Adult Human Brain Tissue Cultures to Study NeuroHIV.

HIV-associated neurocognitive disorders (HAND) persist under antiretroviral therapy as a complex pathology that has been difficult to study in cellular and animal models. Therefore, we generated an ex vivo human brain slice model of HIV-1 infection from surgically resected adult brain tissue. Brain slice cultures processed for flow cytometry showed >90% viability of dissociated cells within the first three weeks in vitro, with parallel detection of astrocyte, myeloid, and neuronal populations. Neurons within brain slices showed stable dendritic spine density and mature spine morphologies in the first weeks in culture, and they generated detectable activity in multi-electrode arrays. We infected cultured brain slices using patient-matched CD4+ T-cells or monocyte-derived macrophages (MDMs) that were exposed to a GFP-expressing R5-tropic HIV-1 in vitro. Infected slice cultures expressed viral RNA and developed a spreading infection up to 9 days post-infection, which were significantly decreased by antiretrovirals. We also detected infected myeloid cells and astrocytes within slices and observed minimal effect on cellular viability over time. Overall, this human-centered model offers a promising resource to study the cellular mechanisms contributing to HAND (including antiretroviral toxicity, substance use, and aging), infection of resident brain cells, and new neuroprotective therapeutics.

Lack of Association of Vascular Risk Factors with HIV-Associated Neurocognitive Disorders in cART-Treated Adults Aged ≥ 50 Years in Tanzania.

HIV-associated neurocognitive disorders (HAND) are highly prevalent in those ageing with HIV. High-income country data suggest that vascular risk factors (VRFs) may be stronger predictors of HAND than HIV-disease severity, but data from sub-Saharan Africa are lacking. We evaluated relationships of VRFs, vascular end-organ damage and HAND in individuals aged ≥ 50 in Tanzania. c-ART-treated individuals were assessed for HAND using consensus criteria. The prevalence of VRFs and end organ damage markers were measured. The independent associations of VRFs, end organ damage and HAND were examined using multivariable logistic regression. Data were available for 153 individuals (median age 56, 67.3% female). HAND was highly prevalent (66.7%, 25.5% symptomatic) despite well-managed HIV (70.5% virally suppressed). Vascular risk factors included hypertension (34%), obesity (10.5%), hypercholesterolemia (33.3%), diabetes (5.3%) and current smoking (4.6%). End organ damage prevalence ranged from 1.3% (prior myocardial infarction) to 12.5% (left ventricular hypertrophy). Measured VRFs and end organ damage were not independently associated with HAND. The only significant association was lower diastolic BP (p 0.030, OR 0.969 (0.943-0.997). Our results suggest that vascular risk factors are not major drivers of HAND in this setting. Further studies should explore alternative aetiologies such as chronic inflammation.

Underlying Neural Mechanisms of Cognitive Improvement in Fronto-striatal Response Inhibition in People Living with HIV Switching Off Efavirenz: A Randomized Controlled BOLD fMRI Trial.

INTRODUCTION: It is unclear whether neurotoxicity due to the antiretroviral drug efavirenz (EFV) results in neurocognitive impairment in people living with HIV (PLWH). Previously, we found that discontinuing EFV was associated with improved processing speed and attention on neuropsychological assessment. In this imaging study, we investigate potential neural mechanisms underlying this cognitive improvement using a BOLD fMRI task assessing cortical and subcortical functioning. METHODS: Asymptomatic adult PLWH stable on emtricitabine/tenofovirdisoproxil/efavirenz were randomly (1:2) assigned to continue their regimen (n = 12) or to switch to emtricitabine/tenofovirdisoproxil/rilpivirine (n = 28). At baseline and after 12 weeks, both groups performed the Stop-Signal Anticipation Task, which tests reactive and proactive inhibition (indicative of subcortical and cortical functioning, respectively), involving executive functioning, working memory, and attention. Behavior and BOLD fMRI activation levels related to processing speed and attention Z-scores were assessed in 17 pre-defined brain regions. RESULTS: Both groups had comparable patient and clinical characteristics. Reactive inhibition behavioral responses improved for both groups on week 12, with other responses unchanged. Between-group activation did not differ significantly. For reactive inhibition, positive Pearson coefficients were observed for the change in BOLD fMRI activation levels and change in processing speed and attention Z-scores in all 17 regions in participants switched to emtricitabine/tenofovir disoproxil/rilpivirine, whereas in the control group, negative correlation coefficients were observed in 10/17 and 13/17 regions, respectively. No differential pattern was observed for proactive inhibition. CONCLUSION: Potential neural mechanisms underlying cognitive improvement after discontinuing EFV in PLWH were found in subcortical functioning, with our findings suggesting that EFV's effect on attention and processing speed is, at least partially, mediated by reactive inhibition. TRIAL REGISTRATION: Clinicaltrials.gov identifier [NCT02308332].

