HIV-1-associated neurocognitive disorder: epidemiology, pathogenesis, diagnosis, and treatment

Exploring socio-economic dimensions in HIV research: a comprehensive bibliometric analysis (1992-2024)

The socio-economic burden of HIV infection remains a critical global health concern. This study was conducted to perform a comprehensive bibliometric analysis of the socio-economic burden of HIV infection, highlighting research trends, collaboration networks, and the evolving focus on social determinants of health over the past 32 years. A systematic search was conducted in Scopus and Web of Science Core Collection databases, covering publications from 1992 to 2024. The analysis was performed using RStudio and Biblioshiny, focusing on 1,054 studies from 422 publications. This study revealed a steady annual growth rate of 16.72% in publications on the socio-economic burden of HIV from 1992 to 2024, with the USA and Canada leading in contributions. The University of Toronto emerged as the top institution, while 'social determinants of health' and 'HIV infections' were identified as pivotal research themes. Collaboration networks were predominantly among high-income countries, with limited engagement from high-burden regions like sub-Saharan Africa. Key journals, such as AIDS and Behavior, were identified as central to advancing the field. Thematic analysis highlighted a shift from biomedical to socio-economic factors, emphasizing the need for equitable global collaboration and research addressing disparities in HIV management. This comprehensive analysis provides valuable insights into the evolving landscape of HIV socio-economic burden research, emphasizing the need for increased collaboration with high-burden regions and a continued focus on addressing social determinants of health in HIV management.

Epilepsy in low- to middle-income countries

PURPOSE OF REVIEW

Epilepsy disproportionately affects those in low- and middle-income countries (LMICs) where diagnostic and treatment gaps persist.We highlight key recent developments and showcase practical opportunities to improve epilepsy care in resource limited settings.

RECENT FINDINGS

In LMICs, cultural, socioeconomic and infrastructural factors drive the epilepsy treatment gap. Robust implementation of the WHO Intersectoral Global Action Plan (WHO IGAP) and Mental Health Gap Action Program (mhGAP), for example, will reduce the epilepsy education gap. Engaging traditional healers and other key community leaders should lessen stigma. The Epilepsy Diagnostic Companion, a culture specific tool that helps identify convulsive seizures, can expedite epilepsy diagnosis at primary care level. Novel, robust 3-D printable EEG headsets prototypes that can be deployed in remote rural communities have been piloted with encouraging results. Levetiracetam has been added to the WHO Essential Medicines List (EML), paving way to safer, less teratogenic antiseizure medications (ASMs). Epilepsy surgery programs in carefully selected patients potentially offer cheap, effective and potentially curative treatments, including in LMICs.

SUMMARY

Apps, EEG prototypes, better access to ASMs and implementation of WHO iGAP offer current, tangible opportunities to improve epilepsy care in LMICs. Bidirectional learning must be facilitated to also help hard to reach communities in high-income settings.

HIV-associated neurocognitive disorders (HAND): Optimal diagnosis, antiviral therapy, pharmacological treatment, management, and future scopes

In the context of HIV infection, HIV-associated neurocognitive disorders (HAND) have become a serious concern. An extensive summary of the diagnosis, care, and mental health consequences related to HAND is given in this article. The diagnosis of HAND entails a multimodal approach that includes neuroimaging, cognition tests, and clinical examinations. Numerous screening instruments and standardized evaluations have been created to support the early identification and tracking of HAND. Appropriate actions and individualized treatment plans are made possible by prompt diagnosis. A multidisciplinary approach is used in the treatment of HAND, aiming to address various elements of cognitive impairment. The main stream of treatment is still antiretroviral medication (ART), which successfully lowers viral loads and stops further neurocognitive deterioration. Adjunctive treatments are essential for treating cognitive symptoms and improving overall quality of life. These therapies include cognitive rehabilitation, pharmaceutical interventions, and psychological support. Our knowledge of the pathophysiology of HAND has improved with the identification of the inflammatory milieu and persistent viral persistence in the central nervous system (CNS), which has also aided in the creation of biomarkers for CNS illness. Although biomarkers show inflammation, neuronal damage, and monocyte activity, their clinical use is still restricted. Although new techniques to treating HAND have been developed as a result of a better knowledge of pathogenic processes, the best course of action is still unknown.

Development of research on HIV-associated neurocognitive disorder and emerging trends: a visualization analysis via CiteSpace

Background

In the combination antiretroviral therapy era, HIV-associated neurocognitive disorder (HAND) is still widespread among HIV-infected individuals. However, there is no effective treatment for HAND, and the exact pathogenic mechanism of HAND remains unknown. This paper aims to provide a reference for further exploration in the field of HAND research.

Methods

We used CiteSpace software to collect 3057 articles related to HAND in the Web of Science Core Collection for comprehensive analysis. Betweenness centrality, count, and burst values were used as indicators in the visualization analysis, aiming to predict future new directions and cutting-edge trends.

Results

The last decade has been the peak period of HAND research, with the most prominent contributions by authors, countries, and institutions being Grant, Igor (135), the USA (2211), and the University of California System (758), respectively. The most frequently cited article is "HIV-associated neurocognitive disorders persist in the area of potent antiretroviral therapy: CHARTER Study." The hotspots in this field are "neurocognitive impairment," "central nervous system," "cerebrospinal fluid," "HIV-1 tat," "SIV," "inflammation," "infection," and "pathogenesis." The current research direction of HAND is focused on exploring the pathogenic mechanism underlying HIV-associated neurocognitive impairment and potential therapeutic targets.

Conclusion

This study provides a bibliometric visualization of HAND-related literature to gain insight into the development and frontiers of this research field. The study also provides scholars with detailed references and identifies future research directions to better promote the development of this field of research.

Influence of plasma exosomes from women living with HIV Stratified by HAND on monocyte subpopulations from healthy women without HIV

The role of plasma exosomes from people living with HIV (PLWH) with HAND in the phenotypic profile of uninfected monocytes remains unknown. We hypothesized that these exosomes influence the CD14/CD16 phenotypical profile of uninfected monocytes in a time-dependent manner. Exosomes were collected via ultracentrifugation from the plasma of women living with HIV (WLWH) and healthy controls stratified according to their cognition into normal cognition (NC) or symptomatic neurocognitive impairment (SNI) groups. Monocyte subsets were identified via flow cytometry by using anti-CD14 and anti-CD16 fluorescent antibodies. Exosome uptake and changes in the percentages of monocyte subpopulations were analyzed from 1 to 24 h. The following results were obtained. (1) The uptake of HIV-negative exosomes by total uninfected monocytes was observed at 24 h, whereas the uptake of HIV-positive exosomes was observed at an earlier time point at 6 h. (2) HIV-positive exosomes significantly decreased the percentage of classical monocytes and increased intermediate and nonclassical monocytes at 24 h. (3) The uptake of NC exosomes was observed at an early time point at 6 h compared with SNI in all of the monocyte subsets. (4) Higher percentages of monocyte subsets were observed when cells were exposed to NC exosomes at 1 h, 6 h, or 24 h than when monocytes were exposed to exosomes from SNI patients. Our findings may help to identify new targets and molecular mechanisms that are involved in the pathogenesis of HAND.

Importance of Modulating Kynurenic Acid Metabolism-Approaches for the Treatment of Dementia

In this article, we focus on kynurenic acid metabolism in neuropsychiatric disorders and the biochemical processes involved in memory and cognitive impairment, followed by different approaches in the fight against dementia. Kynurenic acid-a biochemical part of L-tryptophan catabolism-is synthesized from L-kynurenine by kynurenine aminotransferases. Experimental pharmacological studies have shown that elevated levels of kynurenic acid in the brain are associated with impaired learning and that lowering kynurenic acid levels can improve these symptoms. The discovery of new compounds with the ability to block kynurenine aminotransferases opens new therapeutic avenues for the treatment of memory impairment and dementia. The newly developed Helix pomatia snail model of memory can be used for the assessment of novel pharmacological approaches. Dietary supplementation with natural molecular/herbal extracts, exercise, and physical activity have significant impacts on endogenous pharmacology by reducing kynurenic acid synthesis, and these factors are likely to significantly modulate steady-state biological conditions and delay the negative consequences of aging, including the onset of pathological processes.

