Boston Children'S Hospital

NIH Research Projects · FY 2026 · 2020-08

Project Summary Retinal synaptic remodeling affects visual function and occurs in aging and in age-related macular degeneration (AMD) as well as in retinal injury and detachment. Strengthening retinal neuronal synapse to maintain their normal interaction is important to protect visual function in AMD. The high metabolic demand of retinal neurons, particularly photoreceptors and their synaptic activity, requires abundant energy provided by mitochondria. It is critical to understanding the molecular and metabolic control underlying age-related synaptic remodeling in retinal degeneration, and to finding new ways to repair failing synapse via potentially boosting neuronal energetics. REV-ERBα, a redox-sensing nuclear receptor, may serve in this capacity to regulate age-related photoreceptor synaptic remodeling via modulating mitochondrial metabolism, which is highly relevant for AMD. REV-ERBα is a transcription factor that regulates glucose/lipid metabolism and mitochondrial biogenesis, which can be important processes for photoreceptor synaptic transmission and function. Our preliminary results indicate that genetic deletion of REV-ERBα in mice both systemically or specifically in photoreceptors substantially: 1) accelerated age-related photoreceptor synaptic remodeling, 2) dampened visual function, 3) impaired retinal mitochondrial metabolism; and 4) suppressed key metabolic sensors including LKB1-AMPK axis in the retinas. Based on these findings, we hypothesize that REV-ERBα coordinates metabolic regulation of presynaptic mitochondrial energetics in the photoreceptors, and disruption of REV-ERBα may result in age- related photoreceptor synaptic remodeling and visual dysfunction. Activation of REV-ERBα may strengthen declining synapses as potential AMD therapeutics. We will evaluate this hypothesis with three aims. Aim I: To determine whether REV-ERBα deficiency accelerates age-related photoreceptor synaptic remodeling in mice. Aim II: To determine whether REV-ERBα transcriptionally regulates presynaptic mitochondrial energetics to impact age-related photoreceptor synaptic remodeling. Aim III: To determine whether genetic over-expression and/or pharmacological activation of REV-ERBα may promote photoreceptor synaptic strengthening in aging as potential therapeutics for AMD. This work will uncover a potential role of REV-ERBα as a key metabolic regulator in age-related retinal synaptic remodeling and develop potential new ways to strengthen aging retinal synapse via activating REV-ERBα and thereby protecting retinas in AMD and other retinal injury and degenerative diseases.

NIH Research Projects · FY 2024 · 2020-08

PROJECT SUMMARY/ABSTRACT Pediatric-onset systemic lupus erythematosus (pSLE) carries a high risk of cardiovascular disease mediated by chronic inflammation and premature atherosclerosis, but responsive surrogate outcome measures of cardiovascular (CV) risk are currently lacking. Loss of nocturnal blood pressure (NBP) decline by ambulatory blood pressure monitoring (ABPM) is common in children with pSLE, and has potential as an early, modifiable, non-invasive measure of vascular health. Loss of NBP decline predicts CV events in adults and may be a marker of endothelial dysfunction, which precedes structural changes in atherosclerosis. More importantly, cardiovascular risk associated with NBP decline is potentially reversible with renin-angiotensin-system (RAS) blockade. In order to determine the role of NBP decline as an outcome measure in pSLE, this proposal seeks to first understand which mechanisms of increased cardiovascular risk contribute to loss of NBP decline, and how NBP decline relates to endothelial function or other measures of subclinical atherosclerosis. Responsive outcome measures would enable studies of interventions to improve vascular health. Potential pharmacologic interventions include RAS blockade, which targets endothelial function without increasing infections from immune suppression. There is, however, a paucity of data to guide the use of RAS blockade in pSLE. The objectives of this proposal are to: 1) identify the major factors that contribute to loss of NBP decline in pSLE; 2) determine whether loss of NBP decline is associated with endothelial dysfunction and could serve as a CV risk marker or potential treatment target; and 3) determine whether RAS blockade is associated with a decreased risk of CV events in adolescents or young adults with SLE. We will perform a prospective longitudinal study of children with SLE recruited to undergo serial ABPM, peripheral endothelial function testing and comprehensive vascular profiles. We will also perform a retrospective analysis using advanced pharmacoepidemiologic methods to estimate the effect of RAS blockade on the risk of cardiovascular events among adolescents and adults in a large electronic health record database. K23 Candidate Dr. Chang completed a Master of Science in Clinical Epidemiology at the University of Pennsylvania (UPenn) and has been appointed as an Assistant Professor at the Children’s Hospital of Philadelphia (CHOP). The proposed research and training plan will provide her with the necessary experience conducting prospective patient-oriented research, expand her expertise in non-invasive vascular assessment and cardiovascular outcomes research, and provide advanced training in pharmacoepidemiologic methods, to become an expert in early identification and prevention of cardiovascular complications of child-onset rheumatic disease. She has established a strong multidisciplinary mentoring team that, together with the vast resources at CHOP and UPenn, will facilitate the proposed work and foster her development as an independent investigator and leader at the cross-section of cardiology and pediatric rheumatology.

NIH Research Projects · FY 2024 · 2020-08

PROJECT SUMMARY/ABSTRACT Sickle cell disease (SCD) is a deadly red blood cell (RBC) disorder estimated to affect over 300,000 newborns annually1. In SCD, mutated hemoglobin (HbS) polymerizes2 and causes RBCs to become sickle- shaped. SCD remains prevalent because heterozygous carriers (HbAS) are partially resistance to Plasmodium falciparum malaria3,4, which causes 400,000 deaths annually5. I recently identified HbS polymerization in low oxygen (O2) as the main driver in HbAS resistance to P. falciparum6. This should suggest homozygous HbSS confers greater resistance to malaria, but paradoxically, infected SCD individuals (HbSS) have increased malaria morbidity and mortality7-9. I propose a novel hypothetical model of SCD and malaria interaction in which RBC factors, like fetal hemoglobin (HbF), that create a RBC reservoir in which little to no HbS polymerization occurs, may enable severe malaria. Using a variety of SCD RBC cell types, I will map and model the in vitro growth dynamics of P. falciparum in SCD erythrocytes and identify RBC factors that influence malaria infectivity within this population. This work is foundational in elucidating the molecular mechanisms underlying the interaction between SCD and malaria, and is a major first step in identifying novel treatment targets for severe malaria, SCD, and its comorbidities. I am a pediatric hematologist co-mentored by Dr. Manoj Duraisingh and Dr. Caroline Buckee, both of Harvard's T.H. Chan School of Public Health. My long-term goal is to become an independent physician- scientist investigating the effect of the RBC host on malaria growth and to target such factors therapeutically. My prior research experiences have allowed me to acquire the cellular biology skills to investigate in vitro malaria growth. Through the critical mentored K08 award, I am now well positioned to acquire new skills in mathematical modeling and parasite genetics to better understand the epidemiology of hemoglobinopathies in malaria endemic regions, assess the impact of the introduction of RBC polymorphisms within communities, and find potential therapeutic targets for children with SCD that become infected with malaria. The Boston Children's Hospital and Harvard T.H. Chan School of Public Health are internationally recognized research programs with a number of expert researchers in the areas of hemoglobinopathies, mathematical modeling, and malaria. Boston Children's Hospital, my primary institution, has a distinguished record of training young physician-scientists for leadership roles in pediatric hematology research. I have assembled an excellent scientific advisory committee, consisting of Drs. Higgins, Goldberg, and Sankaran. Drs. Brugnara and Nathan, will continue to serve as my career mentors and guide my research and training experiences. With the structured mentoring, educational, and research plans detailed in this proposal, I will acquire the necessary expertise to become a successful independent investigator with a focus on hemoglobinopathies and malaria.

