Drexel University

NIH Research Projects · FY 2025 · 2023-09

Project Abstract Pancreatic ductal adenocarcinoma (PDAC) is a deadly disease with a dismal survival rate at just 10%, largely because most patients are diagnosed after the cancer has spread beyond the pancreas. PDAC is thought to arise from two types of noninvasive precancerous lesions, namely, pancreatic intraepithelial neoplasia (PanINs), and intraductal papillary mucinous neoplasms (IPMN), that develop in the ductal epithelium of the pancreas. Here, IPMNs are large cystic neoplasms that are incidentally detected at increasing frequencies through abdominal imaging. Comprehensive genomic analyses indicate that activating mutations in KRAS, GNAS, and PI3KCA are associated with IPMN pathogenesis. Although genetically engineered mouse models (GEMMs) have provided some insights into the development of IPMN, how IPMNs arise in humans in the context of mutations that are exclusively found in IPMN lesions (GNAS and PIK3CA) and what cooperating events promote progression to carcinoma is not understood. To address this question, we have developed a robust platform to generate ductal and acini organoids from human embryonic stem cell (hESC)-derived pancreatic progenitor cells. Using human exocrine pancreas, I have found that expression of GNASR201C in human ductal organoids recapitulates several features of IPMN including lumen expansion, and secretion of mucins such as MUC2. This study sets out to test the hypothesis that oncogenic GNAS promotes cell proliferation through PKA-independent mechanisms in ductal cells and cooperates with other genetic events to promote initiation and progression of IPMN lesions in vivo. Using a combination of cell biology, proteomics, and orthotopic transplantation approaches, this proposal aims to identify mechanisms through which oncogenic GNAS differentially regulates cell proliferation in ductal and acini pancreatic organoids (Aim1); and explore additional genetic events through which oncogenic GNAS promotes formation of IPMN and IPMN-derived PDAC in the context of a physiologically accurate tissue environment (Aim 2 and 3). The expected results will provide insights into the cell of origin for IPMN lesions; identify mechanisms by which GNAS promotes early lesions; and establish models of IPMN- derived PDAC, which may be exploited therapeutically in the long term to treat a broad range of IPMN-associated tumors. The K22 award will allow participation in laboratory management, mentorship and grant writing workshops, and enrolment in didactic courses, that will provide me with the necessary knowledge, resources and training to (a) understand principles of omics research; (b) model cancer in mice; and (c) apply for additional funding (R01) opportunities. Together with the support of my collaborators and establishment of an advisory committee after obtaining a faculty position, my overall research, training and career development will help me establish a unique niche in pancreatic cancer research as an independent investigator.

NIH Research Projects · FY 2025 · 2023-09

Project Summary The majority of alcohol users in the US consume alcohol at doses and frequencies that are not consistent with alcohol use disorder (AUD). There is growing evidence that low-dose ethanol exposure impacts the brain and behavior but despite this, the behavioral and neurobiological consequences of chronic low-dose alcohol consumption are poorly understood. The decision to seek a reward has a direct relationship with its value. The ability to reassess and update reward value is critical for adaptive value-guided decision making. Deficits in the processes that moderate motivated behavior may contribute to the transition from casual alcohol consumption to AUD. Data from our lab indicate that chronic low-dose ethanol enhances reward motivation in a progressive ratio (PR) task in male, but not female, mice. In contrast, ethanol-exposed female mice are more sensitive to reduced reward value than ethanol-naïve females, whereas ethanol exposure did not increase sensitivity to change in reward value in males. These changes may result from an ethanol-induced dysregulation in the ability to use reward value information to guide behavior, which can be determined experimentally through the use of a value-guided decision making task. One potential neurobiological substrate mediating this effect is the basolateral amygdala (BLA). The BLA is a key neuroanatomical substrate of reward value encoding and participates in updating value information and influencing value-guided decision making. Preliminary data from our lab suggest that chronic low-dose ethanol exposure decreases cFos expression in BLA and its projections to the nucleus accumbens (NAc) following reward seeking. This proposal will test the overarching hypothesis that chronic-low-dose ethanol alters BLA glutamate receptor expression, thus contributing to impairments in detecting and using reward value information to guide behavior. In Aim 1, we will use a value-guided decision- making task to test our hypothesis that chronic low-dose ethanol impairs the ability to update changes in reward value for adaptive behavior. In Aim2, we will investigate the impact of chronic low-dose ethanol exposure on BLA and NAc postsynaptic glutamate receptors and the relationship between these changes and performance on the value-guided decision-making task. Aim 3 will use chemogenetic strategies to test the hypothesis that inhibiting the BLA or BLA → NAc circuit activity will impair the ability to successfully use reward value information during a value-guided decision-making task. The results from these experiments will expand our understanding of the impacts of chronic low-dose ethanol exposure on behavior and neurobiology, which is an area that remains severely understudied in the alcohol use field. Further, this fellowship will enable the applicant to build on her expertise in learning and memory processes which may be dysregulated by alcohol use by integrating a conceptual understanding of low-dose ethanol effects on molecular substrates, specific circuits, and behavior. The abundance of resources and opportunities available in the Barker lab and at Drexel University will ensure that the applicant is prepared and qualified for an independent alcohol research career.

NIH Research Projects · FY 2024 · 2023-09

Project Summary Abstract The extreme emotional strain of parenting an infant in the fast-paced medicalized Neonatal Intensive Care Unit (NICU) setting can be detrimental to mental health and functioning with up to 70% of parents experiencing clinically significant levels of depression, anxiety and trauma symptoms. Poor parental mental health contributes to maladaptive coping and can impair parental functioning, parent-infant attachment, and long-term infant development. Therefore, early identification of and support for parents at-risk for clinical distress is of paramount importance. Clinical and research experts have recommended universal screening and ongoing mental health assessment for all NICU parents to identify specific needs and offer appropriate levels of support. Unfortunately, widespread implementation of a clinically practical approach has not been achieved. Barriers to screening include competing demands on parents’ time and focus during daytime hours, such as participating in infant care, pumping/breastfeeding, meeting with health care providers (HCPs), and making complex decisions about life-threatening medical procedures, as well as job demands and caretaking for their other children. Obstacles such as staff availability (e.g., to screen and treat during evenings and weekends) and staff burden limit service implementation to parents given the focus on medically complex infants receiving intensive care. Mobile health (mHealth) interventions offer an innovative approach to tackle these barriers. The overarching goal of the current proposal is to develop and test a novel mHealth app entitled, EmBRACE (Empower NICU – A Bridge to Resources for Adjusting and Coping with Emotions) to establish: 1. Universal mental health screening while giving NICU parents control over when and where assessments are completed; 2. Ongoing mental health monitoring using a set of quick daily assessments (via ecological momentary assessment) and weekly screenings; 3. Provision of customized microlearning education (e.g., 1-3 minute videos) tailored to assessment results and referrals in a stepped-care approach; and 4. Use of a sustainable contingency management approach to increase parent compliance with assessments, microlearning, and referral follow-up. In the R21 phase, we aim to 1) conduct formative research with NICU parents and HCPs that leverages a user-centered design and the PRECEDE-PROCEED theoretical model to develop the EmBRACE prototype; and 2) evaluate the feasibility (usability, acceptability, and clinical applicability) of EmBRACE with 20 current NICU parents. In the R33 phase, we aim to 1) revise the EmBRACE platform; and 2) conduct a multisite, pilot randomized controlled trial in NICUs located across the U.S. with 120 current NICU parents to test EmBRACE’s efficacy relative to an active comparator group. EmBRACE has the potential to reduce the significant gaps in mental health care for NICU parents by providing universal screening, ongoing monitoring, and linkage to tailored psychoeducation and referrals, thereby assisting overburdened NICU HCPs, and ultimately promoting best practices to optimize parent and infant outcomes.

