Role of mitochondria in HIV infection and associated metabolic disorders: focus on nonalcoholic fatty liver disease and lipodystrophy syndrome

Biologic aging, frailty, and age-related disease in chronic HIV infection

PURPOSE OF REVIEW

Effective therapies have transformed HIV infection into a chronic disease, and new problems are arising related to aging. This article reviews the aging process, age-related deficit accumulation and frailty, and how these might be affected by chronic HIV infection.

RECENT FINDINGS

Aging is characterized by acceleration in the rate of unrepaired physiologic damage an organism accumulates. HIV infection is associated with many factors that might affect the aging process, including extrinsic behavioral risk factors and co-infections, and multiple intrinsic factors, including intercellular communication, inflammation, and coagulation pathways. Whether each factor affects the aging process, they likely result in an increase in the risk of adverse health outcomes, and so give rise to frailty, likely with several clinical manifestations.

SUMMARY

Age-related deficit accumulation is influenced by both the background or environmental rate of insults an organism sustains and the efficacy of intrinsic damage control and repair mechanisms. Both processes are likely affected in people living with HIV infection.

Targeted SLNs for management of HIV-1 associated dementia

CONTEXT

HIV-1 associated dementia (HAD) is an evolving disease in the category of neurological disorders.

OBJECTIVE

Nifedipine-loaded solid lipid nanoparticles (SLNs) were developed and coated with Tween 80 to facilitate enhanced brain drug delivery for the treatment of HAD.

MATERIALS AND METHODS

SLNs were prepared using solvent injection method. Lipids consisted of tristearin, hydrogenated soya phosphatidylcholine (HSPC) (1.5:1 w/w). Nifedipine was model drug in this study. Tween 80 (0.5% v/v) was taken as key modulator. SLNs were characterized for particle shape, size, zeta potential, entrapment efficiency, in vitro drug release, DNA fragmentation, cytotoxicity potential and in vivo studies.

RESULTS

The SLNs (plain and coated) were found to be in nanometric in size (∼120 nm) with more than 70% entrapment efficiency. In vitro drug release profile reflected sustained release up to 48 h. Tween 80-coated SLNs showed higher percentage of DNA fragmentation in vitro and enhanced cell viability in sulforhodamine assay (rat cortical cells) as compared to plain drug and uncoated SLNs due to facilitated uptake of SLNs and reversal of P-gp efflux by virtue of Tween 80. Biodistribution study performed on vital organs, i.e. brain, heart, liver, spleen, lungs and kidney showed increased accumulation of Tween 80-coated SLNs in the brain.

DISCUSSION AND CONCLUSION

Tween 80 enhanced localization of SLNs in the brain as compared to uncoated SLNs. This approach can be employed effectively to transport chemotherapeutics across the BBB for management of HIV-1 associated dementia and other ailments.

Aging of the human innate immune system in HIV infection

HIV infection is associated with a chronic inflammatory state arising from multiple factors, including innate immune recognition of HIV, increased microbial translocation, and release of endogenous ligands from damaged cells (such as CD4 T cells). In many respects, this heightened pro-inflammatory environment resembles that associated with aging in the absence of HIV infection, and evidence of dysregulated innate immune responses can be found in not only older HIV-negative adults, but also adults with HIV infection. While the study of innate immune aging in HIV infection is still in its early stages, it seems likely that at least additive, or potentially synergistic effects of aging and HIV infection will be found.

An update on the pharmacological strategies in the treatment of HIV-1-associated adipose redistribution syndromes

INTRODUCTION

With the introduction of combination antiretroviral therapy (ART) for HIV infection in the mid-1990s, descriptions of morphological changes and metabolic disturbances in treated patients began to emerge. HIV-1/highly active ART-associated lipodystrophy syndrome (HALS) involves metabolic abnormalities and diverse forms of anomalous fat distribution. The current review focuses on the pathophysiological basis and the clinical evidence for the use of several medical strategies in the management of HALS.

AREAS COVERED

We have covered the most relevant studies related to the pharmacological strategies in the treatment of HALS, with attention to the current and novel antiretroviral agents.

EXPERT OPINION

The most commonly used strategies for HALS reversion have included modification of host-dependent factors, including those related to HIV-1 infection and those associated with ART. Preventive and medical strategies have been associated with moderate success. The only intervention that offers an immediate aesthetical improvement for patients with HALS so far has been plastic surgery.

Molecular mechanisms of liver fibrosis in HIV/HCV coinfection

Chronic hepatitis C virus (HCV) infection is an important cause of morbidity and mortality in people coinfected with human immunodeficiency virus (HIV). Several studies have shown that HIV infection promotes accelerated HCV hepatic fibrosis progression, even with HIV replication under full antiretroviral control. The pathogenesis of accelerated hepatic fibrosis among HIV/HCV coinfected individuals is complex and multifactorial. The most relevant mechanisms involved include direct viral effects, immune/cytokine dysregulation, altered levels of matrix metalloproteinases and fibrosis biomarkers, increased oxidative stress and hepatocyte apoptosis, HIV-associated gut depletion of CD4 cells, and microbial translocation. In addition, metabolic alterations, heavy alcohol use, as well drug use, may have a potential role in liver disease progression. Understanding the pathophysiology and regulation of liver fibrosis in HIV/HCV co-infection may lead to the development of therapeutic strategies for the management of all patients with ongoing liver disease. In this review, we therefore discuss the evidence and potential molecular mechanisms involved in the accelerated liver fibrosis seen in patients coinfected with HIV and HCV.

Viral proteins that bridge unconnected proteins and components in the human PPI network

Viral proteins bridging unconnected components of the Hu-PPI network play a crucial role in viral replication and hence form attractive targets for therapeutic interventions.