Icahn School Of Medicine At Mount Sinai

NIH Research Projects · FY 2025 · 2023-09

SUMMARY Glioblastoma (GBM) remains deadly. A major reason is a highly infiltrative GBM border, making complete surgical resection unattainable. Residual tumor cells inevitably spawn recurrent GBM, typically within 2-3 cm of resection cavity. Understanding GBM margins is thus critical to curb GBM invasion and relapse. Tumor- associated myeloid cells (TAMs) are the most abundant stromal cells in GBM, and they promote GBM expansion and infiltration through immunosuppressive properties, secretion of tumor-promoting factors (gliomagens), and preparation of invasion tracks. Previous research has largely focused on bone-marrow derived macrophages (MDMs), which reside mostly in GBM interior, less is defined for microglia (MG), resident innate immune cells in the brain that preferentially congregate at GBM margins. The current proposal intends to fill this gap by testing the central hypothesis that perturbing the supportive niche provided by margin-MG may help slow down GBM invasion and relapse. The premise of the approach rests on our compelling preliminary data establishing MG as one of the most abundant immune cell populations at GBM borders. Furthermore, our pilot study demonstrated that targeting MG proliferation (via IL-1/IL1R1 signaling) or MG motility/alignment (via axon guidance receptor Plexin-B2) resulted in significant reduction of GBM growth and invasion. However, major knowledge gaps remain: i) what are the signaling networks driving the persistence of tumor-promoting phenotypes of margin-MG, ii) does genetic make-up of the tumor play a role in dictating the immune landscape at GBM margin, iii) what is the nature of MG-derived gliomagens, iv) can we find a way to target margin-MG interactions with GBM cells, and v) how does chemoradiation therapy alter gene signatures and tumor-promoting gliomagens of margin-MG? To address these questions, in Aim 1, we will map the immune contexture and crosstalk with tumor cells at GBM margins using multiplex immunostaining, advanced spectral flow cytometry, single cell transcriptomics, and spatial multiomics. Genetically engineered mouse models (GEMMs) of GBM with defined driver mutations and human GBM tissues of matching subtypes will be used. We will identify distinct margin-MG populations and pro- tumorigenic signals originating from margin-MG. We will also conduct co-cultures and ex vivo organotypic brain slice studies for validation. In Aim 2, we will study the functional significance of margin-MG in promoting GBM expansion and invasion by examining the efficacy of targeting MG proliferation (via IL-1/IL1R1 signaling), MG motility/alignment (via Plexin-B2 signaling), or both, using genetic and pharmacological approaches in GEMMs of GBM. This will provide proof-of-principle that targeting key signaling pathways with different mechanisms of action may achieve synergistic effects for perturbing the supportive niche provided by MG at invasive margins. In Aim 3, we will examine the impact of chemoradiation on margin-GBM profiles, gliomagens, and functional significance in GBM recurrence. The new knowledge will help leveraging the signaling networks underlying intrinsic functions of tumor-promoting resident innate immune cells in order to curb GBM invasion and relapse.

NIH Research Projects · FY 2025 · 2023-09

In this project, the investigators propose to study the allosteric mechanisms that regulate lysine degradation and gain novel pathophysiological insights into the rare orphan disease glutaric aciduria type 1 (GA1). GA1 is an autosomal recessive inborn error of lysine, hydroxylysine and tryptophan degradation. Patients can present with brain atrophy and macrocephaly and may develop dystonia after acute encephalopathic crises that lead to striatal degeneration. The disorder is caused by a deficiency of glutaryl-CoA dehydrogenase (GCDH), which leads to the accumulation of neurotoxic glutaric acid and 3-hydroxyglutaric acid. GA1 is considered a treatable disorder and therefore included in newborn screening programs in many countries. However, current treatment consists of dietary intervention, carnitine supplementation, and emergency treatment which requires intense efforts from both caregiver, patient and clinical team. It must be meticulously maintained, but in 25% of patients neurological disease still develops. Thus, GA1 treatment needs further improvement, but development of new therapies is hampered by limited understanding of pathophysiological mechanisms. In human patients and the GA1 mouse model, symptomatic disease is accompanied by a striking increase in neurotoxic glutaric- and 3-hydroxyglutaric acid accumulation. The investigators hypothesize that the accumulation of toxic metabolites in GA1 due to the deficiency of GCDH is controlled by allosteric regulation of the lysine degradation pathway. In a high throughput screen, they have identified small molecule inhibitors and activators of the lysine-2-oxoglutarate reductase domain (LOR) of 2-aminoadipic semialdehyde synthase (AASS). This led to the discovery of a remarkable potential for allosteric regulation of this key enzyme in lysine degradation. Structural studies revealed two novel allosteric sites in LOR, one able to bind inhibitors, the other binding activators. Therefore the overall objective of this proposal is to understand the allosteric regulation of lysine degradation. In AIM 1, the structural and biochemical mechanisms of allosteric regulation of LOR/AASS will be studied using X-ray crystallography of LOR/AASS in complex with allosteric activators/inhibitors and enzymology. In AIM 2, the biological significance of allosteric regulation of LOR/AASS and its role in determining lysine degradation flux will be studied. The investigators will identify endogenous inhibitors and activators of LOR/AASS, and define the native protein interaction network of AASS. This knowledge will be used to define how this allosteric mechanism controls lysine degradation and contributes to metabolite accumulation in a GA1 cell line model. In AIM 3, neutral activators of LOR/AASS will be developed using a combination of medicinal chemistry and structure-based drug design. The ultimate goal of this project is to better understand the pathophysiology of GA1 and provide new treatment options.

NIH Research Projects · FY 2025 · 2023-09

(30 Lines) Modified Grant Title: INSPIRE: INterventionS for Promoting kIdney tRansplant Empowerment Kidney transplantation (KTx) is the preferred treatment for patients with end-stage kidney disease. Despite recent changes to the kidney allocation system some individuals are less likely to receive a KTx evaluation, a multi-step process requiring patient referral, patient medical/surgical/psychosocial evaluation, and patient waitlisting. As there are no standardized acceptable metrics for psychosocial evaluations, each of the steps is impacted by provider subjectivity and by multiple barriers that impede the completion of the KTx evaluation process leading to a fraction of patients with end-stage kidney disease listed for a KTx. We have identified barriers and facilitators to the evaluation and waitlisting for KTx including the lack of standardized evaluation criteria and patient barriers such as lack of support and financial concerns. To address these gaps, we propose a multi-level intervention in full partnership with an Executive Stakeholder Board and Workgroups comprised of patients, clinicians, caregivers, and system leaders for dialysis organizations and transplant centers. This work will be built on 2 decades of community-engaged research and trials to improve health in various patient populations. We will work with the Board to develop an intervention based on past work by our team and others, supplemented by formative interview with patients, caregivers, and clinicians. To increase rates of patients receiving KTx evaluation, community health workers who have a personal history of kidney disease will guide patients through the transplant evaluation process. This will include conducting a needs screen and addressing barriers uncovered, including facilitating appointments to address unmet needs such as food insecurity and transportation, control of symptoms and mental health challenges. To increase rates of waitlisting among those evaluated, we will identify subjective language from KTx providers notes and provide education on processes to ensure standardized and objective evaluations for nephrologists. We will evaluate the impact of this multifactorial intervention in a clinical trial among 336 adults with an eGFR <20 ml/min/1.73m2 or on in-center hemodialysis with a primary outcome of transplant waitlisting evaluation completion. Together, we will also develop a blueprint of how to conduct this work, so that it can be used nationally to improve KTx waitlisting and inform policies, systems and practices.

