Publications by authors named "Benjamin Gelman"

121 Publications

Paresthesia Predicts Increased Risk of Distal Neuropathic Pain in Older People with HIV-Associated Sensory Polyneuropathy.

Pain Med 2021 Feb 10. Epub 2021 Feb 10.

Department of Neurosciences, University of California, San Diego.

Objective: Distal sensory polyneuropathy (DSP) is a disabling consequence of HIV, leading to poor quality of life and more frequent falls in older age. Neuropathic pain and paresthesia are prevalent symptoms, however there are currently no known curative treatments and the longitudinal course of pain in HIV-associated DSP is poorly characterized.

Methods: This was a prospective longitudinal study of 265 PWH enrolled in the CNS HIV Antiretroviral Therapy Effects Research (CHARTER) study with baseline and 12-year follow-up evaluations. Since pain and paresthesia are highly correlated, statistical decomposition was used to separate the two symptoms at baseline. Multivariable logistic regression analyses of decomposed variables were used to determine the effects of neuropathy symptoms at baseline on presence and worsening of distal neuropathic pain at 12-year follow-up, adjusted for covariates.

Results: Mean age was 56 ± 8 years, and 21% were female at follow-up. Nearly the entire cohort (96%) was on antiretroviral therapy (ART) and 82% had suppressed (≤50 copies/mL) plasma viral loads at follow-up. Of those with pain at follow-up (n = 100), 23% had paresthesia at the initial visit. Decomposed paresthesia at baseline increased the risk of pain at follow-up (OR 1.56; 95% CI 1.18, 2.07), and decomposed pain at baseline predicted a higher frequency of pain at follow-up (OR 1.96 [1.51, 2.58]).

Conclusions: Paresthesias are a clinically significant predictor of incident pain at follow-up among aging PWH with DSP. Development of new therapies to encourage neuroregeneration might take advantage of this finding to choose individuals likely to benefit from treatment preventing incident pain.
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http://dx.doi.org/10.1093/pm/pnab056DOI Listing
February 2021

Acrolein and other toxicant exposures in relation to cardiovascular disease among marijuana and tobacco smokers in a longitudinal cohort of HIV-positive and negative adults.

EClinicalMedicine 2021 Jan 11;31:100697. Epub 2021 Jan 11.

Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Center for Life Science 1010, 450 Brookline Avenue, Boston, MA 02215, USA.

Background: Marijuana smoke contains some of the same toxicants present in tobacco smoke. Marijuana smoking is prevalent among HIV+ individuals, but few studies have characterized smoke-related toxicants or associated health outcomes in exclusive marijuana users.

Methods: This longitudinal study included 245 participants over age 40 (76% HIV+). 33 plasma and 28 urine metabolites of nicotine, ∆-9-trans-tetrahydrocannabinol, polycyclic aromatic hydrocarbons, and volatile organic compounds were assayed by liquid or gas chromatography/mass spectrometry. Exposures and health outcomes were assessed from surveys and medical records.

Findings: At baseline, 18% of participants were marijuana-only smokers, 20% tobacco-only smokers, and 24% dual marijuana-tobacco smokers (median (IQR) age 53 (47-60) years, 78% male, 54% white race). Marijuana smoking was independently associated with elevated plasma naphthalenes, 2-hydroxyfluorene sulfate, 4-vinylphenol sulfate, and o-cresol sulfate 0·05) and urine acrylonitrile and acrylamide metabolites (0·05), but levels were lower than those associated with tobacco smoking. Acrolein metabolite N-Acetyl-S-(3-hydroxypropyl)-l-cysteine (3HPMA) was significantly elevated in plasma and urine in tobacco-only and dual but not marijuana-only smokers, and correlated with nicotine metabolites (0·05). The highest tertile of 3HPMA was associated with increased cardiovascular disease diagnoses independent of tobacco smoking, traditional risk factors, and HIV status (odds ratio [95% CI] 3·34 [1·31-8·57];   0·012).

Interpretation: Smoke-related toxicants, including acrylonitrile and acrylamide metabolites, are detectable in exclusive marijuana smokers, but exposures are lower compared with tobacco or dual smokers. Acrolein exposure is increased by tobacco smoking but not exclusive marijuana smoking in HIV+ and HIV- adults, and contributes to cardiovascular disease in tobacco smokers.

Funding: U.S. NIH.
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http://dx.doi.org/10.1016/j.eclinm.2020.100697DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7846668PMC
January 2021

Neuroinflammation associates with antioxidant heme oxygenase-1 response throughout the brain in persons living with HIV.

J Neurovirol 2020 12 10;26(6):846-862. Epub 2020 Sep 10.

Department of Neurology, Perelman School of Medicine, University of Pennsylvania, 280 Clinical Research Building, 415 Curie Blvd., Philadelphia, PA, 19104, USA.

Previous studies showed that persons living with HIV (PLWH) demonstrate higher brain prefrontal cortex neuroinflammation and immunoproteasome expression compared to HIV-negative individuals; these associate positively with HIV levels. Lower expression of the antioxidant enzyme heme oxygenase 1 (HO-1) was observed in PLWH with HIV-associated neurocognitive impairment (HIV-NCI) compared to neurocognitively normal PLWH. We hypothesized that similar expression patterns occur throughout cortical, subcortical, and brainstem regions in PLWH, and that neuroinflammation and immunoproteasome expression associate with lower expression of neuronal markers. We analyzed autopsied brains (15 regions) from 9 PLWH without HIV-NCI and 7 matched HIV-negative individuals. Using Western blot and RT-qPCR, we quantified synaptic, inflammatory, immunoproteasome, endothelial, and antioxidant biomarkers, including HO-1 and its isoform heme oxygenase 2 (HO-2). In these PLWH without HIV-NCI, we observed higher expression of neuroinflammatory, endothelial, and immunoproteasome markers in multiple cortical and subcortical regions compared to HIV-negative individuals, suggesting a global brain inflammatory response to HIV. Several regions, including posterior cingulate cortex, globus pallidus, and cerebellum, showed a distinct pattern of higher type I interferon (IFN)-stimulated gene and immunoproteasome expression. PLWH without HIV-NCI also had (i) stable or higher HO-1 expression and positive associations between (ii) HO-1 and HIV levels (CSF, plasma) and (iii) HO-1 expression and neuroinflammation, in multiple cortical, subcortical, and brainstem regions. We observed no differences in synaptic marker expression, suggesting little, if any, associated neuronal injury. We speculate that this may reflect a neuroprotective effect of a concurrent HO-1 antioxidant response despite global neuroinflammation, which will require further investigation.
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http://dx.doi.org/10.1007/s13365-020-00902-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7716923PMC
December 2020

Lipocalin-2 mediates HIV-1 induced neuronal injury and behavioral deficits by overriding CCR5-dependent protection.

Brain Behav Immun 2020 10 11;89:184-199. Epub 2020 Jun 11.

Division of Biomedical Sciences, School of Medicine, University of California, Riverside, 900 University Ave, Riverside, CA 92521, USA; Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA. Electronic address:

People living with HIV (PLWH) continue to develop HIV-associated neurocognitive disorders despite combination anti-retroviral therapy. Lipocalin-2 (LCN2) is an acute phase protein that has been implicated in neurodegeneration and is upregulated in a transgenic mouse model of HIV-associated brain injury. Here we show that LCN2 is significantly upregulated in neocortex of a subset of HIV-infected individuals with brain pathology and correlates with viral load in CSF and pro-viral DNA in neocortex. However, the question if LCN2 contributes to HIV-associated neurotoxicity or is part of a protective host response required further investigation. We found that the knockout of LCN2 in transgenic mice expressing HIVgp120 in the brain (HIVgp120tg) abrogates behavioral impairment, ameliorates neuronal damage, and reduces microglial activation in association with an increase of the neuroprotective CCR5 ligand CCL4. In vitro experiments show that LCN2 neurotoxicity also depends on microglia and p38 MAPK activity. Genetic ablation of CCR5 in LCN2-deficient HIVgp120tg mice restores neuropathology, suggesting that LCN2 overrides neuroprotection mediated by CCR5 and its chemokine ligands. RNA expression of 168 genes involved in neurotransmission reveals that neuronal injury and protection are each associated with genotype- and sex-specific patterns affecting common neural gene networks. In conclusion, our study identifies LCN2 as a novel factor in HIV-associated brain injury involving CCR5, p38 MAPK and microglia. Furthermore, the mechanistic interaction between LCN2 and CCR5 may serve as a diagnostic and therapeutic target in HIV patients at risk of developing brain pathology and neurocognitive impairment.
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http://dx.doi.org/10.1016/j.bbi.2020.06.016DOI Listing
October 2020

Small Animal Model of Post-chemotherapy Tuberculosis Relapse in the Setting of HIV Co-infection.

