Bone and fat cross-talk in antiretroviral therapy (ART) treated HIV patients - Project Summary / Abstract
The widespread use of combination antiretroviral therapy (cART) has significantly increased the lifespan of
people living with HIV (PLWH). As HIV has become a chronic disease, there is a growing concern of the
disproportionate risk of a variety of comorbidities. Two such comorbidities that occur at a higher prevalence in
cART treated PLWH include bone loss and fat gain. Interestingly, as new treatment recommendations have
shifted to cART regimens that are less bone toxic, there appears to be an increased prevalence of excessive
fat gain and an increased risk for the development of metabolic syndrome. Our long-term goal is to determine
the mechanisms contributing to these comorbid conditions in cART treated PLWH in order to find less
deleterious treatment options. The current proposal will test the central hypothesis that the hormonal
communication between bone and fat explains how antiretrovirals (ARVs) contribute to bone loss and fat gain
in PLWH. Our hypothesis is based on our preliminary data showing hormonal changes in response to ARVs
and correlations between the changes in bone and fat hormones and BMD loss and fat gain with cART
initiation. To test our hypothesis, we propose to take a hierarchical approach that will include in vitro,
preclinical, and human subject studies. In Aim 1, we will define the contribution of individual ARVs and cART to
bone and fat cellular function and hormonal production using primary human cells. In Aim 2, we will investigate
the skeletal and metabolic response to individual ARVs and cART using both an uninfected wild-type mouse
and a humanized mouse model of HIV-infection. Finally, in Aim 3, we will determine the association between
bone and fat-derived hormones and bone mass and body composition in three critical treatment stages, cART
initiation, long-term stable cART treatment, and switching cART regimens. If successful, this proposal,
submitted by an early stage investigator (ESI), will provide significant insights into key comorbidities faced by
HIV patients on cART—specifically by illuminating how individual ARVs negatively affect bone/fat cell function
and hormonal production. At the same time, this proposal will increase our general understanding of the bone-
fat hormonal axis.