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Parasitology Research

, Volume 112, Issue 3, pp 1221–1227 | Cite as

Silencing of xylose isomerase and cellulose synthase by siRNA inhibits encystation in Acanthamoeba castellanii

  • Yousuf Aqeel
  • Ruqaiyyah Siddiqui
  • Naveed Ahmed KhanEmail author
Original Paper

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.

Keywords

Xylose Cyst Wall Basic Local Alignment Search Tool Xylose Isomerase Acanthamoeba Castellanii 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgments

This work was partially supported by grants from the Aga Khan University.

References

  1. Achar SB, Weisman RA (1980) Adenylate cyclase activity during growth and encystment of Acanthamoeba castellanii. Biochim Biophys Acta 629:225–234PubMedCrossRefGoogle Scholar
  2. Anderson IJ, Watkins RF, Samuelson J, Spencer DF, Majoros WH, Gray MW, Loftus BJ (2005) Gene discovery in the Acanthamoeba castellanii genome. Protist 156:203–214PubMedCrossRefGoogle Scholar
  3. Ankel H, Feingold DS (1965) Biosynthesis of uridine diphosphate d-xylose. 1. Uridine diphosphate glucuronate carboxy-lyase of wheat germ. Biochem 4:2468–2475CrossRefGoogle Scholar
  4. Dudley R, Alsam S, Khan NA (2008) The role of proteases in the differentiation of Acanthamoeba castellanii. FEMS Microbiol Lett 286:9–15PubMedCrossRefGoogle Scholar
  5. Dudley R, Jarroll EL, Khan NA (2009) Carbohydrate analysis of Acanthamoeba castellanii. Exp Parasitol 122:338–343PubMedCrossRefGoogle Scholar
  6. Dudley R, Matin A, Alsam S, Sissons J, Maghsood AH, Khan NA (2005) Acanthamoeba isolates belonging to T1, T2, T3, T4 but not T7 encyst in response to increased osmolarity and cysts do not bind to human corneal epithelial cells. Acta Trop 95:100–108PubMedCrossRefGoogle Scholar
  7. Henrick K, Collyer CA, Blow DM (1989) Structures of d-xylose isomerase from Arthrobacter strain B3728 containing the inhibitors xylitol and d-sorbitol at 2.5 A and 2.3 A resolution, respectively. J Mol Biol 208:129–157PubMedCrossRefGoogle Scholar
  8. John KV, Schutzbach JS, Ankel H (1977) Separation and allosteric properties of two forms of UDP-glucuronate carboxy-lyase. J Biol Chem 252:8013–8017PubMedGoogle Scholar
  9. Lee CY, Bagdasarian M, Meng MH, Zeikus JG (1990) Catalytic mechanism of xylose (glucose) isomerase from Clostridium thermosulfurogenes: characterization of the structural gene and function of active site histidine. J Biol Chem 265:19082–19090PubMedGoogle Scholar
  10. Lorenzo-Morales J, Kliescikova J, Martinez-Carretero E, De Pablos LM, Profotova B, Nohynkova E, Osuna A, Valladares B (2008) Glycogen phosphorylase in Acanthamoeba spp.: determining the role of the enzyme during the encystment process using RNA interference. Eukaryot Cell 7:509–517PubMedCrossRefGoogle Scholar
  11. Martin SM, Byers TJ (1976) Acid hydrolase activity during growth and encystment in Acanthamoeba castellanii. J Protozool 23:608–613PubMedGoogle Scholar
  12. Matin A, Stins M, Kim KS, Khan NA (2006) Balamuthia mandrillaris exhibits metalloprotease activities. FEMS Immunol Med Microbiol 47:83–91PubMedCrossRefGoogle Scholar
  13. Mehdi H, Garg NK (1987) Changes in the lipid composition and activities of isocitrate dehydrogenase and isocitrate lyase during encystation of Acanthamoeba culbertsoni strain A-1. Trans R Soc Trop Med Hyg 81:633–636PubMedCrossRefGoogle Scholar
  14. Moon EK, Chung DI, Hong Y, Kong HH (2011) Expression levels of encystation mediating factors in fresh strain of Acanthamoeba castellanii cyst ESTs. Exp Parasitol 127:811–816PubMedCrossRefGoogle Scholar
  15. Moon EK, Chung DI, Hong YC, Kong HH (2007) Differentially expressed genes of Acanthamoeba castellanii during encystation. Kor J Parasitol 45:283–285CrossRefGoogle Scholar
  16. Moon EK, Chung DI, Hong YC, Ahn TI, Kong HH (2008) Acanthamoeba castellanii: gene profile of encystation by ESTs analysis and KOG assignment. Exp Parasitol 119:111–116PubMedCrossRefGoogle Scholar
  17. Neff RJ, Neff RH (1969) The biochemistry of amoebic encystment. Symp Soc Exp Biol 23:51–81PubMedGoogle Scholar
  18. Potter JL, Weisman RA (1972) Correlation of cellulose synthesis in vivo and in vitro during the encystment of Acanthamoeba. Dev Biol 28:472–477PubMedCrossRefGoogle Scholar
  19. Potter JL, Weisman RA (1976) Cellulose synthesis by extracts of Acanthamoeba castellanii during encystment. Stimulation of the incorporation of radioactivity from UDP-(14C) glucose into alkali-soluble and insoluble beta-glucans by glucose 6-phosphate and related compounds. Biochim Biophys Acta 428:240–252PubMedCrossRefGoogle Scholar
  20. Siddiqui R, Khan NA (2012) Biology and pathogenesis of Acanthamoeba. Parasit Vectors 5:6PubMedCrossRefGoogle Scholar
  21. Siddiqui R, Khan NA, Jarroll EL (2009) The cyst wall carbohydrate composition of Balamuthia mandrillaris. Parasitol Res 104:1439–1443PubMedCrossRefGoogle Scholar
  22. Sissons J, Kim KS, Stins M, Jayasekera S, Alsam S, Khan NA (2005) Acanthamoeba castellanii induces host cell death via a phosphatidylinositol 3-kinase-dependent mechanism. Infect Immun 73:2704–2708PubMedCrossRefGoogle Scholar
  23. Strominger JL, Mapson LW (1957) Uridine diphosphoglucose dehydrogenase of pea seedlings. Biochem J 66:567–572PubMedGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • Yousuf Aqeel
    • 1
  • Ruqaiyyah Siddiqui
    • 1
  • Naveed Ahmed Khan
    • 1
    Email author
  1. 1.Department of Biological and Biomedical SciencesAga Khan UniversityKarachiPakistan

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