Front Cell Infect Microbiol 2020 16;10:150. Epub 2020 Apr 16.

Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States.

Tuberculosis relapse following drug treatment of active disease is an important global public health problem due to the poorer clinical outcomes and increased risk of drug resistance development. Concurrent infection with HIV, including in those receiving anti-retroviral therapy (ART), is an important risk factor for relapse and expansion of drug resistant () isolates. A greater understanding of the HIV-associated factors driving TB relapse is important for development of interventions that support immune containment and complement drug therapy. We employed the humanized mouse to develop a new model of post-chemotherapy TB relapse in the setting of HIV infection. Paucibacillary TB infection was observed following treatment with Rifampin and Isoniazid and subsequent infection with HIV-1 was associated with increased burden in the post-drug phase. Organized granulomas were observed during development of acute TB and appeared to resolve following TB drug therapy. At relapse, granulomatous pathology in the lung was infrequent and mycobacteria were most often observed in the interstitium and at sites of diffuse inflammation. Compared to animals with HIV mono-infection, higher viral replication was observed in the lung and liver, but not in the periphery, of animals with post-drug TB relapse. The results demonstrate a potential role for the humanized mouse as an experimental model of TB relapse in the setting of HIV. Long term, the model could facilitate discovery of disease mechanisms and development of clinical interventions.
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http://dx.doi.org/10.3389/fcimb.2020.00150DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7176873PMC
April 2020

Heme oxygenase-1 promoter (GT) polymorphism associates with HIV neurocognitive impairment.

Neurol Neuroimmunol Neuroinflamm 2020 05 10;7(3). Epub 2020 Apr 10.

From the Department of Neurology (R. Garza, A.J.G., B.L.B., Y.G.-M., A.L.G., D.L.K.), Perelman School of Medicine, University of Pennsylvania, Philadelphia; Department of Pathology (B.B.G.), University of Texas Medical Branch, Galveston; Department of Family Medicine & Public Health (B.T.), University of Botswana, Gaborone; Departments of Medicine and Biostatistics (R. Gross), Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia; and Department of Medicine (S.L.L.), University of California, San Diego.

Objective: To determine whether regulatory variations in the heme oxygenase-1 (HO-1) promoter (GT) dinucleotide repeat length could identify unique population genetic risks for neurocognitive impairment (NCI) in persons living with HIV (PLWH), we genotyped 528 neurocognitively assessed PLWH of European American and African American descent and linked genotypes to cognitive status.

Methods: In this cross-sectional study of PLWH (the CNS HIV Antiretroviral Therapy Effect Research cohort), we determined HO-1 (GT) repeat lengths in 276 African Americans and 252 European Americans. Using validated criteria for HIV-associated NCI (HIV NCI), we found associations between allele length genotypes and HIV NCI and between genotypes and plasma markers of monocyte activation and inflammation. For comparison of HO-1 (GT) allele frequencies with another population of African ancestry, we determined HO-1 (GT) allele lengths in African PLWH from Botswana (n = 428).

Results: PLWH with short HO-1 (GT) alleles had a lower risk for HIV NCI (OR = 0.63, 95% CI: 0.42-0.94). People of African ancestry had a lower prevalence of short alleles and higher prevalence of long alleles compared with European Americans, and in subgroup analyses, the protective effect of the short allele was observed in African Americans and not in European Americans.

Conclusions: Our study identified the short HO-1 (GT) allele as partially protective against developing HIV NCI. It further suggests that this clinical protective effect is particularly relevant in persons of African ancestry, where the lower prevalence of short HO-1 (GT) alleles may limit induction of HO-1 expression in response to inflammation and oxidative stress. Therapeutic strategies that enhance HO-1 expression may decrease HIV-associated neuroinflammation and limit HIV NCI.
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http://dx.doi.org/10.1212/NXI.0000000000000710DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7176253PMC
May 2020

Epigenetic Suppression of HIV in Myeloid Cells by the BRD4-Selective Small Molecule Modulator ZL0580.

J Virol 2020 05 18;94(11). Epub 2020 May 18.

Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA

Brain-resident microglia and myeloid cells (perivascular macrophages) are important HIV reservoirs , especially in the central nervous system (CNS). Despite antiretroviral therapy (ART), low-level persistent HIV replication in these reservoirs remains detectable, which contributes to neuroinflammation and neurological disorders in HIV-infected patients. New approaches complementary to ART to repress residual HIV replication in CNS reservoirs are needed. Our group has recently identified a BRD4-selective small molecule modulator (ZL0580) that induces the epigenetic suppression of HIV. Here, we examined the effects of this compound on HIV in human myeloid cells. We found that ZL0580 induces potent and durable suppression of both induced and basal HIV transcription in microglial cells (HC69) and monocytic cell lines (U1 and OM10.1). Pretreatment of microglia with ZL0580 renders them more refractory to latent HIV reactivation, indicating an epigenetic reprogramming effect of ZL0580 on HIV long terminal repeat (LTR) in microglia. We also demonstrate that ZL0580 induces repressive effect on HIV in human primary monocyte-derived macrophages (MDMs) by promoting HIV suppression during ART treatment. Mechanistically, ZL0580 inhibits Tat transactivation in microglia by disrupting binding of Tat to CDK9, a process key to HIV transcription elongation. High-resolution micrococcal nuclease mapping showed that ZL0580 induces a repressive chromatin structure at the HIV LTR. Taken together, our data suggest that ZL0580 represents a potential approach that could be used in combination with ART to suppress residual HIV replication and/or latent HIV reactivation in CNS reservoirs, thereby reducing HIV-associated neuroinflammation. Brain-resident microglia and perivascular macrophages are important HIV reservoirs in the CNS. Persistent viral replication and latent HIV reactivation in the CNS, even under ART, are believed to occur, causing neuroinflammation and neurological disorders in HIV-infected patients. It is critical to identify new approaches that can control residual HIV replication and/or latent HIV reactivation in these reservoirs. We here report that the BRD4-selective small molecule modulator, ZL0580, induces potent and durable suppression of HIV in human microglial and monocytic cell lines. Using an HIV-infected, ART-treated MDM model, we show that ZL0580 also induces suppressive effect on HIV in human primary macrophages. The significance of our research is that it suggests a potential new approach that has utility in combination with ART to suppress residual HIV replication and/or HIV reactivation in CNS reservoirs, thereby reducing neuroinflammation and neurological disorders in HIV-infected individuals.
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http://dx.doi.org/10.1128/JVI.01880-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7269428PMC
May 2020

White Matter Abnormalities Linked to Interferon, Stress Response, and Energy Metabolism Gene Expression Changes in Older HIV-Positive Patients on Antiretroviral Therapy.

Mol Neurobiol 2020 Feb 5;57(2):1115-1130. Epub 2019 Nov 5.

Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, CLS 1010, 450 Brookline Ave, Boston, MA, 02215, USA.

