ER Stress Aggravates Diaphragmatic Weakness through Activating PERK/JNK Signaling in Obesity Hypoventilation Syndrome

Obesity hypoventilation syndrome (OHS) is associated with reduced quality of life and increased risk of death. Diaphragmatic dysfunction has been implicated in the pathogenesis of OHS. We found that significant diaphragmatic weakness and lipid accumulation in people with obesity as well as mouse models of obesity, which was associated with activated endoplasmic reticulum (ER) stress indicated by increased PERK signaling and activation of JNK pathway. In cultured myotubes, inhibition of PERK and JNK signaling abrogated the lipids deposition and ameliorated insulin resistance, and inhibition of JNK signaling reversed the impaired elasticity of myotubes induced by lipotoxicity. Collectively, our data suggest that activation of PERK/JNK signaling is an important pathophysiological factor contributing to diaphragmatic contractile dysfunction in OHS. Disclosure X.Xiang: None. Y.Zhu: None. X.Pan: None. W.Xin: None. W.Tang: None. X.He: None. G.Shi: None. Y.Chen: None. Funding National Key R&D Program of China (2017YFA0105803); National Natural Science Foundation of China (82270886, 82070811); 5010 Clinical Research Projects of Sun Yat-sen University (2015015); Science and Technology Plan Project of Guangzhou City (202007040003, 202201020497); Key Area R&D Program of Guangdong Province (2019B020227003); Science and Technology Research Development Program of Guangzhou City (202007040003, 202201020497)