title: Silencing of xylose isomerase and cellulose synthase by siRNA inhibits encystation in Acanthamoeba castellanii.
abstract: A key challenge in the successful treatment of Acanthamoeba infections is its ability to transform into a dormant cyst form that is resistant to physiological conditions and pharmacological therapies, resulting in recurrent infections. The carbohydrate linkage analysis of cyst walls of Acanthamoeba castellanii showed variously linked sugar residues, including xylofuranose/xylopyranose, glucopyranose, mannopyranose, and galactopyranose. Here, it is shown that exogenous xylose significantly reduced A. castellanii differentiation in encystation assays (P < 0.05 using paired t test, one-tailed distribution). Using small interfering RNA (siRNA) probes against xylose isomerase and cellulose synthase, as well as specific inhibitors, the findings revealed that xylose isomerase and cellulose synthase activities are crucial in the differentiation of A. castellanii. Inhibition of both enzymes using siRNA against xylose isomerase and cellulose synthase but not scrambled siRNA attenuated A. castellanii metamorphosis, as demonstrated by the arrest of encystation of A. castellanii. Neither inhibitor nor siRNA probes had any effect on the viability and extracellular proteolytic activities of A. castellanii.
authors.affiliation: Department of Biological and Biomedical Sciences, Aga Khan University, Stadium Road, Karachi, Pakistan.
authors.forename: Yousuf
authors.initials: Y
authors.lastname: Aqeel
authors.forename: Ruqaiyyah
authors.initials: R
authors.lastname: Siddiqui
authors.forename: Naveed Ahmed
authors.initials: NA
authors.lastname: Khan
mesh_terms: D048248:Acanthamoeba castellanii / Q000201:enzymology* / Q000254:growth & development*; D019747:Aldose-Ketose Isomerases / Q000037:antagonists & inhibitors* / Q000235:genetics; D020868:Gene Silencing; D005964:Glucosyltransferases / Q000037:antagonists & inhibitors* / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism*; D033761:Spores, Protozoan / Q000201:enzymology* / Q000254:growth & development*
chemical_list: D034741:RNA, Small Interfering; D005964:Glucosyltransferases; C478648:cellulose synthase; D019747:Aldose-Ketose Isomerases; C023298:xylose isomerase