Inhibition of p66ShcA longevity gene rescues podocytes from HIV-1-induced oxidative stress and apoptosis

J Biol Chem. 2009 Jun 12;284(24):16648-16658. doi: 10.1074/jbc.M109.008482. Epub 2009 Apr 21.

Abstract

Glomerular visceral epithelial cells (podocytes) play a critical role in the pathogenesis of human immunodeficiency virus (HIV)-associated nephropathy. A key question concerns the mechanism(s) by which the HIV-1 genome alters the phenotype of the highly specialized, terminally differentiated podocytes. Here, using an in vitro system of conditionally immortalized differentiated human podocytes (CIDHPs), we document a pivotal role for the p66ShcA protein in HIV-1-induced reactive oxygen species generation and CIDHP apoptosis. CIDHP transfected with truncated HIV-1 construct (NL4-3) exhibit increased reactive oxygen species metabolism, DNA strand breaks, and a 5-fold increase in apoptosis, whereas the opposite was true for NL4-3/CIDHP co-transfected with mu-36p66ShcA (micro-36) dominant negative expression vector or isoform-specific p66-small interfering RNA. Phosphorylation at Ser-36 of the wild type p66ShcA protein, required for p66ShcA redox function and inhibition of the potent stress response regulator Foxo3a, was unchanged in micro-36/NL4-3/CIDHP but increased in NL4-3/CIDHP. Acute knockdown of Foxo3a by small interfering RNA induced a 50% increase in micro-36/NL4-3/CIDHP apoptosis, indicating that Foxo3a-dependent responses promote the survival phenotype in micro-36 cells. We conclude that inhibition of p66ShcA redox activity prevents generation of HIV-1 stress signals and activation of the CIDHP apoptosis program.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Active Transport, Cell Nucleus / physiology
  • Apoptosis / physiology*
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Cell Adhesion Molecules, Neuronal
  • Cell Line, Transformed
  • Forkhead Box Protein O3
  • Forkhead Transcription Factors / metabolism
  • Green Fluorescent Proteins / genetics
  • HIV Infections / metabolism
  • HIV Infections / pathology*
  • HIV-1*
  • Humans
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Oxidative Stress / physiology*
  • Phenotype
  • Phosphorylation / physiology
  • Podocytes* / cytology
  • Podocytes* / metabolism
  • Podocytes* / virology
  • RNA, Small Interfering
  • Reactive Oxygen Species / metabolism
  • Shc Signaling Adaptor Proteins / genetics*
  • Shc Signaling Adaptor Proteins / metabolism
  • Src Homology 2 Domain-Containing, Transforming Protein 1
  • Threonine / metabolism
  • Transfection

Substances

  • Carrier Proteins
  • Cell Adhesion Molecules, Neuronal
  • FOXO3 protein, human
  • Forkhead Box Protein O3
  • Forkhead Transcription Factors
  • Membrane Proteins
  • NLGN4X protein, human
  • RNA, Small Interfering
  • Reactive Oxygen Species
  • SHC1 protein, human
  • Shc Signaling Adaptor Proteins
  • Src Homology 2 Domain-Containing, Transforming Protein 1
  • Green Fluorescent Proteins
  • Threonine