Inhibition of mitochondrial function by efavirenz increases lipid content in hepatic cells

Elucidating the effect of drug-induced mitochondrial dysfunction on insulin signaling and glucose handling in skeletal muscle cell line (C2C12) in vitro

Efavirenz, tenofovir, rifampicin, simvastatin, lamotrigine and clarithromycin are known potential mitochondrial toxicants. Mitochondrial toxicity has been reported to disrupt the chain of events in the insulin signalling pathway. Considering the upward trajectory of diabetes mellitus prevalence, studies which seek to uncover probable risk factors for developing diabetes should be encouraged. This study aimed to evaluate the intracellular mechanisms leading to the development of insulin resistance in the presence of various conventional pharmacological agents reported as potential mitochondrial toxicants in skeletal muscle cell line. Differentiated C2C12 preparations were exposed to multiple concentrations of efavirenz, tenofovir, rifampicin, simvastatin, lamotrigine, and clarithromycin, separately. Glucose handling was evaluated by observing the changes in insulin-stimulated glucose uptake and assessing the changes in GLUT4 translocation, GLUT4 expression and Akt expression. The changes in mitochondrial function were evaluated by assessing mitochondrial membrane integrity, cellular ATP production, generation of intracellular reactive oxygen species, expression of tafazzin and quantification of medium malonaldehyde. Insulin stimulated glucose uptake was perturbed in C2C12 pre-treated with potential mitotoxicants. Additionally, ATP synthesis, alterations in mitochondrial membrane potential, excessive accumulation of ROS and malonaldehyde were observed in the presence of potential mitotoxicants. Particularly, we observed suppression of proteins involved in the insulin signalling pathway and maintenance of mitochondrial function namely GLUT4, Akt and tafazzin. Mitochondrial toxicants can potentially induce insulin resistance emanating from mitochondrial dysfunction. These new findings will contribute to the understanding of underlying mechanisms involved in the development of insulin resistance linked to mitochondrial dysfunction.

Hazards of antiviral contamination in water: Dissemination, fate, risk and their impact on fish

Antiviral drugs are a cornerstone in the first line of antiviral therapy and their demand rises consistently with increments in viral infections and successive outbreaks. The drugs enter the waters due to improper disposal methods or via human excreta following their consumption; consequently, many of them are now classified as emerging pollutants. Hereby, we review the global dissemination of these medications throughout different water bodies and thoroughly investigate the associated risk they pose to the aquatic fauna, particularly our vertebrate relative fish, which has great economic and dietary importance and subsequently serves as a major doorway to the human exposome. Our risk assessment identifies eleven such drugs that presently pose high to moderate levels of risk to the fish. The antiviral drugs are likely to induce oxidative stress, alter the behaviour, affect different physiological processes and provoke various toxicological mechanisms. Many of the compounds exhibit elevated bioaccumulation potential, while, some have an increased tendency to leach through soil and contaminate the groundwater. Eight antiviral medications show a highly recalcitrant nature and would impact the aquatic life consistently in the long run and continue to influence the human exposome. Thereby, we call for urgent ecopharmacovigilance measures and modification of current water treatment methods.

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.

Efavirenz: New Hope in Cancer Therapy

Despite extensive research directed at preventive and treatment strategies, breast cancer remains the leading cause of cancer-related mortality among women. This necessitates the development of a new medication aimed at increasing patient survival and quality of life. A new drug's development from the ground up can cost billions of dollars and take up to ten or more years. Because much of the required safety and pharmacokinetic data are already available from earlier trials, repurposing medications usually results in lower costs and shorter turnaround times. Many antiretroviral medications target biological pathways and enzymes associated with cancer, which becomes an ideal option for repurposing as anticancer medications. Efavirenz is an antiretroviral medication that targets molecular pathways implicated in the growth of breast cancer, such as LINE-1 (long interspersed nuclear elements-1) suppression, hence lowering the proliferation of breast cancer cells and exhibiting anti-cancer properties. Additionally, it suppresses the fatty acid synthase gene and other important genes related to fat metabolism, impairing mitochondrial activity and making cancer cells deprived of energy. Efavirenz also inhibits cancer-initiating stem cells, promotes differentiation, and prevents recurrence. Additionally, efavirenz promotes oxidative damage by the formation of superoxide in cancer cells. In addition to its anti-cancer properties, efavirenz has the advantage of being a well-established and relatively inexpensive medication with a favorable safety profile. If proven effective, efavirenz could offer a cost-effective therapeutic option, which is an intriguing direction that warrants further investigation.

Metabolic, Mitochondrial, and Inflammatory Effects of Efavirenz, Emtricitabine, and Tenofovir Disoproxil Fumarate in Asymptomatic Antiretroviral-Naïve People with HIV

This study aimed to comprehensively assess the metabolic, mitochondrial, and inflammatory effects of first-line efavirenz, emtricitabine, and tenofovir disoproxil fumarate (EFV/FTC/TDF) single-tablet regimen (STR) relative to untreated asymptomatic HIV infection. To this end, we analyzed 29 people with HIV (PWH) treated for at least one year with this regimen vs. 33 antiretroviral-naïve PWH. Excellent therapeutic activity was accompanied by significant alterations in metabolic parameters. The treatment group showed increased plasmatic levels of glucose, total cholesterol and its fractions (LDL and HDL), triglycerides, and hepatic enzymes (GGT, ALP); conversely, bilirubin levels (total and indirect fraction) decreased in the treated cohort. Mitochondrial performance was preserved overall and treatment administration even promoted the recovery of mitochondrial DNA (mtDNA) content depleted by the virus, although this was not accompanied by the recovery in some of their encoded proteins (since cytochrome c oxidase II was significantly decreased). Inflammatory profile (TNFα, IL-6), ameliorated after treatment in accordance with viral reduction and the recovery of TNFα levels correlated to mtDNA cell restoration. Thus, although this regimen causes subclinical metabolic alterations, its antiviral and anti-inflammatory properties may be associated with partial improvement in mitochondrial function.

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.

Effects of individual drug and combination antiretroviral therapy on trophoblast proliferation

BACKGROUND

Combination antiretroviral therapy (cART) has been reported to reduce perinatal transmission of human immunodeficiency virus (HIV) and improve maternal survival outcomes. Recent studies have associated in-utero exposure to cART drugs with adverse outcomes such as pre-eclampsia, preterm delivery, low birth weight and small-for-gestational-age births. However, the exact molecular mechanisms underlying cART-induced adverse pregnancy outcomes remain poorly defined.

OBJECTIVES

To investigate the effects of cART drugs on trophoblast proliferation in the HTR-8/SVneo cell line.

STUDY DESIGN

HTR-8/SVneo cells were exposed to tenofovir (0.983-9.83 µM), emtricitabine (0.809-8.09 µM) and efavirenz (0.19-1.09 µM), the individual drugs of the first-line single tablet cART regimen termed 'Atripla', and zidovudine (1.12-1.12 µM), lamivudine (0.65-6.5 µM), lopinavir (0.32-3.2 µM) and ritonavir (0.69-6.9 µM), the individual drugs of the second-line single tablet cART regimen termed 'Aluvia'. The cells were treated for 24, 48, 72 and 96 h, and trophoblast proliferation was assessed using a colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltretrazolium bromide assay.

RESULTS

Two-way analysis of variance showed a significant dose-dependent decrease (p < 0.05) in trophoblast proliferation in response to individual and combined drug components of first- and second-line antiretroviral therapy.

CONCLUSIONS

First- and second-line cART drugs inhibit trophoblast proliferation, and may contribute to placenta-mediated adverse pregnancy outcomes in patients with HIV.