An exploratory investigation of the CSF metabolic profile of HIV in a South African paediatric cohort using GCxGC-TOF/MS.

INTRODUCTION:  Because cerebrospinal fluid (CSF) samples are difficult to obtain for paediatric HIV, few studies have attempted to profile neurometabolic dysregulation. AIM AND OBJECTIVE: The aim of this exploratory study was to profile the neurometabolic state of CSF from a South African paediatric cohort using GCxGC-TOF/MS. The study included 54 paediatric cases (< 12 years), 42 HIV-negative controls and 12 HIV-positive individuals. RESULTS: The results revealed distinct metabolic alterations in the HIV-infected cohort. In the PLS-DA model, 18 metabolites significantly discriminated between HIV-infected and control groups. In addition, fold-change analysis, Mann-Whitney U tests, and effect size measurements verified these findings. Notably, lactose, myo-inositol, and glycerol, although not significant by p-value alone, demonstrated practical significance based on the effect size. CONCLUSIONS: This study provided valuable insights on the impact of HIV on metabolic pathways, including damage to the gut and blood-brain barrier, disruption of bioenergetics processes, gliosis, and a potential marker for antiretroviral therapy. Nevertheless, the study recognized certain constraints, notably a limited sample size and the absence of a validation cohort. Despite these limitations, the rarity of the study's focus on paediatric HIV research underscores the significance and unique contributions of its findings.

The role of cognitive reserve in mediating HIV-associated neurocognitive disorders in older adults living with-treated HIV in Mbeya, Tanzania: A cross-sectional observational study.

INTRODUCTION: HIV-associated neurocognitive disorders (HAND) are a spectrum of cognitive impairments in chronic HIV infection. HAND is common in sub-Saharan Africa (SSA), despite combination antiretroviral therapy (cART). Older people appear to be at increased risk. It is unknown if cognitive reserve (CR), which is protective in neurodegenerative dementias, protects against HAND. OBJECTIVE: To evaluate the association of CR and risk of HAND in an older cART-treated population in SSA. METHODS: Cross-sectional observational study completed in hospital outpatient clinics in Southwest Tanzania. We assessed HIV-positive participants aged ≥50 years established on cART using a neuropsychological test battery, functional assessment, informant history and depression screen. Control participants were HIV-negative individuals attending chronic disease clinics. We used operationalised Frascati criteria for HAND diagnosis. CR was measured using the Cognitive Reserve Index (CRI) and other proxy measures. RESULTS: The prevalence of HAND was 64.4% (n = 219/343). Lower CRI score [odds ratio (OR) = 0.971, p = 0.009] and less formal education (OR = 4.364, p = 0.026) were independent risk factors for HAND but HIV-severity measures were not. Unemployment and low-skilled manual work were associated with increased risk of HAND in bivariate analysis but not in multivariable analysis. CONCLUSIONS: Higher total CRI score and more formal education appeared to be protective against HAND, in this cohort. Potentially, cognitively and socially stimulating activities and exercise could increase cognitive reserve in later life. Cognitive reserve could possibly be more important than HIV-disease severity in risk of HAND in older people with treated HIV.

Correlation of HIV-Induced Neuroinflammation and Synaptopathy with Impairment of Learning and Memory in Mice with HAND.

