Upstate Medical University

NIH Research Projects · FY 2026 · 2024-05

Frontotemporal dementia (FTD) encompasses a spectrum of neurodegenerative diseases caused by focal and progressive atrophy of frontal and/or temporal lobes and is the leading cause of dementia before the age of 60 and the second most common form of dementia after Alzheimer’s disease (AD). There is no cure. Among several variants within the FTD spectrum, the behavioral variant (bvFTD) is the most prevalent, accounting for nearly 50% of all FTD cases. bvFTD is characterized by marked changes in personality, impaired judgement and social conduct, and blunted emotion and affect, including a loss of empathy, which represents arguably the most distressing and defining feature of bvFTD. The underlying neural mechanisms are unknown. About 40-50% of FTD cases are familial and associated with mutations of over a dozen genes with diverse molecular and cellular functions, among which GGGGCC (G4C2) hexanucleotide repeat expansions (HREs) in the chromosome 9 open reading frame 72 (C9orf72, or C9) gene is the most common genetic cause of FTD. We established an bvFTD mouse model of empathy loss and observed that aged somatic transgenic mice expressing G4C2 HREs in C9orf72 exhibited blunted affect-sharing and failed to comfort distressed conspecifics by affiliative touch. Our preliminary studies found that a marked reduction of pyramidal neuron excitability in the dorsomedial prefrontal cortex (dmPFC) in aged mutant mice underlies their lost empathy. Remarkably, restoring dmPFC neuronal excitability rescued the empathy deficits in mutant mice, even at advanced ages when substantial cortical atrophy had occurred. These results establish dmPFC hypoexcitability as a potential pathophysiological basis of empathy loss in bvFTD. The goals of this R01 application are to define the prefrontal circuits mediating empathy-driven consolation behavior (Aim 1), delineate the intrinsic, synaptic, and circuit mechanisms of lost empathy in C9-bvFTD mouse models (Aim 2), and explore therapeutic strategies that can rescue, reverse, and prevent empathy loss in mutant mice (Aim 3). The proposed studies are fundamentally important and highly significant because they have the immediate potential to uncover novel pathogenic mechanisms and treatment strategies for FTD and related dementia.

NIH Research Projects · FY 2026 · 2024-02

Project Summary/Abstract: In this proposal we will address one of the major unanswered questions in vision: the mechanism of rhodopsin delivery and loading into new photoreceptor discs. This perpetual process is particularly robust in rods where, for mammals, the daily delivery of 30 million rhodopsins supports the formation of 80 new discs in each rod. While rhodopsin synthesis and delivery to the rod apical region has been intensively studied, almost nothing is known about what happens afterward, thus representing a critical knowledge gap. Roadblocks to under-standing this process include the complexity of the inner segment-outer segment interface that is below the resolution limit of fluorescence microscopy and the limitations of prior approaches that relied almost exclusively on static analyses in fixed tissues. To overcome these roadblocks, we have implemented live-cell 3D super resolution single particle tracking microscopy (3D-sptPALM) to directly examine the dynamics of individual rhodopsins within discrete photoreceptor compartments in real time. We will exploit a key mouse model, the retinal degeneration slow (rds) mouse, which allows us to intentionally vary the level of outer segment membrane complexity while retaining the photoreceptor cilium. Our preliminary results show the entry of individual rhodopsins into photoreceptor cilia, their transport along the cilium and, remarkably, their exit back into the inner segment, for the very first time. We will address the following fundamental questions: Aim 1: How does rhodopsin enter (and exit) the photoreceptor cilium? Aim 2: How is rhodopsin transported within photoreceptor cilia? Aim 3: How are rhodopsins loaded into new discs?

NIH Research Projects · FY 2025 · 2024-02

Summary Mutations in USH2A (usherin) are common causes of autosomal recessive blinding diseases in non-syndromic retinitis pigmentosa as well as syndromic Usher syndrome type II that manifests congenital hearing loss as well. There is no effective therapy for these diseases. How usherin contributes to photoreceptor health is poorly understood. An usherin-deficient animal model that exhibits severe retinal degeneration as in human patients is essential for understanding the pathological mechanisms and for development of effective therapies to preserve or restore vision. This project is aimed at generating an usherin-deficient model that recapitulates the phenotypes found in human patients.

NIH Research Projects · FY 2026 · 2024-01

PROJECT SUMMARY I am an academic clinician scientist with a focus on the genetics of respiratory diseases. My overarching career goal is to make an important contribution to the public health burden of chronic respiratory diseases. I aim to become an independent investigator with the skill set to utilize integrative ‘omic techniques for the improved biological understanding and clinical management of chronic obstructive pulmonary disease (COPD). The proposed research combines my prior experience in genetics and transcriptomics with training in genetic association, transcriptomic analyses, and machine learning, in order to better understand the variability in COPD genetic risk. The hypothesis of this proposal is that there are genetic variants and transcriptomic factors that are associated with resilience to COPD. This will be tested by leveraging existing data from multiple well-phenotyped studies from the NHLBI TransOmics for Precision Medicine (TOPMed) program. Specific Aims: (1) Identify genetic variation associated with resilience to COPD against a background of elevated genetic risk; (2) Define clinical, imaging, and blood gene-expression features of COPD resilience; and (3) Predict lung-tissue gene-expression profiles of COPD risk and resilience from blood gene-expression data. The cutting-edge research plan utilizes innovative methodologies to characterize genetic and transcriptomic resilience to COPD. It is accompanied by a training plan that will provide me with the skills to complete the research aims and the experience to transition to an independent research career. I plan to submit an R01 expanding upon the characterization of genetic and transcriptomic resilience in COPD by combining multi-omic risk- and resilience-scoring and lung-tissue gene-expression imputation to improve understanding of the biological mechanisms that contribute to observed clinical heterogeneity in COPD. In particular, I have four training goals that build upon my existing background in respiratory genetics. (1) Strengthen my knowledge of biostatistics, statistical genomics, and bioinformatic methods; (2) Expand my skills in transcriptomic methodologies; (3) Gain experience and expertise in the development and implementation of machine-learning algorithms; and (4) Further develop my mentoring skills and understanding of study design. I am supported by a mentoring team with complementary skillsets and successful mentoring careers, which, together with my experience, training, and substantial preliminary data, will guarantee the success of this proposal. The findings may pave the way for the development of precision risk-prediction approaches, while implementing a novel methodology to address one of the most important challenges in the field today: identification of genetic and transcriptomic resilience to COPD.

