Molecularly defined cortical astroglia subpopulation modulates neurons via secretion of Norrin

Despite expanding knowledge regarding the role of astroglia in regulating neuronal function, little is known about regional or functional subgroups of brain astroglia and how they may interact with neurons. We use an astroglia-specific promoter fragment in transgenic mice to identify an anatomically defined subset of adult gray matter astroglia. Using transcriptomic and histological analyses, we generate a combinatorial profile for the in vivo identification and characterization of this astroglia subpopulation. These astroglia are enriched in mouse cortical layer V; express distinct molecular markers, including Norrin and leucine-rich repeat-containing G-protein-coupled receptor 6 (LGR6), with corresponding layer-specific neuronal ligands; are found in the human cortex; and modulate neuronal activity. Astrocytic Norrin appears to regulate dendrites and spines; its loss, as occurring in Norrie disease, contributes to cortical dendritic spine loss. These studies provide evidence that human and rodent astroglia subtypes are regionally and functionally distinct, can regulate local neuronal dendrite and synaptic spine development, and contribute to disease.

Lipidomic characterization of extracellular vesicles in human serum

There is a wide variety of extracellular vesicles (EVs) that differ in size and cargo composition. EVs isolated from human plasma or serum carry lipid, protein, and RNA cargo that provides insights to the regulation of normal physiological processes, and to pathological states. Specific populations of EVs have been proposed to contain protein and RNA cargo that are biomarkers for neurologic and systemic diseases. Although there is a considerable amount of evidence that circulating lipids are biomarkers for multiple disease states, it not clear if these lipid biomarkers are enriched in EVs, or if specific populations of EVs are enriched for particular classes of lipid. A highly reproducible workflow for the analysis of lipid content in EVs isolated from human plasma or serum would facilitate this area of research. Here we optimized an MS/MSALL workflow for the untargeted analysis of the lipid content in EVs isolated from human serum. A simple sequential ultracentrifugation protocol isolated three distinct types of serum EVs that were identified based on size, targeted protein, and untargeted lipidomic analyses. EVs in the upper and middle fractions were approximately 140 nm in diameter, while EVs in the pellet were approximately 110 nm in diameter. EVs in the upper most buoyant fractions contained the highest concentration of lipids, were enriched with phospholipids, and immunopositive for the cytoskeletal markers actin, α-actinin, and the mitochondrial protein mitofillin, but negative for the typical EV markers CD63, TSG101, and flotillin. A central fraction of EVs was devoid of cytoskeletal and mitochondrial markers, and positive for CD63, and TSG101, but negative for flotillin. The EV pellet contained no cytoskeletal or mitochondrial markers, but was positive for CD63, TSG101, and flotillin. The EV pellet contained the lowest concentration of most lipids, but was enriched with ceramide. These results provided new insights into the lipid composition of EVs isolated from serum using a simple ultracentrifugation isolation method suitable for lipidomic analysis by mass spectrometry.

Monocarboxylate transporter 1 in Schwann cells contributes to maintenance of sensory nerve myelination during aging

Schwann cell (SC)-specific monocarboxylate transporter 1 (MCT1) knockout mice were generated by mating MCT1 ^f/f mice with myelin protein zero (P0)-Cre mice. P0-Cre^+/- , MCT1 ^f/f mice have no detectable early developmental defects, but develop hypomyelination and reduced conduction velocity in sensory, but not motor, peripheral nerves during maturation and aging. Furthermore, reduced mechanical sensitivity is evident in aged P0-Cre^+/- , MCT1 ^f/f mice. MCT1 deletion in SCs impairs both their glycolytic and mitochondrial functions, leading to altered lipid metabolism of triacylglycerides, diacylglycerides, and sphingomyelin, decreased expression of myelin-associated glycoprotein, and increased expression of c-Jun and p75-neurotrophin receptor, suggesting a regression of SCs to a less mature developmental state. Taken together, our results define the contribution of SC MCT1 to both SC metabolism and peripheral nerve maturation and aging.

Astrocytes deliver CK1 to neurons via extracellular vesicles in response to inflammation promoting the translation and amyloidogenic processing of APP

Chronic inflammation is thought to contribute to the early pathogenesis of Alzheimer's disease (AD). However, the precise mechanism by which inflammatory cytokines promote the formation and deposition of Aβ remains unclear. Available data suggest that applications of inflammatory cytokines onto isolated neurons do not promote the formation of Aβ, suggesting an indirect mechanism of action. Based on evidence astrocyte derived extracellular vesicles (astrocyte derived EVs) regulate neuronal functions, and data that inflammatory cytokines can modify the molecular cargo of astrocyte derived EVs, we sought to determine if IL-1β promotes the formation of Aβ indirectly through actions of astrocyte derived EVs on neurons. The production of Aβ was increased when neurons were exposed to astrocyte derived EVs shed in response to IL-1β (astrocyte derived EV-IL-1β). The mechanism for this effect involved an enrichment of Casein kinase 1 (CK1) in astrocyte derived EV-IL-1β. This astrocyte derived CK1 was delivered to neurons where it formed a complex with neuronal APC and GSK3 to inhibit the β-catenin degradation. Stabilized β-catenin translocated to the nucleus and bound to Hnrnpc gene at promoter regions. An increased cellular concentration of hnRNP C promoted the translation of APP by outcompeting the translational repressor fragile X mental retardation protein (FMRP) bound to APP mRNA. An increased amount of APP protein became co-localized with BACE1 in enlarged membrane microdomains concurrent with increased production of Aβ. These findings identify a mechanism whereby inflammation promotes the formation of Aβ through the actions of astrocyte derived EV-IL-1β on neurons.

