自由脂肪酸受体4激动剂通过不同机制刺激小鼠与人群的胰岛素分泌
bioRxiv : the preprint server for biology
|September 2, 2025
概括
自由脂肪酸受体FFAR4的激活会增加胰岛素的分泌. 在小鼠中,这种作用通过间接的体位素抑制发生,而人类小岛则表现出直接的β细胞作用,突出了FFAR4疗法的物种差异.
科学领域:
- 内分泌学
- 分子药理学
- 细胞生物学
背景情况:
- 在胰腺小岛中存在自由脂肪酸受体4 (FFAR4).
- 激活FFAR4会影响胰岛素和体静止素的分泌.
研究的目的:
- 阐明FFAR4对小鼠和人类小岛的激素分泌的作用机制.
- 研究FFAR4信号通路中的特定物种差异.
主要方法:
- 在小鼠和人类小岛上使用FFAR4激素化合物A (Cpd A),包括转基因模型 (delta细胞切除,SST切除,Gαz切除).
- 检查了纯化的小鼠β和delta细胞,人类EndoC-bH5细胞和人类小岛.
- 在特定细胞类型和小岛中测量Cpd A的Ca++动态.
主要成果:
- 在小鼠中,Cpd A的胰岛素作用在被切除的三角细胞和缺乏SST的小岛中被消除,而在纯化的β细胞中则不存在.
- Gαz删除影响了Cpd A对SST分泌的抑制,但没有影响胰岛素的强化.
- 在小鼠三角细胞中减少了Cpd A Ca++过渡物,这种效应在缺乏Gαz的小岛上丧失.
- 在人群小岛中,FFAR4的激活增强了胰岛素分泌和Ca++的短暂性,独立于SST.
- 在人类EndoC-bH5细胞中直接增强胰岛素分泌.
结论:
- 通过Gαz合的SST抑制,FFAR4对小鼠胰岛素的刺激是间接的.
- 人类胰岛素通过FFAR4激活释放是一种直接的β细胞效应.
- 在FFAR4信号传递中发现了与物种相关的显著差异,这对于针对代谢疾病的治疗开发至关重要.
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