Drexel University

NIH Research Projects · FY 2024 · 2024-08

Project Summary Conformational variations in α-syn fibrils are proposed to be implicated in the emergence of distinct diseases within synucleinopathies, including Lewy body dementia (LBD), Parkinsons’s disease (PD), and multiple system atrophy (MSA), suggesting a molecular fingerprint closely connected to clinical diagnosis. However, the mechanisms underlying the appearance of these disease-specific conformations and their impact on the progression of distinct pathologies in synucleinopathies remain largely unclear. Motivated by the existing knowledge gap between structural polymorphism and disease entities, the goal of this proposed research is to investigate how α-syn pathology propagates in a disease-specific manner, by focusing on the molecular interactions between α-syn fibril structures and diverse cellular environments. To achieve this, we will employ a multidisciplinary approach based on the combination of biophysical approach, molecular biology, and human organ-on-a-chip technology. Building upon our complementary expertise in neurodegenerative amyloid fibril research and human organ-chip development, we will produce various forms of α-syn fibril seeds, characterize their conformations, and investigate their functions in human vascularized brain-on-chips with an unprecedented physiological realism. The central hypothesis posits that the membrane-mediated polymorphisms of α-syn fibrils are a key factor in the emergence of the distinctive pathological features of synucleinopathies, including LBD and PD, through the molecular interactions between α-syn fibrils and cellular membranes. These interactions are significantly influenced by the distinct conformations of α-syn fibrils and the varying membrane conditions found in different types of brain cells. This hypothesis will be tested by pursuing three specific aims: 1) Generate the polymorphic α-syn fibrils in the presence of various physiologically relevant membranes and characterize their functional properties; 2) Create microengineered 3D culture arrays for on-chip production of vascularized human mid-brain tissues and validate the propagation of α-syn pathology; and 3) Explore the cell-type specific pathological impacts of lipid-associated polymorphic α-syn fibrils and compare the molecular structures and interactions of these polymorphic α-syn fibrils. The expected outcomes will provide novel insights into the molecular mechanisms underlying conformation-dependent neuropathology. Consequently, these findings will contribute to the design and development of small molecules aimed at either inhibiting aggregations or detecting neurotoxic aggregates. Additionally, the brain-on-a-chip established in this study has the potential to serve as a promising drug screening platform capable of faithfully replicating cellular responses to pharmaceutical agents. Ultimately, this study will aid in the development of advanced diagnostic and therapeutic approaches aimed at synucleinopathies, thereby mitigating the adverse impacts of neurodegenerative disorders on public health and societal functioning.

NIH Research Projects · FY 2025 · 2024-08

PROJECT SUMMARY HIV infection results in abnormal menstruation and alterations in circulating hormones. HIV infection is also highly comorbid with drug use. Women who use drugs are at an elevated risk of HIV infection and show accelerated HIV progression. In rodents, estrous cyclicity and cocaine-related behaviors are both regulated by the medial preoptic area (mPOA) of the hypothalamus. The mPOA regulates gonadal hormone release which feeds back onto the mPOA to regulate its activity. The mPOA regulates cocaine-related behaviors through primarily GABAergic projections to the ventral tegmental area (VTA), which modulates dopamine release in the nucleus accumbens (NAc). Lesion of the mPOA disrupts estrous cycling and enhances cocaine-induced locomotion. These mPOA lesion-induced changes are associated with increased cFos expression and dopamine release in the NAc, together implicating mPOA in both estrous cyclicity and cocaine-related behavior. Our preliminary data in the EcoHIV mouse model of HIV infection indicate disruptions in estrous cycle following inoculation with EcoHIV. Further, EcoHIV infection enhanced cocaine-induced locomotor sensitization, a model of cocaine- related behavioral plasticity, and increased cocaine-induced cFos expression in the NAc. Thus, the mPOA may represent a common site of dysregulation following EcoHIV infection, leading to alterations in both estrous cycle and cocaine-related behavior. Consistent with this, we have observed that EcoHIV-infected female mice exhibit attenuated cFos expression in the mPOA. This R21 proposal will test the overarching hypothesis that EcoHIV infection dysregulates the mPOA estradiol system, leading to enhanced cocaine-induced locomotor sensitization. Aim 1 will determine the effects of EcoHIV inoculation and cocaine exposure on estradiol levels and receptor expression in the mPOA. Aim 2 will determine the effects of EcoHIV inoculation on engagement of mPOA→VTA and VTA→NAc projections in cocaine-induced locomotor sensitization. Aim 3 will determine the effect of chemogenetic activation of mPOA→VTA projections on cocaine-induced locomotor sensitization following EcoHIV infection. It will also determine the effect of an estrogen receptor α antagonist on cocaine- induced locomotor sensitization following EcoHIV infection. The results of these experiments will identify a mechanism by which EcoHIV infection alters behavioral response to cocaine and the contribution of the mPOA→VTA→NAc pathway to cocaine-related behavior following EcoHIV infection. Further, we will gain significant knowledge of sex differences in the regulation of cocaine-related behavior by the hypothalamus.

NIH Research Projects · FY 2025 · 2024-07

Per-and polyfluoroalkyl substances (PFAS) are detected in virtually all people in the U.S. and the evidence of health effects at increasingly low levels of PFAS, is growing. Despite being used in manufacturing since the 1940s, there was little awareness or research on the health effects of PFAS until the last 15 years. A 2016 National Toxicology Program (NTP) systematic review concluded that PFOA and PFOS are a presumed immune hazard to humans. In particular, decreased antibody response has been identified as a critical endpoint for international, national, and state toxicity values and drinking water regulations. Despite the regulatory importance, research on the health consequences resulting from reduced immune function is not definitive. Common childhood infections and immune hypersensitivity outcomes such as allergies are useful measures for evaluating altered immune function in humans, and notably, no U.S. based cohort study has evaluated these outcomes. Combing pediatric birth cohorts with available prenatal PFAS serum concentrations from across the Environmental Influences on Child Health Outcomes cohort, we will evaluate associations with childhood infections (bronchiolitis, croup, pneumonia and bronchitis, ear infections) and allergies (allergy symptoms, and atopic dermatitis) at infancy and early childhood. PFAS will be evaluated individually in adjusted linear and logistic regression models and as mixtures using Bayesian Kernal Regression Models (BKMR). Potential effect modification by breastfeeding, child sex, child BMI, and other factors will be evaluated to understand differential impacts due to cumulative exposures. Dietary and demographic determinants of PFAS will be assessed with correlation analysis and multivariable linear regression across the ECHO-wide study and for each cohort to provide targets for further reduction of PFAS exposure in U.S. pregnant women. Positive and null findings, alike, from well conducted studies, will be important for understanding safe levels of exposure and guiding future regulations.

