Mitochondrial interference by anti-HIV drugs: mechanisms beyond Pol-γ inhibition

Roles of X-box binding protein 1 in liver pathogenesis

The prevalence of drug-induced liver injury (DILI) and viral liver infections presents significant challenges in modern healthcare and contributes to considerable morbidity and mortality worldwide. Concurrently, metabolic dysfunctionassociated steatotic liver disease (MASLD) has emerged as a major public health concern, reflecting the increasing rates of obesity and leading to more severe complications such as fibrosis and hepatocellular carcinoma. X-box binding protein 1 (XBP1) is a distinct transcription factor with a basic-region leucine zipper structure, whose activity is regulated by alternative splicing in response to disruptions in endoplasmic reticulum (ER) homeostasis and the unfolded protein response (UPR) activation. XBP1 interacts with a key signaling component of the highly conserved UPR and is critical in determining cell fate when responding to ER stress in liver diseases. This review aims to elucidate the emerging roles and molecular mechanisms of XBP1 in liver pathogenesis, focusing on its involvement in DILI, viral liver infections, MASLD, fibrosis/cirrhosis, and liver cancer. Understanding the multifaceted functions of XBP1 in these liver diseases offers insights into potential therapeutic strategies to restore ER homeostasis and mitigate liver damage.

Biosafety assessment of novel organoselenium zidovudine derivatives in the Caenorhabditis elegans model

Antiretrovirals have improved considerably since the introduction of 3'-azido-3'-deoxythymidine (zidovudine or AZT), a molecule with also anticancer effects. Subsequently, a variety of other nucleosides have been synthesized. However, these medications are often associated with serious adverse events and the onset or exacerbation of degenerative processes, diseases, and syndromes, affecting mainly the mitochondria. In this study, we used Caenorhabditis elegans to investigate the toxicity potential of AZT and three new organoselenium derivatives with modifications in the 5' position of the sugar ring in place of the 5'-OH group, with the insertion of a neutral, an electron-withdrawing and an electron-donating group attached to the aryl selenol moiety: 5'-seleno-(4-chloro-phenyl)-3-(amino)-thymidine (ASAT-4-Cl), 5'-seleno-(phenyl)-3-(amino)-thymidine (ASAT-Ph), and 5'-seleno-(4-methoxyphenyl)-3-(amino)- thymidine (ASAT-4-OMe). Analyzes included worm survival, behavior parameters, high-resolution respirometry, citrate synthase activity, and ATP levels. Although all compounds negatively affected C. elegans, ASAT-4-Cl and ASAT-Ph showed lower toxicity compared to AZT, especially in mitochondrial viability and ATP production. Therefore, more studies must be carried out on the use of these new compounds as pharmacological interventions.

The Role of Tumor Suppressor p53 Protein in HIV-Host Cell Interactions

The virus-host relationship is indispensable for executing successful viral infection. The pathogenesis of HIV is determined by an intricate interaction between the host and the virus for the regulation of HIV infection, thereby influencing various aspects, including the regulation of signaling pathways. High mutation rates and population heterogeneity characterize HIV with consequences for viral pathogenesis and the potential to escape the immune system and anti-viral inhibitors used in therapy. The origin of the high mutation rates exhibited by HIV may be attributed to a limited template-copied fidelity that likely operates in the cytoplasm. HIV-1 infection induces upregulation and activation of tumor suppressor p53 protein in the early stages of HIV-1 infection. p53 plays a multifaceted role in the context of HIV infection, thereby affecting viral replication. p53 is involved in maintaining genetic integrity, actively participating in various DNA repair processes through its various biochemical activities and via its ability to interact with components of the repair machinery. This report focuses on the impact of the p53 protein on the HIV-1 reverse transcription process while incorporating various incorrect and non-canonical nucleotides. The presence of functional host-coded p53 protein with proofreading-repair activities in the cytoplasm may lead to various biological outcomes.

Long-term persistence of mitochondrial dysfunctions after viral infections and antiviral therapies: A review of mechanisms involved

Mitochondria are vital for most cells' functions. Viruses hijack mitochondria machinery for misappropriation of energy supply or to bypass defense mechanisms. Many of these mitochondrial dysfunctions persist after recovery from treated or untreated viral infections, particularly when mitochondrial DNA is permanently damaged. Quantitative defects and structural rearrangements of mitochondrial DNA accumulate in post-mitotic tissues as recently reported long after SARS-CoV-2 or HIV infection, or following antiviral therapy. These observations are consistent with the "hit-and-run" concept proposed decades ago to explain viro-induced cell transformation and it could apply to delayed post-viral onsets of symptoms and advocate for complementary supportive care. Thus, according to this concept, following exposure to viruses or antiviral agents, mitochondrial damage could evolve into an autonomous clinical condition. It also establishes a pathogenic link between communicable and non-communicable chronic diseases.

Distinct profile of antiviral drugs effects in aortic and pulmonary endothelial cells revealed by high-content microscopy and cell painting assays

Antiretroviral therapy have significantly improved the treatment of viral infections and reduced the associated mortality and morbidity rates. However, highly effective antiretroviral therapy (HAART) may lead to an increased risk of cardiovascular diseases, which could be related to endothelial toxicity. Here, seven antiviral drugs (remdesivir, PF-00835231, ritonavir, lopinavir, efavirenz, zidovudine and abacavir) were characterized against aortic (HAEC) and pulmonary (hLMVEC) endothelial cells, using high-content microscopy. The colourimetric study (MTS test) revealed similar toxicity profiles of all antiviral drugs tested in the concentration range of 1 nM-50 μM in aortic and pulmonary endothelial cells. Conversely, the drugs' effects on morphological parameters were more pronounced in HAECs as compared with hLMVECs. Based on the antiviral drugs' effects on the cytoplasmic and nuclei architecture (analyzed by multiple pre-defined parameters including SER texture and STAR morphology), the studied compounds were classified into five distinct morphological subgroups, each linked to a specific cellular response profile. In relation to morphological subgroup classification, antiviral drugs induced a loss of mitochondrial membrane potential, elevated ROS, changed lipid droplets/lysosomal content, decreased von Willebrand factor expression and micronuclei formation or dysregulated cellular autophagy. In conclusion, based on specific changes in endothelial cytoplasm, nuclei and subcellular morphology, the distinct endothelial response was identified for remdesivir, ritonavir, lopinavir, efavirenz, zidovudine and abacavir treatments. The effects detected in aortic endothelial cells were not detected in pulmonary endothelial cells. Taken together, high-content microscopy has proven to be a robust and informative method for endothelial drug profiling that may prove useful in predicting the organ-specific endothelial toxicity of various drugs.

Pathophysiology and Clinical Management of Dyslipidemia in People Living with HIV: Sailing through Rough Seas

Infections with human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) represent one of the greatest health burdens worldwide. The complex pathophysiological pathways that link highly active antiretroviral therapy (HAART) and HIV infection per se with dyslipidemia make the management of lipid disorders and the subsequent increase in cardiovascular risk essential for the treatment of people living with HIV (PLHIV). Amongst HAART regimens, darunavir and atazanavir, tenofovir disoproxil fumarate, nevirapine, rilpivirine, and especially integrase inhibitors have demonstrated the most favorable lipid profile, emerging as sustainable options in HAART substitution. To this day, statins remain the cornerstone pharmacotherapy for dyslipidemia in PLHIV, although important drug-drug interactions with different HAART agents should be taken into account upon treatment initiation. For those intolerant or not meeting therapeutic goals, the addition of ezetimibe, PCSK9, bempedoic acid, fibrates, or fish oils should also be considered. This review summarizes the current literature on the multifactorial etiology and intricate pathophysiology of hyperlipidemia in PLHIV, with an emphasis on the role of different HAART agents, while also providing valuable insights into potential switching strategies and therapeutic options.

Examining Chronic Inflammation, Immune Metabolism, and T Cell Dysfunction in HIV Infection

Chronic Human Immunodeficiency Virus (HIV) infection remains a significant challenge to global public health. Despite advances in antiretroviral therapy (ART), which has transformed HIV infection from a fatal disease into a manageable chronic condition, a definitive cure remains elusive. One of the key features of HIV infection is chronic immune activation and inflammation, which are strongly associated with, and predictive of, HIV disease progression, even in patients successfully treated with suppressive ART. Chronic inflammation is characterized by persistent inflammation, immune cell metabolic dysregulation, and cellular exhaustion and dysfunction. This review aims to summarize current knowledge of the interplay between chronic inflammation, immune metabolism, and T cell dysfunction in HIV infection, and also discusses the use of humanized mice models to study HIV immune pathogenesis and develop novel therapeutic strategies.

