Johns Hopkins University

NIH Research Projects · FY 2025 · 2023-04

PROJECT SUMMARY Helminth infections, which affect a billion people worldwide, especially in underprivileged counties, lead to the induction of type 2 immune response to promote clearance of the pathogens. Interestingly, this type of immune response is also induced in response to allergens and has been strongly linked to the development of allergic disorders, such as asthma. Thus, type 2 immunity can play a protective or pathogenic role. The formation of CD4+ helper type 2 (Th2) cells is a central feature of adaptive type 2 response, therefore understanding the transcriptional and metabolic mechanisms that govern the formation and function of these cells has the potential to facilitate the development of new therapeutic interventions to promote their protective functions and/or inhibit pathogenic responses with which they are associated. There is growing evidence that lipid metabolism plays a crucial role in Th2 cells, but the exact mechanisms are still poorly understood. To fill this gap in knowledge, we propose to assess the role of fatty acid transport protein 4 (FATP4), which possesses acyl-CoA synthetase (ACS) activity that promotes the activation of free fatty acids for fatty acid oxidation and complex lipid synthesis. Our preliminary data indicate that FATP4 is a novel regulator of Th2 cells as deletion of this protein in T cells resulted in an increase in the basal number of Th2 cells in the mesenteric adipose tissue and colon. Most strikingly, deletion of FATP4 in T cells or IL-5-secreting cells led to increased resistance to a helminth infection, thus establishing FATP4 as a novel regulator of Th2 cells. We hypothesize that the failure to promote fatty acid activation in FATP4-deficient Th2 cells leads to an increase of free fatty acids that can promote the activity of ligand-activated transcription factors, such as PPAR-g to restrain Th2 responses. To test our hypothesis and to fully understand the role of FATP4 in tissue-resident Th2 cells, in Aim 1, we will examine the phenotypic and functional consequences of deleting this enzyme in response to helminth infection and in a food allergy model. This approach will allow us to examine the role of this enzyme in a both protective and pathogenic setting. In Aim 2, we will utilize lipidomics and genome-wide sequencing assays to assess the changes in the intracellular lipid content, transcription, and chromatin accessibility. The interactive analysis of the collected data will allow us to define the molecular mechanism by which FATP4 regulates Th2 cells. Collectively, the result of this work will provide us with an insight into the role of fatty acid metabolism in Th2 cells and has the potential to contribute to the development of novel treatments for illnesses mediated by type 2 immunity.

NIH Research Projects · FY 2026 · 2023-04

How the precise patterns are achieved during development of the human body plan remains obscure due to limited access to human embryos, while elucidating the mechanisms will advance knowledge of human development and contribute to regenerative medicine. The goal of my research is to reconstruct development of the human body axis and appendages using pluripotent stem cells (iPSC) and to illuminate general principles of pattern formation. I have used iPSC to successfully establish two 3D models recapitulating spatiotemporal features of human somite formation, which provide a valuable platform to decode mechanisms of body axis patterning with unprecedented resolution. Using these models, I found that active cell sorting underlies the antero-posterior (AP) polarity patterning of somites and put forward a novel framework explaining the formation of repeated structures along the body axis. In this proposal I will further utilize the in vitro models to expand and refine the cell sorting centered framework of somite AP patterning, as well as develop 3D models of human limb development to set up foundation for my future investigation of digit periodic patterning. In Aim1, I will investigate how cell sorting are coordinated with classical modules of somitogenesis. In the mentored phase, I will uncover roles of the segmentation clock in synchronizing the onset of cell sorting within a forming segment to ensure robust tissue-level patterning. In the independent phase, I will interrogate how somite size control is coordinated with AP pattern formation. Together these will bridge the novel finding of cell sorting with established concepts of somitogenesis. In Aim2, I will elucidate the molecular and cellular mechanisms of cell sorting and shine light on general cell biological principles of pattern formation. In parallel, I will set out to develop organoid models of human limb development using iPSCs. In Aim3, I will combine a preliminary 2D differentiation protocol of Limb bud cells in the Pourquie lab, the expertise in maintaining limb progenitors in vitro of the Tabin lab, and my specialty in 3D organoid culture to build 3D models recapitulating features of limb bud elongation and patterning. The proposed work will strengthen my knowledge of body axis development, equip me with expertise in limb development, and establish groundwork for my future career in elucidating periodic pattern formation during human development. Altogether, this proposal will provide valuable insights into the early development of human body plan and guide complex organ engineering to further dissect mechanisms and treat diseases.