Neurocognitive impairment (NCI) remains a significant cause of morbidity in human immunodeficiency virus (HIV)-positive individuals despite highly active antiretroviral therapy (HAART). White matter abnormalities have emerged as a key component of age-related neurodegeneration, and accumulating evidence suggests they play a role in HIV-associated neurocognitive disorders. Viral persistence in the brain induces chronic inflammation associated with lymphocytic infiltration, microglial proliferation, myelin loss, and cerebrovascular lesions. In this study, gene expression profiling was performed on frontal white matter from 34 older HIV+ individuals on HAART (18 with NCI) and 24 HIV-negative controls. We used the NanoString nCounter platform to evaluate 933 probes targeting inflammation, interferon and stress responses, energy metabolism, and central nervous system-related genes. Viral loads were measured using single-copy assays. Compared to HIV- controls, HIV+ individuals exhibited increased expression of genes related to interferon, MHC-1, and stress responses, myeloid cells, and T cells and decreased expression of genes associated with oligodendrocytes and energy metabolism in white matter. These findings correlated with increased white matter inflammation and myelin pallor, suggesting interferon (IRFs, IFITM1, ISG15, MX1, OAS3) and stress response (ATF4, XBP1, CHOP, CASP1, WARS) gene expression changes are associated with decreased energy metabolism (SREBF1, SREBF2, PARK2, TXNIP) and oligodendrocyte myelin production (MAG, MOG), leading to white matter dysfunction. Machine learning identified a 15-gene signature predictive of HIV status that was validated in an independent cohort. No specific gene expression patterns were associated with NCI. These findings suggest therapies that decrease chronic inflammation while protecting mitochondrial function may help to preserve white matter integrity in older HIV+ individuals.
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http://dx.doi.org/10.1007/s12035-019-01795-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7035207PMC
February 2020

Characteristics of Motor Dysfunction in Longstanding Human Immunodeficiency Virus.

Clin Infect Dis 2020 Sep;71(6):1532-1538

Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.

Background: Cognitive dysfunction in human immunodeficiency virus (HIV) has decreased, but milder forms of HIV-associated neurocognitive disorders (HAND) persist along with motor dysfunction. The HIV Motor Scale (HMS) is a validated tool that captures motor abnormalities on routine neurologic examination and which is associated with cognitive impairment in HIV. In this study, we applied a modified HMS (MHMS) to a nationwide cohort of people with longstanding HIV to characterize and understand the factors contributing to motor dysfunction.

Methods: The National NeuroAIDS Tissue Consortium is a nationwide longitudinal cohort study. Participants undergo regular assessments including neurological examination, neuropsychological testing, and immunovirologic data collection. Data from examinations were used to calculate the MHMS score, which was then correlated with history of AIDS-related central nervous system (CNS) disorders (ARCD; eg, prior CNS opportunistic infection), cerebrovascular disease (CVD), and HAND.

Results: Sixty-nine percent of participants showed an abnormality on the MHMS, with 27% classified as severe. Results did not vary based on demographic or immunologic variables. The most common abnormalities seen were gait (54%), followed by coordination (39%) and strength (25%), and these commonly co-occurred. CVD (P = .02), history of ARCD (P = .001), and HAND (P = .001) were all associated with higher (ie, worse) HMS in univariate analyses; CVD and ARCD persisted in multivariate analyses. CVD was also marginally associated with symptomatic HAND.

Conclusions: Complex motor dysfunction remains common in HIV and is associated with CVD, ARCD, and to a lesser extent, HAND. Future studies are needed to understand the longitudinal trajectory of HIV-associated motor dysfunction, its neural substrates, and impact on quality of life.
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http://dx.doi.org/10.1093/cid/ciz986DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7486845PMC
September 2020

Use of Neuroimaging to Inform Optimal Neurocognitive Criteria for Detecting HIV-Associated Brain Abnormalities.

J Int Neuropsychol Soc 2020 02 2;26(2):147-162. Epub 2019 Oct 2.

Department of Psychiatry, University of California, San Diego, La Jolla, CA 92093, USA.

Objective: Frascati international research criteria for HIV-associated neurocognitive disorders (HAND) are controversial; some investigators have argued that Frascati criteria are too liberal, resulting in a high false positive rate. Meyer et al. recommended more conservative revisions to HAND criteria, including exploring other commonly used methodologies for neurocognitive impairment (NCI) in HIV including the global deficit score (GDS). This study compares NCI classifications by Frascati, Meyer, and GDS methods, in relation to neuroimaging markers of brain integrity in HIV.

Method: Two hundred forty-one people living with HIV (PLWH) without current substance use disorder or severe (confounding) comorbid conditions underwent comprehensive neurocognitive testing and brain structural magnetic resonance imaging and magnetic resonance spectroscopy. Participants were classified using Frascati criteria versus Meyer criteria: concordant unimpaired [Frascati(Un)/Meyer(Un)], concordant impaired [Frascati(Imp)/Meyer(Imp)], or discordant [Frascati(Imp)/Meyer(Un)] which were impaired via Frascati criteria but unimpaired via Meyer criteria. To investigate the GDS versus Meyer criteria, the same groupings were utilized using GDS criteria instead of Frascati criteria.

Results: When examining Frascati versus Meyer criteria, discordant Frascati(Imp)/Meyer(Un) individuals had less cortical gray matter, greater sulcal cerebrospinal fluid volume, and greater evidence of neuroinflammation (i.e., choline) than concordant Frascati(Un)/Meyer(Un) individuals. GDS versus Meyer comparisons indicated that discordant GDS(Imp)/Meyer(Un) individuals had less cortical gray matter and lower levels of energy metabolism (i.e., creatine) than concordant GDS(Un)/Meyer(Un) individuals. In both sets of analyses, the discordant group did not differ from the concordant impaired group on any neuroimaging measure.

Conclusions: The Meyer criteria failed to capture a substantial portion of PLWH with brain abnormalities. These findings support continued use of Frascati or GDS criteria to detect HIV-associated CNS dysfunction.
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http://dx.doi.org/10.1017/S1355617719000985DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7015796PMC
February 2020

Structure-guided drug design identifies a BRD4-selective small molecule that suppresses HIV.

J Clin Invest 2019 07 22;129(8):3361-3373. Epub 2019 Jul 22.

Department of Microbiology and Immunology, University of Texas Medical Branch (UTMB), Galveston, Texas, USA.

HIV integrates its provirus into the host genome and establishes latent infection. Antiretroviral therapy (ART) can control HIV viremia, but cannot eradicate or cure the virus. Approaches targeting host epigenetic machinery to repress HIV, leading to an aviremic state free of ART, are needed. Bromodomain and extraterminal (BET) family protein BRD4 is an epigenetic reader involved in HIV transcriptional regulation. Using structure-guided drug design, we identified a small molecule (ZL0580) that induced epigenetic suppression of HIV via BRD4. We showed that ZL0580 induced HIV suppression in multiple in vitro and ex vivo cell models. Combination treatment of cells of aviremic HIV-infected individuals with ART and ZL0580 revealed that ZL0580 accelerated HIV suppression during ART and delayed viral rebound after ART cessation. Mechanistically different from the BET/BRD4 pan-inhibitor JQ1, which nonselectively binds to BD1 and BD2 domains of all BET proteins, ZL0580 selectively bound to BD1 domain of BRD4. We further demonstrate that ZL0580 induced HIV suppression by inhibiting Tat transactivation and transcription elongation as well as by inducing repressive chromatin structure at the HIV promoter. Our findings establish a proof of concept for modulation of BRD4 to epigenetically suppress HIV and provide a promising chemical scaffold for the development of probes and/or therapeutic agents for HIV epigenetic silencing.
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http://dx.doi.org/10.1172/JCI120633DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6668673PMC
July 2019

Frailty in medically complex individuals with chronic HIV.

AIDS 2019 08;33(10):1603-1611

Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, California, USA.

Objectives: Multimorbidity and frailty are consequences of aging with HIV, yet not everyone with medical disease is frail. Our objective was to identify factors associated with frailty in a multimorbid HIV-infected cohort.

Design: Analysis of a prospective, observational, longitudinal cohort.

Methods: Three hundred and thirty-two participants in the medically advanced National NeuroAIDS Tissue Consortium (NNTC) study were categorized as frail, prefrail, or robust with the Fried Frailty Index. A series of logistic regression analyses (first univariate, then multivariable) were conducted to determine whether medical comorbidities, immunologic and virologic parameters, and/or neuropsychiatric variables predicted increased odds of frailty.

Results: The mean number of medical comorbidities per participant was 2.7, mean CD4 T-cell count was 530 cells/μl, and 77% had undetectable HIV RNA in blood. Twenty-two percent were frail, 55% prefrail, and 23% robust. Significant predictors of frailty in multivariable analysis were cognitive diagnosis rendered by Frascati criteria, depressive symptoms, diabetes mellitus, chronic obstructive pulmonary disease (COPD), and sex. Men were less likely to be frail than women. Higher odds of frailty were seen with: symptomatic, but not asymptomatic, cognitive impairment (compared with cognitive normals); more depressive symptoms; diabetes mellitus; and COPD.