NIH Research Projects · FY 2024 · 2023-09

Project Summary Alzheimer’s disease (AD) is a devastating neurodegenerative disorder, affecting approximately 6 million adults in the United States, for which there is no cure or treatments which effectively slow progression of the disease. Genome-wide association studies (GWAS) have illuminated 75 loci associated with AD, but the causal variants underlying the disease-associations remain to be identified, along with the genes or pathways through which they act to regulate higher-order phenotypes. The integration of genomics with transcriptomics can inform the influence of common genetic variation on molecular phenotypes consequential to cellular function. My lab has shown that AD susceptibility loci are enriched for genetic variants which alter RNA levels and/or splicing, and these variants often lie in cis-regulatory elements enriched in myeloid cells. However, causal variants or genes remain elusive for most loci associated with AD. This proposal will contribute a valuable resource for research seeking to describe causal variants at GWAS risk loci and connect them to altered cellular function. Intricate pre- and post-transcriptional processing of awards vast functional diversity to RNA molecules, and among the most abundant post-transcriptional modifications is adenosine-to-inosine (A-to-I) RNA editing. In protein-coding regions, these base-specific changes “recode” amino acid sequences, and in non-coding regions, A-to-I editing fine-tunes genes by influencing the splicing, stability, and subcellular localization of RNA transcripts, along with their ability to bind micro-RNAs (miRNAs). Disrupted RNA editing activity has been widely reported in AD patients, but whether this is a consequence of the disease, or cause is not clear. This proposal will address the contributions of RNA editing to AD pathophysiology by testing the hypothesis that AD-associated genetic variants modulate A-to-I editing. I will use quantitative trait loci (QTL) mapping to relate common genetic variation to level of RNA editing at A-to-I events genome-wide in the brain and myeloid cells. Then, I will apply advanced statistical approaches to determine whether the genetic regulators of A-to-I editing reside in GWAS risk loci for AD. Importantly, I will implement appropriate methodology probing mediation, to parse bona fide causal gene regulatory pathways apart from pleiotropy or spurious effects of genetic associations. By prioritizing A-to-I editing sites which are subject to tight genetic regulation and resolving the molecular and cellular processes they help to orchestrate, the results from this work lay critical foundation for follow-up functional studies which can harness the power of RNA based therapeutics to develop treatments for AD.

NIH Research Projects · FY 2025 · 2023-09

Project Summary/Abstract. The suppression of melatonin production by nighttime retinal light exposure has been linked to health risks to nightshift workers. Blue-blocking filters can preserve nighttime melatonin levels, and monocular light exposures can radically reduce nighttime melatonin suppression to as little as 10% of that observed for conventional binocular exposures. Our premise is that positioning a blue-blocking orange filter over one eye will preserve binocular vision while reducing light-induced melatonin suppression relative to a completely unfiltered viewing condition. This solution should not impede the performance of visual tasks that might require binocular vision, nor should it cause user discomfort. We propose a laboratory experiment (Aim 1) to determine whether blue- blocking filters and monocular viewing, alone or in combination, are effective for maintaining melatonin at night without affecting visual performance and subjective sleepiness (KSS). Aim 2 will be conducted at the Simulation Teaching and Research Center (STAR) at the Icahn School of Medicine at Mount Sinai to determine whether altered viewing interventions could influence melatonin levels and simulated task performance requiring depth perception (e.g., catheter / intra venous insertion in dummy) in healthcare workers. For Aim 3, involving nightshift working workers operating in actual hospital environments at Mount Sinai Hospital and Memorial Hospital in South Bend, IN, we will determine whether eyewear aimed at maintaining melatonin at night would be effective, practical, and socially acceptable. Aim 1 will employ a crossover within-subjects design, exposing subjects to 6 experimental conditions (monocular/binocular x filtered/non-filtered, 2 controls) over the course of 6 independent sessions. Aim 2 will employ a within-subjects design exposing subjects to 4 experimental conditions (control, filtered binocular, filtered monocular, unfiltered monocular/dominant eye occluded) over the course of 4 nightshifts (separated by at least a week). Aim 3 will be employ a within-subjects design similar to Aim 2 over the course of 4 one-week sessions (at least 3 shifts per session) with salivary melatonin levels, sleepiness scores, and Likert scale responses, as the output measures. This proposal is significant from a practical perspective because the methods to be tested could serve as elegant, inexpensive, personalized, non-invasive optical interventions to protect the natural synthesis of melatonin in night-shift workers. We will be addressing Healthy Work Design and Well-being (cross-sector). As part of the Research to Practice (r2p) activity, we will address need to maintain melatonin at night among nightshift nurses with a novel, but inexpensive technology, and evaluate its efficacy in practice.

NIH Research Projects · FY 2024 · 2023-09

Project Summary Chronic psychosocial stress is a major risk factor for functional gastrointestinal disorders, such as irritable bowel syndrome (IBS). Notably, there is high co-morbidity between IBS and stress-related psychiatric disorders such as major depressive disorder (MDD), with IBS and MDD representing two of the most prevalent and debilitating illnesses worldwide. Potentially underlying this co-morbidity is the recent finding that chronic stress elicits low-grade inflammation, which has been associated with both IBS and MDD. Moreover, increasing evidence suggests that the gut-brain axis, or connections between the central and enteric nervous systems, contributes to the etiology of IBS. However, the mechanisms through which an emotional state such as chronic stress influences gut pathophysiology, including inflammation, remain poorly understood. In preliminary experiments using the chronic social defeat stress (CSDS) model in mice, we find that intestinal inflammation and barrier permeability become elevated following CSDS in both male and female mice, and these phenomena correlate with depression-like behaviors such as social avoidance. In this project, I will investigate how psychosocial stress causes this gut pathophysiology. Using retrograde viral tracing strategies from the gut to the brain, and whole-brain imaging, I have generated a list of candidate stress-activated brain regions that directly innervate the gut. In the first aim of this proposal, I will use integrated neuroscience and immunology techniques, such as chemogenetics and flow cytometry, to determine if activation of these brain regions can trigger gut inflammation and barrier permeability. Moreover, I aim to identify subsets of enteric neurons in the intestine that receive signals from the brain during stress to propagate IBS-like symptoms. In the second aim, I will then assess how inflammatory signals in the gut are conveyed to the brain to influence stress-relevant behaviors. As the brain can detect the inflammatory state of peripheral tissues through sensory afferent nerves, I will first identify which stress-responsive brain regions receive input from gut. I will then use fiber photometry to evaluate how gut inflammation modulates neuronal activity in these brain regions and its consequences on behavior. In parallel, I will investigate if a compromised intestinal barrier allows bacterial toxin translocation from the gut lumen into circulation to promote systemic inflammation and depression-like behaviors. Collectively, this project aims to define bi-directional stress-activated gut-brain circuits that contribute to IBS- and MDD-related symptoms.