Senescent cells at the crossroads of aging, disease, and tissue homeostasis

Originally identified as an outcome of continuous culture of primary cells, cellular senescence has moved beyond the culture dish and is now a bona fide driver of aging and disease in animal models, and growing links to human disease. This cellular stress response consists of a stable proliferative arrest coupled to multiple phenotypic changes. Perhaps the most important of these is the senescence-associated secretory phenotype, or senescence-associated secretory phenotype -a complex and variable collection of secreted molecules release by senescent cells with a number of potent biological activities. Senescent cells appear in multiple age-associated conditions in humans and mice, and interventions that eliminate these cells can prevent or even reverse multiple diseases in mouse models. Here, we review salient aspects of senescent cells in the context of human disease and homeostasis. Senescent cells increase in abundance during several diseases that associated with premature aging. Conversely, senescent cells have a key role in beneficial processes such as development and wound healing, and thus can help maintain tissue homeostasis. Finally, we speculate on mechanisms by which deleterious aspects of senescent cells might be targeted while retaining homeostatic aspects in order to improve age-related outcomes.

Association of cytokine gene polymorphisms with peripheral neuropathy susceptibility in people living with HIV in Greece

Relatively little research has been done in recent years to understand what leads to the unceasingly high rates of HIV sensory neuropathy despite successful antiretroviral treatment. In vivo and in vitro studies demonstrate neuronal damage induced by HIV and increasingly identified ART neurotoxicity involving mitochondrial dysfunction and innate immune system activation in peripheral nerves, ultimately all pathways resulting in enhanced pro-inflammatory cytokine secretion. Furthermore, many infectious/autoimmune/malignant diseases are influenced by the production-profile of pro-inflammatory and anti-inflammatory cytokines, due to inter-individual allelic polymorphism within cytokine gene regulatory regions. Associations of cytokine gene polymorphisms are investigated with the aim of identifying potential genetic markers for susceptibility to HIV peripheral neuropathy including ART-dependent toxic neuropathy. One hundred seventy-one people living with HIV in Northern Greece, divided into two sub-groups according to the presence/absence of peripheral neuropathy, were studied over a 5-year period. Diagnosis was based on the Brief Peripheral Neuropathy Screening. Cytokine genotyping was performed by sequence-specific primer-polymerase chain reaction. Present study findings identify age as an important risk factor (p < 0.01) and support the idea that cytokine gene polymorphisms are at least involved in HIV peripheral-neuropathy pathogenesis. Specifically, carriers of IL1a-889/rs1800587 TT genotype and IL4-1098/rs2243250 GG genotype disclosed greater relative risk for developing HIV peripheral neuropathy (OR: 2.9 and 7.7 respectively), while conversely, carriers of IL2+166/rs2069763 TT genotype yielded lower probability (OR: 3.1), all however, with marginal statistical significance. The latter, if confirmed in a larger Greek population cohort, may offer in the future novel genetic markers to identify susceptibility, while it remains significant that further ethnicity-oriented studies continue to be conducted in a similar pursuit.

Human immunodeficiency virus and antiretroviral therapy-mediated immune cell metabolic dysregulation in children born to HIV-infected women: potential clinical implications

Commencing lifelong antiretroviral therapy (ART) immediately following HIV diagnosis (Option B+) has dramatically improved the health of HIV-infected women and their children, with the majority being of HIV-exposed children born uninfected (HEU). This success has led to an increasing population of HIV-infected women receiving ART during pregnancy and children exposed to ART in utero. Nonetheless, a small proportion of children are still infected with HIV (HEI) each year. HEI children suffer from reduced immunocompetence and host-defence, due to CD4+ T lymphocyte depletion, but also dysregulation of other immune cells including CD8+ T lymphocytes, natural killer (NK) cells, macrophages including B lymphocytes. Furthermore, although HEU children are uninfected, altered immune responses are observed and associated with increased vulnerability to infections. The mechanisms underlying immune dysregulation in HEU children remain poorly described. Building on early studies, emerging data suggests that HIV/ART exposure early in life affects cell metabolic function of HEU children. Prenatal HIV/ART exposure has been associated with dysregulation of mitochondria, including impaired DNA polymerase activity. Furthermore, dysregulation of oxidative phosphorylation (OXPHOS) causes a decreased generation of adenosine triphosphate (ATP) and increased production of reactive oxygen species (ROS), resulting in oxidative stress. These altered metabolic processes can affect immune cell viability and immune responses. Recent studies have indicated that immune-metabolic dysregulation may contribute to HIV-associated pathogenesis and clinical observations associated with HIV and ART exposure in HEU/HEI children. Given the critical role metabolic processes in immune cell functioning, immune-metabolic dysregulation in HEU and HEI children may have implications in effective host-defence responses against pathogens, as well as efficacy of standard ART regimens and future novel HIV cure approaches in HEI children. At the same time, targeting metabolic pathways of immune cells may provide safer and novel approaches for HIV cure strategies. Here, we review the current literature investigating immune-metabolic dysregulation in paediatric HIV pathogenesis.

HIV Replication Increases the Mitochondrial DNA Content of Plasma Extracellular Vesicles

Extracellular vesicles (EVs) and their cargo have been studied intensively as potential sources of biomarkers in HIV infection; however, their DNA content, particularly the mitochondrial portion (mtDNA), remains largely unexplored. It is well known that human immunodeficiency virus (HIV) infection and prolonged antiretroviral therapy (ART) lead to mitochondrial dysfunction and reduced mtDNA copy in cells and tissues. Moreover, mtDNA is a well-known damage-associated molecular pattern molecule that could potentially contribute to increased immune activation, oxidative stress, and inflammatory response. We investigated the mtDNA content of large and small plasma EVs in persons living with HIV (PLWH) and its implications for viral replication, ART use, and immune status. Venous blood was collected from 196 PLWH, ART-treated or ART-naïve (66 with ongoing viral replication, ≥20 copies/mL), and from 53 HIV-negative persons, all recruited at five HIV testing or treatment centers in Burkina Faso. Large and small plasma EVs were purified and counted, and mtDNA level was measured by RT-qPCR. Regardless of HIV status, mtDNA was more abundant in large than small EVs. It was more abundant in EVs of viremic than aviremic and control participants and tended to be more abundant in participants treated with Tenofovir compared with Zidovudine. When ART treatment was longer than six months and viremia was undetectable, no variation in EV mtDNA content versus CD4 and CD8 count or CD4/CD8 ratio was observed. However, mtDNA in large and small EVs decreased with years of HIV infection and ART. Our results highlight the impact of viral replication and ART on large and small EVs' mtDNA content. The mechanisms underlying the differential incorporation of mtDNA into EVs and their effects on the surrounding cells warrant further investigation.

Immune and Metabolic Alterations in Children with Perinatal HIV Exposure

With the global rollout of mother-to-child prevention programs for women living with HIV, vertical transmission has been all but eliminated in many countries. However, the number of children who are exposed in utero to HIV and antiretroviral therapy (ART) is ever-increasing. These children who are HIV-exposed-but-uninfected (CHEU) are now well recognized as having persistent health disparities compared to children who are HIV-unexposed-and-uninfected (CHUU). Differences reported between these two groups include immune dysfunction and higher levels of inflammation, cognitive and metabolic abnormalities, as well as increased morbidity and mortality in CHEU. The reasons for these disparities remain largely unknown. The present review focuses on a proposed link between immunometabolic aberrations and clinical pathologies observed in the rapidly expanding CHEU population. By drawing attention, firstly, to the significance of the immune and metabolic alterations observed in these children, and secondly, the impact of their healthcare requirements, particularly in low- and middle-income countries, this review aims to sensitize healthcare workers and policymakers about the long-term risks of in utero exposure to HIV and ART.

Dolutegravir-containing HIV therapy reversibly alters mitochondrial health and morphology in cultured human fibroblasts and peripheral blood mononuclear cells

OBJECTIVES

Given the success of combination antiretroviral therapy (cART) in treating HIV viremia, drug toxicity remains an area of interest in HIV research. Despite newer integrase strand transfer inhibitors (InSTIs), such as dolutegravir (DTG) and raltegravir (RAL), having excellent clinical tolerance, there is emerging evidence of off-target effects and toxicities. Although limited in number, recent reports have highlighted the vulnerability of mitochondria to these toxicities. The aim of the present study is to quantify changes in cellular and mitochondrial health following exposure to current cART regimens at pharmacological concentrations. A secondary objective is to determine whether any cART-associated toxicities would be modulated by human telomerase reverse transcriptase (hTERT).

METHODS

We longitudinally evaluated markers of cellular (cell count, apoptosis), and mitochondrial health [mitochondrial reactive oxygen species (mtROS), membrane potential (MMP) and mass (mtMass)] by flow cytometry in WI-38 human fibroblast with differing hTERT expression/localization and peripheral blood mononuclear cells. This was done after 9 days of exposure to, and 6 days following the removal of, seven current cART regimens, including three that contained DTG. Mitochondrial morphology was assessed by florescence microscopy and quantified using a recently developed deep learning-based pipeline.