Conclusion: Neuropsychiatric illness increased odds of being frail on a predominantly physical/motoric measure, but only when symptomatic. Lack of association with asymptomatic impairment may reflect the importance of functional limitation to frailty, or possibly a unique resilience phenotype. Understanding why sex and symptomatic neuropsychiatric illness are associated with frailty will be important in managing HIV-associated morbidity in aging populations.
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http://dx.doi.org/10.1097/QAD.0000000000002250DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6760300PMC
August 2019

Correlates of HIV RNA concentrations in cerebrospinal fluid during antiretroviral therapy: a longitudinal cohort study.

Lancet HIV 2019 07 14;6(7):e456-e462. Epub 2019 Jun 14.

Department of Psychiatry, University of California San Diego, San Diego, CA, USA; Department of Medicine, University of California San Diego, San Diego, CA, USA. Electronic address:

Background: Few large projects have evaluated the factors that influence the HIV RNA concentrations (viral load) in cerebrospinal fluid (CSF) during antiretroviral therapy (ART) over time. We aimed to determine the correlates of HIV RNA in CSF in a large cohort.

Methods: We analysed longitudinal data from adults living with HIV in the US CHARTER cohort. Participants in the CHARTER study were recruited from six US academic medical centres-in Baltimore (MD), Galveston (TX), New York (NY), St Louis (MO), San Diego (C92A), and Seattle (WA). Participants in this study had been assessed at least three times between Sept 4, 2003, and Sept 14, 2010, and were taking ART and underwent venous and lumbar puncture with measurement of HIV RNA concentration at all assessments. The lower limit of quantification of the HIV RNA assays was 50 copies per mL. Data were analysed with longitudinal mixed effects logistic regression to identify correlates of HIV RNA concentration (as a binary [detectable or not] and as a continuous variable) in CSF over time. We tested demographic characteristics, plasma HIV RNA, nadir and current CD4 cell count in blood, current CD8 cell count in blood, estimated duration of HIV infection, AIDS diagnosis, duration of ART, adherence to ART, ART characteristics, and CSF characteristics as potential correlates.

Findings: At the time of analysis, 2207 assessments from 401 participants met the criteria for inclusion in this study. Mean duration of observation was 33·7 months (range 12-84). HIV RNA concentrations in 710 (32·2%) plasma specimens and in 255 (11·6%) CSF specimens were greater than the lower limit of quantification. The best multivariate model of HIV RNA concentration in CSF greater than the lower limit of quantification over time included increased plasma HIV RNA concentration (odds ratio 18·0 per 1 log copy per mL, 95% CI 11·3 to 28·8; p<0·0001), increased CSF leucocyte count (2·01 per 5 cells per μL, 1·61 to 2·39; p<0·0001), decreased CD4 cell count (0·53 per 5 square-root cells per μL, 0·35 to 0·79; p=0·0025), decreased CNS penetration-effectiveness value (0·71 per unit, 0·56 to 0·92; p=0·0078), increased CD8 cell count (1·51 per 5 square-root cells, 1·11 to 2·06; p=0·0089), and protease inhibitor use (3·26, 1·04 to 10·23; p=0·039; model R=0·22, p<0·0001). Analyses of continuous HIV RNA concentration in CSF that accounted for censoring below the lower limit of quantification had similar findings, although increased HIV RNA concentrations in CSF were also associated with black ethnicity (change in log HIV RNA concentration in CSF 0·205, 0·0367 to 0·3733; p=0·017), increased total protein in CSF (0·0025, -0·0002 to 0·0052; p=0·069), and the presence of addictive-drug metabolites in urine (0·103, -0·013 to 0·219; p=0·081).

Interpretation: The identified correlates of HIV RNA concentration in CSF during ART could strengthen clinical prediction of risk for failure to achieve or maintain HIV RNA suppression in CSF. Because most participants in this analysis were ART-experienced and were taking a three-drug regimen that did not include an integrase inhibitor, future research should focus on participants who are taking their first ART regimens or regimens that include integrase inhibitors or two drugs.

Funding: The work was supported by the National Institute of Mental Health and the National Institute of Neurological Disorders and Stroke.
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http://dx.doi.org/10.1016/S2352-3018(19)30143-2DOI Listing
July 2019

Neurocognitive SuperAging in Older Adults Living With HIV: Demographic, Neuromedical and Everyday Functioning Correlates.

J Int Neuropsychol Soc 2019 05 20;25(5):507-519. Epub 2019 Mar 20.

2Department of Psychiatry,University of California,San Diego,San Diego,California.

Objectives: Studies of neurocognitively elite older adults, termed SuperAgers, have identified clinical predictors and neurobiological indicators of resilience against age-related neurocognitive decline. Despite rising rates of older persons living with HIV (PLWH), SuperAging (SA) in PLWH remains undefined. We aimed to establish neuropsychological criteria for SA in PLWH and examined clinically relevant correlates of SA.

Methods: 734 PLWH and 123 HIV-uninfected participants between 50 and 64 years of age underwent neuropsychological and neuromedical evaluations. SA was defined as demographically corrected (i.e., sex, race/ethnicity, education) global neurocognitive performance within normal range for 25-year-olds. Remaining participants were labeled cognitively normal (CN) or impaired (CI) based on actual age. Chi-square and analysis of variance tests examined HIV group differences on neurocognitive status and demographics. Within PLWH, neurocognitive status differences were tested on HIV disease characteristics, medical comorbidities, and everyday functioning. Multinomial logistic regression explored independent predictors of neurocognitive status.

Results: Neurocognitive status rates and demographic characteristics differed between PLWH (SA=17%; CN=38%; CI=45%) and HIV-uninfected participants (SA=35%; CN=55%; CI=11%). In PLWH, neurocognitive groups were comparable on demographic and HIV disease characteristics. Younger age, higher verbal IQ, absence of diabetes, fewer depressive symptoms, and lifetime cannabis use disorder increased likelihood of SA. SA reported increased independence in everyday functioning, employment, and health-related quality of life than non-SA.

Conclusions: Despite combined neurological risk of aging and HIV, youthful neurocognitive performance is possible for older PLWH. SA relates to improved real-world functioning and may be better explained by cognitive reserve and maintenance of cardiometabolic and mental health than HIV disease severity. Future research investigating biomarker and lifestyle (e.g., physical activity) correlates of SA may help identify modifiable neuroprotective factors against HIV-related neurobiological aging. (JINS, 2019, 25, 507-519).
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http://dx.doi.org/10.1017/S1355617719000018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6705613PMC
May 2019

Effects of comorbidity burden and age on brain integrity in HIV.

AIDS 2019 06;33(7):1175-1185

Department of Psychiatry, University of California San Diego, La Jolla.

Objective: The influence of confounding neurocognitive comorbidities in people living with HIV (PLWH) on neuroimaging has not been systematically evaluated. We determined associations between comorbidity burden and brain integrity and examined the moderating effect of age on these relationships.

Design: Observational, cross-sectional substudy of the CNS HIV Antiretroviral Therapy Effects Research cohort.

Methods: A total of 288 PLWH (mean age = 44.2) underwent structural MRI and magnetic resonance spectroscopy as well as neurocognitive and neuromedical assessments. Consistent with Frascati criteria for HIV-associated neurocognitive disorders (HAND), neuromedical and neuropsychiatric comorbidity burden was classified as incidental (mild), contributing (moderate), or confounding (severe-exclusionary) to a diagnosis of HAND. Multiple regression modeling predicted neuroimaging outcomes as a function of comorbidity classification, age, and their interaction.

Results: Comorbidity classifications were 176 incidental, 77 contributing, and 35 confounded; groups did not differ in HIV disease characteristics. Relative to incidental and contributing participants, confounded participants had less cortical gray matter and more abnormal white matter and ventricular cerebrospinal fluid, alongside more neuroinflammation (choline, myo-inositol) and less neuronal integrity (N-acetylaspartate). Older age exacerbated the impact of comorbidity burden: to a greater extent in the confounded group, older age was associated with more abnormal white matter (P = 0.017), less total white matter (P = 0.015), and less subcortical gray matter (P = 0.014).