NIH Research Projects · FY 2024 · 2020-07

SUMMARY MDA5 is a conserved innate immune receptor that detects viral RNAs during infection and activates antiviral immune response. Recent studies have shown that MDA5 can be activated not only during infection, but also under various physiological conditions in the absence of infection. Such “sterile” inflammation can cause pathogenesis of inflammatory disorders, but at the same time, can be therapeutically beneficial, for example during cancer immunotherapies. Over the last few years, my lab has defined the molecular framework for understanding how MDA5 recognizes viral dsRNA and activates downstream signaling. We discovered that MDA5 assembles into filaments upon binding to dsRNA and that the filament formation is required for efficient dsRNA binding and downstream signal activation. Despite the progress, however, there are key gaps in our understanding of how MDA5 is activated and how its activity is regulated. That is, what is the exact identity of dsRNA that stimulates MDA5 both in the virus-infected and sterile inflammatory conditions, and what are the molecular events following MDA5 filament formation leading up to antiviral signal activation. The goal of this proposal is to address these two poorly understood aspects of MDA5 function by focusing on TRIM65, a ubiquitin (Ub) E3 ligase essential for MDA5 signaling. Previous studies from us and others showed that K63-linked polyUb chains (K63-Ubn) plays an important role in MDA5-mediated antiviral signaling. TRIM65 has been speculated to be the E3 ligase responsible for the K63-Ubn conjugation of MDA5. However, whether this is in fact the case, and if so, exactly how and when TRIM65 acts on MDA5 have been unclear. In our preliminary analysis, we found that TRIM65 directly binds MDA5, and this binding is strictly dependent on MDA5 filament formation. This observation suggests that TRIM65 plays a central role as a check-point for ligand discrimination and signal activation. Furthermore, we found that TRIM65 pull-down can be used for specific isolation of MDA5 filament assembled on agonist dsRNA, away from the inactive complexes of MDA5 bound to abundant ssRNAs. This finding promises a novel method for identifying MDA5 ligands, the long-sought-after milestone in the field. Building upon these progresses, we here propose to address two central questions on MDA5 functions, i.e. signaling mechanism (Aim 1) and RNA ligand selectivity (Aim 2), from the new perspective of TRIM65. More specifically, we will determine the structural and biochemical mechanisms by which TRIM65 activates and regulates MDA5 (Aim 1) and develop a novel TRIM65 pull-down strategy to identify the RNA ligands for MDA5. We believe that the proposed work would demonstrate how an E3 ligase can directly participate in the self vs. non-self discrimination and immune signaling processes, and would provide a model for investigating other E3 ligases in immune functions and beyond. Furthermore, our research may also guide new therapeutic strategies to target MDA5 functions and its antiviral signaling pathway.

NIH Research Projects · FY 2026 · 2020-04

This ADRN-CRC application brings together seasoned clinical and laboratory investigators in atopic dermatitis (AD), with expertise in clinical research, immunology, S aureus biology, dermatology, and statistics. The investigators have long track records in implementing multi-center and single-center clinical trials and observational studies in allergic diseases, including AD, to the standards of NIH funded clinical research networks, in conducting NIH fundamental research on disease mechanisms in AD and in training generations of investigators in AD research In part A we demonstrate that we have the personnel and facilities to conduct ADRN network-wide and CRC center-specific research on pediatric and adult AD patient populations recruited from the allergy and dermatology clinics at Boston Children's Hospital and collaborating adult centers at the Brigham and Women's Hospital Mas General Hospital and Boston University Medical Center and Hospital, and from our just completed, as well as ongoing, NIH-funded studies of schoolchildren with allergic diseases. We have a highly experienced team, IRB-approved protocols for recruitment and clinical characterization of AD patients, an infrastructure which includes clinical research facilities, investigational pharmacy services, a laboratory facility capable of processing, storing and shipping human samples, a state-of-the-art immunology research laboratory with a 25 year focus on AD, and a data management facility with quality control plans, and capability to upload data into the NIAID designated repositories and biostatistical support. Project I in part B will draw on an already genotyped local population of AD patients to test the hypothesis that the IL-4Rα R576 polymorphism is associated with increased AD severity and alterations in the function and gene expression of epidermal and immune cells. We will also use a mouse model of AD to test the hypothesis that both epidermal and immune cells contribute to the increased antigen allergic skin inflammation observed in mice with the IL-4Rα R576R polymorphism. Project II in part B will test the hypothesis that S. aureus skin decolonization in AD will reduce disease severity and favorably alter the function and gene expression of epidermal and immune cells that contribute to disease severity. We will also test the hypothesis that S. aureus skin colonization promotes the development of antigen-driven allergic skin inflammation, and its reactivation, using a mouse model of AD. Our proposal will contribute extensively to the ADRN as a Clinical Research Unit and, as an ADRN-CRC will help elucidate the role of genetic and microbial modifiers in AD. !