NIH Research Projects · FY 2025 · 2024-07

ABSTRACT: Spinal cord injury (SCI) results in the devastating loss of motor, sensory, and autonomic function below the level of the lesion. Importantly, most SCIs occur in the cervical and thoracic levels, leaving the locomotor circuits in the lumbar segments, and sensory afferents below the injury, relatively intact. While these circuits may not be directly affected by the injury, the loss of descending control can lead to changes in excitability, afferent sprouting, and other compensatory changes. Regaining proper control of locomotor circuits after injury is crucial for restoration of efficient locomotion, yet many of the specific circuit rearrangements induced by SCI remain unknown. Inhibitory interneurons (INs) in the dorsal horn of the spinal cord finely tune incoming sensory afferent input, and are a possible target for modulating afferent transmission to locomotor circuits after injury. Specifically, INs regulating proprioceptive afferents are of great interest due to the importance of proprioception on locomotor recovery after SCI. Locomotor circuits are comprised of spinal INs that control the pattern and rhythm of locomotion, one population of which expresses the transcription factor Shox2. We have evidence that sensory afferent pathways to Shox2 INs are a point of plasticity after SCI and treatment with epidural stimulation. Specifically, the loss of the inhibitory sensory pathway to Shox2 INs after SCI suggests that inhibitory INs interposed between sensory afferents and Shox2 INs are a potential novel target for improving locomotion after SCI. Understanding the function of this population, and the mechanisms behind the plasticity of inhibitory sensory pathways to locomotor circuits may then allow for proper modulation after injury to restore proper control of locomotor circuits. The proposed experiments will test the overall hypothesis that medial laminae V/VI glycinergic INs are required for skilled locomotion, and an SCI-induced disruption of proprioceptive afferent input to them is responsible for the observed dysregulation of afferent pathways to Shox2 INs after SCI. Using a combination of whole-cell patch clamp, pharmacology, and histology we will identify known deep dorsal inhibitory populations that overlap with glycinergic INs interposed between sensory afferents and Shox2 INs. Then we will chemogenetically silence this population of glycinergic INs during skilled locomotor tasks. Together, these experiments will allow us to functionally identify medial lamina V/VI glycinergic INs. Next, we will use a combinatorial approach to investigate the mechanism underlying the loss of inhibitory sensory afferent pathways to Shox2 INs after SCI. Electrophysiology, neural tracing, and immunohistochemistry will be used to evaluate the proprioceptive afferent input to medial laminae V/VI glycinergic INs and, Shox2 INs after SCI. The findings from this proposal will provide insight into the role of a specific population of inhibitory INs, and the mechanistic underpinnings of plasticity within inhibitory sensory pathways to locomotor circuits. This knowledge will be vital to identify novel therapeutic targets, and guide strategies to restore locomotion after SCI.

NSF Awards · FY 2024 · 2024-07

Unexpected “shocks,” or abrupt deviations from periods of stability naturally occur in time-dependent data-generating mechanisms across a variety of disciplines. Examples include crashes in stock markets, flurries of activity on social media following news events, and changes in animal migratory patterns, among countless others. Reliable detection and statistical analysis of shock events is crucial in applications, as shock inference can provide scientists deeper understanding of large systems of time-dependent variables, helping to mitigate risk and manage uncertainty. When large systems of time-dependent variables are observed at high sampling frequencies, information at fine timescales can reveal hidden connections and provide insights into the collective uncertainty shared by an entire system. High-frequency observations of such systems appear in econometrics, climatology, statistical physics, and many other areas of empirical science that can benefit from reliable inference of shock events. This project will develop new statistical techniques for both the detection and analysis of shocks in large systems of time-dependent variables observed at high temporal sampling frequencies. The project will also involve mentoring students and organizing workshops. The investigators will study shock inference problems in a variety of settings in high dimensions. Special focus will be paid to semi-parametric high-frequency models that display a factor structure. Detection based on time-localized principal component analysis and related techniques will be explored, with a goal towards accounting for shock events that impact a large number of component series in a possibly asynchronous manner. Time-localized bootstrapping methods will also be considered for feasible testing frameworks for quantifying the system-level impact of shocks. Complimentary lines of inquiry will concern estimation of jump behavior in high-frequency models in multivariate contexts and time-localized clustering methods. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NSF Awards · FY 2024 · 2024-07

NON-TECHNICAL SUMMARY Tiny groupings of solute atoms at the nanometer scale in materials are referred to as "solute clusters," and they have the potential to dramatically improve the strength of metal alloys. This process has been recognized only in the last two decades and is not yet fully understood, especially when compared to more conventional strengthening methods, such as precipitate strengthening, which involves growing hard particles in alloys to make them stronger. In this work, Mg alloys are selected as the model system. The goal of this research is to understand when and why the nanoscale clustering of solute atoms can work better than other strengthening mechanisms. It is anticipated that certain types of solute clusters, based on their chemical compositions and spatial arrangements, can be particularly potent at blocking the movement of dislocations, which are line defects in alloys that accommodate plastic deformation. Via a combination of advanced experimental characterization and computer simulation techniques, the research will be carried out in the following steps: first, to understand the structure and spatial dispersion of solute clusters; next, to elucidate how these solute clusters interact with dislocations at the nanometer scale; and finally, to quantify how much stronger these solute clusters can make the metal macroscopically. This research could lead to a new theory to quantitatively predict metal strength based on the presence of these solute clusters. The significance of this research lies in its potential to advance our knowledge of alloy strengthening, which could result in the development of stronger and lighter metallic materials for everything from cars to planes. It also includes educational outreach, such as engaging students of various age groups and the public with materials science and creating new learning opportunities in the field. TECHNICAL SUMMARY Recognizing solute cluster strengthening as a novel strengthening mechanism, the goal of the project is to address the knowledge gap in quantitatively modeling and understanding the interactions between solute clusters and dislocations at the atomistic level and the subsequent macroscopic yield strength enhancement. Using Mg as the model system, the project's objective is to elucidate the fundamental mechanisms underpinning solute cluster strengthening through a multiscale approach and to develop a quantitative predictive model of the associated strengthening stress. One key scientific question to be tackled is why solute clustering is more effective than traditional precipitate strengthening under certain conditions. The hypothesis is that specific solute cluster configurations and chemistries offer superior strengthening effects compared to both a superposition of individual solute atoms in a randomized solid solution and precipitates containing an equivalent number of solute atoms. To validate this hypothesis, the following research activities are proposed: atomic-scale prediction and identification of solute cluster chemistry and structure; nanometer-scale modeling and characterization of dislocation-cluster interactions; and continuum-scale prediction and measurement of the critical resolved shear stress enhancement due to solute clusters across different slip systems. By integrating computational simulations with experimental validation, the proposed research seeks to develop a transformative multiscale model that integrates the intricate atomic-level details of cluster-dislocation interactions for quantitative modeling of dislocation slip mechanics and prediction of flow stress. Moreover, this research will offer insights into the specific scenarios wherein solute cluster strengthening outperforms conventional precipitate hardening. The anticipated outcome is a new physical model that complements existing alloy strengthening theories, advancing the field of materials science and the development of alloys with enhanced mechanical performance. The educational component of the project will promote engagement with K-12 and underrepresented student groups, facilitating their participation in science and engineering through special events and student exchange programs. Additionally, the development of a new summer school course on multiscale modeling of structural materials will further reinforce the nation's scientific and engineering workforce competitiveness. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NIH Research Projects · FY 2024 · 2024-07