NIH Research Projects · FY 2025 · 2023-09

Project Summary Chronic stress exposure increases vulnerability to a variety of mental illnesses including depression. However, not all individuals that experience stress develop depression. Furthermore, the mechanisms that lead to stress -resilience, the ability to avoid the negative social, physiological, and biological consequences of stress have yet to be identified. Here, we focus on understanding the transcriptional mechanisms of resilience to identify genes that may be protective against stress-related disorders to guide drug discovery efforts. The chronic social defeat stress (CSDS) paradigm in mice has proven to be a highly useful animal model for studying depression- related behavioral abnormalities. Following CSDS, a subset of mice exhibit depressive-like behavior and changes in gene expression that recapitulate changes seen in depression patients examined postmortem. Importantly, this paradigm allows for the distinction of animals that succumb to the effects of the stress, termed susceptible, from those that do not, termed resilient. Previously published work has identified a gene network in the Nucleus Accumbens (NAc) that is specific to resilient mice. In this proposal, I will establish a reproducible pipeline to characterize the regulatory dynamics of resilient-specific gene networks in order to better understand the transcriptional circuitry that exist within these networks. I will then activate these transcriptional circuits in stress-naïve mice before subjecting them to CSDS to test their influence on resilience. The proposed research will provide a framework to study the transcriptional mechanism(s) of resilience by providing mechanistic insight into the transcriptional circuitry regulating stress resilience in mice. Together these aims will, for the first time, establish a novel experimental approach for studying the control over resilience by a complex network of genes as opposed to standard approaches which interrogate one gene at a time. This approach is designed to be applicable to any brain region, animal model, or network-based bioinformatics approach.

NIH Research Projects · FY 2025 · 2023-09

PROJECT SUMMARY Guidelines for anti-seizure medications in older adult populations are incomplete or non-existent, even though the risk of recurrent unprovoked seizures (epilepsy) in adults peaks at 80 years old. As a group, anti- seizure medications are generally thought to be equally efficacious and medication choice should be informed by the secondary effects of these drugs. Older adults are likely to be particularly vulnerable to cognitive adverse effects because they may have lower cognitive reserve, undetected/undiagnosed neurodegeneration, competing cognitive impairing disorders, and often take other CNS-active drugs. Despite the increased risk and abundance of new prescriptions in older adults, most evaluation of the safety and effects of anti-seizure medications on cognition have been done in short-term studies in younger cohorts. No anti-seizure medication prescribing guidelines exist for older adults with mild cognitive impairment (MCI) or Alzheimer’s Disease and related dementias (ADRD). Currently, little information exists regarding anti-seizure medication use including: whether and how drug titration occurs, therapeutic drug monitoring, or how use may differ in older adults with dementia. In order to improve care, we must understand how and why particular anti-seizure medications are prescribed. We currently have limited understanding of how prescribers make decisions, including weighing any possible cognitive adverse effects, when adding and removing anti-seizure medications in older adults. These knowledge gaps are barriers to developing safe, effective and evidence-based treatment strategies. This study will use a large representative study of older adults (the Health and Retirement Study linked to Medicare data) to (1) understand differences in current use, titration, continuation, and laboratory monitoring of anti-seizure medications in older adults with seizures, with and without ADRD, (2) examine the comparative effect of commonly prescribed anti-seizure medications on cognitive decline and incident dementia, and (3) recruit a national sample of prescribers (e.g. primary care, internal medicine, geriatrics, emergency medicine, neurology) to understand decision-making in the context of anti-seizure medication prescription in older adults. My long-term goal is to develop an independent program focused on health services research to improve the care for older adults with seizure and dementia. The completion of this project will lay the foundation for a career of translating best evidence into practice. This project will form the backbone of an integrated training plan that will refine my existing pharmacoepidemiologic and biostatistical skills. Further, it will allow me to develop new knowledge in qualitative methods, geriatrics and cognitive decline. The training plan, focused mentorship and proposed project will allow me to learn, develop and apply the skills necessary for a successful transition to become an independent health services and outcomes researcher, and lay the groundwork for a trial of a multimodality intervention to improve prescribing in older adults with seizure, cognitive impairment and dementia.

NIH Research Projects · FY 2025 · 2023-09

Chronic intestinal failure (CIF) is a devastating condition where individuals are unable to eat and drink enough to meet basic survival needs. Patients with CIF are dependent on parenteral nutrition (PN) delivered intravenously by a pump via an indwelling central venous catheter. While PN is lifesaving, life-threatening complications can cause considerable morbidity, impair quality of life (QOL) and carry significant mortality risk. Care of patients with CIF is very complex and best delivered by experienced multi-disciplinary teams working in intestinal rehabilitation programs (IRP). Our recent work has shown a critical lack of expertise in CIF among US gastroenterologists and over half the states in the US do not have IRP. This lack of widely available expertise results in significant healthcare disparities for patients with CIF. Our recent work has shown that use of technology to disseminate knowledge through the LIFT-ECHO Project, based on the well-established ECHO Model can fill a critical gap in CIF care. Application of LIFT-ECHO to improve CIF patient care requires a systematic dissemination and evaluation approach, engaging multiple key stakeholders. We will test the hypothesis that clinical outcomes in patients with CIF will improve by providing virtual multi- D support to non-expert physicians through an online learning model, the LIFT-ECHO Project. Through intensive stakeholder engagement, we can disseminate and establish LIFT-ECHO to improve clinical outcomes in CIF nationally. AIM 1: To develop and validate an intestinal failure disease activity index (IF-DAI) that assesses current clinical status in CIF patients and is sensitive to short-term and medium-term changes. AIM 2: To demonstrate improved clinical outcomes and CIF/PN specific patient-reported quality of life (PRQOL) in CIF patients by providing virtual multi-disciplinary support to their physicians through LIFT-ECHO. AIM 3: (a) We will undertake a pragmatic formative process evaluation of LIFT-ECHO in its current state. (b) To disseminate process evaluation results of LIFT-ECHO nationally and evaluate dissemination effectiveness. Our study is the first application of the ECHO Model™ to a rare disease like CIF – our dissemination strategy will provide a comprehensive evaluation framework and a toolkit for assessment of ECHO™ implementation in the context of a rare disease. Our application targets the SEN: NOT-HS-21-014 to develop and implement LIFT-ECHO to address the disparities in access to expert care for patients with a chronic disease.