Connection Between HIV and Mitochondria in Cardiovascular Disease and Implications for Treatments

HIV infection and antiretroviral therapy alter mitochondrial function, which can progressively lead to mitochondrial damage and accelerated aging. The interaction between persistent HIV reservoirs and mitochondria may provide insight into the relatively high rates of cardiovascular disease and mortality in persons living with HIV. In this review, we explore the intricate relationship between HIV and mitochondrial function, highlighting the potential for novel therapeutic strategies in the context of cardiovascular diseases. We reflect on mitochondrial dynamics, mitochondrial DNA, and mitochondrial antiviral signaling protein in the context of HIV. Furthermore, we summarize how toxicities related to early antiretroviral therapy and current highly active antiretroviral therapy can contribute to mitochondrial dysregulation, chronic inflammation, and poor clinical outcomes. There is a need to understand the mechanisms and develop new targeted therapies. We further consider current and potential future therapies for HIV and their interplay with mitochondria. We reflect on the next-generation antiretroviral therapies and HIV cure due to the direct and indirect effects of HIV persistence, associated comorbidities, coinfections, and the advancement of interdisciplinary research fields. This includes exploring novel and creative approaches to target mitochondria for therapeutic intervention.

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.

Prevalence and risk factors of metabolic syndrome in Ethiopia: describing an emerging outbreak in HIV clinics of the sub-Saharan Africa - a cross-sectional study

OBJECTIVES

HIV-induced chronic inflammation, immune activation and combination antiretroviral therapy (cART) are linked with adverse metabolic changes known to cause cardiovascular adversities. This study evaluates the prevalence of lipodystrophy, and metabolic syndrome (MetS), and analyses risk factors in HIV-infected Ethiopians taking cART.

METHODS

A multicentre cross-sectional study was conducted at tertiary-level hospitals. Eligible participants attending the HIV clinics were enrolled. Sociodemographic, anthropometric, clinical, HIV treatment variables, lipid profile, fasting blood glucose level, risk factors and components of MetS, also lipodystrophy, were studied. Data were analysed by SPSS statistical package V.25 with descriptive and analytical statistics. For multivariable analysis of risk factors, a logistic regression model was used. Results were presented in frequency and percentages, mean±SD, or median+IQR. Statistical significance was taken as p<0.05.

RESULTS

Among 518 studied participants, two-thirds were females, and the mean age of the study population was 45 years (SD=11). The mean duration of cART was 10 years (SD=4). Median CD4 count was 460 cells/mm3. The prevalence of MetS according to the Adult Treatment Panel III (2005) criteria was 37.6%. In multivariable analysis, independent risk factors for MetS were age >45 years (aHR 1.8, 95% CI 1.2 to 2.4), female sex (aHR 1.8, 95% CI 1.1 to 2.8), body mass index (BMI)>25 kg/m2 (aHR 2.7, 95% CI 1.8 to 4.1), efavirenz-based cART (aHR 2.8, 95% CI 1.6 to 4.8) and lopinavir/ritonavir-based cART (aHR 3.7, 95% CI 1.0 to 13.3). The prevalence of lipodystrophy was 23.6%. Prior exposure to a stavudine-containing regimen was independently associated with lipodystrophy (aHR 3.1, 95% CI 1.6 to 6.1).

CONCLUSION

Our study revealed 38% of the participants had MetS indicating considerable cardiovascular disease (CVD) risks. Independent risk factors for MetS were BMI≥25 kg/m2, efavirenz and lopinavir/ritonavir-based cART, female sex and age ≥45 years. In addition to prevention, CVD risk stratification and management will reduce morbidity and mortality in people with HIV infection.

Associations of HIV and antiretroviral therapy with gestational diabetes in South Africa

OBJECTIVE

To estimate associations of HIV status and antiretroviral (ART) regimen with gestational diabetes (GDM) and postpartum glucose metabolism.

DESIGN

Prospective cohort study.

METHODS

We enrolled pregnant persons with HIV (PWH) and without HIV in Cape Town, South Africa who were at least 18 years of age at 24-28 weeks' gestation and followed up to 26 months postpartum. Participants were tested for GDM in pregnancy and for diabetes postpartum using a 75 g 2 h oral glucose tolerance test (OGTT) and diagnosed via WHO criteria. We estimated associations of HIV status and ART regime [efavirenz (EFV) versus dolutegravir (DTG)] with GDM and postpartum impaired glucose metabolism using multivariable log binomial or linear regression models.

RESULTS

Among 397 participants [median age 30 (interquartile range (IQR) 25-34; n  = 198 without HIV, n  = 199 PWH], the prevalence of GDM was 6% (9 PWH versus 3% without HIV). In multivariable analyses, PWH were at higher risk of GDM [risk ratio (RR) 3.9, 95% confidence interval (CI) 1.4-10.7] after adjustment for prepregnancy BMI and other confounders. GDM risk did not differ by ART regimen (unadjusted prevalence 8.1% DTG versus 5.6% EFV, adjusted RR 1.1, 95% CI 0.2-6.6). Few participants had diabetes, impaired glucose tolerance (IGT), or impaired fasting glucose postpartum ( n  = 13, 6%) with no differences by HIV or ART status.

CONCLUSION

In a setting of universal GDM testing, PWH had an increased risk of impaired glucose metabolism during pregnancy but not postpartum. Among PWH, GDM risk was similar regardless of EFV or DTG use. Given concerns about DTG and weight gain, diabetes risk should continue to be monitored.

Skeletal muscle mitochondrial dysfunction in contemporary antiretroviral therapy: a single cell analysis

OBJECTIVE

To quantify mitochondrial function in skeletal muscle of people treated with contemporary antiretroviral therapy.

DESIGN

Cross-sectional observational study.

METHODS

Quantitative multiplex immunofluorescence was performed to determine mitochondrial mass and respiratory chain complex abundance in individual myofibres from tibialis anterior biopsies. Individual myofibres were captured by laser microdissection and mitochondrial DNA (mtDNA) content and large-scale deletions were measured by real-time PCR.

RESULTS

Forty-five antiretroviral therapy (ART)-treated people with HIV (PWH, mean age 58 years, mean duration of ART 125 months) were compared with 15 HIV negative age-matched controls. Mitochondrial complex I (CI) deficiency was observed at higher proportional levels in PWH than negative controls ( P = 0.008). Myofibre mitochondrial mass did not differ by HIV status. No ART class was significantly associated with mitochondrial deficiency, including prior exposure to historical NRTIs (nucleoside analogue reverse transcriptase inhibitors) associated with systemic mitochondrial toxicity. To exclude an effect of untreated HIV, we also studied skeletal muscle from 13 ART-naive PWH (mean age 37). These showed negligible CI defects, as well as comparable myofibre mitochondrial mass to ART-treated PWH. Most CI-deficient myofibres contained mtDNA deletions. No mtDNA depletion was detected.

CONCLUSION

Here, we show that PWH treated with contemporary ART have mitochondrial dysfunction in skeletal muscle, exceeding that expected due to age alone. Surprisingly, this was not mediated by prior exposure to mitochondrially toxic NRTIs, suggesting novel mechanisms of mitochondrial dysfunction in contemporary ART-treated PWH. These findings are relevant for better understanding successful ageing in PWH.

Causes and outcomes of hepatic fibrosis in persons living with HIV

PURPOSE OF REVIEW

The epidemiology of liver disease in people living with HIV has evolved since the arrival of effective hepatitis C virus (HCV) treatment. Nonalcoholic fatty liver disease (NAFLD) in HIV patients is highly prevalent while hepatitis D, hepatitis E, and occult hepatitis B remain underappreciated. We discuss mechanisms of fibrosis in HIV and review clinical outcomes of HIV-associated liver diseases.

RECENT FINDINGS

HIV-HCV co-infection is receding as a cause of progressive liver disease, but fibrosis biomarkers after HCV treatment remain elevated. Antiretroviral therapy (ART) with anti-hepatitis B virus (HBV) activity promotes stable liver disease, but oversimplifying ART regimens in unrecognized suppressed HBV may lead to activation of HBV. A high prevalence of fibrosis and rapid progression of fibrosis are seen in HIV-associated NAFLD, with visceral fat as a major risk factor. Newer ART such as integrase strand inhibitors may have limited intrinsic hepatoxicity but do increase weight, which may secondarily lead to hepatic steatosis. Promising therapies for HIV-associated NAFLD include tesamorelin and CCR5 blockade agents.