NIH Research Projects · FY 2025 · 2023-09

Project Summary/Abstract Vision, in general, and stereopsis, in particular, depends on the selective decussation of retinal ganglion cell axons and their termination in an orderly topographic manner. Axonal decussation is directed by the radial glia and midline line neurons at the optic chiasm. The radial glia and midline neurons attach to the pial basement membrane (PBM), a cell adherent, highly organized extracellular matrix sheet that forms the basal surface of the brain including the chiasm. A key component of the PBM are laminins. In other brain regions laminins containing the 2 subunit (2 laminins) provide environmental cues that control tissue and cellular organization including polarity, proliferation, and differentiation. We hypothesize that 2 laminins in the PBM of the chiasm function to polarize the radial glia and midline neurons. This polarization, in turn, regulates the spatial organization of guidance cues thereby regulating axon decussation. Consistent with this hypothesis, we found that loss of 2 laminins from the PBM decreased axonal decussation resulting in an increased ipsilateral projection. We will critically test this hypothesis in three aims. In Aim 1 we will determine the role of 2 laminins in the control of axonal guidance cue expression during the early, peak, and late phases of axon growth. In Aim 2, we will determine which laminin receptors are required for the polarity of radial glial cells and axon decussation using a combination of in vivo and in vitro approaches. Our in vivo experiments will employ cell specific deletion of laminin receptors, while our in vitro experiments will employ a technically innovative organotypic approach using function blocking techniques. In Aim 3, we will determine how 2 laminins control the radial glia and midline neuron cell polarity using sparse labeling of the cells and high-resolution microscopy. The experiments proposed here will define the role of the β2 laminins during optic chiasm and tract formation. The findings from this work will pave the way to exploit cell-matrix interactions for the development of rational strategies to promote the guided growth and decussation of regenerating retinal ganglion cell axons.

NIH Research Projects · FY 2025 · 2023-09

Muscle atrophy (or wasting) is defined by reduced myofiber size and number, which increases morbidity and mortality and decreases quality of life. One of the mechanisms of muscle atrophy is the loss of proteostatic balance. When protein degradation exceeds synthesis, protein content is decreased to reduce myofiber size and muscle mass. How the balance between protein synthesis and degradation is disturbed in diseased and aged skeletal muscle in unknown. Mitochondrial dysfunction plays an important role in skeletal muscle atrophy under many disease conditions and during normative aging, with the underlying mechanism remaining poorly understood. Perturbations in oxidative phosphorylation and the subsequent increase in reactive oxygen species production, collectively termed “bioenergetic defects”, have been proposed to drive muscle loss. However, accumulating evidence suggests that substantial levels of bioenergetic deficiency and oxidative stress are insufficient to cause muscle wasting. Therefore, if mitochondrial dysfunction does indeed result in muscle loss, it may involve bioenergetically independent factors. The Chen lab recently found that various forms of mitochondrial damage can reduce mitochondrial protein import. This causes proteostatic stress in the cytosol, termed mitochondrial Precursor Overaccumulation Stress (mPOS), followed by global remodeling of proteostasis. We recently generated a transgenic mouse line that moderately overexpresses the mitochondrial inner membrane protein, Ant1. We found that Ant1-induced mitochondrial protein import stress causes progressive muscle atrophy, accompanied by reduction of mitochondrial respiration. However, whether muscle atrophy is caused by bioenergetic deficiency or bioenergetic-independent stressors remains unknown. Interestingly, RNA-seq analysis revealed a robust activation of the integrated stress response (ISR), which in turn represses global protein synthesis and activates autophagy. ISR activation is commonly found in tissues derived from patients with mitochondrial disease. Using this unique mouse model, we propose to determine the molecular mechanisms of mitochondria-induced muscle atrophy and ISR activation. In Aim 1, we will determine the mechanism by which mitochondrial protein import stress induces muscle wasting. In Aim 2, we will determine whether ISR activation protects skeletal muscle from myofiber death and myopathy in the setting of mPOS. The long-term goal of this project is to understand how bioenergetics-independent mitochondrial stress signaling promotes chronic muscle wasting in normative and non-normative aging. The results of this application may help establish a bioenergetics-independent pathway for treating mitochondria-induced muscle disease and possibly sarcopenia.

NIH Research Projects · FY 2026 · 2023-09

Sudden Unexpected Death in Epilepsy (SUDEP) is the leading cause of death in epilepsy. Many SUDEP cases had genetic variants linked to cardiac arrhythmias, particularly Long QT Syndrome (LQTS). Our lab and others showed that LQT2 patients are at a >2-fold higher risk of epilepsy, compared to genotype negative family members. LQT2 is caused by KCNH2 variants that encode a K+ channel protein (Kv11.1), which produces K+ current (IKr). It is critical for cardiac repolarization, stabilizes the neuronal resting membrane potential, and suppresses repetitive firing. People with KCNH2-mediated epilepsy and LQT2 need safe and effective anti- seizure medications (ASMs). A critical barrier is the lack of a clinically relevant animal model of LQT2 with epilepsy. We will develop the first translational model of Kcnh2-mediated epilepsy, SUDEP, and LQT2. As LQT2 patients with KCNH2 pore-domain variants are at the highest risk of seizures, we used CRISPR-Cas9 to generate rabbits with a heterozygous frameshift mutation in the Kcnh2 pore-domain (Kcnh2(+/mut)). This model has superior construct validity. Due to rodent vs. human differences in cardiac electrical function, and unphysiological Kcnh2 expression patterns, present models are not appropriate for translational studies of Kcnh2-mediated neuro- cardiac pathologies. Many rodent models fail to reproduce the natural progression of clinical epilepsy, include non-seizure related neuronal damage, require triggers that are not physiologically relevant, and have low predictive validity for ASM screening. Rabbits are established models for drug testing, and studying seizures, arrhythmias, and sudden death. In contrast to rodents, neuronal cell-types are similar in humans and rabbits. R61: External Face Validation: Using quantifiable and clinically relevant endpoints, we will test if Kcnh2(+/mut) rabbits reproduce the neuro-cardiac pathologies seen in LQT2 patients with epilepsy. Preliminary data indicates that we generated a clinically-relevant rabbit model of Kcnh2-mediated epilepsy, SUDEP, and LQT2. There is reduced Kv11.1 expression in the brain and heart, QTc prolongation, spontaneous noncardiogenic epileptic seizures, and spontaneous seizure-mediated sudden death. R33: Despite LQT2 patients being at a high risk of epilepsy and SUDEP, there are no established ASMs for LQT2 patients with epilepsy. We demonstrated that LQT2 patients are at an increased risk of arrhythmias when on vs. off ASMs, particularly Na+ channel blocking ASMs (e.g., phenytoin). External Face Validation: (1) We will demonstrate that myocytes and cortical neurons from Kcnh2(+/mut) rabbits have reduced IKr and are hyperexcitable. (2) Similar to LQT2 patients, cellular and in vivo assays will test if phenytoin has adverse cardiac effects in Kcnh2(+/mut) rabbits. Preliminary data indicates phenytoin blocks IKr and causes a larger increase in QTc in Kcnh2(+/mut) vs. WT rabbits, which suggests predictive validity of our model. Impact: We will develop a model of Kcnh2-mediated epilepsy, SUDEP, and LQT2 that reproduces human LQT2 neuro-cardiac pathologies. It will provide a platform for identifying effective and safe ASMs to reduce seizures and SUDEP in LQT2, and complements our research using the LQTS patient registry.