Project Summary Each year, millions of US renters are legally evicted from their homes, with structurally marginalized groups – particularly Black and Latinx women – bearing the highest burden of evictions. Past research has shown that personal exposure to eviction worsens physical and mental health via multiple pathways. Recent research also suggests that eviction may create spillover effects on neighborhood health by increasing physiologic and psychosocial stress (related to potential housing loss) and by eroding protective social structures within communities. While individual and/or neighborhood exposure to eviction may make it more difficult to prevent and/or manage highly prevalent stress-sensitive chronic conditions such as cardiovascular diseases (CVD), few studies have examined how eviction influences CVD-related outcomes. Moreover, no studies have used multilevel modeling to: (1) examine if neighborhood eviction rates affect individual-level CVD-related outcomes; (2) test whether effects are worse for marginalized groups; or (3) parse out individual and spillover effects of eviction on health. Lastly, few studies have used qualitative approaches to understand renters’ views on how eviction affects health. Clarifying these relationships can inform practice and policy interventions by deepening our knowledge of evictions’ effects on health equity. This study has two main objectives. First, using linked data on neighborhood eviction rates (Eviction Lab) and individual-level health outcomes (from Panel 21 of the Medical Expenditure Panel Survey), I will use multilevel models to (1) examine whether neighborhood eviction rates are associated with individual-level CVD-related hospitalizations over time and (2) examine how these associations vary by race/ethnicity and gender. Second, using data from an NIH-funded cohort study of 400 low-income adults in New Haven, CT, and newly collected qualitative data, I will conduct an explanatory- sequential, mixed-methods study to: (1) examine how individual and neighborhood exposures to eviction affect risk factors (smoking; psychological distress) and protective factors (social support; ambulatory care use) pertinent to CVD prevention and management, and (2) understand participants’ views on health-related effects of eviction. Informed by my clinical practice and my prior research, which includes a scoping review on eviction and health, my central hypothesis is that neighborhood eviction rates will be associated with worse individual- level CVD-related outcomes, that effects will be particularly strong for members of structurally marginalized groups, and that participants will identify stress and compromised social support as key mechanisms through which eviction affects health. Findings may inform the development and implementation of policies and practices to prevent evictions and reduce their impacts on health. The proposed training plan will enhance my conceptual knowledge, my skills in multilevel modeling, and my ability to translate research findings to policy and practice. This research is vital in the wake of the COVID-19 pandemic, which has intensified low-income renters’ risk of eviction, widened pre-existing inequities, and underscored the importance of housing for health.

NIH Research Projects · FY 2025 · 2024-07

Project Summary/Abstract Cocaine use disorders (CUDs) and human immunodeficiency virus (HIV) are persistent public health concerns worldwide. Psychostimulants such as cocaine can facilitate viral replication and neuroinvasion into the central nervous system, which can exacerbate HIV-associated neurocognitive dysfunction that is observed even among those virally suppressed under antiretroviral therapy (ART). Unlike other addictive substances, cocaine does not have effective FDA-approved medications for helping individuals reduce their cocaine use or maintain long-term abstinence. Moreover, it is possible that comorbidities such as HIV may impair the efficacy of medications that may be otherwise effective at treating CUDs (e.g., Namba et al., 2023, Addiction Neuro.). Taken together, identifying the unique cellular- and circuit-specific mechanisms underlying drug seeking and relapse-like behavior in the context of HIV is imperative for developing targeted and effective treatments for vulnerable subpopulations of individuals, such as PLWH suffering from CUDs. This proposal aims to elucidate corticostriatal and neuroimmune mechanisms underlying HIV-induced dysregulation of reward seeking, with the ultimate goal of identifying novel CUD treatment targets for PLWH. My preliminary work has revealed that mice infected with the chimeric HIV construct, EcoHIV, display potentiated cocaine-seeking behavior, impaired extinction learning, as well as dysregulated peripheral and corticolimbic neuroimmune function. A wide breadth of studies demonstrate that activity of neuronal projections from the infralimbic cortex (IL) region of the prefrontal cortex (PFC) to the nucleus accumbens shell (NAcSh) are necessary for both the acquisition and expression of extinction learning and facilitate refraining from drug seeking. As well, PFC dysfunction is also heavily implicated in HIV at both the clinical and preclinical level. In Aim 1 of this proposal, I will use circuit-specific, closed-loop optogenetics to stimulate the IL→NAcSh circuit to rescue EcoHIV-induced deficits in extinction learning in male and female mice. Given the putative role of microglia in HIV-associated neuropathology, I will also explore EcoHIV- and cocaine-induced plasticity of NAcSh microglia in Aim 2. Here, I will employ a combination of designer receptors exclusively activated by designer drugs (DREADDs) expressed specifically in microglia with quantitative microglial morphometry to 1) characterize how microglial morphology changes due to cocaine and EcoHIV infection and 2) determine whether Gi-coupled DREADD stimulation on microglia suppresses EcoHIV- induced potentiation of cocaine seeking. This research has the potential to reveal novel corticolimbic circuit and neuroimmune mechanisms underlying HIV-induced dysregulation of reward-seeking behavior, which will advance our understanding of, and identification of treatment targets for, comorbid HIV and CUDs. Throughout the proposed training period, I will be trained in techniques such as mouse stereotaxic surgery, closed-loop optogenetics, chemogenetics, and quantitative imaging and analysis of microglial morphology.

NIH Research Projects · FY 2026 · 2024-06

Malaria remains a major global health burden, affecting 40% of the world’s population. In 2021, there were 247 million reported cases, resulting in over 619,000 deaths. The disease is caused by repetitive growth of the protozoan parasites known as Plasmodium spp. inside red blood cells (RBCs), leading to RBC lysis. Among the five malaria species infecting humans, Plasmodium falciparum is the most lethal, responsible for more than 80% of the disease’s morbidity and mortality. This parasite undergoes asexual reproduction within RBCs over its 48-hour lifecycle, which consists of three major stages: the ring stage (~ 20 hours), the trophozoite stage (~ 16 hours) and the schizont stage (~12 hours). During the ring stage, infected RBCs (iRBCs) have a smooth surface like uninfected RBCs, enabling them to evade clearance by the spleen and circulate in the peripheral bloodstream. This stage is metabolically quiescent and challenging to target with available antimalarials, as most of these drugs are not highly effective against the slow-growing parasite. Furthermore, the ring stage can enter a dormant state after drug treatment, contributing to drug resistance. Therefore, there is an urgent need for a better understanding of the fundamental biology of ring stage malaria parasites. Our laboratory has made a significant discovery by revealing that the metabolically inactive ring stage parasite employs an ancient pyrophosphate-driven proton pump to survive for 20 hours inside the RBC following the time of invasion. This ATP-independent proton pump is known as PfVP1 (Plasmodium falciparum vacuolar pyrophosphatase 1), and it derives energy from the hydrolysis of pyrophosphate (PPi), a metabolic by-product generated during synthesis of DNA, RNA, and protein. Based on these observations, we hypothesize that the ring-stage P. falciparum relies on an ATP-independent mechanism for proton exporting and establishing plasma membrane potential, identifying a distinctive vulnerability in this challenging stage of the asexual lifecycle. To test this hypothesis, we outline two specific aims. Aim I. Investigate the impact of PfVP1’s loop sequences on its proton pumping functionality. Aim II. Examine polyphosphate metabolism and PPi metabolism to understand the energy source for PfVP1. The outcomes of this research proposal will provide insights into how the metabolically quiescent ring stage parasite survives within the RBC for nearly a day following invasion. Given the essential nature of PfVP1 and its absence in humans, PfVP1 emerges as an ideal target for combating the ring stage parasites. Inhibiting this less active stage is of utmost importance to advance malaria control and eradication efforts.