SUMMARY

Our understanding of the natural history and pathogenesis of liver diseases in HIV has advanced and adapted to the changing landscape of liver disease in this population. Future research should evaluate long-term clinical and histological outcomes, prevention strategies, and treatment options to improve morbidity and mortality in HIV-related liver diseases.

Exposure of human immune cells, to the antiretrovirals efavirenz and lopinavir, leads to lower glucose uptake and altered bioenergetic cell profiles through interactions with SLC2A1

SLC2A1 mediates glucose cellular uptake; key to appropriate immune function. Our previous work has shown efavirenz and lopinavir exposure inhibits T cell and macrophage responses, to known agonists, likely via interactions with glucose transporters. Using human cell lines as a model, we assessed glucose uptake and subsequent bioenergetic profiles, linked to immunological responses. Glucose uptake was measured using 2-deoxyglucose as a surrogate for endogenous glucose, using commercially available reagents. mRNA expression of SLC transporters was investigated using qPCR TaqMan™ gene expression assay. Bioenergetic assessment, on THP-1 cells, utilised the Agilent Seahorse XF Mito Stress test. In silico analysis of potential interactions between SLC2A1 and antiretrovirals was investigated using bioinformatic techniques. Efavirenz and lopinavir exposure was associated with significantly lower glucose accumulation, most notably in THP-1 cells (up to 90% lower and 70% lower with efavirenz and lopinavir, respectively). Bioenergetic assessment showed differences in the rate of ATP production (J_ATP); efavirenz (4 μg/mL), was shown to reduce J_ATP by 87% whereas lopinavir (10 μg/mL), was shown to increase the overall J_ATP by 77%. Putative in silico analysis indicated the antiretrovirals, apart from efavirenz, associated with the binding site of highest binding affinity to SLC2A1, similar to that of glucose. Our data suggest a role for efavirenz and lopinavir in the alteration of glucose accumulation with subsequent alteration of bioenergetic profiles, supporting our hypothesis for their inhibitory effect on immune cell activation. Clarification of the implications of this data, for in vivo immunological responses, is now warranted to define possible consequences for these, and similar, therapeutics.

Anti-HIV Drugs Cause Mitochondrial Dysfunction in Monocyte-Derived Macrophages

Combination antiretroviral therapy (cART) dramatically changed the face of the HIV/AIDS pandemic, making it one of the most prominent medical breakthroughs of the past 3 decades. However, as the life span of persons living with HIV (PLWH) continues to approach that of the general population, the same cannot be said regarding their quality of life. PLWH are affected by comorbid conditions such as high blood pressure, diabetes, and neurocognitive impairment at a higher rate and increased severity than their age-matched counterparts. PLWH also have higher levels of inflammation, the drivers of which are not entirely clear. As cART treatment is lifelong, we assessed here the effects of cART, independent of HIV, on primary human monocyte-derived macrophages (MDMs). MDMs were unskewed or skewed to an alternative phenotype and treated with Atripla or Triumeq, two first-line cART treatments. We report that Triumeq skewed alternative MDMs toward an inflammatory nonsenescent phenotype. Both Atripla and Triumeq caused mitochondrial dysfunction, specifically efavirenz and abacavir. Additionally, transcriptome sequencing (RNA-seq) demonstrated that both Atripla and Triumeq caused differential regulation of genes involved in immune regulation and cell cycle and DNA repair. Collectively, our data demonstrate that cART, independent of HIV, alters the MDM phenotype. This suggests that cART may contribute to cell dysregulation in PLWH that subsequently results in increased susceptibility to comorbidities.

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.

Microbiota-Meditated Immunity Abnormalities Facilitate Hepatitis B Virus Co-Infection in People Living With HIV: A Review

Hepatitis B virus (HBV) co-infection is fairly common in people living with HIV (PLWH) and affects millions of people worldwide. Identical transmission routes and HIV-induced immune suppression have been assumed to be the main factors contributing to this phenomenon. Moreover, convergent evidence has shown that people co-infected with HIV and HBV are more likely to have long-term serious medical problems, suffer more from liver-related diseases, and have higher mortality rates, compared to individuals infected exclusively by either HIV or HBV. However, the precise mechanisms underlying the comorbid infection of HIV and HBV have not been fully elucidated. In recent times, the human gastrointestinal microbiome is progressively being recognized as playing a pivotal role in modulating immune function, and is likely to also contribute significantly to critical processes involving systemic inflammation. Both antiretroviral therapy (ART)-naïve HIV-infected subjects and ART-treated individuals are now known to be characterized by having gut microbiomic dysbiosis, which is associated with a damaged intestinal barrier, impaired mucosal immunological functioning, increased microbial translocation, and long-term immune activation. Altered microbiota-related products in PLWH, such as lipopolysaccharide (LPS) and short-chain fatty acids (SCFA), have been associated with the development of leaky gut syndrome, favoring microbial translocation, which in turn has been associated with a chronically activated underlying host immune response and hence the facilitated pathogenesis of HBV infection. Herein, we critically review the interplay among gut microbiota, immunity, and HIV and HBV infection, thus laying down the groundwork with respect to the future development of effective strategies to efficiently restore normally diversified gut microbiota in PLWH with a dysregulated gut microbiome, and thus potentially reduce the prevalence of HBV infection in this population.

Integrative Lipidomics and Metabolomics for System-Level Understanding of the Metabolic Syndrome in Long-Term Treated HIV-Infected Individuals

People living with HIV (PLWH) require life-long anti-retroviral treatment and often present with comorbidities such as metabolic syndrome (MetS). Systematic lipidomic characterization and its association with the metabolism are currently missing. We included 100 PLWH with MetS and 100 without MetS from the Copenhagen Comorbidity in HIV Infection (COCOMO) cohort to examine whether and how lipidome profiles are associated with MetS in PLWH. We combined several standard biostatistical, machine learning, and network analysis techniques to investigate the lipidome systematically and comprehensively and its association with clinical parameters. Additionally, we generated weighted lipid-metabolite networks to understand the relationship between lipidomic profiles with those metabolites associated with MetS in PLWH. The lipidomic dataset consisted of 917 lipid species including 602 glycerolipids, 228 glycerophospholipids, 61 sphingolipids, and 26 steroids. With a consensus approach using four different statistical and machine learning methods, we observed 13 differentially abundant lipids between PLWH without MetS and PLWH with MetS, which mainly belongs to diacylglyceride (DAG, n = 2) and triacylglyceride (TAG, n = 11). The comprehensive network integration of the lipidomics and metabolomics data suggested interactions between specific glycerolipids' structural composition patterns and key metabolites involved in glutamate metabolism. Further integration of the clinical data with metabolomics and lipidomics resulted in the association of visceral adipose tissue (VAT) and exposure to earlier generations of antiretroviral therapy (ART). Our integrative omics data indicated disruption of glutamate and fatty acid metabolism, suggesting their involvement in the pathogenesis of PLWH with MetS. Alterations in the lipid homeostasis and glutaminolysis need clinical interventions to prevent accelerated aging in PLWH with MetS.

