Clinical Interventions in Aging (Jun 2021)

MALAT1 Regulated mTOR-Mediated Tau Hyperphosphorylation by Acting as a ceRNA of miR144 in Hippocampus Cells Exposed to High Glucose

  • Lu C,
  • Zhao Y,
  • Cao Y,
  • Liu L,
  • Wu S,
  • Li D,
  • Liu S,
  • Xiao S,
  • Wei Y,
  • Li X

Journal volume & issue
Vol. Volume 16
pp. 1185 – 1191

Abstract

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Chong Lu,1,* Yikui Zhao,2,* Yan Cao,3,* Li Liu,1 Shanshan Wu,1 Dongbin Li,1 Shuang Liu,1 Shuyuan Xiao,1 Yafen Wei,1 Xinyu Li3 1Department of Neurology, Heilongjiang Provincial Hospital, Harbin, People’s Republic of China; 2HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin, People’s Republic of China; 3Department of Endocrinology, First Affiliated Hospital of Harbin Medical University, Harbin, People’s Republic of China*These authors contributed equally to this workCorrespondence: Xinyu Li; Yafen Wei Tel +86-13796658016; Tel +86-13796658016Email [email protected]; [email protected]: High glucose (HG)-induced activation of mTOR promotes tau phosphorylation and leads to diabetes-associated dementia. This study aimed to explore the role of metastasis associated in lung adenocarcinoma transcript 1 (MALAT1) in HG-induced neuronal cell injury.Methods: Hippocampus cells were isolated from C57BL/6J mice. After 6 days of culture, the cells were incubated with 5.5 mM glucose in normal medium or 75 mM glucose for 4 days. Cells were transfected with miR-144 mimic, miR-144 inhibitor, siRNA for MALAT1 or corresponding controls. Gene expression was detected by PCR and Western blot analysis.Results: HG increased the levels of MALAT1 and p-tau in hippocampal cells. Knockdown of MALAT1 partially reversed the effects of HG on mTOR activity and p-tau protein levels. MALAT1 functioned as competing endogenous RNA (ceRNA) for miR-144, and pre-treatment with MALAT1 siRNA decreased mTOR activity and p-tau protein level in HG-treated hippocampal cells, which was significantly attenuated by miR-144 mimics. Moreover, miR-144 negatively regulated the expression of mTOR and knockdown of MALAT1 suppressed mTOR, while overexpression of mTOR abrogated protective effects of MALAT1 knockdown in HG-treated hippocampal cells.Conclusion: MALAT1 knockdown prevented HG-induced mTOR activation and inhibited tau phosphorylation. MALAT1 may be a therapy target for diabetes associated dementia.Keywords: diabetes mellitus, tau, MALAT1, mTOR, miR-144

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