Leucine increases mucin 2 and occludin production in LS174T cells partially via PI3K-Akt-mTOR pathway

• Main Authors: Xiangbing Mao, Haiyan Hu, Jun Tang, Daiwen Chen, Bing Yu
• Format: Article
• Language: English
• Published: KeAi Communications Co., Ltd. 2016-09-01
• Series: Animal Nutrition
• Subjects: Mucin 2; Occludin; Leucine; LS174T cells; PI3K-Akt-mTOR
• Online Access: http://www.sciencedirect.com/science/article/pii/S2405654516300476

Mucin 2 and occludin play a crucial role in preserving the intestinal mucosal integrity. However, the role for leucine mediating intestinal mucin 2 and occludin expression has little been investigated. The current study was conducted to test the hypothesis that leucine treatment could increase mucin 2 and occludin levels in LS174T cells. The LS174T cells were incubated in the Dulbecco's Modified Eagle Medium (DMEM) supplementing 0, 0.5 and 5 mmol/L L-leucine for the various durations. Two hours after the leucine treatment, the inhibitor of mammalian target of rapamycin (mTOR) and protein kinase B (Akt) phosphorylation in LS174T cells were significantly increased (P < 0.05), and the mucin 2 and occludin levels were also significantly enhanced (P < 0.05). However, the pretreatment of 10 nmol/L rapamycin, which was an mTOR inhibitor, or 1 μmol/L wortmanin, which was an inhibitor of phosphatidylinositol 3-kinase (PI3K), completely inhibited leucine-induced mTOR or Akt phosphorylation (P < 0.05), and significantly reduced leucine-stimulated mucin 2 and occludin levels (P < 0.05). These results suggest that leucine treatment promotes the mucin 2 and occludin levels in LS174T cells partially through the PI3K-Akt-mTOR signaling pathway.