RESULTS

Exposure to DTG-containing regimens increased apoptosis, mtROS, mtMass, induced fragmented mitochondrial networks compared with non-DTG-containing regimens, including a RAL-based combination. These effects were unmodulated by telomerase expression. All effects were fully reversible following removal of drug pressure.

CONCLUSION

Taken together, our observations indicate that DTG-containing regimens negatively impact cellular and mitochondrial health and may be more toxic to mitochondria, even among the generally well tolerated InSTI-based cART.

Novel Nanotechnology-Based Approaches for Targeting HIV Reservoirs

Highly active anti-retroviral therapy (HAART) is prescribed for HIV infection and, to a certain extent, limits the infection's spread. However, it cannot completely eradicate the latent virus in remote and cellular reservoir areas, and due to the complex nature of the infection, the total eradication of HIV is difficult to achieve. Furthermore, monotherapy and multiple therapies are not of much help. Hence, there is a dire need for novel drug delivery strategies that may improve efficacy, decrease side effects, reduce dosing frequency, and improve patient adherence to therapy. Such a novel strategy could help to target the reservoir sites and eradicate HIV from different biological sanctuaries. In the current review, we have described HIV pathogenesis, the mechanism of HIV replication, and different biological reservoir sites to better understand the underlying mechanisms of HIV spread. Further, the review deliberates on the challenges faced by the current conventional drug delivery systems and introduces some novel drug delivery strategies that have been explored to overcome conventional drug delivery limitations. In addition, the review also summarizes several nanotechnology-based approaches that are being explored to resolve the challenges of HIV treatment by the virtue of delivering a variety of anti-HIV agents, either as combination therapies or by actively targeting HIV reservoir sites.

Mapping Adverse Outcome Pathways for Kidney Injury as a Basis for the Development of Mechanism-Based Animal-Sparing Approaches to Assessment of Nephrotoxicity

In line with recent OECD activities on the use of AOPs in developing Integrated Approaches to Testing and Assessment (IATAs), it is expected that systematic mapping of AOPs leading to systemic toxicity may provide a mechanistic framework for the development and implementation of mechanism-based in vitro endpoints. These may form part of an integrated testing strategy to reduce the need for repeated dose toxicity studies. Focusing on kidney and in particular the proximal tubule epithelium as a key target site of chemical-induced injury, the overall aim of this work is to contribute to building a network of AOPs leading to nephrotoxicity. Current mechanistic understanding of kidney injury initiated by 1) inhibition of mitochondrial DNA polymerase γ (mtDNA Polγ), 2) receptor mediated endocytosis and lysosomal overload, and 3) covalent protein binding, which all present fairly well established, common mechanisms by which certain chemicals or drugs may cause nephrotoxicity, is presented and systematically captured in a formal description of AOPs in line with the OECD AOP development programme and in accordance with the harmonized terminology provided by the Collaborative Adverse Outcome Pathway Wiki. The relative level of confidence in the established AOPs is assessed based on evolved Bradford-Hill weight of evidence considerations of biological plausibility, essentiality and empirical support (temporal and dose-response concordance).

Neuropathy in Human Immunodeficiency Virus: A Review of the Underlying Pathogenesis and Treatment

This article explores the various causes of the human immunodeficiency virus (HIV), and its associated neuropathy, including the effects of HIV on the nervous system and the long-standing therapy that is often provided to patients with HIV. Several studies regarding the neurotoxic effects of combined antiretroviral therapy (cART) and HIV were reviewed and various hypotheses were discussed. Furthermore, we present the nature of HIV-sensory neuropathy (HIV-SN) among different demographic populations and their subsequent risk factors predisposing them to this condition. It was observed that the incidence of the disease increases in increased survival of the patients as well as in males. Finally, the current approach to HIV-SN and its overlapping features with other causes of peripheral neuropathy have been discussed which demonstrates that a clinical examination is the most important clue for a healthcare professional to suspect the disease. Our main aim was to study the current perspectives and guidelines for diagnosing and managing a patient with HIV-SN to reduce disease prevalence and bring about a more aware frame of mind when following up with an HIV patient.

Could very low-calorie ketogenic diets turn off low grade inflammation in obesity? Emerging evidence

Obesity is an emerging non-communicable disease associated with chronic low-grade inflammation and oxidative stress, compounded by the development of many obesity-related diseases, such as cardiovascular disease, type 2 diabetes mellitus, and a range of cancers. Originally developed for the treatment of epilepsy in drug non-responder children, the ketogenic diet (KD) is being increasingly used in the treatment of many diseases, including obesity and obesity-related conditions. The KD is a dietary pattern characterized by high fat intake, moderate to low protein consumption, and very low carbohydrate intake (<50 g) that has proved to be an effective and weight-loss tool. In addition, it also appears to be a dietary intervention capable of improving the inflammatory state and oxidative stress in individuals with obesity by means of several mechanisms. The main activity of the KD has been linked to improving mitochondrial function and decreasing oxidative stress. β-hydroxybutyrate, the most studied ketone body, has been shown to reduce the production of reactive oxygen species, improving mitochondrial respiration. In addition, KDs exert anti-inflammatory activity through several mechanisms, e.g., by inhibiting activation of the nuclear factor kappa-light-chain-enhancer of activated B cells, and the inflammatory nucleotide-binding, leucine-rich-containing family, pyrin domain-containing-3, and inhibiting histone deacetylases. Given the rising interest in the topic, this review looks at the underlying anti-inflammatory and antioxidant mechanisms of KDs and their possible recruitment in the treatment of obesity and obesity-related disorders.

Metabolomics in Placental Tissue from Women Living with HIV

It is unknown whether antiretroviral (ARV) drugs in women living with HIV (WLHIV) are associated with mitochondrial toxicity and altered fat oxidation and branched-chain amino acid metabolism in the placenta and fetus. Immediately after delivery, we froze placental biopsies from 20 WLHIV and 20 matched uninfected women. We analyzed global biochemical profiles using high-performance liquid chromatography/tandem mass spectrometry and gas chromatography/mass spectrometry. We used t-tests, principle component analysis, hierarchical clustering, and random forest analysis (RFA) in our analysis. Twelve WLHIV were on protease inhibitors, six on non-nucleoside reverse inhibitors, and two on integrase strand inhibitors with optimized backbone. Mean birth weight of HIV-exposed neonates was significantly lower than unexposed neonates (3,075 g vs. 3,498 g, p = .01) at similar gestational age. RFA identified 30 of 702 analytes that differentiated the placental profiles of WLHIV from uninfected women with 72.5% predictive accuracy. Placental profiles of non-nucleoside reverse transcriptase inhibitor (NNRTI)-treated WLHIV exhibited lower levels of amino acids, including essential and branched-chain amino acids, and some medium-chain acylcarnitines. Placental metabolism may be altered in WLHIV, possibly associated with ARV exposure. The lower birth weight among neonates of WLHIV suggests the need for further studies considering potential deleterious effects of altered placenta metabolism on fetal growth and development.

Divergent effects of HIV reverse transcriptase inhibitors on pancreatic beta-cell function and survival: Potential role of oxidative stress and mitochondrial dysfunction

Antiretroviral therapy (ART), a life-saving treatment strategy in HIV/AIDS, has been implicated in increasing the risk of type 2 diabetes mellitus (T2DM). Direct damaging effects on beta-cell function and survival by either non-nucleoside reverse transcriptase inhibitors (NNRTIs) or nucleoside/tide reverse transcriptase inhibitors (NRTIs) may predispose individuals to developing T2DM or if already type 2 diabetic, to insulin dependency. The aim of this study was to investigate the effects of the NNRTIs efavirenz, rilpivirine and doravirine, and the NRTIs tenofovir disoproxil fumarate and emtricitabine, on beta-cell function and survival while suggesting potential cellular and molecular mechanism(s). Our results show contrasting effects within the NNRTI class as doravirine did not cause damaging effects in the rat insulinoma INS-1E cells while efavirenz and rilpivirine reduced insulin release and cell viability, and induced apoptosis in INS-1E cells. Additionally, efavirenz and rilpivirine increased ROS generation, disrupted Δψm and upregulated the mRNA and protein expression of CHOP and GRP78, key markers of endoplasmic reticulum stress. In silico docking studies predict a possible inhibition of the mitochondrial ATP synthase by rilpivirine. On the contrary, both the NRTIs tenofovir disoproxil fumarate and emtricitabine did not affect GSIS, cell viability and apoptosis/necrosis levels in INS-1E cells. The deleterious effects observed in beta-cells exposed to efavirenz or rilpivirine may be, at least partially, mediated by oxidative stress and mitochondrial toxicity. These findings provide potential mechanism(s) by which efavirenz and rilpivirine may contribute to the pathogenesis of T2DM and the progression of T2DM to insulin dependency in HIV-infected type 2 diabetics.