NIH Research Projects · FY 2026 · 2023-04

G-protein coupled receptors (GPCRs) are critical for almost every aspect of animal life. These proteins are embedded in the cell membrane and allow us to sense and respond to light, smells, and taste. GPCRs also control responses in both our central and autonomic nervous systems, and they regulate both inflammation and immunity. GPCRs control cell migration for normal development and during cancer metastasis. Indeed, approximately 34% of FDA-approved drugs target GPCRs. Nonetheless, despite decades of study, many GPCRs have no known function, their ligands remain unidentified, and the pathways through which they elicit distinct cellular responses remain mostly uncharacterized. Here, we propose to take the first steps toward understanding the roles of GPCRs during development in the experimental system of the Drosophila embryo, which has numerous advantages in terms of visual accessibility, an extensive armamentarium of genetic tools, and relatively low cost. We begin with an analysis of the Drosophila GPCR Tre1, which has been implicated in germ cell (GC) navigation and survival, extravasation of immune cell to sites of injury, and polarization of neuroblasts. We have recently reported that non-canonical Hedgehog signaling works through the Tre1 receptor to control GC navigation, resolving a long-standing conflict regarding the role of Hh in this process and revealing a novel pathway downstream of Tre1 activation. In the first aim, we uncover the molecular and cellular mechanisms through which each step of this pathway is mediated – from receptor binding to actin polymerization. We ask if and how other genes that affect GC migration work through this pathway to repel GCs (in the case of the Wunen lipid phosphate phosphatases) or attract GCs (in the case of HMGCoA reductase). Tre1 is also expressed in the forming salivary gland (SG), a tissue that, unlike GCs, migrates as a fully polarized epithelial collective. We ask if Hh signaling and Tre1 also function in the SG for its navigation and we ask if Tre1 function in this tissue complements or antagonizes the function of another GPCR – Mthl5 – which is expressed in the SG at about the same time and that has also been implicated in Hh signaling. Finally, we establish a pipeline to screen all of the GPCRs encoded in the Drosophila genome and expressed in embryos for roles in the development of either GCs or the SG. Our pilot screen has already identified two GPCRs with phenotypes consistent with important functions, one gene with a potential role in GC survival and the other with a potential role in regulating the SG extracellular matrix.

NIH Research Projects · FY 2026 · 2023-04

Project Summary Huntington's disease (HD) is a neurodegenerative disorder that presents with progressive motor, psychiatric, and cognitive symptoms leading to early disability and mortality. Although significant advances have been made in identifying pathogenic pathways and screening of potential drug targets, no treatments to delay the onset or slow the disease progression exist yet. Thus, there is a need for fresh perspectives on the disease pathogenesis to discover novel therapeutic targets and to facilitate treatment development for HD. This proposal’s foundation is rooted in the discovery of impairment of the “glymphatic system” in HD brain. Glymphatic system is a brain-wide perivascular network that facilitates the exchange of interstitial fluid and cerebrospinal fluid and clears waste products from the brain. This drainage system is supported by aquaporin- 4 (AQP4) water channels which present with high density in perivascular astrocytic endfeet membranes: termed AQP4 polarization. AQP4 polarization requires presence of a functional protein complex composed of a key protein, α1-syntrophin (SNTA1). While multiple independent studies have speculated that the glymphatic system may play a role in the clearance of neurodegenerative disease-relevant proteins, there is limited direct evidence available on how this system is altered in HD, and whether its disruption contributes to HD pathology and disease manifestation. We developed a molecular MRI technique, dynamic glucose-enhanced MR imaging. Using this MRItechnique, we discovered that D-glucose clearance is significantly reduced in a mouse model of HD, and glymphatic clearance is impaired prior to brain pathology and motor deficits. We also found that AQP4 loses its polarization in the HD brain and SNTA1 protein levels were reduced in HD brains. Based on these findings, we hypothesize that loss of perivascular AQP4 polarization impairs glymphatic function, consequently preventing mutant HTT clearance and accelerating HD neuropathology and disease progression. Aim 1 is to define whether glymphatic impairment precedes the development of pathology and behavioral deficits in HD mice. Aim 2 is to determine whether loss of perivascular Aqp4 polarization by Snta1 knockdown accelerates HD-like neuropathology and behavioral deficits in HD mice. Aim 3 is to evaluate whether overexpressing Snta1 or combined with Aqp4 improves glymphatic function in HD mice and attenuates mHTT accumulation and rescue HD manifestation. This project will reveal a mechanistic basis for identifying new therapeutics as well as potential biomarkers for HD.

