Modulation of microRNAs and claudin-7 in Caco-2 cell line treated with Blastocystis sp., subtype 3 soluble total antigen

Abstract

Background 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. Methods 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. Results 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. Conclusions 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.

Profiling of the fecal microbiota and circulating microRNA-16 in IBS subjects with Blastocystis infection : a case–control study

“…The expression level of mir-16 was evaluated using stem-loop reverse transcriptase and real-time PCR using primers and protocols, which were previously explained [ 19 ]. For this purpose, RNA was extracted using Trizol extraction protocol (BioMix) from serum samples, which were collected from enrolled participants.…”

“…The concentration of extracted RNAs was determined by NanoDrop (NanoDrop Technologies, USA) apparatus, and RNA adjustment was performed before complementary DNA (cDNA) synthesis. cDNA was constructed for mir-16 and U6, as housekeeping gene, using cDNA synthesis kit (Pars Tous, Mashhad, Iran), as explained previously [ 19 ].…”

“…There is a little data about the correlation of Blastocystis and the gut barrier functions. Recently, the role of Blastocystis on the regulation of micro RNAs (miRNAs/mir) and tight junction (TJ) proteins of the gut has been suggested [ 19 ]. It was shown that total antigen derived from Blastocystis subtype 3 induces the expression of mir-223 and mir-874, which both are associated with gut barrier dysfunctions [ 19 ].…”

“…Recently, the role of Blastocystis on the regulation of micro RNAs (miRNAs/mir) and tight junction (TJ) proteins of the gut has been suggested [ 19 ]. It was shown that total antigen derived from Blastocystis subtype 3 induces the expression of mir-223 and mir-874, which both are associated with gut barrier dysfunctions [ 19 ]. MiRNAs are short non-coding, single-stranded RNAs that found in all eukaryotic and human cells, with an average length of 19–25 nucleotides, which control protein-coding gene expression at the post-transcriptional stage [ 20 ].…”

Gut Microbiota Shifting in Irritable Bowel Syndrome: The Mysterious Role of Blastocystis sp.

“…Moreover, a most recently published study suggested that Blastocystis sp. ST3 can modulate the expression levels of microRNAs involved in the gut barrier integrity, and claudin-7 ( 54 ). Notably, claudin-7 is categorized among pre-sealing tight junction proteins and plays a critical role in reducing the permeability of the gut ( 55 ).…”