NIH Research Projects · FY 2026 · 2020-03

Summary My lab’s contributions have helped bring lung biology to the forefront of stem cell biology. Our major focus has been to develop tools to characterize progenitor cells in the adult lung and in lung cancer; I now aim to develop this expertise for applications in lung diseases. We created three-dimensional co-culture organoid systems that have begun to define cell-cell crosstalk between epithelial progenitors and other supporting cell types in the lung. We can now model the formation of airway- and alveolar-like structures from lung progenitor cells, and we have a platform to understand differentiation control at the molecular level. This research program seeks to build on our advances and to further develop lung organoids to interrogate the molecular underpinnings of cell-cell interactions between epithelial progenitor cells and their environment in the adult lung homeostasis and in diseased lung. We will determine the signals through which epithelial progenitors are regulated by mesenchymal cells and endothelial cells during lung injury response and repair. Cells from mouse models of lung disease will be used for single cell RNA-sequencing and in organoid systems to identify cell autonomous and paracrine mechanisms that can be used for therapeutic intervention. We will refine our techniques for use with human lung cells. We will create a lung progenitor cell transplantation assay, a critical need in the lung community for the study of progenitors and for regenerative medicine. While other groups are focused on cataloging lung cell types, our strategies will provide essential tools to interrogate the biological functions of diverse lung cells. Collectively, these new approaches will allow us to continue to build and utilize transformative methods to probe numerous aspects of the biology of normal lung and lung disease.

NIH Research Projects · FY 2025 · 2019-12

Abstract Pseudomonas aeruginosa is an important opportunistic pathogen of humans. It is the principal cause of morbidity and mortality in persons with cystic fibrosis (pwCF), is a major cause of hospital-acquired pneumonia and is particulary problematic in burn wound infections. Hfq is a conserved global post-transcriptional regulator that is required for the virulence of P. aeruginosa. In other organisms Hfq is best known for its ability to promote the base-pairing between small regulatory RNAs (sRNAs) and their target transcripts, with Hfq-promoted interaction between an sRNA and its mRNA target typically functioning to repress target translation. Although approximately 150 different sRNAs are thought to exist in P. aeruginosa, for most of these we understood little about their possible regulatory roles because we did not know which transcripts they targeted. We have recently identified the targets for approximately 90 Hfq-bound sRNAs in P. aeruginosa using an approach called RNA interaction through ligation and sequencing (RIL-seq). These studies revealed that a single sRNA called PhrS largely dominates the RNA-RNA interaction landscape in P. aeruginosa by pairing with close to 800 targets, which is an unusually large number of targets for an sRNA. In Aim 1 we propose to use Ribo-seq to determine which of the many targets of PhrS are controlled at the level of translation by this sRNA. We will also determine whether the extensive target repertoire we observe for PhrS in one of the main laboratory strains of P. aeruginosa is conserved in clinical isolates, where little is known about the regulatory roles of sRNAs. In Aim 2 we propose to determine whether an sRNA called CrcZ, which acts as a molecular decoy for Hfq, functions as a global regulator of sRNA-dependent control in P. aeruginosa. We will also determine whether putative base-pairing interactions we have uncovered between CrcZ and specific sRNAs make them particularly sensitive to the regulatory effects of CrcZ. Our study therefore has the potential to illuminate an additional mechanism through which CrcZ acts. Finally, we have uncovered an sRNA that controls virulence gene expression in P. aeruginosa and influences the ability of the organism to compete with another bacterial species. In Aim 3 we propose to determine how this sRNA exerts its myriad regulatory effects. Our proposed studies might help explain why mutations that abolish production of this sRNA occur in pwCF during the course of an infection. The experiments described in this proposal are expected to reveal how three conserved Hfq-bound sRNAs exert key regulatory effects in P. aeruginosa, and are relevant for understanding post-transciptional control exerted by sRNAs in clinical isolates of this bacterium.

NIH Research Projects · FY 2025 · 2019-09

The adrenal cortex continuously remodels in response to physiological cues, though the precise cellular and molecular mechanisms remain poorly understood. Our prior studies show that the adrenal cortex undergoes zonal transdifferentiation during postnatal development in the zona Glomerulosa (zG) gives rise to the zona Fasciculata (zF). This process involves formation and resolution of multicellular zG-rosettes via the adherens junction(AJ)-aCatenin complex. How these structures regulate aldosterone production and how dysregulation leads to disease is not known. Given that primary aldosteronism (PA), the most common form of endocrine hypertension, involves hyperplasic expansion of zG-rosettes, further study of the factors and signaling pathways involved in regulating zG development and maintenance is warranted. Utilizing a zG-specific b-catenin gain-of- function mouse model, we have shown that zG hyperplasia in PA is driven by a block in rosette resolution/transdifferentiation. In addition, this block involves up regulation of FGFR2 signaling, which is required for rosette formation during normal development. Further, we have found that rosettes act as a coordinating center for Ca2+ signaling, via the AJ-aCatenin complex, and subsequent aldosterone production. We also discovered that WNT2B, recently identified by GWAS analysis as a major risk allele for PA, is a novel regulator of aldosterone production and zG homeostasis. Based on our recent findings, it is increasing evident that further study of the role of AJs, rosettes and the signals that control them is necessary. Thus, we propose the following: Aim 1. Define how WNT2B mediates zG morphogenesis and function. Aim 2. Determine how a-Catenin and AJs mediate zG morphogenesis and function. Aim 3. Establish how FGFR2 regulates zG morphogenesis and function. These studies seek to understand the regulatory mechanisms that control zG function during postnatal development and maintenance. The successful completion of these studies will provide critical insights into the mechanisms that govern zG homeostasis and the initiation and progression of PA, which may lead to new targeted therapies for this disease.

NIH Research Projects · FY 2025 · 2019-09

PROJECT SUMMARY/ABSTRACT Live cell imaging has revolutionized the study of dynamic cellular processes, enabling researchers to gain valuable functional insights that would be impossible to obtain from static images. The recent advances in microscopy technology have made it possible to acquire an unprecedented amount of live cell image data at high spatiotemporal resolutions. However, this abundance of data has brought new challenges, particularly concerning phenotypic and causal heterogeneity. This heterogeneity can complicate the analysis and interpretation of the data, making it challenging to identify critical mechanistic details and understand how cellular processes function in different conditions. To address this issue, we have been developing machine learning platforms that can deconvolve the heterogeneity of live cell images at subcellular and cellular levels. However, there are still many challenges in analyzing live cell heterogeneity in greater detail. First, conventional feature selection/learning that aids in classifying known phenotypes could eliminate biologically meaningful heterogeneity. Second, current cell biology research focuses primarily on mechanisms that produce similar average effects across various populations, which could suffer from causal heterogeneity. Even with the significant progress made in single-cell biology, the discovery of causal mechanisms at the single-cell resolution is still not fully achieved. Finally, the substantial heterogeneity in cell motility and morphodynamics poses a challenge to obtaining integrated and systematic understandings of these processes, despite their clear significance in fields such as tissue regeneration and cancer metastasis. To overcome these challenges, we propose to advance current machine learning methods to i) identify features that preserve subtype heterogeneity while being discriminative between known phenotypes, ii) acquire causal datasets of live cell images by tracking cells before and after optogenetic treatment, and iii) deconvolve the causal heterogeneity of single live cells by integrating time-series modeling and deep learning. We will apply these methods to map out single-cell mechanisms governing cellular motility and morphodynamics of various cell types, which will be valuable resources for the cell biology community. Then, we will characterize how mechanical and metabolic perturbations can shape the heterogeneous landscapes of cell motility and morphodynamics, providing new insights into the underlying mechanisms integrating these processes.