PKR Inhibitor C16 Regulates HIV-gp120 Induced Neuronal Injury and Cognitive Impairment in Vivo and in Vitro Models

To study the neuronal protective effect and its potential mechanism of C16 against gp120-induced cognitive impairment in vitro and in vivo. The NORT method was used to evaluate the short-term memory abilities of rats, the morphological changes in hippocampus were observed by Nissl staining. Cell viability and damage degree were detected by MTT and LDH. The cell living/apoptosis status of PC12 cells was determined by AO/EB double staining and the relative mRNA expressions of PKR, IRE1α, JNK, GRP78, and CHOP were detected by RT-qPCR. In comparison with the gp120 + Memantine and gp120 + C16 groups, the rats in the gp120 group showed a significantly decreased discrimination index (P < 0.001), with disordered CA1 region cells and reduced neuron numbers. AO/EB double staining revealed morphological changes in the gp120 and NMDA groups, while cells in the gp120 + C16 and NMDA + C16 groups resembled the control group. And C16 can significantly down-regulate the mRNA expression levels of PKR, IRE1α, JNK, GRP78, and CHOP. (P < 0.05). C16 can reduce the cognitive impairment stimulated by gp120 or NMDA, the protective mechanism may be correlated with inhibiting the upregulation of PKR/IRE1α/JNK pathway and suppressing apoptosis induced by downstream proteins GRP78 and CHOP.

HIV-TAT dysregulates microglial lipid metabolism through SREBP2/miR-124 axis: Implication of lipid droplet accumulation microglia in NeuroHIV

Chronic HIV infection can dysregulate lipid/cholesterol metabolism in the peripheral system, contributing to the higher incidences of diabetes and atherosclerosis in HIV (+) individuals. Recently, accumulating evidence indicate that HIV proteins can also dysregulate lipid/cholesterol metabolism in the brain and such dysregulation could be linked with the pathogenesis of HIV-associated neurological disorders (HAND)/NeuroHIV. To further characterize the association between lipid/cholesterol metabolism and HAND, we employed HIV-inducible transactivator of transcription (iTAT) and control mice to compare their brain lipid profiles. Our results reveal that HIV-iTAT mice possess dysregulated lipid profiles and have increased numbers of lipid droplets (LDs) accumulation microglia (LDAM) in the brains. HIV protein TAT can upregulate LDs formation through enhancing the lipid/cholesterol synthesis in vitro. Mechanistically, HIV-TAT increases the expression of sterol regulatory element-binding protein 2 (SREBP2) through microRNA-124 downregulation. Cholesterol synthesis inhibition can block HIV-TAT-mediated NLRP3 inflammasome activation and microglial activation in vitro as well as mitigate aging-related behavioral impairment and memory deficiency in HIV-iTAT mice. Taken together, our results indicate an inherent role of lipid metabolism and LDAM in the pathogenesis of NeuroHIV (immunometabolism). These findings suggest that LDAM reversal through modulating lipid/cholesterol metabolism could be a novel therapeutic target for ameliorating NeuroHIV symptoms in chronic HIV (+) individuals.

p62 Binding to Protein Kinase C Regulates HIV-1 gp120 V3 Loop Induced Microglial Inflammation

The main pathogenic mechanism of HIV-associated neurocognitive disorders (HAND) is neuronal apoptosis induced by inflammatory mediators, in which microglial inflammation plays a crucial role. However, the exact pathogenic mechanism remains unclear. Previous studies have shown that the HIV-1 gp120 V3 loop can trigger inflammation in CHME-5 microglia. p62 is a post-translational modified multidomain protein that is involved in the regulation of autophagy and is closely related to neuroinflammation. In this study, we found that p62 knockout down-regulated the expression of MCP-1, IL-6 and COX-2, and improved the inflammation of HIV-1 gp120 V3 loop induced microglia, while overexpression of p62 up-regulated the expression of MCP-1, IL-6 and COX-2, and promoted the inflammation of microglia. In addition, protein kinase C (PKC) knockout down-regulated the expression of MCP-1, IL-6 and COX-2 and inhibited the activation of IKK/ NF-κ B pathway, while tumor necrosis factor receptor-associated factor 6 (TRAF6) knockout had no significant effect on the expression of MCP-1, IL-6 and COX-2. Co-immunoprecipitation showed that p62 was bound and interacted with PKC. Inhibition of IKK/ NF-κ B pathway can down-regulate the expression of MCP-1, IL-6 and COX-2, and improve the inflammatory response of microglia. Our research further found that inhibition of IKK/ NF-κ B can decrease the expression of Caspase-3 and reduce the apoptosis of neurons in the co-culture of CHME-5 microglia and primary mouse neurons. The results of this study suggest that HIV-1 gp120 V3 loop induced CHME-5 microglial inflammation may be activated by the direct binding of p62 and PKC through the IKK/ NF-κ B signaling pathway, and these findings provide an important reference for the prevention and treatment of HAND.

Application status and prospects of multimodal EEG-fMRI in HIV-associated neurocognitive disorders

HIV-associated neurocognitive disorders (HAND) are one of the common complications in people living with HIV (PLWH), which can affect their attention, working memory, and other related cognitive functions. With the widespread use of combination antiretroviral therapy (cART), the incidence of HAND has declined. However, HAND is still an important complication of HIV, which not only affects the quality of life of patients but also affects their adherence to HIV treatment. Its diagnosis mainly relies on neurocognitive tests, which have a certain degree of subjectivity, making it difficult to diagnose and classify HAND accurately, and there is an urgent need to explore more sensitive biomarkers. Multimodal brain imaging has seen a surge in recent years with simultaneous EEG-fMRI being at the forefront of cognitive multimodal neuroimaging. It is a complementary fusion technique that effectively combines the high spatial resolution of fMRI with the high temporal resolution of EEG, compensating for the shortcomings of a single technique and providing a new method for studying cognitive function. It is expected to reveal the underlying mechanisms of HAND and provide high spatiotemporal warning biomarkers of HAND, which will provide a new perspective for the early diagnosis and treatment of HAND and contribute to the improvement of patient prognosis.

Impact of HIV-1 tat protein on methamphetamine-induced inhibition of vesicular monoamine transporter2-mediated dopamine transport and methamphetamine conditioned place preference in HIV-1 tat transgenic mice

Perturbation of dopamine transmission has been implicated as a contributing factor in HIV-1 associated neurocognitive disorders with concurrent methamphetamine (METH) abuse. We have demonstrated that the HIV-1 protein, transactivator of transcription (Tat), decreases dopamine transport through inhibition of vesicular monoamine transporter2 (VMAT2). This study determined the effects of Tat protein on METH-inhibited VMAT2 function and METH-conditioned place preference (CPP). In vitro exposure of isolated mouse whole brain vesicles to recombinant Tat1-86 or METH displayed a concentration-dependent inhibition of the vesicular [3H]Dopamine uptake, in which a combination of Tat and METH induced a greater reduction of dopamine uptake compared to Tat or METH alone. In vivo, the maximal velocity (Vmax) of vesicular [3H]Dopamine uptake was decreased in inducible Tat transgenic (iTat-tg) mice harvested after treatment with either 21-day doxycycline (Dox) or 14-day METH (3 mg/kg, i.p., daily), whereas these mice treated with both Dox and METH displayed an additive reduction of the Vmax compared to either Tat or METH alone. Moreover, Dox-induced Tat expression increased METH-CPP in an exposure-dependent manner, with iTat-tg mice demonstrating a 2.3-fold potentiation of METH-CPP compared with Tat null control mice upon administration of Dox for 14 days. Furthermore, a 7-day administration of Dox reinstated extinguished METH-CPP. Collectively, these results suggest a synergistic effect of Tat protein and METH on inhibition of VMAT2-mediated DA transport, potentially contributing to potentiation of METH-CPP in iTat-tg mice.

Substance use moderates relationships between apolipoprotein E genotype, hepatitis C, cognition, and depression in Miami Adult Studies on HIV (MASH) participants

The impact of APOE on HIV and HCV disease course, cognition, and memory has been understudied in minoritized populations. This study examined whether scores on cognition and depression measures differed by APOE ε4 carrier status while considering HCV and HIV seropositivity and whether these measures were moderated by substance use. A retrospective analysis examined cognitive and psychological data from participants (n = 493) in the Miami Adult Studies on HIV (MASH) cohort. APOE genotyping was performed on banked blood samples. Multiple linear regression was employed to examine differences across participants living with and without HIV and/or HCV and by APOE ε4 genotype. APOE ε4 carriers living with HCV who used cannabis had higher depression scores than non-ε4 carriers, while nonusers had fewer depressive symptoms. APOE ε4 carriers living with HCV had better cognition scores after adjusting for cocaine, opiate, and cannabis use than non-ε4 carriers. Scores on cognitive and depression measures did not differ between APOE ε4 carriers and non-ε4 carriers in participants living with HIV, and substance use did not moderate this relationship. This study was the first of its kind to examine substance use as a moderator for cognition and depression among individuals with HIV and/or HCV stratified by APOE genotype. Findings support further research evaluating the frequency and duration of 1) domains of cognitive functioning impacted by APOE genotype relevant to substance use and 2) the influence of substance use on cognitive and depressive outcomes among adults living with HIV and HCV, HIV, or HCV.