NIH Research Projects · FY 2024 · 2023-09

Sudden Unexpected Death in Epilepsy (SUDEP) is the leading cause of death in epilepsy. Many SUDEP cases had genetic variants linked to cardiac arrhythmias, particularly Long QT Syndrome (LQTS). Our lab and others showed that LQT2 patients are at a >2-fold higher risk of epilepsy, compared to genotype negative family members. LQT2 is caused by KCNH2 variants that encode a K+ channel protein (Kv11.1), which produces K+ current (IKr). It is critical for cardiac repolarization, stabilizes the neuronal resting membrane potential, and suppresses repetitive firing. People with KCNH2-mediated epilepsy and LQT2 need safe and effective anti- seizure medications (ASMs). A critical barrier is the lack of a clinically relevant animal model of LQT2 with epilepsy. We will develop the first translational model of Kcnh2-mediated epilepsy, SUDEP, and LQT2. As LQT2 patients with KCNH2 pore-domain variants are at the highest risk of seizures, we used CRISPR-Cas9 to generate rabbits with a heterozygous frameshift mutation in the Kcnh2 pore-domain (Kcnh2(+/mut)). This model has superior construct validity. Due to rodent vs. human differences in cardiac electrical function, and unphysiological Kcnh2 expression patterns, present models are not appropriate for translational studies of Kcnh2-mediated neuro- cardiac pathologies. Many rodent models fail to reproduce the natural progression of clinical epilepsy, include non-seizure related neuronal damage, require triggers that are not physiologically relevant, and have low predictive validity for ASM screening. Rabbits are established models for drug testing, and studying seizures, arrhythmias, and sudden death. In contrast to rodents, neuronal cell-types are similar in humans and rabbits. R61: External Face Validation: Using quantifiable and clinically relevant endpoints, we will test if Kcnh2(+/mut) rabbits reproduce the neuro-cardiac pathologies seen in LQT2 patients with epilepsy. Preliminary data indicates that we generated a clinically-relevant rabbit model of Kcnh2-mediated epilepsy, SUDEP, and LQT2. There is reduced Kv11.1 expression in the brain and heart, QTc prolongation, spontaneous noncardiogenic epileptic seizures, and spontaneous seizure-mediated sudden death. R33: Despite LQT2 patients being at a high risk of epilepsy and SUDEP, there are no established ASMs for LQT2 patients with epilepsy. We demonstrated that LQT2 patients are at an increased risk of arrhythmias when on vs. off ASMs, particularly Na+ channel blocking ASMs (e.g., phenytoin). External Face Validation: (1) We will demonstrate that myocytes and cortical neurons from Kcnh2(+/mut) rabbits have reduced IKr and are hyperexcitable. (2) Similar to LQT2 patients, cellular and in vivo assays will test if phenytoin has adverse cardiac effects in Kcnh2(+/mut) rabbits. Preliminary data indicates phenytoin blocks IKr and causes a larger increase in QTc in Kcnh2(+/mut) vs. WT rabbits, which suggests predictive validity of our model. Impact: We will develop a model of Kcnh2-mediated epilepsy, SUDEP, and LQT2 that reproduces human LQT2 neuro-cardiac pathologies. It will provide a platform for identifying effective and safe ASMs to reduce seizures and SUDEP in LQT2, and complements our research using the LQTS patient registry.

NIH Research Projects · FY 2024 · 2023-09

Targeting neutrophils to harness myeloid responses for wound healing Chronic wounds represent a significant health problem in the United States. Delayed or non-resolving inflammation is a hallmark of the chronic wound and is sustained by myeloid cell accumulation and upregulated myelopoiesis. Metabolic conditions such as obesity contribute to this growing problem and influence myeloid response to wounds. The central hypothesis of this proposal is that obesity and diabetes dysregulate myeloid responses and thereby impairs wound healing. Our preliminary study using mouse models suggests a mechanistic link of neutrophil clearance in the bone marrow with myelopoiesis. We propose a translational study involving both mouse models and human specimens with three Specific Aims: In Aim 1, we will determine the mechanism by which neutrophil clearance in the bone marrow regulates myelopoiesis, with the hypothesis that neutrophils release extracellular vesicles that regulate myelopoiesis during their clearance. In Aim 2, we will determine the mechanism of inhibited neutrophil clearance in the bone marrow in chronic wounds and obesity, with the hypothesis that chronic wounds and obesity increase glutamine utilization in neutrophils and inhibit their clearance in the bone marrow. In Aim 3, we will bioengineer a nano-drug that target neutrophils and modify myeloid response. To achieve this, we will utilize a well-defined versatile telodendrimer to selectively deliver glutaminase inhibitor to neutrophils and will test the nano-drug in the preclinical mouse model of impaired wound healing in obesity. The proposed experiments will improve knowledge of myeloid responses during wound healing. The impact of these studies lies in the potential for translation to therapies that stimulate healing responses in hard-to-heal wounds. Also, the studies could lead to the development of assays that involve monitoring blood neutrophil survival as cellular biomarkers to aid in the selection of treatment options for patients with chronic wounds and/or obesity.