NIH Research Projects · FY 2024 · 2023-09

Project Summary: Age-related disorders such as Alzheimer’s disease (AD) present urgent issues to the aging population. Given the lack of universally effective treatments, novel approaches must be developed to reduce the impact of aging, the greatest risk factor for development of AD. Recent work has shown rejuvenation of age- sensitive organs, including the brain, through exposure to young blood. Our lab identified a loss of tissue inhibitor of metalloproteinase 2 (TIMP2) expression with age, and its restoration is critical in mediating the rejuvenating effects of young blood in aged animals. Despite these findings, the precise mechanism and cellular targets of TIMP2 have yet to be identified. It is currently unknown whether the positive effects of TIMP2 in aging generalize to the context of AD pathology. However, aging and AD present similar environmental challenges to the brain (e.g., inflammation, cellular debris from dying cells, toxic proteins). Based on the role of microglia in rapidly responding to debris (e.g., dying cells, amyloid, etc), we hypothesize that TIMP2 modulates microglial function. Consistent with this hypothesis, we have found that treatment with TIMP2 reduces microglial activation in the aged brain. Upon exposure to the debris of aging and AD, a subset of microglia acquires a disease- associated microglia (DAM) phenotype to respond to these challenges. This phenotype is initially protective by allowing microglia to effectively respond to environmental challenges, but unbridled activation can cause dysfunction or senescence of microglia and damage to surrounding tissue. Restoration of an effective response to debris may be critical to limit pathology. TIMP2 has been found to be a marker of the DAM transcriptional profile, and our preliminary data indicate that cell-intrinsic TIMP2 can regulate microglial state. This proposal aims to characterize microglial response to TIMP2 treatment and the cell-intrinsic role of microglial TIMP2 in enabling an effective response to debris in differing pathological contexts. Aim 1 will assess the morphological and inflammatory responses of microglia following treatment with TIMP2 in aged and AD pathological contexts to determine how microglia respond to damage following treatment. Furthermore, we will examine microglial- neuronal interactions in hippocampus using super-resolution microscopy and RNAscope. To probe the cell- intrinsic role of microglial TIMP2, Aim 2 will test the hypothesis that microglial TIMP2 rejuvenates response to aging and AD-associated pathology. We developed a mouse model that allows us to conditionally delete TIMP2 within microglia in diverse contexts. Upon deletion, we will examine response to debris by analyzing changes in pathology, morphology, cytokine release, and microglia-neuron interactions. The innovative methods employed in this proposal will provide insights into the role of TIMP2 acting as an extracellular protein on the function of microglia, while also probing cell-intrinsic effects of its activity in the context of debris associated with aging and AD. Characterization of the neuroimmune response to debris in different pathological conditions may facilitate development of therapies that slow down the aging process to limit onset of neurodegenerative diseases.

NIH Research Projects · FY 2025 · 2023-09

Project Summary The liver is responsible for maintaining blood glucose homeostasis. It is able to deposit large amounts of glucose in the form of glycogen and release glucose rapidly from its glycogen storage when needed. The hepatic glycogen metabolism maybe altered in diseases such as glycogen storage disorders, diabetes mellitus, and liver cirrhosis. Liver biopsy allows direct quantification of glycogen concentration, but it is highly invasive and cannot easily be repeated. 13C nuclear magnetic resonance (NMR) spectroscopy provides a non-invasive way to detect glycogen in the liver, but it is not clinically feasible due to the requirement of specialized imaging hardware. Recently, we have discovered a new contrast mechanism that allows the detection of glycogen based on its nuclear Overhauser enhancement (GlycoNOE). This method enables us to detect glycogen in vivo using standard MRI hardware. In our initial mice study, we found a linear relationship between glycoNOE signal and glycogen concentration and demonstrated that the change in liver glycogen could be measured dynamically. In this project, we aim to develop a new imaging technique to utilize this contrast mechanism in the human liver. To achieve this we will (1) develop and optimize a fast, 3D free-breathing, fat-water separated imaging approach that is suitable for glycoNOE detection in the human liver; (2) compare the NOE signal measured at fed and fasting state to validate that the change in signal reflects the change in glycogen content; and (3) dynamically measure the change of glycogen upon glucagon injection, which further validates the glycoNOE signal and also measures the rate of glycogen degradation. The new imaging technology will be applicable to brain and body imaging based on the nuclear Overhauser enhancement / chemical exchange processes. By providing a non-invasive, real time measure of the change in glycogen level in the liver, it will be possible to study glycogen metabolism in health and in diseases such as diabetes mellitus, glycogen storage diseases, and other liver conditions.

NIH Research Projects · FY 2025 · 2023-09

Project Summary: Calcium channel dysfunction in heart muscle cells induces cardiac arrhythmias such as Timothy syndrome, a severe form of genetic long QT syndrome type 8. In preliminary experiments using pharmaceutical approach, we found that activation of Sigma 1 receptor using its agonists could alleviate the cellular phenotypes in human induced pluripotent stem cell (iPSC) and mouse models of the genetic disease. The goal of this study is to design, synthesize and characterize new small molecules to develop novel Sigma 1 receptor agonists that are more suitable for the cardiac phenotypes in the genetic disease. To accomplish this goal, we will take advantage of our experience and expertise in pharmaceutical science and medicinal chemistry using human iPSC and rodent models to address our hypotheses. In addition, we will examine whether our approach using the new small molecules can be applicable for common forms of genetic long QT syndrome such as type 1 and 2. Therefore, our translational study will provide new opportunity of drug development for genetic cardiac arrhythmias.