Minimum redundancy maximal relevance gene selection of apoptosis pathway genes in peripheral blood mononuclear cells of HIV-infected patients with antiretroviral therapy-associated mitochondrial toxicity

BACKGROUND

We previously identified differentially expressed genes on the basis of false discovery rate adjusted P value using empirical Bayes moderated tests. However, that approach yielded a subset of differentially expressed genes without accounting for redundancy between the selected genes.

METHODS

This study is a secondary analysis of a case-control study of the effect of antiretroviral therapy on apoptosis pathway genes comprising of 16 cases (HIV infected with mitochondrial toxicity) and 16 controls (uninfected). We applied the maximum relevance minimum redundancy (mRMR) algorithm on the genes that were differentially expressed between the cases and controls. The mRMR algorithm iteratively selects features (genes) that are maximally relevant for class prediction and minimally redundant. We implemented several machine learning classifiers and tested the prediction accuracy of the two mRMR genes. We next used network analysis to estimate and visualize the association among the differentially expressed genes. We employed Markov Random Field or undirected network models to identify gene networks related to mitochondrial toxicity. The Spinglass model was used to identify clusters of gene communities.

RESULTS

The mRMR algorithm ranked DFFA and TNFRSF1A, two of the upregulated proapoptotic genes, on the top. The overall prediction accuracy was 86%, the two mRMR genes correctly classified 86% of the participants into their respective groups. The estimated network models showed different patterns of gene networks. In the network of the cases, FASLG was the most central gene. However, instead of FASLG, ABL1 and LTBR had the highest centrality in controls.

CONCLUSION

The mRMR algorithm and network analysis revealed a new correlation of genes associated with mitochondrial toxicity.

Remdesivir induces persistent mitochondrial and structural damage in human induced pluripotent stem cell derived cardiomyocytes

AIMS

Remdesivir is a prodrug of an adenosine triphosphate analogue and is currently the only drug formally approved for the treatment of hospitalised COVID-19 patients. Nucleoside/nucleotide analogues have been shown to induce mitochondrial damage and cardiotoxicity, and this may be exacerbated by hypoxia, which frequently occurs in severe COVID-19 patients. Although there have been few reports of adverse cardiovascular events associated with remdesivir, clinical data are limited. Here, we investigated whether remdesivir induced cardiotoxicity using an in vitro human cardiac model.

METHODS AND RESULTS

Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were exposed to remdesivir under normoxic and hypoxic conditions to simulate mild and severe COVID-19 respectively. Remdesivir induced mitochondrial fragmentation, reduced redox potential and suppressed mitochondrial respiration at levels below the estimated plasma concentration under both normoxic and hypoxic conditions. Non-mitochondrial damage such as electrophysiological alterations and sarcomere disarray were also observed. Importantly, some of these changes persisted after the cessation of treatment, culminating in increased cell death. Mechanistically, we found that inhibition of DRP1, a regulator of mitochondrial fission, ameliorated the cardiotoxic effects of remdesivir, showing that remdesivir-induced cardiotoxicity was preventable and excessive mitochondrial fission might contribute to this phenotype.

CONCLUSIONS

Using an in vitro model, we demonstrated that remdesivir can induce cardiotoxicity in hiPSC-CMs at clinically relevant concentrations. These results reveal previously unknown potential side-effects of remdesivir and highlight the importance of further investigations with in vivo animal models and active clinical monitoring to prevent lasting cardiac damage to patients.

TRANSLATIONAL PERSPECTIVE

Adult cardiomyocytes have limited ability to regenerate, thus treatment-induced cardiotoxicity can potentially cause irreparable harm. Remdesivir is currently the only FDA approved treatment for COVID-19 but clinical safety data are limited. Using human pluripotent stem cell-derived cardiomyocytes, we revealed that remdesivir induced persistent mitochondrial and structural abnormalities at clinically relevant concentrations. We advise confirmatory experiments in in vivo animal models, investigations of cardioprotective strategies, and closer patient monitoring such that treatment-induced cardiotoxicity does not contribute to the long term sequelae of COVID-19 patients.

A Tale of Two Viruses: Immunological Insights Into HCV/HIV Coinfection

Nearly 2.3 million individuals worldwide are coinfected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV). Odds of HCV infection are six times higher in people living with HIV (PLWH) compared to their HIV-negative counterparts, with the highest prevalence among people who inject drugs (PWID) and men who have sex with men (MSM). HIV coinfection has a detrimental impact on the natural history of HCV, including higher rates of HCV persistence following acute infection, higher viral loads, and accelerated progression of liver fibrosis and development of end-stage liver disease compared to HCV monoinfection. Similarly, it has been reported that HCV coinfection impacts HIV disease progression in PLWH receiving anti-retroviral therapies (ART) where HCV coinfection negatively affects the homeostasis of CD4⁺ T cell counts and facilitates HIV replication and viral reservoir persistence. While ART does not cure HIV, direct acting antivirals (DAA) can now achieve HCV cure in nearly 95% of coinfected individuals. However, little is known about how HCV cure and the subsequent resolution of liver inflammation influence systemic immune activation, immune reconstitution and the latent HIV reservoir. In this review, we will summarize the current knowledge regarding the pathogenesis of HIV/HCV coinfection, the effects of HCV coinfection on HIV disease progression in the context of ART, the impact of HIV on HCV-associated liver morbidity, and the consequences of DAA-mediated HCV cure on immune reconstitution and HIV reservoir persistence in coinfected patients.

In utero and peripartum antiretroviral exposure as predictor of cognition in 6- to 10-year-old HIV-exposed Ugandan children - a prospective cohort study

OBJECTIVES

To quantify association between in utero/peripartum antiretroviral (IPA) exposure and cognition, i.e. executive function (EF) and socioemotional adjustment (SEA), in school-aged Ugandan children who were perinatally HIV-infected (CPHIV, n = 100) and children who were HIV-exposed but uninfected (CHEU, n = 101).

METHODS

Children were enrolled at age 6-10 years and followed for 12 months from March 2017 to December 2018. Caregiver-reported child EF and SEA competencies were assessed using validated questionnaires at baseline, 6 and 12 months. IPA type - combination antiretroviral therapy (cART), intrapartum single-dose nevirapine ± zidovudine (sdNVP ± ZDV), nevirapine + zidovudine + lamivudine (sdNVP + ZDV + 3TC) - or no IPA (reference) was verified via medical records. IPA-related standardized mean differences (SMDs) with corresponding 95% confidence intervals (CIs) in cognitive competencies were estimated from regression models with adjustment for caregiver sociodemographic and contextual factors. Models were fitted separately for CPHIV and CHEU.

RESULTS

Among CPHIV children, cART (SMD = -0.82, 95% CI: -1.37 to -0.28) and sdNVP ± ZDV (SMD = -0.41, 95% CI: -0.81 to -0.00) vs. no IPA predicted lower executive dysfunction over 12 months. Intrapartum sdNVP + ZDV + 3TC vs. no IPA predicted executive dysfunction (SMD = 0.80, 95% CI: 0.30-1.31), SEA problems (SMD = 0.63-0.76, 95% CI: 0.00-1.24) and lower adaptive skills (SMD = -0.36, 95% CI: -0.75-0.02) over 12 months among CHEU. Further adjustment for contextual factors attenuated associations, although most remained of moderate clinical importance (|SMD| > 0.33).

CONCLUSIONS

Among CPHIV children, cART and sdNVP ± ZDV IPA exposure predicted, on average, lower executive dysfunction 6-10 years later. However, peripartum sdNVP + ZDV + 3TC predicted executive and SEA dysfunction among CHEU 6-10 years later. These data underscore the need for more research into long-term effects of in utero ART to inform development of appropriate interventions so as to mitigate cognitive sequelae.

