Plant MIR167e-5p Inhibits Enterocyte Proliferation by Targeting β-Catenin

Abstract

MicroRNAs (miRNAs) are important negative regulators of genes involved in physiological and pathological processes in plants and animals. It is worth exploring whether plant miRNAs play a cross-kingdom regulatory role in animals. Herein, we found that plant MIR167e-5p regulates the proliferation of enterocytes in vitro. A porcine jejunum epithelial cell line (IPEC-J2) and a human colon carcinoma cell line (Caco-2) were treated with 0, 10, 20, and 40 pmol of synthetic 2′-O-methylated plant MIR167e-5p, followed by a treatment with 20 pmol of MIR167e-5p for 0, 24, 48, and 72 h. The cells were counted, and IPEC-J2 cell viability was determined by the MTT and EdU assays at different time points. The results showed that MIR167e-5p significantly inhibited the proliferation of enterocytes in a dose- and time-dependent manner. Bioinformatics prediction and a luciferase reporter assay indicated that MIR167e-5p targets β-catenin. In IPEC-J2 and Caco-2 cells, MIR167e-5p suppressed proliferation by downregulating β-catenin mRNA and protein levels. MIR167e-5p relieved this inhibition. Similar results were achieved for the β-catenin downstream target gene c-Myc and the proliferation-associated gene PCNA. This research demonstrates that plant MIR167e-5p can inhibit enterocyte proliferation by targeting the β-catenin pathway. More importantly, plant miRNAs may be a new class of bioactive molecules for epigenetic regulation in humans and animals.

Plant miRNAs Reduce Cancer Cell Proliferation by Targeting MALAT1 and NEAT1: A Beneficial Cross-Kingdom Interaction

“…Recently, numerous scientific studies have demonstrated the presence of plant miRNAs in body fluids: serum, saliva, urine, and in gastric and colon mucosa (Minutolo et al, 2018;Li et al, 2019;Link et al, 2019) and demonstrated that these circulating miRNAs might have a significant involvement in miRNA-mediated gene expression regulation. On the other hand, it has long been known that ingested RNA from food sources in nematodes and insects can control their gene expression (Whangbo and Hunter, 2008).…”

“…In exosome-like nut nanovesicles, plant miR159a and miR156c reduce the level of tumor necrosis factor (TNF) receptor superfamily member 1a (Tnfrsf1a) transcript leading to a decrease in TNF-α signaling pathway and inflammatory markers (Aquilano et al, 2019). Moreover, it was recently reported that MIR167e-5p represses intestinal cell proliferation by targeting β-catenin (Li et al, 2019). More recently, Minutolo et al demonstrated that the natural oeu-sRNAs decrease the protein expression of hsa-miR34a mRNA targets, reducing proliferation and increasing apoptosis in different tumor cells.…”

“…Altogether these features might allow a cross-kingdom functional interaction. This hypothesis is supported by a growing number of papers published in the last decade (Minutolo et al, 2018;Li et al, 2018aLi et al, , 2019Link et al, 2019).…”

Potential Mechanisms Linking Food-Derived MicroRNAs, Gut Microbiota and Intestinal Barrier Functions in the Context of Nutrition and Human Health

“…Interestingly, the direct impact of plant xenomiRs on intestinal epithelial cell gene expression modulation has not been deeply addressed yet. Nevertheless, some studies have proposed that specific xenomiRs could have an impact on intestinal transporter expression or enterocyte proliferation ( 153 , 165 , 166 ), which suggests a potential role for xenomiRs in the modulation of the function of intestinal cells, including molecule absorption or intestinal barrier integrity and functionality. In this context, Fujita et al ( 165 ) reported that Caco-2 cells treated with apple exosome-like nanovesicles displayed changes in mRNA expression of several intestinal transporters including the organic-anion-transporting polypeptide (OATP2B1), whose mRNA and protein expression, along with its activity, decreased, probably by a miRNA-mediated mechanism, which potentially could modulate absorption of orally administered compounds in vivo ( 165 ).…”

“…In this context, Fujita et al ( 165 ) reported that Caco-2 cells treated with apple exosome-like nanovesicles displayed changes in mRNA expression of several intestinal transporters including the organic-anion-transporting polypeptide (OATP2B1), whose mRNA and protein expression, along with its activity, decreased, probably by a miRNA-mediated mechanism, which potentially could modulate absorption of orally administered compounds in vivo ( 165 ). It has also been reported that synthetic plant miR-167e-5p regulated the expression of Wnt/β-catenin signaling pathway key molecules, such as β-catenin and c-Myc, negatively impacting on enterocyte proliferation in vitro ( 166 ). Similar results were also observed for plant miR-156 treatment in vitro and in vivo .…”