Patterns and Predictors of Cognitive Function Among Virally Suppressed Women With HIV

Cognitive impairment remains frequent and heterogeneous in presentation and severity among virally suppressed (VS) women with HIV (WWH). We identified cognitive profiles among 929 VS-WWH and 717 HIV-uninfected women from 11 Women's Interagency HIV Study sites at their first neuropsychological (NP) test battery completion comprised of: Hopkins Verbal Learning Test-Revised, Trail Making, Symbol Digit Modalities, Grooved Pegboard, Stroop, Letter/Animal Fluency, and Letter-Number Sequencing. Using 17 NP performance metrics (T-scores), we used Kohonen self-organizing maps to identify patterns of high-dimensional data by mapping participants to similar nodes based on T-scores and clustering those nodes. Among VS-WWH, nine clusters were identified (entropy = 0.990) with four having average T-scores ≥45 for all metrics and thus combined into an "unimpaired" profile (n = 311). Impaired profiles consisted of weaknesses in: (1) sequencing (Profile-1; n = 129), (2) speed (Profile-2; n = 144), (3) learning + recognition (Profile-3; n = 137), (4) learning + memory (Profile-4; n = 86), and (5) learning + processing speed + attention + executive function (Profile-5; n = 122). Sociodemographic, behavioral, and clinical variables differentiated profile membership using Random Forest models. The top 10 variables distinguishing the combined impaired vs. unimpaired profiles were: clinic site, age, education, race, illicit substance use, current and nadir CD4 count, duration of effective antiretrovirals, and protease inhibitor use. Additional variables differentiating each impaired from unimpaired profile included: depression, stress-symptoms, income (Profile-1); depression, employment (Profile 2); depression, integrase inhibitor (INSTI) use (Profile-3); employment, INSTI use, income, atazanavir use, non-ART medications with anticholinergic properties (Profile-4); and marijuana use (Profile-5). Findings highlight consideration of NP profile heterogeneity and potential modifiable factors contributing to impaired profiles.

Cognitive Trajectory Phenotypes in Human Immunodeficiency Virus-Infected Patients

OBJECTIVE

The presentation of cognitive impairments in HIV-infected individuals has transformed since the introduction of antiretroviral therapies. Although the overall prevalence of cognitive impairments has not changed considerably, frank dementia is now infrequent, and milder forms of cognitive impairments predominate. Mechanistic insights to the underlying causes of these residual cognitive impairments have been elusive, in part due to the heterogenous etiology of cognitive dysfunction in this population. Here, we sought to categorize longitudinal change in HIV-infected patients based on the performance in specific cognitive domains.

DESIGN

This study consisted of 193 participants from the CHARTER cohort with detailed demographic, clinical, and neuropsychological testing data obtained from 2 study visits interspersed by ∼6 months. Cognitive testing assessed executive function, learning and delayed recall, working memory, verbal fluency, speed of information processing, and motor skills. Change scores were calculated for each domain between the 2 study visits. Dimension reduction and clustering was accomplished by principal component analysis of change scores and k-means clustering to identify cognitive domains that group together and groups of subjects with similar patterns of change.

RESULTS

We identified 4 distinct cognitive change phenotypes that included declines in: (1) verbal fluency, (2) executive function (3) learning and recall, and (4) motor function, with approximately equal numbers of participants in each phenotype.

CONCLUSIONS

Each of the 4 cognitive change phenotypes identify deficits that imply perturbations in specific neural networks. Future studies will need to validate if cognitive change phenotypes are associated with alterations in associated neural pathways.

Sex Differences in the Patterns and Predictors of Cognitive Function in HIV

Despite advancements in antiretroviral therapy, mild cognitive deficits persist in nearly half of people with HIV (PWH). The profile of impairment in HIV is highly variable with deficits observed in a range of cognitive domains. Despite evidence of greater cognitive impairment among women with HIV (WWH) vs. men with HIV (MWH), it is unclear how MWH and WWH differ in the type of cognitive impairment and in risk factors associated with cognitive impairment profiles. In a large and well-characterized sample of PWH, we used machine learning to identify profiles of cognitive functioning and their associated factors overall and within sex. Participants included 1,666 PWH (201 WWH; 1,465 MMH) from the HIV Neurobehavioral Research Program who completed a neuropsychological test battery at their baseline visits. Using demographically-adjusted T-scores from 13 test outcomes assessing motor skills, executive functioning, attention/working memory, episodic learning and memory, verbal fluency, and processing speed, we used Kohonen self-organizing maps to identify patterns of high-dimensional data by mapping participants to similar nodes based on T-scores (MCLUST R package). Random forest models were used to determine how sociodemographic (e.g., age, education), clinical (e.g., depressive symptoms, substance use disorder), and biological (e.g., HIV disease characteristics) factors differentially related to membership within a cognitive profile. All analyses were repeated within sex. Three cognitive profiles were identified overall and within each sex. Overall and within MWH, there were unimpaired and global weakness profiles. The third profile in the total sample demonstrated relatively weak auditory attention whereas in MWH showed relative strengths in attention and processing speed. Conversely, there was no unimpaired profile among WWH. Rather, WWH demonstrated separate profiles reflecting weakness in motor skills, a relative weakness in learning and delayed recall, and global weaknesses with spared recognition memory. Despite different cognitive profiles by sex, the most discriminative factors were similar between men and women and included reading level (cognitive reserve), current and nadir CD4 count, plasma HIV viral load, duration of HIV disease, age, depressive symptoms, and race/ethnicity. Findings fill a knowledge gap concerning sex differences in cognitive impairment in PWH and inform personalized risk reduction and therapeutic strategies.