The incidence of symptomatic CSF viral escape in patients on antiretroviral therapy in western India: a retrospective cohort study

Antiretroviral treatment (ART) effectively suppresses viral loads in both plasma and cerebrospinal fluid (CSF). Patients with discordant plasma and CSF viral loads may experience chronic-progressive or fluctuating neurocognitive dysfunctions. This study examined the incidence of symptomatic CSF viral escape (CSFVE) in patients receiving ART. This retrospective cohort study was conducted between 2000 and 2023. The primary outcome measure was the incidence of symptomatic CSFVE. Nonparametric Mann-Whitney U and Fisher exact/χ 2 tests were applied for continuous and categorical variables, respectively. The cumulative incidence function with Gray's test was used to compare the incidence of CSFVE across the treatment regimens. During the study period, 52 of the 8415 patients were diagnosed with CSFVE. The median duration of HIV diagnosis in patients with CSF VE was 150 (12-288) months, with a median nadir CD4 + T-cell count 96.5 (13-601 cells/L)], and 75% of the patients were on a ritonavir-boosted protease inhibitor (PI/r) regimen. The cumulative incidence of symptomatic CSFVE at a follow-up of 14 years was 1% (95% CI, 0-1%). PI/r (HR 34.73; 95% CI 13.5 to 89.4; p < 0.001) and integrase strand transfer inhibitor (INSTI) (HR 3.42; 95% CI 1.94 to 6.02; p < 0.001) regimens were significantly more likely to be associated with CSFVE than the Non-nucleoside reverse transcriptase inhibitors (NNRTIs) regimens. NNRTIs had the lowest risk of CSFVE compared to the PI/r and INSTI regimens. A rapid and complete recovery is possible with symptomatic CSFVE if it is diagnosed and treated early.

Memory complaints after COVID-19: a potential indicator of primary cognitive impairment or a correlate of psychiatric symptoms?

Cognitive impairment and symptoms of psychiatric disorders have been reported frequently as features of post-acute sequelae of SARS-CoV-2 infection. This study aims to investigate subjective memory complaints in COVID-19 survivors and determine if these are more strongly associated with objective cognitive impairment related to sequelae of SARS-CoV-2 infection or with symptoms of psychiatric conditions. A total of 608 COVID-19 survivors were evaluated in-person 6-11 months after hospitalization, with 377 patients assigned to a "no subjective memory complaint (SMC)" group and 231 patients assigned to an SMC group based on their Memory Complaint Scale scores. Follow-up evaluations included an objective cognitive battery and scale-based assessments of anxiety, depression, and post-traumatic stress symptoms. We found the perception of memory impairment in COVID-19 survivors to be more strongly associated to core symptoms of psychiatric conditions rather than to primary objective cognitive impairment. Univariate analysis indicated significant differences between the "no SMC" and SMC groups, both for the psychiatric symptom evaluations and for the cognitive evaluations (p < 0.05); however, the psychiatric symptoms all had large partial eta-squared values (ranging from 0.181 to 0.213), whereas the cognitive variables had small/medium partial eta-squared values (ranging from 0.002 to 0.024). Additionally, multiple regression analysis indicated that only female sex and depressive and post-traumatic stress symptoms were predictors of subjective memory complaints. These findings may help guide clinical evaluations for COVID-19 survivors presenting with memory complaints while also serving to expand our growing understanding of the relationship between COVID-19, subjective memory complaints, and the risk of cognitive decline.

Acute Administration of HIV-1 Tat Protein Drives Glutamatergic Alterations in a Rodent Model of HIV-Associated Neurocognitive Disorders

HIV-1-associated neurocognitive disorders (HAND) are a major comorbidity of HIV-1 infection, marked by impairment of executive function varying in severity. HAND affects nearly half of people living with HIV (PLWH), with mild forms predominating since the use of anti-retroviral therapies (ART). The HIV-1 transactivator of transcription (Tat) protein is found in the cerebrospinal fluid of patients adherent to ART, and its administration or expression in animals causes cognitive symptoms. Studies of Tat interaction with the N-methyl-D-aspartate receptor (NMDAR) suggest that glutamate toxicity contributes to Tat-induced impairments. To identify changes in regional glutamatergic circuitry underlying cognitive impairment, we injected recombinant Tat86 or saline to medial prefrontal cortex (mPFC) of male Sprague-Dawley rats. Rats were assessed with behavioral tasks that involve intact functioning of mPFC including the novel object recognition (NOR), spatial object recognition (SOR), and temporal order (TO) tasks at 1 and 2 postoperative weeks. Following testing, mPFC tissue was collected and analyzed by RT-PCR. Results showed Tat86 in mPFC-induced impairment in SOR, and upregulation of Grin1 and Grin2a transcripts. To further understand the mechanism of Tat toxicity, we assessed the effects of full-length Tat101 on gene expression in mPFC by RNA sequencing. The results of RNAseq suggest that glutamatergic effects of Tat86 are maintained with Tat101, as Grin2a was upregulated in Tat101-injected tissue, among other differentially expressed genes. Spatial learning and memory impairment and Grin2a upregulation suggest that exposure to Tat protein drives adaptation in mPFC, altering the function of circuitry supporting spatial learning and memory.

HLA-C*07 is associated with symptomatic HIV-1-associated neurocognitive disorders (HAND) and immune dysregulation

BACKGROUND

HIV-1-associated neurocognitive disorders (HAND) in stable patients undergoing antiretroviral therapy (ART) may result from ongoing immune dysregulation and chronic inflammation. A contributing factor may result from the unstable HLA class I allele, HLA-C*07.

OBJECTIVE

To assess the genetic profile of killer-cell immunoglobulin-like receptors (KIR), human leukocyte antigens (HLA), and immune activation or senescence markers and their association with HAND in stable HIV-1 patients receiving ART.

METHODS

An observational cross-sectional study was carried out with 96 patients with asymptomatic or symptomatic HAND. HLA and KIR as well as immune activation/senescence biomarkers in peripheral blood cells were assessed by SSO-Luminex typing and flow cytometry, respectively.

RESULTS

HLA-C*07 is associated with symptomatic HAND. The frequency of two copies of HLA-C*07 was higher in patients with symptomatic than with asymptomatic HAND (12.0 vs. 2.2%, ρ < 0.001). The percentage of senescent CD8+CD28- T-cells was higher in patients with two copies of HLA-C*07 (ρ < 0.05). In patients with symptomatic HAND, the percentages of non-senescent CD8+CD28+ T cells were inversely proportional to the number of copies of the HLA-C*07 (ρ < 0.05).

CONCLUSION

Patients with symptomatic HAND showed a higher frequency of the homozygotic unstable HLA-C*07 allotype, which could be associated with neurocognitive complications. Two copies of HLA-C*07 were associated with immune senescent T lymphocyte profiles characterized by the loss of CD28 expression.

HIV-associated neurocognitive disorder: key implications of the microbiota-gut-brain axis

HIV-associated neurocognitive disorder (HAND) is now recognized to be relatively common in people living with HIV (PLWH), and remains a common cause of cognitive impairment. Unfortunately, the fundamental pathogenic processes underlying this specific outcome of HIV infection have not as yet been fully elucidated. With increased interest in research related to the microbiota-gut-brain axis, the gut-brain axis has been shown to play critical roles in regulating central nervous system disorders such as Alzheimer's disease and Parkinson's disease. PLWH are characterized by a particular affliction, referred to as gut-associated dysbiosis syndrome, which provokes an alteration in microbial composition and diversity, and of their associated metabolite composition within the gut. Interestingly, the gut microbiota has also been recognized as a key element, which both positively and negatively influences human brain health, including the functioning and development of the central nervous system (CNS). In this review, based on published evidence, we critically discuss the relevant interactions between the microbiota-gut-brain axis and the pathogenesis of HAND in the context of HIV infection. It is likely that HAND manifestation in PLWH mainly results from (i) gut-associated dysbiosis syndrome and a leaky gut on the one hand and (ii) inflammation on the other hand. In other words, the preceding features of HIV infection negatively alter the composition of the gut microbiota (microbes and their associated metabolites) and promote proinflammatory immune responses which singularly or in tandem damage neurons and/or induce inadequate neuronal signaling. Thus, HAND is fairly prevalent in PLWH. This work aims to demonstrate that in the quest to prevent and possibly treat HAND, the gut microbiota may ultimately represent a therapeutically targetable "host factor."

