Pgc-1α Promotes Phosphorylation, Inflammation, and Apoptosis in H9c2 Cells During the Early Stage of Lipopolysaccharide Induction

Inflammation. 2021 Oct;44(5):1771-1781. doi: 10.1007/s10753-021-01453-8. Epub 2021 Apr 13.

Abstract

Cardiac dysfunction in severe sepsis is associated with increased mortality. However, the molecular mechanisms underlying septic heart dysfunction remain unclear. Expression of peroxisome proliferator-activated receptor-γ coactivator 1α (Pgc-1α), concentrations of inflammatory factors, and activation of the nuclear factor kappa-B (NF-κB) signaling pathway were examined in H9c2 cells after a 24-h lipopolysaccharide (LPS) stimulation period using qPCR, enzyme-linked immunosorbent assays (ELISAs), and western blots (WBs), respectively. Pgc-1α was overexpressed and suppressed in cells using a lentivirus vector and siRNA, respectively. The effects of Pgc-1α dysfunction on the release of inflammatory factors and apoptosis were analyzed. Pgc-1α expression was increased after LPS induction for 0.5 h and returned to the pre-induction level at 2 h. Levels of IL-1β, IL-6, and TNF-α increase after LPS induction for 0.5 h and accumulated in the culture supernatants over time. The WBs revealed the highest Pgc-1α and phospho (p)-p65 protein levels after LPS induction for 0.5 h, followed by a decrease; moreover, the cleaved-caspase-3 level increased after LPS induction for 0.5 h and increased gradually thereafter. A functional analysis of Pgc-1α revealed that overexpression of this protein enhanced LPS-induced inflammatory factors and p-p65 levels and inhibited apoptosis during the early stage after LPS induction (0.5 and 4 h). In contrast, the inhibition of Pgc-1α expression inhibited the LPS expression-associated increases in inflammatory factors and p-p65 and promoted apoptosis. Pgc-1α promoted LPS-induced p65 phosphorylation and inflammatory factor release while inhibiting apoptosis.

Keywords: LPS;; NF-κB;; Pgc-1α;; inflammation; p65;.

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Apoptosis / physiology
  • Cell Line
  • Inflammation Mediators / metabolism*
  • Lipopolysaccharides / toxicity*
  • Myocytes, Cardiac / drug effects*
  • Myocytes, Cardiac / metabolism*
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha / biosynthesis*
  • Phosphorylation / drug effects
  • Phosphorylation / physiology
  • Rats

Substances

  • Inflammation Mediators
  • Lipopolysaccharides
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha
  • Ppargc1a protein, rat