Role of Human-Induced Pluripotent Stem Cell-Derived Spinal Cord Astrocytes in the Functional Maturation of Motor Neurons in a Multielectrode Array System

The ability to generate human‐induced pluripotent stem cell (hiPSC)‐derived neural cells displaying region‐specific phenotypes is of particular interest for modeling central nervous system biology in vitro. We describe a unique method by which spinal cord hiPSC‐derived astrocytes (hiPSC‐A) are cultured with spinal cord hiPSC‐derived motor neurons (hiPSC‐MN) in a multielectrode array (MEA) system to record electrophysiological activity over time. We show that hiPSC‐A enhance hiPSC‐MN electrophysiological maturation in a time‐dependent fashion. The sequence of plating, density, and age in which hiPSC‐A are cocultured with MN, but not their respective hiPSC line origin, are factors that influence neuronal electrophysiology. When compared to coculture with mouse primary spinal cord astrocytes, we observe an earlier and more robust electrophysiological maturation in the fully human cultures, suggesting that the human origin is relevant to the recapitulation of astrocyte/motor neuron crosstalk. Finally, we test pharmacological compounds on our MEA platform and observe changes in electrophysiological activity, which confirm hiPSC‐MN maturation. These findings are supported by immunocytochemistry and real‐time PCR studies in parallel cultures demonstrating human astrocyte mediated changes in the structural maturation and protein expression profiles of the neurons. Interestingly, this relationship is reciprocal and coculture with neurons influences astrocyte maturation as well. Taken together, these data indicate that in a human in vitro spinal cord culture system, astrocytes support hiPSC‐MN maturation in a time‐dependent and species‐specific manner and suggest a closer approximation of in vivo conditions. stem cells translational medicine2019;8:1272&1285

We describe a fully human, spinal cord‐specific, coculture platform with human‐induced pluripotent stem cell‐derived motor neurons and astrocytes for multielectrode array recording. We show that human‐induced pluripotent stem cell‐derived motor neurons/human‐induced pluripotent stem cell‐derived astrocytes bidirectional morphological and molecular maturation is reflected by electrophysiological recordings with multielectrode array recording.

Heterogeneity in neurocognitive change trajectories among people with HIV starting antiretroviral therapy in Rakai, Uganda

Considerable heterogeneity exists in patterns of neurocognitive change in people with HIV (PWH). We examined heterogeneity in neurocognitive change trajectories from HIV diagnosis to 1-2 years post-antiretroviral therapy (ART). In an observational cohort study in Rakai, Uganda, 312 PWH completed a neuropsychological (NP) test battery at two-time points (ART-naïve, 1-2 years post-ART initiation). All NP outcomes were used in a latent profile analysis to identify subgroups of PWH with similar ART-related neurocognitive change profiles. In a subset, we examined subgroup differences pre-ART on cytokine and neurodegenerative biomarkers CSF levels. We identified four ART-related change subgroups: (1) decline-only (learning, memory, fluency, processing speed, and attention measures), (2) mixed (improvements in learning and memory but declines in attention and executive function measures), (3) no-change, or (4) improvement-only (learning, memory, and attention measures). ART-related NP outcomes that are most likely to change included learning, memory, and attention. Motor function measures were unchanged. Subgroups differed on eight of 34 pre-ART biomarker levels including interleukin (IL)-1β, IL-6, IL-13, interferon-γ, macrophage inflammatory protein-1β, matrix metalloproteinase (MMP)-3, MMP-10, and platelet-derived growth factor-AA. The improvement-only and mixed subgroups showed lower levels on these markers versus the no-change subgroup. These findings provide support for the need to disentangle heterogeneity in ART-related neurocognitive changes, to focus on higher-order cognitive processes (learning, memory, attention) as they were most malleable to change, and to better understand why motor function remained unchanged despite ART treatment. Group differences in pre-ART CSF levels provide preliminary evidence of biological plausibility of neurocognitive phenotyping.

Machine Learning Approaches to Understand Cognitive Phenotypes in People With HIV

Cognitive disorders are prevalent in people with HIV (PWH) despite antiretroviral therapy. Given the heterogeneity of cognitive disorders in PWH in the current era and evidence that these disorders have different etiologies and risk factors, scientific rationale is growing for using data-driven models to identify biologically defined subtypes (biotypes) of these disorders. Here, we discuss the state of science using machine learning to understand cognitive phenotypes in PWH and their associated comorbidities, biological mechanisms, and risk factors. We also discuss methods, example applications, challenges, and what will be required from the field to successfully incorporate machine learning in research on cognitive disorders in PWH. These topics were discussed at the National Institute of Mental Health meeting on "Biotypes of CNS Complications in People Living with HIV" held in October 2021. These ongoing research initiatives seek to explain the heterogeneity of cognitive phenotypes in PWH and their associated biological mechanisms to facilitate clinical management and tailored interventions.