NIH Research Projects · FY 2025 · 2023-09

Project Summary Pathologically altered affective learning is central to accounts of nearly every psychiatric disorder including depression and anxiety disorders. In humans, non-human primates, and rodents accurately learning which stimuli in our environment predict rewards or punishments is dependent on parts of frontal cortex, striatum, and limbic system, such as amygdala. A considerable amount is known about the neural mechanisms that are associated with adaptive patterns of learning within the circuits connecting these areas. What happens to these patterns of neural activity and the specific pathways involved when learning is enhanced or diminished by psychological processes is much less clear. Obtaining this knowledge is important as it would begin to reveal the specific mechanisms through which learning can be altered, information that is essential for identifying biomarkers in and aiding therapies for individuals with pathologically altered learning. Consequently, our aim here is to begin to establish how bottom-up and top-down processes impact stimulus-reward learning at the level of single neurons and circuit-level interactions. We specifically focus on the ventrolateral prefrontal cortex (PFC) and amygdala as prior work in macaque monkeys has shown that these areas, as opposed to other parts of frontal cortex and striatum, are required for efficient probabilistic stimulus-reward learning. These two areas are also reciprocally connected and, based on neuroimaging investigations functionally interact during learning further suggesting that they form part of a functional circuit essential for stimulus-reward learning. Our hypothesis is that bottom-up and top-down influences on learning impact neural activity within and communication between ventrolateral PFC and the basolateral nucleus of the amygdala but that bottom-up and top-down learning do so through different mechanisms and pathways. We will test our hypothesis by recording activity in ventrolateral PFC and basolateral amygdala as well as interconnected parts of orbital PFC and striatum in macaques learning in a probabilistic stimulus-reward task. We will assess functional interaction between areas using recurrent neural network models and measures of coherence when learning is altered by either bottom-up (aim 1) or top-down (aim 2) processes. To test the causal role of pathways linking amygdala and ventrolateral PFC we will also use chemogenetic approaches to selectively inhibit activity in these circuits. Thus, using an innovative combination of behavioral tasks, neural recordings, chemogenetic neuromodulation, and computational approaches we will establish the patterns of neural activity within and causal importance of PFC-amygdala pathways to bottom-up and top-down influences on learning. Completing these experiments will shed light on the specific neural mechanisms and pathways associated with altered learning, information essential for determining the processes that go awry in psychiatric disorders.

NIH Research Projects · FY 2025 · 2023-09

Project Summary/Abstract This proposes a comprehensive 5-year physician scientist career development plan for Dr. Stephanie Tankou. Dr. Tankou completed her postdoctoral fellowship training in Multiple Sclerosis at the Brigham and Women’s Hospital. During her fellowship years, she was involved in several preclinical and clinical studies investigating the role of the gut microbiome in multiple sclerosis (MS) and its mouse model experimental autoimmune encephalomyelitis (EAE). Since joining Mount Sinai as a tenure track faculty, she has been conducting several studies to investigate the effect of vancomycin on neuroinflammation in EAE mice. Studies from her laboratory revealed that vancomycin is a potent modulator of the gut-brain axis and they also identified 50 gut commensals that regulate neuroinflammation in EAE mice. This work has been recently accepted for publication in Microbiome and Dr. Tankou is the corresponding and senior author. The application builds on Dr. Tankou’s preliminary data supporting a key role for butyrate-producing bacteria in regulating astrocyte function and is structured to transition Dr. Tankou from trainee to fully independent investigator by leveraging intellectual and material resources at the Icahn School of Medicine at Mount Sinai. Dr. Scott Russo has mentored successful trainees and will guide Dr. Tankou throughout her training. Dr. Russo is an established investigator and recognized leader in blood brain barrier permeability in the context of neuropsychiatric diseases. An advisory committee composed of highly regarded principal investigators in glial cell research, gut-brain axis and the role of the gut microbiome in immune mediated diseases will provide additional guidance. Dr. Tankou’s career development plan is comprehensive, including frequent meetings, specific relevant coursework, and departmental support centered on mentoring early career investigators. She has and will continue to attend seminars as well as national and international conferences where she will present her research, establish collaborations, and learn of recent advances in the field. Dr. Tankou’s research utilizes cutting-edge approaches to advance understanding of the role of the gut microbiota on astrocyte barrier function. She proposes to identify communities of gut microbes and their metabolites that regulate astrocyte barrier function and their impact on central nervous system (CNS) inflammation. Dr. Tankou preliminary data have demonstrated that butyrate- producing bacteria as well as butyrate modulate astrocyte barrier function via induction of astrocytic claudin-4. In the first specific aim, experiments will be conducted to identify human gut derived bacteria and gut microbiota derived metabolites that modulate astrocytic CLDN4 expression. The second aim will examine the effect of butyrate on (1) astrocytic CLDN4 expression, (2) immune cell trafficking across the glia limitans and (3) CNS inflammation in EAE mice. The Icahn School of Medicine has demonstrated commitment to Dr. Tankou’s career with a 75% protected faculty position to conduct research. She hopes to develop innovative microbiome-based approaches to target neuroinflammation and neurodegeneration in MS.

NIH Research Projects · FY 2025 · 2023-08

PROJECT SUMMARY Mitral valve prolapse (MVP), identified in 1-3% of the general population, is the most common cardiac valvular abnormality, with complications that include heart failure, ventricular arrhythmias and sudden cardiac death (SCD). It has been estimated that the incidence of MVP-related SCD is 0.14% to 1.5% per year, depending on the clinical characteristics of the population studied. While there have been multiple features identified as markers of increased risk, left ventricular replacement fibrosis appears to be a consistent finding in Arrhythmic MVP. Late gadolinium enhancement (LGE) by cardiac magnetic resonance imaging (MRI) is considered the most sensitive and specific modality for assessing the presence and distribution of replacement fibrosis and it has been strongly associated with increased incidence of arrhythmic events in patients with MVP. Preliminary investigations from our group suggest that these fibrotic changes may be preceded by a chronic inflammatory phase and that inflammation and scarring may be part of a continuum of ventricular transformation and directly associated with arrhythmia development and complexity. We now propose an in-depth characterization of the relationship between intensity and pattern of 18F-fluorodeoxyglucose (FDG) uptake on hybrid Positron Emission Tomography (PET)/MRI, arrhythmia burden, severity of MVP and mitral regurgitation (MR). Detailed data including patients’ baseline characteristics, echocardiographic features, histological and biomarker data, arrhythmic burden and characterization will be obtained in patients with MVP, mild, moderate and severe MR, in order to establish the correlation between the disease process in its various stages and the PET/MRI phenotype. Specifically, in Aim 1 we will establish the inflammatory origin of the 18F-FDG signature in a cohort of patients with MVP, severe MR and class I/II indications for mitral valve surgery. Histology and serum for biomarker analysis will be collected at the time of surgery. Patients will additionally undergo a second imaging session with a novel PET tracer, 68Ga-DOTATATE, more specific for inflammation. In Aim 2, patients with MVP, mild or moderate MR, and a history of ventricular ectopy, who do not have an indication for surgery, will be enrolled into a longitudinal observational clinical study. We will perform 18F-FDG PET/MRI imaging, echocardiography, 7-day event monitoring (PVC burden and complexity) as well as collect circulating biomarkers at baseline and at follow- up after 24 months. Lastly, in Aim 3, we will assess the impact of MV surgery on myocardial inflammation and function, by repeating the same assessment as in Aim 2 but 12 months post-surgery to explore associations between MV surgery and changes in myocardial inflammation. With this comprehensive approach, our ultimate goal is the creation of a novel platform for the assessment of MVP, particularly as it relates to risk stratification of ventricular arrhythmias and SCD. We posit that the results of our studies may lead to more accurate imaging- guided patient management and have the potential to significantly influence current guideline recommendations for risk stratification assessment, medical therapy, and timing for surgical intervention.