Conclusion: Neuroimaging in PLWH reveals signatures associated with confounding neurocognitive conditions, emphasizing the importance of evaluating these among individuals with suspected HAND. Older age amplifies subcortical and white matter tissue injury, especially in PLWH with severe comorbidity burden, warranting increased attention to this population as it ages.
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http://dx.doi.org/10.1097/QAD.0000000000002192DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6613389PMC
June 2019

Cerebrospinal fluid viral escape in aviremic HIV-infected patients receiving antiretroviral therapy: prevalence, risk factors and neurocognitive effects.

AIDS 2019 03;33(3):475-481

University of California, San Diego, San Diego, California.

Background: During antiretroviral therapy, HIV RNA can be detected in cerebrospinal fluid (CSF) when it is undetectable in plasma, a condition termed 'CSF viral escape'. The aim of the current study was to determine the prevalence and risk factors for CSF viral escape in two large cohorts in the USA.

Methods: A total of 1264 HIV-infected volunteers enrolled in two US cohorts at their most recent visit between 2003 and 2011 were included in this cross-sectional analysis if their HIV RNA level in plasma was less than 50 copies/ml while receiving stable antiretroviral therapy (ART) (>6 months) and if they had HIV RNA measured in CSF at their most recent visit between 2003 and 2011. Potential risk factors were identified using univariable and multivariable regression.

Results: CSF viral escape was detected in 55 adults (4.4%; 95% CI: 3.4-5.6), who had a median CSF HIV RNA of 155 copies/ml [interquartile range (IQR: 80-283)]. Patients with or without CSF viral escape had similar rates of neurocognitive impairment (38.2 vs. 37.7%; P = 0.91). CSF viral escape was independently associated with the use of ritonavir-boosted protease inhibitors [odds ratio (OR): 2.0; 95% CI: 1.1-3.8] or unboosted atazanavir (OR: 5.1; 95% CI: 1.3-16.1), CSF pleocytosis (OR: 7.6; 95% CI: 4.2-13.7) and abnormal CSF total protein (OR: 2.1; 95% CI: 1.1-3.7).

Conclusions: In this large study of aviremic patients receiving ART, CSF viral escape was uncommon and was linked to evidence of central nervous system inflammation and the use of protease inhibitors, but not with worse neurocognitive performance.
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http://dx.doi.org/10.1097/QAD.0000000000002074DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6361539PMC
March 2019

HIV-induced neuroinflammation: impact of PAR1 and PAR2 processing by Furin.

Cell Death Differ 2019 10 25;26(10):1942-1954. Epub 2019 Jan 25.

Laboratory of Biochemical Neuroendocrinology, Montreal Clinical Research Institute (affiliated to the University of Montreal), 110 Pine Ave West, Montreal, QC, H2W1R7, Canada.

HIV-associated neurocognitive disorders (HAND) is a syndrome defined by neurocognitive deficits that are driven by viral neurotoxins, cytokines, free radicals, and proteases expressed in the brain. This neurological disease has also been linked to activation of Protease-Activated Receptors 1 and 2 (PAR1,2). These receptors are highly expressed in the central nervous system and are upregulated in HAND. Secretory basic-amino-acid-specific Proprotein Convertases (PCs), which cleave precursor proteins at basic residues, are also induced in HAND. They are vital for many biological processes including HIV-1 entry into cells. The cytoprotective role of Furin, PC5, and PACE4 has been linked to the presence of a potential PC-cleavage site RXXXXR↓ in PAR1. Furthermore, Furin binds PAR1 and both are trapped in the trans-Golgi-network (TGN) as inactive proteins, likely due to the intermediary trafficking role of phospho-Furin acidic cluster sorting protein 1 (PACS1). Nothing is known about PAR2 and its possible recognition by PCs at its putative RXXXXR↓ processing site. The present study implicates PACS1 in the retrograde trafficking of PAR1 to the TGN and demonstrates that the cytosolic extreme C-terminal tail of PAR1 contains an acidic phosphorylatable PACS1-sensitive domain. We further show the requirement of Asn in PAR1 for its Furin-dependent TGN localization. Our data revealed that Furin is the only convertase that efficiently cleaves PAR2 at Arg↓. N-glycosylation of PAR2 at Asn reduces the efficacy, but enhances selectivity of the Furin cleavage. Finally, in co-cultures comprised of human neuroblastoma SK-N-SH cells (stably expressing PAR1/2 and/or Furin) and HIV-1-infected primary macrophages, we demonstrate that the expression of Furin enhances neuronal cell viability in the context of PAR1- or PAR2-induced neuronal cytotoxicity. The present study provides insights into early stages of HIV-1 induced neuronal injury and the protective role of Furin in neurons co-expressing PAR1 and/or PAR2, as observed in HAND.
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http://dx.doi.org/10.1038/s41418-018-0264-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6748122PMC
October 2019

White matter damage, neuroinflammation, and neuronal integrity in HAND.

J Neurovirol 2019 02 5;25(1):32-41. Epub 2018 Oct 5.

University of California at San Diego, La Jolla, CA, USA.

HIV-associated neurocognitive disorders (HANDs) persist even with virologic suppression on combination antiretroviral therapy (cART), and the underlying pathophysiological mechanisms are not well understood. We performed structural magnetic resonance imaging and MR spectroscopy (MRS) in HIV+ individuals without major neurocognitive comorbidities. Study participants were classified as neurocognitively unimpaired (NU), asymptomatic (ANI), mild neurocognitive disorder (MND), or HIV-associated dementia (HAD). Using structural MRI, we measured volumes of cortical and subcortical gray matter and total and abnormal white matter (aWM). Using single-voxel MRS, we estimated metabolites in frontal gray matter (FGM) and frontal white matter (FWM) and basal ganglia (BG) regions. Adjusted odds ratios were used to compare HAND to NU. Among 253 participants, 40% met HAND criteria (21% ANI, 15% MND, and 4% HAD). Higher risk of HAND was associated with more aWM. Both HAD and MND also had smaller gray and white matter volumes than NU. Among individuals with undetectable plasma HIV RNA, structural volumetric findings were similar to the overall sample. MND had lower FWM creatine and higher FGM choline relative to NU, whereas HAD and ANI had lower BG N-acetyl aspartate relative to NU. In the virologically suppressed subgroup, however, ANI and MND had higher FGM choline compared to NU. Overall, HAND showed specific alterations (more aWM and inflammation; less gray matter volume and lower NAA). Some MR measures differentiated less severe subtypes of HAND from HAD. These MR alterations may represent legacy effects or accumulating changes, possibly related to medical comorbidities, antiretroviral therapy, or chronic effects of HIV brain infection.
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http://dx.doi.org/10.1007/s13365-018-0682-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6416232PMC
February 2019

Imaging findings in the progression of a giant cell glioblastoma.

Radiol Case Rep 2018 Oct 14;13(5):1007-1011. Epub 2018 Aug 14.

The University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555, USA.

First described in 1909, giant cell glioblastoma (GC) is a histologic variant of glioblastoma multiforme (GBM) that accounts for 1% of cases of primary GBM. It is characterized by a predominance of bizarre giant cells with abundant eosinophilic cytoplasm, and may portend an improved prognosis over classic GBM. Due to the rarity of GC, there is a paucity of reports that describe its associated radiologic findings. This case report chronicles the progression of a GC that was incidentally discovered in a 74-year-old male with coincident subdural hematoma and empyema. Serial brain imaging was obtained as part of this patient's continued work-up that documents the radiologic characteristics of the GC over a period of months. To our knowledge, this manuscript is the most extensive radiologic documentation of the progression of GC to date.
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http://dx.doi.org/10.1016/j.radcr.2018.07.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6097408PMC
October 2018

BACE1 Mediates HIV-Associated and Excitotoxic Neuronal Damage Through an APP-Dependent Mechanism.

J Neurosci 2018 05 9;38(18):4288-4300. Epub 2018 Apr 9.