NIH Research Projects · FY 2026 · 2023-04

Project Summary This proposal examines the previously unaddressed role of altered retinoid metabolism in heart failure (HF). We have recently shown that in both idiopathic dilated cardiomyopathy (IDCM) and experimental heart failure (HF) there is up to a 40% decline in the cardiac levels of the vitamin A metabolite and potent hormone, all-trans retinoic acid (ATRA), despite adequate vitamin A. We have also shown that direct administration of ATRA prevents HF, in response to pressure-overload. However, implementing ATRA therapy for HF could face headwinds, given the pleiotropy of ATRA signaling and the limited half-life of ATRA in the circulation. Alternatively, therapeutic specificity might best be achieved by targeting the enzymes of cardiac retinoid metabolism. This proposal addresses 3 critical knowledge gaps in our understanding of the mechanism of ATRA metabolism and its impact on the post-natal heart. 1. The enzymes that are responsible for the metabolism of retinol to retinoic acid in the adult mammalian heart are unknown. We have begun to identify the pertinent enzymes in human stem cell-derived cardiomyocytes (hSC-CMs). We show that Dhrs4 regulates the retinaldehyde pool in human stem-cell-derived cardiomyocytes hSC-CMs. We detail a workflow to validate other candidates, leveraging advances hSC-CMs and human engineered heart tissue (hEHT). 2. The pathophysiological mechanisms of a clinically-pertinent cardiac ATRA insufficiency have not been addressed. Knockout of cellular retinol-binding protein 1 (Crbp1) recapitulates the ATRA decline seen in human IDCM. Herein, we show the ATRA decline is sufficient to cause diastolic dysfunction and slow myofibrillar relaxation kinetics. We evaluate the role of the retinaldehyde reductase Dhrs4 by conditional cardiac knockout in the mouse heart. We test the hypothesis that boosting cardiomyocyte ATRA can prevent or even rescue HF and ameliorate cross-bridge cycling. We propose to manipulate DHRS4 and ATRA levels to identify ATRA-sensitive transcriptional programs in mouse hearts, and hEHT. 3. How pervasive the ATRA decline is across HF etiologies is unknown, though proteomic biosignatures of ischemic cardiomyopathy (ICM) and HF with preserved ejection fraction (HFpEF) are consistent with ATRA decline. Even so, another study has shown increased cardiac ATRA in the setting of advanced coronary heart disease. Identifying suitable cohorts for ATRA homeostasis therapy requires that the magnitude and direction of ATRA changes in HF be quantified across HF etiologies. We will quantify retinoids and retinoid-associated protein multiple etiologies including HF with reduced ejection fraction (HFrEF), HFpEF, ICM, and hypertrophic cardiomyopathy (HCM), using state-of-the-art targeted mass spectrometry assays (LC-MS3, isPRM) and examine their distribution within the heart using MALDI-MS Imaging. Restated, this proposal addresses fundamentally novel cardiobiology of a transcriptional master regulator with translational potential, by leveraging the latest advances in human heart cell engineering, novel mouse models, advanced mass spectrometry techniques, and human HF cohorts.

NIH Research Projects · FY 2026 · 2023-04

PROJECT SUMMARY Cells perform diverse processes, such as cell division, growth, motility, formation of adhesions, and tissue morphogenesis, under a wide range of mechanical environments. Central to these processes are mechanical forces, which may come from outside the cell or be generated internally and which are integrated with signaling pathways to guide the cellular process. The cell's macromolecular cytoskeletal machinery, including the actin- based myosin II motors and actin crosslinking proteins, assemble, function and then disassemble in response to these forces and signaling pathways. This dynamic force-responsive assembly provides self-tuning of the machinery, leading to natural positive and negative feedback and further allows mechanical inputs to be converted into signaling outputs. Using Dictyostelium cells, we discovered that many of these components are pre-assembled in the cytoplasm in the form of mechanoresponsive Contractility Kits (CKs), which allow for highly efficient responses to force inputs. The CKs include myosin II, cortexillin I, IQGAP1, IQGAP2, plus several other proteins that we know of. For this application, substantial published and unpublished data motivate the questions to be answered, and our work extends from Dictyostelium to human proteins and model systems. We begin by leveraging our suite of experimental and modeling platforms, including a new modeling framework called SpringSaLaD, which allows for molecularly motivated, particle-based, stochastic simulations of biochemical processes. Using SpringSaLaD, we are modeling the formation of CKs by drawing upon measured in vivo concentrations, diffusion constants, and in vivo “apparent” KDs. From this model, we have made an initial list of predictions about the features of the CKs, which we will test in Dictyostelium. We will also explore the kinetics of assembly and disassembly of the CKs with and without mechanical force. For assembly, we will determine the molecular basis for force-dependent assembly of the CKs and nonmuscle myosin II bipolar thick filament (BTF), using interference scattering mass spectrometry. For disassembly, we will use magnetic tweezers to measure the compliance within the BTF and then determine how this compliance restricts the activity of the myosin heavy chain kinase (MHCKC for Dictyostelium and PKCzeta for NMIIB). We have also found that the setpoint of mechanosensitive accumulation (mechanoaccumulation) by Dictyostelium myosin II and human NMIIB has an optimum of 20% assembly fraction. Further, NMIIB's setpoint is cell type- and cell cycle stage-specific. We will use the framework we have established to determine the consequences of setpoint positioning on cell behavior, including NMIIB dynamics, cell division, and gene expression. We will incorporate this information into our computational models for myosin II mechanoaccumulation, expanding the models to include the components of the CKs. In sum, this research effort, which spans molecular to cellular scales combined with physical theory development, will decipher key principles and mechanisms of force-dependent cytoskeletal assembly and the impact on cell behavior.

