title: Entamoeba histolytica: Characterization of human collagen type I and Ca2+ activated differentially expressed genes.
abstract: Earlier it was demonstrated that the Entamoeba histolytica trophozoites, when incubated with human collagen and Ca2+, expressed and released the collagenolytic activity [Munoz, M.L., Calderon, J., Rojkind, M., 1982. The collagenase of Entamoeba histolytica. Journal of Experimental Medicine 155, 42-51], a virulence factor involved in the pathogenesis of amoebiasis. In this study, attempts have been made to identify and characterize the gene(s) that are upregulated by the human collagen type I and Ca2+ interaction. A comparative evaluation of gene expression pattern of the parasite before and after treatment with human collagen type I was done using the differential display reverse transcription-PCR technique. The cDNA fragments that were overexpressed in collagen treated trophozoites compared to collagen untreated trophozoites were characterized. Northern blot hybridization and RT-PCR amplification using gene-specific primers validated the differential expression. Sequence analyses and database searches revealed homology with known virulence factor genes of E. histolytica such as amoebapore C and cysteine proteinase 5, along with stress-induced protein HSP70, and ribosomal protein L27a (known to be involved in protein synthesis). The study provides the experimental evidence that interaction of E. histolytica with human collagen type I and Ca2+ triggers the transcriptional activation of at least two important genes responsible for pathogenesis of amoebiasis.
authors.affiliation: Department of Microbiology, National Institute of Cholera and Enteric Diseases, ICMR, Kolkata, West Bengal, India.
authors.forename: Anjan
authors.initials: A
authors.lastname: Debnath
authors.forename: Md Ali
authors.initials: MA
authors.lastname: Akbar
authors.forename: Arindam
authors.initials: A
authors.lastname: Mazumder
authors.forename: Sudeep
authors.initials: S
authors.lastname: Kumar
authors.forename: Pradeep
authors.initials: P
authors.lastname: Das
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D002118:Calcium / Q000378:metabolism*; D003001:Cloning, Molecular; D024042:Collagen Type I / Q000235:genetics* / Q000378:metabolism; D018076:DNA, Complementary / Q000737:chemistry / Q000378:metabolism; D015536:Down-Regulation; D004748:Entamoeba histolytica / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D015870:Gene Expression; D006801:Humans; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012689:Sequence Homology, Nucleic Acid; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics
chemical_list: D024042:Collagen Type I; D018076:DNA, Complementary; D012333:RNA, Messenger; D037521:Virulence Factors; D002118:Calcium