NIH Research Projects · FY 2023 · 2019-09

This  proposal  is  in  response  to  RFA-­DD-­19-­001:  Research  Approaches  to  Improve  the  Care and Outcomes of People Living with Spina Bifida (SB), and we are applying for Component  B:  National  Spina  Bifida  Patient  Registry.  SB  is  the  most  common  permanently  disabling  birth  defect, with an estimated 160,000 people in the United States currently living with this condition.  The care of patients with SB is complex, and requires coordination of a variety of specialists. In  the United States, an estimated 96 clinics provide care for patients with SB. However, there are  differences in interventions and outcomes among clinics. The NSBPR was created to collect and  study a large pool of longitudinal data on interventions, clinical outcomes and the quality of care  of people with SB across various clinics from the US. SB care and research have a long history  at BCH, dating to the late 1970’s when Drs. Alan Retik and Stuart Bauer established the first SB   clinic in New England. Over the ensuing decades, the clinic steadily grew, and in 2012 we were  awarded a competitive internal “Center” designation, resulting in the BCH Center for Spina Bifida   and Spinal Cord Conditions. Because of our relatively large SB population of approximately 800  patients,  our  established  track  record  of  innovative  treatments,  surgeries,  and  diagnostic  procedures,  and  our  demonstrated  commitment  as  a  non-­funded  site  for  last  several  years,  we  propose that the BCH SBC be a funded site in the NSBPR. As a new funded site, the BCH SBC  will achieve the following aims: first, expand the enrollment numbers in the NSBPR and approach  each  eligible  patient  in  our  program.  Specifically,  our  goal  is  to  enroll  and  submit  data  on  600  patients with SB over the next five years. Second, enhance longitudinal data collection on health  status,  clinical  care,  and  outcomes  for  consented  patients  to  the  NSBPR  over  a  five-­year  study  period.  Third,  utilize  NSBPR  data  and  state-­of-­the-­art  clinical  research  methods  to  answer  hypothesis-­driven questions that align with the research priorities of the SB community. Our data  represent  a  significant  portion  of  New  England’s  SB  population,  and  it  will  be  a  valuable  contribution to the NSBPR regarding studying differences in interventions and outcomes among  clinics and determining the best practices for people with SB. In addition, our center will bring new  state-­of-­the-­art  clinical  research  methods  to  address  essential  and  unanswered  research  questions that are relevant to improving our understanding of SB and its management across the  lifespan of individuals with SB.

NIH Research Projects · FY 2024 · 2019-07

Project Summary A patient’s genetic variant must be contextualized against a population-based reference and detailed phenotype to assess its pathogenicity and impact on prognosis, based on the care trajectories and outcomes of other patients with the variant, or similar variants of a particular gene. However, CTSA researchers do not have ready access to a definitive and representative reference dataset linking the genome to diagnosis, clinical progression, therapeutic response, and precision-adjusted laboratory reference ranges with the appropriate consents to recontact patients if needed. In preliminary work, three of the leading children’s hospitals in the CTSA program formed the Genomics Research and Innovation Network (GRIN) leveraging a combined, ethnically diverse population with unparalleled representation across the pediatric disease spectrum. GRIN sites broadly consent patients into compatible biobanking protocols. The next logical step is a truly federated CTSA-wide biobanking initiative, with the informatics supporting a Genomics Information Commons (GIC). With phenotype data produced as a byproduct of care, we develop the GIC technology, regulatory, and policy backbone, recognizing both heterogeneity of IT systems across CTSA hospitals and local control imperatives for a successful federated network. First, adhering to well-established common data models, each site exposes data to investigators across the secure PIC-SURE meta application programming interface (API), fostering incorporation of multiple heterogeneous clinical, omics, and environmental datasets. We demonstrate the self-scaling nature of the GIC as two additional CTSAs join in a modular fashion. Second, we develop two portals for researchers: (A) Prep-to- research portal. Investigators can execute genotype, phenotype, or combined genotype/phenotype queries, and receive aggregate results in real time; and (B) Study portal. With proper approvals, patient-level data are readily transferred to a cloud-hosted environment with data science tools (Jupyter Notebooks, R Studio), SMART on FHIR apps and resources, and API access to external data sources (e.g., gnomAD, NHANES). Third, we develop a GIC toolkit with policies for broadly consented biobank enrollment, investigator access, material transfer, and collaboration to enable new sites to participate and/or self-organize into collaboration networks. Finally, we leverage the GIC to build, and make publicly available, a knowledge resource of genetically-adjusted, precision laboratory reference ranges across demographically diverse populations.

NIH Research Projects · FY 2026 · 2019-07

Abstract During development, cells adhere to specific partners in precise arrangements to build well-ordered structures. Nowhere is this more impressive than in the brain, which has the most diverse cell types with the most elaborate morphologies and most highly specific connectivity of any organ. While extensive work has been done to identify mechanisms of partner selection among neurons, far less is known about neuron-glia pairing. Glia extend membranous processes that intimately wrap specific synapses, affecting synapse growth and pruning, and modulating synapse strength during learning. Defects in glia-neuron interactions are associated with a host of neurodevelopmental disorders. Thus, understanding how specific neuron-glia attachments are determined will shed light on a key aspect of brain wiring, and will reveal general principles by which cells select specific adhesion partners during development. This project uses a single defined neuron-glia attachment as a model to identify the developmental and genetic mechanisms that underlie neuron-glia pairing. It focuses on a single C. elegans sensory neuron, called URX, that forms membranous attachments to a specific glial partner, the lateral ILso glial cell. Highly cell-type-specific drivers allow this single, defined neuron-glia contact to be visualized or genetically manipulated in live intact animals. Preliminary data show that this specific neuron-glia attachment arises in embryos by a multi-step developmental process. First, the URX dendrite anchors to a 'guidepost' glial cell during embryo elongation, positioning the dendrite ending at the nose tip. Then, a sensory cilium grows out of the dendrite tip to form the elaborate attachment to the ILso glial partner. This project will investigate: Aim 1. How does the dendrite anchor to the guidepost cell? Preliminary data suggest that epithelial adherens junctions are modified to create the anchoring site. Aim 2. How does the sensory cilium mediate neuron-glia adhesion? Preliminary genetic screens have identified several mutants that disrupt cilia adhesion, including one that affects a proteoglycan with homology to a protein that mediates glia-synapse interactions in mammalian brain. Aim 3. What is the function of this highly specific neuron-glia attachment? Preliminary work indicates that the attachment undergoes experience-dependent remodeling, suggesting a mechanism by which glia could tune the sensitivity of the neuron by altering the physical structure of its receptive ending.