NIH Research Projects · FY 2026 · 2023-04

Summary/Abstract It is estimated that up to 28% of the global burden of disease may be amenable to surgical treatment. The majority of affected individuals live in low- and middle-income countries (LMIC). Globally, an additional 143 million surgical procedures are needed annually to meet the unmet need of surgery, and a failure to expand surgical access to populations in need would result in a total loss in gross-domestic product of 12.3 trillion dollars globally. Africa has one of the highest burdens of untreated surgical problems. Moreover, a large proportion of those without access to adequate surgical care are forcibly displaced persons and refugees who number 82 million and 25 million, respectively. Refugees face double the burden of surgical problems than non-refugee populations in LMICs. The absence of comprehensive training programs in the implementation science of surgery, rehabilitation, and humanitarian health creates a serious impediment to research, evidence-based policy changes, and impactful changes. The proposed 2023-2028 Johns Hopkins University, Tanzania Red Cross Society and Muhimbili University School of Public Health and Social Sciences Education and Mentoring Program On Surgical Work and Rehabilitation in Tanzania (EMPOWER-TZ) will build on the expertise in surgery and rehabilitation, humanitarian health, and health systems of Johns Hopkins, Muhimbili University of Health and Allied Sciences, and the Tanzania Red Cross Society. EMPOWER-TZ will strengthen research capacity to address the burden of surgical disease, short and long term outcomes of surgery, and rehabilitation needs in humanitarian settings within Tanzania. Specifically, we seek to better develop capacity to study post-surgery outcomes across lived experiences and develop capacity and interdisciplinary teams to better study surgery and rehabilitation sciences in humanitarian contexts. Our model will focus on using expertise at JHU to strengthen the capacity within MUHAS, while simultaneously leveraging the vast experience of TRCS in humanitarian health to provide both contextual expertise and hands-on training opportunities in this program. Importantly, the focus areas and execution of this grant will be done in full partnership. The goal is to promote an ethical, sustainable, and impactful collaboration between the three institutions focused on building research capacity to study the implementation science of surgery, rehabilitation, and humanitarian health.

NIH Research Projects · FY 2026 · 2023-03

PROJECT SUMMARY: Each year over 4,000 children undergo tracheotomy and account for more than 20,000 hospitalizations annually most commonly due to acute tracheostomy-associated respiratory infections (TARI). These hospitalizations are most often due to Pseudomonas aeruginosa infection. Efforts to improve the care of children with tracheostomy are challenged by the limited body of evidence on how patient factors, features of P. aeruginosa itself, and the child's immune response impact the risk of recurrent infection. This proposal will address this critical knowledge gap by identifying and characterizing prognostic factors for frequent rehospitalization in children hospitalized for TARI. In this K23 Mentored Career Development Award, Dr. John Morrison will: 1) leverage existing data from a six-center prospective cohort study of children hospitalized for TARI to identify clinical factors associated with recurrent TARI hospitalization; 2) prospectively determine the association of pathogen-specific factors and features of the host immune response with frequency of recurrent TARI hospitalization, and 3) derive a novel prognostic model incorporating clinical and molecular factors to identify patients at increased risk for recurrent TARI hospitalization. Achieving these aims will facilitate Dr. Morrison's long-term goal of leading prognostically-stratified interventional studies aimed at improving outcomes for children with tracheostomy and others affected by frequent respiratory infections. The applicant has dedicated his career to improving the care for children with chronic respiratory failure and other medical complexity as a physician-scientist. He is an Assistant Professor of Pediatrics with the Johns Hopkins University (JHU) School of Medicine at Johns Hopkins All Children's Hospital (JHACH) who seeks a mentored career development award during which he will develop the advanced training, education, and experience to become an independently funded investigator in biomarker-informed prognostic models and risk- stratified clinical trials in children with tracheostomy. This proposal will provide Dr. Morrison with the support needed to advance his career by 1) acquiring knowledge on the development and application of prognostic modeling, 2) developing expertise in conducting biospecimen-based translational research, 3) preparing to conduct a prospective, multicenter study validating a prognostic model and examining therapeutic strategies, and 4) expanding his practical understanding of individual- and system-level factors contributing to recurrent admissions among children with tracheostomy. Dr. Morrison will be supported by the extensive resources of the Institutes for Clinical and Translational Research at JHACH and JHU and has assembled a strong team of mentors with expertise in biomarker discovery, biomarker-informed prognostic modeling, and risk-stratified clinical trials. He will also pursue coursework through the JHU Bloomberg School of Public Health in biostatistics, molecular epidemiology, and clinical trial conduct to complement his experience in the basic and clinical sciences and acquire the skills necessary to transition to independence.

