1. miR-495 promotes intestinal epithelial cell apoptosis through downregulation of Sphingosine-1-phosphate.
- Author
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Li R, Cairns C, Yu TX, Jaladanki R, Dodson CM, Chung HK, Xiao L, Wang JY, and Turner DJ
- Subjects
- Animals, Mice, Cell Proliferation, Down-Regulation, Epithelial Cells metabolism, Humans, Male, Mice, Inbred C57BL, Mice, Transgenic, MicroRNAs metabolism, MicroRNAs genetics, Lysophospholipids metabolism, Sphingosine analogs & derivatives, Sphingosine metabolism, Apoptosis, Phosphotransferases (Alcohol Group Acceptor) metabolism, Phosphotransferases (Alcohol Group Acceptor) genetics, Intestinal Mucosa metabolism
- Abstract
Many pathological conditions lead to defects in intestinal epithelial integrity and loss of barrier function; Sphingosine-1-phosphate (S1P) has been shown to augment intestinal barrier integrity, though the exact mechanisms are not completely understood. We have previously shown that overexpression of Sphingosine Kinase 1 (SphK1), the rate limiting enzyme for S1P synthesis, significantly increased S1P production and cell proliferation. Here we show that microRNA 495 (miR-495) upregulation led to decreased levels of SphK1 resultant from a direct effect at the SphK1 mRNA. Increasing expression of miR-495 in intestinal epithelial cells resulted in decreased proliferation and increased susceptibility to apoptosis. Transgenic expression of miR-495 inhibited mucosal growth, as well as decreased proliferation in the crypts. The intestinal villi also expressed decreased levels of barrier proteins and exaggerated damage upon exposure to cecal ligation-puncture. These results implicate miR-495 as a critical negative regulator of intestinal epithelial protection and proliferation through direct regulation of SphK1, the rate limiting enzyme critical for production of S1P., (© 2024 The Author(s). Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)
- Published
- 2024
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