Central Role for Adipocyte Na,K-ATPase Oxidant Amplification Loop in the Pathogenesis of Experimental Uremic Cardiomyopathy

J Am Soc Nephrol. 2020 Aug;31(8):1746-1760. doi: 10.1681/ASN.2019101070. Epub 2020 Jun 25.

Abstract

Background: Oxidative stress in adipocyte plays a central role in the pathogenesis of obesity as well as in the associated cardiovascular complications. The putative uremic toxin indoxyl sulfate induces oxidative stress and dramatically alters adipocyte phenotype in vitro. Mice that have undergone partial nephrectomy serve as an experimental model of uremic cardiomyopathy. This study examined the effects on adipocytes of administering a peptide that reduces oxidative stress to the mouse model.

Methods: A lentivirus vector introduced the peptide NaKtide with an adiponectin promoter into the mouse model of experimental uremic cardiomyopathy, intraperitoneally. Then adipocyte-specific expression of the peptide was assessed for mice fed a standard diet compared with mice fed a western diet enriched in fat and fructose.

Results: Partial nephrectomy induced cardiomyopathy and anemia in the mice, introducing oxidant stress and an altered molecular phenotype of adipocytes that increased production of systemic inflammatory cytokines instead of accumulating lipids, within 4 weeks. Consumption of a western diet significantly worsened the adipocyte oxidant stress, but expression of NaKtide in adipocytes completely prevented the worsening. The peptide-carrying lentivirus achieved comparable expression in skeletal muscle, but did not ameliorate the disease phenotype.

Conclusions: Adipocyte-specific expression of NaKtide, introduced with a lentiviral vector, significantly ameliorated adipocyte dysfunction and uremic cardiomyopathy in partially nephrectomized mice. These data suggest that the redox state of adipocytes controls the development of uremic cardiomyopathy in mice subjected to partial nephrectomy. If confirmed in humans, the oxidative state of adipocytes may be a therapeutic target in chronic renal failure.

Keywords: adipocyte; cardiovascular disease; chronic kidney disease; obesity; oxidative stress; uremia.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Retracted Publication

MeSH terms

  • Adipocytes / metabolism*
  • Animals
  • Apoptosis
  • Cardiomyopathies / etiology*
  • Disease Models, Animal
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Nephrectomy
  • Oxidative Stress
  • Peptide Fragments / physiology*
  • Sodium-Potassium-Exchanging ATPase / physiology*
  • Uremia / complications*

Substances

  • NaKtide
  • Peptide Fragments
  • Sodium-Potassium-Exchanging ATPase