Macrophages Modulate Hepatic Injury Involving NLRP3 Inflammasome: The Example of Efavirenz

Drug-induced liver injury (DILI) constitutes a clinical challenge due to the incomplete characterization of the mechanisms involved and potential risk factors. Efavirenz, an anti-HIV drug, induces deleterious actions in hepatocytes that could underlie induction of the NLRP3 inflammasome, an important regulator of inflammatory responses during liver injury. We assessed the potential of efavirenz to modulate the inflammatory and fibrogenic responses of major liver cell types involved in DILI. The effects of efavirenz were evaluated both in vitro and in vivo. Efavirenz triggered inflammation in hepatocytes, in a process that involved NF-κB and the NLRP3 inflammasome, and activated hepatic stellate cells (HSCs), thereby enhancing expression of inflammatory and fibrogenic markers. The NLRP3 inflammasome was not altered in efavirenz-treated macrophages, but these cells polarized towards the anti-inflammatory M2 phenotype and displayed upregulated anti-inflammatory mediators. Conversely, no evidence of damage was observed in efavirenz-treated animals, except when macrophages were depleted, which resulted in the in vivo manifestation of the deleterious effects detected in hepatocytes and HSCs. Efavirenz elicits a cell-specific activation of the NLRP3 inflammasome in hepatocytes and HSCs, but macrophages appear to counteract efavirenz-induced liver injury. Our results highlight the dynamic nature of the interaction among liver cell populations and emphasize the potential of targeting macrophage polarization as a strategy to treat NLRP3 inflammasome-induced liver injury.

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.

A Critical Review of the Biochemical Mechanisms and Epigenetic Modifications in HIV- and Antiretroviral-Induced Metabolic Syndrome

Metabolic syndrome (MetS) is a non-communicable disease characterised by a cluster of metabolic irregularities. Alarmingly, the prevalence of MetS in people living with Human Immunodeficiency Virus (HIV) and antiretroviral (ARV) usage is increasing rapidly. This study aimed to look at biochemical mechanisms and epigenetic modifications associated with HIV, ARVs, and MetS. More specifically, emphasis was placed on mitochondrial dysfunction, insulin resistance, inflammation, lipodystrophy, and dyslipidaemia. We found that mitochondrial dysfunction was the most common mechanism that induced metabolic complications. Our findings suggest that protease inhibitors (PIs) are more commonly implicated in MetS-related effects than other classes of ARVs. Furthermore, we highlight epigenetic studies linking HIV and ARV usage to MetS and stress the need for more studies, as the current literature remains limited despite the advancement in and popularity of epigenetics.

Jekyll and Hyde: nuclear receptors ignite and extinguish hepatic oxidative milieu

Nuclear receptors (NRs) are ligand-binding transcription factors that regulate gene networks and physiological responses. Often oxidative stress precedes the onset of liver diseases, and Nrf2 is a key regulator of antioxidant pathways. NRs crosstalk with Nrf2, since NR activation can influence the oxidative milieu by modulating reductive cellular processes. Diet and xenobiotics also regulate NR expression and activity, suggesting a feedback loop. Depending on the tissue context and cues, NRs either increase or decrease toxicity and oxidative damage. Many FDA-approved drugs target NRs, and one could potentially repurpose them to ameliorate reactive oxygen species (ROS). Here, we discuss how several NRs modulate oxidative stress subsequent to diet, organic pollutants, and drug-induced injury to the liver.

Gestational diabetes in women living with HIV in Botswana: lower rates with dolutegravir- than with efavirenz-based antiretroviral therapy

BACKGROUND

There are few data on the prevalence of gestational diabetes (GDM) in pregnant women living with HIV (WLHIV) in sub-Saharan Africa, particularly those using integrase strand transfer inhibitors such as dolutegravir (DTG).

METHODS

We prospectively enrolled pregnant WLHIV and pregnant women without HIV ≥18 years old in Gaborone, Botswana, excluding those with pre-existing diabetes. We screened for GDM using a 75 g oral glucose tolerance test (OGTT) performed at 24-28 weeks' gestation or at the earliest prenatal visit for those presenting after 28 weeks. Logistic regression models were fitted to assess the association between maternal HIV infection and GDM. Subgroup analyses were performed among WLHIV to assess the association between maternal antiretroviral therapy (ART) in pregnancy [DTG vs. efavirenz (EFV) with tenofovir/emtricitabine] and GDM.

RESULTS

Of 486 pregnant women, 66.5% were WLHIV, and they were older than women without HIV (median age 30 vs. 25 years, P < 0.01). Among WLHIV, 97.8% had an HIV-1 RNA level < 400 copies/mL at enrolment. Overall, 8.4% had GDM with similar rates between WLHIV and those without HIV (9.0% vs. 7.4%). The WLHIV receiving DTG-based ART had a 60% lower risk for GDM compared with those on EFV-based ART (adjusted odds ratio = 0.40, 95% CI: 0.18-0.92) after adjusting for confounders.

CONCLUSIONS

Pregnant WLHIV on ART in Botswana were not at increased risk of GDM compared with women without HIV. Among WLHIV, the risk of GDM was lower with DTG- than with EFV-based ART. Further studies with larger cohorts are warranted to confirm these findings.

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.

Analytical and Omics-Based Advances in the Study of Drug-Induced Liver Injury

Drug-induced liver injury (DILI) is a significant clinical issue, affecting 1-1.5 million patients annually, and remains a major challenge during drug development-toxicity and safety concerns are the second-highest reason for drug candidate failure. The future prevalence of DILI can be minimized by developing a greater understanding of the biological mechanisms behind DILI. Both qualitative and quantitative analytical techniques are vital to characterizing and investigating DILI. In vitro assays are capable of characterizing specific aspects of a drug's hepatotoxic nature and multiplexed assays are capable of characterizing and scoring a drug's association with DILI. However, an even deeper insight into the perturbations to biological pathways involved in the mechanisms of DILI can be gained through the use of omics-based analytical techniques: genomics, transcriptomics, proteomics, and metabolomics. These omics analytical techniques can offer qualitative and quantitative insight into genetic susceptibilities to DILI, the impact of drug treatment on gene expression, and the effect on protein and metabolite abundance. This review will discuss the analytical techniques that can be applied to characterize and investigate the biological mechanisms of DILI and potential predictive biomarkers.

NNRTI and Liver Damage: Evidence of Their Association and the Mechanisms Involved

Due to the improved effectiveness and safety of combined antiretroviral therapy, human immunodeficiency virus (HIV) infection has become a manageable, chronic condition rather than a mortal disease. However, HIV patients are at increased risk of experiencing non-AIDS-defining illnesses, with liver-related injury standing out as one of the leading causes of death among these patients. In addition to more HIV-specific processes, such as antiretroviral drug-related toxicity and direct injury to the liver by the virus itself, its pathogenesis is related to conditions that are also common in the general population, such as alcoholic and non-alcoholic fatty liver disease, viral hepatitis, and ageing. Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are essential components of combined anti-HIV treatment due to their unique antiviral activity, high specificity, and acceptable toxicity. While first-generation NNRTIs (nevirapine and efavirenz) have been related largely to liver toxicity, those belonging to the second generation (etravirine, rilpivirine and doravirine) seem to be generally safe for the liver. Indeed, there is preclinical evidence of rilpivirine being hepatoprotective in different models of liver injury, independently of the presence of HIV. The present study aims to review the mechanisms by which currently available anti-HIV drugs belonging to the NNRTI family may participate in the development of liver disease.