NIH Research Projects · FY 2025 · 2024-06

PROJECT SUMMARY HIV infection is commonly co-occurring with drug use. Both HIV infection and drug use are associated with adrenal dysfunction and hormonal dysregulation, which can drive impairments in response to stress. Stress is a major factor affecting HIV disease outcomes and susceptibility to relapse, however there is a lack of understanding of the factors that promote relapse in people living with HIV. Responsivity to stress is regulated by the glucocorticoid, cortisol. HIV can result in enhanced basal cortisol levels, but reduced cortisol responses to stress. In contrast, cocaine dependence is associated with enhanced basal and stress-induced cortisol responses. However, the interaction of HIV infection and cocaine use on cortisol levels is not well characterized. In rodent models, cocaine exposure enhances the corticosterone response to stress in male and female rodents, while tat transgenic male, but not female, mice exhibit blunted corticosterone responses to stress. Thus, HIV- infected females may be more vulnerable to stress-induced reinstatement of cocaine seeking due to lack of blunted corticosterone responses by tat. Glucocorticoid signaling at astrocytes may be an important mediator of this response. The glucocorticoid receptor can be downregulated in response to stress, and this effect appears to be specific to astrocytes. Astrocytes are also important mediators of relapse-related behaviors and are independently regulated by cocaine and HIV infection. Further, modulation of glucocorticoid receptors regulates astrocytic calcium signaling, suggesting that stress modulates astrocytic activity. Our preliminary data indicate that stress-induced reinstatement of reward seeking is associated with enhanced astrocytic calcium signaling in the reward-paired context. Thus, astrocytic glucocorticoid signaling may be a potential regulator of the stress response and stress-induced relapse-like behavior in the context of HIV infection. Aim 1 will determine the effects of EcoHIV inoculation on stress-induced corticosterone levels and astrocytic glucocorticoid receptor expression following a history of cocaine exposure in male and female mice. Male and female mice will be inoculated with EcoHIV and undergo cocaine exposure and withdrawal, and then be subjected to forced swim stress. Serum corticosterone levels and immunofluorescent labeling of astrocytic GR will be assessed to determine if female mice exhibit enhanced stress responses following EcoHIV infection. Aim 2 will determine whether EcoHIV infection sex-specifically promotes stress-induced reinstatement of cocaine seeking. Male and female mice will be inoculated with EcoHIV and be trained in a conditioned place preference paradigm for cocaine, followed by extinction and reinstatement following forced swim stress exposure to determine if EcoHIV-infected female mice exhibit enhanced stress-induced reinstatement. The results of these experiments will identify a potential target for reducing stress-induced relapse in people living with HIV. Further, we will gain significant knowledge of sex- specific regulation of the glucocorticoid system by EcoHIV infection.

NIH Research Projects · FY 2026 · 2024-06

Abstract Maternal substance use (SU) is a significant and growing public health problem. In 2020, over 26 million U.S. women used illicit substances, and SU rates among women giving birth have nearly quadrupled in the last decade. Despite these realties, mothers with substance use disorders (SUDs) remain an underserved and understudied population. For Black mothers in the U.S., the lack of research on risk, protective factors, and effective elements of treatment for maternal SU is even more pronounced. For example, while a growing body of research demonstrates the negative effects of racism-related trauma on a wide-range of health outcomes, no quantitative studies, and only a handful of qualitative studies have examined the contributions of racism- related trauma to maternal SU outcomes in Black women. For Black U.S. mothers, their own experiences of racism-related trauma, and the parenting stress they can experience in worrying about and processing their children’s experiences with racism, likely significantly impact feelings of fear, helplessness, parenting competence, and parenting stress which can all contribute to maternal SU risk. While racism-related trauma likely contributes to Black mother’s SU risk, in part through amplifying parenting stress, the parenting role, and particularly the quality of mother-child relationships, may also serve as a critical SU protective factor. One factor that has been shown to bolster the quality of the parent-child relationship and improve maternal SU outcomes is maternal mentalizing, defined as the capacity and tendency for mothers to observe and make generally accurate inferences about thoughts, emotions and intentions of themselves and others, including their child, and how they affect behavior. Recent maternal SU intervention studies show that improving maternal mentalizing improved mother-child relationship quality, buffered against the effects of other/non- racism related trauma on SU, and improved SUD recovery outcomes. Thus, mentalizing is likely an important protective factor for maternal SU outcomes, but no studies have investigated if maternal mentalizing may serve as a protective factor against the effects of racism-related trauma for Black mothers struggling with SUDs. The objective of the proposed study is to collect and analyze cross-sectional and longitudinal data on experiences of racism-related trauma and maternal mentalizing in a unique sample of Black mothers with SUDs who are seeking treatment at Drexel University College of Medicine’s Caring Together Program (>80% of patients identify as Black/AA; 85% are mothers of dependent children). This research will contribute to NIDA’s research priorities to: 1) better understand the real-world complexities and the impact of important social factors on maternal SUDs; and 2) conduct research that will significantly impact the promotion of health equality in SU research and practice. Accomplishing the study aims will provide important data on SUD risk and protective factors for Black/AA mothers and be a first step towards a future RO1 submission aimed at developing culturally responsive evidence-based assessment tools and intervention strategies.

NIH Research Projects · FY 2026 · 2024-05

ABSTRACT Osteoarthritis (OA) is characterized by the irreversible breakdown of cartilage extracellular matrix (ECM). Current regenerative strategies cannot fully restore the biomechanical functions of cartilage, as they do not fully recapitulate the collagen fibrillar architecture of native ECM. This project will study the activities of the regulatory fibril-forming type III collagen (collagen III) in directing cartilage matrix assembly and chondrocyte mechanotransduction at different stages of post-natal growth, maintenance and disease. Our central hypothesis is that collagen III regulates cartilage ECM biomechanics and chondrocyte mechanotransduction through its effects on collagen fibril assembly and integrin switching, and that loss of collagen III increases cartilage susceptibility to OA. Specifically, we will elucidate the activities of collagen III in the formation and maintenance of cartilage (Aim 1), in injury-induced cartilage degradation in OA (Aim 2), as well as in the neo-matrix assembly and chondrocyte mechanotransduction (Aim 3). In Aim 1, we will determine if loss of collagen III impairs ECM fibril assembly, pericellular matrix (PCM) integrity, chondrocyte mechanosensing and gene expression during the post-natal growth and aging. In Aim 2, we will first determine if loss of collagen III accelerates cartilage degeneration and OA progression in post-traumatic OA induced by the following destabilization of the medial meniscus surgery (DMM model). We will then determine if collagen III delays the degradation of collagen II and aggrecan in response to inflammatory factors known to drive OA progression. In Aim 3, we will first determine if collagen III regulates the assembly of neo-matrix synthesized by chondrocytes cultured in 3D hydrogel under the stimulation of dynamic loading. Next, we will delineate the effects of collagen III on regulating the integrin switching of chondrocytes and downstream mechanosensitive pathways, with a focus on integrin α11. To elucidate the role of collagen III in cartilage, a number of innovative approaches will be used. We generated a novel inducible collagen III deficient (i.e., Col3a1F/+, Col3a1F/F) mouse model to study the dose-dependent effects of collagen III by temporal targeting of collagen III in cartilage. We will apply a multidisciplinary analysis paradigm that integrates atomic force microscopy (AFM)-nanomechanical tests, immunofluorescence imaging and laser capture microdissection. These techniques will enable us to study the impact of collagen III on cartilage composition, structure, mechanics and cell mechanotransduction, and to determine mechanisms by which it regulates matrix remodeling and mechanosensation. Successful completion of this study will establish collagen III as an essential constituent responsible for ECM structural integrity and cell mechanotransduction of cartilage. Outcomes will provide a new basis for improving cartilage tissue engineering using collagen III-based biomaterials and elucidate new collagen III-dependent mechanisms to serve as targets for OA intervention.