NIH Research Projects · FY 2024 · 2019-07

Stress Hydrocortisone In Pediatric Septic Shock (SHIPSS) Project Summary Sepsis represents the most common cause of childhood mortality worldwide. In the United States alone, 200 cases of pediatric sepsis are diagnosed each day, with an associated hospital mortality rate of 5-10% and health care expenditures now approaching $5 billion annually. Moreover, nearly 40% of children admitted to pediatric intensive care units (PICUs) for septic shock have not regained their baseline health-related quality of life one year following the sepsis event. During early resuscitation of the child with septic shock, in addition to antibiotics, volume replacement, and vasoactive-inotropic support, the most recent pediatric treatment guidelines advise the practitioner to consider adjunctive hydrocortisone therapy if the patient “is at risk of absolute adrenal insufficiency or adrenal pituitary axis failure”. However, the potential benefits and risks of this recommendation have not been rigorously examined. On the one hand, corticosteroids are inexpensive and have been frequently demonstrated to improve hemodynamic status in children and adults with sepsis. Conversely, this drug class is known to alter transcription of approximately 30% of the human genome. Notably, corticosteroids down regulate most aspects of the immune response, but particularly adaptive immunity. Moreover, recent data suggests that children with particular gene expression profiles in sepsis have increased likelihood of mortality when treated with corticosteroids. SHIPSS (Stress Hydrocortisone In Pediatric Septic Shock) is a prospective, randomized, double-blinded, placebo-controlled trial examining the potential benefits and risks of adjunctive hydrocortisone prescribed to critically ill children with fluid and vasoactive-inotropic refractory septic shock. Up to 1,032 children will be enrolled, randomized, and evaluated at baseline, PICU discharge, and 28 and 90 days following study enrollment/randomization. The primary hypothesis is that hydrocortisone, compared to placebo, will decrease the proportion of subjects with poor outcomes, defined as death or severely impaired (≥25% decrease from baseline) health-related quality of life. We will also follow subjects to detect side effects of the treatment. Finally, we will test the hypothesis that biomarker-based prognostic and predictive enrichment strategies can improve our ability to identify which children with septic shock are more likely to benefit from adjunctive hydrocortisone, and which may be harmed. This randomized control trial will have a significant impact on public health by providing the heretofore missing evidence to inform guidelines regarding therapy for septic shock in children.

NIH Research Projects · FY 2026 · 2019-05

Pain is a very common clinical problem, causing suffering in millions. Treatment of pain that lasts longer than a brief procedure can be difficult and can entail the use of opioids, with their side effects and potential for addiction and diversion. In this research we seek to develop injectable drug delivery systems (DDS) using sustained release technology to provide continuous prolonged local anesthesia (PLA) lasting many hours to days for perioperative pain, or even weeks for chronic pain. In addition, will develop DDS where the patient could determine when they receive local anesthesia, how intense the anesthesia is, and how long it lasts. Those on-demand DDS (termed triggered local anesthetics, TLA) are controlled by external energy sources such as near-infrared light and ultrasound. Both the continuous and triggered DDS have the potential to revolutionize pain management and advance the science of drug delivery. These PLA and TLA systems could mitigate or obviate opioid use. All the DDS should ideally: be delivered by a single injection; be easy to administer; not require general anesthesia or surgery to initiate; last days to weeks; cause minimal local inflammation and no local neuro- or myotoxicity, or systemic toxicity; be fully biodegradable and reversible. Triggerable systems should be easy to use with a safe and convenient device. Our strategy has been to develop novel sustained release vehicles to extend the release of local anesthetics, thus prolonging duration of effect and reducing systemic toxicity. To minimize local (tissue) toxicity we have used site 1 sodium channel blockers (S1SCBs) such as saxitoxin and tetrodotoxin, and taken advantage of interactions with compounds that are known to enhance their duration of nerve blockade, such as conventional local anesthetics and steroids. In PLA, we have greatly extended the duration of effect of our previous designs and reduced their toxicity, such that 3-4 days of nerve block can be achieved without using drug synergy, and at least a week with. In TLA, we have used photo-labile linkages to produce formulations that only release drugs upon photo-triggering (i.e. do not cause nerve block unless the site of injection is irradiated), and where nerve block can be safely and repeatedly re-induced by irradiating the injection site with near-infrared light or ultrasound. This work has produced 17 papers in the past 4 years (actually 3 years if accounting for the lab shutdown due to COVID-19), many in prominent journals (5 in Nature communications, 1 in Nature Biomedical Engineering, 2 in Nano Letters). In PLA, we propose a spectrum of approaches to produce yet longer blocks while improving safety. In TLA, we propose means to extend the number of triggerable events, and extend the time frame over which they can be triggered – allowing use in prolonged perioperative and chronic pain. Addressing these challenges will entail overcoming challenges in biomaterials / drug delivery / nanoscience, including enhancing the loading of highly water-soluble charged drugs into DDS, minimizing their initial rapid (“burst”) release, extending their duration of release, and /or minimizing their baseline (un-triggered) release. The impact of these new approaches on tissue reaction will be studied. The PLA and TLA systems to be developed here address unmet clinical needs and could revolutionize pain management.