Physiologically Relevant Concentrations of Dolutegravir, Emtricitabine, and Efavirenz Induce Distinct Metabolic Alterations in HeLa Epithelial and BV2 Microglial Cells

Microglia, the resident brain phagocytes, likely play a key role in human immunodeficiency virus (HIV) infection of the central nervous system (CNS) and subsequent neuropathogenesis; however, the nature of the infection-induced changes that yield damaging CNS effects and the stimuli that provoke microglial activation remains elusive, especially in the current era of using antiretroviral (ARV) drugs for ARV therapy (ART). Altered microglial metabolism can modulate cellular functionality and pathogenicity in neurological disease. While HIV infection itself alters brain energy metabolism, the effect of ARV drugs, particularly those currently used in treatment, on metabolism is understudied. Dolutegravir (DTG) and emtricitabine (FTC) combination, together with tenofovir (TAF or TDF), is one of the recommended first line treatments for HIV. Despite the relatively good tolerability and safety profile of FTC, a nucleoside reverse transcriptase inhibitor, and DTG, an integrase inhibitor, adverse side effects have been reported and highlight a need to understand off-target effects of these medications. We hypothesized that similar to previous ART regimen drugs, DTG and FTC side effects involve mitochondrial dysfunction. To increase detection of ARV-induced mitochondrial effects, highly glycolytic HeLa epithelial cells were forced to rely on oxidative phosphorylation by substituting galactose for glucose in the growth media. We assessed ATP levels, resazurin oxidation-reduction (REDOX), and mitochondrial membrane potential following 24-hour exposure (to approximate effects of one dose equivalent) to DTG, FTC, and efavirenz (EFV, a known mitotoxic ARV drug). Further, since microglia support productive HIV infection, act as latent HIV cellular reservoirs, and when dysfunctional likely contribute to HIV-associated neurocognitive disorders, the experiments were repeated using BV2 microglial cells. In HeLa cells, FTC decreased mitochondrial REDOX activity, while DTG, similar to EFV, impaired both mitochondrial ATP generation and REDOX activity. In contrast to HeLa cells, DTG increased cellular ATP generation and mitochondrial REDOX activity in BV2 cells. Bioenergetic analysis revealed that DTG, FTC, and EFV elevated BV2 cell mitochondrial respiration. DTG and FTC exposure induced distinct mitochondrial functional changes in HeLa and BV2 cells. These findings suggest cell type-specific metabolic changes may contribute to the toxic side effects of these ARV drugs.

Psoriasis and Liver Damage in HIV-Infected Patients

Background/objectives: Psoriasis is the most frequent skin disease in HIV-infected patients. Nonalcohol fatty liver disease (NAFLD) is more prevalent in patients with psoriasis. We report the prevalence of psoriasis and NAFLD and investigate risk factors of liver damage in HIV-infected patients with psoriasis. Methods: We performed a retrospective observational study. Steatosis was defined as indicative abdominal ultrasound findings, CAP (controlled attenuated parameter by transient elastography) > 238 dB/m, and/or triglyceride and glucose index (TyG) > 8.38. Significant (fibrosis ≥ 2) and advanced liver fibrosis (fibrosis ≤ F3) were studied by transient elastography (TE) and/or FIB-4 using standard cutoff points. FIB-4 (Fibrosis 4 score) results were adjusted for hepatitis C (HCV)-coinfected patients. Results: We identified 80 patients with psoriasis (prevalence, 1.5%; 95% CI, 1.1–1.8). Psoriasis was severe (PASI > 10 and/or psoriatic arthritis) in 27.5% of cases. The prevalence of steatosis was 72.5% (95% CI, 65–85). Severe psoriasis was an independent risk factor for steatosis (OR, 12; 95% CI, 1.2–120; p = 0.03). Significant liver fibrosis (p < 0.05) was associated with HCV coinfection (OR 3.4; 95% CI, 1.1–10.6), total CD4 (OR 0.99; 95% CI, 0.99–1), and time of efavirenz exposure (OR 1.2; 95% CI, 1.0–1.3). Conclusions: The prevalence of psoriasis in HIV-infected patients was similar to that of the general population. Steatosis is highly prevalent, and severe psoriasis is an independent risk factor for steatosis in HIV-infected patients.

Cerebral Vascular Toxicity of Antiretroviral Therapy

HIV infection is associated with comorbidities that are likely to be driven not only by HIV itself, but also by the toxicity of long-term use of antiretroviral therapy (ART). Indeed, increasing evidence demonstrates that the antiretroviral drugs used for HIV treatment have toxic effects resulting in various cellular and tissue pathologies. The blood-brain barrier (BBB) is a modulated anatomophysiological interface which separates and controls substance exchange between the blood and the brain parenchyma; therefore, it is particularly exposed to ART-induced toxicity. Balancing the health risks and gains of ART has to be considered in order to maximize the positive effects of therapy. The current review discusses the cerebrovascular toxicity of ART, with the focus on mitochondrial dysfunction. Graphical Abstract Graphical representation of the interactions between HIV, antiretroviral therapy (ART), and the blood-brain barrier (BBB).

Apoptosis of Hepatocytes: Relevance for HIV-Infected Patients under Treatment

Due to medical advances over the past few decades, human immunodeficiency virus (HIV) infection, once a devastatingly mortal pandemic, has become a manageable chronic condition. However, available antiretroviral treatments (cART) cannot fully restore immune health and, consequently, a number of inflammation-associated and/or immunodeficiency complications have manifested themselves in treated HIV-infected patients. Among these chronic, non-AIDS (acquired immune deficiency syndrome)-related conditions, liver disease is one of the deadliest, proving to be fatal for 15–17% of these individuals. Aside from the presence of liver-related comorbidities, including metabolic disturbances and co-infections, HIV itself and the adverse effects of cART are the main factors that contribute to hepatic cell injury, inflammation, and fibrosis. Among the molecular mechanisms that are activated in the liver during HIV infection, apoptotic cell death of hepatocytes stands out as a key pathogenic player. In this review, we will discuss the evidence and potential mechanisms involved in the apoptosis of hepatocytes induced by HIV, HIV-encoded proteins, or cART. Some antiretroviral drugs, especially the older generation, can induce apoptosis of hepatic cells, which occurs through a variety of mechanisms, such as mitochondrial dysfunction, increased production of reactive oxygen species (ROS), and induction of endoplasmic reticulum (ER) stress and unfolded protein response (UPR), all of which ultimately lead to caspase activation and cell death.

Switch to Efavirenz Attenuates Lipoatrophy in Girls With Perinatal HIV

OBJECTIVES

Children with HIV (CHIV) have lifetime exposure to antiretrovirals (ART); therefore, optimizing their regimens to have the least impact on fat redistribution is a priority.

METHODS

This is a cross-sectional study of 219 perinatally infected CHIV and 219 HIV-uninfected controls from similar socioeconomic backgrounds in Johannesburg, South Africa. We compared total body and regional fat distribution in CHIV on suppressive ART regimens with controls and, among CHIV, between ritonavir-boosted lopinavir (LPV/r)-based and efavirenz (EFV)-based regimens.

RESULTS

The mean age of the 219 uninfected children (45% girls) and the 219 CHIV (48% girls) was 7.0 and 6.4 years, respectively. CHIV had lower adjusted total body fat (P = 0.005) and lower percentage fat at the trunk (P = 0.020), arms (P = 0.001), and legs (P < 0.001) than uninfected children. CHIV on LPV/r had similar body composition as those on EFV, except for arm fat mass (P = 0.030). When stratified by sex, girls with HIV on LPV/r had lower adjusted total (P = 0.007), trunk (P = 0.002), arms (P = 0.008), legs (P = 0.048) fat mass; trunk-to-total body fat (P = 0.044); and higher legs-to-total body fat (P = 0.011) than those on EFV.

CONCLUSIONS

South African CHIV receiving ART had lower global and partial fat mass and percentage fat than healthy controls. In girls with HIV with sustained virologic suppression on ART, switching from LPV/r to EFV could attenuate fat mass loss, indicating that EFV-based regimen may be a better option in this group of individuals.

Insights Into the Pathophysiology of Liver Disease in HCV/HIV: Does it End With HCV Cure?

HCV-HIV coinfected patients exhibit rapid progression of liver damage relative to HCV monoinfected patients. The availability of new directly acting antiviral agents has dramatically improved outcomes for coinfected patients as sustained virologic response rates now exceed 95% and fibrosis-related parameters are improved. Nevertheless, coinfected patients still have a higher mortality risk and more severe hepatocellular carcinoma compared to HCV monoinfected patients, implying the existence of pathways unique to people living with HIV that continue to promote accelerated liver disease. In this article, we review the pathobiology of liver disease in HCV-HIV coinfected patients in the directly acting antiviral era and explore the mechanisms through which HIV itself induces liver damage. Since liver disease is one of the leading causes of non-AIDS-related mortality in HIV-positive patients, enhancing our understanding of HIV-associated fibrotic pathways will remain important for new diagnostic and therapeutic strategies to slow or reverse liver disease progression, even after HCV cure.