NIH Research Projects · FY 2024 · 2023-08

Abstract: Lyme disease (LD) leads to lifelong health problems if standard antibiotic therapy is not initiated during the first 2-3 weeks after infection. Diagnosis for LD currently relies on seroconversion and is unreliable during acute disease. Cases of suspected acute LD should be confirmed using clinical diagnostic assays. N- linked glycosylation is one of the most abundant post-translational modifications of serum proteins. While it is dynamic in nature, it is also highly consistent in a healthy state. N-linked glycosylation of serum immunoglobulins (Igs) are known to change in a disease specific manner and can direct the host immune response toward a pro- or an anti-inflammatory response. We previously observed that Ig N-glycans produced during acute LD contain specific alterations in the abidance of galactose and sialic acid. We hypothesize that these Ig alterations are antigen-specific, and that the glycosylation patterns present will negatively impact downstream immune responses. This hypothesis is based on our preliminary data, known LD B-cell perturbations, and reports of IgG N-glycans altering the immune response to COVID-19, tuberculosis, multiple sclerosis, and HIV. This proposal is novel and unique because it is the only study that examines the role of glycosylation during the human immune response to LD. This proposal is built on our preliminary work where we identified aberrant glycosylation on the total serum IgG and IgM in acute LD patients prior to seroconversion. In this proposal, we examine the glycosylation of Igs specific to LD antigens and determine if acute LD infection will alter B-cell responses to produce antigen specific Igs with the same unique glycosylation changes seen in our preliminary data. Additionally, we examine how the glycosylation pattern on antigen specific Igs effect the immune response to LD. In Aim 1, we isolate Igs specific to the LD antigen VlsE and establish the IgG and IgM N-glycan profiles. The result will determine if antigen specific Igs contain the same aberrant glycosylation found in the total Ig population of acute LD patients. In Aim 2, we quantify the impact of LD antigen-specific IgG glycosylation on the promotion of ADCC and complement deposition. The result will determine if there is a link between IgG glycosylation and the inability of the patients to clear the Borrelia burgdorferi spirochete that causes LD. In Aim 3, we quantify the impact of antigen-specific IgM glycosylation on the complement deposition rate. Complement deposition leads to rapid clearance of Lyme disease pathogens. Altered glycosylation of IgM could impair complement deposition and impede the ability of the human host to clear the infection. This work will establish a new mechanism of Borrelial immune evasion, characterize the host-response to LD pathogenesis in humans. Additionally, the results will potentiate the use of Ig N-glycans to serve as multiplexed biomarkers in a novel Lyme disease diagnostic assay and guide the glycoengineering of antibodies for use in intravenous therapy in hard-to-treat disseminated Lyme disease cases.

NIH Research Projects · FY 2025 · 2023-07

PROJECT SUMMARY Liver disease mortality is a key contributor to recent declines in life expectancy in the US. Decades of research have demonstrated the disproportionate burden of liver disease among racial/ethnic minorities and those with low-socioeconomic position. With the ongoing epidemic of obesity, and the increase in alcohol consumption, fatty liver diseases (FLD), including non-alcoholic fatty liver disease (NAFLD) and alcohol-related liver disease (ALD), have become the most prevalent chronic liver conditions affecting millions of people worldwide, constituting a major and growing public health problem. FLD epidemiology has largely focused on the role of individual-level behavioral factors, such as obesity and alcohol consumption, in FLD development. However, individual-focused therapeutic and preventive efforts have had limited success. For many chronic diseases, abundant literature has documented how social and physical environments pattern population health. In contrast, the empirical evidence of the role of social determinants of health with FLD and its disparities is extremely limited. Furthermore, the current paradigm to explain FLD disparities is heavily focused on genetic susceptibility (e.g. PNPLA3 gene variants). To address these research gaps, this project will test the novel hypothesis that individual and community- level social determinants influence FLD risk and their social and racial/ethnic disparities. To test this hypothesis, we propose to obtain and analyze longitudinal measures of liver fat and inflammation among participants of the Multi-Ethnic Study of Atherosclerosis (MESA), the largest ongoing multi-racial population-based cohort study involving 6,814 men and women (22% Hispanic, 38% whites, 28% Blacks, 12% Chinese) from 6 geographically distinct areas of the US. MESA has the most comprehensive longitudinal data on socioeconomic (both individual and community level), psychosocial, neighborhood physical and social environment, environmental, behavioral, and biomedical (including genetics) factors and health outcomes with up to 21 years of follow up. Our specific aims are: 1) Characterize racial/ethnic disparities in FLD incidence, as measured by 10-year changes in CT- measured liver fat and liver enzymes, while accounting for genetic variants. 2) Examine the prospective association of individual-level socioeconomic position (SEP) and psychosocial stressors with FLD incidence and the contribution of SEP and psychosocial factors to socioeconomic and racial/ethnic disparities in FLD incidence. 3) Examine the prospective association of community-level social and physical features with FLD incidence and its racial/ethnic disparities in FLD incidence. 4) Examine the role of community-level social and physical features in magnifying individual-level genetic vulnerability by testing gene-by-environment interactions in the incidence of FLD between genetic variants and contextual factors. This project will constitute the largest, most rigorous and comprehensive investigation of the role of social determinants of health in the development and progression of FLD and its disparities.

NIH Research Projects · FY 2025 · 2023-07

PROJECT SUMMARY The HIV-1 envelope glycoprotein spike (Env) mediates viral entry into target cells. Because Env is the only viral protein on the virion surface, it is central to the development of potential vaccines and small-molecule entry inhibitors. Env is a uniquely flexible molecular machine, and deep understanding of its immunogenicity and susceptibility to inhibition requires an appreciation of its atomically resolved conformational dynamics. Structural studies using truncated, solubilized, and stabilized Env constructs have yielded detailed atomic models of its main open and closed conformational states. Emerging structural studies of full-length Env support identification of asymmetric closed conformations as the “default intermediate state” (DIS), revealing details of a potentially pivotal role of quaternary asymmetry in Env conformational dynamics. At the same time, both single-molecule FRET (smFRET) and crosslinking mass spectrometry (XL-MS) of Env suggest the existence of at least one, sometimes dominant conformational state that has not been structurally characterized. This “State-1” conformation nonetheless seems relevant for both immune recognition and susceptibility to small-molecule inhibitors. We will leverage advanced Molecular Dynamics (MD) methods including targeted MD, temperature-accelerated MD, and string method to provide atomic level models for the opening of HIV-1 Env from closed (State 2) to open (State 3) conformational states and to identify critical structural changes separating State-2 from the poorly understood State-1 Env. The MD simulation methods we use will incorporate biases from multi-perspective smFRET and XL-MS, and they will in turn provide direction for expanding the set of Env constructs used in those experiments, establishing an iterative approach that progressively better defines transition mechanisms and State 1. An atomic-level understanding of HIV-1 Env conformational dynamics, identification of a yet to be structurally characterized pre-triggered conformational states, as well as the mechanism of Env activation for fusion will inform immunogen design and antiviral therapies.