Over 38 million people worldwide are living with HIV/AIDS, and more than half of them are affected by HIV-associated neurocognitive disorders (HAND). Such disorders are characterized by chronic neuroinflammation, neurotoxicity, and central nervous system deterioration, which lead to short- or long-term memory loss, cognitive impairment, and motor skill deficits that may show gender disparities. However, the underlying mechanisms remain unclear. Our previous study suggested that HIV-1 infection and viral protein R (Vpr) upregulate the SUR1-TRPM4 channel associated with neuroinflammation, which may contribute to HAND. The present study aimed to explore this relationship in a mouse model of HAND. This study employed the HIV transgenic Tg26 mouse model, comparing Tg26 mice with wildtype mice in various cognitive behavioral and memory tests, including locomotor activity tests, recognition memory tests, and spatial learning and memory tests. The study found that Tg26 mice exhibited impaired cognitive skills and reduced learning abilities compared to wildtype mice, particularly in spatial memory. Interestingly, male Tg26 mice displayed significant differences in spatial memory losses (p < 0.001), while no significant differences were identified in female mice. Consistent with our early results, SUR1-TRPM4 channels were upregulated in Tg26 mice along with glial fibrillary acidic protein (GFAP) and aquaporin 4 (AQP4), consistent with reactive astrocytosis and neuroinflammation. Corresponding reductions in neurosynaptic responses, as indicated by downregulation of Synapsin-1 (SYN1) and Synaptophysin (SYP), suggested synaptopathy as a possible mechanism underlying cognitive and motor skill deficits. In conclusion, our study suggests a possible relationship between SUR1-TRPM4-mediated neuroinflammation and synaptopathy with impairments of learning and memory in mice with HAND. These findings could help to develop new therapeutic strategies for individuals living with HAND.

Depressive-like Behavior Is Accompanied by Prefrontal Cortical Innate Immune Fatigue and Dendritic Spine Losses after HIV-1 Tat and Morphine Exposure.

Opioid use disorder (OUD) and HIV are comorbid epidemics that can increase depression. HIV and the viral protein Tat can directly induce neuronal injury within reward and emotionality brain circuitry, including the prefrontal cortex (PFC). Such damage involves both excitotoxic mechanisms and more indirect pathways through neuroinflammation, both of which can be worsened by opioid co-exposure. To assess whether excitotoxicity and/or neuroinflammation might drive depressive behaviors in persons infected with HIV (PWH) and those who use opioids, male mice were exposed to HIV-1 Tat for eight weeks, given escalating doses of morphine during the last two weeks, and assessed for depressive-like behavior. Tat expression decreased sucrose consumption and adaptability, whereas morphine administration increased chow consumption and exacerbated Tat-induced decreases in nesting and burrowing-activities associated with well-being. Across all treatment groups, depressive-like behavior correlated with increased proinflammatory cytokines in the PFC. Nevertheless, supporting the theory that innate immune responses adapt to chronic Tat exposure, most proinflammatory cytokines were unaffected by Tat or morphine. Further, Tat increased PFC levels of the anti-inflammatory cytokine IL-10, which were exacerbated by morphine administration. Tat, but not morphine, decreased dendritic spine density on layer V pyramidal neurons in the anterior cingulate. Together, our findings suggest that HIV-1 Tat and morphine differentially induce depressive-like behaviors associated with increased neuroinflammation, synaptic losses, and immune fatigue within the PFC.

Patient priority setting in HIV ageing research: exploring the feasibility of community engagement and involvement in Tanzania.

OBJECTIVE: The chronic complications of ageing with HIV are not well studied in sub-Saharan Africa (SSA) where general healthcare resources are limited. We aimed to collaborate with individuals living with HIV aged ≥ 50 years, and community elders (aged ≥ 60 years) living with non-communicable diseases in the Kilimanjaro region of Tanzania in a health research priority-setting exercise. METHODS: We conducted structured workshops based on broad questions to aid discussion and group-based patient priority setting, alongside discussion of the feasibility of future community research engagement. Participant priorities were tallied and ranked to arrive at core priorities from consensus discussion. RESULTS: Thirty older people living with HIV and 30 community elders attended separate priority setting workshops. Both groups reported motivation to participate in, conduct, and oversee future studies. In this resource-limited setting, basic needs such as healthcare access were prioritised much higher than specific HIV-complications or chronic disease. Stigma and social isolation were highly prioritised in those living with HIV. CONCLUSIONS: Community engagement and involvement in HIV and ageing research appears feasible in Tanzania. Ageing and non-communicable disease research should consider the wider context, and lack of basic needs in low-income settings. A greater impact may be achieved with community involvement.