Department of Pathology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104,

HIV-associated neurocognitive disorders (HANDs) share common symptoms with Alzheimer's disease (AD), which is characterized by amyloid-β (Aβ) plaques. Plaques are formed by aggregation of Aβ oligomers, which may be the toxic species in AD pathogenesis, and oligomers are generated by cleavage of amyloid precursor protein (APP) by β-site amyloid precursor protein cleaving enzyme 1 (BACE1). BACE1 inhibitors reverse neuronal loss and cognitive decline in animal models of AD. Although studies have also found evidence of altered APP processing in HIV patients, it is unknown whether increased BACE1 expression or Aβ oligomer production is a common neuropathological feature of HAND. Moreover, it is unknown whether BACE1 or APP is involved in the excitotoxic, NMDAR-dependent component of HIV-associated neurotoxicity Herein, we hypothesize that HIV-associated neurotoxicity is mediated by NMDAR-dependent elevation of BACE1 and subsequent altered processing of APP. Supporting this, we observed elevated levels of BACE1 and Aβ oligomers in CNS of male and female HIV patients. In a model of HIV-associated neurotoxicity in which rat neurons are treated with supernatants from HIV-infected human monocyte-derived macrophages, we observed NMDAR-dependent elevation of BACE1 protein. NMDA treatment also increased BACE1 and both pharmacological BACE1 inhibition and genetic loss of APP were partially neuroprotective. Moreover, in APP knock-out (APP) mouse neurons, NMDA-induced toxicity was BACE1 independent, indicating that cytotoxicity of BACE1 is dependent upon APP cleavage. Our findings suggest that increased BACE1 and the resultant Aβ oligomer production may contribute to HIV-associated neuropathogenesis and inhibition of BACE1 could have therapeutic potential in HANDs. HIV-associated neurocognitive disorders (HANDs) represent a range of cognitive impairments affecting ∼50% of HIV individuals. The specific causes of HAND are unknown, but evidence suggests that HIV-infected macrophage infiltration into the brain may cause neuronal damage. Herein, we show that neurons treated with conditioned media from HIV-infected macrophages have increased expression of β-site amyloid precursor protein cleaving enzyme 1 (BACE1), a protein implicated in Alzheimer's disease pathogenesis. Moreover, inhibition of BACE1 prevented neuronal loss after conditioned media exposure, but had no effect on HIV-associated neurotoxicity in neurons lacking its cleavage target amyloid precursor protein. We also observed increased BACE1 expression in HIV patient brain tissue, confirming the potential relevance of BACE1 as a therapeutic target in HANDs.
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http://dx.doi.org/10.1523/JNEUROSCI.1280-17.2018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5932640PMC
May 2018

Heme oxygenase-1 promoter region (GT)n polymorphism associates with increased neuroimmune activation and risk for encephalitis in HIV infection.

J Neuroinflammation 2018 Mar 6;15(1):70. Epub 2018 Mar 6.

Department of Neurology, Perelman School of Medicine, University of Pennsylvania, 415 Curie Boulevard, 280C Clinical Research Building, Philadelphia, PA, 19104, USA.

Background: Heme oxygenase-1 (HO-1) is a critical cytoprotective enzyme that limits oxidative stress, inflammation, and cellular injury within the central nervous system (CNS) and other tissues. We previously demonstrated that HO-1 protein expression is decreased within the brains of HIV+ subjects and that this HO-1 reduction correlates with CNS immune activation and neurocognitive dysfunction. To define a potential CNS protective role for HO-1 against HIV, we analyzed a well-characterized HIV autopsy cohort for two common HO-1 promoter region polymorphisms that are implicated in regulating HO-1 promoter transcriptional activity, a (GT)n dinucleotide repeat polymorphism and a single nucleotide polymorphism (A(-413)T). Shorter HO-1 (GT)n repeats and the 'A' SNP allele associate with higher HO-1 promoter activity.

Methods: Brain dorsolateral prefrontal cortex tissue samples from an autopsy cohort of HIV-, HIV+, and HIV encephalitis (HIVE) subjects (n = 554) were analyzed as follows: HO-1 (GT)n polymorphism allele lengths were determined by PCR and capillary electrophoresis, A(-413)T SNP alleles were determined by PCR with allele specific probes, and RNA expression of selected neuroimmune markers was analyzed by quantitative PCR.

Results: HIV+ subjects with shorter HO-1 (GT)n alleles had a significantly lower risk of HIVE; however, shorter HO-1 (GT)n alleles did not correlate with CNS or peripheral viral loads. In HIV+ subjects without HIVE, shorter HO-1 (GT)n alleles associated significantly with lower expression of brain type I interferon response markers (MX1, ISG15, and IRF1) and T-lymphocyte activation markers (CD38 and GZMB). No significant correlations were found between the HO-1 (GT)n repeat length and brain expression of macrophage markers (CD163, CD68), endothelial markers (PECAM1, VWF), the T-lymphocyte marker CD8A, or the B-lymphocyte maker CD19. Finally, we found no significant associations between the A(-413)T SNP and HIVE diagnosis, HIV viral loads, or any neuroimmune markers.

Conclusion: Our data suggest that an individual's HO-1 promoter region (GT)n polymorphism allele repeat length exerts unique modifying risk effects on HIV-induced CNS neuroinflammation and associated neuropathogenesis. Shorter HO-1 (GT)n alleles increase HO-1 promoter activity, which could provide neuroprotection through decreased neuroimmune activation. Therapeutic strategies that induce HO-1 expression could decrease HIV-associated CNS neuroinflammation and decrease the risk for development of HIV neurological disease.
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http://dx.doi.org/10.1186/s12974-018-1102-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5838989PMC
March 2018

When do models of NeuroAIDS faithfully imitate "the real thing"?

J Neurovirol 2018 04 18;24(2):146-155. Epub 2017 Dec 18.

Department of Neurology, University of Pennsylvania, Philadelphia, PA, 19104-6140, USA.

HIV-infected patients treated with antiretroviral medicines (ART) still face neurological challenges. HIV-associated neurocognitive disturbances (HAND) can occur, and latent viral DNA persisting in the central nervous system (CNS) prevents eradication of HIV. This communication focuses on how to develop experimental models of HAND and CNS HIV latency that best imitate the CNS pathophysiology in diseased humans, which we take to be "the real thing." Models of HIV encephalitis (HIVE) with active CNS viral replication were developed in the early years of the AIDS pandemic. The clinical relevancy of such models is in sharp decline because HIVE seldom occurs in virally suppressed patients, while HAND remains common. The search for improved models of HAND should incorporate the neurochemical, neuroimmunological and neuropathological features of virally suppressed patients. Common anomalies in these patients as established in autopsy brain specimens include brain endothelial cell activation and neurochemical imbalances of synaptic transmission; classical neurodegeneration may not be as crucial. With regard to latent HIV with viral suppression, human brain specimens show that the pool of latent proviral HIV DNA in the CNS is relatively small relative to the total body pool and does not change substantially over years. The CNS pool of latent virus probably differs from lymphoid tissues, because the mononuclear phagocyte system sustains productive infection (versus lymphocytes). These and yet-to-be discovered aspects of the human CNS of virally suppressed patients need to be better defined and addressed in experimental models. To maintain clinical relevancy, models of HAND and viral latency should faithfully emulate "the real thing."
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http://dx.doi.org/10.1007/s13365-017-0601-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5910470PMC
April 2018

Friedreich Ataxia: Developmental Failure of the Dorsal Root Entry Zone.

J Neuropathol Exp Neurol 2017 Nov;76(11):969-977

Research Service, Veterans Affairs Medical Center, Albany, New York; Department of Pathology, Albany Medical College, Albany, New York; Department of Pathology and Laboratory Medicine, University of Texas Medical Branch, Galveston, Texas; Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York.