NIH Research Projects · FY 2026 · 2019-05

Project Summary There is a great need to increase academic physician scientists in Newborn Medicine who will perform high level laboratory, clinical, translational, and health services research to improve our understanding of the pathobiology of developmental diseases, health disparities, and long-term morbidities. The main objective of our training program is to train postdoctoral physician scientists by providing a structured, mentored, intensive research experience to advance our knowledge of developmental diseases and improve short and long-term health outcomes of children. Equally important, this renewal application requests the resources to continue our record of training physician scientists to become future national leaders and mentors. The unique fetal and early postnatal periods of rapid organ growth represent a critical window in which environmental exposures can result in epigenetic changes that underlie the pathogenesis of a multitude of diseases including psychiatric disorders, cancer, obesity, and cardiovascular diseases. There is no other time in the life of a human when even minor medical interventions can have such a profound impact on long term health, underscoring the need to train neonatology physician-scientists who can focus on diseases of this critical developmental stage. The Harvard Neonatal-Perinatal Medicine Training Program has a ~ 50-year history of training physician scientists who now lead national programs in academic neonatology. Historically, most of our graduates (>80%) continue in academic careers whereas the national average has remained ~35%. We have a large pool of outstanding eligible applicants combined with a highly accomplished mentoring faculty in the rich scientific community of Harvard Medical School which allows us to train top candidates in our field. Our 3-year research and career training program broadly focuses in four areas: 1) The study of molecular, cellular, and epigenetic mechanisms of normal development and perinatal injury; 2) Investigation in neonatal genomics to uncover the genetic basis of complex disorders and develop precision medicine-based therapeutic strategies; 3) Clinical studies using bioinformatic approaches, biomarkers science, clinical trials and health outcomes research; and 4) Innovative imaging of the fetus and newborn, including placental function and hemodynamics. A mentoring program and scholarship oversight committee is assembled for each trainee to provide mentoring in scientific and career development. Didactic courses are required for both basic and clinical research training and supplemented with relevant seminars including a course in the responsible conduct of research. Advisory committees of national experts advise on candidate and mentor selection, scholarly progress, and overall programmatic success. Through rigorous world class research training, we are committed to training physician scientists who will move independently into successful careers as investigators and leaders in Neonatal-Perinatal Medicine.

NIH Research Projects · FY 2025 · 2019-03

How do large molecules, including biological therapeutics, reach the cytosol if delivered from outside the cell? Endocytic internalization (e.g., by clathrin-mediated endocytosis or fluid-phase uptake) is the principal route for bringing these molecules into cells, but most internalized cargo remains entrapped until degraded in lysosomes. Establishing potential mechanisms of endosome escape has generated long-standing controversy, largely because of technical limitations that prevent direct detection. Using recently developed 3D imaging modalities, especially lattice light-sheet microscopy (LLSM) and its combination with adaptive optics (AO-LLSM), we have shown that we can observe endosomal damage and repair and link it to events such as endosomal fission and cargo delivery. We will characterize the mechanism(s) of the delivery events and seek ways to regulate the delivery route, with the aim of achieving a full description of how endosomal membrane damage and repair govern endosomal escape. We will develop novel ways to exploit the deep-learning approaches that will be essential for analyzing the huge data sets we now generate (e.g., 3D, diffraction-limited movies of an entire cell in two or three colors at 2 sec intervals for 5 or more minutes). Our long-term goal is to build on mechanistic understanding to work out how to enhance specific release of desired cargo, such as antisense oligonucleotides (ASOs), microRNAs (miRNAs), and small interfering RNAs (siRNAs), or in other circumstances, how to prevent release of deleterious cargo, such as 𝛂-synuclein and lipopolysaccharide (LPS).

NIH Research Projects · FY 2026 · 2019-03

Abstract Bronchopulmonary dysplasia (BPD) is the most common complication of prematurity whose incidence is on the rise associated with the increased survival of extremely preterm infants. The etiology of BPD is multifactorial resulting from prenatal risk factors such as preeclampsia, chorioamnionitis, and perinatal insults including oxygen exposure, infection, and mechanical ventilation. Inflammation is a key pathway underlying the pathogenesis of BPD which can result in significant long-term multisystem morbidities, including adverse neurological outcomes, immune dysregulation with susceptibility to infections, and pulmonary morbidities including asthma and, in some cases, emphysematous changes that persist into adulthood. Thus, BPD is no longer considered a lung disease of the neonatal period, but a complex condition with multiorgan involvement and lifelong consequences. To date, effective treatments are lacking and there is a need to deliver effective strategies for the prevention and management of BPD. Mesenchymal stem/stromal cells (MSCs) are in clinical trials as potential cellular therapy for BPD. We and others have shown that the main therapeutic modality of MSCs resides in their secretome represented by `small' extracellular vesicles (sEVs), an EV subset that includes exosomes. We demonstrated that treatment with purified human MSC-derived sEvs, termed MEx, ameliorated and even reversed core histological and functional outcomes of BPD in several experimental models. In the neonatal hyperoxia (HYRX) murine BPD model, MEx protected other organs from injury including the brain, retina, and the thymus whose architecture was disrupted by HYRX. We demonstrated that MEx localize in the lung and interact with myeloid cells altering their phenotype from proinflammatory to immunosuppressive. Importantly, adoptive transfer of in vitro MEx-educated bone marrow derived myeloid cells, but not naïve cells, restored alveolar architecture, blunted fibrosis and vascular remodeling, and improved exercise capacity. We hypothesize that MEx regulate the immune landscape of the developing lung and promote a distinct macrophage phenotype that, through release of anti-inflammatory cytokines and enhanced efferocytosis of apoptotic cells, resolves tissue inflammation and orchestrates signals to promote lung growth disrupted by HYRX. In this proposal we plan to (1) Elucidate mechanisms by which MEx promote the establishment of the alveolar macrophage niche and development of innate immunity that is disrupted by neonatal HYRX; (2) Explore the functionality of lung myeloid cells instructed by MEx in resolving inflammation and promoting lung development; and (3) Elucidate the effects of neonatal HYRX and MEx treatment on long term immune cell function and susceptibility to airway disease.

NIH Research Projects · FY 2025 · 2019-02

Project Summary Electronic health records contain a wealth of information about patient health status that can be mined for multiple purposes, including clinical research and improved decision-making at the point of care. This information can be represented as structured variables, unstructured text, and images, among other data types. In this work, we develop new models for representing the unstructured text that take advantage of powerful neural models called pre-trained transformers. We propose to make these models usable for much longer texts by adding hierarchical layers to operate over summaries of smaller chunks of text, and shrinking the size of the encoder that operates on smaller chunks. First, we develop a smaller encoder for sentence and paragraph-sized texts, by using a technique called extreme distillation that trains smaller models from the output of larger models. We also propose to pre-train hierarchical models for text, by taking advantage of smaller encoders like that from the first aim. We take advantage of both public and private datasets and experiment with different pre-training tasks and architectures. Our final aim proposes to combine representations learned from text with those from the more mature areas of structured data and images. We design experiments that answer the question of how best to merge these different information sources, and apply them to important clinical classification use cases that are likely to require multiple information sources for accurate performance. Specifically, we address the clinical tasks of predicting injury severity in emergency departments, and predicting diagnosis and prognosis of patients in intensive care units.