Tumor-derived extracellular vesicles modulate innate immune responses to affect tumor progression

Immune cells are capable of influencing tumor progression in the tumor microenvironment (TME). Meanwhile, one mechanism by which tumor modulate immune cells function is through extracellular vesicles (EVs), which are cell-derived extracellular membrane vesicles. EVs can act as mediators of intercellular communication and can deliver nucleic acids, proteins, lipids, and other signaling molecules between cells. In recent years, studies have found that EVs play a crucial role in the communication between tumor cells and immune cells. Innate immunity is the first-line response of the immune system against tumor progression. Therefore, tumor cell-derived EVs (TDEVs) which modulate the functional change of innate immune cells serve important functions in the context of tumor progression. Emerging evidence has shown that TDEVs dually enhance or suppress innate immunity through various pathways. This review aims to summarize the influence of TDEVs on macrophages, dendritic cells, neutrophils, and natural killer cells. We also summarize their further effects on the progression of tumors, which may provide new ideas for developing novel tumor therapies targeting EVs.

First Organoid Intelligence (OI) workshop to form an OI community

The brain is arguably the most powerful computation system known. It is extremely efficient in processing large amounts of information and can discern signals from noise, adapt, and filter faulty information all while running on only 20 watts of power. The human brain's processing efficiency, progressive learning, and plasticity are unmatched by any computer system. Recent advances in stem cell technology have elevated the field of cell culture to higher levels of complexity, such as the development of three-dimensional (3D) brain organoids that recapitulate human brain functionality better than traditional monolayer cell systems. Organoid Intelligence (OI) aims to harness the innate biological capabilities of brain organoids for biocomputing and synthetic intelligence by interfacing them with computer technology. With the latest strides in stem cell technology, bioengineering, and machine learning, we can explore the ability of brain organoids to compute, and store given information (input), execute a task (output), and study how this affects the structural and functional connections in the organoids themselves. Furthermore, understanding how learning generates and changes patterns of connectivity in organoids can shed light on the early stages of cognition in the human brain. Investigating and understanding these concepts is an enormous, multidisciplinary endeavor that necessitates the engagement of both the scientific community and the public. Thus, on Feb 22-24 of 2022, the Johns Hopkins University held the first Organoid Intelligence Workshop to form an OI Community and to lay out the groundwork for the establishment of OI as a new scientific discipline. The potential of OI to revolutionize computing, neurological research, and drug development was discussed, along with a vision and roadmap for its development over the coming decade.

Associations between Antiretrovirals and Cognitive Function in Women with HIV

Cognitive complications persist in antiretroviral therapy(ART)-treated people with HIV. However, the pattern and severity of domain-specific cognitive performance is variable and may be exacerbated by ART-mediated neurotoxicity. 929 women with HIV(WWH) from the Women's Interagency HIV Study who were classified into subgroups based on sociodemographic and longitudinal behavioral and clinical data using semi-parametric latent class trajectory modelling. Five subgroups were comprised of: 1) well-controlled HIV with vascular comorbidities(n = 116); 2) profound HIV legacy effects(CD4 nadir <250 cells/μL; n = 275); 3) primarily <45 year olds with hepatitis C(n = 165); 4) primarily 35-55 year olds(n = 244), and 5) poorly-controlled HIV/substance use(n = 129). Within each subgroup, we fitted a constrained continuation ratio model via penalized maximum likelihood to examine adjusted associations between recent ART agents and cognition. Most drugs were not associated with cognition. However, among the few drugs, non-nucleoside reverse transcriptase inhibitor (NNRTIs) and protease inhibitors(PIs) were most commonly associated with cognition, followed by nucleoside reverse transcriptase inhibitors(NRTIs) and integrase inhibitors(IIs). Directionality of ART-cognition associations varied by subgroup. Better psychomotor speed and fluency were associated with ART for women with well-controlled HIV with vascular comorbidities. This pattern contrasts women with profound HIV legacy effects for whom poorer executive function and fluency were associated with ART. Motor function was associated with ART for younger WWH and primarily 35-55 year olds. Memory was associated with ART only for women with poorly-controlled HIV/substance abuse. Findings demonstrate interindividual variability in ART-cognition associations among WWH and highlight the importance of considering sociodemographic, clinical, and behavioral factors as an underlying contributors to cognition. Are antiretroviral agents a risk factor for cognitive complications in women with HIV? We examind associations between ART-agents and cognitive function among similar subgroups of women with HIV from the Women's Interagency HIV study. The patterns of associations depended on sociodemographic, clinical, and behavioral characteristics of women.

Associations between Antiretroviral Drugs on Depressive Symptomatology in Homogenous Subgroups of Women with HIV

Antiretroviral therapy (ART) is inconsistently associated with depression. These associations may depend on factors such as biological sex, age, and health status. Identifying such factors may help optimize treatment of HIV and depression. We implemented a novel approach to examine interindividual variability in the association between ART agents and depressive symptoms. 3434 women living with HIV (WLWH) from the Women's Interagency HIV Study (WIHS) were computationally divided into subgroups based on sociodemographic (e.g., age) and longitudinal (from 1995 to 2016) behavioral and clinical profiles (e.g., substance use, HIV RNA, CD4 counts). Five subgroups (n's ranged from 482 to 802) were identified and characterized as those with: controlled HIV/vascular comorbidities; profound HIV legacy effects; younger women [<45 years of age] with hepatitis C; primarily 35-55 year olds; and poorly controlled HIV/substance use. Within each subgroup, we examined associations between ART agents used over the past 6 months and item-level depressive symptoms on the Center for Epidemiologic Studies Depression Scale. Tenofovir (4 of 5 subgroups) followed by efavirenz, emtricitabine, stavudine, lopinavir, etravirine, nelfinavir, ritonavir, and maraviroc were the most common agents associated with depressive symptoms, although the pattern and directionality varied by subgroup. For example, lopinavir was associated with fewer symptoms among the subgroup with a legacy HIV effect but more symptoms among the subgroup with well-controlled HIV/vascular comorbidities. Unexpectedly, dolutegravir and raltegravir were not associated with depressive symptoms among any subgroup. Findings underscore marked interindividual variability in ART agents on depression in WLWH. Sociodemographic, clinical, and behavioral factors are important determinants of the relationship between ART agents and depressive symptoms in WLWH. Graphical Abstract Are antiretroviral agents a risk factor for depressive symptoms in women with HIV? We examined associations between ART-agents and depressive symptoms among similar subgroups of women with HIV from the Women's Interagency HIV Study. The patterns of associations depended on sociodemographic, clinical, and behavioral characteristics of women.

