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

Poster Board Number: E232

Jianguo Wang (Rhode island Hospital, Warren Alpert Medical School of Brown University), Thomas Zhao (Roger Williams Medical Center, Boston University School of Medicine), Naohiro Yano (Rhode island Hospital, Warren Alpert Medical School of Brown University), Ting Zhao (Rhode island Hospital, Warren Alpert Medical School of Brown University)

Background: p38 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.

Methods: PRAK 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.

Results: PRAK 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).

Conclusion: Our 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.

Support or Funding Information

The study was supported by National Heart, Lung, and Blood Institute Grants (R01 HL089405 and R01 HL115265) and National Institute of General Medical Sciences (GM 141339)

lt;pgt;The study was supported by National Heart, Lung, and Blood Institute Grants (R01 HL089405 and R01 HL115265) and National Institute of General Medical Sciences (GM 141339)lt;/pgt;