Oncotarget

Research Papers:

High glucose induces formation of tau hyperphosphorylation via Cav-1-mTOR pathway: A potential molecular mechanism for diabetes-induced cognitive dysfunction

Jing Wu, Shan-Lei Zhou, Lin-Hua Pi, Xia-Jie Shi, Ling-Ran Ma, Zi Chen, Min-Li Qu, Xin Li, Sheng-Dan Nie, Duan-Fang Liao, Jin-Jing Pei and Shan Wang _

PDF  |  HTML  |  Supplementary Files  |  How to cite  |  Order a Reprint

Oncotarget. 2017; 8:40843-40856. https://doi.org/10.18632/oncotarget.17257

Metrics: PDF 1253 views  |   HTML 1987 views  |   ?  


Abstract

Jing Wu1, Shan-Lei Zhou1, Lin-Hua Pi1, Xia-Jie Shi1, Ling-Ran Ma2, Zi Chen1, Min-Li Qu1, Xin Li2, Sheng-Dan Nie3, Duan-Fang Liao4, Jin-Jing Pei5,6,7 and Shan Wang1,2

1Department of Endocrinology, Xiang-Ya Hospital, Central South University, Changsha, Hunan, China

2Department of Pharmaceutical Engineering, College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan, China

3Institute of Clinical Medicine, People’s Hospital of Hunan Province, The First Affiliated Hospital of Hunan Normal University, Changsha, Hunan, China

4Division of Stem Cell Regulation and Application, School of Pharmacy, Hunan University of Traditional Chinese Medicine, Changsha, Hunan, China

5KI-Alzheimer’s Disease Research Center, Karolinska Institutet, Novum, Stockholm, Sweden

6Department of Neurology, Xuan Wu Hospital, Capital Medical University, Xicheng, Beijing, China

7Center of Alzheimer’s Disease, Beijing Institute for Brain Disorders, Beijing, China

Correspondence to:

Shan Wang, email: wangshancsu0717@163.com

Jing Wu, email: wujing0731@163.com

Keywords: diabetes mellitus, cognitive dysfunction, caveolin-1, tau hyperphosphorylation, mTOR

Received: February 20, 2017     Accepted: April 07, 2017     Published: April 19, 2017

ABSTRACT

The abnormally hyperphosphorylated tau is thought to be implicated in diabetes-associated cognitive deficits. The role of mammalian target of rapamycin (mTOR) / S6 kinase (S6K) signalling in the formation of tau hyperphosphorylation has been previously studied. Caveolin-1 (Cav-1), the essential structure protein of caveolae, promotes neuronal survival and growth, and inhibits glucose metabolism. In this study, we aimed to investigate the role of Cav-1 in the formation of tau hyperphosphorylation under chronic hyperglycemic condition (HGC). Diabetic rats were induced by streptozotocin (STZ). Primary hippocampal neurons with or without molecular intervention such as the transient over-expression or knock-down were subjected to HGC. The obtained experimental samples were analyzed by real time quantitative RT-PCR, Western blot, immunofluorescence or immunohistochemisty. We found: 1) that a chronic HGC directly decreases Cav-1 expression, increases tau phosphorylation and activates mTOR/S6K signalling in the brain neurons of diabetic rats, 2) that overexpression of Cav-1 attenuates tau hyperphosphorylation induced by chronic HGC in primary hippocampal neurons, whereas down-regulation of Cav-1 using Cav-1 siRNA dramatically worsens tau hyperphosphorylation via mTOR/S6K signalling pathway, and 3) that the down-regulation of Cav-1 induced by HGC is independent of mTOR signalling. Our results suggest that tau hyperphosphorylation and the sustained over-activated mTOR signalling under hyperglycemia may be due to the suppression of Cav-1. Therefore, Cav-1 is a potential therapeutic target for diabetes-induced cognitive dysfunction.


Creative Commons License All site content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 License.
PII: 17257