Ablation of PRAK exacerbates the mitochondria dysfunction in C2C12 myoblasts exposed to palmitate stress

Abstract

Backgroundp38 regulated/activated protein kinase (PRAK) plays a crucial role in modulating survival and metabolism. However, the role of PRAK in the regulation of palmitate‐induced metabolic stress remains unknown. We examined whether deletion of PRAK would suppress cell survival and mitochondrial function and whether PRAK‐induced detrimental effect was mitigated by irisin in C2C12 myoblasts in response to palmitate (PA) stress.MethodsPRAK of C2C12 myoblasts was knocked out by using CRISPR/Cas‐9 genome editing technology. Both wild type and PRAK‐/‐ C2C12 cells were exposed to palmitate at the concentration of 200 mmol/L for 48 h to induce metabolic stress. The effect of irisin, an adipomyokine, on both wild type and PRAK‐/‐cells was determined to explore its relationship with RPAK in response to palmitate stress. Cell viability, ATP product, glucose uptake, mitochondrial membrane potential and mitochondrial swelling were assessed.ResultsPRAK knockout decreased C2C12 viability in response to PA stress as evident by MTT assay in association with the reduction of ATP and glucose uptake. PRAK knockout enhanced apoptosis of C2C12 myoblasts in response to PA treatment, consistent with an impairment in mitochondrial function, by decreasing mitochondrial membrane potential and increasing mitochondrial swelling. However, PRAK knockout induced an impairment of mitochondrial and cell damage in C2C12 cells exposed to PA stress were rescued by treatment of irisin (10ng/ml).ConclusionOur finding indicates a pivotal role of PRAK in preserving cellular survival, mitochondrial function and glucose uptake in C2C12 cells exposed to palmitate induced metabolic stress.