Association between tight junction proteins and cognitive performance in untreated persons with HIV

BACKGROUND

HIV-associated neurocognitive disorders (HAND) still affects persons with HIV (PWH) and their pathogenesis is not completely understood. We aimed to explore the association between plasma and cerebrospinal fluid (CSF) markers of blood-brain barrier (BBB) impairment and HAND in untreated PWH.

DESIGN

Cross-sectional study.

METHODS

We enrolled untreated PWH, who underwent blood examinations and lumbar puncture to measure inflammation (IL-15, TNF-α), BBB damage (zonulin and tight junction proteins, tight junction proteins: occludin, claudin-5) and endothelial adhesion molecules (VCAM-1, ICAM-1). A comprehensive neurocognitive battery was used to diagnose HAND (Frascati criteria).

RESULTS

Twenty-one patients (21/78, 26.9%) patients presented HAND (100% ANI). HAND patients displayed more frequently non-CNS AIDS-defining conditions, lower nadir CD4 + T cells and increased CD4 + T-cell exhaustion (lower CD4 + CD127 + and CD4 + CD45RA + T-cell percentages), in comparison to individuals without cognitive impairment. Furthermore, HAND was characterized by higher plasma inflammation (IL-15) but lower CSF levels of biomarkers of BBB impairment (zonulin and occludin). The association between BBB damage with HAND was confirmed by fitting a multivariable logistic regression. CSF/plasma endothelial adhesion molecules were not associated with HAND but with a poor performance in different cognitive domains.

CONCLUSION

By showing heightened inflammation and BBB impairment, our study suggests loss of BBB integrity as a possible factor contributing to the development of HAND in untreated PWH.

Modulation of ER-mitochondria tethering complex VAPB-PTPIP51: Novel therapeutic targets for aging-associated diseases

Aging is a gradual and irreversible natural process. With aging, the body experiences a functional decline, and the effects amplify the vulnerability to a range of age-related diseases, including neurodegenerative, cardiovascular, and metabolic diseases. Within the aging process, the morphology and function of mitochondria and the endoplasmic reticulum (ER) undergo alterations, particularly in the structure connecting these organelles known as mitochondria-associated membranes (MAMs). MAMs serve as vital intracellular signaling hubs, facilitating communication between the ER and mitochondria when regulating various cellular events, including calcium homeostasis, lipid metabolism, mitochondrial function, and apoptosis. The formation of MAMs is partly dependent on the interaction between the vesicle-associated membrane protein-associated protein-B (VAPB) and protein tyrosine phosphatase-interacting protein-51 (PTPIP51). Accumulating evidence has begun to elucidate the pivotal role of the VAPB-PTPIP51 tether in the initiation and progression of age-related diseases. In this study, we delineate the intricate structure and multifunctional role of the VAPB-PTPIP51 tether and discuss its profound implications in aging-associated diseases. Moreover, we provide a comprehensive overview of potential therapeutic interventions and pharmacological agents targeting the VAPB-PTPIP51-mediated MAMs, thereby offering a glimmer of hope in mitigating aging processes and treating age-related disorders.

The Effects of Transcranial Direct Current Stimulation (tDCS) in HIV Patients-A Review

Introduction: HIV is a severe and incurable disease that has a devastating impact worldwide. It affects the immune system and negatively affects the nervous system, leading to various cognitive and behavioral problems. Scientists are actively exploring different therapeutic approaches to combat these issues. One promising method is transcranial direct current stimulation (tDCS), a non-invasive technique that stimulates the brain. Methods: This review aims to examine how tDCS can help HIV patients. Searches were conducted in the Pubmed/Medline, Research Gate, and Cochrane databases. Results: The literature search resulted in six articles focusing on the effects of tDCS on cognitive and behavioral measures in people with HIV. In some cases, tDCS showed positive improvements in the measures assessed, improving executive functions, depression, attention, reaction time, psychomotor speed, speed of processing, verbal learning and memory, and cognitive functioning. Furthermore, the stimulation was safe with no severe side effects. However, the included studies were of low quality, had small sample sizes, and did not use any relevant biomarkers that would help to understand the mechanisms of action of tDCS in HIV. Conclusions: tDCS may help patients with HIV; however, due to the limited number of studies and the diversity of protocols used, caution should be exercised when recommending this treatment option in clinical settings. More high-quality research, preferably involving neurophysiological and neuroimaging measurements, is necessary to better understand how tDCS works in individuals with HIV.

Sustained type I interferon signaling after human immunodeficiency virus type 1 infection of human iPSC derived microglia and cerebral organoids

Human immunodeficiency virus type-1 (HIV-1)-associated neurocognitive disorder (HAND) affects up to half of people living with HIV-1 and causes long term neurological consequences. The pathophysiology of HIV-1-induced glial and neuronal functional deficits in humans remains enigmatic. To bridge this gap, we established a model simulating HIV-1 infection in the central nervous system using human induced pluripotent stem cell (iPSC)-derived microglia combined with sliced neocortical organoids. Incubation of microglia with two replication-competent macrophage-tropic HIV-1 strains (JRFL and YU2) elicited productive infection and inflammatory activation. RNA sequencing revealed significant and sustained activation of type I interferon signaling pathways. Incorporating microglia into sliced neocortical organoids extended the effects of aberrant type I interferon signaling in a human neural context. Collectively, our results illuminate a role for persistent type I interferon signaling in HIV-1-infected microglia in a human neural model, suggesting its potential significance in the pathogenesis of HAND.

Autophagy Deregulation in HIV-1-Infected Cells Increases Extracellular Vesicle Release and Contributes to TLR3 Activation

Human immunodeficiency virus type 1 (HIV-1) infection can result in HIV-associated neurocognitive disorder (HAND), a spectrum of disorders characterized by neurological impairment and chronic inflammation. Combined antiretroviral therapy (cART) has elicited a marked reduction in the number of individuals diagnosed with HAND. However, there is continual, low-level viral transcription due to the lack of a transcription inhibitor in cART regimens, which results in the accumulation of viral products within infected cells. To alleviate stress, infected cells can release accumulated products, such as TAR RNA, in extracellular vesicles (EVs), which can contribute to pathogenesis in neighboring cells. Here, we demonstrate that cART can contribute to autophagy deregulation in infected cells and increased EV release. The impact of EVs released from HIV-1 infected myeloid cells was found to contribute to CNS pathogenesis, potentially through EV-mediated TLR3 (Toll-like receptor 3) activation, suggesting the need for therapeutics to target this mechanism. Three HIV-1 TAR-binding compounds, 103FA, 111FA, and Ral HCl, were identified that recognize TAR RNA and reduce TLR activation. These data indicate that packaging of viral products into EVs, potentially exacerbated by antiretroviral therapeutics, may induce chronic inflammation of the CNS observed in cART-treated patients, and novel therapeutic strategies may be exploited to mitigate morbidity.

Multimodal Approach to Neurocognitive Function in People Living with HIV in the cART Era: A Comprehensive Review

Combination antiretroviral treatment (cART) has revolutionized the management of human immunodeficiency virus (HIV) and has markedly improved the disease burden and life expectancy of people living with HIV. HIV enters the central nervous system (CNS) early in the course of infection, establishes latency, and produces a pro-inflammatory milieu that may affect cognitive functions, even in the cART era. Whereas severe forms of neurocognitive impairment (NCI) such as HIV-associated dementia have declined over the last decades, milder forms have become more prevalent, are commonly multifactorial, and are associated with comorbidity burdens, mental health, cART neurotoxicity, and ageing. Since 2007, the Frascati criteria have been used to characterize and classify HIV-associated neurocognitive disorders (HAND) into three stages, namely asymptomatic neurocognitive impairment (ANI), mild neurocognitive disorder (MND), and HIV-associated dementia (HAD). These criteria are based on a comprehensive neuropsychological assessment that presupposes the availability of validated, demographically adjusted, and normative population data. Novel neuroimaging modalities and biomarkers have been proposed in order to complement NCI assessments, elucidate neuropathogenic mechanisms, and support HIV-associated NCI diagnosis, monitoring, and prognosis. By integrating neuropsychological assessments with biomarkers and neuroimaging into a holistic care approach, clinicians can enhance diagnostic accuracy, prognosis, and patient outcomes. This review interrogates the value of these modes of assessment and proposes a unified approach to NCI diagnosis.

