Pyruvate dehydrogenase inhibition by the inflammatory cytokine TNFα contributes to the pathogenesis of pulmonary arterial hypertension

J Mol Med (Berl). 2011 Aug;89(8):771-83. doi: 10.1007/s00109-011-0762-2. Epub 2011 Aug 2.


Pulmonary arterial hypertension (PAH) is a vascular remodeling disease characterized by enhanced proliferation and suppressed apoptosis of pulmonary artery smooth muscle cells (PASMC). This apoptosis resistance is characterized by PASMC mitochondrial hyperpolarization [in part, due to decreased pyruvate dehydrogenase (PDH) activity], decreased mitochondrial reactive oxygen species (mROS), downregulation of Kv1.5, increased [Ca(++)](i), and activation of the transcription factor nuclear factor of activated T cells (NFAT). Inflammatory cells are present within and around the remodeled arteries and patients with PAH have elevated levels of inflammatory cytokines, including tumor necrosis factor-α (TNFα). We hypothesized that the inflammatory cytokine TNFα inhibits PASMC PDH activity, inducing a PAH phenotype in normal PASMC. We exposed normal human PASMC to recombinant human TNFα and measured PDH activity. In TNFα-treated cells, PDH activity was significantly decreased. Similar to exogenous TNFα, endogenous TNFα secreted from activated human CD8(+) T cells, but not quiescent T cells, caused mitochondrial hyperpolarization, decreased mROS, decreased K(+) current, increased [Ca(++)](i), and activated NFAT in normal human PASMC. A TNFα antibody completely prevented, while recombinant TNFα mimicked the T cell-induced effects. In vivo, the TNFα antagonist etanercept prevented and reversed monocrotaline (MCT)-induced PAH. In a separate model, T cell deficient rats developed less severe MCT-induced PAH compared to their controls. We show that TNFα can inhibit PASMC PDH activity and induce a PAH phenotype. Our work supports the use of anti-inflammatory therapies for PAH.

MeSH terms

  • Animals
  • Etanercept
  • Familial Primary Pulmonary Hypertension
  • Glycogen Synthase Kinase 3 / metabolism
  • Glycogen Synthase Kinase 3 beta
  • Humans
  • Hypertension, Pulmonary / enzymology*
  • Hypertension, Pulmonary / etiology*
  • Hypertension, Pulmonary / pathology
  • Hypertension, Pulmonary / physiopathology
  • Immunoglobulin G / pharmacology
  • Inflammation Mediators / metabolism*
  • Ion Channel Gating / drug effects
  • Ketone Oxidoreductases / antagonists & inhibitors*
  • Ketone Oxidoreductases / metabolism
  • Kv1.5 Potassium Channel / metabolism
  • Models, Biological
  • Monocrotaline
  • Myocytes, Smooth Muscle / drug effects
  • Myocytes, Smooth Muscle / enzymology
  • Myocytes, Smooth Muscle / pathology
  • Phenotype
  • Pulmonary Artery / pathology
  • Rats
  • Receptors, Tumor Necrosis Factor
  • Tumor Necrosis Factor-alpha / antagonists & inhibitors
  • Tumor Necrosis Factor-alpha / metabolism*
  • Tumor Necrosis Factor-alpha / pharmacology


  • Immunoglobulin G
  • Inflammation Mediators
  • Kv1.5 Potassium Channel
  • Receptors, Tumor Necrosis Factor
  • Tumor Necrosis Factor-alpha
  • Monocrotaline
  • Ketone Oxidoreductases
  • pyruvate dehydrogenase (NADP+)
  • Glycogen Synthase Kinase 3 beta
  • Glycogen Synthase Kinase 3
  • Etanercept