通过调节氨基酸介导的mTORC1激活,RAP1A可以抑制肝肥胖症
Heena Agarwal1,2, Yating Wang1,2,3, Brea Tinsley1,2
1Department of Medicine, Columbia University Medical Center, New York, NY, USA.
JHEP reports : innovation in hepatology
|March 24, 2025
概括
激活肝脏RAP1A通过减少肝脏脂肪和纤维化来对抗与代谢功能障碍相关的脂肪性肝病 (MASLD) 和脂肪性肝炎 (MASH). 这通过降低氨基酸吸收,抑制mTORC1和减少SREBP1裂变来实现.
科学领域:
- 肝病学 肝病学是一种肝病学.
- 分子生物学分子生物学
- 代谢疾病 代谢疾病
背景情况:
- 与代谢功能障碍相关的脂肪性肝病 (MASLD) 涉及肝脏三糖的积累.
- 推动MASLD及其渐进形式MASH的分子机制需要进一步阐明.
- 研究了肝脏GTPase RAP1A在MASLD病变发生中的作用.
研究的目的:
- 研究肝脏GTPase RAP1A在MASLD和MASH中的作用.
- 阐明RAP1A通过哪些分子途径影响肝脏脂肪和纤维化.
- 为了确定RAP1A水平是否在MASH患者和肥胖小鼠中发生变化.
主要方法:
- 在小鼠中使用AAV8-TBG载体和小分子激活剂对RAP1A进行基因沉默和激活.
- 使用初级肝细胞探索分子通路的实验.
- 分析MASH患者和对照组肝脏样本的活性RAP1A水平.
主要成果:
- 肝脏RAP1A的激活减少了肥胖小鼠肝脏肥胖和TG积累.
- RAP1A激活通过减少氨基酸吸收来抑制mTORC1信号,随后减少SREBP1裂变.
- 在接受MASH诱导饮食的小鼠和人类MASH肝样本中,活性RAP1A水平显著降低.
- 在小鼠中恢复RAP1A活动可以缓解肝纤维化,而沉默则促进MASH的进展.
结论:
- 肝脏RAP1A激活通过抑制氨基酸介导mTORC1激活和SREBP1裂变来改善MASLD和MASH.
- RAP1A作为关键调节剂,将肥胖与MASLD和MASH发展联系起来.
- 这些发现为氨基酸介导的mTORC1调节提供了机制性的见解,并突出了RAP1A作为潜在的治疗点.
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