Molecular Role of HIV-1 Human Receptors (CCL5-CCR5 Axis) in neuroAIDS: A Systematic Review

Chronic HIV-1 infection can cause neurological illness, also known as HIV-associated neurocognitive disorders (HAND). The elevated level of pro-inflammatory cytokines and chemokines, such as C-C Chemokine Ligand 5 (CCL5/RANTES), is one of the ways of causing HIV-1-mediated neuroinflammation. C-C Chemokine Receptor 5 (CCR5) is the main coreceptor for viral entry into host cells and for mediating induction of CCL5/RANTES. CCR5 and CCL5 are part of a correlated axis of immune pathways used for effective protection against the HIV-1 virus. The purpose of this paper was to review the literary knowledge about the immunopathological relationship between this immune complex and neuroAIDS. A systematic review of the literature was conducted based on the selection and search of articles, available in English, Spanish, or Portuguese in the time frame of 1990-2022, of primary and secondary types in the PUBMED, Science Direct, SciELO, and LILACS databases through descriptors (MeSH) together with "AND": "CCR5"; "CCL5"; "neurological manifestations"; or "HIV". The methodological quality of the articles was assessed using the JBI Checklists and the PRISMA 2020 writing guidelines were followed. A total of 36 articles were included in the final composition of the review. The main cells of the CNS affected by neuroAIDS are: neurons; microglia; astrocytes; and oligodendrocytes. Molecular devices and their associations with cellular injuries have been described from the entry of the virus into the host's CNS cell to the generation of mental disorders. Furthermore, divergent results were found about the levels of CCL5/RANTES secretion and the generation of immunopathogenesis, while all condensed research for CCR5 indicated that elevation of this receptor causes more neurodegenerative manifestations. Therefore, new therapeutic and interventional strategies can be conditioned on the immunological direction proposed in this review for the disease.

Role of pyroptosis in the pathogenesis of various neurological diseases

Pyroptosis, an inflammatory programmed cell death process, has recently garnered significant attention due to its pivotal role in various neurological diseases. This review delves into the intricate molecular signaling pathways governing pyroptosis, encompassing both caspase-1 dependent and caspase-1 independent routes, while emphasizing the critical role played by the inflammasome machinery in initiating cell death. Notably, we explore the Nucleotide-binding domain leucine-rich repeat (NLR) containing protein family, the Absent in melanoma 2-like receptor family, and the Pyrin receptor family as essential activators of pyroptosis. Additionally, we comprehensively examine the Gasdermin family, renowned for their role as executioner proteins in pyroptosis. Central to our review is the interplay between pyroptosis and various central nervous system (CNS) cell types, including astrocytes, microglia, neurons, and the blood-brain barrier (BBB). Pyroptosis emerges as a significant factor in the pathophysiology of each cell type, highlighting its far-reaching impact on neurological diseases. This review also thoroughly addresses the involvement of pyroptosis in specific neurological conditions, such as HIV infection, drug abuse-mediated pathologies, Alzheimer's disease, and Parkinson's disease. These discussions illuminate the intricate connections between pyroptosis, chronic inflammation, and cell death in the development of these disorders. We also conducted a comparative analysis, contrasting pyroptosis with other cell death mechanisms, thereby shedding light on their unique aspects. This approach helps clarify the distinct contributions of pyroptosis to neuroinflammatory processes. In conclusion, this review offers a comprehensive exploration of the role of pyroptosis in various neurological diseases, emphasizing its multifaceted molecular mechanisms within various CNS cell types. By elucidating the link between pyroptosis and chronic inflammation in the context of neurodegenerative disorders and infections, it provides valuable insights into potential therapeutic targets for mitigating these conditions.

Lipid Droplets Accumulation in the Brain of HIV Transgenic Rat: Implication in the Accelerated Aging of HIV Infected Individuals

Abnormal microglial activation has been suggested as "driven force" promoting brain aging. Lipid droplets accumulating microglia (LDAM), identified as a novel inflammatory phenotype, elevate neuroinflammation and exaggerate neuronal injuries in aging and multiple neurodegenerative diseases. Since chronic HIV (human immunodeficiency virus) (+) individuals show an accelerated brain aging and higher incidence of neurological symptoms compared to age-matched HIV (-) population, we hypothesize that LDAM are also involved in such phenomenon. For validating the hypothesis, we employed HIV transgenic (HIV-Tg) and wilt type (WT) rats to check lipid droplets (LDs) accumulation in the brains at mature (6 months) and middle age (12 months). Our results showed that HIV-Tg rats possess higher levels of LDs formation in the hippocampus (HP) and prefrontal cortex (PFc) than controls at middle age. Increased LDs are mainly presented in microglia in the HP but largely co-localized with astrocytes in the PFc. Interestingly, increased LDs are associated with upregulation on Iba1 but not with GFAP levels. HIV-Tg rats reveal an accelerated LDs accumulation during normal aging. Purified microglia from HIV-Tg rats (12 month) show higher expression of neuroimmune signaling than microglia from controls. HIV-Tg rats showed dysregulation on cholesterol synthesis in the brain HP as well as deficiency on locomotion coordination compared to controls. Overall, our results demonstrate substantial LDs accumulation in the brains of HIV-Tg rats which is associated with abnormal microglial activation and accelerated decline on locomotion coordination during aging. Dysregulation on lipid metabolism might underlie accelerated brain aging in the context of chronic HIV infection.

Upstream lipid and metabolic systems are potential causes of Alzheimer's disease, Parkinson's disease and dementias

Brain health requires circuits, cells and molecular pathways to adapt when challenged and to promptly reset once the challenge has resolved. Neurodegeneration occurs when adaptability becomes confined, causing challenges to overwhelm neural circuitry. Studies of rare and common neurodegenerative diseases suggest that the accumulation of lipids can compromise circuit adaptability. Using microglia as an example, we review data that suggest increased lipid concentrations cause dysfunctional inflammatory responses to immune challenges, leading to Alzheimer's disease, Parkinson's disease and dementia. We highlight current approaches to treat lipid metabolic and clearance pathways and identify knowledge gaps towards restoring adaptive homeostasis in individuals who are at-risk of losing cognition.

Mitochondrial DNA mutation pathogenicity score and neurocognitive performance in persons with HIV

BACKGROUND

Mitochondrial DNA (mtDNA) genetic variation is associated with neurocognitive (NC) impairment (NCI) in people with HIV (PWH). Other approaches use sequence conservation and protein structure to predict the impact of mtDNA variants on protein function. We examined predicted mtDNA variant pathogenicity in the CHARTER study using MutPred scores, hypothesizing that persons with higher scores (greater predicted pathogenicity) have more NCI.

METHODS

CHARTER included NC testing in PWH from 2003 to 2007. MutPred scores were assigned to CHARTER participants with mtDNA sequence; any score > 0.5 was considered potentially deleterious. Outcomes at cohort entry were NCI, defined by global and seven NC domain deficit scores, and by mean global and domain NC performance T-scores. Univariate and multivariable regression analyses assessed associations between having a deleterious variant and NCI. Additional models included estimated peripheral blood cell mtDNA copy number.

RESULTS

Data were available for 744 PWH (357 African ancestry; 317 European; 70 Hispanic). In the overall cohort, PWH having any potentially deleterious variant were less likely to have motor impairment (16 vs. 25 %, p = 0.001). In multivariable analysis, having a deleterious variant remained associated with lower likelihood of motor impairment (adjusted odds ratio 0.59 [95 % CI 0.41-0.88]; p = 0.009), and better motor performance by T-score (β 1.71 [0.31-3.10], p = 0.02). Associations persisted after adjustment for estimated mtDNA quantity.

CONCLUSIONS

In these PWH, having a potentially deleterious mtDNA variant was associated with less motor impairment. These unexpected findings suggest that potentially deleterious mtDNA variations may confer protection against impaired motor function by as yet unknown mechanisms.

Neurological Complications Caused by Human Immunodeficiency Virus (HIV) and Associated Opportunistic Co-infections: A Review on their Diagnosis and Therapeutic Insights

Neurocognitive disorders associated with human immunodeficiency virus (HIV) infected individuals increase the risk of mortality and morbidity that remain a prevalent clinical complication even in the antiretroviral therapy era. It is estimated that a considerable number of people in the HIV community are developing neurological complications at their early stages of infection. The daily lives of people with chronic HIV infections are greatly affected by cognitive declines such as loss of attention, learning, and executive functions, and other adverse conditions like neuronal injury and dementia. It has been found that the entry of HIV into the brain and subsequently crossing the blood-brain barrier (BBB) causes brain cell damage, which is the prerequisite for the development of neurocognitive disorders. Besides the HIV replication in the central nervous system and the adverse effects of antiretroviral therapy on the BBB, a range of opportunistic infections, including viral, bacterial, and parasitic agents, augment the neurological complications in people living with HIV (PLHIV). Given the immuno-compromised state of PLHIV, these co-infections can present a wide range of clinical syndromes with atypical manifestations that pose challenges in diagnosis and clinical management, representing a substantial burden for the public health system. Therefore, the present review narrates the neurological complications triggered by HIV and their diagnosis and treatment options. Moreover, coinfections that are known to cause neurological disorders in HIV infected individuals are highlighted.