NIH Research Projects · FY 2026 · 2024-04

Abstract Neuronal function depends on the precise localization and release of neuromodulators, such as growth factors, in response to stimuli. Our lab recently identified an unexpected, but exciting role for ER stress sensor PERK, PKR-like ER kinase, in neuronal growth factor localization. Specifically, in the absence of PERK, a dendritic TGF-ß-like growth factor is mistargeted to the axons, while an axonal insulin-like-growth factor (IGF) is retained in the cell body. Interestingly, PERK is genetically linked to the tauopathies Alzheimer’s Disease (AD) and Progressive Supranuclear Palsy (PSP). At least two of the three genetic variants have decreased kinase activity, but it is unknown how decreased activity is a risk for disease. Impairment of PERK’s role in the correct localization of neuroprotective IGF and TGF-ß-like growth factors could provide a molecular connection to neurodegeneration. Because it is unclear how PERK may directly mediate growth factor localization, I asked whether PERK functions through one of its known downstream targets. Strikingly, I found that CaMKII, a kinase whose function is critical for neural plasticity and memory, is genetically downstream of PERK. Importantly, CaMKII has a known function in axonal targeting of neuropeptides, which has the potential to explain PERK’s novel role in growth factor localization. This proposal aims to define how PERK and CaMKII interact to control axonal-dendritic targeting of select neuroprotective growth factors. To do this, I will test whether PERK acts through its kinase activity, whether phosphorylation-dependent activation state of CaMKII affects growth factor localization, and whether PERK directly phosphorylates CaMKII. The proposed studies will be completed primarily at Drexel University under the guidance of the sponsor and co-sponsor; however, I will seek guidance from my collaborators at UPenn, especially for the advanced in vitro kinase assays to test whether PERK directly phosphorylates CaMKII proposed in Aim 2. Together with my sponsors, I have developed a comprehensive training plan that addresses training in hypothesis-driven research, scientific communication and writing, and career development, as well as augmenting my formal training in neuroscience. The overarching goal of this pre- doctoral fellowship project is to guide me in preparing for an independent career in biomedical research, focusing on the areas related to protein-based pathology in neurodegeneration.

NIH Research Projects · FY 2026 · 2024-04

ABSTRACT: Uveal melanoma (UM) is the most aggressive form of intraocular cancer in adults. Primary disease can be effectively treated however, ~50% of patients will develop metastasis. Unfortunately, metastatic lesions are often fatal within one year of diagnosis; making UM one of the most lethal cancers. Metastatic UM has strong liver tropism and are refractory to standard treatments. As there is a clear unmet clinical need for viable treatment options, the overarching goal of this application is to highlight novel therapeutic avenues to treat metastatic UM. Since most UM metastases are found in the liver and are responsible for poor prognosis, we seek to better understand how the liver microenvironment supports metastatic UM. In this proposal, we will use in vitro, ex vivo organotypic liver slice co-culturing, and in vivo experimental modalities to investigate: 1.) How UM liver metastases are susceptible to ferroptosis – a programed cell death pathway associated with the accumulation of toxic lipid peroxides. Publicly available datasets and our preliminary data demonstrate that loss of BAP1 – a strong determinant of liver metastases, is associated with ferroptotic resistance. Furthermore, we found that mutant BAP1 UM can better cope with stresses imposed by a lipid-rich microenvironment. Lastly, our preliminary data suggest mutant BAP1 UM are more sensitive to pharmacological inhibition of anti-ferroptotic machinery than wildtype BAP1 counterparts. 2.) Investigate how liver associated selenoproteome expression help UM stave off oxidative stress. The liver is the body’s selenium repository and many genes associated with ameliorating ferroptotic or oxidative stress are selenoproteins – proteins that have at least once selenium containing amino acid, selenocysteine. Preliminary in vitro and ex vivo liver slice experimentation demonstrate enhanced selenoproteome expression when UM cells are dosed with exogenous selenium compounds or liver conditioned media. These data are supported by transcriptomic expression patterns that indicate BAP1 loss (likely metastatic) is associated with increased genes that facilitate selenoprotein synthesis. 3.) Determine how targeting ferroptosis and the selenoproteome in UM liver metastases modulates the tumor immune microenvironment. Since ferroptosis is an immunogenic cell death pathway, we will use syngeneic systems to highlight how ferroptosis or reduced selenoproteome expression activate both innate and peripheral anti-UM immune responses. Specifically we will investigate how these stresses stimulate the phagocytic activity of hepatic macrophage-like cells including Kupffer cells. Moreover, we will use syngeneic in vivo modeling to test how pharmacological induction of ferroptosis or genetic based reduction of selenoproteome expression shapes the hepatic tumor immune microenvironment. By investigating the points highlighted above, we will gain mechanistic insights and highlight therapeutic vulnerabilities associated with the unique interplay between the liver microenvironment and UM metastases.

NIH Research Projects · FY 2025 · 2024-02

PROJECT SUMMARY The prevalence of autism spectrum disorder (ASD) in the United States is 1 in 44 in children, with more than 5 million adult Americans and about 1% (more than 75 million people) of the world population having ASD. ASD is characterized by four core symptoms, which are; impaired communication and social interaction, restrictive interests, repetitive behaviors, and irritability. Current medications are limited and focus only on irritability, which is just one of the four core symptoms. To relieve the severe burden of this disease, the development of novel medications that can address the full range of ASD behaviors is an urgent unmet need. Defects in neuronal morphogenesis, including neurite formation, spine formation and synaptogenesis, cause improper neural connectivity, which has been implicated in neurodevelopmental disorders, such as ASD, epilepsy, and mental retardation. Recent studies have shown that many ASD animal models and human models using induced pluripotent stem cells (iPSCs) show decreased neurite length. We have recently found that Pigment Epithelium- Derived Factor (PEDF) plays a critical role in neuronal morphogenesis and neural activity in vivo, including neurite formation, spine formation and calcium signaling. Preliminary data show that the treatment of primary cortical neurons with PEDF-derived snippet, called PEDF(44-mer) (amino acid 78-121) peptide accelerates neurite formation. Also, we found that PEDF(44-mer) could rescue social interaction defects in prenatal valproic acid (VPA)-exposed mice. In addition, our proteomic analysis revealed the activity-dependent neuroprotective protein (Adnp) is a potential downstream effector of PEDF signaling pathway. ADNP mutations in humans are among the most common single-gene causes of ASD and result in ADNP syndrome. We found that PEDF(44- mer) could rescue social interaction defects and repetitive behavior seen in the Adnp+/- mice. Therefore, in Aim 1, we will investigate whether treatment of the Adnp+/- mice with PEDF peptides can ameliorate the defects in neuronal morphogenesis, including neurite formation and spine formation. In Aim 2, we will test whether PEDF peptides can ameliorate the defects in synapse formation and neural connectivity seen in the Adnp+/- mice. Since our proposal will test a potential new medication target for the defects in early developmental stages seen in children with ADNP syndrome and ASD, our study makes a major contribution to a field that would benefit millions of people in the United States. We will scrutinize the possibility of a novel drug useful for treating the impairment of neuromorphogenesis and neural connectivity during early development, which are incurable with existing medications. Thus, the successful completion of the research will lead to the improvement of the quality of life of children and adults with ASD and neurodevelopmental disorders.