NIH Research Projects · FY 2026 · 2023-08

This application synergizes expertise from two groups, with one specialized in mitochondrial biology and proteostatic signaling and the other in V-ATPase biochemistry and vacuolar/lysosomal biology. Mitochondria are multifunctional organelles. In addition to their major role in ATP production, mitochondria are also involved in other cellular processes including stress signaling and cell death. However, under many pathophysiological conditions and during aging, to what extent impairment to non-bioenergetic mitochondrial functions contributes to the decline of cell fitness is poorly understood. We found that various mitochondrial stressors can directly induce proteostatic stress in the cytosol independent of energy metabolism, by a mechanism named mitochondrial Precursor Overaccumulation Stress (mPOS). The mechanisms by which mPOS affects cellular function and viability remain unknown so far. The lysosome (or vacuole in yeast) also carries out many cellular functions in the cell, including pH control, ion and amino acid homeostasis, protein degradation, autophagy and vesicular trafficking. Interestingly, defects in mitochondrial and lysosomal functions can both contribute to cell aging and aging-associated degenerative disorders, including Parkinson’s disease and amyotrophic lateral sclerosis. This odd coincidence invites the question of whether damage to mitochondria and lysosomes can synergize, either sequentially or additively, to affect a common cellular process critical for the fitness and survival of aged cells. To address this question, it is important to comprehensively describe how mitochondria and lysosomes interact at the molecular level to affect cellular functions. In this application, we focus on a novel mitochondria-to-lysosome stress signaling pathway, in which mitochondrial defects cause proteostatic stress to the vacuole/lysosome thereby affecting cell survival. The scientific premise of this application is based on our strong preliminary data from studies in yeast, cultured human cells and transgenic mice. More specifically, the Aim 1 of the proposal will test the hypothesis that specific mitochondrial stress can cause severe proteostatic damage to the yeast vacuole. The genetic amenability of the yeast system will enable us to discover genes that suppress the mitochondria-to-vacuole stress signaling and possibly, extend cell’s lifespan. In Aim 2, we will validate this novel mitochondria-to-lysosome stress signaling pathway in cultured mammalian cells. In Aim 3, we will test the hypothesis that mitochondrial stress causes lysosomal damage and affects tissue homeostasis in vivo, using a unique mouse model that we recently developed. We will determine the mechanism of the mitochondria-induced lysosomal damage in post-mitotic tissues. Success of our experiments may unravel a novel mechanism of cell demise that involves mitochondria-to-lysosome stress signaling. The results may ultimately help the better understanding of many aging-associated diseases that are co-manifested by mitochondrial and lysosomal defects.

NIH Research Projects · FY 2025 · 2023-08

Project summary There are hundreds of genomic loci where common genetic variants associate with the risk of cardiac arrhythmias, yet the slow rate of functional assessment severely limits our ability to unlock the unique biology that they identify. Our long-term goal is to systematically link arrhythmia risk loci to their mechanisms, identifying the unexpected mechanisms of arrhythmogenesis, and priming them for therapeutic translation. The key feature of arrhythmia genetic association loci is their non-protein-coding nature, a finding which leads to our overarching hypothesis that transcriptional misregulation underlies much of cardiac arrhythmia risk. To address this hypothesis, we first examine the relationships between known arrhythmia target genes which encode transcription factors and cardiomyocyte electrophysiology using inducible CRISPR-Cas9 modifiers of gene expression. We will seek to understand the transcriptional changes underlying electrophysiological changes by profiling gene expression and protein abundance. At the same time, we recognize that the vast majority of loci remain entirely undefined, a limitation which serves as a great impediment to further translational research. To address this, we will use two orthogonal approaches in human atrial tissue samples. First, our group has led early large-scale implementations of single nucleus RNA sequencing on the human heart, experience which we propose to extend to the goals of this proposal. We aim to link genotype to expression by performing single nucleus RNA sequencing on a large biobank of non-diseased left atrial tissue with available genotypes and clinical metadata. This will provide not only the target gene(s) for the association loci, but also the directionality of effect and the pertinent cell type(s), greatly facilitating downstream validation by our team and others. To complement the direct measurement of genotype to expression, we aim to supplement these analyses with chromatin conformation analysis. While these assays do not resolve the effects of genotype, they measure contact between regions of risk and target promoters to provide putative gene targets. Our preliminary high- resolution contact map from the left atrial lateral wall greatly improved the number of candidate genes for atrial fibrillation association loci. We recognize the importance of anatomically restricted events in the initiation and propagation of arrhythmias, and thus propose to assess the physical proximity between regulatory elements within association loci and their putative gene targets in prospectively sampled atrial tissues using micro-C, a technology which assesses chromatin conformation across the entire genome. Ultimately, accomplishing these aims could prove transformative for facilitating studies of cardiac arrhythmias, unlocking the mechanisms of arrhythmia genetic risk to generate novel therapeutic approaches and guide clinical practices.

NIH Research Projects · FY 2025 · 2023-07

PROJECT SUMMARY Despite the tremendous efforts in Alzheimer’s disease (AD) research, we have not made much progress in understanding the pathophysiology of AD or inhibiting/correcting AD-related behavioral symptoms. The recent FDA-approved aducanumab demonstrated significant efficacy in reducing amyloid β (Aβ). Still, it showed a limited effect in improving AD-related memory impairments. The specific neural circuits that mediate these cognitive processes but are altered progressively in the AD brains may serve as a treatment target after the removal of Aβ plaques. In my previous studies, I demonstrated that dorsal Raphe nucleus (DRN) serotonin (5- HT) neurons provide monosynaptic inputs to the hippocampal ventral CA1 (vCA1). Further, genetic ablation of 5-HT synthesis selectively in these vCA1-projecting DRN neurons impaired spatial memory in young mice. In addition, genetic deletion of the 5-HT 2C receptor (5-HT2CR) in the vCA1 led to spatial memory deficits in young mice. I also observed that lorcaserin, a selective agonist of 5-HT2CR, can ameliorate spatial memory deficits in a 6-month-old knock-in AD mouse model (APPNL-G-F), associated with restoration of synaptic plasticity in vCA1 neurons. Together, I developed a hypothesis that a 5-HTergic DRN to vCA1 circuit regulates spatial memory via 5-HT2CR, a therapeutic target for memory symptoms in Alzheimer’s disease. The K99 phase will focus on the upstream node of this circuit, the vCA1-projecting 5-HT neurons. Fiber photometry experiments will be used to monitor the real-time activity of these vCA1-projecting 5-HT neurons, as well as 5-HT release in the vCA1, corresponding to memory acquisition and retrieval behaviors. The intersectional retrograde chemogenetic approach will be used to further test whether inhibition of the vCA1-projecting 5-HT neurons would inhibit memory function and whether activating these neurons would rescue memory impairments in APPNL-G-F mice and aged mice. During the R00 phase, I will utilize the techniques and the problem-solving experience I acquire from the K99 phase to test the functional significance of the downstream 5-HT2CR-expressing vCA1 neurons. I will use fiber photometry to monitor the activity of 5-HT2CR-expressing vCA1 neurons during the memory test and will use the chemogenetic approach to assess the functional relevance of these neurons in memory function. In addition, I will also test the combination treatment of Aβ-lowering (aducanumab) and 5-HT2CR agonism (lorcaserin) in APPNL-G-F mice and aged mice. The proposed studies will advance our knowledge of the circuitry mechanisms underlying memory function and evaluate the possibility of 5-HT2CR agonism as a novel therapeutic target for AD in combination with Aβ-reducing medications. In addition, the K99 phase will provide an ideal training opportunity to equip me with essential techniques, knowledge, and problem-solving skills. These will prepare me for the R00 phase of research and an independent research career focusing on circuitry mechanisms of different behaviors.