NIH Research Projects · FY 2025 · 2018-12

ABSTRACT This research proposal focuses on the complex development of inner ear cells from various embryonic lineages and the challenges of establishing multi-lineage inner ear tissues in vitro. The inability to routinely utilize patient-derived inner ear explants due to their delicate nature prompts a necessity for a unique approach. Thus, the project's long-term objective is to uncover the chemical and physical signals required to cultivate functional inner ear tissue from human pluripotent stem cells (hPSCs) in vitro. Building on past technological advancements, the research will refine a three-stage 3D culture system to create inner ear organoids (IEOs) – a model that successfully generates sensory hair cells, neurons, glia, and mesenchymal cells. The project seeks to overcome current limitations of IEO heterogeneity and free-floating nature, which restrict live-cell imaging applications essential for advancing drug discovery and gene therapy testing. The primary goal is to develop a standardized, reproducible IEO-on-a-chip system that mirrors the human fetal inner ear, comprising sensory epithelia, peri-otic mesenchyme, and neural inputs. The project has three specific goals: 1) refine the production and purification of otic organoid cellular components, 2) decipher the physio-chemical needs for on-chip otic morphogenesis, and 3) establish image-based assays to investigate hair cell function and dysfunction in IEOs-on-chip. We intend to use genomic data from every stage of IEO development and leverage cell-cell communication analysis to enhance otic cell production. Next, we aim to engineer an on-chip microenvironment promoting self-assembly of tubular otic sensory epithelia. Finally, the study plans to establish image-based assays for on-chip assessment of genetic perturbation to hair cell functional maturation using models related to the deafness-blindness disorder Usher Type 1. The successful completion of this project would lead to a first-of-its-kind tissue chip for inner ear research, offering significant value in the development of innovative gene therapies, as well as protective and regenerative drugs. The proposed system shows potential in addressing current research challenges and spurring advancements in understanding and treating hearing and balance-related diseases.

NIH Research Projects · FY 2026 · 2018-12

PROJECT SUMMARY Juvenile idiopathic arthritis (JIA) and rheumatoid arthritis (RA) are inflammatory disease of joints that together affect >1% of the population. Genome-wide association studies (GWAS) have identified >120 non- HLA loci associated with disease risk, each marking a biological pathway confirmed by human population genetics to play a role the pathogenesis of inflammatory arthritis. Unfortunately, pinpointing these mechanisms from GWAS data has proven difficult. GWAS hits mark large segments of DNA, termed haplotypes. Most of these haplotypes contain no SNPs (single nucleotide polymorphisms) or other variants that affect coding, suggesting that most causative polymorphisms are regulatory. Finding regulatory SNPs and the proteins that bind them has proven to be exceptionally difficult, and as a result GWAS in JIA and RA have so far provided limited insight into arthritis biology. In the first cycle of this award, we developed an experimental approach to this problem that allowed us to address this roadblock, identifying pathogenic mechanisms engaged by regulatory variants at TRAF1/C5 and CD28/CTLA4/ICOS. Each solution established a novel pathway not only for arthritis biology but more broadly to mechanisms of immunoregulation, specifically a new feedback loop that limits TNF production and a previously unrecognized role for ICOS in differentiation of T peripheral helper cells. We now propose to use this approach to define new mechanisms of human arthritis mediated through T lymphocytes, testing the hypothesis that common non-coding SNPs uncover novel T cell mechanisms in inflammatory arthritis. Aim I pursues a new variant in the CD28/CTLA4/ICOS that we show regulates not only CTLA4 expression but also Treg abundance; we define the transcription factor that mediates the effect and test whether the impact on Treg abundance is driven through differentiation or stability. Aim II extends these studies first to ANKRD55/IL6ST, a risk locus for both JIA and RA that we implicate in the regulation of CD4+ effector and regulatory T cells; and then more broadly to Tregs, based on a successful massively parallel reporter assay that we will extend using SNP-seq, a novel high-throughput technique developed in the lab that interrogates candidate regulatory variants using enzymatic restriction followed by next- generation sequencing to identify those that bind transcription factors and other regulatory proteins. Together, these studies will extend the successful first cycle of this proposal, leveraging human genetics to define potentially targetable pathways that drive the pathogenesis of JIA and RA.

NIH Research Projects · FY 2026 · 2018-08

SUMMARY Neurons use local translation to preserve the health of axons, dendrites, and synapses that are far from the soma. Local translation allows them to respond to local needs. While studying the local synthesis of PINK1 in axons and dendrites, we discovered that the PINK1 mRNA was transported into axons and dendrites by “hitchhiking” on mitochondria. The association of the PINK1 mRNA with mitochondria was mediated by synaptojanin2 and synaptojanin2 binding protein (SYNJ2BP). Synaptojanin2, like synaptojanin1, is an inositol lipid phosphatase, but also contains a predicted RNA-Recognition Motif (RRM); mutation of the RRM in synaptojanin2 prevents its ability to localize the PINK1 transcript to mitochondria. We know that synaptojanin2 can bind additional mRNA species, not just PINK1, including many for mitochondrial proteins. Thus synaptojanin2 represents an important addition to the roster of mechanisms that can transport neuronal mRNA. We therefore propose to study the broad significance of the synaptojanin2/SYNJ2BP mechanism for mRNA transport in neurons and for the function of neuronal mitochondria. To this end, we have made both mouse and human iPSC lines with mutations in the RRM of synaptojanin2 (SYNJAAA). In AIM 1 we will catalog the neuronal mRNA species bound to the RRM of synaptojanin2 and determine the extent to which it is required for their transport into axons and dendrites. In AIM 2 we will catalog the mRNA present on neuronal mitochondria. We will determine to what extent synaptojanin2 and SYNJ2BP are needed for this localization. We will also catalog the mRNA species present in synaptosomes from control and SYNJAAA mice to determine which presynaptic mRNAs require binding to synaptojanin2 to reach the synapse. In AIM3 we examine the functional consequences of mutations in the RRM of synaptojanin2 for the protein content of synapses. the morphology and functioning of neuronal mitochondria, and the health and survival of neurons.