NIH Research Projects · FY 2026 · 2024-01

PROJECT SUMMARY More than 15 million older adults have difficulty carrying out self-care, household and/or mobility activities, referred to as a functional disability —with significant disparities by income. The experience of having a functional disability frequently results in high healthcare spending and lower quality of life. Furthermore, functional disability is associated with greater emotional, physical, and financial difficulties or burden in family caregivers who support older adults with everyday tasks. Home environments are recognized as a key factor in disability; however, the role of housing disrepair—including, for example, damage to one’s roof or walls, problems with heating or plumbing— has rarely been studied for how it may contribute to uneven rates of functional disability among low income older adults and impact caregiver well-being. Housing disrepair can be addressed, and therefore it is a potential target for interventions to improve function and slow disability among older adults, potentially reducing caregiver burden and narrowing disparities by income. The specific aims of this explanatory sequential mixed methods research study are to: 1) characterize housing disrepair among U.S. older adults and its associations with (a) functional disability among low income older adults, and (b) caregiving burden (emotional, physical, and financial); and 2) characterize experiences of daily functioning of low income older adults and their family caregivers in the presence of housing disrepair, and identify barriers to making home repairs and preferences for addressing disrepair. This study will generate foundational knowledge and an understanding of possible modifiable factors and mechanisms (NIH Stage Model 0) from which to develop an intervention. The candidate, Dr. Okoye, is an Assistant Professor at Drexel University’s College of Nursing & Health Professions and School of Public Health, with clinical experience as a nurse practitioner. With a rigorous training plan including methodological training in mixed methods research and intervention development and content expertise in family caregiving and research team leadership, and with strong, committed mentorship, Dr. Okoye will become a grant-funded independent investigator dedicated to improving health and well-being for older adults and their families. This project is well-aligned with the strategic objectives of the NIA to understand environmental factors that create and sustain health disparities among older adults, and reduce caregiver stress.

NIH Research Projects · FY 2025 · 2023-09

Reducing overdose mortality immediately and long-term is a top public health priority as the overdose epidemic in the U.S. continues to worsen. The COVID-19 pandemic, which began hitting the U.S. in early 2020, has exacerbated the overdose crisis. Opioid overdose deaths, which accounted for the most overdose deaths in 2020, continue to drive the epidemic. Overdose deaths linked to synthetic opioids, such as illicitly manufactured fentanyl, have increased significantly and comprised most of the opioid-related deaths in 2020. Despite increasing availability and acceptability of naloxone among laypersons, opioid overdose deaths remain catastrophically high in communities across the U.S. The UnityPhilly smartphone app was developed in 2018-19 alongside several community-based organizations as a public health intervention in response to the opioid overdose crisis in Philadelphia, which has the most acute overdose epidemic among large cities in the U.S. UnityPhilly automatically connects bystanders and victims of opioid overdose with nearby community members who can respond immediately with naloxone. The objective of this proposal, following a successful feasibility study (R34) and clear evidence of overdose reversal supported by UnityPhilly, is to create an easy-to-use, effective, sustainable, and scalable smartphone app to be deployed across the city of Philadelphia. This objective will be achieved by studying subgroups of people equipped with naloxone and UnityPhilly (n=450) and disseminating UnityPhilly to 3,000 citizen volunteers for everyday use to respond to opioid overdose emergencies. The long-term goal of this research is to create a scalable app that can be disseminated to communities across the U.S. experiencing high levels of opioid overdose death. The rationale for this study is that expanding the availability of the UnityPhilly app to laypersons citywide will increase the speed and delivery of naloxone to opioid overdose events across Philadelphia while laying the groundwork for scalability and broader national uptake. Our goals will be achieved with three specific aims: 1) Redevelop UnityPhilly to ensure ease of use; 2) Assess differences in the effectiveness of UnityPhilly across varied urban environments and participant profiles; and 3) Build and study a sustainable environment for UnityPhilly to expand city-wide. This 5-year study will have significant impact by providing actionable evidence regarding the effectiveness of an app-based naloxone intervention to scale up for nationwide use. The study will be conducted in partnership with long-standing community-based organizations to ensure usability and acceptability. This intervention is highly significant since it directly addresses one of the most significant public health problems in the U.S. – the opioid overdose epidemic – which is worsening due to the effects of COVID-19. This intervention is highly innovative as it improves upon a previous developed successful mobile phone app and expands its use to a broader population of users in a large city most impacted by the opioid crisis.

NIH Research Projects · FY 2024 · 2023-09

Project Summary Chronic pain and alcohol use disorders (AUD) are highly comorbid. People with chronic pain have an increased likelihood to develop AUD than those without. Further, chronic pain and high pain intensity are associated with elevated risk for relapse to alcohol use. Despite this, there is limited preclinical data on the neurobiological substrates underlying relapse in the context of chronic pain. People with chronic pain report using alcohol to alleviate pain and the accompanying psychosocial stress, which likely engages distinct neurocircuits to regulate reward seeking. Our previous data in the spared nerve injury model of chronic neuropathic pain demonstrate that ethanol effectively reduced allodynia – a hallmark symptom of chronic neuropathic pain – in both male and female mice. Our preliminary data further identified facilitated pain-induced reinstatement of ethanol seeking in a conditioned place preference model in males with chronic pain as compared to their sham injured counterparts. The prelimbic cortex (PL) – a subregion of the medial prefrontal cortex – is a common substrate in the regulation of ethanol seeking and pain. The PL and its outputs are key regulators of reinstatement of reward seeking, a model of relapse-related behavior. The PL also mediates both affective and cognitive components of chronic pain in rodent models and is highly disrupted in patients with chronic neuropathic pain. This makes the PL a promising target in investigation of ethanol seeking and reinstatement under conditions of chronic pain. Thus, experiments in this proposal will test the overarching hypothesis that chronic pain alters ethanol relapse- related behaviors and associated neurobiological substrates, with a focus on the PL and its subcortical projections. To test the hypothesis that chronic neuropathic pain alters PL activity during relapse-related behavior, Aim 1 will combine in vivo electrophysiology with behavioral analyses to investigate PL activity during the acquisition and expression of ethanol conditioned place preference and pain-induced reinstatement in adult male and female mice with a spared nerve injury. Further, as we have demonstrated that ethanol is antiallodynic in the spared nerve injury model, the effect of ethanol on PL activity surrounding painful stimulation will be characterized. Aim 2 will test the hypothesis that discrete PL projections regulate reinstatement of ethanol seeking. We will use chemogenetics to silence PL projections to the nucleus accumbens core or basolateral amygdala, with the expectation that projections to the basolateral amygdala are necessary for pain induced reinstatement but not ethanol-primed reinstatement in the context of chronic pain. Together, these experiments will provide insight into the unique neurobehavioral niche mediating ethanol seeking and relapse-related behavior under conditions of chronic pain. We expect that completion of this proposal will serve as a scaffold for subsequent research into the neurobiological substrates of ethanol seeking.

