ｍｉＲ－１９２とｍｉＲ－２１５の腸管恒常性維持における役割の解析

2015 Fiscal Year Annual Research Report

• Project/Area Number: 15J06509
• Research Institution: Osaka University
• Principal Investigator: PAREEK SIDDHIKA 大阪大学, 医学系研究科, 特別研究員(DC1)
• Project Period (FY): 2015-04-24 – 2018-03-31
• Keywords: epithelial cells / mucosal immunology / microRNA

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.

Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

We have generated miR-215-/-, and miR-192-/- 194-1-/- mice by gene targeting and soon will obtain the (triple knockout )miR-215-/- 192-/- 194-/- .
IL-17-producing CD4+ T cells were increased in the small intestine but not in the colon, of miR215-/- mice. Additionally, IFN-g-producing CD4+ T cells were marginally increased in the small intestine of miR-215-/- mice. These results suggests that miR-215 in epithelial cells might modulate Th17 and Th1 responses in the small intestine.

Strategy for Future Research Activity

We will identify the specific intestinal cell types expression miR-192 and miR-194 using laser capture microdissection.We intend to analyze the susceptibility of miR-215-/- mice compare to wild type towards C.rodentium infection.
Analyze (1) Histology, (2) Apoptotic cells, (3) Frequency of Th1, Th17, regulatory T-cells in the intestines from wild type and miR-192-/- 194-1-/-mice.
We are currently generating the miR-215-/- 192-/- 194-/- (triple knockout) mice. So far, several studies showed that expression of miR-215, miR-192, miR-194 is altered in colorectal cancer patients. Thus, we will analyze the susceptibility of triple knockout mice to AOM/DSS induced colorectal cancer.
Identify the potential target genes for miR-194 and analyze the inclusive and exclusive genes between miR-192, miR-215 and miR-194.
The validated genes targets predicted via in silico analysis will be further checked for the changes in mRNA and protein levels in the knockout models.