http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Depletion of adipocyte Becn1 leads to lipodystrophy and metabolic dysregulation
Yaechan Song,Young Jin,Yul Ji,Sung Sik Choe,Yong Geun Jeon,Heeju Na,Tae Wook Nam,Hye Jeong Kim,Hahn Nahmgoong,Sung Min Kim,Jae-woo Kim,Ki Taek Nam,Je Kyung Seong,Daehee Hwang,Chan Bae Park,In Hye Lee 한국실험동물학회 2021 한국실험동물학회 학술발표대회 논문집 Vol.2021 No.7
Macroautophagy is a catabolic process that delivers damaged and unnecessary cytosolic contents to lysosomes for removal of defective subcellular organelles and proteins. Becn1 is a key regulator of autophagy, forming a complex with class III phosphatidylinositol 3-kinase (PI3K-III) to initiate autophagosome formation. Although Becn1 has been implicated in numerous diseases such as cancer, aging, and neurodegenerative disease, its function in mature adipocytes remains elusive. In this study, we implemented Adipoq-Cre to generate adipocyte-specific Becn1 KO (BaKO) mice to identify the function of autophagy in adipose tissue homeostasis. BaKO mice naturally developed severe lipodystrophy and metabolic dysregulation, which were exacerbated upon high dietary fat intake. These mice also acquired adipose tissue inflammation, hepatic steatosis, and insulin resistance which advanced to early mortality. Immortalized stromal vascular cells (imSVCs) were established in-vitro to conditionally knock-out Becn1 upon tamoxifen treatment. Ablation of Becn1 in adipocytes led to programmed cell death in a cell-autonomous manner, accompanied by elevated endoplasmic reticulum (ER) stress gene expression. Furthermore, we observed that Becn1 depletion sensitized mature adipocytes to ER stress through activation of protein kinase R-like ER kinase (PERK) – eukaryotic initiation factor 2α (eiF2α) axis. This led to excessive unfolded protein response (UPR) and accelerated cell death through notable induction of C/EBP homologous protein (CHOP) and Bax expression. Taken together, these data suggest that adipocyte-Becn1 would serve as a crucial player for adipocyte survival and adipose tissue homeostasis.