Frequent low-impact exposure to THC during adolescence causes persistent sexually dimorphic alterations in the response to viral infection in mice

Adolescent exposure to Δ9-tetrahydrocannabinol (THC) has enduring effects on energy metabolism and immune function. Prior work showed that daily administration of a low-impact dose of THC (5 mg/kg, intraperitoneal) during adolescence alters transcription in adult microglia and disrupts their response to bacterial endotoxin or social stress. To explore the lasting impact of adolescent THC exposure on the brain's reaction to viral infection, we administered THC (5 mg/kg, intraperitoneal) in male and female mice once daily on postnatal day (PND) 30-43. When the mice reached adulthood (PND 70), we challenged them with the viral mimic, polyinosinic acid:polycytidylic acid [Poly(I:C)], and assessed sickness behavior (motor activity, body temperature) and whole brain gene transcription. Poly(I:C) caused an elevation in body temperature which was lessened by prior THC exposure in female but not male mice. Adolescent THC exposure did not affect the locomotor response to Poly(I:C) in either sex. Transcriptomic analyses showed that Poly(I:C) produced a substantial upregulation of immune-related genes in the brain, which was decreased by THC in females. Additionally, the viral mimic caused a male-selective downregulation in transcription of genes involved in neurodevelopment and synaptic transmission, which was abrogated by adolescent THC treatment. The results indicate that Poly(I:C) produces complex transcriptional alterations in the mouse brain, which are sexually dimorphic and differentially affected by early-life THC exposure. In particular, adolescent THC dampens the brain's antiviral response to Poly(I:C) in female mice and prevents the transcriptional downregulation of neuron-related genes caused by the viral mimic in male mice.

HIV-1 infection of genetically engineered iPSC-derived central nervous system-engrafted microglia in a humanized mouse model

IMPORTANCE

Our mouse model is a powerful tool for investigating the genetic mechanisms governing central nervous system (CNS) human immunodeficiency virus type-1 (HIV-1) infection and latency in the CNS at a single-cell level. A major advantage of our model is that it uses induced pluripotent stem cell-derived microglia, which enables human genetics, including gene function and therapeutic gene manipulation, to be explored in vivo, which is more challenging to study with current hematopoietic stem cell-based models for neuroHIV. Our transgenic tracing of xenografted human cells will provide a quantitative medium to develop new molecular and epigenetic strategies for reducing the HIV-1 latent reservoir and to test the impact of therapeutic inflammation-targeting drug interventions on CNS HIV-1 latency.

Inhibition of lipid synthesis by the HIV integrase strand transfer inhibitor elvitegravir in primary rat oligodendrocyte cultures

Combined antiretroviral therapy (cART) has greatly decreased mortality and morbidity among persons with HIV; however, neurologic impairments remain prevalent, in particular HIV-associated neurocognitive disorders (HANDs). White matter damage persists in cART-treated persons with HIV and may contribute to neurocognitive dysfunction as the lipid-rich myelin membrane of oligodendrocytes is essential for efficient nerve conduction. Because of the importance of lipids to proper myelination, we examined the regulation of lipid synthesis in oligodendrocyte cultures exposed to the integrase strand transfer inhibitor elvitegravir (EVG), which is administered to persons with HIV as part of their initial regimen. We show that protein levels of genes involved in the fatty acid pathway were reduced, which correlated with greatly diminished de novo levels of fatty acid synthesis. In addition, major regulators of cellular lipid metabolism, the sterol regulatory element-binding proteins (SREBP) 1 and 2, were strikingly altered following exposure to EVG. Impaired oligodendrocyte differentiation manifested as a marked reduction in mature oligodendrocytes. Interestingly, most of these deleterious effects could be prevented by adding serum albumin, a clinically approved neuroprotectant. These new findings, together with our previous study, strengthen the possibility that antiretroviral therapy, at least partially through lipid dysregulation, may contribute to the persistence of white matter changes observed in persons with HIV and that some antiretrovirals may be preferable as life-long therapy.

An overview of neurocognitive impairment in older people living with HIV

Background

With improved survival among People Living with HIV (PLHIV), many are confronted with age associated comorbidities and geriatric syndromes. Neurocognitive impairment is one of the three most frequent conditions that affects quality of life of PLHIV despite achieving viral suppression. Healthcare providers face challenges in early identification of neurocognitive impairment, performing comprehensive assessment and managing older PLHIV.

Objectives

This paper aims to review available evidence regarding aetiology and management of older PLHIV who develop neurocognitive impairment, suggest improvements on current management and postulate future study direction.

Methods

A PubMed search for original articles and Clinical Guidelines was conducted from September 2021 to August 2022 using a combination of keywords related to neurocognitive impairment in PLHIV. The citations from all selected articles were reviewed for additional studies.

Results

Older PLHIV tend to be frailer than their uninfected counterparts, are plagued with multi-morbidity and are at increased risk of cognitive impairment. The aetiologies for neurocognitive impairment are multifactorial, multi-dimensional and complex. The management of neurocognitive impairment in older PLHIV involves identifying and optimizing predisposing factors, physical function, social and psychological health with appropriate care navigation.

Conclusion

Identification and management of neurocognitive impairment in older PLHIV through interdisciplinary collaboration among stakeholders is important. This exemplifies an integrated model of care for older PLHIV and promotes the notion of living well beyond viral suppression.

Genomic Exploration of the Brain in People Infected with HIV-Recent Progress and the Road Ahead

PURPOSE OF REVIEW

The adult human brain harbors billions of microglia and other myeloid and lymphoid cells highly susceptible to HIV infection and retroviral insertion into the nuclear DNA. HIV infection of the brain is important because the brain is a potentially large reservoir site that may be a barrier to HIV cure strategies and because infection can lead to the development of HIV-associated neurocognitive disorder. To better understand both the central nervous system (CNS) reservoir and how it can cause neurologic dysfunction, novel genomic, epigenomic, transcriptomic, and proteomic approaches need to be employed. Several characteristics of the reservoir are important to learn, including where the virus integrates, whether integrated proviruses are intact or defective, whether integrated proviruses can be reactivated from a latent state to seed ongoing infection, and how this all impacts brain function.

RECENT FINDINGS

Here, we discuss similarities and differences of viral integration sites between brain and blood and discuss evidence for and against the hypothesis that in the absence of susceptible T-lymphocytes in the periphery, the virus housing in the infected brain is not able to sustain a systemic infection. Moreover, microglia from HIV + brains across a wide range of disease severity appear to share one type of common alteration, which is defined by downregulated expression, and repressive chromosomal compartmentalization, for microglial genes regulating synaptic connectivity. Therefore, viral infection of the brain, including in immunocompetent cases with near-normal levels of CD4 blood lymphocytes, could be associated with an early disruption in microglia-dependent neuronal support functions, contributing to cognitive and neurological deficits in people living with HIV.

Neuro-HIV-New insights into pathogenesis and emerging therapeutic targets

HIV-associated neurocognitive disorders (HAND) is a term describing a complex set of cognitive impairments accompanying HIV infection. Successful antiretroviral therapy (ART) reduces the most severe forms of HAND, but milder forms affect over 50% of people living with HIV (PLWH). Pathogenesis of HAND in the ART era remains unknown. A variety of pathogenic factors, such as persistent HIV replication in the brain reservoir, HIV proteins released from infected brain cells, HIV-induced neuroinflammation, and some components of ART, have been implicated in driving HAND pathogenesis in ART-treated individuals. Here, we propose another factor-impairment of cholesterol homeostasis and lipid rafts by HIV-1 protein Nef-as a possible contributor to HAND pathogenesis. These effects of Nef on cholesterol may also underlie the effects of other pathogenic factors that constitute the multifactorial nature of HAND pathogenesis. The proposed Nef- and cholesterol-focused mechanism may provide a long-sought unified explanation of HAND pathogenesis that takes into account all contributing factors. Evidence for the impairment by Nef of cellular cholesterol balance, potential effects of this impairment on brain cells, and opportunities to therapeutically target this element of HAND pathogenesis are discussed.