N-Acetylcysteine Reverses Antiretroviral-Mediated Microglial Activation by Attenuating Autophagy-Lysosomal Dysfunction

Successful suppression of viral replication by combined antiretroviral therapy (cART) in HIV-1 infected individuals is paradoxically also accompanied by an increased prevalence of HIV-associated neurocognitive disorders (HAND) in these individuals. HAND is characterized by a state of chronic oxidative stress and inflammation. Microglia are extremely sensitive to a plethora of stimuli, including viral proteins and cART. The current study aimed to assess the effects of cART-mediated oxidative stress on the induction of inflammatory responses in microglia. In the present study, we chose a combination of three commonly used antiretroviral drugs—tenofovir disoproxil fumarate, emtricitabine, and dolutegravir. We demonstrated that exposure of microglia to the chosen cART cocktail induced generation of reactive oxygen species, subsequently leading to lysosomal dysfunction and dysregulated autophagy, ultimately resulting in the activation of microglia. Intriguingly, the potent antioxidant, N-acetylcysteine, reversed the damaging effects of cART. These in vitro findings were further corroborated in vivo wherein cART-treated HIV transgenic (Tg) rats demonstrated increased microglial activation, exaggerated lysosome impairment, and dysregulated autophagy in the prefrontal cortices compared with HIV Tg rats not exposed to cART. Similar to in vitro findings, the treatment of HIV Tg rats with N-acetylcysteine also mitigated the deleterious effects of cART. Taken together, our findings suggest that oxidative stress-mediated lysosomal dysfunction plays a critical role in the pathogenesis of HAND in drug-treated HIV-infected individuals and that antioxidant-mediated mitigation of oxidative stress could thus be considered as an adjunctive therapeutic strategy for ameliorating/dampening some of the neurological complications of HAND.

Redox-dependent PPARγ/Tnpo1 complex formation enhances PPARγ nuclear localization and signaling

The nuclear receptor peroxisome proliferator-activated receptor (PPAR)γ has been implicated in the pathogenesis of various human diseases including fatty liver. Although nuclear translocation of PPARγ plays an important role in PPARγ signaling, details of the translocation mechanisms have not been elucidated. Here we demonstrate that PPARγ2 translocates to the nucleus and activates signal transduction through H₂O₂-dependent formation of a PPARγ2 and transportin (Tnpo)1 complex via redox-sensitive disulfide bonds between cysteine (Cys)176 and Cys180 of the former and Cys512 of the latter. Using hepatocyte cultures and mouse models, we show that cytosolic H₂O₂/Tnpo1-dependent nuclear translocation enhances the amount of DNA-bound PPARγ and downstream signaling, leading to triglyceride accumulation in hepatocytes and liver. These findings expand our understanding of the mechanism underlying the nuclear translocation of PPARγ, and suggest that the PPARγ and Tnpo1 complex and surrounding redox environment are potential therapeutic targets in the treatment of PPARγ-related diseases.

Mechanistic insights into antiretroviral drug-induced liver injury

All classes of antiretroviral therapy (ART) have been implicated to induce adverse drug reactions such drug-induced liver injury (DILI) and immune-mediated adverse reactions in Human Immunodeficiency Virus (HIV) infected individuals. Patients that develop adverse drug reactions tend to have prolonged stays in hospital and may require to change to alternative regimens if reactions persist upon rechallenge or if rechallenge is contraindicated due to severity of the adverse reaction. Diagnosis of DILI remains a huge obstacle that delays timely interventions, since it is still based largely on exclusion of other causes. There is an urgent need to develop robust diagnostic and predictive biomarkers that could be used alongside the available tools (biopsy, imaging, and serological tests for liver enzymes) to give a specific diagnosis of DILI. Crucial to this is also achieving consensus in the definition of DILI so that robust studies can be undertaken. Importantly, it is crucial that we gain deeper insights into the mechanism of DILI so that patients can receive appropriate management. In general, it has been demonstrated that the mechanism of ART-induced liver injury is driven by four main mechanisms: mitochondrial toxicity, metabolic host-mediated injury, immune reconstitution, and hypersensitivity reactions. The focus of this review is to discuss the type and phenotypes of DILI that are caused by the first line ART regimens. Furthermore, we will summarize recent studies that have elucidated the cellular and molecular mechanisms of DILI both in vivo and in vitro.

Implications of lipid droplets in lung cancer: Associations with drug resistance

Cancer cells usually show different metabolic patterns compared with healthy cells due to the reprogramming of metabolic processes. The process of lipid metabolism undergoes notable changes, leading to the accumulation of lipid droplets in cells. Additionally, this phenotype is considered an important marker of cancer cells. Lipid droplets are a highly dynamic type of organelle in the cell, which is composed of a neutral lipid core, a monolayer phospholipid membrane and lipid droplet-related proteins. Lipid droplets are involved in several biological processes, including cell proliferation, apoptosis, lipid metabolism, stress, immunity, signal transduction and protein trafficking. Epidermal growth factor receptor (EGFR)-activating mutations are currently the most effective therapeutic targets for non-small cell lung cancer. Several EGFR tyrosine kinase inhibitors (EGFR-TKIs) that target these mutations, including gefitinib, erlotinib, afatinib and osimertinib, have been widely used clinically. However, the development of acquired resistance has a major impact on the efficacy of these drugs. A number of previous studies have reported that the expression of lipid droplets in the tumor tissues of patients with lung cancer are elevated, whereas the association between elevated numbers of lipid droplets and drug resistance has received little attention. The present review describes the potential association between lipid droplets and drug resistance. Furthermore, the mechanisms and implications of lipid droplet accumulation in cancer cells are analyzed, as wells as the mechanism by which lipid droplets suppress endoplasmic reticulum stress and apoptosis, which are essential for the development and treatment of lung cancer.

Rilpivirine attenuates liver fibrosis through selective STAT1-mediated apoptosis in hepatic stellate cells

OBJECTIVE

Liver fibrosis constitutes a major health problem worldwide due to its rapidly increasing prevalence and the lack of specific and effective treatments. Growing evidence suggests that signalling through cytokine-activated Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathways regulates liver fibrosis and regeneration. Rilpivirine (RPV) is a widely used anti-HIV drug not reported to produce hepatotoxicity. We aimed to describe the potential hepatoprotective effects of RPV in different models of chronic liver injury, focusing on JAK-STAT signalling regulation.

DESIGN

The effects of RPV on hepatic steatosis, inflammation and fibrogenesis were studied in a nutritional mouse model of non-alcoholic fatty liver disease, carbon tetrachloride-induced fibrosis and bile duct ligation-induced fibrosis. Primary human hepatic stellate cells (hHSC) and human cell lines LX-2 and Hep3B were used to investigate the underlying molecular mechanisms.

RESULTS

RPV exerted a clear anti-inflammatory and antifibrotic effect in all the in vivo models of liver injury employed, and enhanced STAT3-dependent proliferation in hepatocytes and apoptosis in HSC through selective STAT1 activation. These results were reproduced in vitro; RPV undermined STAT3 activation and triggered STAT1-mediated pathways and apoptosis in HSC. Interestingly, this selective pro-apoptotic effect completely disappeared when STAT1 was silenced. Conditioned medium experiments showed that HSC apoptosis activated STAT3 in hepatocytes in an interleukin-6-dependent mechanism.

CONCLUSION

RPV ameliorates liver fibrosis through selective STAT1-dependent induction of apoptosis in HSC, which exert paracrinal effects in hepatocytes, thus promoting liver regeneration. RPV's actions may represent an effective strategy to treat chronic liver diseases of different aetiologies and help identify novel therapeutic targets.