The population in sub-Saharan Africa is ageing. The majority of people living with HIV infection also live in Africa, and they are ageing now that treatment is widely available. Current research on the chronic complications of ageing with and without HIV in sub-Saharan Africa is very limited, meaning that little is known on how to improve symptoms. In this pilot study, researchers from Tanzania and the UK worked with older people living with HIV, and community elders in Tanzania in a health research priority-setting exercise. Thirty older people living with HIV and thirty community elders attended workshops where they listed issues important to them, and then voted for each item as a group. Priorities were ranked in order of importance by adding up the number of votes. We also asked how interested and motivated older people were to work jointly with academic researchers and what might help and support them to do this. Both groups reported that they felt very motivated to participate in, conduct and oversee future research studies. A key finding was that basic needs, such as being able to see a doctor regularly and buying medications, were prioritised much higher than specific HIV-complications or chronic disease. Stigma and social isolation were important issues for older people with HIV. Our pilot findings suggest that meeting basic needs should be a key part of future work on living and ageing with chronic disease in Tanzania. The importance of working with patients and communities is also highlighted.

Sirtuin-2, NAD-Dependent Deacetylase, Is a New Potential Therapeutic Target for HIV-1 Infection and HIV-Related Neurological Dysfunction.

The implementation and access to combined antiretroviral treatment (cART) have dramatically improved the quality of life of people living with HIV (PLWH). However, some comorbidities, such as neurological disorders associated with HIV infection still represent a serious clinical challenge. Soluble factors in plasma that are associated with control of HIV replication and neurological dysfunction could serve as early biomarkers and as new therapeutic targets for this comorbidity. We used a customized antibody array for determination of blood plasma factors in 40 untreated PLWH with different levels of viremia and found sirtuin-2 (SIRT2), an NAD-dependent deacetylase, to be strongly associated with elevated viral loads and HIV provirus levels, as well as with markers of neurological damage (a-synuclein [SNCA], brain-derived neurotrophic factor [BDNF], microtubule-associated protein tau [MAPT], and neurofilament light protein [NFL]). Also, longitudinal analysis in HIV-infected individuals with immediate (n = 9) or delayed initiation (n = 10) of cART revealed that after 1 year on cART, SIRT2 plasma levels differed between both groups and correlated inversely with brain orbitofrontal cortex involution. Furthermore, targeting SIRT2 with specific small-molecule inhibitors in in vitro systems using J-LAT A2 and primary glial cells led to diminished HIV replication and virus reactivation from latency. Our data thus identify SIRT2 as a novel biomarker of uncontrolled HIV infection, with potential impact on neurological dysfunction and offers a new therapeutic target for HIV treatment and cure. IMPORTANCE Neurocognitive disorders are frequently reported in people living with HIV (PLWH) even with the introduction of combined antiretroviral treatment (cART). To identify biomarkers and potential therapeutic tools to target HIV infection in peripheral blood and in the central nervous system (CNS), plasma proteomics were applied in untreated chronic HIV-infected individuals with different levels of virus control. High plasma levels of sirtuin-2 (SIRT2), an NAD+ deacetylase, were detected in uncontrolled HIV infection and were strongly associated with plasma viral load and proviral levels. In parallel, SIRT2 levels in the peripheral blood and CNS were associated with markers of neurological damage and brain involution and were more pronounced in individuals who initiated cART later in infection. In vitro infection experiments using specific SIRT2 inhibitors suggest that specific targeting of SIRT2 could offer new therapeutic treatment options for HIV infections and their associated neurological dysfunction.

Declining Prevalence of Human Immunodeficiency Virus (HIV)-Associated Neurocognitive Disorders in Recent Years and Associated Factors in a Large Cohort of Antiretroviral Therapy-Treated Individuals With HIV.