Dysregulated neuroimmune interactions and sustained type I interferon signaling after human immunodeficiency virus type 1 infection of human iPSC derived microglia and cerebral organoids

Human immunodeficiency virus type-1 (HIV-1) associated neurocognitive disorder (HAND) affects up to half of HIV-1 positive patients with long term neurological consequences, including dementia. There are no effective therapeutics for HAND because the pathophysiology of HIV-1 induced glial and neuronal functional deficits in humans remains enigmatic. To bridge this knowledge gap, we established a model simulating HIV-1 infection in the central nervous system using human induced pluripotent stem cell (iPSC) derived microglia combined with sliced neocortical organoids. Upon incubation with two replication-competent macrophage-tropic HIV-1 strains (JRFL and YU2), we observed that microglia not only became productively infected but also exhibited inflammatory activation. RNA sequencing revealed a significant and sustained activation of type I interferon signaling pathways. Incorporating microglia into sliced neocortical organoids extended the effects of aberrant type I interferon signaling in a human neural context. Collectively, our results illuminate the role of persistent type I interferon signaling in HIV-1 infected microglial in a human neural model, suggesting its potential significance in the pathogenesis of HAND.

Current clinical presentations of AIDS dementia in a tropical environment: study of 26 observations in the neurology department of the University Hospital of Conakry

INTRODUCTION

In sub-Saharan Africa (SSA), the clinical and progressive diagnostic certainty of AIDS dementia is difficult to establish due to under-medicalization and delays in consultation and especially the diversity of etiologies of demented states.

MATERIAL AND METHODS

We carried out a retrospective study of 196 patients hospitalized for dementia syndrome between 2016 and 2021 in the neurology department of the University Hospital of Conakry. The criteria labeled in this study are those retained by the DSM-IV and the classification of the American Academy of Neurology (AAN) developed in accordance with the WHO.

RESULTS

HIV etiology was identified in patients aged 44-67 years (17 women and 19 men). The clinical picture was dominated by severe cognitive disorders, slowed ideation, memory disorders and reduced motor skills associated with personality changes. Neurological examination revealed dysphoric disorders in most patients, sphincter abnormalities in 13 cases and labio-lingual tremor in 11 cases. Diagnosis was based on positive serological tests for HIV1 antibodies (25 cases) and HIV2 antibodies (1 case) using the Elisa and Western blot techniques, and the presence of discretely hypercellular CSF. Magnetic resonance imaging contributed to the diagnosis, showing diffuse white matter abnormalities with hyper signals on T2-weighted or FLAIR sequences.

CONCLUSION

This study shows a non-stereotype clinical picture of AIDS dementia requiring a differential diagnosis with other infectious dementias. These results are important for the therapeutic and prognostic discussion.

Simian immunodeficiency virus-infected rhesus macaques with AIDS co-develop cardiovascular pathology and encephalitis

Despite effective antiretroviral therapy, HIV co-morbidities remain where central nervous system (CNS) neurocognitive disorders and cardiovascular disease (CVD)-pathology that are linked with myeloid activation are most prevalent. Comorbidities such as neurocogntive dysfunction and cardiovascular disease (CVD) remain prevalent among people living with HIV. We sought to investigate if cardiac pathology (inflammation, fibrosis, cardiomyocyte damage) and CNS pathology (encephalitis) develop together during simian immunodeficiency virus (SIV) infection and if their co-development is linked with monocyte/macrophage activation. We used a cohort of SIV-infected rhesus macaques with rapid AIDS and demonstrated that SIV encephalitis (SIVE) and CVD pathology occur together more frequently than SIVE or CVD pathology alone. Their co-development correlated more strongly with activated myeloid cells, increased numbers of CD14+CD16+ monocytes, plasma CD163 and interleukin-18 (IL-18) than did SIVE or CVD pathology alone, or no pathology. Animals with both SIVE and CVD pathology had greater numbers of cardiac macrophages and increased collagen and monocyte/macrophage accumulation, which were better correlates of CVD-pathology than SIV-RNA. Animals with SIVE alone had higher levels of activated macrophage biomarkers and cardiac macrophage accumulation than SIVnoE animals. These observations were confirmed in HIV infected individuals with HIV encephalitis (HIVE) that had greater numbers of cardiac macrophages and fibrosis than HIV-infected controls without HIVE. These results underscore the notion that CNS and CVD pathologies frequently occur together in HIV and SIV infection, and demonstrate an unmet need for adjunctive therapies targeting macrophages.

HIV and an Ageing Population-What Are the Medical, Psychosocial, and Palliative Care Challenges in Healthcare Provisions

The continuing increase in patient numbers and improvement in healthcare provisions of HIV services in the UK, alongside the effectiveness of combined antiretroviral therapy (cART), has resulted in increasing numbers of the ageing population among people living with HIV (PLWH). It is expected that geriatricians will need to deal with many older people living with HIV (OPLWH) as life expectancy increases. Therefore, geriatric syndromes in OPLWH will be similar to the normal population, such as falls, cognitive decline, frailty, dementia, hypertension, diabetes and polypharmacy. The increase in the long-term use of cART, diabetes, dyslipidaemia and hypertension may lead to high prevalence of cardiovascular disease (CVD). The treatment of such conditions may lead to polypharmacy and may increase the risk of cART drug-drug interactions. In addition, the risk of developing infection and cancer is high. OPLWH may develop an early onset of low bone mineral density (BMD), osteoporosis and fractures. In this review, we have also provided potential psychosocial aspects of an ageing population with HIV, addressing issues such as depression, stigma, isolation and the need for comprehensive medical and psychosocial care through an interdisciplinary team in a hospital or community setting. OPLWH have a relatively high burden of physical, psychological, and spiritual needs and social difficulties, which require palliative care. The holistic type of palliative care that will improve physical, emotional and psychological wellbeing is discussed in this review.

Application of infrared matrix-assisted laser desorption electrospray ionization mass spectrometry for morphine imaging in brain tissue

Here, we present a method developed for the analysis of spatial distributions of morphine in mouse brain tissue using infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) coupled to a Q Exactive Plus mass spectrometer. The method is also capable of evaluating spatial distributions of the antiretroviral drug abacavir. To maximize sensitivity to morphine, we analyze various Orbitrap mass spectrometry acquisition modes utilizing signal abundance and frequency of detection as evaluation criteria. We demonstrate detection of morphine in mouse brain and establish that the selected ion monitoring mode provides 2.5 times higher sensitivity than the full-scan mode. We find that distributions of morphine and abacavir are highly correlated with the Pearson correlation coefficient R = 0.87. Calibration showed that instrument response is linear up to 40 pg/mm2 (3.8 μg/g of tissue).

Role of Dysregulated Autophagy in HIV Tat, Cocaine, and cART Mediated NLRP3 Activation in Microglia

Despite the ability of combination antiretroviral therapy (cART) to suppress viremia, there is persistence low levels of HIV proteins such as Transactivator of transcription (Tat) in the central nervous system (CNS), contributing to glial activation and neuroinflammation. Accumulating evidence also implicates the role of drugs of abuse in exacerbating neurological complications associated with HIV-1. The combined effects of HIV Tat, drugs of abuse, and cART can thus create a toxic milieu in the CNS. The present study investigated the combinatorial effects of HIV-Tat, cocaine, and cART on autophagy and NLRP3 inflammasome activation. We selected a combination of three commonly used cART regimens: tenofovir, emtricitabine, and dolutegravir. Our results demonstrated that exposure of mouse primary microglia (MPMs) to these agents-HIV Tat (25 ng/ml), cocaine (1 μM), and cART (1 μM each) resulted in upregulation of autophagy markers: Beclin1, LC3B-II, and SQSTM1 with impaired lysosomal functioning involving increased lysosomal pH, decreased LAMP2 and cathepsin D, ultimately leading to dysregulated autophagy. Our findings also demonstrated activation of the NLRP3 signaling in microglia exposed to these agents. We further demonstrated that gene silencing of key autophagy protein BECN1 significantly blocked NLRP3-mediated activation of microglia. Silencing of NLRP3, however, failed to block HIV Tat, cocaine, and cART-mediated dysregulation of the autophagy-lysosomal axis; these in vitro phenomena were also validated in vivo using iTat mice administered cocaine and cART. This study thus underscores the cooperative effects of HIV Tat, cocaine, and cART in exacerbating microglial activation involving dysregulated autophagy and activation of the NLRP3 inflammasome signaling.