NIH Research Projects · FY 2026 · 2023-01

Project Summary Human cytomegalovirus (HCMV) infects the majority of people in the world and can cause serious disease in immunocompromised patients and neonates. The virus establishes life-long latency in bone marrow cells and disseminates to peripheral organs in quiescently infected monocytes. Antiviral therapy delays virus replication, but does not eliminate infected cells. Virus rebound, resistance, and drug toxicity complicate treatment and create a strong demand for improved therapeutics. We advocate that the suppression of HCMV replication must be in combination with the killing of infected monocytes. We found that HCMV infection of fibroblasts and monocytes rapidly stimulated the activity of heat shock factor (HSF) 1, a stress-responsive transcription factor, in a distinct fashion from canonical activation induced by heat shock (HS). Using a novel tool compound called DTHIB, which has been validated to selectively inhibit HSF1 activity, we found inhibition of HSF1 with DTHIB attenuated HCMV lytic replication and stimulated death of latently infected monocytes. These studies provide the beginnings of a proof-of-concept study that HSF1 antagonists may have the capacity to provide the double “hit” necessary to suppress HCMV replication and eliminate latently infected myeloid cells in a single drug. Thus, our central hypothesis is that inhibition of HSF1 with the tool compound DTHIB will limit both infection and spread within an infected host by concomitantly attenuating HCMV lytic replication in permissive cell types and eliminating latently infected monocytes. The first aim will continue to evaluate the antiviral potential of DTHIB as an inhibitor of HCMV lytic replication by examining the drug efficacy on different HCMV permissive cell types, viral strains, and multiplicities of infection (MOIs). We will also conduct transcriptome (RNA sequencing) analyses and functional studies using DTHIB to identify genes dependent on HCMV-induced HSF1 activity responsible for promoting lytic replication and the impact of DTHIB on the expression of this HCMV- induced, HSF1-dependent gene profile. The second aim will continue to assess the ability of DTHIB to stimulate the death of latently infected monocytes by testing the selective drug toxicity on monocytes infected with different viral strains and at different MOIs. In conjunction, we will perform translatome (polysomal profiling) analyses and functional studies using DTHIB to identify HSF1-dependent genes responsible for promoting the survival of latently infected monocytes. The third aim will assess the in vivo antiviral activity of DTHIB on lytic replication, viral spread, and pathogenesis using a novel murine transplant model with human skin organ, which can simultaneously monitor HCMV replication in human tissue as well as monitor monocyte-mediated HCMV spread to distal sites.

NIH Research Projects · FY 2026 · 2023-01

Modified Project Summary/Abstract Section Disruption of normal glomerular filtration is one of the key causes of end-stage renal disease, leading to the need for renal replacement therapy. Myosin 1e (Myo1e) is a cytoskeletal protein that is highly expressed in the glomerular epithelial cells (podocytes) and is involved in many processes important for podocyte function, such as actin assembly regulation, endocytosis, and regulation of cell adhesion. Mutations in MYO1E are found in patients with chronic kidney disease, highlighting its role in maintaining glomerular filtration barrier. In this project we will examine the role of Myo1e activity in supporting podocyte cytoskeletal organization and normal kidney function and test the hypothesis that activation of Myo1e can help protect podocytes from injury and preserve normal glomerular filtration. In Aim 1 we will analyze how disease-associated mutations affect Myo1e functions and activity using a combination of cell-based and in vitro (biochemical) methods. In Aim 2 we will determine the mechanism of autoinhibition of Myo1e activity. In Aim 3 we will test how Myo1e activity helps maintain podocyte integrity and whether activation of Myo1e will have a protective effect on kidney function.

NIH Research Projects · FY 2025 · 2022-09

PROJECT SUMMARY/ABSTRACT Fibrotic-like dysfunction and extracellular matrix stiffening of the trabecular meshwork (TM) is a hallmark of persistent intraocular pressure elevation in primary open-angle glaucoma. Short-term exposure of healthy TM cells to mechanical insult induces characteristic glaucoma-like pathology, which is recoverable after cessation of insult. In contrast, glaucomatous TM cells retain a pathologic phenotype via a stored mechanical memory despite culture within a soft tissue-like matrix environment. The overall objective of this proposal is to identify how mechanical memory in TM cells is first formed and then stored, and how it contributes to the persistence of glaucomatous cellular dysfunction. We hypothesize that TM cell mechanical memory plays a central role in persistent tissue failure in glaucoma. In Aim 1, we will fully characterize TM cell mechanical memory. Cells “sense” their mechanical environment through mechanotransduction. In Aim 2, we will investigate the role of a key mechanoregulatory transcriptional co-activator Yes-associated protein (YAP) in modulating TM cell mechanical memory. Cells “store” mechanical memory through chromatin remodeling and epigenetic modifications. In Aim 3, we will investigate the role of epigenetic modifications in long-term TM cell mechanical memory retention. We will use our innovative bioengineered primary human TM cell-encapsulated hydrogel and dynamically tune matrix stiffness to test our hypothesis. Our specific aims are: Aim 1: To determine how mechanical memory persistence contributes to glaucomatous TM cell dysfunction. Aim 2: To determine how YAP mechanotransduction contributes to TM cell mechanical memory acquisition and retention. Aim 3: To determine how epigenetic modifications contribute to long-term TM cell mechanical memory retention.