NIH Research Projects · FY 2025 · 2023-07

Project Summary/ Abstract: The E1-E2-E3 ligase cascade is responsible for tagging substrate proteins with ubiquitin. Addition of ubiquitin then directs the tagged protein along one of several paths, including marking it for proteasome-mediated degradation. The E3 ligase is responsible for recognition of substrate proteins, and thus encodes the specificity of ubiquitin transfer. The human proteome comprises about 600 known E3 ligases, each with a distinct substrate specificity that allows it to engage a prescribed subset of the proteome. Given that one of the prototypical consequences of ubiquitination is to mark a protein for destruction, it is unsurprising that dysregulation or mutation of E3 ligases can lead to a disruption of cellular homeostatic balance: accordingly, E3 ligases have been implicated in a wide variety of diseases including autoimmune disease and cancer. Intriguingly, certain disease-associated mutations have been found to alter the substrate specificity of an E3 ligase – these mutations not only impact the cellular levels of proteins within the E3’s normal interactome, but rather they change the E3 ligase’s interactome. Similar effects have also been observed from certain small molecules, termed molecular glues, that also modify the substrate specificity of an E3 ligase: these compounds typically redirect an E3 ligase to ubiquitinate some “neo-substrate”, ultimately leading to degradation of this protein. Thus, molecular glues afford the possibility of targeting disease-causing proteins that were previously thought to be undruggable. To date, however, the transient nature of E3 ligase’s interactions with their substrates (and neo-substrates) has served as a bottleneck for identifying both endogenous and “glue-able” substrates of E3 ligases. To address this, here I propose to develop cutting-edge structure-based machine learning methods to (1) computationally identify endogenous substrates of E3 ligases, and (2) rationally design molecular glues that degrade a traditionally undruggable target protein. After carefully benchmarking the underlying methods for each task, I will apply the former to comprehensively catalog substrates of three specific disease-relevant E3 ligases. In parallel, I will apply my approach for the latter to design molecular glues intended to degrade ADAR1, a key protein that promotes resistance to immune checkpoint blockade therapy and is thus a potential target for intervention in many different cancers. Beyond the immediate scope of this proposal, I anticipate that the methods developed through these studies will help illuminate the underlying biology of many other E3 ligases, and will facilitate development of molecular glue degraders targeting key drivers in many other diseases.

NIH Research Projects · FY 2025 · 2023-07

The HIV pandemic is increasingly driven by the spread of infection in vulnerable sub-populations with a relatively high prevalence of substance abuse disorders (SUD), including the use of stimulants such as Methamphetamine (Meth) and Cocaine (Coc). Stimulant use accelerates systemic disease, and can drive changes in neuropathogenesis, increase risk neuropsychiatric comorbidities and accelerate cognitive decline, despite effective ART. Despite the high prevalence of stimulant use among PLWH, the mechanisms by which stimulants impact disease progression are poorly defined. This is particularly true in the CNS, as there are substantial technical challenges involved in modeling microglial infection and interaction with neurons, as well as the subsequent changes that this has on neuronal function. All stimulants increase CNS dopamine release, exposing myeloid populations to highly elevated dopamine levels. Data indicate that it is the exposure to released dopamine, rather than the stimulants themselves, which drives changes in microglial infection and function. Our data support this, showing stimulant induced dopamine levels increase HIV entry and enhance myeloid inflammation, increasing cytokine release, and NF-κB and NRLP3 inflammasome activity in vitro and in the NHP CNS. Neuroinflammation driven by infected CNS myeloid populations is central to HIV neuropathogenesis in the ART era, underlying the neuronal dysfunction and disruptions in neuroimmune communication that lead to cognitive impairment and behavioral changes. We hypothesize that stimulant use exacerbates HIV- associated microglial inflammation through dopamine receptor activation, leading to neuronal dysfunction in neuroHIV. To address this, we propose to develop tractable, syngeneic co-cultures of human iPSC-derived microglia (iMG) and iPSC-derived dopamine neurons (iDAN). Critically, these iDAN will release dopamine in vitro in response to stimulant exposure. Co-cultures will be based on our existing protocols for iMG and iDAN differentiation and will be developed and optimized for high-throughput analysis during the R61 phase. During the R61, we will infect with HIV and treat with stimulants +/- ART, then use high content imaging, single cell RNA-seq / ATAC-seq and Alphalisas to evaluate changes in viral dynamics (Aim 1b), gene expression and chromatin accessibility (Aim 1c) and inflammation pathways (NF-κB, AP-1, STAT and NLRP3 activity, Aim 1d). Using the R61 results as readouts, the R33 phase will use pharmacologic inhibition and CRISPR to identify the specific dopamine receptors involved in each readout (Aim 2), and to examine neuronal function and neuroimmune interaction (Aim 3) by evaluating; resting membrane potential and neuron firing rate with patch clamp electrophysiology, dendritic spine density and morphology and microglial-neuronal contacts using confocal imaging and Neurolucida360 analysis, and neuronal network activity using multielectrode arrays. This will define specific dopamine receptors and microglial or neuronal functions that can be targeted to ameliorate the impact of SUD on inflammation in PLWH by manipulating dopaminergic activity.

NIH Research Projects · FY 2024 · 2023-07

The HIV pandemic is increasingly driven by the spread of infection in vulnerable sub-populations with a relatively high prevalence of substance abuse disorders (SUD), including the use of stimulants such as Methamphetamine (Meth) and Cocaine (Coc). Stimulant use accelerates systemic disease, and can drive changes in neuropathogenesis, increase risk neuropsychiatric comorbidities and accelerate cognitive decline, despite effective ART. Despite the high prevalence of stimulant use among PLWH, the mechanisms by which stimulants impact disease progression are poorly defined. This is particularly true in the CNS, as there are substantial technical challenges involved in modeling microglial infection and interaction with neurons, as well as the subsequent changes that this has on neuronal function. All stimulants increase CNS dopamine release, exposing myeloid populations to highly elevated dopamine levels. Data indicate that it is the exposure to released dopamine, rather than the stimulants themselves, which drives changes in microglial infection and function. Our data support this, showing stimulant induced dopamine levels increase HIV entry and enhance myeloid inflammation, increasing cytokine release, and NF-κB and NRLP3 inflammasome activity in vitro and in the NHP CNS. Neuroinflammation driven by infected CNS myeloid populations is central to HIV neuropathogenesis in the ART era, underlying the neuronal dysfunction and disruptions in neuroimmune communication that lead to cognitive impairment and behavioral changes. We hypothesize that stimulant use exacerbates HIV- associated microglial inflammation through dopamine receptor activation, leading to neuronal dysfunction in neuroHIV. To address this, we propose to develop tractable, syngeneic co-cultures of human iPSC-derived microglia (iMG) and iPSC-derived dopamine neurons (iDAN). Critically, these iDAN will release dopamine in vitro in response to stimulant exposure. Co-cultures will be based on our existing protocols for iMG and iDAN differentiation and will be developed and optimized for high-throughput analysis during the R61 phase. During the R61, we will infect with HIV and treat with stimulants +/- ART, then use high content imaging, single cell RNA-seq / ATAC-seq and Alphalisas to evaluate changes in viral dynamics (Aim 1b), gene expression and chromatin accessibility (Aim 1c) and inflammation pathways (NF-κB, AP-1, STAT and NLRP3 activity, Aim 1d). Using the R61 results as readouts, the R33 phase will use pharmacologic inhibition and CRISPR to identify the specific dopamine receptors involved in each readout (Aim 2), and to examine neuronal function and neuroimmune interaction (Aim 3) by evaluating; resting membrane potential and neuron firing rate with patch clamp electrophysiology, dendritic spine density and morphology and microglial-neuronal contacts using confocal imaging and Neurolucida360 analysis, and neuronal network activity using multielectrode arrays. This will define specific dopamine receptors and microglial or neuronal functions that can be targeted to ameliorate the impact of SUD on inflammation in PLWH by manipulating dopaminergic activity.