Integrase Strand Transfer Inhibitor Start or Switch Impacts Learning in Women With HIV

BACKGROUND

Integrase strand transfer inhibitors (INSTIs) are first-line regimens for HIV treatment. We aimed to examine their impact on cognitive performance and depressive symptoms in women with HIV (WWH).

SETTING

Women's Interagency HIV Study, a multisite, prospective, cohort study.

METHODS

WWH who started or switched to INSTI-based antiretroviral therapy (ART) and completed neuropsychological testing and the Center for Epidemiological Studies-Depression (CES-D) scale before and after INSTI start/switch were included in the analyses. Primary outcomes were demographically corrected cognitive domain T-scores. Linear mixed-effects models adjusted for relevant covariates were used to examine effects of start/switch of any INSTI and individual INSTI drugs on cognition and CES-D scores.

RESULTS

Six hundred thirty-nine WWH, median age 49 (interquartile range 12) years, 66% Black non-Hispanic, had neuropsychological and CES-D scale data before and after INSTI start/switch. Although 14% started INSTI-based ART, the remainder switched to INSTI-based ART from another regimen. Overall, any INSTI use was associated with poorer learning post-INSTI. Specifically, use of dolutegravir and elvitegravir, but not raltegravir, was associated with poorer learning. In analyses restricted to INSTI switch, any INSTI use, and dolutegravir use, was associated with poorer learning. Among those switching from a PI-based regimen, INSTIs overall and dolutegravir remained associated with poorer learning; switching from a nonnucleoside reverse transcriptase inhibitor to dolutegravir was also associated with poorer learning. INSTI start/switch was not related to depressive symptom changes.

CONCLUSIONS

INSTI use was associated with poorer learning among WWH. These changes were mainly observed in elvitegravir and dolutegravir users, indicating that the impact of INSTI on cognition in WWH may not be a class effect.

Early Inflammatory Signatures Predict Subsequent Cognition in Long-Term Virally Suppressed Women With HIV

Immunologic function is an important determinant of cognition. Here we examined the contribution of early immune signatures to cognitive performance among HIV-infected, virally suppressed women (HIV+VS) and in HIV-uninfected (HIV-) women. Specifically, we measured serum inflammatory markers, developed combinatory immune signatures, and evaluated their associations with cognition. Forty-nine HIV+VS women in the Women’s Interagency HIV Study (WIHS) who achieved viral suppression shortly after effective antiretroviral therapy (ART) initiation, and 56 matched HIV− women were selected. Forty-two serum inflammatory markers were measured within 2 years of effective ART initiation for HIV+VS women, and at an initial timepoint for HIV− women. The same inflammatory markers were also measured approximately 1, 7, and 12 years later for all women. Of the 105 women with complete immune data, 83 (34 HIV+VS, 49 HIV−) also had cognitive data available 12 years later at ≥1 time points (median = 3.1). We searched for combinatory immune signatures by adapting a dynamic matrix factorization analytic method that builds upon Tucker decomposition followed by Ingenuity^® Pathway Analysis to facilitate data interpretation. Seven combinatory immune signatures emerged based on the Frobenius residual. Three signatures were common between HIV+VS and HIV− women, while four signatures were unique. These inflammatory signatures predicted subsequent cognitive performance in both groups using mixed-effects modeling, but more domain-specific associations were significant in HIV+VS than HIV− women. Leukocyte influx into brain was a major contributor to cognitive function in HIV+VS women, while T cell exhaustion, inflammatory response indicative of depressive/psychiatric disorders, microglial activity, and cytokine signaling predicted both global and domain-specific performance for HIV− women. Our findings suggest that immune signatures may be useful diagnostic, prognostic, and immunotherapeutic targets predictive of subsequent cognitive performance. Importantly, they also provide insight into common and distinct inflammatory mechanisms underlying cognition in HIV− and HIV+VS women.

Starting or Switching to an Integrase Inhibitor-Based Regimen Affects PTSD Symptoms in Women with HIV