NIH Research Projects · FY 2025 · 2022-09

Project Summary and Relevance The goal of this project is to develop mechanisms by which ordinary proteins can be turned into ligand- activated conformational switches. When naturally-occurring proteins of this type are discovered, their engineering can result in technologies that transform biology. For example, CRISPR-associated protein catalytic activity is switched on by binding of guide RNA, and calmodulin undergoes a large conformational change upon ligating calcium. Developing these proteins into DNA manipulation tools and fluorescent calcium sensors, respectively have revolutionized gene editing and the study of calcium signaling. The current proposal asks the question, “what else is possible if other proteins and enzymes can be made to switch on/off by binding of DNA, RNA, or other ligands?”. The proposed project takes a combined biophysical, computational, and cellular approach to develop a general mechanism for linking protein function to ligand binding. Three families of protein switches will be created. The first is a biosensor that plugs into existing DNA tools (such as aptamers and toehold-mediated strand displacement hairpins) without any modification to the sensor, to detect a DNA or RNA sequence of choice. The output is ratiometric (blue/green) luminescence that can be detected by cell phone camera. The second family employs fibronectin 3 ‘monobodies’ as the input domains and fluorescent proteins as the output domains to provide a ratiometric FRET response, or large increase in fluorescence intensity, when encountering an intracellular target. In the third switch design, the enzymatic activity of a bacterial RNase is turned on by cytomegalovirus (CMV) RNA to kill CMV-infected human cells. This last aim addresses the pressing need of preventing transplant-related CMV disease. Relevance. This study will open the biological activity of the human proteome to potential regulation by binding of nucleic acids, proteins, and small molecules. The modular design allows mixing and matching of different proteins to generate molecules with functionalities not found in nature. Examples include biosensors for pathogens and disease biomarkers, and an enzyme that kills virally-infected human cells while leaving uninfected cells unharmed.

NIH Research Projects · FY 2025 · 2022-09

ABSTRACT Fetal Alcohol Syndrome (FAS) is one of the leading causes of intellectual disability in the United States. The CDC estimates that 0.2-1.5 per 1000 live births are children with FASD, a syndrome characterized by disrupted fetal brain development and postnatal intellectual disability (ID). Disrupted connectivity including altered dendritic structure, axonal pathfinding and white matter tracts are common findings in FAS and are thought to be major contributors to ID. However, the cellular and biological targets of alcohol are diverse and it is not clear whether there are common underlying molecular mechanisms producing these disruptions. Identification of common molecular mechanism(s) would enable a deeper understanding of this disorder, inform studies of genetic susceptibilities and provide molecular targets for neuroprotective strategies. This proposal pursues our finding that acute ethanol (EtOH) exposure disrupts Src kinase activity in embryonic cortical neurons. Src is a critical non-receptor tyrosine kinase that sits at central positions in multiple signaling pathways including the Reelin-Dab1 signaling pathway which controls brain layer formation and dendritogenesis. We found that acute EtOH exposure activates Src and induces phosphorylation of many proteins including Dab1, an essential adaptor protein in the Reelin-signaling pathway. Remarkably, this dramatic increase in phosphorylation is followed by a sustained dephosphorylation response in which the phosphorylation of Reelin effectors including Dab1, Src itself and the actin severing protein n-cofilin return to baseline levels, or below. During the extended dephosphorylation phase, the Reelin-signaling pathway can no longer be activated by in vitro application of its ligand, Reelin. In AIM 1 of this proposal, we will determine whether Reelin-Dab1 silencing occurs in vivo after maternal dosing with EtOH. We will then determine whether genetic deficiency in Src prevents the phosphorylation and dephosphorylation responses. Genetically establishing the critical kinase that initiates the EtOH response in vivo will be essential for future neuroprotective efforts. We and others have shown that Reelin-Dab1 signaling controls Golgi-deployment in the forming dendrite. In AIM 2 we will examine whether Src activation and inactivation disrupts Golgi location and function. Disrupted Golgi function would be expected to impact membrane addition, glycosylation, secretion and appropriate expression of many proteins, with potential long term negative consequences on neuritogenesis and neuronal function. In AIM 3 we will determine whether the EphA3 signaling pathway is similarly disrupted by Src dysregulation. EphA3 is a receptor tyrosine kinase that is required for axonal and white matter tract development. We identified the activation site of EphA3 as a target of EtOH-induced Src dysregulation raising the possibility that EphA3 activation and then silencing may contribute to FASD-related white matter disruptions. Collectively, these studies will determine the contribution of EtOH-dependent Src dysregulation to altered developmental signaling in pathways critical for brain development.

NIH Research Projects · FY 2025 · 2022-09

PROJECT SUMMARY CMV disease is the largest cause of post-transplant patient mortality. After a transplant, patients have to undergo extensive screening and prophylactic therapy in order to prevent reactivation of the virus. In many cases, even if these precautions are taken, the virus will reactivate after the patients finish antiviral therapy. This is due to the virus establishing latency in cells of the myeloid lineage. Because the antivirals target and inhibit virus replication, CMV is very difficult to target in its latent stage due to low levels of replication. This proposal aims to develop molecular tools that have the potential to be used in clinic to prevent CMV-related mortality, by combining the fields of protein and DNA engineering. In the first aim, a CMV detection platform will be developed that combines the techniques of rolling circle amplification and hybridization chain reaction to then turn on a luminescent protein biosensor that can be detected with a cell phone camera. This tool will allow identification of active CMV infection with high sensitivity by performing the one-pot reaction at room temperature with no special equipment for detection other than a cell phone. Patients will be able to self-screen at home using this low-cost alternative to PCR that does not require trained personnel or expensive equipment. In the second aim, DNA self-assembly technique of toehold-dependent strand displacement will be utilized to trigger a toxic protein switch in response to CMV-specific RNA input. The components will be introduced into a population of cells that may be latently infected with CMV, and the switch will turn on in response to a latency-associated CMV RNA that is expressed in target cells. This will cause specific death of CMV-infected cells. The potential application of this switch is its use in bone marrow transplants—the switch may be introduced in the cells of donor bone marrow, and any infected cells can be killed before transplantation into the recipient. Development of DNA/RNA-activated protein switches have been limited to natural cas proteins so far. There is a strong desire for the discovery of more cas proteins to extend the toolbox of CRISPR. The techniques developed in this proposal will circumvents that need by “CRISPR-izing” proteins of choice to perform any desired function based on a nucleic acid input. In aim 1 of this proposal, an RNA-activated luminescent protein switch will be constructed, and in aim 2, an RNA-activated toxic protein. These findings will give rise to a new class of proteins to perform functions unattainable by cas proteins in nature.