NIH Research Projects · FY 2024 · 2023-07

Project Summary Volumetric muscle loss (VML) is a debilitating injury caused by trauma or disease to skeletal muscle that leads to incapacitating fibrosis and loss of limb function. We and others have identified delayed clearance of apoptotic neutrophils as a primary mediator of fibrosis via detrimental effects on satellite cell and macrophage behavior. Because macrophages are critical regulators of wound healing and also the primary cell type that clear apoptotic neutrophils in a process called efferocytosis, macrophage cell therapy is a promising therapeutic approach, but is limited by two main challenges: 1) Macrophages are highly plastic cells that rapidly shift phenotype in response to microenvironmental cues. Therefore, a strategy is needed to control their phenotype in situ following administration, to prevent them from changing phenotype in response to pro-inflammatory cues at the site of injury. 2) High manufacturing costs and regulatory hurdles prevent the use of autologous (patient- derived) macrophages, especially because very high numbers are required, but allogeneic (donor-derived) macrophages elicit a strong T cell-mediated adverse immune response. We developed an innovative biomaterial-mediated macrophage cell therapy strategy that simultaneously addresses both of these challenges. In this strategy, referred to as Particle-Assisted Control over Macrophage-Neutrophil interactions (Pac-Man), the macrophages are first loaded ex vivo with polymeric biodegradable microparticles that slowly release dexamethasone intracellularly, thus controlling macrophage phenotype from the inside out following their administration to sites of injury. Dexamethasone was selected because it causes an anti-inflammatory/pro- regenerative phenotype in macrophages, increases their efferocytosis of apoptotic cells, and suppresses their ability to activate T cells. Thus, the intracellular release of dexamethasone following administration of the macrophages to sites of injury is expected to make them clear detrimental neutrophils, resolve inflammation, and suppress T cell activation to prevent rejection of allogeneic cells. In Aim 1, the functional phenotype of the adoptively transferred Pac-Man macrophages will be rigorously characterized over time in vitro and in vivo using flow cytometry, gene expression profiling, and analysis of their interactions with apoptotic neutrophils. Effects on muscle repair will be assessed using histology and functional mechanical testing. In Aim 2, the potential to use an allogeneic cell source will be tested in vitro and in vivo using primary human immune cells from mixed donors and mice from different strains. This project will advance an innovative off-the-shelf, translational cell therapy to enhance clearance of apoptotic cells, which would be transformative for the treatment of fibrotic injuries such as VML and many others.

NIH Research Projects · FY 2024 · 2023-06

PROJECT SUMMARY/ABSTRACT HIV transmission in sub-Saharan Africa (SSA) occurs predominantly among young people (aged 15-24 years old) and within micro-epidemics (high HIV prevalence areas). Among adolescents, girls account for 80% of all adolescent HIV infections (15-19 years old) and adolescent mothers (AMs) are at higher HIV risk than non-parenting girls. However, as AMs have been largely overlooked in HIV prevention research, gaps in knowledge regarding where micro-epidemics occur among AMs and how structural (e.g., urbanization) and relational HIV risk factors impact adolescent mothers’ HIV risk remain. Further, despite differences in AMs’ relationship configurations, no studies have examined how the co-occurrence of relational factors impact AMs’ vulnerability to HIV and unprotected sex using a typological approach. Moreover, most HIV studies on AMs in SSA use a single-level approach to describe HIV risk as opposed to a multilevel framework that incorporates spatial (i.e., structural factors) and non-spatial (i.e., relationship typologies, individual and familial factors) risk factors. This exploratory study will use a modified social ecological framework to identify micro-epidemics, and to characterize relationship typologies and multilevel factors that impact AMs’ HIV risk. The specific aims are to: 1) characterize HIV micro-epidemics among AMs in SSA, 2) identify typologies of AMs’ sexual relationships, and 3) assess whether multilevel factors are associated with HIV risk and unprotected sex among AMs. To address these aims, this study will use (1) secondary data from the Population-based HIV Impact Assessment (PHIA), which includes 2,879 AMs (aged 15-19 years old); and (2) publicly available structural-level data, from various sources which will be linked to PHIA cluster-level data. Multiple quantitative analytic approaches will be used to execute aims, including spatial and machine learning techniques (Aim 1), latent class analysis (Aim 2), and mixed effects modeling (Aim 3). Study findings may inform targeted HIV prevention interventions for AMs. This study aligns with the NICHD’s research priorities by examining structural risk factors of HIV in a high-risk setting and the UNAIDS 95-95-95 goal. The training plan developed by the PI, sponsor Dr. Félice Lê- Scherban, and co-sponsors Drs. Allison Groves and Alex Ezeh, supports the proposed research and the PI’s training goals, which are to: 1) gain expertise in theoretical frameworks of social epidemiological and adolescent health research, 2) develop methodological skills in machine learning and latent class analysis, and 3) refine research dissemination, communication, and scholarly writing skills. The PI will leverage resources at Drexel University Dornsife School of Public Health, a collaborative and multidisciplinary institution that prioritizes health disparities and global research. The proposed research, training, institution, and mentorship team will support the PI’s pursuit of becoming an independent social epidemiologist focusing on advancing health equity among marginalized adolescent populations.

NIH Research Projects · FY 2025 · 2023-06

Project Summary/Abstract This is a resubmission application for a Mentored Research Scientist Development Award (K01) to support the career development of Dr. Stephanie Matt to facilitate her transition to an independent academic investigator in the HIV and neuroimmunology research fields. An intense and comprehensive mentoring and research plan has been developed to use high-throughput techniques to assess antidepressant-mediated HIV viral dynamics and inflammatory signaling in human myeloid and co-culture models. Dr. Matt’s training will be supported by a firm institutional commitment to her career development and a strong mentoring team of leaders in the HIV and psychoneuroimmunology research fields, each providing strategic guidance in both the development of this proposal and mentoring as her career progresses. The proposed research plan is a natural extension of the recent studies Dr. Matt has been conducting in her mentor Dr. Peter Gaskill’s laboratory but is distinguished by examination of HIV infection and inflammation in clinical cohorts, biostatistical analyses, as well as neuronal profiling. Neurological complications of HIV infection (neuroHIV) remain prevalent even with antiretroviral therapy (ART). Depression is one of these increasingly common complications that can substantively worsen HIV disease progression. Myeloid cells such as macrophages and microglia are primary HIV targets that can serve as viral reservoirs and drive HIV neuropathogenesis, but their activation also mediates depression-associated inflammation. Inflammatory links between HIV, depression, and the drugs used to treat them are not well understood. However, HIV, depression, and antidepressants act on receptors and transporters that alter neurotransmission, and neurotransmitter receptor activity on immune cells can influence inflammatory signaling and HIV infection. This suggests that changes in neurotransmitter levels by antidepressants could affect the size of myeloid HIV reservoirs, exacerbating neuroHIV and influencing the progression of depression and treatment resistance. Thus, the overarching hypothesis of this proposal is that specific antidepressants can activate both CNS and peripheral myeloid cells that critically contribute to inflammation and HIV persistence. This proposal will test this hypothesis using a multifaceted approach to evaluate the effects of in vivo antidepressants and ART on viral dynamics and inflammation in myeloid cells in association with cognitive function in depressed people living with HIV (Aim 1), effects of antidepressants regulating discrete viral dynamics in HIV-infected, ART-treated iPSC CNS and peripheral myeloid populations (Aim 2), and how antidepressants influence viral dynamics and neuronal function in co-cultures of HIV-infected, ART-treated microglia and distinct neuronal subtypes (Aim 3). These studies will significantly advance our understanding of the cellular mechanisms underlying the role of antidepressants in HIV neuropathogenesis. This opportunity will provide comprehensive training and a solid foundation on which to build a successful and independent research program to investigate mechanisms by which neuropsychiatric drugs could drive inflammation in the context of HIV.