Genomic Instability Decreases in HIV Patient by Complementary Therapy with Rosmarinus officinalis Extracts

Genomic instability is associated with increased oxidative stress in patients with human immunodeficiency virus (HIV). The aim of this study was to determine the effect of intake of methanolic and aqueous extracts of Rosmarinus officinalis on genomic instability in HIV patients. We studied 67 HIV patients under pharmacological treatment with ATRIPLA who were divided into three groups: group 1, patients under ATRIPLA antiretroviral therapy; group 2, patients with ATRIPLA and rosemary aqueous extract (4 g/L per day); and group 3, patients with ATRIPLA and rosemary methanolic extract (400 mg/day). The genomic instability was evaluated through the buccal micronucleus cytome assay. Oral epithelial cells were taken at the beginning and 1 and 4 months later. The groups that received the pharmacological therapy with ATRIPLA and the complementary therapy with R. officinalis extracts showed a decrease in the number of cells with micronuclei and nuclear abnormalities compared with the group that only received ATRIPLA. The complementary therapy with R. officinalis decreased the genomic instability 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.

A comparison of machine learning techniques for classification of HIV patients with antiretroviral therapy-induced mitochondrial toxicity from those without mitochondrial toxicity

BACKGROUND

Antiretroviral therapy (ART) has significantly reduced HIV-related morbidity and mortality. However, therapeutic benefit of ART is often limited by delayed drug-associated toxicity. Nucleoside reverse transcriptase inhibitors (NRTIs) are the backbone of ART regimens. NRTIs compete with endogenous deoxyribonucleotide triphosphates (dNTPs) in incorporation into elongating DNA chain resulting in their cytotoxic or antiviral effect. Thus, the efficacy of NRTIs could be affected by direct competition with endogenous dNTPs and/or feedback inhibition of their metabolic enzymes. In this paper, we assessed whether the levels of ribonucleotides (RN) and dNTP pool sizes can be used as biomarkers in distinguishing between HIV-infected patients with ART-induced mitochondrial toxicity and HIV-infected patients without toxicity.

METHODS

We used data collected through a case-control study from 50 subjects. Cases were defined as HIV-infected individuals with clinical and/or laboratory evidence of mitochondrial toxicity. Each case was age, gender, and race matched with an HIV-positive without evidence of toxicity. We used a range of machine learning procedures to distinguish between patients with and without toxicity. Using resampling methods like Monte Carlo k-fold cross validation, we compared the accuracy of several machine learning algorithms applied to our data. We used the algorithm with highest classification accuracy rate in evaluating the diagnostic performance of 12 RN and 14 dNTP pool sizes as biomarkers of mitochondrial toxicity.

RESULTS

We used eight classification algorithms to assess the diagnostic performance of RN and dNTP pool sizes distinguishing HIV patients with and without NRTI-associated mitochondrial toxicity. The algorithms resulted in cross-validated classification rates of 0.65-0.76 for dNTP and 0.72-0.83 for RN, following reduction of the dimensionality of the input data. The reduction of input variables improved the classification performance of the algorithms, with the most pronounced improvement for RN. Complex tree-based methods worked the best for both the deoxyribose dataset (Random Forest) and the ribose dataset (Classification Tree and AdaBoost), but it is worth noting that simple methods such as Linear Discriminant Analysis and Logistic Regression were very competitive in terms of classification performance.

CONCLUSIONS

Our finding of changes in RN and dNTP pools in participants with mitochondrial toxicity validates the importance of dNTP pools in mitochondrial function. Hence, levels of RN and dNTP pools can be used as biomarkers of ART-induced mitochondrial toxicity.

Mitochondrial dysfunctions in HIV infection and antiviral drug treatment

Introduction: With the introduction of highly active anti-retroviral therapy (HAART), treatment of HIV infection has improved radically, shifting the concept of HIV disease from a highly mortal epidemic to a chronic illness which needs systematic management. However, HAART does not target the integrated proviral DNA. Hence, prolonged use of antiviral drugs is needed for sustaining life. As a consequence, severe side effects emerge. Several parameters involve in causing these adverse effects. Mitochondrial dysfunctions were pointed as common factor among them. It is, therefore, necessary to critically examine mitochondrial dysfunction in order to understand the side effects.Areas covered: There are many events involved in causing drug-induced side-effects; in this review, we only highlight mitochondrial dysfunctions as one of the events. We present up-to-date findings on mitochondrial dysfunction caused by HIV infection and antiviral drug treatment. Both in vivo and in vitro studies on mitochondrial dysfunction like change in morphology, membrane depolarization, mitophagy, mitochondrial DNA depletion, and intrinsic apoptosis have been discussed.Expert opinion: Mitochondrial dysfunction is associated with severe complications that often lead to discontinuation or change in treatment regimen. Prior knowledge of side effects of antiviral drugs would help in better management and future research should focus to avoid mitochondrial targeting of antiviral drugs while maintaining their antiviral properties.

MicroRNA Mediated Changes in Drug Metabolism and Target Gene Expression by Efavirenz and Rifampicin In Vitro: Clinical Implications

Efavirenz (EFV) and rifampicin (RMP) are widely prescribed in Africa for treatment of HIV/AIDS and tuberculosis epidemics. Exposure to medicines can alter drug metabolism, for example, through changes in expression of microRNAs. We report, in this study, novel observations on the ways in which EFV and RMP change microRNA expression signatures in vitro in HepaRG cells. Additionally, we discuss the clinical implications of changes in expression of drug-metabolizing enzyme genes, such as CYP3A4, CYP3A5, UGT1A1, CYP2B6, and NR1I3. Differentiated HepaRG cells were treated with EFV (6.4 μM) or RMP (24.4 μM) for 24 h. Treatment of HepaRG cells with EFV resulted in a significant increase in messenger RNA (mRNA) expression for CYP3A4 (12.51-fold, p = 0.002), CYP3A5 (2.10-fold, p = 0.019), and UGT1A1 (2.52-fold, p = 0.005), whereas NR1I3 expression decreased (0.41-fold, p = 0.02). On the other hand, treatment of HepaRG cells with RMP resulted in a significant increase in mRNA expression for CYP2B6 (6.68-fold, p = 0.007) and CYP3A4 (111.96-fold, p = 0.001), whereas NR1I3 expression decreased (0.46-fold, p = 0.033). These data point to several important clinical implications through changes in drug/drug interaction risks and achieving optimal therapeutics. All in all, this study shows that differential expression of microRNAs after treatment with EFV and RMP adds another layer of complexity that should be incorporated in pharmacogenomic algorithms to render drug response more predictable.

Improvement in liver steatosis after the switch from a ritonavir-boosted protease inhibitor to raltegravir in HIV-infected patients with non-alcoholic fatty liver disease

Background: The ritonavir-boosted protease inhibitor (PI/r) use has been associated with several metabolic abnormalities, and the non-alcoholic fatty liver disease (NAFLD) is becoming a very frequent comorbidity among HIV-infected patients. Methods: We performed an observational, prospective study of HIV-infected patients with NAFLD, receiving one PI/r plus two nucleoside analogues, who switched from the PI/r to raltegravir or were treated only with lifestyle modification, maintaining antiretroviral therapy unchanged. Changes in liver steatosis after 12 months were evaluated by transient elastography and measurement of controlled attenuation parameter (CAP). Results: As a whole, 61 patients (46 males; median age, 55.4 years) were enrolled, and 32 of them have been switched from PI/r to raltegravir. At baseline, median CAP was 259 dB/m, 28 (45.9%) subjects had a moderate-to-severe hepatic steatosis (CAP ≥260 dB/m), and 19 patients (31.1%) had elevated aminotransferases. Type-2 diabetes mellitus was present in 5 persons, and chronic HCV coinfection in 4. At month 12, the median decrease in CAP values was -27 dB/m in patients switched to raltegravir and -11 dB/m in those with unchanged cART (p = .021). The number of patients with CAP ≥260 dB/m decreased from 16 to 6 (-62.5%) in patients switched to raltegravir and from 12 to 8 (-33.3%) in the other group (p = .037). Conclusion: After 12 months, HIV-infected patients with NAFLD switching from a PI/r to raltegravir showed a significantly greater decrease in the hepatic steatosis degreee in comparison with those with unchanged cART and treated only with lifestyle modification.