Dorsal root ganglia, dorsal roots (DR), and dorsal root entry zones (DREZ) are vulnerable to frataxin deficiency in Friedreich ataxia (FA). A previously unrecognized abnormality is the intrusion of astroglial tissue into DR. Segments of formalin-fixed upper lumbar spinal cord of 13 homozygous and 2 compound heterozygous FA patients were sectioned longitudinally to represent DREZ and stained for glial fibrillary acidic protein (GFAP), S100, vimentin, the central nervous system (CNS)-specific myelin protein proteolipid protein, the peripheral nervous system (PNS) myelin proteins PMP-22 and P0, and the Schwann cell proteins laminin, alpha-dystroglycan, and periaxin. Normal DREZ showed short, sharply demarcated, dome-like extensions of CNS tissue into DR. The Schwann cell-related proteins formed tight caps around these domes. In FA, GFAP-, S100-, and vimentin-reactive CNS tissue extended across DREZ and into DR over much longer distances by breaching the CNS-PNS barrier. The transition between PNS and CNS myelin proteins was disorganized. During development, neural-crest derived boundary cap cells provide guidance to dorsal root ganglia axons growing into the dorsal spinal cord and at the same time block the inappropriate intrusion of CNS glia into DR. It is likely that frataxin is required during a critical period of permissive (axons) and nonpermissive (astroglia) border-control.
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http://dx.doi.org/10.1093/jnen/nlx087DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6440497PMC
November 2017

Differences in Neurocognitive Impairment Among HIV-Infected Latinos in the United States.

J Int Neuropsychol Soc 2018 02 6;24(2):163-175. Epub 2017 Sep 6.

1Department of Psychiatry,University of California,San Diego,California.

Objectives: Human immunodeficiency virus (HIV) disproportionately affects Hispanics/Latinos in the United States, yet little is known about neurocognitive impairment (NCI) in this group. We compared the rates of NCI in large well-characterized samples of HIV-infected (HIV+) Latinos and (non-Latino) Whites, and examined HIV-associated NCI among subgroups of Latinos.

Methods: Participants included English-speaking HIV+ adults assessed at six U.S. medical centers (194 Latinos, 600 Whites). For overall group, age: M=42.65 years, SD=8.93; 86% male; education: M=13.17, SD=2.73; 54% had acquired immunodeficiency syndrome. NCI was assessed with a comprehensive test battery with normative corrections for age, education and gender. Covariates examined included HIV-disease characteristics, comorbidities, and genetic ancestry.

Results: Compared with Whites, Latinos had higher rates of global NCI (42% vs. 54%), and domain NCI in executive function, learning, recall, working memory, and processing speed. Latinos also fared worse than Whites on current and historical HIV-disease characteristics, and nadir CD4 partially mediated ethnic differences in NCI. Yet, Latinos continued to have more global NCI [odds ratio (OR)=1.59; 95% confidence interval (CI)=1.13-2.23; p<.01] after adjusting for significant covariates. Higher rates of global NCI were observed with Puerto Rican (n=60; 71%) versus Mexican (n=79, 44%) origin/descent; this disparity persisted in models adjusting for significant covariates (OR=2.40; CI=1.11-5.29; p=.03).

Conclusions: HIV+ Latinos, especially of Puerto Rican (vs. Mexican) origin/descent had increased rates of NCI compared with Whites. Differences in rates of NCI were not completely explained by worse HIV-disease characteristics, neurocognitive comorbidities, or genetic ancestry. Future studies should explore culturally relevant psychosocial, biomedical, and genetic factors that might explain these disparities and inform the development of targeted interventions. (JINS, 2018, 24, 163-175).
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http://dx.doi.org/10.1017/S1355617717000832DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5777885PMC
February 2018

Heart and Nervous System Pathology in Compound Heterozygous Friedreich Ataxia.

J Neuropathol Exp Neurol 2017 Aug;76(8):665-675

Research Service, Veterans Affairs Medical Center, Albany, New York (ABB, AHK); Department of Pathology, Albany Medical Center, Albany, New York (JQ, AHK); Department of Pathology and Laboratory Medicine, University of Texas Medical Branch, Galveston, Texas (BBG); Department of Pediatrics and Neurology, University of Colorado, Aurora, Colorado (MY); and Centogene, Rostock, Germany (PB).

In a small percentage of patients with Friedreich ataxia (FA), the pathogenic mutation is compound heterozygous, consisting of a guanine-adenine-adenine (GAA) trinucleotide repeat expansion in one allele, and a deletion, point mutation, or insertion in the other. In 2 cases of compound heterozygous FA, the GAA expansion was inherited from the mother, and deletions from the father. Compound heterozygous FA patient 1, an 11-year-old boy (GAA, 896/c.11_12TCdel), had ataxia, chorea, cardiomyopathy, and diabetes mellitus. Compound heterozygous FA patient 2, a 28-year-old man (GAA, 744/exon 5 del), had ataxia, cardiomyopathy, and diabetes mellitus. Microscopy showed cardiomyocyte hypertrophy, iron-positive inclusions, and disrupted intercalated discs. The cardiac lesions were similar to those in age-matched homozygous FA patients with cardiomyopathy and diabetes mellitus (boy, 10, GAA 1016/1016; woman, 25, GAA 800/1100). The neuropathology was also similar and included hypoplasia of spinal cord and dorsal root ganglia, loss of large axons in dorsal roots, and atrophy of the dentate nucleus (DN). Frataxin levels in heart and DN of all 4 FA cases were at or below the detection limits of the enzyme-linked immunosorbent assay (≤10 ng/g wet weight) (normal DN: 126 ± 43 ng/g; normal heart: 266 ± 92 ng/g). The pathologic phenotype in homozygous and compound heterozygous FA is determined by residual frataxin levels rather than unique mutations.
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http://dx.doi.org/10.1093/jnen/nlx047DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5901083PMC
August 2017

MicroRNAs upregulated during HIV infection target peroxisome biogenesis factors: Implications for virus biology, disease mechanisms and neuropathology.

PLoS Pathog 2017 Jun 8;13(6):e1006360. Epub 2017 Jun 8.

Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada.

HIV-associated neurocognitive disorders (HAND) represent a spectrum neurological syndrome that affects up to 25% of patients with HIV/AIDS. Multiple pathogenic mechanisms contribute to the development of HAND symptoms including chronic neuroinflammation and neurodegeneration. Among the factors linked to development of HAND is altered expression of host cell microRNAs (miRNAs) in brain. Here, we examined brain miRNA profiles among HIV/AIDS patients with and without HAND. Our analyses revealed differential expression of 17 miRNAs in brain tissue from HAND patients. A subset of the upregulated miRNAs (miR-500a-5p, miR-34c-3p, miR-93-3p and miR-381-3p), are predicted to target peroxisome biogenesis factors (PEX2, PEX7, PEX11B and PEX13). Expression of these miRNAs in transfected cells significantly decreased levels of peroxisomal proteins and concomitantly decreased peroxisome numbers or affected their morphology. The levels of miR-500a-5p, miR-34c-3p, miR-93-3p and miR-381-3p were not only elevated in the brains of HAND patients, but were also upregulated during HIV infection of primary macrophages. Moreover, concomitant loss of peroxisomal proteins was observed in HIV-infected macrophages as well as in brain tissue from HIV-infected patients. HIV-induced loss of peroxisomes was abrogated by blocking the functions of the upregulated miRNAs. Overall, these findings point to previously unrecognized miRNA expression patterns in the brains of HIV patients. Targeting peroxisomes by up-regulating miRNAs that repress peroxisome biogenesis factors may represent a novel mechanism by which HIV-1 subverts innate immune responses and/or causes neurocognitive dysfunction.
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http://dx.doi.org/10.1371/journal.ppat.1006360DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5464672PMC
June 2017

Degradation of heme oxygenase-1 by the immunoproteasome in astrocytes: A potential interferon-γ-dependent mechanism contributing to HIV neuropathogenesis.

Glia 2017 08 22;65(8):1264-1277. Epub 2017 May 22.

Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, 19104.

Induction of the detoxifying enzyme heme oxygenase-1 (HO-1) is a critical protective host response to cellular injury associated with inflammation and oxidative stress. We previously found that HO-1 protein expression is reduced in brains of HIV-infected individuals with HIV-associated neurocognitive disorders (HAND) and in HIV-infected macrophages, where this reduction associates with enhanced glutamate release and neurotoxicity. Because HIV-infected macrophages are a small component of the cellular content of the brain, the reduction of macrophage HO-1 expression likely accounts for a small portion of brain HO-1 loss in HIV infection. We therefore investigated the contribution of astrocytes, the major pool of brain HO-1. We identified immunoproteasome-mediated HO-1 degradation in astrocytes as a second possible mechanism of brain HO-1 loss in HIV infection. We demonstrate that prolonged exposure of human fetal astrocytes to interferon-gamma (IFNγ), an HIV-associated CNS immune activator, selectively reduces expression of HO-1 protein without a concomitant reduction in HO-1 RNA, increases expression of immunoproteasome subunits, and decreases expression of constitutive proteasome subunits, consistent with a shift towards increased immunoproteasome activity. In HIV-infected brain HO-1 protein reduction also associates with increased HO-1 RNA expression and increased immunoproteasome expression. Finally, we show that IFNγ treatment of astrocytic cells reduces HO-1 protein half-life in a proteasome-dependent manner. Our data thus suggest unique causal links among HIV infection, IFNγ-mediated immunoproteasome induction, and enhanced HO-1 degradation, which likely contribute to neurocognitive impairment in HAND. Such IFNγ-mediated HO-1 degradation should be further investigated for a role in neurodegeneration in inflammatory brain conditions.