NIH Research Projects · FY 2024 · 2022-08

Over the past decade, scientists have accelerated efforts to better understand Alzheimer’s disease (AD). Much progress has been made in revealing the genetic architecture of AD and its common antecedent, mild cognitive impairment (MCI). Yet, some people who incur excessive AD risk remain cognitively normal. Identifying risk factors for cognitive deterioration in dementia can guide novel investigations into mechanisms underlying resilience to AD. The best-available polygenic risk score for AD explains 1.7% of overall liability independent from the leading risk gene, APOE (accounts for 17.4% of the variance in AD), indicating that a massive portion of genetic liability remains unresolved. Genetic risk for cardiovascular disease contributes additional risk for AD, thus a systems-level investigation into how cardiovascular dysfunction interacts with neurobiological mechanisms of cognitive decline is warranted. Toward this end, we developed a transcriptome-imputation method—the Brain Gene Expression and Network Imputation Engine (BrainGENIE)—to measure the brain transcriptome in living individuals using blood-based gene-expression profiles. BrainGENIE is fundamentally different from other transcriptome-imputation methods, and captures a much larger proportion of the variance in the brain transcriptome. BrainGENIE can predict 9–57% of the brain transcriptome, yielding an approximate 1.8-fold increase in coverage relative to the prior “gold standard” method PrediXcan, and which greatly improves our statistical power to detect genes and pathways associated with disease. We have also generalized our BrainGENIE framework to impute cardiac-specific transcriptome profiles (HeartGENIE), thereby allowing us to investigate brain- and cardiac-specific transcriptome signatures associated with cognitive deterioration in dementia. Our proposal contains three Specific Aims to improve our transcriptome-imputation methods, reveal gene networks and biological pathways in brain and cardiac tissue underlying cognitive impairment in dementia, and accurately predict an individual’s longitudinal cognitive decline pave the way to precisely define individuals who are at risk for or resilient to AD. Aim 1: Optimize our BrainGENIE and HeartGENIE algorithms to improve the accuracy of predicted gene-expression levels for transcripts in the brain and cardiac tissue that are not currently well predicted. Aim 2: Identify transcriptomic signatures of cognitive impairment in dementia with BrainGENIE and HeartGENIE. Aim 3: Develop an neural network to accurately predict cognitive decline longitudinally. This project will identify reveal multivariate risk factors potentially driving cognitive decline, a critical step toward improving diagnosis, intervention, and prevention of AD.

NIH Research Projects · FY 2025 · 2022-07

Project Summary/Abstract The microbiome affects many aspects of human health and has been linked to diseases such as obesity, inflammatory bowel disease, diabetes, and allergy. The balance between host and commensal bacteria is well maintained in most healthy individuals. One host factor that contributes to intestinal homeostasis is antibody of the IgA subclass. Plasma cells that produce IgA are found in mucosal tissues such as the lamina propria of the gut, but they can also be found in systemic sites including the bone marrow. However, high levels of bone marrow IgA are only found in the presence of certain consortia of bacteria. Increased frequencies of bone marrow IgA-secreting plasma cells are associated with increased concentration of serum IgA that has been shown to be protective in a sepsis model of polymicrobial dissemination. The mechanisms by which bacteria induce systemic IgA responses are unknown. The main goal of this proposal is to take an unbiased approach to defining gene-level mechanisms used by commensal bacteria to induce systemic IgA. Additionally, we will examine how inter-species interactions contribute to systemic IgA specificity. Together, this proposal will provide a framework for understanding how systemic antibody responses are induced in response to commensal bacteria. This understanding could lead to novel therapies aimed at maintaining intestinal homeostasis or using commensal bacteria as a vaccine delivery system. This proposal will support the overall vision of our research program to understand the complex interplay at the interface of bacteria and host by deciphering gene-level mechanisms used by bacteria to induce IgA responses.

NIH Research Projects · FY 2026 · 2022-05

Project Summary The ability to generate immature neurons from neural stem cells is blunted in the brains of people with schizophrenia compared to controls. In this grant, we will determine, at the resolution of single cells, how the transcriptional profile of neurogenic cells is altered in schizophrenia in order to identify at which stage neurogenesis is blocked. Bulk RNA sequencing has identified that the most significantly changed transcript within the neurogenic niche in people with schizophrenia is the general macrophage marker, CD163. We will determine if macrophages in the neurogenic niche have the characteristics of helpful or harmful immune cells, and if the type of macrophage varies either with diagnosis (schizophrenia compared to controls) or based on the extent of local inflammation (high compared to low cytokines). We aim to gather evidence to support or negate possible monocyte migration routes across the blood-brain barrier (BBB). We will determine if brain macrophages have morphological features and molecular signatures consistent with differentiation into microglial-like cells, and if this varies with diagnosis. Lastly, we will determine if markers of adult neurogenesis are changed by inflammation and how glia cells may be changed by inflammation and/or by the presence of increased macrophages. By exploring the nature and transcriptomic state of different cell populations in the human neurogenic niche, we can better develop strategies to restore neurogenesis in schizophrenia and other neurological conditions, possibly through targeting macrophages.

NIH Research Projects · FY 2026 · 2022-05

PROJECT SUMMARY/ABSTRACT This proposal represents a highly innovative line of research focused on understanding the mechanism/s by which PHF21B (plant homeodomain finger protein 21B) deficiency impairs social memory. Social impairments, which may be present in multiple psychiatric disorders, are characterized by deficiencies in social functioning. Social cognitive impairments are a central feature of several neurodegenerative, neuropsychiatric, and neurodevelopmental disorders, such as autism spectrum and attention deficit hyperactivity disorder. They also frequently occur following acute brain damage after traumatic brain injury and stroke. We present conceptually novel evidence showing that PHF21B deficiency significantly impairs social memory. In the three-chamber social interaction test, the social preference index of the PHF21B deficient mice did not significantly differ, but they spent more time interacting with the new stranger than with the familiar stranger compared to wild-type mice. Therefore, their social novelty index was significantly greater than wild-type animals, suggesting social memory deficits. Social memory impairments were further confirmed using the 5-trial social memory test. Our new data also support the concept that PHF21B binds to the epigenetic marker tri-methylated Lys36 at histone H3 (H3K36me3), a histone marker associated with expressed gene bodies and recruits proteins implicated in transcription, splicing, and DNA repair. The proposed studies will interrogate the specific role(s) of PHF21B in neuronal function relevant to social behaviors, specifically in social recognition impairment. Expected outcomes are to characterize the role of PHF21B in the hippocampus and identify its target genes and regulatory mechanisms relevant to social memory. We expect that the proposed studies will provide novel insights into the cellular and molecular mechanisms underlying epigenetic changes that affect social recognition memory. The results to be generated by this project have translational potential as they may facilitate the development of novel pharmacological targets for social memory deficits.