Efavirenz is associated with altered fronto-striatal function in HIV+ adolescents

Neurotoxicity associated with the antiretroviral efavirenz (EFV) has been documented in HIV-infected adults, but there are no data on the impact of EFV on brain function in adolescents. We investigated potential alterations in fronto-striatal function associated with EFV use in adolescents. A total of 86 adolescents underwent a Stop Signal Anticipation Task (SSAT) during functional MRI (fMRI), 39 HIV+ adolescents receiving EFV, 27 HIV+ adolescents on antiretroviral therapy without EFV (matched on age, gender, education, CD4 cell count and HIV viral load) and 20 HIV- matched controls (matched on age and gender). The task required participants to give timed GO responses with occasional STOP signals at fixed probabilities. Reactive inhibition was modelled as a correct STOP response and proactive inhibition was modelled after response slowing as the STOP probability increases. A priori mask-based regions associated with reactive and proactive inhibition were entered into two respective multivariate ANOVAs. The EFV treatment group showed significantly blunted proactive inhibitory behavioural responses compared to HIV+ adolescents not receiving EFV. There was no difference in reactive inhibition between treatment groups. We also demonstrated a significant effect of EFV treatment on BOLD signal in proactive inhibition regions. There was no difference in regions involved in reactive inhibition. We found no differences between adolescents not receiving EFV and HIV- controls, showing that functional and behavioural differences were unique to the EFV group. Here, we demonstrate for the first time a potential adverse impact of EFV on higher cortical function in young HIV+ adolescents.

Morphine counteracts the antiviral effect of antiretroviral drugs and causes upregulation of p62/SQSTM1 and histone-modifying enzymes in HIV-infected astrocytes

Accelerated neurological disorders are increasingly prominent among the HIV-infected population and are likely driven by the toxicity from long-term use of antiretroviral drugs. We explored potential side effects of antiretroviral drugs in HIV-infected primary human astrocytes and whether opioid co-exposure exacerbates the response. HIV-infected human astrocytes were exposed to the reverse transcriptase inhibitor, emtricitabine, alone or in combination with two protease inhibitors ritonavir and atazanavir (ERA) with and without morphine co-exposure. The effect of the protease inhibitor, lopinavir, alone or in combination with the protease inhibitor, abacavir, and the integrase inhibitor, raltegravir (LAR), with and without morphine co-exposure was also explored. Exposure with emtricitabine alone or ERA in HIV-infected astrocytes caused a significant decrease in viral replication and attenuated HIV-induced inflammatory molecules, while co-exposure with morphine negated the inhibitory effects of ERA, leading to increased viral replication and inflammatory molecules. Exposure with emtricitabine alone or in combination with morphine caused a significant disruption of mitochondrial membrane integrity. Genetic analysis revealed a significant increase in the expression of p62/SQSTM1 which correlated with an increase in the histone-modifying enzyme, ESCO2, after exposure with ERA alone or in combination with morphine. Furthermore, several histone-modifying enzymes such as CIITA, PRMT8, and HDAC10 were also increased with LAR exposure alone or in combination with morphine. Accumulation of p62/SQSTM1 is indicative of dysfunctional lysosomal fusion. Together with the loss of mitochondrial integrity and epigenetic changes, these effects may lead to enhanced viral titer and inflammatory molecules contributing to the neuropathology associated with HIV.

Reactive Oxygen Species Induces Lipid Droplet Accumulation in HepG2 Cells by Increasing Perilipin 2 Expression

Non-alcoholic fatty liver disease (NAFLD) has become the world's most common liver disease. The disease can develop liver fibrosis or even carcinomas from the initial hepatic steatosis, and this process is influenced by many factors. Reactive oxygen species (ROS), as potent oxidants in cells, have been reported previously to play an important role in the development of NAFLD progression via promoting neutral lipid accumulation. Here, we found that ROS can promote lipid droplet formation in hepatocytes by promoting perilipin2 (PLIN2) expression. First, we used different concentrations of hydrogen peroxide to treat HepG2 cells and found that the number of lipid droplets in the cells increased, however also that this effect was dose-independent. Then, the mRNA level of several lipid droplet-associated genes was detected with hydrogen peroxide treatment and the expression of PLIN2, PLIN5, and FSP27 genes was significantly up-regulated (p < 0.05). We overexpressed PLIN2 in HepG2 cells and found that the lipid droplets in the cells were markedly increased. Interference with PLIN2 inhibits ROS-induced lipid droplet formation, revealing that PLIN2 is a critical factor in this process. We subsequently analyzed the regulatory pathway and protein interaction network that is involved in PLIN2 and found that PLIN2 can regulate intracellular lipid metabolism through the PPARα/RXRA and CREB/CREBBP signaling pathways. The majority of the data indicated the correlation between hydrogen peroxide-induced PLIN2 and lipid droplet upregulation. In conclusion, ROS up-regulates the expression of PLIN2 in hepatocytes, whereas PLIN2 promotes the formation of lipid droplets resulting in lipid accumulation in liver tissues.

Differential contribution of chronic binge alcohol and antiretroviral therapy to metabolic dysregulation in SIV-infected male macaques

The incidence of alcohol use disorder (AUD) is higher among people living with HIV (PLWH). The advent and continued development of antiretroviral therapy (ART) has significantly reduced mortality, shifting the course of HIV infection to a chronic illness. However, this is associated with an increased incidence of comorbid conditions, including type 2 diabetes mellitus, insulin resistance, and cardiovascular complications. Using a nonhuman primate model of simian immunodeficiency virus (SIV) infection, previous studies have demonstrated that chronic binge alcohol (CBA) administration decreases whole body insulin responsiveness, irrespective of ART administration. The objective of the current study was to determine the effects of CBA and ART on insulin-sensitive peripheral tissues before the development of overt clinical symptoms of SIV disease. Our results show that CBA reduced omental adipocyte cell size, increased collagen expression, and decreased the in vitro differentiation potential of adipose-derived stem cells. In contrast, it did not alter skeletal muscle or omental or hepatic expression of insulin signaling proteins. However, ART significantly decreased skeletal muscle expression of phosphatase and tensin homolog, total mechanistic target of rapamycin, and ribosomal protein S6. In addition, ART increased hepatic phosphorylation of AMP-activated protein kinase α and increased gene expression of key enzymes required for gluconeogenesis and fatty acid synthesis. These findings suggest that CBA and ART differentially promote adverse metabolic effects in an organ-specific manner that may underlie insulin resistance associated with alcohol, SIV, and ART. Whether this is translated in PLWH with AUD remains to be determined.

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.

Absence of effect of the antiretrovirals Duovir and Viraday on mitochondrial bioenergetics

Most toxicity associated with antiretroviral drugs is thought to result from disruption of mitochondrial function. Unfortunately, there are no validated laboratory markers for clinically assessing the onset of mitochondrial toxicity associated with antiretroviral therapy. In a previous study on mitochondrial hepatocytes, the protease inhibitor lopimune was shown to induce mitochondrial toxicity by increasing reactive oxygen species (ROS) production and decreasing respiratory control ratio (RCR) reflecting compromised mitochondrial efficiency in adenosine triphosphate production. Mitochondrial dysfunction and ROS production were directly correlated with the expression of uncoupling protein 2 (UCP2). In the current study we aim to determine the toxicity of nucleoside or nucleotide and nonnucleoside reverse-transcriptase inhibitors, Duovir and Viraday on liver mitochondria isolated from treated mice by monitoring UCP2 expression. Our results showed that both Duovir and Viraday had no effect on mitochondrial respiration states 2, 3, 4, and on RCR. In addition, ROS generation and UCP2 expression were not affected. In conclusion, our results indicate the difference in the mechanism of action of distinct classes of antiretroviral drugs on mitochondrial functions and may associate UCP2 expression with subclinical mitochondrial damage as marker of cellular oxidative stress.