Transcriptional and Immunologic Correlates of Response to Pandemic Influenza Vaccine in Aviremic, HIV-Infected Children

People living with HIV (PWH) often exhibit poor responses to influenza vaccination despite effective combination anti-retroviral (ART) mediated viral suppression. There exists a paucity of data in identifying immune correlates of influenza vaccine response in context of HIV infection that would be useful in improving its efficacy in PWH, especially in younger individuals. Transcriptomic data were obtained by microarray from whole blood isolated from aviremic pediatric and adolescent HIV-infected individuals (4-25 yrs) given two doses of Novartis/H1N1 09 vaccine during the pandemic H1N1 influenza outbreak. Supervised clustering and gene set enrichment identified contrasts between individuals exhibiting high and low antibody responses to vaccination. High responders exhibited hemagglutination inhibition antibody titers >1:40 post-first dose and 4-fold increase over baseline. Baseline molecular profiles indicated increased gene expression in metabolic stress pathways in low responders compared to high responders. Inflammation-related and interferon-inducible gene expression pathways were higher in low responders 3 wks post-vaccination. The broad age range and developmental stage of participants in this study prompted additional analysis by age group (e.g. <13yrs and ≥13yrs). This analysis revealed differential enrichment of gene pathways before and after vaccination in the two age groups. Notably, CXCR5, a homing marker expressed on T follicular helper (Tfh) cells, was enriched in high responders (>13yrs) following vaccination which was accompanied by peripheral Tfh expansion. Our results comprise a valuable resource of immune correlates of vaccine response to pandemic influenza in HIV infected children that may be used to identify favorable targets for improved vaccine design in different age groups.

Effects of combination antiretroviral drugs (cART) on hippocampal neuroplasticity in female mice

The incidence of HIV-associated neurocognitive disorder (HAND) continues despite the introduction of combination antiretroviral drugs (cART). Several studies have reported the neurotoxicity of individual antiretroviral drugs (monotherapy), while the common approach for HIV treatment is through cART. Hence, the current study investigated the effects of long-term exposure to cART on cognitive function, oxidative damage, autophagy, and neuroplasticity in the hippocampus of mice. Female Balb/c mice received a once-a-day oral dose of cART composed of emtricitabine + tenofovir disoproxil fumarate or vehicle for 8 weeks. On week 7 of drug administration, all mice were assessed for spatial learning in the Morris water maze (MWM), and then on week 8, mice were sacrificed, and hippocampal tissue dissected from the brain. For biochemical analyses, we measured the concentration of 4-hydroxynonenal, and the expression of autophagic marker LC3B, synaptophysin, and brain-derived neurotrophic factor (BDNF) in the hippocampus. Our results showed that cART exposure increased escape latency in the MWM test. The cART-treated mice also showed increased 4-hydroxynonenal concentration and expression of LC3B. Furthermore, cART treatment decreased the expression of synaptophysin and BDNF. These findings further support the evidence that cART may be neurotoxic and therefore may play a role in the neuropathogenesis of HAND.

Probing the Interface of HIV and Inflammaging

PURPOSE OF REVIEW

Systemic inflammation increases as a consequence of aging (inflammaging) and contributes to age-related morbidities. Inflammation in people living with HIV is elevated compared with the general population even after prolonged suppression of viremia with anti-retroviral therapy. Mechanisms that contribute to inflammation during aging and in treated HIV disease are potentially interactive, leading to an exaggerated inflammatory phenotype in people with HIV.

RECENT FINDINGS

Recent studies highlight roles for anti-retroviral therapy, co-infections, immune system alterations, and microbiome perturbations as important contributors to HIV-associated inflammation. These factors likely contribute to increased risk of age-related morbidities in people living with HIV. Understanding mechanisms that exaggerate the inflammaging process in people with HIV may lead to improved intervention strategies, ultimately, extending both lifespan and healthspan.

HIV Infection and Related Mental Disorders

Over the more than thirty-year period of the human immunodeficiency virus type 1 (HIV-1) epidemic, many data have been accumulated indicating that HIV infection predisposes one to the development of mental pathologies. It has been proven that cognitive disorders in HIV-positive individuals are the result of the direct exposure of the virus to central nervous system (CNS) cells. The use of antiretroviral therapy has significantly reduced the number of cases of mental disorders among people infected with HIV. However, the incidence of moderate to mild cognitive impairment at all stages of HIV infection is still quite high. This review describes the most common forms of mental pathology that occur in people living with HIV and presents the current concepts on the possible pathogenetic mechanisms of the influence of human immunodeficiency virus (HIV-1) and its viral proteins on the cells of the CNS and the CNS’s functions. This review also provides the current state of knowledge on the impact of the antiretroviral therapy on the development of mental pathologies in people living with HIV, as well as current knowledge on the interactions between antiretroviral and psychotropic drugs that occur under their simultaneous administration.

The Impact of HIV- and ART-Induced Mitochondrial Dysfunction in Cellular Senescence and Aging

According to the WHO, 38 million individuals were living with human immunodeficiency virus (HIV), 25.4 million of which were using antiretroviral therapy (ART) at the end of 2019. Despite ART-mediated suppression of viral replication, ART is not a cure and is associated with viral persistence, residual inflammation, and metabolic disturbances. Indeed, due to the presence of viral reservoirs, lifelong ART therapy is required to control viremia and prevent disease progression into acquired immune deficiency syndrome (AIDS). Successful ART treatment allows people living with HIV (PLHIV) to achieve a similar life expectancy to uninfected individuals. However, recent studies have illustrated the presence of increased comorbidities, such as accelerated, premature immune aging, in ART-controlled PLHIV compared to uninfected individuals. Studies suggest that both HIV-infection and ART-treatment lead to mitochondrial dysfunction, ultimately resulting in cellular exhaustion, senescence, and apoptosis. Since mitochondria are essential cellular organelles for energy homeostasis and cellular metabolism, their compromise leads to decreased oxidative phosphorylation (OXPHOS), ATP synthesis, gluconeogenesis, and beta-oxidation, abnormal cell homeostasis, increased oxidative stress, depolarization of the mitochondrial membrane potential, and upregulation of mitochondrial DNA mutations and cellular apoptosis. The progressive mitochondrial damage induced by HIV-infection and ART-treatment likely contributes to accelerated aging, senescence, and cellular dysfunction in PLHIV. This review discusses the connections between mitochondrial compromise and cellular dysfunction associated with HIV- and ART-induced toxicities, providing new insights into how HIV and current ART directly impact mitochondrial functions and contribute to cellular senescence and aging in PLHIV. Identifying this nexus and potential mechanisms may be beneficial in developing improved therapeutics for treating PLHIV.

Symptoms of Toxicity and Plasma Cytochrome c Levels in Human Immunodeficiency Virus-infected Patients Receiving Anti-retroviral Therapy in Ghana: A Cross-sectional Study

BACKGROUND

Side effects and toxicity have posed a threat to the positive contribution of Antiretroviral Therapy (ART) in the management of human immunodeficiency virus (HIV) infection and Acquired Immune Deficiency Syndrome (AIDS). Symptoms of mitochondrial toxicity including myopathy, pancreatitis, hyperlipidaemia and lactic acidosis are found among HIVinfected patients on ART. To date, there is not a reliable biomarker for monitoring ART-related mitochondrial toxicity. Plasma level of Cytochrome c (Cyt-c) has been proposed as a potential biomarker for ART-related toxicity due to its strong association with apoptosis.

OBJECTIVE

The present study assessed toxicity and level of plasma Cyt-c among HIV-infected patients receiving ART in Ghana.

METHODS

A total of eighty (80) HIV patients were recruited into the study. Demographic data were obtained from personal interview and medical records. Plasma samples were screened for toxicity from sixty (60) participants due to limited resources, and plasma Cyt-c levels were determined using ELISA. Data were analyzed using Stata version 13.

RESULTS

Out of the 60 participants, 11 (18.3%) were found with symptoms of myopathy, 12 (20%) with pancreatitis, 21 (35%) with hyperlipidaemia and 36 (60%) with at least one of the symptoms. The concentration of plasma Cyt-c was higher (0.122 ng/ml) in patients with toxicity than in those without toxicity (0.05 ng/ml), though the difference was not statistically significant (p = 0.148). There was a weak correlation between plasma Cyt-c level and duration of ART (Spearman rho = 0.02, p = 0.89).

CONCLUSION

This study, therefore, demonstrated a high prevalence of ART-related toxicity and high levels of Cyt-c in HIV-infected patients in support of the argument that plasma Cyt-c levels are potential biomarkers for determining ART-related toxicity in HIV patients.

Anti-HIV drugs promote β-amyloid deposition and impair learning and memory in BALB/c mice

OBJECTIVES

Growing evidence suggested that antiretroviral (ARV) drugs may promote amyloid beta (Aβ) accumulation in HIV-1-infected brain and the persistence of HIV-associated neurocognitive disorders (HANDs). It has also been shown that lipid peroxidation upregulates β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1) expression and subsequently promotes Aβ peptide production. In the present study, we examined whether chronic exposure to the anti-HIV drugs tenofovir disoproxil fumarate (TDF) and nevirapine induces lipid peroxidation thereby promoting BACE1 and Aβ generation and consequently impair cognitive function in mice.

METHODS

TDF or nevirapine was orally administered to female BALB/c mice once a day for 8 weeks. On the 7th week of treatment, spatial learning and memory were assessed using the Morris water maze test. The levels of lipid peroxidation, BACE1, amyloid β 1-42 (Aβ1-42) and Aβ deposits were measured in the hippocampal tissue upon completion of treatment.