NIH Research Projects · FY 2025 · 2018-08

SUMMARY – Succinic semialdehyde dehydrogenase deficiency (SSADHD) is a rare genetic disease caused by impaired γ-aminobutyric acid (GABA) neurotransmission. Since SSADHD was first identified in 1983, research has focused on identifying the spectrum of pathogenic ALDH5A1 mutations, understanding the molecular and biochemical bases of disease presentation, and testing promising therapeutics. To date, however, there remain significant knowledge gaps that are barriers to early detection and prognosis of the disease, and to the assessment of the efficacy of novel promising therapeutics. These gaps include a comprehensive description of the natural course of the clinical severity of the disease, an in-depth assessment of the neurophysiology of the disease, and the prognostic value of biochemical markers. We began to address these knowledge gaps four years ago with our currently funded natural history study (NHS) of SSADHD and have already demonstrated significant correlations between age of the patients, severity of the disease, blood biomarkers, and neurophysiological parameters. However, the 4-5 year span of the current study and varying age and clinical severity of the study participants has mostly afforded a cross-sectional perspective on disease progression and the prognostic value of biomarkers. In order to gain the longitudinal insight needed to assess the predictive power of disease markers at study intake on prognosis, a longer follow-up of the participants is needed. The purpose of this application is to extend this natural history study for five years. We propose the following aims: 1) to determine patient-specific changes over time in the clinical severity of SSADHD, 2) to determine patient-specific changes over time in neurophysiological markers known to be dependent on GABA homeostasis, and 3) to determine patient-specific changes over time in biochemical markers known to be abnormal in SSADHD. To accomplish these aims, the study will follow ~70 patients representing ~30% of all known cases worldwide. The project will be led by research teams at three academic institutions and is supported by patient advocacy groups and families from all over the world. The research will provide the clinical and biochemical information needed to predict the natural course of the disease, monitor the success of future therapeutic trials, and provide a strong rationale for adding SSADHD screening to existing NBS panels.

NIH Research Projects · FY 2025 · 2018-07

Systemic lupus erythematosus (SLE) is an incurable autoimmune disease and represents a substantial health problem in the population. Longitudinal studies of patients and murine models of SLE identify development of autoantibodies against new epitopes over time that correlate with increased pathology. The phenomena is referred to as epitope spreading, i.e. development of autoantibodies against determinants other than the initiating self-antigen. While the mechanism underlying epitope spreading remains unclear, we propose that spontaneous activation of a single B cell clone along with T cell help can promote activation and expansion of multiple distinct clones of nai"ve self-reactive B cells in both GC-dependent and -independent sites where they can be positively selected and undergo affinity maturation, compete and differentiate into effector cells leading to epitope spreading. In order to characterize the dynamics of self-reactive B cells arising in GC-dependent and -independent sites in more depth, we developed a novel adoptive transfer model. In this mouse model, donor B cells from WT or genetic mutants are transferred into lupus mice bearing a single BCR specific for nuclear antigen. We found that the self-reactive WT B cells underwent clonal selection and affinity maturation resulting in single WT clones dominating the GC response much like that observed in our previously reported mixed BM chimeras using the same lupus strain. Remarkably, the donor B cells rapidly expanded over 7 divisions in a GC-independent response that was Tlr 7 and MHC II dependent resulting in selection of a novel subset of effector B cells with a DN2-like phenotype observed in lupus patients (CD11c+CD21 lo). Unexpectedly, donor B cells deficient in CD11c failed to compete with WT donor cells and develop into effector B cells. In the current proposal, we will characterize further the events initiating spontaneous escape of B and T cell tolerance in GC-dependent and -independent responses resulting in epitope spreading. Moreover, we will characterize single TCR that provide functional help in co-stimulation of self-reactive B cells and their antigen specificity. Finally, we will track migration of activated donor cells in the splenic white pulp that give rise to self-reactive effector B cells using a novel spacial transcriptomics approach referred to as MERFISH. Two broad aims are proposed: Aim 1. Characterize the developmental kinetics and functional dynamics of self-reactive extra follicular ASCs. Aim 2. Characterize the role of Tfh cells in epitope spreading of GC-dependent and -independent self-reactive B cells.

NIH Research Projects · FY 2026 · 2018-05

Project Summary Clostridioides difficile infection (CDI) is a leading cause of gastrointestinal infections in developed countries, with a quarter million estimated cases and ~30,000 deaths annually in the United States. The threat of CDI has become exacerbated with the emergence and spreading of growing numbers of new hypervirulent strains. The C. difficile toxin B (TcdB) is a major virulence factor responsible for pathogenesis associated with CDI. Hypervirulent strains often express variants of TcdB containing 3-15% sequence variations from the standard TcdB. These sequence differences affect toxin tropism and virulence and poses a major challenge for developing therapeutic antibodies. Our studies during the prior funding period categorized TcdB into 12 subtypes and found that many subtypes do not share the same receptor profile with the standard TcdB. Here our renewal proposal seek to characterize the structure and function of major TcdB variants, aiming to identify their unique receptor and investigate their virulence in vivo (Aim 1), resolve the toxin-receptor complex structure using the co-crystal structural approach and cryo- EM method (Aim 2), and develop and characterize a new generation of pan-neutralizing antibodies against a broad range of TcdB variants (Aim 3). Our studies are built on a long-standing and fruitful collaborations between a structural biology lab (Dr. Rongsheng Jin’s lab at the University of California – Irvine) and a lab focusing on toxin biology and virulence (Dr. Min Dong’s lab at Boston Children’s Hospital). The success of our proposed studies will provide a mechanistic understanding of the specificity and virulence of major TcdB variants associated with epidemic hypervirulent strains and provide novel pan-neutralizing antibodies to address the unmet medical need to treat CDI patients infected with hypervirulent strains.

NIH Research Projects · FY 2025 · 2017-12

Damage to or loss of the peripheral axons of primary sensory neurons is associated with two clinical syndromes: peripheral neuropathic pain and peripheral neuropathy. Treatment for neuropathic pain is typically ineffective or associated with side effects, and there is no treatment for peripheral neuropathy. To remedy this, it is essential that the mechanisms responsible for both are understood and targets identified that could be amenable to development of novel therapeutics. My goal is to dissect out at an individual neuron level the transcriptional and functional changes that occur over time in response to physical axonal injury, ion channel mutations and exposure to neurotoxic cancer chemotherapeutic agents, and explore the extent to which hyperexcitability and axon degeneration are linked. This will involve combinations of several different approaches: correlating single cell profiles and disease related functional changes, identifying disease susceptibility in patient stem derived neurons, high content phenotypic screens, population imaging in intact animals, genetic editing, and interrogation at high temporal and spatial resolution of behavioral surrogates of pain and sensory loss. The project will focus on neuropathic pain due to physical disruption of peripheral sensory axons, small fiber neuropathies due to voltage-gated sodium channel mutations and chemotherapy- induced peripheral neuropathy, and will examine if these syndromes are distinct or part of a spectrum of sensory neuron pathologies with overlapping risk factors and mechanisms.