Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, A.P. 70228, Mexico City, DF, Mexico.
Biomed Res Int. 2013;2013:758341. doi: 10.1155/2013/758341. Epub 2013 Jan 22.
Encystment is an essential process in the biological cycle of the human parasite Entamoeba histolytica. In the present study, we evaluated the participation of E. histolytica Gln6Pi in the formation of amoeba cyst-like structures by RNA interference assay. Amoeba trophozoites transfected with two Gln6Pi siRNAs reduced the expression of the enzyme in 85%, which was confirmed by western blot using an anti-Gln6Pi antibody. The E. histolytica Gln6Pi knockdown with the mix of both siRNAs resulted in the loss of its capacity to form cyst-like structures (CLSs) and develop a chitin wall under hydrogen peroxide treatment, as evidenced by absence of both resistance to detergent treatment and calcofluor staining. Thus, only 5% of treated trophozoites were converted to CLS, from which only 15% were calcofluor stained. These results represent an advance in the understanding of chitin biosynthesis in E. histolytica and provide insight into the encystment process in this parasite, which could allow for the developing of new control strategies for this parasite.
包囊形成是人类寄生虫溶组织内阿米巴生物周期中的一个必要过程。在本研究中，我们通过 RNA 干扰试验评估了 E. histolytica Gln6Pi 在形成类似囊状结构中的作用。用两种 Gln6Pi siRNA 转染的滋养体使酶的表达减少了 85%，这通过使用抗 Gln6Pi 抗体的 Western blot 得到了证实。用两种 siRNA 的混合物敲低 E. histolytica Gln6Pi 导致其失去形成类似囊状结构 (CLSs) 和在过氧化氢处理下形成几丁质壁的能力，这表现在对去污剂处理和钙荧光素染色的抗性丧失。因此，只有 5%的经处理的滋养体转化为 CLS，其中只有 15%被钙荧光素染色。这些结果代表了对 E. histolytica 几丁质生物合成的理解的进展，并为该寄生虫的包囊形成过程提供了深入了解，这可能为这种寄生虫的新的控制策略的发展提供了依据。