NIH Research Projects · FY 2025 · 2023-09

ABSTRACT The central theme of the Drexel ResearCh Center on Extreme Weather and Urban Health (CCUH) is the creation and dissemination/translation of evidence that will support urban policies to address the health impacts of extreme weather events in cities. Urban areas are especially vulnerable to the effects of extreme weather, but also present many opportunities for action. Research on the health impacts of extreme weather must span many different kinds of urban communities and must also consider differences in impacts across neighborhoods within cities. Based on the Urban Health Collaborative’s established collaborations and research portfolio on the factors that impact urban health we aim to build institutional capacity at Drexel and across our team to support action-oriented research on the impacts of extreme weather on population health and health disparities in cities. Specifically, we will leverage existing strengths at Drexel in urban health and health disparities, our research network on urban health across cities. This robust, existing infrastructure will enable us to expand our urban health and health disparities work to encompass the generation of solutions-oriented evidence on the impacts of extreme weather on health in cities and translate that evidence into actions in partnership with communities and policymakers. The Center will focus on extreme heat but will build the capacity needed to expand to other extreme weather events that impact urban areas (such as storms, floods and wildfires). Our aims are: (1) to create an organizational structure that promotes collaborative transdisciplinary and policy-relevant research on extreme weather and health in cities (Administrative Core); (2) to support capacity-strengthening for research on extreme weather health impacts in urban settings through structured training activities, funding pilot grants and research methods translation and support (Research Capacity Building Core); (2) to demonstrate the informativeness and policy-relevance of research on extreme weather and health disparities through a research project on intra-urban disparities (Research Project) and (4) to increase capacity for policy translation and policy impact through the engagement of policy makers and impacted urban communities in order to inform future research questions, as well as dissemination and translation efforts to maximize impact (Community Engagement Core.) Through these aims we will support the creation of the infrastructure, research and engagement capacity, and partnerships needed to expand policy relevant research on the impacts of extreme weather on health and health disparities in urban areas. Our ultimate goal is to become a center of excellence on extreme weather and urban health and meaningful engagement of policy makers and communities to maximize policy impact.

NIH Research Projects · FY 2026 · 2023-09

The Community-Led Research Coordinating Center (C3) will provide overall coordination and support for NIH-funded community-led research teams in order to maximize the quality, productivity, and impacts of their proposed intervention research. It will also develop and share resources relevant to developing research capacity in community-based organizations more broadly to support community-led interventions that improve population health. The C3 has three overarching goals (1) Facilitate interaction across organizations interested in community-led intervention research to enhance the quality and impact of community-led research and its relevance to improving population health in the US. (2) Support organizational research capacity building for community-led intervention research, and (3) Advance the science of community-led intervention research. The C3 will bring together expertise relevant to the development, implementation and evaluation of community-led interventions, develop and share research capacity-building resources for supporting effective interventions and community-based organization research infrastructure, and facilitate advancement of rigorous science to understand to what extent and how community-led interventions impact health in local communities.

NIH Research Projects · FY 2025 · 2023-09

PROJECT SUMMARY/ABSTRACT Pain is one of the most common and costly health problems worldwide. Due in part to the inadequacies of purely biomedical approaches, many people are increasingly seeking complementary approaches to pain man- agement, including music-based interventions (MBIs). Although the pain-relieving effects of MBIs are well-es- tablished, lack of understanding of MBIs' mechanisms of action prevents us from exploiting their full therapeu- tic potential. In order for mechanistic research on music and pain to progress in an efficient and rigorous man- ner, the building of a multidisciplinary research workforce capable of leading innovative mechanistic studies is needed. To this end, we propose to create the Music4Pain Network, a multidisciplinary research network that will bring together neuroscientists, music therapists, musicians, neuropsychologists, rehabilitation scientists, psychophysiologists, and more. The Music4Pain Network aims to accelerate knowledge in three key areas: (1) development of a taxonomy of key terms and definitions related to MBIs and music, (2) increased understand- ing of the mechanisms underlying the benefits of music for pain, and (3) identification of biomarkers and per- son variables that predict treatment response to MBIs. Network activities will be guided by a formal research agenda that will be developed by the Network's Core Investigator Team in collaboration with scientists with complementary expertise. The Music4Pain Network will forge new multidisciplinary research collaborations by (1) actively promoting the Network across disciplines to recruit experts with relevant and complimentary knowledge, (2) building an interactive Network website to enable identification of potential collaborators, shar- ing of resources, and featuring of Network activities and products, (3) promoting the Network using social me- dia platforms, and (4) organizing annual meetings, webinars, and Music and Pain Special Interest Groups. In addition, the Music4Pain Network will stimulate innovative, multidisciplinary mechanistic research through pilot funding. The pilot funding will support the collection of innovative data to strengthen independent research funding applications. The Network will also fund Visiting Scholar positions to help PhD students and postdoc- toral fellows gain skills and expertise related to Network goals. In addition, the Network will build the music and pain research workforce by mentoring new and early career investigators to develop research skills and sup- port their efforts in obtaining extramural funding. The work that will be made possible through the Music4Pain Network will enable the development of new, or optimization of existing, MBIs so that acute and chronic pain can be better managed with a low-cost, non-pharmacological approach that has wide appeal to a large number of people. Improved efficacy of MBIs and better understanding of their mechanisms of action will speed up their adoption in clinical care. This could have important consequences for the millions of Americans currently living with pain.

NIH Research Projects · FY 2024 · 2023-09

ABSTRACT Rhythm is a critical feature of locomotion and is generated by interneurons in the spinal cord. The intrinsic and local mechanisms employed by lumbar spinal rhythmogenic interneurons and how they are recruited by supraspinal locomotor centers represent major gaps in our understanding of rhythmogenesis and locomotor circuitry. This information is crucial in the pursuit of therapeutic targets to treat the leading causes of paralysis including spinal cord injury, traumatic brain injury, and Parkinson’s Disease. Spinal interneurons expressing the transcription factor Shox2 include a group of putatively rhythmogenic interneurons in the mouse. Shox2 interneurons in the adult lumbar spinal slice possess rhythmogenic ionic currents, including persistent inward currents, and make functional excitatory connections to other Shox2 interneurons. We have found that a subset of Shox2 interneurons in the adult lumbar spinal slice displays spontaneous rhythmic membrane potential oscillations. Intrinsic and local network properties are essential for the initiation and maintenance of rhythmic oscillations in other models of neuronal bursting and Shox2 interneurons in the spinal slice allow for the study of the specific mechanisms involved in the adult mammalian locomotor circuitry. This proposal explores how oscillations in Shox2 interneurons are generated and recruited using an innovative approach that combines whole cell patch clamp electrophysiology, transsynaptic tract tracing, and optogenetics. With this combinatorial approach, we will test the overarching hypothesis that Shox2 interneurons in the lumbar spinal cord of adult mice display rhythmic firing that is critically mediated by persistent sodium current and local excitatory synaptic connections and recruited by monosynaptic excitatory input from the lateral paragigantocellular nucleus in the brainstem. In whole-cell patch clamp experiments, we will identify the voltage sensitive current(s) and underlying voltage-gated ion channels critically involved in rhythmic oscillations in individual Shox2 interneurons. Additionally, we will pharmacologically test the contributions of the local synaptic connections to oscillatory properties in Shox2 INs in the lumbar spinal slice. Lastly, the supraspinal nuclei which monosynaptically project to lumbar Shox2 interneurons will be identified by monosynaptic restricted transsynaptic tracing from Shox2 interneurons in the adult mouse. These anatomical projections will be functionally evaluated optogenetically in the adult lumbar spinal slice. Together, this represents essential first steps in identifying and evaluating mechanisms of rhythm generation in and recruitment of Shox2 interneurons which may serve as therapeutic targets for the treatment of paralysis in which spinal locomotor circuits are left intact, but dormant.