NIH Research Projects · FY 2026 · 2023-05

PROJECT SUMMARY A diverse group of autosomal-dominant mutations that cause human blindness as a result of rod and cone degeneration includes multiple mutations in two genes, GUCY2D coding for retinal guanylyl cyclase 1 (RetGC1) and GUCA1A coding for guanylyl cyclase activating protein 1 (GCAP1). These mutations explicitly trigger photoreceptor death via a common mechanism – by abnormally elevating cyclic GMP production in the dark. Although the biochemical origin of the dominant GUCY2D and GUCA1A retinopathies became better understood over the past decade, potential approaches to their therapy, such as using gene editing or RNA interference to suppress particular alleles causing the disease, continue to present a major conceptual challenge. This proposal, conforming to the NEI mission to support research with respect to blinding eye diseases, visual disorders and mechanisms of visual function, explores the foundation of a new approach for the prospective therapy – targeting the common biochemical pathway underlying GUCY2D and GUCA1A dominant retinopathies. The proposal is built on the following main findings: (i) understanding that deregulation of RetGC1 activity is the key to the photoreceptor death caused by the gain-of-function mutations in GUCY2D and GUCA1A; (ii) development of mouse genetic models for studying the biochemical and physiological mechanisms of degeneration incited by the mutant RetGC1 and GCAP1; (iii) recent findings that the abnormal increase in cGMP production that leads to photoreceptor death can be effectively opposed by three different biochemical processes, such as acceleration of cGMP decay in the dark by recombinant phosphodiesterase 5 (PDE5r), stemming RetGC1 activation by GCAP1 using a newly designed protein inhibitor of guanylyl cyclase (PIGC), and enhancing protection of photoreceptors against the presence of deregulated RetGC1 using retinal degeneration-3 (RD3) protein. The research plan of this proposal pursues three Specific Aims, each addressing a new original concept designed to avert photoreceptor dystrophy caused by deregulation of RetGC1. Specific Aim 1 explores the biochemical and physiological mechanisms underlying rescue of photoreceptors in mouse models harboring the degenerative mutants of RetGC1 and GCAP1 using ectopic expression of PDE5r. Aim 2 explores mechanisms of their rescue using PIGC. Aim 3 explores the mechanisms supporting the survival of photoreceptors using RD3. We reason that achieving these Specific Aims will help in developing approaches to the future therapy of the dominant GUCY2D and GUCA1A retinopathies.

NIH Research Projects · FY 2024 · 2023-05

Project Abstract Emerging evidence suggests that certain neurodevelopmental disorders – autism (ASD), attention-deficit hyperactive disorder (ADHD), and intellectual disability (ID) – may increase risk of later life neurodegenerative disorders such as Alzheimer’s disease or related dementia (ADRD), Parkinson’s disease (PD), and amyotrophic lateral sclerosis (ALS). We propose a multinational study of epidemiological and genetic data across the countries of Sweden, Denmark, and the UK to characterize the natural history (Aim 1) and familial aggregation (Aim 2) of these disorders. We also explore genetic links (Aim 3) between neurodevelopmental and later life neurodegenerative disorders, and identify potential targets for intervention that may mitigate risk (Aim 4). Our study will use data from 10+ million persons from Sweden and Denmark with decades of follow-up; iPSYCH, an extensively genotyped case-cohort with ~25,000 ASD, ~30,000 ADHD cases, and 50,000 controls; and a prospective cohort of older adults from the UK (UK Biobank) totaling over half a million persons. Our analytic approach links epidemiological and genetic data, that together, triangulate to answer the question of whether ASD, ADHD, and ID increase risk of ADRD, PD, and ALS.

NIH Research Projects · FY 2026 · 2023-05

Project Summary/Abstract Cocaine use disorder is a chronic disease and currently no approved pharmacotherapies exist for its treatment. Among the greatest challenges in the treatment of cocaine use disorder is prevention of relapse to drug use. In rats, periods of abstinence following cocaine use intensifies seeking and motivation for drug, which has been associated with increased propensity for relapse. Although extensive evidence indicates that mesolimbic dopamine influences cocaine reinforcement, the involvement of dopamine in the regulation of sleep has received comparatively less attention. We recently demonstrated that the dopamine transporter governs diurnal fluctuations in extracellular dopamine tone in the nucleus accumbens and that dopamine uptake fluctuates across the sleep/wake cycle, which impacts the effects of cocaine at inhibiting the dopamine transporter. Moreover, our preliminary and recently published data suggest that sleep disturbances that occur during abstinence promote cocaine seeking and that alterations in dopamine transporter function in the nucleus accumbens may contribute to these effects. Together, these findings raise the possibility that dopamine neurotransmission in the nucleus accumbens may function as a node that integrates both motivational and sleep/wake processes. In the proposed studies, we hypothesize that cocaine-related sleep disruptions during abstinence contribute to dopamine transporter adaptations that promote incubation of cocaine seeking and increase dopamine transporter sensitivity to cocaine. Further, we propose that restoration of rapid-eye movement sleep and/or normalization of dopamine transporter function during abstinence will attenuate incubation of cocaine seeking and reduce dopamine transporter sensitivity to cocaine. Completion of the proposed experiments will offer new insights into the link between sleep disruptions and development of cocaine seeking, and the extent to which this involves alterations in dopamine neurotransmission in the nucleus accumbens. Consequently, expected results should significantly inform the field and help to identify future treatment strategies for cocaine use disorder.

NIH Research Projects · FY 2026 · 2023-04

Candidate: I am an Assistant Research Professor in the Department of Physical Therapy and Rehabilitation Sciences at Drexel University. My long-term career goal is to establish a funded research program as an independent clinician-scientist working to develop evidence-based, pragmatic nonpharmacological programs to manage chronic pain in community-dwelling older adults with Alzheimer’s disease and Alzheimer’s-related dementias (AD/ADRD). To accomplish this goal, I will develop new knowledge and skills in: intervention development; mixed methodologies for intervention development, testing, and refinement; clinical trials using pragmatic and hybrid testing designs; grantsmanship; and research leadership. I will complete the following training objectives: 1) Build expertise in biopsychosocial environmental factors associated with comorbid chronic pain and AD/ADRD; 2) Develop skills in using different qualitative and quantitative methodologies for mapping and developing behavioral interventions that will promote engagement and use of tailored exercise programs by community-dwelling older adults with AD/ADRD; and 3) Gain and apply strategies for developing nonpharmacological pain interventions that have the potential to accelerate the translation of evidence into standard care. Mentoring Team: Joke Bradt, PhD (co-primary), Laura Gitlin, PhD, (co-primary), Peter Gliebus, MD (co-mentor), and Julie Fritz, PT, PhD (co-mentor). Dr. Bradt is a music therapist, Professor and Program Director of the Creative Arts Therapies Program and an expert in chronic pain management and mixed methods research. Dr. Gitlin is Dean and Distinguished University Professor of the College of Nursing and Health Professions and an expert in implementation science and the development of behavioral interventions tailored to the needs of community-dwelling older adults with AD/ADRD and their caregivers. Dr. Gleibus is a neurologist, Associate Professor at Drexel University College of Medicine, Chair of the Department of Neurology, and Director of the Global Neuroscience Institute, with expertise in the interdisciplinary clinical management of AD/ADRD. Dr. Fritz is a physical therapist, Associate Dean for Research and Distinguished Professor at the University of Utah with expertise in developing and implementing exercise-based interventions to manage chronic pain. The mentoring team will guide career development activities, give input, and participate in the K23 research. Research Strategy: The goal of the K23 project is to develop a tailored exercise program prototype to manage knee osteoarthritis pain in community-dwelling older adults with AD/ADRD that is feasible and accepted by key stakeholders. Aim 1: Identify delivery characteristics and design a prototype for a tailored exercise program that is informed in design by the 3-Step Tailored Approach. Aim 2: Assess the feasibility of delivering the tailored exercise program. Aim 3: Evaluate stakeholders’ perceived barriers and facilitators of the tailored exercise program. The proposed study uses an exploratory sequential design and aligns with NIA intervention development Stage I. The study will yield a prototype for a tailored exercise-based intervention program that has been refined for feasibility and acceptability among stakeholders.