NIH Research Projects · FY 2026 · 2022-04

PROJECT SUMMARY V-ATPases are versatile, highly conserved, multi-subunit proton pumps responsible for organelle acidification in virtually all eukaryotic cells. Complete loss of V-ATPase activity is lethal in all eukaryotes except fungi, but mutations in subunit isoforms are linked to distal renal tubule acidosis, infertility, deafness, and osteopetrosis. V-ATPase activity is subverted in cancer to support additional demands on cellular pH homeostasis and promote metastasis by creating an acidic extracellular environment. Endosomal acidification by V-ATPases also promotes entry of many viruses. There is a crucial need to understand the roles and regulation of V- ATPase subunit isoforms and enzyme subpopulations in order to target of V-ATPases in specific locations therapeutically. V-ATPases are regulated by reversible disassembly of the peripheral V1 subcomplex from the integral membrane Vo subcomplex, and RAVE/Rabconnectin-3 complexes play a critical role in this process. We will investigate the structure, mechanism, and subunit composition of the yeast RAVE and mammalian Rabconnectin-3 complexes, which appear to target specific V-ATPase subunit isoforms as part of their activity. Importantly, mutations in Rabconnectin-3 complexes have been associated with epilepsy and neurodegeneration but the underlying disease mechanism is unclear. We previously demonstrated in yeast that organelle-enriched phosphoinositide phospholipids bind differentially to the two a-subunit isoforms of the Vo subcomplex, providing organelle-specific inputs into V-ATPase localization and activity. Similar lipid interactions are observed with mammalian a-subunit isoforms in vitro, and we will extend these studies to characterizing the effects of the interactions in cultured mammalian cells. Finally, although V-ATPases must function in concert with other cellular mechanisms of pH homeostasis, the underlying mechanisms of this coordination are not understood. We will address this question in yeast, where we have discovered that acute or chronic loss of V-ATPase activity triggers endocytosis of a portion of the major H+ export pump, Pma1, from the plasma membrane. We will determine the mechanism of this vacuole to plasma membrane pH crosstalk. Reduced vacuole/lysosome acidification is an early step in aging in both yeast and mammalian cells. We will assess whether aging yeast cells display a loss in coordinated pH homeostasis or emerging defects in the V- ATPase itself and determine whether these processes can be manipulated.

NIH Research Projects · FY 2026 · 2022-03

Abstract Psychiatric geneticists have discovered hundreds of common single nucleotide polymorphisms (SNPs) associated with schizophrenia (SCZ) through genome-wide association studies (GWAS). Brain expression quantitative trait loci (eQTL) can successfully explain some of those genetic associations. Differences in genetic association between disparate ancestral populations are often reported, however, it is not known whether such population differences originate from different underlying risk genes or from different allele frequencies and linkage disequilibrium of the same risk genes. Our central hypothesis is that genetic regulation of gene expression within brains, as represented by eQTL, can explain the disease GWAS signals. Population structure influences eQTL as it influences GWAS. The major assumption is that the biological foundation of GWAS and eQTL is the S-E-D relationship, short for SNP-Gene Expression-Disorder. Functional interpretation of GWAS signals relies on the discovery of S-E-D relationships. Due to a lack of brain transcriptome data from populations of non-European descent, interpreting SCZ GWAS results for variants uncommon in other populations presents a significant challenge. To discover the causes of these population differences, we will develop a transcriptome dataset of a new brain collection from East Asians (EA, N = 546) and African Americans (AA, N = 450), combined with samples from the existing PsychENCODE project (EA, N = 18). We will also use data of individuals of African ancestry (AA, N = 411) from the PsychENCODE projects. Along with data from individuals of European descent (EU), which dominates the PsychENCODE (N = 1,321) projects, we will have brain transcription data from three major populations worldwide. Our specific aims include: 1) to relate SNPs to gene expression (the S-E portion of the S-E-D networks), we will develop and compare eQTL and coexpression networks of postmortem brains from three populations, EA, AA and EU; 2) to connect SNP-expression to SCZ GWAS signals (the S-E-D aspect), we will use brain eQTL data to explain SCZ GWAS of EA, EU and AA populations and to identify SCZ risk loci that also serve as regulators of brain gene expression; 3) to develop a novel cross-population predixcan algorithm that can infer genetically regulated gene expression, and identify those differentially expressed in patients. The algorithm will be used to re-analyze existing PGC SCZ data and use Vanderbilt University data to replicate the findings. This study will improve the understanding of the genetic contribution of population variation to SCZ risk.

NIH Research Projects · FY 2026 · 2022-02

Project Summary/Abstract Loss of vision has a devastating impact on an individual's quality of life. Most blinding diseases result from loss of neurons in the retina. A promising strategy to treat sight-threatening diseases, is to harness the regenerative potential of cells within the retina. Müller glia (MG), possess an extraordinary capacity in lower vertebrates to regenerate retinal neurons. However, in mammalian retinas, including humans, MG are unable to replace neurons lost to injury or disease. Recently, we have developed strategies to neurogenically reprogram MG in adult mice by overexpressing the transcription factor Ascl1 in MG. Remarkably, the treatment of Ascl1 overexpression, combined with NMDA-induced retinal damage and histone deacetylase (HDAC) inhibition, causes MG to regenerate functional neurons in the adult mammalian retina. While this is significant progress towards realizing the therapeutic potential of MG, only a subset of MG successfully reprogram into neurogenic progenitors while another subset of MG express genes associated with inflammatory processes. We hypothesized that the inflammation that accompanies neuronal cell loss restricts the regenerative potential of MG. Indeed, we recently found that ablation of microglia, the endogenous immune cell of the retina, dramatically improved MG-mediated retinal regeneration. This finding implicates the neuroimmune system as a key component of the regenerative response of the mammalian retina. However, little is known about the neuroimmune interface in retinal repair strategies such as endogenous regeneration. This proposal outlines studies to better understand the neuroimmune axis during MG-mediated retinal regeneration and to develop immunomodulation strategies to improve the regenerative capacity of the mammalian retina. The data generated in this proposal will be foundational to Dr. Todd's ultimate goal of becoming an independent investigator. During the K99 portion, Dr. Todd will expand his technical and theoretical expertise in neuroimmunology to accomplish his aims studying immune-glial interactions during retinal regeneration. New collaborations will be established with investigators in neuroimmunology and further training activities will prepare Dr. Todd to become a successful investigator in the field. The training portion of this proposal will take place at the University of Washington, which offers exceptional access to both research equipment and faculty expertise to assist in the accomplishment of the applicant's goals.