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Gao R, Chen Z, Wu Y, Chen R, Zheng W, Qi L, Liu X, Liu X, Liu L. SIRT3 alleviates mitochondrial dysfunction induced by recurrent low glucose and improves the supportive function of astrocytes to neurons. Free Radic Biol Med 2022; 193:405-420. [PMID: 36306990 DOI: 10.1016/j.freeradbiomed.2022.10.313] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Revised: 09/22/2022] [Accepted: 10/20/2022] [Indexed: 11/06/2022]
Abstract
Hypoglycemia is an independent risk factor of cognitive impairment in patients with diabetes. Our previous study indicated that dysfunction of astrocytic mitochondria induced by recurrent low glucose (RLG) may account for hypoglycemia-associated neuronal injury and cognitive decline. Sirtuin 3 (SIRT3) is a key deacetylase for mitochondrial proteins and has recently been demonstrated to be an important regulator of mitochondrial function. However, whether mitochondrial dysfunction due to hypoglycemia is associated with astrocytic SIRT3 remains unclear, and few studies have focused on the impact of astrocytic SIRT3 on neuronal survival. In the present work, primary mouse cortical astrocytes cultured in normal glucose (5.5 mM) and high glucose (16.5 mM) were treated with five rounds of RLG (0.1 mM). The results showed that RLG suppressed SIRT3 expression in a glucose-dependent manner. High-glucose culture considerably increased the vulnerability of SIRT3 to RLG, leading to disrupted mitochondrial morphology in astrocytes. Overexpression of SIRT3 markedly improved astrocytic mitochondrial function and reduced RLG-induced oxidative stress. Moreover, SIRT3 suppressed a shift towards a neuroinflammatory A1-like reactive phenotype of astrocytes in response to RLG with reduced IL-1β, IL-6, and TNFα levels. Furthermore, it elevated brain-derived neurotrophic factor (BDNF) levels and promoted neurite growth by activating BDNF/TrkB signaling in the co-cultured neurons. The present study reveals the probable crosstalk between neurons and astrocytes after hypoglycemic exposure and provides a potential target in treating hypoglycemia-associated neuronal injury.
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Affiliation(s)
- Ruonan Gao
- Department of Endocrinology, Fujian Medical University Union Hospital, Fuzhou, 350001, China
| | - Zhou Chen
- Department of Clinical Pharmacy and Pharmacy Administration, School of Pharmacy, Fujian Medical University, Fuzhou, 350122, China; Fujian Key Laboratory of Natural Medicine Pharmacology, Fujian Medical University, Fuzhou, 350122, China
| | - Yubin Wu
- Department of Endocrinology, Fujian Medical University Union Hospital, Fuzhou, 350001, China
| | - Ruiyu Chen
- Department of Clinical Pharmacy and Pharmacy Administration, School of Pharmacy, Fujian Medical University, Fuzhou, 350122, China
| | - Wenrong Zheng
- Department of Clinical Pharmacy and Pharmacy Administration, School of Pharmacy, Fujian Medical University, Fuzhou, 350122, China
| | - Liqin Qi
- Department of Endocrinology, Fujian Medical University Union Hospital, Fuzhou, 350001, China
| | - Xiaoying Liu
- Department of Endocrinology, Fujian Medical University Union Hospital, Fuzhou, 350001, China
| | - Xiaohong Liu
- Department of Endocrinology, Fujian Medical University Union Hospital, Fuzhou, 350001, China
| | - Libin Liu
- Department of Endocrinology, Fujian Medical University Union Hospital, Fuzhou, 350001, China.
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