NIH Research Projects · FY 2026 · 2023-04

Dysregulation of glutamate transporter-dependent neurovascular coupling in Alzheimer’s disease Decreases in cerebral blood flow, glucose metabolism, and impairment of neurovascular coupling are associated with a number of neurodegenerative disease and cognitive decline, including Alzheimer’s disease and may precede or exacerbate disease. These deficits are also accompanied by loss of glutamate transporters, Na+/Ca2+ exchanger (NCX) isoforms, and deficits in mitochondrial dynamics and Over the last few years, we have demonstrated that astrocytic Glu transporters couple to increases in intracellular Ca2+ through reversed operation of Na+/Ca2+ exchange (NCX). We demonstrated that mitochondria co-compartmentalize with Glu transporters in astrocyte processes and that mitochondrial positioning relative to Glu transporters and synapses is dependent upon Ca2+ and that mitochondria shape Ca2+ signal. Moreover, we found that glutamate transport is sufficient to evoke increases in arteriole diameter (transporter-dependent NVC) downstream of reversed NCX. These and other observations have prompted the central hypothesis that Glu transport and reversed Na+/Ca2+ exchange form a functional signaling pathway in astrocytes that is modulated by mitochondria and that excessive activation of this pathway contributes to pathology observed during the development of AD. In bioenergetics. Aim 1Determine if transporter-mediated NVC is impaired in AD. In Aim 2, we will determine if altered astrocytic mitochondria distribution function effects of AD. Using in vivo imaging or cortical blood flow, local application of glutamate transporters, and selective manipulation (genetic and pharmacologic) of downstream signaling and mitochondrial dynamics, we will dissect the relationship between glutamate transport, NCX, and mitochondria in the control of cortical blood flow and determine if loss of this signaling axis impacts blood flow regulation/neurovascular coupling in AD.

NIH Research Projects · FY 2026 · 2023-04

Screening for autism spectrum disorder (ASD) during well-child pediatric check-ups reduces the age of diagnosis, allowing more time for critical early intervention. Furthermore, universal screening mitigates disparities in the age of diagnosis for minorities, and has been demonstrated to be feasible in community- based primary care settings. However, limited follow-up of toddlers who screened negative is a notable gap in the literature that contributed to the United States Preventive Services Task Force’s (USPSTF) determination of insufficient evidence to recommend universal ASD screening at present. Follow-up of children who are not identified at risk is cost- and labor-intensive, but is critical to determine the sensitivity of toddler ASD screening. This study will be among the first to use rigorous prospective detection strategies in a large, low-risk sample that previously had concurrent detection. The goal of the proposed study is to find missed cases by rescreening children who were not identified with ASD during the course of three prior screening studies that administered the Modified Checklist for Autism in Toddlers, Revised, with Follow-Up during toddler well child visits. This includes those who screened negative as toddlers, as well as children who screened positive but either were lost to follow-up or were evaluated and not diagnosed with ASD. The specific aims are to measure prospective sensitivity using rigorous case confirmation for potential missed cases. We will identify patterns in toddler screening outcomes for these missed cases; we predict that children whose first screen was younger and those who did not complete multiple screens are more likely to be missed cases compared to those screened at older toddler visits and rescreened by age three. Finally, we will examine whether missed cases are more likely to have milder ASD symptoms, greater likelihood of psychiatric comorbidities, and be female compared to children who demonstrated risk as toddlers but were not diagnosed with ASD until they were older. Although these characteristics have been hypothesized, rigorous evidence is lacking to demonstrate differences between children with ASD missed by toddler screening. The majority of the multi-site sample (total n = 8,751) screened negative at one or more pediatric visits between 1 and 3 years old (n = 8,091). In addition, we will rescreen children who screened positive but did not attend the evaluation (n = 426), which often signals lack of parent concern, and children evaluated and classified as nonASD (n = 234), who may have developed clinically significant ASD symptoms as they aged. Parents will be invited to enroll and rescreen their child, now 7-14 years old, using a secure web-based portal. All at risk children, and a random sample of low-risk cases, will be invited for a comprehensive, research-reliable evaluation; final ASD outcomes will be used to calculate prospective sensitivity, which will be compared to literature reporting sensitivity based on record review strategies. Results of this proposed study will directly address a gap identified by the USPSTF, and will address the Interagency Autism Coordinating Committee’s Question 1 about early detection of ASD.

NIH Research Projects · FY 2026 · 2023-04

SUMMARY OF PROPOSAL Modern antiretroviral therapies have transformed Human Immunodeficiency Virus (HIV) infection into a chronically manageable disease. However, a significant amount of people with HIV on antiretroviral therapies present with a spectrum of neurological symptoms. These HIV-associated neurocognitive disorders (HAND) remain an important aspect of modern HIV pathology, prognosis, and clinical management, raising the need for the discovery of adjuvant therapies. Clinical evidence also suggests that HAND can be aggravated by substance abuse, including opioids, which is highly prevalent in people with HIV. Understanding how opioid use contributes to cognitive impairment in HAND will help identify new approaches and drug targets to treat HAND in opioid users. For the past two decades, we have investigated how HIV neurotoxins and opioids contribute to HAND by regulating the chemokine receptor CXCR4 in the central nervous system. We have demonstrated that proper CXCR4 signaling via its natural ligand (the chemokine CXCL12) is not only neuroprotective, but it can also rescue structural (i.e. dendritic spines loss) and functional (i.e. cognitive flexibility) deficits in an animal model of HAND. Further, we discovered that this pathway is hijacked by viral proteins and inhibited by µ-opioid receptor agonists, which revealed a new mechanism whereby opioid use can aggravate HAND. Overall, our body of work demonstrates that the CXCL12/CXCR4 axis is tightly integrated into homeostatic and plasticity processes in cortical neurons, and disruption of CXCR4 signaling via HIV proteins, inflammatory mediators, and opioids is an important component of HAND. For the next (and last) period of this award, we plan to capitalize on this knowledge and other recent findings and fill key gaps in the field that will help us assess the therapeutic value of these discoveries. Thanks to new collaborations, we shifted our focus from molecular mechanisms to network level function – with a main interest in the role of cortical interneurons in HAND. Notably, cortical interneurons dysfunction has emerged as a key factor in neuropsychiatric conditions linked to substance use disorders. Our objectives for the next five years are to determine how interneurons contribute to CXCL12’s regulation of neuronal network activity and cognition in models of HAND, and if the chemokine’s effects are inhibited by morphine via local circuit modulation. Studies in Aim 1 will examine synaptic plasticity deficits that are indicative of microcircuit dysfunction in the medial PFC of WT and HIV-tg rats, and if these network-level deficits are reversed by CXCL12 treatment. Aim 2 studies will examine how dendritic-targeting cortical interneurons that express CXCR4 (namely, SST+ inhibitory neurons) modulate the activity of local networks to enhance neuronal connectivity, and how these processes are affected by inhibitory neurons that express µ-opioid receptors. In Aim 3, we will examine CXCL12/morphine effects in the human brain as a premise to development of new network-based treatments for HAND. As this project aims to understand CXCR4 action at the system level, we will utilize experimental methods that most recapitulate the natural environment of neuronal networks. These include cortical organotypic cultures, where the three-dimensional architecture of the tissue is preserved and in vivo studies to measure cognitive flexibility, coupled to ex vivo analyses, as described in detail in the attached proposal. Based on unexpected new findings concerning CXCR4 expression in mature individual neurons, we hypothesize that CXCL12 action relies on microcircuit mechanisms that regulates both synaptic plasticity and cognition. Our working hypothesis is that CXCL12 signaling primes CXCR4+ somatostatin expressing interneurons in microcircuits to optimally respond to different stimuli and improves network connectivity. Conversely, morphine acts on larger contingent of interneurons, including CXCR4+ interneurons, ultimately causing local networks to scale back synaptic connections. This project will reveal the role of cortical interneurons in cognitive deficits in HAND and test new concepts in the chemokine/opioid relationship (i.e. not limited to cell autonomous mechanisms) that have a broad range of consequences for substance use disorders.