BACKGROUND: HIV-associated neurocognitive disorders (HAND) have been suggested as persistent even with effective antiretroviral therapy (ART). Aims were to evaluate HAND prevalence and associated factors, in a large cohort of people-with-HIV (PWH). METHODS: ART-treated PWH, underwent a neuropsychological examination through a battery of 12 tests exploring 5 different domains, between 2009 and 2020, were included in this cross-sectional analysis. HAND were classified according to Frascati's criteria. Participants were defined as complaining or not-complaining if a cognitive complaint was reported or not. Chi-square for trend and multivariable logistic regression were fitted. RESULTS: Overall, 1424 PWH were enrolled during four three-years periods. HAND prevalence was 24%; among complainers (572/1424), it was 38%, higher than among not-complainers (15%). Over the study period, a decreasing HAND prevalence was found in the entire population (P < 0.001) and in complaining (P < 0.001); in not-complaining it remained stable (P = 0.182). Factors associated with HAND were older age, lower educational level, lower current CD4+ T-cell count and HCV co-infection. Compared to nonnucleoside reverse transcriptase inhibitors, receiving dual and integrase strand transfer inhibitor (INSTI)-based therapies was associated with a decreased risk of HAND, as well as being tested in more recent years. CONCLUSIONS: In this large cohort of ART-treated PWH, mostly virologically suppressed, a remarkable decreasing HAND prevalence was observed. Besides HIV- and patient-related factors, the reduced risk of HAND found with dual and INSTI-based regimens along with a more recent ART initiation, could suggest a potential role of new treatment strategies in this decline, due to their greater virologic efficacy and better tolerability.

Neurodegeneration Within the Amygdala Is Differentially Induced by Opioid and HIV-1 Tat Exposure.

Opioid use disorder (OUD) is a critical problem that contributes to the spread of HIV and may intrinsically worsen neuroHIV. Despite the advent of combined antiretroviral therapies (cART), about half of persons infected with HIV (PWH) experience cognitive and emotional deficits that can be exacerbated by opioid abuse. HIV-1 Tat is expressed in the central nervous system (CNS) of PWH on cART and is thought to contribute to neuroHIV. The amygdala regulates emotion and memories associated with fear and stress and is important in addiction behavior. Notwithstanding its importance in emotional saliency, the effects of HIV and opioids in the amygdala are underexplored. To assess Tat- and morphine-induced neuropathology within the amygdala, male Tat transgenic mice were exposed to Tat for 8 weeks and administered saline and/or escalating doses of morphine twice daily (s.c.) during the last 2 weeks of Tat exposure. Eight weeks of Tat exposure decreased the acoustic startle response and the dendritic spine density in the basolateral amygdala, but not the central nucleus of the amygdala. In contrast, repeated exposure to morphine alone, but not Tat, increased the acoustic startle response and whole amygdalar levels of amyloid-ß (Aß) monomers and oligomers and tau phosphorylation at Ser396, but not neurofilament light chain levels. Co-exposure to Tat and morphine decreased habituation and prepulse inhibition to the acoustic startle response and potentiated the morphine-induced increase in Aß monomers. Together, our findings indicate that sustained Tat and morphine exposure differentially promote synaptodendritic degeneration within the amygdala and alter sensorimotor processing.

Validation of the National Institute of Health Toolbox Cognition Battery (NIHTB-CB) in Children and Adolescents with and without HIV Infection in Lusaka, Zambia.

The objective of this study was to validate the NIH Toolbox Cognition Battery (NIHTB-CB) in Zambian children with and without HIV-infection. Children living with HIV and HIV-exposed, uninfected (HEU) children completed traditional neuropsychological and NIHTB-CB tasks. Using pairwise correlation and a linear regression model we measured associations between traditional measure composite scores and parental ratings of children's abilities, and NIHTB-CB scores. A Receiver Operating Characteristic (ROC) curve was developed to identify participants with impairment. 389 children, 8-17 years old participated. NIHTB-CB and traditional measures converged well as a whole and when comparing analogous individual tests across the two batteries. The NIHTB-CB composite score discriminated between the groups and was positively associated with external criteria for cognitive function: parental ratings of intelligence and school performance. Some English vocabulary and/or an unfamiliar cultural context presented challenges. NIHTB-CB was associated with children's everyday cognitive abilities, though future use may require linguistic and cultural adaptation.

