Adiponectin reduces ER stress-induced apoptosis through PPAR alpha transcriptional regulation of ATF2 in mouse adipose

作者：Liu, Zhenjiang; Gan, Lu; Wu, Tianjiao; Feng, Fei; Luo, Dan; Gu, Huihui; Liu, Shimin; Sun, Chao^*

来源：Cell Death & Disease, 2016, 7(11): e2487.

DOI：10.1038/cddis.2016.388

• ENDOPLASMIC-RETICULUM STRESS
• ACTIVATED PROTEIN-KINASE
• FATTY-ACID OXIDATION
• INSULIN-RESISTANCE
• SIGNALING PATHWAY
• LIPID-METABOLISM
• CELL APOPTOSIS
• LINKS OBESITY
• ADIPOCYTES
• PHOSPHORYLATION

Adiponectin is a cytokine produced predominantly by adipose tissue and correlates with glucose and lipid homeostasis. However, the effects of adiponectin on endoplasmic reticulum (ER) stress and apoptosis of adipose tissue remain elusive. In this study, we found that tunicamycin-induced ER stress increased serum free fatty acid (FFA) and impaired glucose tolerance, elevated the mRNA levels of GRP78, Chop, ATF2 and caspase 3, but reduced adiponectin mRNA level in white adipose tissue. Moreover, ER stress-triggered adipocyte apoptosis by increasing cellular FFA level and Ca2+ level. Further analysis revealed that adiponectin alleviated ER stress-induced adipocyte apoptosis by elevating peroxisome proliferator-activated receptor alpha (PPAR alpha) mRNA level. Our data also confirmed that adiponectin reduced early apoptotic cells and blocked the mitochondrial apoptosis pathway by activating the AdipoR1/AMP-activated protein kinase (AMPK) signal pathway. In addition, PPARa bound to ATF2 promoter region and inhibited transcription of ATF2. The inhibition of adipocyte apoptosis by adiponectin was correlated with transcriptional suppression of ATF2. Furthermore, adiponectin inhibited ER stress-induced apoptosis by activating the AMPK/PKC pathway. In summary, our data demonstrate adiponectin inhibited ER stress and apoptosis of adipocyte in vivo and in vitro by activating the AMPK/PPAR alpha/ATF2 pathway. Our study establishes that adiponectin is an important adipocytokine for preventing and treating obesity.

• 出版日期2016-11
• 单位西北农林科技大学