SIV Infection and the HIV Proteins Tat and Nef Induce Senescence in Adipose Tissue and Human Adipose Stem Cells, Resulting in Adipocyte Dysfunction.

Jennifer Gorwood,Véronique Béréziat,Matthieu Mantecon,Michael Atlan,Cindy Rose,Christine Bourgeois,Jacqueline Capeau,Olivier Lambotte,Claire Lagathu,Roger Le Grand,Bruno Fève,Delphine Desjardins,Tina Ejlalmanesh

doi:10.3390/cells9040854

Abstract

Background: Aging is characterized by adipose tissue senescence, inflammation, and fibrosis, with trunk fat accumulation. Aging HIV-infected patients have a higher risk of trunk fat accumulation than uninfected individuals—suggesting that viral infection has a role in adipose tissue aging. We previously demonstrated that HIV/SIV infection and the Tat and Nef viral proteins were responsible for adipose tissue fibrosis and impaired adipogenesis. We hypothesized that SIV/HIV infection and viral proteins could induce adipose tissue senescence and thus lead to adipocyte dysfunctions. Methods: Features of tissue senescence were evaluated in subcutaneous and visceral adipose tissues of SIV-infected macaques and in human adipose stem cells (ASCs) exposed to Tat or Nef for up to 30 days. Results: p16 expression and p53 activation were higher in adipose tissue of SIV-infected macaques than in control macaques, indicating adipose tissue senescence. Tat and Nef induced higher senescence in ASCs, characterized by higher levels of senescence-associated beta-galactosidase activity, p16 expression, and p53 activation vs. control cells. Treatment with Tat and Nef also induced oxidative stress and mitochondrial dysfunction. Prevention of oxidative stress (using N-acetyl-cysteine) reduced senescence in ASCs. Adipocytes having differentiated from Nef-treated ASCs displayed alterations in adipogenesis with lower levels of triglyceride accumulation and adipocyte marker expression and secretion, and insulin resistance. Conclusion: HIV/SIV promotes adipose tissue senescence, which in turn may alter adipocyte function and contribute to insulin resistance.

Highlights

Aging is a major issue in the general population; it is associated with adipose tissue senescence, inflammation, and fibrosis, leading to trunk fat redistribution [1,2,3]
We observed that visceral adipose tissue (VAT) and subcutaneous adipose tissue (SCAT) p16 expression was higher in infected macaques than in control macaques (Figure 1A)
P16 level and p53 activation in SCAT or VAT did not correlate with viral load, suggesting that the level of senescence was not linked to the severity of SIV infection

Summary

Introduction

Aging is a major issue in the general population; it is associated with adipose tissue senescence, inflammation, and fibrosis, leading to trunk fat redistribution [1,2,3]. We sought to determine whether or not SIV/HIV-infected adipose tissue displayed features of accentuated aging that could contribute to cardiometabolic disorders. Aging is characterized by adipose tissue senescence, inflammation, and fibrosis, with trunk fat accumulation. Aging HIV-infected patients have a higher risk of trunk fat accumulation than uninfected individuals—suggesting that viral infection has a role in adipose tissue aging. We previously demonstrated that HIV/SIV infection and the Tat and Nef viral proteins were responsible for adipose tissue fibrosis and impaired adipogenesis. We hypothesized that SIV/HIV infection and viral proteins could induce adipose tissue senescence and lead to adipocyte dysfunctions

Objectives

Methods

Results

Conclusion