathic and cytotoxic activities were also found to decrease effectively in the 29-kDa downregulated trophozoites. Size of liver abscesses was substantially lower in hamsters inoculated with 29-kDa downregulated trophozoites compared to the normal HM1:IMSS. These findings clearly suggest that the 29-kDa protein of E. histolytica has a role in both survival of trophozoites in the presence of ROS and pathogenesis of amoebiasis.
authors.affiliation: Division of Microbiology, National Institute of Cholera and Enteric Diseases, P-33, C.I.T. Road, Scheme-XM, Beliaghata, Kolkata-700 010, India.
authors.forename: Abhik
authors.initials: A
authors.lastname: Sen
authors.forename: Nabendu Sekhar
authors.initials: NS
authors.lastname: Chatterjee
authors.forename: M Ali
authors.initials: MA
authors.lastname: Akbar
authors.forename: Nilay
authors.initials: N
authors.lastname: Nandi
authors.forename: Pradeep
authors.initials: P
authors.lastname: Das
mesh_terms: D000818:Animals; D016923:Cell Death / Q000187:drug effects; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects; D004748:Entamoeba histolytica / Q000187:drug effects / Q000201:enzymology* / Q000472:pathogenicity*; D004749:Entamoebiasis; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D008101:Liver Abscess, Amebic / Q000139:chemically induced / Q000469:parasitology; D008970:Molecular Weight; D018384:Oxidative Stress / Q000187:drug effects; D010271:Parasites / Q000187:drug effects / Q000201:enzymology / Q000472:pathogenicity; D010544:Peroxidases / Q000235:genetics / Q000378:metabolism*; D010587:Phagocytosis / Q000187:drug effects; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism; D016372:RNA, Antisense / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D016019:Survival Analysis; D013752:Tetracycline / Q000494:pharmacology; D053058:Trophozoites / Q000187:drug effects / Q000502:physiology
chemical_list: D015800:Protozoan Proteins; D016372:RNA, Antisense; D017382:Reactive Oxygen Species; D010544:Peroxidases; C058652:thiol-dependent peroxidase; D013752:Tetracycline