NIH Research Projects · FY 2026 · 2023-04

Project Summary Over the last two decades, breakthroughs in sequencing technologies have revealed that mammalian genomes encode thousands of long non-coding RNAs (lncRNAs). The numbers of human lncRNAs that are known to be dysregulated in diseases are rising at a rapid pace. Emerging evidence suggests that lncRNAs are critical regulators of fundamental cellular processes and disease progression. Despite their significance as potential biomarkers and therapeutic targets, the molecular mechanisms of lncRNAs remain poorly understood. The primary goal of this research is to elucidate in greater detail the mechanisms by which lncRNAs activate transcription. Many lncRNAs are associated with epigenetic machinery; these include histone-modifying complexes, such as the polycomb repressive complex 2, and nucleosome remodeling complexes, such as the SWI/SNF (SWItch/Sucrose Non-Fermentable) complex. While the RNA-PRC2 interactions are under active investigation, the role of lncRNAs in nucleosome remodeling remains uncharacterized. Here, we seek to understand the function of lncRNAs in SWI/SNF-based gene activation. The SWI/SNF complex is a known tumor suppressor, and its subunits are mutated in various cancers. Recently, lncRNAs have been shown to interact with the SWI/SNF complex in mammals and plants. In this proposal, we will utilize lncTCF7 to investigate the role of lncRNAs in SWI/SNF-based gene activation. Previous studies have shown that lncTCF7 activates Wnt signaling by recruiting the SWI/SNF complex. However, the biochemical and structural basis of these interactions is not established. In preliminary studies, we identified SND1 (Staphylococcal Nuclease and Tudor Domain Containing 1) as the top interaction partner of lncTCF7. SND1 is a transcriptional coactivator, and it is known to associate with the SWI/SNF family. Here, we propose a novel mechanism suggesting that lncTCF7 recruits the SWI/SNF complex indirectly via its interaction with SND1. Further, our RNA chemical probing studies identified structural domains and regions of lncTCF7 conserved across mammalian genomes. We hypothesize that these conserved regions and structured elements play critical roles in recruiting protein partners and activating transcription at specific loci. We will test this hypothesis through the following aims: In Aim 1, we will define the functional role of lncTCF7’s domains. Aim 2 will determine the role of lncTCF7-SND1 interaction in recruiting the SWI/SNF complex and activating transcription. In Aim 3, we will determine the 3D structure of lncTCF7 and the lncTCF7-SND1 complex. Together, these studies will provide biochemical and structural knowledge of lncTCF7’s molecular function and expand our understanding of how lncRNAs regulate gene transcription and contribute to disease states.

NIH Research Projects · FY 2025 · 2022-09

ABSTRACT Locomotion is a fundamental behavior that allows humans and animals to move through their environments and is critically involved in all aspects of life. This behavior is impeded in a number of diseases, disorders, and injuries, including spinal cord injury, stroke, and various ataxias. All of the essential circuity to generate locomotor rhythm and pattern is located in the thoracolumbar spinal cord, most often below the level of neural damage. These circuits can be accessed directly via various central and peripheral stimulation methods, including but not limited to epidural stimulation. Rhythm generating circuits are the entry point for initiation and control of locomotion, affect all downstream neurons related to locomotion, and, therefore, are the first step in establishing spinal control of locomotion. Successful activation of the rhythm generator clinically has been hampered because the mechanisms by which spinal neuronal circuits generate coordinated rhythmic output remain poorly understood and represents a major gap in our understanding of neural control of movement. The generation of rhythmic motor behaviors is based on a triad involving: (1) specific “rhythmogenic” properties allowing individual neurons to generate rhythmic oscillations, (2) mutual excitatory interactions to synchronize neuronal activity into rhythmic populational bursting, and (3) network inhibition to coordinate activity between different neuronal populations, which can both shape locomotor pattern and control frequency. Triad components are highly interconnected and the involvement of each component is condition-dependent. The proposed study will use highly integrated electrophysiological, pharmacological, genetic, and computational approaches to systematically explore the specific contributions of these mechanisms and the interactions between them, in the generation and patterning of the locomotor rhythm. Utilizing spinal neurons identified in transgenic mice by the transcription factor Shox2 as a representative rhythm generating population, we will test the overarching hypothesis that rhythm generating mechanisms in the spinal cord involve interplay between the triad of cellular, population, and network properties, whose contribution to rhythmogenesis is interdependent, leading to flexibility and adaptability seen as alterations in the relative balance of the triad in different conditions. We will first determine the voltage-gated currents underlying spontaneous cellular oscillations in adult Shox2 neurons. We will then assess excitatory interactions between rhythm generating neurons. Lastly, we will establish the role of ipsilateral and contralateral network interactions in regulating locomotor frequency, and determine the operation of these pathways during afferent-evoked locomotion. Together, our multidisciplinary study will reveal mechanisms of rhythm generation, establish the first mammalian locomotor neural network model based on “real” rhythm generating cellular and network properties, and determine the ways by which afferent stimulation may influence the locomotor rhythm and pattern generated in the spinal cord. The results of these studies will identify specific neural targets for the future devices and strategies aimed at restoration of locomotion following injury or motor disorders.

NIH Research Projects · FY 2025 · 2022-09

Abstract Complex regional pain syndrome (CRPS) is a chronic pain disorder of unknown etiology that can affect one or more extremities. Difficulty in treating CRPS stems from incomplete understanding of the underlying mechanisms. Despite different clinical presentations, clear evidence for altered processing of sensory stimuli leading to allodynia, hyperalgesia, and hyperaesthesia has been demonstrated in CRPS. Aberrant immune function is reported to contribute to CRPS pathology. Autoinflammatory and autoimmune mechanisms in the skin of the affected limb, and systemically in circulation, reportedly contribute to increased pain hypersensitivity. Systemically, CRPS patients have increased proinflammatory monocytes, and altered circulating memory T cells (Tcircm). An expansion of long-lived central memory CD8+ and CD4+ T cells with increased proinflammatory signaling is reported in CRPS patients. However, current studies on Tcircm do not account for local tissue-resident memory T cells (Trm) which have been implicated in several autoimmune disorders. Cluster of differentiation 69 (CD69) is a type II C-lectin membrane receptor that is rapidly induced upon T cell activation, enabling their accumulation in nonlymphoid tissues like skin. CD69 antagonizes the cell-surface expression of G-protein– coupled sphingosine-1-phosphate receptor-1 and 5 (S1PR1/5). By inhibiting the expression of S1PR1/5, CD69 impairs egress and promotes T cell residency. We have identified dysregulation of circulating miRNA signatures common to both CRPS patients and mouse tibia fracture model (TFM) of CRPS that can regulate Tcircm. Interestingly several miRNAs, including a miRNA directly associated with positive outcomes for CRPS patients, can target genes critical to Trm development. This led us to evaluate Tcircm and Trm dysfunction in TFM mice, where preliminary data demonstrate formation of pathological Trm in TFM mice. We hypothesize that dysregulation of T cells in CRPS converges on targets crucial for both Tcircm homeostasis and Trm formation. We will test whether pathological Tcircm and Trm contribute to CRPS pathology, and if therapies that cooperatively target both populations can serve as a novel therapeutic strategy. By following Tcircm and Trm, we will elucidate mechanisms of T cell dysfunction and investigate novel immune modulating therapies for treating CRPS.

