Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
BMC Microbiol. 2022 Apr 22;22(1):111. doi: 10.1186/s12866-022-02528-8.
Blastocystis sp., is a eukaryote of the large intestine, which is reported from almost all countries. The pathogenesis of this protist is not clear. The current study aimed to analyze the effects of Blastocystis sp., ST3 soluble total antigen (B3STA) on the microRNAs (miRNAs) involved in the gut permeability and also pro-inflammatory cytokines, occludin, and claudin-7.
Blastocystis sp., ST3 isolated from stool sample was purified, and its soluble total antigen was extracted using freeze and thawing. The Caco-2 cell line was treated with B3STA for 24 h and the expression levels of mir-16, mir-21, mir-29a, mir-223, and mir-874 were analyzed. In addition, the expression levels of il-8, il-15, occludin, and claudin-7 genes were assessed.
B3STA significantly upregulated the expression of mir-223, and mir-874, and downregulated mir-29a. The expression of mir-16 and mir-21 was not significant. In addition, the expression of il-8 and il-15 was not significant. B3STA significantly decreased the expression level of claudin-7 (P-value < 0.0001), but the expression of occludin was not significant. Our results showed significant correlation between all studied miRNAs, except mir-29a, with downregulation of claudin-7.
This is the first study investigating the effects of Blastocystis sp., ST3 isolated from symptomatic subjects on the expression levels of miRNAs involved in the gut permeability. Our results demonstrated that B3STA may change miRNA expression, which are involved in the gut barrier integrity, and downregulates claudin-7, which is known as sealing factor.
芽囊原虫是一种存在于大肠的真核生物，几乎在所有国家都有报道。该原生动物的发病机制尚不清楚。本研究旨在分析芽囊原虫 ST3 可溶性总抗原（B3STA）对参与肠道通透性的 microRNAs（miRNAs）以及促炎细胞因子、occludin 和 claudin-7 的影响。
从粪便样本中分离出芽囊原虫 ST3，经冻融法提取其可溶性总抗原。用 B3STA 处理 Caco-2 细胞系 24 小时，分析 mir-16、mir-21、mir-29a、mir-223 和 mir-874 的表达水平。此外，还评估了 il-8、il-15、occludin 和 claudin-7 基因的表达水平。
B3STA 显著上调了 mir-223 和 mir-874 的表达，下调了 mir-29a 的表达。mir-16 和 mir-21 的表达无显著差异。此外，il-8 和 il-15 的表达也不显著。B3STA 显著降低了 claudin-7 的表达水平（P 值<0.0001），但对 occludin 的表达没有显著影响。我们的结果表明，除了 mir-29a 之外，所有研究的 miRNAs 之间都存在显著相关性，与 claudin-7 的下调有关。
这是第一项研究芽囊原虫 ST3 从有症状的受试者中分离出来对参与肠道通透性的 miRNAs 表达水平的影响。我们的研究结果表明，B3STA 可能改变 miRNA 的表达，这些 miRNA 参与肠道屏障的完整性，并下调已知的密封因子 claudin-7。
