Login / Signup

miR-495 promotes intestinal epithelial cell apoptosis through downregulation of Sphingosine-1-phosphate.

Ruiyun LiCassandra A CairnsTing-Xi YuRao JaladankiClaire M DodsonHee Kyoung ChungLan XiaoJian-Ying WangDouglas J Turner
Published in: Physiological reports (2024)
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.
Keyphrases
  • cell proliferation
  • long non coding rna
  • poor prognosis
  • cell cycle
  • signaling pathway
  • long noncoding rna
  • pi k akt
  • oxidative stress
  • cell cycle arrest
  • tyrosine kinase
  • density functional theory
  • molecular dynamics