NIH Research Projects · FY 2025 · 2022-09

Latinos in the U.S. experience significant barriers to access mental health services due to lack of health insurance, cost of services, limited awareness of mental health resources and mental health stigma. Limited English proficiency coupled with an acute lack of bilingual providers further impede Latinos’ adequate access to quality mental health services. The COVID-19 pandemic has only amplified the need for mental health care and exacerbated mental health conditions for Latino communities, making it urgent to identify low-cost, effective strategies to reduce these gaps. This 5-year project seeks to develop and test a multi-level, community intervention to improve mental health outcomes and promote access to appropriate mental health treatment for Latino communities in Philadelphia. CRISOL Mente will include components at various levels of the socio-ecological model: a clinic-based, stepped-care program relying on Latino lay health workers (LHW) for the delivery of mental health services (Aim 1), outreach and education activities to reduce mental health stigma in the community (Aim 2), and efforts to strengthen service providers’ capacity to address mental health and other syndemic conditions contributing to untreated mental health among Latinos (Aim 3). To improve mental health symptoms and engagement in care, we will recruit, train and supervise a cohort of Latino LHW who will be embedded into two community-based clinics, extending the reach and effectiveness of the clinics’ mental health services. We will compare the impact of three different levels of LHW involvement: a) community outreach/navigation (i.e. screening and referral of community members); b) auxiliary care (i.e. screening, referral, and help overcoming barriers to better mental health); and c) task shifting (i.e. screening, referral, assistance, and supervised delivery of basic mental health treatment). The LHWs will also conduct outreach/education activities in the community (e.g. radio talks, info sessions, tables in community venues) to reduce mental health stigma. Our experienced and largely Latino community-academic research team will also engage in capacity building activities (i.e. monthly town halls, annual retreats, weekly newsletters, provision of trainings and technical support) with the Latino Health Collective, a coalition of community-based organizations (CBOs). Using mixed-methods and the RE-AIM framework, CRISOL Mente’s impact will be evaluated with clinical data, baseline and 6-month patient survey data (N=200 from each level of LHW involvement), and qualitative interviews with community members (N=30) referred to mental health services by the LHW (Aim 1); pre/post mental health stigma data from two respondent driven sampling (RDS) surveys of Latinos (N=400 each) conducted in 2022 (preliminary study) and in 2027 (Aim 2); community capacity indicators from three surveys of CBOs conducted in 2019, 2021 (preliminary studies) and 2027, and key informant interviews (KII) with service providers (N=30) in 2019 (preliminary study) and 2027 (Aim 3).

NIH Research Projects · FY 2025 · 2022-09

One of the principal obstacles to curing HIV is the existence of viral reservoirs in distinct compartments and cell types that are unaffected by antiretroviral therapy (ART). In the central nervous system (CNS), these reservoirs are comprised of myeloid cells, such as perivascular macrophages and microglia. Critically, these reservoirs are generally established prior to the initiation of ART and the presence of ART in the CNS does not affect the established reservoir in long-lived myeloid populations. Thus, even in individuals on suppressive ART, persistently infected CNS macrophages and microglia can drive ongoing neuroinflammation and provide a source of HIV for viral recrudescence during medication hiatus or failure. Our ability to eliminate these reservoirs is severely limited by the lack of understanding of the transcriptional and epigenetic regulation of HIV in myeloid cells. To effectively target and eliminate CNS reservoirs in people living with HIV (PLWH), it is critical to define the transcriptional mechanisms mediating persistent infection in distinct CNS myeloid populations. The impact of HIV infection in the CNS is heightened in PLWH who have substance use disorders, including those who take and/or misuse therapeutic drugs such as benzodiazepines (BDZ). Benzodiazepines are used by more than 30 million Americans, have high abuse liability and misuse of these drugs accounts for 15 – 20% of their use. Benzodiazepines are prescribed to a growing number of PLWH and are associated with an increased risk of neurocognitive symptoms in this population. Little is known about the mechanisms by which BDZ impact HIV neuropathogenesis. Our published and preliminary data indicate that BDZ can alter the transcriptional regulation of HIV infection. To better understand and treat the development of neuroHIV in PLWH who use and/or misuse BDZ, it is vital to determine who benzodiazepines affect the transcriptional programs in myeloid cells. We hypothesize that both macrophages and microglia enter a semi-quiescent transcriptional state during ART exposure and that benzodiazepines disrupt this state and increase transcriptional activity and viral replication. Our data show that the BDZ Xanax, as well as some latency reactivation agents, mediate a dose-dependent increase in p24 production in infected, ART-treated cells. Our preliminary studies suggest these effects may result from BDZ interactions with the epigenetic regulator RUNX1. We posit that these changes in HIV replication in myeloid cells reflect the epigenetic state of the provirus. Thus, the growing population of PLWH who use BDZ is at greater risk of more severe neuropathogenesis. It also suggests that BDZ may provide the basis for novel therapeutics to manipulate HIV transcription in myeloid cells. Therefore, we will evaluate the transcriptional and epigenetic mechanisms sustaining the semi-quiescent state of HIV transcription in ART- treated human macrophages (Aim 1), define the differences in transcriptional and epigenetic processes in different types of myeloid cells using human syngeneic iPSC-derived macrophages and microglia (Aim 2), and examine the effect of benzodiazepines on transcription HIV-infected, ART-treated myeloid cells (Aim 3).

NIH Research Projects · FY 2024 · 2022-09

Although difficulty with nonverbal communication (NVC) is required for a diagnosis of autism at any age, no evidence-based interventions exist specifically targeting these skills beyond toddlerhood. Thus, older children and adults on the autism spectrum remain unsupported for a core challenge with wide-reaching func- tional impacts. Our long-term goal is to develop and implement targeted interventions to improve NVC expe- riences for autistic adults, yet two gaps in knowledge exist. First, before developing novel NVC interventions, it is critical to evaluate prospective intervention options from the perspectives of autistic adults themselves; what autistic adults want out of intervention remains unknown. Significant resources could be wasted if interventions are developed without consulting the communities who will one day seek to benefit from them. Second, due to the heterogeneity inherent to autism, a “one size fits all” intervention is not a realistic goal; rather, distinct profiles of ability and disability are likely to map onto different intervention priorities, which could facilitate targeted, indi- vidualized intervention development. This grant will address these gaps by establishing foundational knowledge about (1) how autistic adults experience NVC, (2) what they want out of intervention, and (3) how patterns of individual difference map onto patterns of impact and intervention priority. We will use an explanatory-sequential mixed methods design (Quantitative → Qualitative), in consultation with autistic members of a community-aca- demic collaborative, with two specific aims: (1) Discover data-driven behavioral profiles relevant to NVC impact and desire for intervention that will inform how to best match individuals to interventions; and (2) Understand autistic adults’ perspectives on NVC experience and intervention qualitatively. In Aim 1, a diverse sample of autistic adults (n=400) will complete surveys about their communication skills, NVC experiences, and desire for intervention. Machine learning regression and canonical correlation analysis will model individual predictors of NVC impact and desire for intervention and identify combinations of individual differences most predictive of contexts for which NVC intervention is desired. In Aim 2 we will re-recruit n=40 survey participants to complete follow-up semi-structured interviews about their Aim 1 responses. Interviews will elucidate the specific nature of problematic and successful NVC interactions; reasons why intervention is and is not desired; and preferred in- tervention targets and formats. We will analyze interview data using thematic analysis; findings will be used to develop community-drafted guidelines for NVC intervention development. Contributions will be significant be- cause they will provide strong empirical and community-based justification for investing resources in support of the adult autistic community. This research is innovative because it represents a substantive departure from the status quo by starting with the opinions, experiences, and perspectives of the target population. Knowledge generated will parse the heterogeneity of communication skills in autism, and has the potential to guide devel- opment of individualized interventions to meet the greatest areas of need with the greatest chance of success.