RESULTS

Chronic administration of nevirapine induced spatial learning and memory impairment in the Morris water maze test, whereas TDF did not have an effect. TDF and nevirapine administration increased hippocampal lipid peroxidation and Aβ1-42 concentration. Nevirapine further upregulated BACE1 expression and Aβ deposits.

CONCLUSION

Our results suggest that chronic exposure to TDF and nevirapine contributes to hippocampal lipid peroxidation and Aβ accumulation, respectively, as well as spatial learning and memory deficits in mice even in the absence of HIV infection. These findings further support a possible link between ARV drug toxicity, Aβ accumulation and the persistence of HANDs.

The Role of Oxidative Stress in Physiopathology and Pharmacological Treatment with Pro- and Antioxidant Properties in Chronic Diseases

Oxidative stress (OS) has the ability to damage different molecules and cellular structures, altering the correct function of organs and systems. OS accumulates in the body by endogenous and exogenous mechanisms. Increasing evidence points to the involvement of OS in the physiopathology of various chronic diseases that require prolonged periods of pharmacological treatment. Long-term treatments may contribute to changes in systemic OS. In this review, we discuss the involvement of OS in the pathological mechanisms of some chronic diseases, the pro- or antioxidant effects of their pharmacological treatments, and possible adjuvant antioxidant alternatives. Diseases such as high blood pressure, arteriosclerosis, and diabetes mellitus contribute to the increased risk of cardiovascular disease. Antihypertensive, lipid-lowering, and hypoglycemic treatments help reduce the risk with an additional antioxidant benefit. Treatment with methotrexate in autoimmune systemic inflammatory diseases, such as rheumatoid arthritis, has a dual role in stimulating the production of OS and producing mitochondrial dysfunction. However, it can also help indirectly decrease the systemic OS induced by inflammation. Medicaments used to treat neurodegenerative diseases tend to decrease the mechanisms related to the production of reactive oxygen species (ROS) and balance OS. On the other hand, immunosuppressive treatments used in cancer or human immunodeficiency virus infection increase the production of ROS, causing significant oxidative damage in different organs and systems without widely documented exogenous antioxidant administration alternatives.

Elevated Blood Mitochondrial DNA in Early Life Among Uninfected Children Exposed to Human Immunodeficiency Virus and Combination Antiretroviral Therapy in utero

BACKGROUND

Combination antiretroviral therapy (cART) during pregnancy prevents vertical transmission, but many antiretrovirals cross the placenta and several can affect mitochondria. Exposure to maternal human immunodeficiency virus (HIV) and/or cART could have long-term effects on children who are HIV exposed and uninfected (CHEU). Our objective was to compare blood mitochondrial DNA (mtDNA) content in CHEU and children who are HIV unexposed and uninfected (CHUU), at birth and in early life.

METHODS

Whole-blood mtDNA content at birth and in early life (age 0-3 years) was compared cross-sectionally between CHEU and CHUU. Longitudinal changes in mtDNA content among CHEU was also evaluated.

RESULTS

At birth, CHEU status and younger gestational age were associated with higher mtDNA content. These remained independently associated with mtDNA content in multivariable analyses, whether considering all infants, or only those born at term. Longitudinally, CHEU mtDNA levels remained unchanged during the first 6 months of life, and gradually declined thereafter. A separate age- and sex-matched cross-sectional analysis (in 214 CHEU and 214 CHUU) illustrates that the difference in mtDNA between the groups remains detectable throughout the first 3 years of life.

CONCLUSION

The persistently elevated blood mtDNA content observed among CHEU represents a long-term effect, possibly resulting from in utero stresses related to maternal HIV and/or cART. The clinical impact of altered mtDNA levels is unclear.

Massive release of CD9+ microvesicles in HIV infection, regardless of virologic control

Background

The role of extracellular vesicles (EVs) in human immunodeficiency virus (HIV) pathogenesis is unknown. We examine the cellular origin of plasma microvesicles (MVs), a type of ectocytosis-derived EV, the presence of mitochondria in MVs, and their relationship to circulating cell-free mitochondrial deoxyribonucleic acid (ccf-mtDNA) in HIV-infected patients and controls.

Methods

Five participant groups were defined: 30 antiretroviral therapy (ART)-naive; 30 ART-treated with nondetectable viremia; 30 elite controllers; 30 viremic controllers; and 30 HIV-uninfected controls. Microvesicles were quantified and characterized from plasma samples by flow cytometry. MitoTrackerDeepRed identified MVs containing mitochondria and ccf-mtDNA was quantified by real-time polymerase chain reaction.

Results

Microvesicle numbers were expanded at least 10-fold in all HIV-infected groups compared with controls. More than 79% were platelet-derived MVs. Proportions of MVs containing mitochondria (22.3% vs 41.6%) and MV mitochondrial density (706 vs 1346) were significantly lower among HIV-infected subjects than controls, lowest levels for those on ART. Microvesicle numbers correlated with ccf-mtDNA levels that were higher among HIV-infected patients.

Conclusions

A massive release of platelet-derived MVs occurs during HIV infection. Some MVs contain mitochondria, but their proportion and mitochondrial densities were lower in HIV infection than in controls. Platelet-derived MVs may be biomarkers of platelet activation, possibly reflecting pathogenesis even in absence of HIV replication.

Association Between HIV Infection and Mitochondrial DNA Copy Number in Peripheral Blood: A Population-Based, Prospective Cohort Study

BACKGROUND

Low mitochondrial DNA (mtDNA) copy number (CN) is a predictor of adverse aging outcomes, and its status may be altered in human immunodeficiency virus (HIV)-infected persons. This study evaluated the cross-sectional and longitudinal change of mtDNA CN by HIV markers.

METHODS

mtDNA CN was measured in the ALIVE (AIDS Linked to the Intravenous Experience) cohort of persons with a history of injecting drugs. Multivariable linear regression models controlling for demographic characteristics, behavior, and hepatitis C virus (HCV) seropositivity assessed the relationship of mtDNA CN to HIV markers (CD4+ T-cell counts, viral load, antiretroviral therapy [ART] use). Linear mixed models tested the association between HIV markers and age-related mtDNA CN trajectories.

RESULTS

Among 741 individuals at baseline, 436 (59%) were infected with HIV. HIV-infected individuals who had lower CD4+ T-cell counts (P = .01), had higher viral loads (P < .01), and were not receiving ART (P < .01) had significantly lower mtDNA CNs than uninfected persons; there was no difference between participants who were uninfected and HIV-infected individuals who had well-controlled HIV levels. In longitudinal follow-up of 507 participants, from age 50 years onward, mtDNA CN declined significantly faster among HIV-infected individuals than among HIV-uninfected persons (-0.03 units of change/year vs 0.006 units of change/year; P = .04), even among infected individuals with well-controlled HIV.

CONCLUSION

Before 50 years of age, mtDNA CN is similar between HIV-infected individuals with well-controlled HIV and uninfected persons, but from age 50 onward, mtDNA CN declines significantly faster among all infected individuals than among HIV-uninfected persons.

Mitochondrial and Oxidative Impacts of Short and Long-term Administration of HAART on HIV Patients

BACKGROUND

There may be a possible link between the use of HAART and oxidative stress-related mitochondrial dysfunction in HIV patients. We evaluated the mitochondrial and oxidative impacts of short and long-term administration of HAART on HIV patients attending the Enugu State University Teaching (ESUT) Hospital, Enugu, Nigeria following short and long-term therapy.

METHODS

96 patients categorized into four groups of 24 individuals were recruited for the study. Group 1 comprised of age-matched, apparently healthy, sero-negative individuals (the No HIV group); group 2 consisted of HIV sero-positive individuals who had not started any form of treatment (the Treatment naïve group). Individuals in group 3 were known HIV patients on HAART for less than one year (Short-term treatment group), while group 4 comprised of HIV patients on HAART for more than one year (Long-term treatment group). All patients were aged between 18 to 60 years and attended the HIV clinic at the time of the study. Determination of total antioxidant status (TAS in nmol/l), malondialdehyde (MDA in mmol/l), CD4+ count in cells/μl, and genomic studies were all done using standard operative procedures.

RESULTS

We found that the long-term treatment group had significantly raised the levels of MDA, as well as significantly diminished TAS compared to the Short-term treatment and No HIV groups (P<0.05). In addition, there was significantly elevated variation in the copy number of mitochondrial genes (mtDNA: D-loop, ATPase 8, TRNALEU uur) in the long-term treatment group.

CONCLUSION

Long-term treatment with HAART increases oxidative stress and causes mitochondrial alterations in HIV patients.