As the use of Integrase inhibitor (INSTI)-class antiretroviral medications becomes more common to maintain long-term viral suppression, early reports suggest the potential for CNS side-effects when starting or switching to an INSTI-based regimen. In a population already at higher risk for developing mood and anxiety disorders, these drugs may have significant effects on PTSD scale symptom scores, particularly in women with HIV (WWH). A total of 551 participants were included after completing ≥ 1 WIHS study visits before and after starting/switching to an INSTI-based ART regimen. Of these, 14% were ART naïve, the remainder switched from primarily a protease inhibitor (PI) or non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimen. Using multivariable linear mixed effects models, we compared PTSD Civilian Checklist subscale scores before and after a "start/switch" to dolutegravir (DTG), raltegravir (RAL), or elvitegravir (EVG). Start/switch to EVG improved re-experiencing subscale symptoms (P's < 0.05). Switching to EVG improved symptoms of avoidance (P = 0.01). Starting RAL improved arousal subscale symptoms (P = 0.03); however, switching to RAL worsened re-experiencing subscale symptoms (P < 0.005). Starting DTG worsened avoidance subscale symptoms (P = 0.03), whereas switching to DTG did not change subscale or overall PTSD symptoms (P's > 0.08). In WWH, an EVG-based ART regimen is associated with improved PTSD symptoms, in both treatment naïve patients and those switching from other ART. While a RAL-based regimen was associated with better PTSD symptoms than in treatment naïve patients, switching onto a RAL-based regimen was associated with worse PTSD symptoms. DTG-based regimens either did not affect, or worsened symptoms, in both naïve and switch patients. Further studies are needed to determine mechanisms underlying differential effects of EVG, RAL and DTG on stress symptoms in WWH.

Pilot imaging of the colony stimulating factor 1 receptor in the brains of virally-suppressed individuals with HIV

OBJECTIVE

Neuroimmune activation is a putative driver of cognitive impairment in people with HIV (PWH), even in the age of modern antiretroviral therapy. Nevertheless, imaging of the microglial marker, the 18 kDa translocator protein (TSPO), with positron emission tomography (PET) in treated PWH has yielded inconclusive findings. One potential reason for the varied TSPO results is a lack of cell-type specificity of the TSPO target.

DESIGN

[ 11 C]CPPC, 5-cyano- N -(4-(4-[ 11 C]methylpiperazin-1-yl)-2-(piperidin-1-yl)phenyl) furan-2-carboxaminde, is a radiotracer for use with PET to image the colony stimulating factor 1 receptor (CSF1R). The CSF1R is expressed on microglia and central nervous system macrophages, with little expression on other cell types. We used [ 11 C]CPPC PET in virally-suppressed- (VS)-PWH and HIV-uninfected individuals to estimate the effect sizes of higher CSF1R in the brains of VS-PWH.

METHODS

Sixteen VS-PWH and 15 HIV-uninfected individuals completed [ 11 C]CPPC PET. [ 11 C]CPPC binding (V T ) in nine regions was estimated using a one-tissue compartmental model with a metabolite-corrected arterial input function, and compared between groups.

RESULTS

Regional [ 11 C]CPPC V T did not significantly differ between groups after age- and sex- adjustment [unstandardized beta coefficient ( B ) = 1.84, standard error (SE) = 1.18, P  = 0.13]. The effect size was moderate [Cohen's d  = 0.56, 95% confidence interval (CI) -0.16, 1.28), with strongest trend of higher V T in VS-PWH in striatum and parietal cortex (each P  = 0.04; Cohen's d  = 0.71 and 0.72, respectively).

CONCLUSIONS

A group difference in [ 11 C]CPPC V T was not observed between VS-PWH and HIV-uninfected individuals in this pilot, although the observed effect sizes suggest the study was underpowered to detect regional group differences in binding.

Dietary intake is associated with neuropsychological impairment in women with HIV

BACKGROUND

Diet is a modifiable risk factor that may influence cognition in people with HIV.

OBJECTIVES

We examined the association between dietary intake and cognition in women with HIV (WWH) and HIV-seronegative women.

METHODS

An 18-item dietary National Cancer Institute screener was completed by 729 WWH and 346 HIV-seronegative Women's Interagency HIV Study participants. Daily intake frequencies of processed meats, sweet beverages, fish, whole milk, and vegetables were calculated. Participants completed biennial neuropsychological (NP) testing. NP domains included attention/working memory, executive function, processing speed, memory, learning, fluency, and motor function. NP impairment was defined as demographically adjusted T-scores (mean = 50; SD = 10) ≤40 at ≥1 visit after completing the dietary screener. Multivariable logistic regression, stratified by HIV serostatus, examined associations between intake frequency tertile (referent = lowest intake) and NP performance.

RESULTS

Dietary intake frequencies of individual food line items were similar between WWH and HIV-seronegative women, except for sweet beverages, for which HIV-seronegative women reported higher intake frequencies than WWH (P values < 0.05). In WWH, multivariable-adjusted models indicated higher odds of NP impairment with higher intake frequencies of processed meat [P = 0.006; ORupper tertile = 1.91 (95% CI: 1.23-2.95; P = 0.003); ORmiddle tertile = 1.66 (95% CI: 1.14-2.42; P = 0.01)], sweet beverages [P = 0.02; ORupper tertile = 1.75 (95% CI: 1.17-2.64; P = 0.007)], fish [P = 0.01; ORupper tertile = 1.70 (95% CI: 1.10-2.64; P = 0.02)], and whole milk [P = 0.029; ORupper tertile = 1.66 (95% CI: 1.14-2.42; P = 0.008)]. Lower odds of NP impairment [P = 0.005; ORupper tertile = 0.65 (95% CI: 0.45-0.95; P = 0.02); ORmiddle tertile = 0.42 (95% CI: 0.24-0.73; P = 0.002)] were associated with higher vegetable intakes. In HIV-seronegative women, multivariable-adjusted models did not show associations between food line items/diet quality score and NP outcomes.

CONCLUSIONS

Intakes of processed meat, sweet beverages, whole milk, fish, and vegetables may be associated with NP functions among WWH. Associations among WWH are not directly comparable to those among HIV-seronegative women, because models were conducted on each group separately given controls for HIV-specific covariates in WWH. Further studies are needed using more rigorous dietary assessment methods and lengthier longitudinal follow-ups.

