自噬减少是 NAFLD 的早期特征,肝脏特异性 PARKIN 敲除会加速脂肪变性、炎症和纤维化的发生。
Reduced mitophagy is an early feature of NAFLD and liver-specific PARKIN knockout hastens the onset of steatosis, inflammation and fibrosis.
机构信息
Division of Endocrinology and Metabolism, Department of Medicine, School of Medicine, University of Pittsburgh, 200 Lothrop Street, BST W1060, Pittsburgh, PA, 15213, USA.
Department of Cell Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA, USA.
出版信息
Sci Rep. 2023 May 10;13(1):7575. doi: 10.1038/s41598-023-34710-x.
Nonalcoholic fatty liver disease (NAFLD) encompasses a spectrum of pathologies that includes steatosis, steatohepatitis (NASH) and fibrosis and is strongly associated with insulin resistance and type 2 diabetes. Changes in mitochondrial function are implicated in the pathogenesis of NAFLD, particularly in the transition from steatosis to NASH. Mitophagy is a mitochondrial quality control mechanism that allows for the selective removal of damaged mitochondria from the cell via the autophagy pathway. While past work demonstrated a negative association between liver fat content and rates of mitophagy, when changes in mitophagy occur during the pathogenesis of NAFLD and whether such changes contribute to the primary endpoints associated with the disease are currently poorly defined. We therefore undertook the studies described here to establish when alterations in mitophagy occur during the pathogenesis of NAFLD, as well as to determine the effects of genetic inhibition of mitophagy via conditional deletion of a key mitophagy regulator, PARKIN, on the development of steatosis, insulin resistance, inflammation and fibrosis. We find that loss of mitophagy occurs early in the pathogenesis of NAFLD and that loss of PARKIN accelerates the onset of key NAFLD disease features. These observations suggest that loss of mitochondrial quality control in response to nutritional stress may contribute to mitochondrial dysfunction and the pathogenesis of NAFLD.
非酒精性脂肪性肝病 (NAFLD) 涵盖了一系列病理学特征,包括脂肪变性、脂肪性肝炎 (NASH) 和纤维化,并且与胰岛素抵抗和 2 型糖尿病密切相关。线粒体功能的变化与 NAFLD 的发病机制有关,特别是在脂肪变性向 NASH 的转变过程中。自噬是一种线粒体质量控制机制,允许通过自噬途径从细胞中选择性去除受损的线粒体。虽然过去的研究表明肝脏脂肪含量与自噬率之间存在负相关,但在 NAFLD 的发病机制中自噬发生变化时,以及这种变化是否会导致与疾病相关的主要终点,目前还定义不明确。因此,我们进行了这里描述的研究,以确定在 NAFLD 的发病机制中自噬发生变化的时间,以及通过条件性敲除关键自噬调节剂 PARKIN 来抑制自噬对脂肪变性、胰岛素抵抗、炎症和纤维化的发展的影响。我们发现自噬在 NAFLD 的发病机制早期就发生了变化,并且 PARKIN 的缺失加速了 NAFLD 疾病特征的发生。这些观察结果表明,营养应激反应中失去线粒体质量控制可能导致线粒体功能障碍和 NAFLD 的发病机制。