Brief Summary: Kovacsics et al. identify immunoproteasome degradation of heme oxygenase-1 (HO-1) in interferon gamma-stimulated astrocytes as a plausible mechanism for the observed loss of HO-1 protein expression in the brains of HIV-infected individuals, which likely contributes to the neurocognitive impairment in HIV-associated neurocognitive disorders.
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http://dx.doi.org/10.1002/glia.23160DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5739592PMC
August 2017

Modeling brain lentiviral infections during antiretroviral therapy in AIDS.

J Neurovirol 2017 08 16;23(4):577-586. Epub 2017 May 16.

Division of Neurology, Department of Medicine, University of Alberta, Edmonton, Canada.

Understanding HIV-1 replication and latency in different reservoirs is an ongoing challenge in the care of patients with HIV/AIDS. A mathematical model was created to describe and predict the viral dynamics of HIV-1 and SIV infection within the brain during effective combination antiretroviral therapy (cART). The mathematical model was formulated based on the biology of lentiviral infection of brain macrophages and used to describe the dynamics of transmission and progression of lentiviral infection in brain. Based on previous reports quantifying total viral DNA levels in brain from HIV-1 and SIV infections, estimates of integrated proviral DNA burden were made, which were used to calibrate the mathematical model predicting viral accrual in brain macrophages from primary infection. The annual rate at which susceptible brain macrophages become HIV-1 infected was estimated to be 2.90×10-4.87×10 per year for cART-treated HIV/AIDS patients without comorbid neurological disorders. The transmission rate for SIV infection among untreated macaques was estimated to be 5.30×10-1.37×10 per year. An improvement in cART effectiveness (1.6-48%) would suppress HIV-1 infection in patients without neurological disorders. Among patients with advanced disease, a substantial improvement in cART effectiveness (70%) would eradicate HIV-1 provirus from the brain within 3-32 (interquartile range 3-9) years in patients without neurological disorders, whereas 4-51 (interquartile range 4-16) years of efficacious cART would be required for HIV/AIDS patients with comorbid neurological disorders. HIV-1 and SIV provirus burdens in the brain increase over time. A moderately efficacious antiretroviral therapy regimen could eradicate HIV-1 infection in the brain that was dependent on brain macrophage lifespan and the presence of neurological comorbidity.
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http://dx.doi.org/10.1007/s13365-017-0530-3DOI Listing
August 2017

Genome-wide association study of HIV-associated neurocognitive disorder (HAND): A CHARTER group study.

Am J Med Genet B Neuropsychiatr Genet 2017 Jun 26;174(4):413-426. Epub 2017 Apr 26.

Department of Genomic Medicine, Lerner Research Institute and Department of Medicine, Cleveland Clinic, Cleveland, Ohio.

HIV-associated neurocognitive disorder (HAND) often complicates HIV infection despite combination antiretroviral therapy (ART) and may be influenced by host genomics. We performed a genome-wide association study (GWAS) of HAND in 1,050 CNS HIV Anti-Retroviral Therapy Effects Research (CHARTER) Study participants. All participants underwent standardized, comprehensive neurocognitive, and neuromedical assessments to determine if they had cognitive impairment as assessed by the Global Deficit Score (GDS), and individuals with comorbidities that could confound diagnosis of HAND were excluded. Neurocognitive outcomes included GDS-defined neurocognitive impairment (NCI; binary GDS, 366 cases with GDS ≥ 0.5 and 684 controls with GDS < 0.5, and GDS as a continuous variable) and Frascati HAND definitions that incorporate assessment of functional impairment by self-report and performance-based criteria. Genotype data were obtained using the Affymetrix Human SNP Array 6.0 platform. Multivariable logistic or linear regression-based association tests were performed for GDS-defined NCI and HAND. GWAS results did not reveal SNPs meeting the genome-wide significance threshold (5.0 × 10 ) for GDS-defined NCI or HAND. For binary GDS, the most significant SNPs were rs6542826 (P = 8.1 × 10 ) and rs11681615 (1.2 × 10 ), both located on chromosome 2 in SH3RF3. The most significant SNP for continuous GDS was rs11157436 (P = 1.3 × 10 ) on chromosome 14 in the T-cell-receptor alpha locus; three other SNPs in this gene were also associated with binary GDS (P ≤ 2.9 × 10 ). This GWAS, conducted among ART-era participants from a single cohort with robust neurological phenotyping, suggests roles for several biologically plausible loci in HAND that deserve further exploration. © 2017 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/ajmg.b.32530DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5435520PMC
June 2017

Cerebrospinal fluid cell-free mitochondrial DNA is associated with HIV replication, iron transport, and mild HIV-associated neurocognitive impairment.

J Neuroinflammation 2017 03 31;14(1):72. Epub 2017 Mar 31.

Genomic Medicine Institute/Lerner Research Institute Cleveland Clinic, Cleveland, OH, USA.

Background: Mitochondria are abundant organelles critical for energy metabolism and brain function. Mitochondrial DNA (mtDNA), released during cellular injury and as part of the innate immune response to viral pathogens, contains CpG motifs that act as TLR-9 ligands. We investigated relationships between cerebrospinal fluid (CSF) cell-free mtDNA levels and HIV viral load (VL), biomarkers of inflammation and iron transport, and neurocognitive (NC) function in the CNS HIV Antiretroviral Therapy Effects Research (CHARTER) cohort.

Methods: We quantified cell-free mtDNA in CSF by droplet digital PCR in 332 CHARTER participants who underwent comprehensive neuropsychiatric evaluation. NC performance was assessed using the global deficit score (GDS) as either a continuous or a binary measure (GDS ≥ 0.5, impaired vs. GDS < 0.5, unimpaired). CSF, clinical, and biomarker data from the earliest available time point were analyzed. Cell-free mtDNA associations with CSF inflammation and iron-related biomarkers [CXCL10, IL-6, IL-8, TNF-a, transferrin (TF), ceruloplasmin (CP), and vascular endothelial growth factor (VEGF)], VL, and GDS were evaluated by multivariable regression.

Results: CSF cell-free mtDNA levels were significantly lower in participants with undetectable (vs. detectable) VL in either plasma (p < 0.001) or CSF (p < 0.001) and in those on antiretroviral therapy (ART; p < 0.001). Participants on ART with undetectable VL in both CSF and plasma had lower mtDNA levels than those with detectable VL in both compartments (p = 0.001). Higher mtDNA levels were observed in participants in the highest vs. lowest tertile (T3 vs. T1) of CSF CXCL10 (T3 vs. T1, p < 0.001) and TNF-a (T3 vs. T1, p < 0.05) in unadjusted analyses. MtDNA levels also correlated with CSF leukocyte count. After adjusting for CSF leukocyte count and VL, mtDNA levels were also associated with other inflammation- and iron-related biomarkers in CSF, including TF (T3 vs. T1, p < 0.05) and CP (T3 vs. T1, p < 0.05). With additional correction for ART use, mtDNA was also negatively associated with CSF VEGF (p < 0.05) and IL-6 (p = 0.05). We observed no associations of CSF mtDNA levels with age or GDS-defined NC impairment.

Conclusions: CSF cell-free mtDNA levels were associated with HIV RNA and ART status, as well as with biomarkers of iron transport and VEGF, a growth factor with known effects on mitochondrial integrity and autophagy. CSF mtDNA may be a biomarker of iron dysregulation and/or neuroinflammation during HIV infection.
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http://dx.doi.org/10.1186/s12974-017-0848-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5374652PMC
March 2017