Brain N -acetyl-aspartyl-glutamate is associated with cognitive function in older virally suppressed people with HIV

OBJECTIVES

Cognitive impairment persists in virally suppressed people with HIV (VS-PWH) especially in higher order domains. One cortical circuit, linked to these domains, is regulated by N -acetyl-aspartyl glutamate (NAAG), the endogenous agonist of the metabotropic glutamate receptor 3. The enzyme glutamate carboxypeptidase II (GCPII) catabolizes NAAG and is upregulated in aging and disease. Inhibition of GCPII increases brain NAAG and improves learning and memory in rodent and primate models.

DESIGN

As higher order cognitive impairment is present in VS-PWH, and NAAG has not been investigated in earlier magnetic resonance spectroscopy studies (MRS), we investigated if brain NAAG levels measured by MRS were associated with cognitive function.

METHODS

We conducted a retrospective analysis of 7-Tesla MRS data from a previously published study on cognition in older VS-PWH. The original study did not separately quantify NAAG, therefore, work for this report focused on relationships between regional NAAG levels in frontal white matter (FWM), left hippocampus, left basal ganglia and domain-specific cognitive performance in 40 VS-PWH after adjusting for confounds. Participants were older than 50 years, negative for affective and neurologic disorders, and had no prior 3-month psychoactive-substance use.

RESULTS

Higher NAAG levels in FWM were associated with better attention/working memory. Higher left basal ganglia NAAG related to better verbal fluency. There was a positive relationship between hippocampal NAAG and executive function which lost significance after correction for confounds.

CONCLUSION

These data suggest brain NAAG serves as a biomarker of cognition in VS-PWH. Pharmacological modulation of brain NAAG warrants investigation as a therapeutic approach for cognitive deficits in VS-PWH.

Altered development and network connectivity in a human neuronal model of 15q11.2 deletion-related neurodevelopmental disorders

The chromosome 15q11.2 locus is deleted in 1.5% of patients with genetic epilepsy and confers a risk for intellectual disability and schizophrenia. Individuals with this deletion demonstrate increased cortical thickness, decreased cortical surface area and white matter abnormalities. Human induced pluripotent stem cell (iPSC)-derived neural progenitor cells (NPC) from 15q11.2 deletion individuals exhibit early adhesion junction and migration abnormalities, but later neuronal development and function have not been fully assessed. Imaging studies indicating altered structure and network connectivity in the anterior brain regions and the cingulum suggest that in addition to alterations in progenitor dynamics, there may also be structural and functional changes within discrete networks of mature neurons. To explore this, we generated human forebrain cortical neurons from iPSCs derived from individuals with or without 15q11.2 deletion and used longitudinal imaging and multielectrode array analysis to evaluate neuronal development over time. 15q11.2 deleted neurons exhibited fewer connections and an increase in inhibitory neurons. Individual neurons had decreased neurite complexity and overall decreased neurite length. These structural changes were associated with a reduction in multiunit action potential generation, bursting and synchronization. The 15q11.2 deleted neurons also demonstrated specific functional deficits in glutamate and GABA mediated network activity and synchronization with a delay in the maturation of the inhibitory response to GABA. These data indicate that deletion of the 15q11.2 region is sufficient to impair the structural and functional maturation of cortical neuron networks which likely underlies the pathologic changes in humans with the 15q11.2 deletion.

Integrase Inhibitors are Associated with Neuropsychiatric Symptoms in Women with HIV

OBJECTIVE

Women with HIV(WWH) are more likely to discontinue/change antiretroviral therapy(ART) due to side effects including neuropsychiatric symptoms. Efavirenz and integrase strand transfer inhibitors(INSTIs) are particularly concerning. We focused on these ART agents and neuropsychiatric symptoms in previously developed subgroups of WWH that differed on key sociodemographic factors as well as longitudinal behavioral and clinical profiles. WWH from the Women's Interagency HIV Study were included if they had ART data available, completed the Perceived Stress Scale-10 and PTSD Checklist-Civilian. Questionnaires were completed biannually beginning in 2008 through 2016. To examine ART-symptom associations, constrained continuation ratio model via penalized maximum likelihood were fit within 5 subgroups of WWH. Data from 1882 WWH contributed a total of 4598 observations. 353 women were previously defined as primarily having well-controlled HIV with vascular comorbidities, 463 with legacy effects(CD4 nadir < 250cells/mL), 274 aged ≤ 45 with hepatitis, 453 between 35-55 years, and 339 with poorly-controlled HIV/substance users. INSTIs, but not efavirenz, were associated with symptoms among key subgroups of WWH. Among those with HIV legacy effects, dolutegravir and elvitegravir were associated with greater stress/anxiety and avoidance symptoms(P's < 0.01); dolutegravir was also associated with greater re-experiencing symptoms(P = 0.005). Elvitegravir related to greater re-experiencing and hyperarousal among women with well-controlled HIV with vascular comorbidities(P's < 0.022). Raltegravir was associated with less hyperarousal, but only among women aged ≤ 45 years(P = 0.001). The adverse neuropsychiatric effects of INSTIs do not appear to be consistent across all WWH. Key characteristics (e.g., age, hepatitis positivity) may need consideration to fully weight the risk-benefit ratio of dolutegravir and elvitegravir in WWH.