Subcutaneous Adipocyte Adenosine Triphosphate Levels in HIV Infected Patients

Lipoatrophy, or fat wasting, remains a syndrome plaguing HIV⁺ patients receiving antiretroviral (ARV) therapy. Both HIV infection per se and certain ARV are associated with lowered adipose tissue mitochondrial deoxyribonucleic acid (mtDNA) and mitochondrial ribonucleic acid (mtRNA) levels, but effects on adenosine triphosphate (ATP) production are unclear. We hypothesized that such alterations would accompany lowering of ATP levels in fat of HIV⁺ patients and would be worse in those displaying lipoatrophy. Gluteal-fold, subcutaneous adipose tissue was obtained from HIV seronegative control patients, from HIV⁺ ARV-naive patients, and those on ARV with or without lipoatrophy. Cellular ATP was measured in isolated adipocytes and preadipocyte fraction cells by bioluminescence. mtDNA copies/cell and oxidative phosphorylation (OXPHOS) mtRNA transcripts were evaluated by quantitative polymerase chain reactions. ATP levels were consistently higher in preadipocyte fraction cells than adipocytes, but values strongly correlated with each other (r = 0.66, p < .001). ATP levels in adipocytes were higher in both ARV-naive and nonlipoatrophic HIV⁺ patients compared to seronegative controls, but significantly lower in adipocytes and preadipocytes of lipoatrophic versus other HIV⁺ patients. Fat mtDNA copies/cell and OXPHOS mtRNA transcripts were lower in lipoatrophic patient samples compared to HIV seronegative. The ratio of specific OXPHOS transcripts to each other was significantly higher in nonlipoatrophic patients versus all groups, and this ratio correlated significantly with ATP levels in adipocytes. Thus, HIV infection is associated with an increase in adipose tissue ATP stores. Decreases in adipose mtDNA and OXPHOS mtRNA are found in those with HIV on ARV; however, ATP level is effected only in patients displaying lipoatrophy.

Nonalcoholic fatty liver disease and steatohepatitis in people living with HIV

Introduction: The burden of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) is increasing worldwide. This phenomenon poses a potentially dangerous risk of rise in mortalities caused by cirrhosis and liver cancer. Owing to a complex combination of factors, NAFLD and NASH arise in a majority of people living with HIV (PLWH), but accurate estimates of prevalence differ, depending on sample selection, type of analysis, and data interpretation. The wide range of diagnostic tools used to assess liver steatosis and lack of control groups in many studies further contributes to current difficulties in properly assessing prevalence of these conditions. Areas covered: Thoroughly scrutinizing the current literature, we compared the prevalence of NAFLD and NASH in PLWH to rates found in the general population. We highlighted strengths and limitations of the studies, in order to determine the effective impact of these medical conditions in PLWH. Expert opinion: The prevalence and progression of NAFLD in human immunodeficiency virus (HIV) infection are reported to be widely variable. HIV infection itself and antiretroviral treatment have been demonstrated to play a role in the development of NAFLD. Larger and more effective studies are needed to evaluate the effects of NASH in PLWH and its progression.

DNA polymerase-γ hypothesis in nucleoside reverse transcriptase-induced mitochondrial toxicity revisited: A potentially protective role for citrus fruit-derived naringenin?

Nucleoside reverse transcriptase inhibitors (NRTIs) form the backbone in combination antiretroviral therapy (cARVs). They halt chain elongation of the viral cDNA by acting as false substrates in counterfeit incorporation mechanism to viral RNA-dependent DNA polymerase. In the process genomic DNA polymerase as well as mitochondrial DNA (mtDNA) polymerase-γ (which has a much higher affinity for these drugs at therapeutic doses) are also impaired. This leads to mitochondrial toxicity that manifests clinically as mitochondrial myopathy, peripheral neuropathy, hyperlactatemia or lactic acidosis and lipoatrophy. This has led to the revision of clinical guidelines by World Health Organization to remove stavudine from first-line listing in the treatment of HIV infections. Recent reports have implicated oxidative stress besides mtDNA polymerase-γ hypothesis in NRTI-induced metabolic complications. Reduced plasma antioxidant concentrations have been reported in HIV positive patients on cARVs but clinical intervention with antioxidant supplements have not been successful either due to low efficacy or poor experimental designs. Citrus fruit-derived naringenin has previously been demonstrated to possess antioxidant and free radical scavenging properties which could prevent mitochondrial toxicity associated with these drugs. This review revisits the controversy surrounding mtDNA polymerase-γ hypothesis and evaluates the potential benefits of naringenin as a potent anti-oxidant and free radical scavenger which as a nutritional supplement or therapeutic adjunct could mitigate the development of mitochondrial toxicity associated with these drugs.

Mitochondrial Haplogroups N9 and G Are Associated with Metabolic Syndrome Among Human Immunodeficiency Virus-Infected Patients in China

Increasing evidence shows that mitochondrial DNA (mtDNA) variations have an important effect on metabolic disorders, but such studies have not been conducted in HIV-infected patients in Asia. We investigated the distribution of mtDNA haplogroups and their correlation with metabolic disorders in HIV-infected patients. A cross-sectional survey was performed among 296 HIV patients older than the age of 40 years in a rural prefecture, Eastern China. The entire mtDNA sequence was amplified by polymerase chain reaction using four overlapping pairs of primers that have been standardly used. In this sample, mtDNA haplogroups B, D, M7, and F were the most dominant haplogroups. The overall prevalence of metabolic syndrome (MetS) was 36.1%, and was highest (77.8%) among those with haplogroup G and lowest (21.4%) among those with haplogroup M8. In multivariable analysis, haplogroups G and N9 were significantly associated with the presence of MetS [adjusted odds ratio (aOR) = 13.5, 95% confidence interval (CI): 1.9-94.7; aOR = 8.1, 95% CI: 1.8-36.1; respectively]. Moreover, patients with haplogroup G had increased odds of elevated glycated hemoglobin (HbA1c) (aOR = 10.1, 95% CI: 1.4-71.1), patients with haplogroup N9 had increased odds of elevated triglycerides (aOR = 13.5, 95% CI: 2.4-76.8). No significant association between mtDNA haplogroups and other MetS components was observed. Our data demonstrate the association between mtDNA haplogroups and MetS in HIV-infected patients. The Asian-specific mtDNA haplogroups G and N9 may confer higher risk for the development of MetS in HIV-infected patients, which requires further longitudinal investigation.

Examining Relationships between Metabolism and Persistent Inflammation in HIV Patients on Antiretroviral Therapy

With the advent of antiretroviral therapy (ART), HIV-infected individuals are now living longer and healthier lives. However, ART does not completely restore health and treated individuals are experiencing increased rates of noncommunicable diseases such as dyslipidemia, insulin resistance, type 2 diabetes, cardiovascular disease, and nonalcoholic fatty liver disease. While it is well known that persistent immune activation and inflammation contribute to the development of these comorbid diseases, the mechanisms underlying this chronic activation remain incompletely understood. In this review, we will discuss emerging evidence that suggests that alterations in cellular metabolism may play a central role in driving this immune dysfunction in HIV patients on ART.

Combination of Tenofovir and Emtricitabine with Efavirenz Does Not Moderate Inhibitory Effect of Efavirenz on Mitochondrial Function and Cholesterol Biosynthesis in Human T Lymphoblastoid Cell Line

Efavirenz (EFV), the most popular nonnucleoside reverse transcriptase inhibitor, has been associated with mitochondrial dysfunction in most in vitro studies. However, in real life the prevalence of EFV-induced mitochondrial toxicity is relatively low. We hypothesized that the agents given in combination with EFV moderate the effect of EFV on mitochondrial function. To test this hypothesis, we cultured a human T lymphoblastoid cell line (CEM cells) with EFV alone and in combination with emtricitabine (FTC) and tenofovir disoproxil fumarate (TDF) to investigate the effects on mitochondrial respiration and function and cholesterol biosynthesis. There was a statistically significant concentration- and time-dependent apoptosis, reduction in mitochondrial membrane potential, and increase in production of reactive oxygen species in cells treated with either EVF alone or in combination with TDF plus FTC. Compared to dimethyl sulfoxide-treated cells, EFV-treated cells had significant reduction in oxygen consumption rate contributed by basal mitochondrial respiration and decreased protein expression of electron transport chain complexes (CI, CII, and CIV). Treatment with EFV resulted in a decrease in mitochondrial DNA content and perturbation of more coding genes (n = 13); among these were 11 genes associated with lipid or cholesterol biosynthesis. Our findings support the growing body of knowledge on the effects of EFV on mitochondrial respiration and function and cholesterol biosynthesis. Interestingly, combining TDF and FTC with EFV did not alter the effects of EFV on mitochondrial respiration and function and cholesterol biosynthesis. The gap between the prevalence of EFV-induced mitochondrial toxicity in in vitro and in vivo studies could be due to individual differences in the pharmacokinetics of EFV.

