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.
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.
Life Sci. 2023 Oct 15;331:122026. doi: 10.1016/j.lfs.2023.122026. Epub 2023 Aug 21.
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.
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 (HO) 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.
Mollugin bound to GLP-1R, promoted Ca 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/HO-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.
The results suggest that mollugin could improve cognitive dysfunction in T2DM mice through activating GLP-1R/cAMP/PKA signal pathway.
糖尿病认知功能障碍的发病率逐年上升，已逐渐成为研究热点。研究表明胰高血糖素样肽-1 受体（GLP-1R）激动剂可改善糖尿病患者认知功能障碍。本研究聚焦于中药小分子 GLP-1R 激动剂是否能改善糖尿病认知功能障碍。
采用细胞膜色谱（CMC）法，以 GLP-1R-HEK293 细胞膜柱筛选中药小分子。MTT 法、流式细胞术、免疫荧光细胞化学等方法检测槐定碱对高糖（HG）/过氧化氢（HO）诱导 PC12 细胞凋亡率和活性氧（ROS）水平的影响。实时 PCR 检测小鼠大脑皮质中 mRNA 的表达。进一步采用水迷宫实验验证槐定碱对 T2DM 小鼠认知功能障碍的影响。
槐定碱与 GLP-1R 结合，促进 Ca2+内流，增加 β-TC-6 细胞胰岛素分泌和 cAMP 含量。槐定碱增强 HG/HO 损伤 PC12 细胞活力，减轻细胞凋亡，降低细胞内 ROS 水平。槐定碱降低 T2DM 小鼠的逃避潜伏期，改善神经元细胞损伤，降低大脑皮质组织中 Pik3ca、Akt1 和 Mapk1mRNA 的表达。
结果表明，槐定碱通过激活 GLP-1R/cAMP/PKA 信号通路改善 T2DM 小鼠认知功能障碍。
