Institute of Molecular Biosciences, University of Graz, Graz, Austria.
Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, Graz, Austria.
Commun Biol. 2021 Mar 10;4(1):323. doi: 10.1038/s42003-021-01858-z.
Modulation of adipocyte lipolysis represents an attractive approach to treat metabolic diseases. Lipolysis mainly depends on two enzymes: adipose triglyceride lipase and hormone-sensitive lipase (HSL). Here, we investigated the short- and long-term impact of adipocyte HSL on energy homeostasis using adipocyte-specific HSL knockout (AHKO) mice. AHKO mice fed high-fat-diet (HFD) progressively developed lipodystrophy accompanied by excessive hepatic lipid accumulation. The increased hepatic triglyceride deposition was due to induced de novo lipogenesis driven by increased fatty acid release from adipose tissue during refeeding related to defective insulin signaling in adipose tissue. Remarkably, the fatty liver of HFD-fed AHKO mice reversed with advanced age. The reversal of fatty liver coincided with a pronounced lipodystrophic phenotype leading to blunted lipolytic activity in adipose tissue. Overall, we demonstrate that impaired adipocyte HSL-mediated lipolysis affects systemic energy homeostasis in AHKO mice, whereby with older age, these mice reverse their fatty liver despite advanced lipodystrophy.
脂肪细胞脂解的调节代表了治疗代谢疾病的一种有吸引力的方法。脂解主要依赖于两种酶:脂肪甘油三酯脂肪酶和激素敏感脂肪酶(HSL)。在这里,我们使用脂肪细胞特异性 HSL 敲除(AHKO)小鼠研究了脂肪细胞 HSL 对能量平衡的短期和长期影响。喂食高脂肪饮食(HFD)的 AHKO 小鼠逐渐发展为脂肪营养不良,伴有肝内脂质过度积累。肝内甘油三酯沉积的增加是由于重新进食时脂肪组织中脂肪酸释放增加引起的从头合成增加所致,这与脂肪组织中胰岛素信号缺陷有关。值得注意的是,喂食 HFD 的 AHKO 小鼠的脂肪肝随着年龄的增长而逆转。脂肪肝的逆转与明显的脂肪营养不良表型相吻合,导致脂肪组织的脂解活性减弱。总的来说,我们证明了脂肪细胞 HSL 介导的脂解受损会影响 AHKO 小鼠的全身能量平衡,随着年龄的增长,尽管脂肪营养不良加重,这些小鼠仍会逆转其脂肪肝。