Prodrug Therapies for Infectious and Neurodegenerative Diseases.

Prodrugs are bioreversible drug derivatives which are metabolized into a pharmacologically active drug following chemical or enzymatic modification. This approach is designed to overcome several obstacles that are faced by the parent drug in physiological conditions that include rapid drug metabolism, poor solubility, permeability, and suboptimal pharmacokinetic and pharmacodynamic profiles. These suboptimal physicochemical features can lead to rapid drug elimination, systemic toxicities, and limited drug-targeting to disease-affected tissue. Improving upon these properties can be accomplished by a prodrug design that includes the careful choosing of the promoiety, the linker, the prodrug synthesis, and targeting decorations. We now provide an overview of recent developments and applications of prodrugs for treating neurodegenerative, inflammatory, and infectious diseases. Disease interplay reflects that microbial infections and consequent inflammation affects neurodegenerative diseases and vice versa, independent of aging. Given the high prevalence, personal, social, and economic burden of both infectious and neurodegenerative disorders, therapeutic improvements are immediately needed. Prodrugs are an important, and might be said a critical tool, in providing an avenue for effective drug therapy.

Cardio-ankle vascular index of increased arterial wall stiffness is associated with neurocognitive impairment in well-controlled HIV.

OBJECTIVES: HIV-associated neurocognitive disorders (HAND) remain prevalent in people living with HIV (PLWH) despite widespread use of combined antiretroviral therapy (ART). Vascular disease contributes to the pathogenesis of HAND, but traditional vascular risk factors do not fully explain the relation between vascular disease and HAND. A more direct measure of vascular dysfunction is needed. This cross-sectional study tested whether the cardio-ankle vascular index (CAVI), a novel method to assess arterial stiffness, is associated with HAND among PLWH. METHODS: Participants included 75 non-diabetic adults with well-controlled HIV from an outpatient HIV clinic. We assessed the relation between CAVI and neurocognitive impairment (NCI). The latter was primarily characterized by the Frascati criteria and secondarily (post hoc) using the Global Deficit Score (GDS). Logistic regression models tested whether high CAVI (≥ 8) was independently associated with NCI when controlling for potential confounders. RESULTS: Participants (Mage  = 45.6 ± 8.3 years; 30.1% male) had few traditional cardiovascular disease (CVD) risk factors (hypertension, n = 7; dyslipidaemia, n = 34; body mass index ≥ 25 kg/m2 , n = 12; smoking history, n = 13; 2.2% mean 10-year risk of CVD or stroke). Twelve (16%) participants had high CAVI, which was independently associated with meeting Frascati criteria for NCI [n = 39, odds ratio (OR) = 7.6, p = 0.04], accounting for age, education, gender, income, CD4 nadir, recent CD4 and traditional CVD risk factors. High CAVI was also associated with NCI as reflected by higher GDS (OR = 17.4, p = 0.02). CONCLUSIONS: Cardio-ankle vascular index is a promising measure of vascular dysfunction that may be independently associated with NCI in relatively healthy PLWH. Larger studies should test the utility of CAVI in predicting NCI/decline in PLWH.

Telomere Length Shortening in Microglia: Implication for Accelerated Senescence and Neurocognitive Deficits in HIV.

The widespread use of combination antiretroviral therapy (cART) has led to the accelerated aging of the HIV-infected population, and these patients continue to have a range of mild to moderate HIV-associated neurocognitive disorders (HAND). Infection results in altered mitochondrial function. The HIV-1 viral protein Tat significantly alters mtDNA content and enhances oxidative stress in immune cells. Microglia are the immune cells of the central nervous system (CNS) that exhibit a significant mitotic potential and are thus susceptible to telomere shortening. HIV disrupts the normal interplay between microglia and neurons, thereby inducing neurodegeneration. HIV cART contributes to the inhibition of telomerase activity and premature telomere shortening in activated peripheral blood mononuclear cells (PBMC). However, limited information is available on the effect of cART on telomere length (TL) in microglia. Although it is well established that telomere shortening induces cell senescence and contributes to the development of age-related neuro-pathologies, the effect of HIV-Tat on telomere length in human microglial cells and its potential contribution to HAND are not well understood. It is speculated that in HAND intrinsic molecular mechanisms that control energy production underlie microglia-mediated neuronal injury. TL, telomerase and mtDNA expression were quantified in microglial cells using real time PCR. Cellular energetics were measured using the Seahorse assay. The changes in mitochondrial function were examined by Raman Spectroscopy. We have also examined TL in the PBMC obtained from HIV-1 infected rapid progressors (RP) on cART and those who were cART naïve, and observed a significant decrease in telomere length in RP on cART as compared to RP's who were cART naïve. We observed a significant decrease in telomerase activity, telomere length and mitochondrial function, and an increase in oxidative stress in human microglial cells treated with HIV Tat. Neurocognitive impairment in HIV disease may in part be due to accelerated neuro-pathogenesis in microglial cells, which is attributable to increased oxidative stress and mitochondrial dysfunction.

