miR-200c-3p regulates α4 integrin-mediated T cell adhesion and migration.

A microRNA miR-200c-3p is a regulator of epithelial-mesenchymal transition to control adhesion and migration of epithelial and mesenchymal cells. However, little is known about whether miR-200c-3p affects lymphocyte adhesion and migration mediated by integrins. Using TK-1 (a T lymphoblast cell) as a model of T cell, here we show that repressed expression of miR-200c-3p upregulated α4 integrin-mediated adhesion to and migration across mucosal addressin cell adhesion molecule-1 (MAdCAM-1). Conversely, overexpression of miR-200c-3p downregulated α4 integrin-mediated adhesion and migration. Unlike in epithelial cells, miR-200c-3p did not target talin, a conformation activator of integrin, but, targeted E26-transformation-specific sequence 1 (ETS1), a transcriptional activator of α4 integrin, in T cells. Treatment of the miR-200c-3p-low-expressing TK-1 cells that possessed elevated α4 integrin with ETS1 small interfering RNA (siRNA) resulted in the reversion of the α4 integrin expression, supporting that ETS1 is a target of miR-200c-3p. A potential proinflammatory immune-modulator retinoic acid (RA) treatment of TK-1 cells elicited a significant reduction of miR-200c-3p and simultaneously a marked increase in ETS1 and α4 integrin expression. An anti-inflammatory cytokine TGF-ß1 treatment elevated miR-200c-3p, thereby downregulating ETS1 and α4 integrin expression. These results suggest that miR-200c-3p is an important regulator of α4 integrin expression and functions and may be controlled by RA and TGF-ß1 in an opposite way. Overexpression of miR-200c-3p could be a novel therapeutic option for treatment of gut inflammation through suppressing α4 integrin-mediated T cell migration.

MicroRNA Profiles in Intestinal Epithelial Cells in a Mouse Model of Sepsis.

Sepsis is a systemic inflammatory disorder that leads to the dysfunction of multiple organs. In the intestine, the deregulation of the epithelial barrier contributes to the development of sepsis by triggering continuous exposure to harmful factors. However, sepsis-induced epigenetic changes in gene-regulation networks within intestinal epithelial cells (IECs) remain unexplored. In this study, we analyzed the expression profile of microRNAs (miRNAs) in IECs isolated from a mouse model of sepsis generated via cecal slurry injection. Among 239 miRNAs, 14 miRNAs were upregulated, and 9 miRNAs were downregulated in the IECs by sepsis. Upregulated miRNAs in IECs from septic mice, particularly miR-149-5p, miR-466q, miR-495, and miR-511-3p, were seen to exhibit complex and global effects on gene regulation networks. Interestingly, miR-511-3p has emerged as a diagnostic marker in this sepsis model due to its increase in blood in addition to IECs. As expected, mRNAs in the IECs were remarkably altered by sepsis; specifically, 2248 mRNAs were decreased, while 612 mRNAs were increased. This quantitative bias may be possibly derived, at least partly, from the direct effects of the sepsis-increased miRNAs on the comprehensive expression of mRNAs. Thus, current in silico data indicate that there are dynamic regulatory responses of miRNAs to sepsis in IECs. In addition, the miRNAs that were increased with sepsis had enriched downstream pathways including Wnt signaling, which is associated with wound healing, and FGF/FGFR signaling, which has been linked to chronic inflammation and fibrosis. These modifications in miRNA networks in IECs may lead to both pro- and anti-inflammatory effects in sepsis. The four miRNAs discovered above were shown to putatively target LOX, PTCH1, COL22A1, FOXO1, or HMGA2, via in silico analysis, which were associated with Wnt or inflammatory pathways and selected for further study. The expressions of these target genes were downregulated in sepsis IECs, possibly through posttranscriptional modifications of these miRNAs. Taken together, our study suggests that IECs display a distinctive miRNA profile which is capable of comprehensively and functionally reshaping the IEC-specific mRNA landscape in a sepsis model.

Anti-Helicobacter pylori, Anti-Inflammatory, Cytotoxic, and Antioxidant Activities of Mace Extracts from Myristica fragrans.

The aril (mace) of Myristica fragrans, known as Dok-Chan, is a spice that has long been used for treating stomach discomfort, peptic ulcer, and nausea. It is an ingredient in many remedies in Thai traditional medicine, e.g., Ya-Hom-Thep-Bha-Jit, Ya-Hom-Nao-Wa-Kot, and Ya-That-Bun-Job, which are used to treat dyspepsia and other gastrointestinal tract symptoms. The aqueous and ethanolic extracts of mace were used for all tests. Anti-H. pylori activities were determined by the disc diffusion method and agar dilution. Anti-inflammatory activity was determined by the LPS-induced nitric oxide (NO) inhibition in a RAW264.7 cell line, and cytotoxicity was determined against gastric cancer cell lines (Kato III) using the sulphorhodamine B (SRB) assay. The DPPH radical scavenging and ABTS radical cation decolorization assays were used to determine the antioxidant activities. The result found that the ethanolic extract of mace exhibited antimicrobial activity against H. pylori ATCC 43504 and six clinical strains with MIC values of 125-250 µg/ml. The aqueous extract MICs against H. pylori ATCC reference strain and six clinical strains were 500 µg/ml compared with 0.5 µg/ml for the positive control, clarithromycin. The inhibitory effect of LPS-induced NO release and cytotoxic activity of the ethanolic extract had IC50 values of 82.19 µg/ml and 26.06 µg/ml, respectively, and the EC50 values for the DPPH and ABTS antioxidant assays were 13.41 µg/ml and 12.44 µg/ml, respectively. The mace extract also had anticancer properties. In conclusion, the ethanolic mace extract had anti-H. pylori, anti-inflammatory, antioxidant, and anticancer activities. These data support further preclinical and clinical investigation to see if the mace extract could have a role in treating patients with dyspepsia, peptic ulcers, and possibly gastric cancer.