2016 Fiscal Year Annual Research Report
ｍｉＲ－１９２とｍｉＲ－２１５の腸管恒常性維持における役割の解析
| Project/Area Number |
15J06509
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| Research Institution | Osaka University |
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Principal Investigator |
PAREEK SIDDHIKA 大阪大学, 医学系研究科, 特別研究員(DC1)
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| Project Period (FY) |
2015-04-24 – 2018-03-31
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| Keywords | epithelial cells / mucosal immunology / micro RNA |
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| Outline of Annual Research Achievements |
Emerging data shows a steady increase of patients with IBD worldwide including Japan. A range of factors may contribute to the onset and manifestation of this condition. Role of specific microRNA’s and their interacting partners which might be involved in the regulation of gut homeostasis remain majorly unknown. So far, miR-192, miR-215 and miR-194 which are highly expressed miRNA’s forming gene family and cluster, have not been explored in the light of IBD. Based on the preliminary results and literature, they could potentially serve as one of the regulators of cellular processes in this disease pathogenesis.
Although the severity and disease phenotype of IBD patients is similar between Japan and the western countries. There are several unique options of IBD treatment established in Japan such as nutritional therapy, leukocyte apheresis and transplanting primary intestinal cells cultured in vitro to repair damaged colitic mucosa. However, if the underlying mechanism and involvement of these miRNA’s in the intestinal cell barrier integrity can be understood then it can offer immense therapeutic potential.
Clinical reports have documented that several chronic inflammatory diseases lead to increased risk of developing cancer. Although, differential expressions of these three miRNAs have been reported. Yet the functional role and targets interaction studies for these microRNAs have not yet been elucidated. This study might help in elucidating the role of different effector molecules that might contribute to IBD etiology and its progression in cancer.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
IL-17-producing CD4+ T cells were increased in the colons, but not the small intestines, of miR-194-/-192-/- mice suggesting that either miR-194 or miR-192-/- in epithelial cells might modulate Th17 responses in the colon.
To analyze the effect of miR-194 and miR-192 on intestinal inflammation, miR-194-/- 192-/- mice were administrated with dextran sodium sulphate (DSS), which induces inflammation in the large intestine, showed increased weight loss compared to those in DSS-treated wild-type, suggesting the protective roles of miR-192 and miR-194 in intestinal inflammation by regulating Th17 responses through maintenance of epithelial homeostasis.
RNA-seq data revealed the differential expression levels of several genes between wild-type and miRNA-deficient cells.
Among the upregulated gene population in miR-215-/- cells, we identified the miR-215 target genes predicted by miRNA-target gene prediction databases such as miRDB and microRNA.org . Among them, we focused on Cxcl12 and Adam19, because these genes were upregulated in IBD patients. Consistent with RNA-seq data, increased expression of Cxcl12 and Adam19 were observed in miR-215-/- cells by RT-qPCR.
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| Strategy for Future Research Activity |
RNA-seq data also showed several genes upregulated in miR-194-/-192-/- cells. Among these genes, several anti-microbial peptides/proteins were included. We are now validating their interactions using luciferase reporter assay.
When we identify the target genes (X-gene) of miR-215, miR-192, and miR-194 in intestinal epithelial cells, we will generate X-gene-/- miRNA-/- (double knockout) mice and analyze Th1/Th17 responses in the colon and small intestine as well as the sensitivity of DSS-induced colitis.
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Research Products
(1 results)