NIH Research Projects · FY 2025 · 2023-08

The SARS-CoV-2 pandemic represents an exceptional public health crisis highlighting the need for better understanding of the mechanisms controlling broadly protective immune responses and generating vaccine candidates able to elicit such responses. The program project entitled “Programming Long-lasting Immunity to Coronaviruses (PLUTO)” proposes a comprehensive research plan towards designing pan- sarbecovirus and pan-betacoronavirus vaccines with broad protection by applying in-depth B cell characterization in the context of coronavirus immune histories imprinted by successive vaccinations and/or infections. Two complementary research projects will establish correlates of robust, durable and protective coronavirus humoral immunity (Project 1) as well as design and test efficacy of viral variant-proof pan-sarbecovirus and pan-betacoronavirus vaccines (Project 2). The Cores will synergize with the two research projects to support the successful completion of the research aims. The Administrative Core will manage the consortium, coordinate cross-project activities, and create the structure and environment needed to accomplish PLUTO's goals. The Antibody Core will develop large panels of recombinant monoclonal antibodies (mAbs) against coronavirus spike proteins to define specificity and breath of immune responses elicited by coronavirus infections and/or vaccinations in humans and animal models. The Animal Model Core will provide a central resource with approvals, facilities, and expertise to assess efficacy of broadly cross-reactive coronavirus antibodies and vaccines in robust pre-clinical models against a spectrum of coronaviruses, including Select Agents. A multidisciplinary team of scientists from five institutions who have an outstanding track record of working collaboratively will conduct the proposed studies. The Research Projects will collaborate with each other and with the Antibody and Animal Model Cores, coordinated by the Administrative Core. The integrated and synergistic activities across Projects and Cores will drive the successful completion of the program project's ambitious research agenda, enabling achievement of the long-term PLUTO goal of developing variant-proof pan- sarbecovirus and pan-betacoronavirus vaccines. These findings will contribute to curbing the current SARS- CoV-2 pandemic and mitigate the risk of future pandemics with coronaviruses.

NIH Research Projects · FY 2025 · 2023-08

PROJECT SUMMARY All vector-borne flavivirus NS5 proteins suppress host type I interferon (IFN) signaling, which is critical to successfully infecting humans and causing disease. Inhibitors of this function of NS5 or viruses engineered to lack this activity may be effective antiviral therapies and attenuated vaccines, respectively. However, a deeper understanding of how the flavivirus NS5 protein acts to suppress IFN is needed. Despite the importance of inhibiting IFN signaling, and the high degree of sequence conservation between NS5 proteins within this genus, flaviviruses have evolved numerous distinct ways to antagonize this innate immune response. Many flavivirus NS5 proteins, including those of dengue (DENV), Zika (ZIKV), and yellow fever (YFV) viruses, inhibit the Signal Transducer And Activator Of Transcription 2 (STAT2) protein, which is a transcription factor that mediates IFN signaling. In this application, we propose to fill critical gaps in our understanding of the ZIKV NS5-STAT2 interface by defining the essential viral and host genetic determinants for this interaction at the highest possible, single amino acid, resolution through deep mutational scanning (DMS). In Aim 1, we will screen libraries of all possible single amino acid ZIKV NS5 variants for the ability to suppress IFN signaling. We will examine these determinants in a range of flaviviruses to understand functional conservation and mechanisms. In Aim 2, we will identify how STAT2 genetics impact the ability of ZIKV NS5 to suppress IFN signaling and mediate infection. Finally, in Aim 3 we will define how ZIKV NS5 induces the degradation of human STAT2 by identifying the STAT2 sites where NS5 induces ubiquitination and the host factors ZIKV NS5 recruits to mediate this modification. The results of this project will provide in-depth insights into flavivirus host cell interactions and replication mechanisms that may aid in the development of therapies for ZIKV, and could perhaps be further applied in combating other future virus outbreaks.

NIH Research Projects · FY 2025 · 2023-08

Sickle cell disease (SCD) is an inherited disorder of human adult hemoglobin, which primarily afflicts Americans of African descent. The mutant hemoglobin, Hb S, polymerizes upon deoxygenation, leading to impaired red blood cell rheology, microvascular occlusion, chronic inflammatory state, and chronic hemolytic anemia, culminating in chronic organ damage and a shortened life expectancy. SCD is an orphan disease, with an estimated ~110,000 patients in the U.S. who suffer from disparities and discrimination and increased health care utilization. Until recently, the management of the disease has been largely confined to symptom control, with pain management and transfusions. In 1998, the U.S. FDA approved hydroxyurea (HU) as the first disease modifying therapy for SCD. Subsequent studies in children and adults with SCD has confirmed the beneficial effects of HU, with prevention of organ damage and decrease in mortality. In the past five years, three additional disease modifying drugs (L-glutamine, voxelotor, and crizanlizumab) targeting different mechanisms in disease pathophysiology have been approved by the FDA, broadening the available therapeutic armamentarium for SCD. Although this is a welcomed development, knowledge gaps exist on the choice of the most effective disease modifying therapy or combinations, based on a spectrum of sub- phenotypes of the disease. This gap is unlikely to be filled by knowledge gained from randomized clinical trials involving the use of FDA approved therapies. This application seeks to meet this unmet need by taking advantage of the infrastructure (prospective Registry of 2400 SCD patients) provided by the NHLBI funded Sickle Cell Disease Implementation Consortium (2016-2022) consisting of eight Centers throughout U.S. We propose to approach this problem by enrolling 1200 patients (150 patients from each Center) by applying the following specific aims: 1) Compare the effect of novel disease modifying therapies (L-glutamine, voxelotor, and crizanlizumab) on clinical outcomes in individuals with SCD. We will follow these individuals prospectively for 5 years, emulating data collection protocols and eligibility from key, interventional phase III SCD trials, and monitor organ injury NT-proBNP for heart and lung injury, urine albumin/creatinine ratio for kidney function, hemolysis score for blood, as well as symptom burden (ASCQ-Me) 2) Identify genetic and genomic predictors of response to disease modifying therapies, by a) whole exome sequencing and b) RNA seq (mononuclear cells, retics, platelets); and 3) integrate study data into the CureSCi metadata catalog to enhance future cross study analyses.

