1. Inhibition of p66ShcA longevity gene rescues podocytes from HIV-1-induced oxidative stress and apoptosis.
- Author
-
Husain M, Meggs LG, Vashistha H, Simoes S, Griffiths KO, Kumar D, Mikulak J, Mathieson PW, Saleem MA, Del Valle L, Pina-Oviedo S, Wang JY, Seshan SV, Malhotra A, Reiss K, and Singhal PC
- Subjects
- Active Transport, Cell Nucleus 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, Humans, Membrane Proteins genetics, Membrane Proteins metabolism, Phenotype, Phosphorylation physiology, RNA, Small Interfering, Reactive Oxygen Species metabolism, Shc Signaling Adaptor Proteins metabolism, Src Homology 2 Domain-Containing, Transforming Protein 1, Threonine metabolism, Transfection, Apoptosis physiology, HIV Infections pathology, HIV-1, Oxidative Stress physiology, Podocytes cytology, Podocytes metabolism, Podocytes virology, Shc Signaling Adaptor Proteins genetics
- 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.
- Published
- 2009
- Full Text
- View/download PDF