NIH Research Projects · FY 2025 · 2023-09

Structural variants (SVs) are the largest source of variation in the human genome and are frequently associated with disease phenotypes. Thus, the comprehensive characterization of SVs is essential for understanding human genome structure and function, and the role of SVs in disease. While long read sequencing technologies improve the alignments to the human reference genome that are used for identifying SVs, current widely used SV calling methods are limited due to relying on alignment evidence, which is less reliable for larger SVs and in highly repetitive regions of the human genome. The goal of this proposal is to develop an improved computational method that integrates additional information, including copy number predictions based on coverage and single-nucleotide variant (SNV) allele frequencies, to improve sensitivity for a wider range of SVs. Additionally, I aim to improve SV detection by leveraging additional genomics technologies such as optical mapping. Finally, I aim to include support for the latest human pangenome reference representations, which should improve alignments and enable more comprehensive SV characterization. This proposal has important implications for identifying structural variants with disease relevance that have been understudied due to limitations in current approaches. I will also develop a machine-learning-based model to assign SV confidence scores based on alignment and genomic context evidence. Confidence scores will be used to filter likely false positives and improve precision. Finally, I will be incorporating support for pangenome graph alignments: Unlike conventional linear human reference genomes such as GRCh38, pangenomes can represent multiple complete haplotypes simultaneously in a single graph representation, which enables identification of structural variants for regions of the human genome that may be missing or incomplete in GRCh38. In summary, in this project I will develop a novel SV calling method capable of integrating evidence beyond alignments, as well as from multiple genomics technologies, to identify SVs in the human genome often missed by current methods. This method will have important implications for the identification and characterization of SVs with clinical relevance. Through this research training plan, I will 1) acquire advanced expertise in bioinformatics and human genomics, 2) refine my oral and written communication skills, and 3) establish a foundation for a scientific career dedicated to the study and dissemination of knowledge on human genome variation.

NIH Research Projects · FY 2025 · 2023-09

PROJECT SUMMARY Stress-related systems undergo a change during the transition to ethanol dependence, such that activation, which in a non-dependent state may leave unaffected or suppress intake, instead increases consumption. This effect reversal often coincides with an upregulation in receptor gene expression for stress-related neuropeptides; however, for the stress-related neuropeptide, pituitary adenylate cyclase-activating polypeptide (PACAP), the changes instead appear to occur via a specific increase in receptor variant expression. Our study focuses attention on the paraventricular nucleus of the thalamus (PVT), which has notably and selectively dense expression of the less ubiquitous PACAP peptide isoform, PACAP-27, where it is expressed in a subpopulation of glutamatergic neurons. In preliminary studies, we have found with a 20% ethanol intermittent access (IA) model of binge drinking, that effects of PACAP+ cell manipulation in the PVT can change based on drinking history. In PACAP-Cre mice drinking under the IA model for 6 weeks, Cre-dependent chemogenetic inhibition of PACAP+ cells stimulated ethanol drinking in low drinkers but instead inhibited intake in high drinkers. With preliminary evidence that these PACAP-27+ PVT neurons send dense projections to the nucleus accumbens (NAc), we have also found in rats, which drink lower levels of ethanol than mice, that those drinking under the IA model for 6 weeks respond to PACAP-27 injection into the NAc with a suppression of ethanol intake. Further, rats with a longer IA drinking history (10 weeks) show a specific increase in gene expression in the NAc of the HOP variant of the PACAP receptor (PAC1). We have confirmed with quantitative real-time (qRT-)PCR that the HOP and SHORT variants are present in the NAc of mice. Building on our preliminary and published data, we hypothesize that activation of PACAP-27+ cells that send afferents from the PVT to the NAc suppresses non- dependent, binge-like ethanol intake, but increases intake in a dependent state (Aim 1); and this shift in behavioral output occurs as the PACAP system becomes dysregulated resulting in a specific increase in PAC1 HOP receptor variant expression (Aim 2). To test this, Aim 1 investigates the effect of activation and inhibition of the PVT→NAc PACAP pathway on ethanol intake before and after dependence, by using PACAP-Cre mice and Cre-dependent excitatory and inhibitory DREADDs injected into the PVT paired with cannula guided microinjections of CNO into the NAc shell. To determine the involvement of PAC1 receptor variants in the NAc on ethanol intake, Aim 2 will measure PAC1 variant mRNA expression in the NAc of non-dependent and ethanol dependent mice and also use specific interfering (si)RNA to knock down the PAC1 receptor variants in the NAc of non-dependent and dependent mice. Together, these Aims will determine how the PACAP+ PVT→NAc pathway affects ethanol drinking across states and how PAC1 variant populations in the NAc are changed with the transition to dependence and, in turn, affect ethanol intake.

NIH Research Projects · FY 2026 · 2023-09

Without intervention, by the end of this century, extreme heat will cause tens of thousands of excess deaths, particularly from respiratory and cardiovascular causes. Beyond the impacts of short-duration heat events, such as heat waves, it is critical to understand the effects of chronic heat exposure, assessed where most heat-related deaths occur: indoors. Improving understanding of individual and neighborhood characteristics that heighten or reduce heat vulnerability is also crucial, for informing the design of effective heat adaptation strategies. Yet, current knowledge of heat-related mortality and vulnerability remains limited in at least three ways. First, most research on heat-related death has quantified associations between short-term temperature spikes and acute mortality outcomes, leaving uncertainty about the total mortality burden of chronic heat exposure. Second, most research has calculated associations with outdoor rather than indoor temperatures, thus potentially under-estimating the mortality impacts of heat and leaving critical gaps in knowledge about safe maximum indoor temperature thresholds. Third, little is known about the extent to which housing interventions that promote thermal comfort and conserve energy, such as improving insulation or altering roofing material, may prevent excess deaths from chronic indoor heat exposure. There is an urgent need to fill these gaps since most people, and especially heat vulnerable subpopulations including individuals over age 65, spend the majority of their time indoors. We propose the first ever population-based, nationally representative, quasi-experimental, longitudinal cohort study of the effects of chronic indoor heat exposure on mortality in the United States. We will use data on age 65 and older adult participants of the MDAC study linked with Medicare and National Death Index data. This remarkably rich data set, which contains follow up on individuals for up to eight years, will be combined with indoor temperature and humidity variables calculated using rigorous, extensively validated, physics-based simulation models; individual-level housing characteristics; and high-resolution land cover data. To improve understanding of associations between the housing environment, chronic indoor heat exposures and mortality, and person- and neighborhood-level determinants of heat vulnerability, we pursue three aims. In Aim 1, we quantify associations between chronic indoor heat exposures and all-cause and cause-specific mortality, and identify temperature-zone specific, safe upper thresholds for hot-season indoor temperatures. In Aim 2, we elucidate person- and neighborhood-level factors that enhance or reduce vulnerability to chronic indoor heat exposure. In Aim 3, we quantify the total excess deaths that may be prevented through housing interventions that improve thermal comfort, under different temperature distributions. This impactful project will provide information that is critically needed to guide interventions to support health protection when it is hot. .