NIH Research Projects · FY 2024 · 2023-08

ABSTRACT Persons with serious illness suffer from poor symptom control, decreased quality of life (QoL) and poor communication with their healthcare providers, especially in terms of goals of care discussions (GOCD). Palliative care, when offered alongside disease management, offers improved symptom control, QoL, communication, caregiver satisfaction and reduced caregiver anxiety. Due to a limited specialty-trained palliative care workforce, however, patients and their caregivers often cannot access these benefits, especially in the community. These needs are particularly acute in advanced cancer and HF, the two leading causes of death in the US which also model the most common illness trajectories. The dynamic nature of these illnesses presents distinct symptom patterns and changing functional status that require an adaptive, dynamic model of palliative care delivery. Yet, workforce shortages prevent scaling of existing community-based specialty palliative care models. To meet patient/caregiver dyads' needs with a limited workforce, new models that deploy palliative care clinicians based on patient's illness trajectory and changing needs are required. The innovative TIER-PALLIATIVE CARE (TIER-PC) model provides the right level of care to the right patients at the right time. TIER-PC increases the number and intensity of specialty trained palliative care disciplines added to the dyad's care team as their symptoms worsen and function declines. In Tier 1, patients who can care for themselves and have easily managed symptoms, receive support from a community health worker (CHW) trained to elicit illness understanding in a culturally competent way. In Tier 2, for patients with poorer function and mild symptoms, a social worker (SW), trained in serious illness communication, joins the CHW to further elicit patients' illness understanding and goals, and provide caregiver support. In Tier 3, as function decreases and symptoms increase, an advance practice nurse (APN) joins the CHW+SW to manage complex symptoms. In Tier 4, for those patients with the poorest function and worst symptoms, an MD joins to address the most complex needs (e.g., end-of-life treatment preferences and multifaceted symptom control). The CHW follows dyads longitudinally across all tiers and re-allocates them to the appropriate tier based on their evolving needs. We will evaluate TIER-PC's efficacy in a multi-site, single blinded, two arm, randomized controlled trial. Patients with advanced cancer or HF will receive regular assessments by the TIER-PC team to: address symptom and psychosocial needs; improve illness/prognostic understanding; prescribe medications; and address goals of care. We will enroll and randomize 400 patients with HF or cancer and their family caregivers to receive TIER- PC or an augmented control. We will follow dyads for 12 months to determine if TIER-PC: improves patients' symptom control and QoL (primary outcomes), patient-reported GOCDs and caregiver satisfaction; reduces caregiver anxiety and post-traumatic stress; and decreases patients' healthcare utilization and cost. By matching demand to the scarce workforce, our scalable model can improve care for patients with cancer or HF.

NIH Research Projects · FY 2024 · 2023-08

SUMMARY Membranous nephropathy (MN) is a glomerular disease due to the deposition of anti-podocyte antibodies in the subepithelial space of the glomerular basement membrane. This leadis to complement-mediated podocyte injury and, in ~30% of patients, to the development of end stage kidney disease within 10 years from diagnosis. Most of the research in MN has focused on the autoantibody specificities and has led to the identification of phospholipase 2A receptor (PLA2R) as the main target antigen in 70%-80% of the patients. Conversely, little is known on autoreactive T cells, despite the evidence from other antibody-mediated autoimmune diseases clearly showing a critical pathogenic role of autoreactive T cells, efficacy of T cell targeting treatments, and our preliminary data documenting that autoreactive T cells are present in the circulation of MN patients. Aim 1 of the present project will develop a new strategy to capture the T cell receptor (TCR) repertoire of PLA2R-reactive T cells in MN patients. We will apply high-throughput paired T cell receptor alpha and beta chain DNA sequence capture for renewable TCR gene library generation and functional screening from patient T cells. We will physically link TCR gene sequences for cloning into cellular display libraries, enabling repeated in vitro functional analyses of TCRs in ways that are impossible with alternative available techniques. Aim 2 will apply these technologies for the study of the single-cell transcriptional profile of CD4+ T cells. These data will reveal the characteristics of autoreactive TCRs in a previously collected samples from MN patients with remission versus active disease, setting the stage for expanded clinical studies. Overall, this project will collect and analyze immune response data from MN patients with unprecedented molecular scope and scale. Our approach is innovative because it couples carefully designed clinical sample sets with new high-throughput approaches in TCR analysis to comprehensively interrogate the molecular mechanisms of T cell responses in MN patients. The proposed research is significant because it will provide important tools for mechanistic studies aimed at identifying new biomarkers and therapeutic targets for MN patients.

NIH Research Projects · FY 2025 · 2023-08

Project Summary Alzheimer’s disease and Alzheimer’s disease-related dementias (AD/ADRD) are one of the most common disorders in adults aged 65 or above. Older Chinese Americans have a high risk of inaccurate diagnosis or delayed diagnosis of AD/ADRD due to the absence of culturally and linguistically appropriate assessment batteries and normative data. The National Alzheimer’s Coordinating Center (NACC) developed a Mandarin version of the Uniform Data Set (UDS) test battery for evaluation of older Chinese Americans in AD/ADRD research. However, several important limitations have been observed for this specific battery. For example, the translations did not include Cantonese, which together with Mandarin, is the most commonly spoken language in the US after English and Spanish. It is important to note that Cantonese and Mandarin are significantly different from one another in both spoken and written forms. Secondly, the test items and instructions that comprise the overall battery were developed through verbatim translations, which are not always culturally and linguistically relevant to the diverse older Chinese American population. Furthermore, a lack of normative data creates barriers to accurate interpretation, diagnosis, and prognostication of AD/ADRD. The proposed study aims to develop minimally biased Mandarin and Cantonese versions of the NACC UDS test battery, guided by the pilot data collected for the Mandarin version of the current UDS battery (Aim 1). The team will also generate sociodemographic-adjusted normative data using 400 older Chinese Americans with normal cognition (Aim 2) at the Alzheimer’s Disease Research Centers (ADRCs) at Icahn School of Medicine at Mount Sinai (ISMMS; n=200) and the University of California, San Francisco (UCSF; n=200). Lastly, the team will examine if cognitive performance correlates with corresponding neuroanatomical regions identified via brain magnetic resonance imaging (MRI) (Aim 3). 300 participants will be required for the MRI sub-study; 100 participants will come from the 400 cognitively normal participants already enrolled in Aim 2 (from each site: n=50), while an additional 100 MCI and 100 AD/ADRD (from each site: n=50 MCI and n=50 AD/ADRD) will need to be recruited. Participants must be primarily Mandarin/Cantonese speaking and aged 65 or above. All enrollees will undergo a dementia evaluation at the ADRCs using the newly developed Chinese versions of the NACC UDS battery. The study PIs (Li & Tee) have been successful in recruiting and evaluating Chinese speaking older adults at their respective ADRCs, generating a combined sample of >600 participants. This cohort will provide a recruitment pipeline for the proposed study. The PIs also have established relationship with stakeholders in the older Chinese communities to assist with recruitment should it become a challenge. This novel project will provide linguistically and culturally appropriate assessment tools for future cross-geographic studies that include older Chinese Americans and add value to the NACC research database. The study results will also provide normative data for the detection and diagnosis of cognitive deficits in this underserved population, which is currently nonexistent.

