HIV Promotes NLRP3 Inflammasome Complex Activation in Murine HIV-Associated Nephropathy

Publication Date

2016

Journal Title

Am J Pathol

Abstract

Dysregulated growth and loss of podocytes are important features of HIV-associated nephropathy. Recently, HIV was reported to induce a new type of programed cell death, pyroptosis, in T lymphocytes through induction of Nod-like receptor protein 3 (NLRP3) inflammasome complexes. We evaluated the role of HIV in podocyte NLRP3 inflammasome formation both in vivo and in vitro. Renal cortical sections of HIV-transgenic mice (Tg26) displayed increased expression of NLRP3, ASC (a CARD protein), caspase-1, and IL-1beta proteins, confirming NLRP3 inflammasome complex formation in podocytes of Tg26 mice. Renal tissues of Tg26 mice also displayed enhanced mRNA levels and protein expressions of inflammasome markers (NLRP3, ASC, and caspase-1, and IL-1beta). Serum of Tg26 mice also showed elevated concentrations of IL-1beta cytokine compared with FVBN mice. HIV induced pyroptosis in a dose- and time-dependent manner within podocytes, a phenotype of inflammasome activation. Caspase-1 inhibitor not only attenuated podocyte expression of caspase-1 and IL-1beta but also provided protection against pyroptosis, suggesting that HIV-induced podocyte injury was mediated by caspase-1 activation. Interestingly, HIV-induced podocyte pyroptosis could be partially inhibited by Tempol (a superoxide dismutase-mimetic agent) and by glyburide (an inhibitor of potassium efflux). These findings suggest that generation of reactive oxygen species and potassium efflux contribute to HIV-induced pyroptosis and NLRP3 inflammasome activation in podocytes.

Volume Number

186

Issue Number

2

Pages

347-58

Document Type

Article

EPub Date

2015/12/20

Status

Faculty, Northwell Researcher

Facility

School of Medicine; Northwell Health

Primary Department

Nephrology

PMID

26683666

DOI

10.1016/j.ajpath.2015.10.002

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