PPARβ/δ prevents endoplasmic reticulum stress-associated inflammation and insulin resistance in skeletal muscle cells through an AMPK-dependent mechanism

• Main Authors: Salvadó, Laia, Barroso, Emma, Gómez-Foix, Anna Maria, Palomer, Xavier, Michalik, Liliane, Wahli, Walter, Vázquez-Carrera, Manuel
• Other Authors: Lee Kong Chian School of Medicine (LKCMedicine)
• Format: Article
• Language: English
• Published: 2014
• Subjects: DRNTU::Science::Medicine
• Online Access: https://hdl.handle.net/10356/105878; http://hdl.handle.net/10220/20936
• Institution: Nanyang Technological University

Aim/hypothesis Endoplasmic reticulum (ER) stress, which is involved in the link between inflammation and insulin resistance, contributes to the development of type 2 diabetes mellitus. In this study, we assessed whether peroxisome proliferator-activated receptor (PPAR)β/δ prevented ER stress-associated inflammation and insulin resistance in skeletal muscle cells. Methods Studies were conducted in mouse C2C12 myotubes, in the human myogenic cell line LHCN-M2 and in skeletal muscle from wild-type and PPARβ/δ-deficient mice and mice exposed to a high-fat diet. Results The PPARβ/δ agonist GW501516 prevented lipid-induced ER stress in mouse and human myotubes and in skeletal muscle of mice fed a high-fat diet. PPARβ/δ activation also prevented thapsigargin- and tunicamycin-induced ER stress in human and murine skeletal muscle cells. In agreement with this, PPARβ/δ activation prevented ER stress-associated inflammation and insulin resistance, and glucose-intolerant PPARβ/δ-deficient mice showed increased phosphorylated levels of inositol-requiring 1 transmembrane kinase/endonuclease-1α in skeletal muscle. Our findings demonstrate that PPARβ/δ activation prevents ER stress through the activation of AMP-activated protein kinase (AMPK), and the subsequent inhibition of extracellular-signal-regulated kinase (ERK)1/2 due to the inhibitory crosstalk between AMPK and ERK1/2, since overexpression of a dominant negative AMPK construct (K45R) reversed the effects attained by PPARβ/δ activation. Conclusions/interpretation Overall, these findings indicate that PPARβ/δ prevents ER stress, inflammation and insulin resistance in skeletal muscle cells by activating AMPK.