A new perspective on HIV: effects of HIV on brain-heart axis

The human immunodeficiency virus (HIV) infection can cause damage to multiple systems within the body, and the interaction among these various organ systems means that pathological changes in one system can have repercussions on the functions of other systems. However, the current focus of treatment and research on HIV predominantly centers around individual systems without considering the comprehensive relationship among them. The central nervous system (CNS) and cardiovascular system play crucial roles in supporting human life, and their functions are closely intertwined. In this review, we examine the effects of HIV on the CNS, the resulting impact on the cardiovascular system, and the direct damage caused by HIV to the cardiovascular system to provide new perspectives on HIV treatment.

Advances in HIV therapeutics and cure strategies: findings obtained through non-human primate studies

Human immunodeficiency virus (HIV), the main contributor of the ongoing AIDS epidemic, remains one of the most challenging and complex viruses to target and eradicate due to frequent genome mutation and immune evasion. Despite the development of potent antiretroviral therapies, HIV remains an incurable infection as the virus persists in latent reservoirs throughout the body. To innovate a safe and effective cure strategy for HIV in humans, animal models are needed to better understand viral proliferation, disease progression, and therapeutic response. Nonhuman primates infected with simian immunodeficiency virus (SIV) provide an ideal model to study HIV infection and pathogenesis as they are closely related to humans genetically and express phenotypically similar immune systems. Examining the clinical outcomes of novel treatment strategies within nonhuman primates facilitates our understanding of HIV latency and advances the development of a true cure to HIV.

Oncogenic Proteomics Approaches for Translational Research and HIV-Associated Malignancy Mechanisms

Recent advances in the field of proteomics have allowed extensive insights into the molecular regulations of the cell proteome. Specifically, this allows researchers to dissect a multitude of signaling arrays while targeting for the discovery of novel protein signatures. These approaches based on data mining are becoming increasingly powerful for identifying both potential disease mechanisms as well as indicators for disease progression and overall survival predictive and prognostic molecular markers for cancer. Furthermore, mass spectrometry (MS) integrations satisfy the ongoing demand for in-depth biomarker validation. For the purpose of this review, we will highlight the current developments based on MS sensitivity, to place quantitative proteomics into clinical settings and provide a perspective to integrate proteomics data for future applications in cancer precision medicine. We will also discuss malignancies associated with oncogenic viruses such as Acquire Immunodeficiency Syndrome (AIDS) and suggest novel mechanisms behind this phenomenon. Human Immunodeficiency Virus type-1 (HIV-1) proteins are known to be oncogenic per se, to induce oxidative and endoplasmic reticulum stresses, and to be released from the infected or expressing cells. HIV-1 proteins can act alone or in collaboration with other known oncoproteins, which cause the bulk of malignancies in people living with HIV-1 on ART.

HIV-1 envelope protein gp120 modulation of glutamate effects on cortical neuronal synapses: implications for HIV-1-associated neuropathogenesis

Despite the introduction of combined antiretroviral therapy (cART) HIV-1 virus persists in the brain in a latent or restricted manner and viral proteins, such as gp120, continue to play a significant disease-inciting role. Gp120 is known to interact with N-methyl-D-aspartate (NMDA) receptors (NMDARs) resulting in neuronal injury. Glutamate is the main excitatory neurotransmitter in the brain and plays an important role in cognitive function and dysregulation of excitatory synaptic transmission impairs neurocognition. It is our hypothesis that gp120 may alter synaptic function via modulating glutamate function from a physiological molecule to a pathophysiological substance. To test this hypothesis, we studied the modulatory effects of gp120 and glutamate on NMDAR-mediated spontaneous excitatory postsynaptic current (sEPSCNMDAR) and dynamic dendritic spine changes in rat cortical neuronal cultures. Our results revealed that gp120 and glutamate each, at low concentrations, had no significant effects on sEPSCNMDAR and dendritic spines, but increased sEPSCNMDAR frequency, decreased numbers of dendritic spines when tested in combination. The observed effects were blocked by either a CXCR4 blocker or an NMDAR antagonist, indicating the involvements of chemokine receptor CXCR4 and NMDARs in gp120 modulation of glutamate effects. These results may imply a potential mechanism for HIV-1-associated neuropathogenesis in the cART era.

Undiagnosed Cognitive Impairment and Impact on Instrumental Activities of Daily Living Among People With HIV Infection in Primary Care

Background

Little is known about the prevalence of undiagnosed cognitive impairment and its impact on instrumental activities of daily living (IADL) among people with HIV (PWH) in primary care.

Methods

PWH were recruited from an integrated health care setting in the United States. PWH were eligible for recruitment if they were ≥50 years old, taking antiretroviral therapy (ie, ≥1 antiretroviral therapy [ART] prescription fill in the past year), and had no clinical diagnosis of dementia. Participants completed a cognitive screen (St. Louis University Mental Status exam) and a questionnaire on IADL (modified Lawton-Brody).

Results

Study participants (n = 47) were mostly male (85.1%), 51.1% White, 25.5% Black, 17.0% Hispanic, and the average age (SD) was 59.7 (7.0) years. Overall, 27 (57.5%) participants were categorized as cognitively normal, 17 (36.2%) as having mild cognitive impairment, and 3 (6.4%) as having possible dementia. Of the 20 participants with mild cognitive impairment or possible dementia, 85.0% were men, the average age (SD) was 60.4 (7.1) years; 45.0% were White, 40.0% were Black, 10.0% were Hispanic, and 30.0% reported difficulty with at least 1 IADL. Most (66.7%) attributed difficulty with IADL primarily (33.3%) or in part (33.3%) to cognitive problems.

Conclusions

Undiagnosed cognitive impairment is frequent among ART-treated PWH, with possible elevated risk among Black PWH, and may be accompanied by difficulty with IADL. Efforts are needed to optimize identification of factors contributing to cognitive and IADL difficulties among ART-treated PWH in primary care.

Biosafety and mental health: Virus induced cognitive decline

Biological agents threats people's life through different ways, one of which lies in the impairment of cognition. It is believed cognitive decline may result from biological agents mediated neuron damage directly, or from the activation of the host immune response to eradicate the pathogen. However, direct linkage between infections and cognitive decline is very limited. Here we focus on the mechanisms of how different biological virus or they induced systemic and local inflammation link to the cognitive impairment, focusing on the roles of activated microglia and several molecular pathways mediated neurotoxicity.

The Impact of COVID-19 on People Living with HIV-1 and HIV-1-Associated Neurological Complications

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the causative pathogen of the coronavirus disease 2019 (COVID-19) pandemic, a fatal respiratory illness. The associated risk factors for COVID-19 are old age and medical comorbidities. In the current combined antiretroviral therapy (cART) era, a significant portion of people living with HIV-1 (PLWH) with controlled viremia is older and with comorbidities, making these people vulnerable to SARS-CoV-2 infection and COVID-19-associated severe outcomes. Additionally, SARS-CoV-2 is neurotropic and causes neurological complications, resulting in a health burden and an adverse impact on PLWH and exacerbating HIV-1-associated neurocognitive disorder (HAND). The impact of SARS-CoV-2 infection and COVID-19 severity on neuroinflammation, the development of HAND and preexisting HAND is poorly explored. In the present review, we compiled the current knowledge of differences and similarities between SARS-CoV-2 and HIV-1, the conditions of the SARS-CoV-2/COVID-19 and HIV-1/AIDS syndemic and their impact on the central nervous system (CNS). Risk factors of COVID-19 on PLWH and neurological manifestations, inflammatory mechanisms leading to the neurological syndrome, the development of HAND, and its influence on preexisting HAND are also discussed. Finally, we have reviewed the challenges of the present syndemic on the world population, with a particular emphasis on PLWH.

HIV-1 infection of genetically engineered iPSC-derived central nervous system-engrafted microglia in a humanized mouse model

The central nervous system (CNS) is a major human immunodeficiency virus type 1 reservoir. Microglia are the primary target cell of HIV-1 infection in the CNS. Current models have not allowed the precise molecular pathways of acute and chronic CNS microglial infection to be tested with in vivo genetic methods. Here, we describe a novel humanized mouse model utilizing human-induced pluripotent stem cell-derived microglia to xenograft into murine hosts. These mice are additionally engrafted with human peripheral blood mononuclear cells that served as a medium to establish a peripheral infection that then spread to the CNS microglia xenograft, modeling a trans-blood-brain barrier route of acute CNS HIV-1 infection with human target cells. The approach is compatible with iPSC genetic engineering, including inserting targeted transgenic reporter cassettes to track the xenografted human cells, enabling the testing of novel treatment and viral tracking strategies in a comparatively simple and cost-effective way vivo model for neuroHIV.