NIH Research Projects · FY 2024 · 2023-08

PROJECT SUMMARY/ABSTRACT More than a quarter of all adults older than 75 years have symptomatic stable ischemic heart disease. Stress nuclear imaging is the one of the most common tests performed for diagnosis and management of coronary artery disease in these older adults. Older adults are more likely to have co-existing impairments in function, cognition and multimorbidity, which may limit their benefit from imaging tests and post-test treatment, alike. Although stress testing is often used to evaluate symptoms, clinicians are less likely to refer older adults for revascularization or to optimize their medical therapy, even if stress test results are severely abnormal. In turn, this can result in overuse of testing, increased complications and cost of care without improving patient outcomes. To help older patients presenting with suspected ischemic symptoms make a well-informed decision, clinicians should contextualize the benefits of imaging and treatment strategies post imaging in context of elicited goals of care, clinical impairments. It is critical to understand presentation, cardiac risk factors and potential age-related how to improve shared decision making among older adults and identify areas of imaging test overuse or underuse among older adults with symptomatic stable ischemic heart disease. In this project, I use a multi-stakeholder approach to understand post-stress test decision making from patient, caregiver and physician perspectives and study its association with outcomes among symptomatic older adults with suspected or known CAD. My research aims are to (a) understand older patient and caregiver attitudes about post-imaging treatment choice in context of their preferred outcomes and age-related impairments through focus group interviews and (b1) examine the association between cardiovascular and geriatric risk factors on post-imaging treatment choice (i.e., invasive referral vs. medical optimization); and (b2) compare the association of treatment received post-imaging and patients' symptoms, function and quality of life among symptomatic older adults  75 years undergoing clinically indicated stress nuclear imaging within our health system. This study will help inform my future work aimed at developing and testing personalized decision aids to guide choice of testing and treatment for symptomatic older adults with CAD. This GEMSSTAR award will also provide me with the support, mentorship and training required to become a leader in field of cardiovascular imaging and shared decision-making for older adults with stable ischemic heart disease.

NIH Research Projects · FY 2025 · 2023-08

PROJECT SUMMARY Hypertension is a leading cause of death and disability in the United States. Longstanding healthcare disparities in hypertension prevalence and outcomes persist, in part because interventions shown to be effective in clinical trials have not been translated into clinical practice. The Doctor of Nursing Practice (DNP) degree prepares experienced nurses to expertly manage chronic conditions and improve healthcare delivery through continuous translation of emerging evidence into clinical practice. The number of DNP graduates is growing, but structured translational research training opportunities with expert mentors in clinical settings are lacking, and DNP graduates report the need for additional didactic and hands-on skill building. The overarching goal of the Translational Research and Implementation Science for Nurses (TRAIN) Program is to prepare DNP students for leadership in translational research to improve hypertension outcomes and reduce healthcare disparities therein. TRAIN is a novel 12-week summer program that will offer 8 DNP students an enhanced curriculum incorporating translational research methods with a special focus on implementation science related to hypertension prevention and management across communities. The objectives of TRAIN are to: (1) pair motivated DNP students with mentors to gain direct experience on a National Heart, Lung, and Blood Institute mission-relevant clinical or health services research project; (2) provide participants with a didactic curriculum that enhances training in the principles and methods of translational research; (3) enhance participants’ research-related technical, communication, and career-building skills and confidence to facilitate successful participation and leadership in translational research; and (4) encourage sustained mentorship and professional network building by establishing forums for ongoing contact and collaboration between program faculty, alumni, and current participants. The specific aims of TRAIN are to: (1) Develop, implement, iteratively refine, and sustain the 12-week summer program delivered via hands-on mentored research experience and classroom instruction; (2) Recruit and retain cohorts of DNP students via existing partnerships with schools of nursing; (3) Establish a network of TRAIN alumni and disseminate program resources to support translational research training for DNP students in other healthcare settings nationally; and (4) Evaluate the impact of TRAIN on student competencies, self-efficacy, and career trajectory using pre- and post- self-assessments, faculty assessments, and career goal assessments. The TRAIN Program will leverage the extensive research education resources of the Center for Nursing Research and Innovation at the Icahn School of Medicine at Mount Sinai.

NIH Research Projects · FY 2025 · 2023-08

PROJECT SUMMARY Alzheimer’s disease (AD) is a grave neurodegenerative disorder characterized by unrelenting memory loss and deficits in executive function with no effective treatment. Accumulating evidence from genome wide association studies (GWAS) posit that the brain’s innate immune system plays a central role in AD etiology. As the central nervous system’s resident immune cells, microglia have thus emerged as attractive cells to target therapeutically. Such drug targets may lie within the MS4A locus, a region associated with protection from AD, later age-at- onset, and increased levels of sTREM2, a biomarker of microglial activity. This region contains multiple genes within the membrane-spanning 4-domain subfamily A (MS4A) gene cluster, which together encode structurally related transmembrane proteins largely expressed by immune cells whose exact functions are not yet understood. Our work nominated a candidate causal variant within this locus, rs636317, which disrupts an anchor binding site for the chromatin remodeling protein CTCF and is associated with increased expression of MS4A4A and MS4A6A in myeloid cells. This proposal aims to directly test the hypothesis that by modulating MS4A4A and MS4A6A expression via differential CTCF binding, variant rs636317 alters microglial cell function in the context of disease. In AIM 1, I will determine the functional impact of MS4A genes in vitro using CRISPR-edited human induced pluripotent stem cell (iPSC)-derived microglia (iMGL). Given known interactions between MS4A proteins and other immune receptors such as TREM2 and CLEC7A, I will perform targeted functional assays related to immune signaling in iMGLs from two iPSC models: MS4A4A/MS4A6A knockout lines and isogenic lines homozygous for the protective or risk alleles of the candidate causal variant. In AIM 2, I will employ a novel xenotransplantation model involving direct injection of human microglia precursor cells into the mouse brain to evaluate the effect of these genes on cell function in vivo and in the context of disease using 5xFAD chimeric mice. I hypothesize that knocking out MS4A4A and MS4A6A in human microglia promotes protective microglial responses, ameliorating plaque containment and subsequent cognitive decline. Elucidating the function of this gene family and the specific role it plays in AD progression has the potential to greatly impact public health. The proposed research and rigorous training plan outlined here will equip me with the skills needed for a successful future career in neurodegeneration leading an independent research team.

NIH Research Projects · FY 2024 · 2023-08

Bats are perhaps the most fascinating but least understood mammalian order. It is clear that, although bats are a critically needed new model organism, limited access to animal and cell models has hindered their study. We recently generated the first induced pluripotent stem cells (iPSCs) from a bat (R. ferrumequinum) and discovered that bat iPSCs had a unique transcriptomic profile enriched in metabolomic and immune pathways ketogenic metabolism and a unique inflammasome response. We plan to generate additional to test if our novel protocol can be used for any bat species and that essential metabolic genes uniquely expressed only in bat cells, including HMGC2, can be knocked out using CRISPR/Cas9. We will also evaluate if the inflammatory response is altered in myeloid cells derived from bat iPSCs. Bat stem cell lines and differentiated progeny will help address bat physiology’s most tantalizing questions, including immunity.