Effect of the Anti-retroviral Drugs Efavirenz, Tenofovir and Emtricitabine on Endothelial Cell Function: Role of PARP

Highly active anti-retroviral therapy has proved successful in reducing morbidity and mortality associated with HIV infection though it has been linked to increased risk of cardiovascular disease. To date, the direct effects of the anti-retroviral drugs Efavirenz, Tenofovir and Emtricitabine on the vasculature relaxant response have not been elucidated, which impaired may predispose individuals to cardiovascular disease. Increased cellular oxidative stress and overactivation of the DNA repair enzyme poly (ADP-ribose) polymerase (PARP) have been identified as central mediators of vascular dysfunction. The aim of this study was to investigate whether exposure to Efavirenz, Tenofovir or Emtricitabine directly causes endothelial cell dysfunction via overactivation of PARP. Exposure of ex vivo male rat aortic rings or in vitro endothelial cells to Efavirenz but not Tenofovir or Emtricitabine impaired the acetylcholine-mediated relaxant response, increased cellular oxidative stress and PARP activity, decreased cell viability and increased apoptosis and necrosis. Pharmacological inhibition of PARP protected against the Efavirenz-mediated impairment of vascular relaxation and endothelial cell dysfunction. Oestrogen exposure also protected against the Efavirenz-mediated inhibition of the vascular relaxant response, cell dysfunction and increased PARP activation. In conclusion, Efavirenz directly impairs endothelial cell function, which may account for the increased risk of developing cardiovascular complications with anti-retroviral therapy.

Changes in Liver Steatosis After Switching From Efavirenz to Raltegravir Among Human Immunodeficiency Virus-Infected Patients With Nonalcoholic Fatty Liver Disease

Background

Antiretroviral drugs with a lower potential to induce hepatic steatosis in human immunodeficiency virus (HIV) infection need to be identified. We compared the effect of switching efavirenz (EFV) to raltegravir (RAL) on hepatic steatosis among HIV-infected patients with nonalcoholic fatty liver disease (NAFLD) receiving EFV plus 2 nucleoside analogues.

Methods

HIV-infected patients on EFV plus tenofovir/emtricitabine or abacavir/lamivudine with NAFLD were randomized 1:1 to switch from EFV to RAL (400 mg twice daily), maintaining nucleoside analogues unchanged, or to continue with EFV plus 2 nucleoside analogues. At baseline, eligible patients should show controlled attenuation parameter (CAP) values ≥238 dB/m. Changes in hepatic steatosis at 48 weeks of follow-up over baseline levels were measured by CAP.

Results

Overall, 39 patients were included, and 19 of them were randomized to switch to RAL. At week 48, median CAP for the RAL group was 250 (Q1-Q3, 221-277) dB/m and 286 (Q1-Q3, 269-314) dB/m for the EFV group (P = .035). The median decrease in CAP values was -20 (Q1-Q3, -67 to 15) dB/m for the RAL arm and 30 (Q1-Q3, -17 to 49) dB/m for the EFV group (P = .011). CAP values <238 dB/m at week 48 were observed in 9 (47%) patients on RAL and 3 (15%) individuals on EFV (P = .029).

Conclusions

After 48 weeks, HIV-infected individuals switching EFV to RAL showed decreases in the degree of hepatic steatosis, as measured by CAP, compared with those continuing with EFV. In addition, the proportion of patients without significant hepatic steatosis after 48 weeks was greater for those who switched to RAL.

Clinical Trials Registration

NCT01900015.

Beyond the polymerase-γ theory: Production of ROS as a mode of NRTI-induced mitochondrial toxicity

Use of some HIV-1 nucleoside reverse transcriptase inhibitors (NRTI) is associated with severe adverse events. However, the exact mechanisms behind their toxicity has not been fully understood. Mitochondrial dysfunction after chronic exposure to specific NRTIs has predominantly been assigned to mitochondrial polymerase-γ inhibition by NRTIs. However, an increasing amount of data suggests that this is not the sole mechanism. Many NRTI induced adverse events have been linked to the incurrence of oxidative stress, although the causality of events leading to reactive oxygen species (ROS) production and their role in toxicity is unclear. In this study we show that short-term effects of first generation NRTIs, which are rarely discussed in the literature, include inhibition of oxygen consumption, decreased ATP levels and increased ROS production. Collectively these events affect fitness and longevity of C. elegans through mitohormetic signalling events. Furthermore, we demonstrate that these effects can be normalized by addition of the anti-oxidant N-acetylcysteine (NAC), which suggests that ROS likely influence the onset and severity of adverse events upon drug exposure.

Adipose Tissue in HIV Infection

HIV infection and antiretroviral therapy (ART) treatment exert diverse effects on adipocytes and stromal-vascular fraction cells, leading to changes in adipose tissue quantity, distribution, and energy storage. A HIV-associated lipodystrophic condition was recognized early in the epidemic, characterized by clinically apparent changes in subcutaneous, visceral, and dorsocervical adipose depots. Underlying these changes is altered adipose tissue morphology and expression of genes central to adipocyte maturation, regulation, metabolism, and cytokine signaling. HIV viral proteins persist in circulation and locally within adipose tissue despite suppression of plasma viremia on ART, and exposure to these proteins impairs preadipocyte maturation and reduces adipocyte expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) and other genes involved in cell regulation. Several early nucleoside reverse transcriptase inhibitor and protease inhibitor antiretroviral drugs demonstrated substantial adipocyte toxicity, including reduced mitochondrial DNA content and respiratory chain enzymes, reduced PPAR-γ and other regulatory gene expression, and increased proinflammatory cytokine production. Newer-generation agents, such as integrase inhibitors, appear to have fewer adverse effects. HIV infection also alters the balance of CD4+ and CD8+ T cells in adipose tissue, with effects on macrophage activation and local inflammation, while the presence of latently infected CD4+ T cells in adipose tissue may constitute a protected viral reservoir. This review provides a synthesis of the literature on how HIV virus, ART treatment, and host characteristics interact to affect adipose tissue distribution, immunology, and contribution to metabolic health, and adipocyte maturation, cellular regulation, and energy storage. © 2017 American Physiological Society. Compr Physiol 7:1339-1357, 2017.

Upregulation of Apoptosis Pathway Genes in Peripheral Blood Mononuclear Cells of HIV-Infected Individuals with Antiretroviral Therapy-Associated Mitochondrial Toxicity

A case-control study of the effect of antiretroviral therapy (ART) on apoptosis pathway genes comprising 16 cases (HIV infected with mitochondrial toxicity) and 16 controls (HIV uninfected) was conducted. A total of 26 of 84 genes of the apoptosis pathway were differentially expressed. Two of the upregulated genes, DFFA and TNFRSF1A, classified 75% of study participants correctly as either a case or control. Thus, apoptosis may be in the causal pathway of ART-associated mitochondrial toxicity. These two genes could be markers for detecting and monitoring ART-induced mitochondrial toxicity.

Distinct Mitochondrial Disturbance in CD4+T and CD8+T Cells From HIV-Infected Patients

BACKGROUND

Mitochondrial dysfunction has frequently been found in HIV-infected patients regardless of whether they received antiretroviral therapy (ART). Accumulating evidence suggests that HIV-infected patients exhibit marked changes in mitochondrial membrane potential (MMP), reactive oxygen species (ROS) accumulation, adenosine triphosphate generation, mitochondrial mass (MM), mitochondrial DNA, etc. However, mitochondrial toxicity in CD4T and CD8T cells caused by different levels of HIV progression and ART is poorly understood.

METHODS

Blood samples were obtained from 97 ART-naïve HIV-infected patients with different CD4T cell counts, 97 nucleoside-reverse transcriptase inhibitors-exposed HIV-infected patients, and 25 HIV-negative subjects. MMP, ROS, and MM in CD4T and CD8T cells were assessed by flow cytometry.

RESULTS

In healthy subjects, the levels of MMP and MM in CD4T cells were higher than those in CD8T cells. HIV infection led to an increase in MM in CD4T and CD8T cells, but mainly influenced MMP in CD8T cells and ROS accumulation in CD4T cells. MM in CD4T and CD8T cells gradually increased after the loss of CD4T cells. Although the dynamic changes in MMP in CD4T cells were different from those in CD8T cells during highly active ART, MM in both CD4T and CD8T cells was significantly decreased after 2 years of therapy, but increased again after 3 years.

CONCLUSIONS

HIV infection and antiretroviral therapy both led to mitochondrial disturbances in CD4T cells and CD8T cells; however, the abnormal changes in mitochondrial parameters in CD4+T cells were different from those in CD8T cells caused by HIV infection and antiretroviral therapy.