通过控制MafA表达,GPRC5B通过控制肥胖的成熟β细胞状态
Tianpeng Wang1, Remy Bonnavion1, Janett Piesker2
1Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany.
JCI insight
|September 4, 2025
概括
在肥胖期间,孤儿受体GPRC5B对维持胰腺β细胞功能至关重要. 通过cAMP/ CREB途径影响β细胞成熟度和MafA表达,其损失会损害胰岛素分泌和葡萄糖耐受性.
科学领域:
- 内分泌学
- 代谢过程
- 分子生物学
背景情况:
- 实验室研究表明孤儿受体GPRC5B会影响胰腺β细胞的存活,增殖和胰岛素分泌.
- 在葡萄糖稳态中GPRC5B的体内作用在很大程度上尚不清楚.
研究的目的:
- 在胰腺β细胞中研究GPRC5B的体内功能,涉及葡萄糖代谢和恒温.
- 阐明GPRC5B影响β细胞功能的分子机制,特别是在肥胖的条件下.
主要方法:
- 产生和利用可诱导塔莫西芬的β细胞特异性GPRC5B淘汰小鼠 (Ins-G5b-KO).
- 在瘦肉和高脂肪食小鼠中评估葡萄糖耐受性和胰岛素分泌.
- 胰腺小岛的流细胞计和单细胞表达分析.
- 对MafA表达及其基因进行定量分析.
- 研究cAMP反应元素结合蛋白 (CREB) 的酸化.
主要成果:
- 在瘦小鼠中,GPRC5B的丧失没有影响β细胞功能.
- 在Ins- G5b- KO患者中,高脂肪饮食引起的肥胖导致胰岛素分泌量显著降低和葡萄糖耐受性受损.
- 肥胖的Ins-G5b-KO表现出降低的β细胞丰度和较不成熟的β细胞表型.
- 在肥胖的Ins- G5b- KO群岛中,MafA及其向基因的表达下调.
- 在肥胖 Ins- G5b- KO 群岛中,CREB 酸化的降低在 MafA 下调之前发生,这表明有机理性联系.
结论:
- 在肥胖期间,GPRC5B在维护β细胞功能和葡萄糖平衡方面发挥着至关重要的作用.
- 在肥胖患者中,GPRC5B通过cAMP/ CREB依赖的MafA表达的调节来保持β细胞成熟度和胰岛素分泌.
- 针对GPRC5B可能是治疗肥胖相关代谢功能障碍的策略.
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