Deep Phenotyping of HIV Neurocognitive Complications Among Individuals Residing in High-Income Countries.

People living with HIV (PLWH) residing in high-income countries (HICs) are, in theory, well positioned to benefit from clinical care strategies that predict optimal neurocognitive and neuropsychiatric outcomes. However, there is substantial inter-individual variability in access to clinical care, prevalence of co-occurring risk factors, and comorbid health conditions that represent barriers to achieving the full potential of antiretroviral therapy (ART). Complex interactions between these variables translate into heterogeneity in HIV clinical phenotypes, including abnormalities in brain structure and function. The growing population of PLWH in HICs who are now reaching advanced age introduces additional causal pathways of neurocognitive variability among PLWH receiving ART. These patterns foreshadow trends expected to develop globally in response to increased access to ART. This chapter reviews the combination of highly dimensional risk factors for neurocognitive complications among PLWH residing in HICs. We begin with a brief description of the neuropathological, neuroimaging, and neurocognitive signatures of HIV, followed by a summary of controversies regarding the clinical presentation of HIV-associated neurocognitive disorders (HAND), including putative synergies between HIV disease dynamics and advanced age. Finally, we introduce innovative research strategies that have potential to advance the existing conceptual framework of HAND and, ideally, catalyze the development and of clinical interventions needed to achieve HIV treatment and eradication efforts.

HIV-Associated Neurocognitive Impairment Knowledge and Current Practices: A Survey of Frontline Healthcare Workers in South Africa.

Neurocognitive impairment (NCI) associated with the human immunodeficiency virus (HIV) remains prevalent amongst people living with HIV. Testing for HIV-associated NCI in routine clinical care is limited in South Africa and reasons for this are unclear. We conducted an online survey amongst healthcare workers (HCW) to assess HIV-associated NCI knowledge and current practices. The final sample included four hundred surveys (n=400). Chi-square analyses were used to explore HCW knowledge of HIV-associated NCI and screening tools. One-way ANOVA was used to compare mean responses between HCW categories. We observed low awareness of HIV-associated NCI terminology and screening tools. HCW seldom suspected NCI among patients and screening practices were uncommon. Referrals for further NCI investigations were never requested. HCW expressed a desire to receive further training to identify HIV associated NCI. The current study highlights the context of HIV-associated NCI knowledge and practices among front-line HIV HCW in resource-limited settings.

Metabolic Syndrome and Cardiovascular Disease Impacts on the Pathophysiology and Phenotype of HIV-Associated Neurocognitive Disorders.

Evidence from epidemiological studies on the general population suggests that midlife cardiovascular disease (CVD) and/or metabolic syndrome (MetS) are associated with an increased risk of cognitive impairment and dementia later in life. In the modern combined antiretroviral therapy (cART) era, as in the general population, CVD and MetS were strongly and independently associated with poorer cognitive performances of sustained immunovirologically controlled persons living with human immunodeficiency viruses (PLHIVs). Those findings suggest that CV/metabolic comorbidities could be implicated in the pathogenesis of HIV-associated neurocognitive disorders (HAND) and might be more important than factors related to HIV infection or its treatment, markers of immunocompetence, or virus replication. The association between CVD/MetS and cognition decline is driven by still not well-understood mechanisms, but risk might well be the consequence of increased brain inflammation and vascular changes, notably cerebral small-vessel disease. In this review, we highlight the correspondences observed between the findings concerning CVD and MetS in the general population and virus-suppressed cART-treated PLHIVs to evaluate the real brain-aging processes. Indeed, incomplete HIV control mainly reflects HIV-induced brain damage described during the first decades of the pandemic. Given the growing support that CVD and MetS are associated with HAND, it is crucial to improve early detection and assure appropriate management of these conditions.

