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Wang Z, Cui X, Yan W, Liu N, Shang J, Yi X, Guo T, Wei X, Sun Y, Hu H, Ma W, Cui W, Chen L. Mollugin activates GLP-1R to improve cognitive dysfunction in type 2 diabetic mice. Life Sci 2023; 331:122026. [PMID: 37607641 DOI: 10.1016/j.lfs.2023.122026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 08/11/2023] [Accepted: 08/14/2023] [Indexed: 08/24/2023]
Abstract
AIMS The incidence of diabetic cognitive dysfunction is increasing year by year, and it has gradually become a research hot spot. Studies have shown that glucagon-like peptide-1 receptor (GLP-1R) agonists can improve cognitive dysfunction in diabetic patients. This study focuses on whether small molecule GLP-1R agonists from traditional Chinese medicine (TCM) can improve the diabetic cognitive dysfunction. MATERIALS AND METHODS The small molecules from TCM were screened by cell membrane chromatography (CMC) with GLP-1R-HEK293 cell membrane column. MTT assay, flow cytometry, immunofluorescence cytochemistry and other methods were used to determine the effects of mollugin on the apoptosis rate and reactive oxygen species (ROS) level of high glucose (HG)/hydrogen peroxide (H2O2) induced PC12 cells. Real-Time PCR was used to detect mRNA expression in mouse cerebral cortex. Water maze test was further used to confirm the effect of mollugin on cognitive dysfunction in T2DM mice. KEY FINDINGS Mollugin bound to GLP-1R, promoted Ca2+ influx, increased insulin secretion and cAMP content in β-TC-6 cells. Mollugin enhanced the cell viability, ameliorated apoptosis, reduced intracellular ROS levels in HG/H2O2-injured PC12 cells. Mollugin reduced the T2DM mice's escape latency, improved neuronal cell damage, decreased the expression of Pik3ca, Akt1 and Mapk1 mRNA in the cerebral cortex tissue. SIGNIFICANCE The results suggest that mollugin could improve cognitive dysfunction in T2DM mice through activating GLP-1R/cAMP/PKA signal pathway.
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Affiliation(s)
- Zhuanzhuan Wang
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Xin Cui
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Wenhui Yan
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an 710061, China
| | - Na Liu
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Jia Shang
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Xinyao Yi
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Tingli Guo
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Xiaotong Wei
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Yuzhuo Sun
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Hao Hu
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an 710061, China
| | - Weina Ma
- School of Pharmacy, Xi'an Jiaotong University, Xi'an 710061, China.
| | - Wei Cui
- Department of Endocrinology and Second Department of Geriatrics, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China; International Obesity and Metabolic Disease Research Center (IOMC), Xi'an Jiaotong University, Xi'an 710061, China.
| | - Lina Chen
- School of Pharmacy, Xi'an Jiaotong University, Xi'an 710061, China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an 710061, China.
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Park JE, Han JS. A Portulaca oleracea L. extract promotes insulin secretion via a K +ATP channel dependent pathway in INS-1 pancreatic β-cells. Nutr Res Pract 2018; 12:183-190. [PMID: 29854323 PMCID: PMC5974063 DOI: 10.4162/nrp.2018.12.3.183] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 01/08/2018] [Accepted: 02/28/2018] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND/OBJECTIVE This study was designed to investigate how a Portulaca oleracea L. extract (POE) stimulates insulin secretion in INS-1 pancreatic β-cells. MATERIALS/METHOD INS-1 pancreatic β-cells were incubated in the presence of various glucose concentrations: 1.1 or 5.6, 16.7 mM glucose. The cells were treated with insulin secretagogues or insulin secretion inhibitor for insulin secretion assay using an insulin ELISA kit. In order to quantify intracellular influx of Ca2+ caused by POE treatment, the effect of POE on intracellular Ca2+ in INS-1 pancreatic β-cells was examined using Fluo-2 AM dye. RESULTS POE at 10 to 200 µg/mL significantly increased insulin secretion dose-dependently as compared to the control. Experiments at three glucose concentrations (1.1, 5.6, and 16.7 mM) confirmed that POE significantly stimulated insulin secretion on its own as well as in a glucose-dependent manner. POE also exerted synergistic effects on insulin secretion with secretagogues, such as L-alanine, 3-isobutyl-1-methylxanthine, and especially tolbutamide, and at a depolarizing concentration of KCl. The insulin secretion caused by POE was significantly attenuated by treatment with diazoxide, an opener of the K+ATP channel (blocking insulin secretion) and by verapamil (a Ca2+ channel blocker). The insulinotropic effect of POE was not observed under Ca2+-free conditions in INS-1 pancreatic β-cells. When the cells were preincubated with a Ca2+ fluorescent dye, Fluo-2 (acetoxymethyl ester), the cells treated with POE showed changes in fluorescence in red, green, and blue tones, indicating a significant increase in intracellular Ca2+, which closely correlated with increases in the levels of insulin secretion. CONCLUSIONS These findings indicate that POE stimulates insulin secretion via a K+ATP channel-dependent pathway in INS-1 pancreatic β-cells.
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Affiliation(s)
- Jae Eun Park
- Department of Food Science and Nutrition, Pusan National University, 2, Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan 46241, Korea
| | - Ji Sook Han
- Department of Food Science and Nutrition, Pusan National University, 2, Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan 46241, Korea
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