Trauma Across the Life Span and Multisystem Morbidity in Women With HIV

OBJECTIVE

Sexual and physical abuse are highly prevalent among women living with HIV (WLWH) and are risk factors for the development of mental health and substance use disorders (MHDs, SUDs), and cognitive and medical comorbidities. We examined empirically derived patterns of trauma, MHD, and SUD, and associations with later cognitive and health outcomes.

METHODS

A total of 1027 WLWH (average age = 48.6 years) in the Women's Interagency HIV Study completed the World Mental Health Composite International Diagnostic Interview from 2010 to 2013 to identify MHDs, SUDs, and age at onset of sexual and physical abuse. Then, cognitive impairment, cardiovascular/metabolic conditions, and HIV disease outcomes were assessed for up to 8.8 years. Latent class analysis identified patterns of co-occurring trauma, MHDs, and/or SUDs. Generalized estimating equations determined associations between these patterns and midlife cognitive and medical outcomes.

RESULTS

Six distinct profiles emerged: no/negligible sexual/physical trauma, MHD, or SUD (39%); preadolescent/adolescent sexual trauma with anxiety and SUD (22%); SUD only (16%); MHD + SUD only (12%); early childhood sexual/physical trauma only (6%); and early childhood sexual/physical trauma with later MHD + SUD (4%). Profiles including early childhood trauma had the largest number of midlife conditions (i.e., cognitive, cardiovascular, HIV-related). Preadolescent/adolescent sexual trauma with anxiety and SUD predicted both global and domain-specific cognitive declines. Only SUD without trauma predicted lower CD4, whereas childhood trauma with MHD + SUD predicted increased CD8.

CONCLUSIONS

WLWH have complex multisystem profiles of abuse, MHD, and/or SUD that predict midlife cognitive, metabolic/cardiovascular, and HIV outcomes. Understanding the interplay between these factors over time can identify risks and personalize preventative and treatment interventions.

Tryptophan-Kynurenine Pathway Activation and Cognition in Virally Suppressed Women With HIV

BACKGROUND

Immune and cognitive dysfunction persists even in virally suppressed women with HIV (VS-WWH). Since inflammation and HIV proteins induce the enzyme indoleamine 2,3-dioxygenase (IDO), converting tryptophan (T) to kynurenine (K) while producing downstream neurotoxic metabolites, we investigated IDO activation (KT ratio) in relation to cognition in VS-WWH and demographically similar women without HIV (WWoH).

METHODS

Ninety-nine VS-WWH on stable antiretroviral therapy and 102 WWoH (median age 52 vs 54 years; 73% vs 74% Black, respectively) from the New York and Chicago sites of the Women's Interagency HIV Study (WIHS) completed a neuropsychological test battery assessing motor function, processing speed, attention/working memory, verbal fluency, verbal learning and memory, and executive function and had plasma measured for tryptophan-kynurenine metabolites through liquid chromatography-tandem mass spectrometry and monocyte-derived [soluble cluster of differentiation-14 (sCD14), soluble cluster of differentiation-163 (sCD163), monocyte chemoattractant protein-1 (MCP-1)] plus general inflammatory markers [tumor necrosis factor alpha-2 receptor (TNF-R2), high-sensitivity C-reactive protein, high-sensitivity interleukin-6] through enzyme-linked immunosorbent assays between 2017 and 2020.

RESULTS

VS-WWH had a higher KT ratio (P < 0.01) and higher sCD14 levels (P < 0.05) compared with WWoH. Higher sCD163 was associated with higher KT ratio (R = 0.29, P < 0.01) and worse fine motor function in VS-WWH; after adjusting for sCD163 and sCD14 in multivariable regressions, higher KT ratio remained significantly associated with impaired fine motor function in VS-WWH only (standardized β = -0.29, P < 0.05). IDO activation was not associated with cognition in WWoH.

CONCLUSIONS

IDO activation (K:T) was associated with worse fine motor control in VS-WWH independent of measured systemic inflammation. Further studies investigating biological mechanisms linking IDO activation to fine motor function among VS-WWH are warranted.

Development of a refined harmonization approach for longitudinal cognitive data in people with HIV

OBJECTIVES

The aim of this study was to develop a refined method for harmonizing longitudinal cognitive data across several large-scale studies in people with HIV (PWH), in whom cognitive complications are common and heterogeneous in presentation.

STUDY DESIGN AND SETTING

We developed a refined method for harmonizing longitudinal cognitive data across five large-scale studies in PWH that used different cognitive batteries with only some overlapping tests-Women's Interagency HIV Study (WIHS), Multicenter AIDS Cohort Study, CNS HIV Antiretroviral Therapy Effects Research (CHARTER), National NeuroAIDS Tissue Consortium, and the HIV Neurobehavioral Research Program. Traditional data harmonization methods using latent variable models focus on cross-sectional data and require the presence of common cognitive tests to serve as "linking" assessments. However, the absence of such common tests for certain cognitive domains can preclude the direct application of these traditional techniques. To address these challenges, we developed a harmonization method that leveraged a second-order factor model, which capitalized on the structural relationships among cognitive domains.

RESULTS

Our approach yielded harmonized cognitive domain scores that are demographically consistent across different cohorts and exhibit strong correlations with the raw or log transformed (eg, timed outcomes) cognitive test scores. These harmonized scores accurately reflected variations according to age, educational status, and other demographic factors, while preserving participants' longitudinal cognitive trajectories.

CONCLUSION

Our harmonization methods are essential for future analyses of large-scale, retrospective data to understand the heterogeneity in cognitive complications in PWH. These methods can be applied to harmonize new datasets with similar measures.