Assessing HIV provider knowledge, screening practices, and training needs for HIV-associated neurocognitive disorders. A short report.

Management of HIV-associated neurocognitive disorders (HAND) is becoming increasingly important with HIV-positive people living normal life spans. We aimed to establish the level of HAND awareness among doctor and nurse occupational health practitioners, screening used to detect impairment, factors limiting screening for HAND, and training needs. One-hundred-and-five members of the nursing and physician professional societies for occupational health practitioners in South Africa and Occupational Health Departments at five South African universities responded to an email invitation to complete an online survey addressing demographics, HAND knowledge, screeners being used to screen for HAND and related training needs. While 80% had heard of HAND, few (13.3%) were aware of the Frascati criteria. Only 2% had received training addressing HAND; 11.4% screened for HAND; 45.7% did not know what screening tool to us; 80% preferred spending <15 min on screening. The largest obstacle to screening was lack of expertise (77.1%) but 77.3% thought it important to screen for HAND. 94.3% wanted screening training. Health providers are poorly informed about HAND and lack expertise and tools to screen for HAND in their treatment programs. While few had relevant training, they recognize the importance of screening for HAND in the workplace and desire training.

HIV-1 Vpr-Induced Proinflammatory Response and Apoptosis Are Mediated through the Sur1-Trpm4 Channel in Astrocytes.

Successful treatment of HIV-infected patients with combinational antiretroviral therapies (cART) can now prolong patients' lives to nearly normal life spans. However, the new challenge faced by many of those HIV-infected patients is chronic neuroinflammation and neurotoxicity that often leads to HIV-associated neurocognitive disorders (HAND). However, the mechanism of neuropathogenesis underlying HAND, especially in those who are under cART, is not well understood. HAND is typically characterized by HIV-mediated glial neuroinflammation and neurotoxicity. However, the severity of HAND does not always correlate with HIV-1 viral load but, rather, with the extent of glial activation, suggesting that other HIV-associated factors might contribute to HAND. HIV-1 viral protein R (Vpr) could be one of those viral factors because of its association with neuroinflammation and neurotoxicity. The objective of this study was to delineate the specific roles of HIV-1 infection and Vpr in the activation of neuroinflammation and neurotoxicity, and the possible relationships with the Sur1-Trpm4 channel that contributes to neuroinflammation and neuronal death. Here, we show that HIV-1 expression correlates with activation of proinflammatory markers (TLR4, TNF-α, and NF-κB) and the Sur1-Trpm4 channel in astrocytes of HIV-infected postmortem human and transgenic Tg26 mouse brain tissues. We further show that Vpr alone activates the same set of proinflammatory markers and Sur1 in a glioblastoma SNB19 cell line that is accompanied by apoptosis. The Sur1 inhibitor glibenclamide significantly reduced Vpr-induced apoptosis. Together, our data suggest that HIV-1 Vpr-induced proinflammatory response and apoptosis are mediated at least in part through the Sur1-Trpm4 channel in astrocytes.IMPORTANCE Effective antiretroviral therapies can now prolong patients' lives to nearly normal life span. The current challenge faced by many HIV-infected patients is chronic neuroinflammation and neurotoxicity that contributes to HIV-associated neurocognitive disorders (HAND). We show here that the expression of HIV-1 infection and Vpr correlates with the activation of proinflammatory markers (Toll-like receptor 4 [TLR4], tumor necrosis factor alpha [TNF-α], and NF-κB) and the sulfonylurea receptor 1 (Sur1)-transient receptor potential melastatin 4 (Trpm4) channel in astrocytes of brain tissues. We further show that an FDA-approved Sur1 inhibitory drug called glibenclamide significantly ameliorates apoptotic astrocytic cell death caused by HIV-1 Vpr, which could potentially open the possibility of repurposing glibenclamide for treating HAND.