NIH Research Projects · FY 2026 · 2023-03

PROJECT SUMMARY/ ABSTRACT Alterations in the PI3K pathway occur in 40-60% of ER+ breast cancer or AR+ breast cancer, representing the most common genomic alteration in such tumors, and indicating that the PI3K signaling pathway plays an important role in the tumorigenesis of hormone-dependent tumors. There is important bidirectional regulatory crosstalk between PI3K and ER or AR signaling in breast and prostate cancers respectively, leading to tumors that adapt and survive when either single pathway is pharmacologically inhibited. Mechanistically, we demonstrated that PI3K inhibition activates ER activity to drive the growth of in ER+/PIK3CA mutant tumors, through regulation of the histone methyltransferase KMT2D. KMT2D is phosphorylated by the PI3K effectors AKT1/SGK1, which inhibits its recruitment to chromatin and its role as a coactivator at ER target genes in breast cancer. Upon PI3K inhibition, this inhibitory phosphorylation is lost, allowing KMT2D to drive ER-dependent transcription. We hypothesized that KMT2D could be a common mechanism in controlling nuclear hormone receptor function, PI3K pathway crosstalk, and ER and AR luminal cell differentiation in breast and prostate models respectively. Preliminary data have shown that KMT2D is required for ER and AR transcriptional activity upon PI3K inhibition in breast and prostate cancers respectively. Furthermore, KMT2D loss sensitizes cancer cells to PI3K/AKT inhibition in cells, tumors, and patient derived organoids. We now aim to characterize the epigenetic and transcriptional role of KMT2D as a key modulator of AR/ER nuclear receptor activity in cells and organoids using bulk epigenomic and single cell sequencing (Aim 1). We have also identified the lysine methyltransferase SMYD2 as a novel level of regulator of KMT2D and ER/AR activity. We now plan to elucidate the role of SMYD2-catalyzed-mediated methylation on KMT2D activity and cofactor associations in breast and prostate cancer models (Aim 2). Additional preliminary data demonstrate that SMYD2 loss can sensitize tumors further to PI3K/AKT inhibition. To this end, we aim to determine the role that the genetic manipulation or pharmacological inhibition of SMYD2 has in the therapeutic response to PI3K/AKT inhibitors in breast and prostate cancer (Aim 3). Altogether, this proposal is benefiting from i) a multidisciplinary team of collaborators who are experts in breast and prostate cancer research, protein methylation, and epigenetics, ii) unique patient resources and reagents, iii) robust preliminary data propelled by at least of 7 years momentum as a leader in the field of nuclear receptor regulation which will be critical to design new and improved therapies for hormone- dependent tumors.

NIH Research Projects · FY 2026 · 2023-03

Uterine fibroids affect 70-80% of US women, leading to heavy menstrual bleeding, pelvic pain, and infertility. A prominent feature of uterine fibroids is the presence of a structurally dysregulated and fibrotic extracellular matrix. Despite their prevalence and the immense public health burden they cause, non-surgical treatment options are limited. Research from many groups has revealed a role of senescent cells in dysfunctional fibrosis, such as idiopathic pulmonary fibrosis and foreign body fibrosis. In previous research we demonstrated that senescent cells secrete soluble factors that modulate immune cells, resulting in a feed-forward loop that reinforces a Type 3 immune response and cellular senescence in a fibrosis model of the foreign body reaction. In this project we have used cutting-edge single cell RNA sequencing and new computational methods to study senescent and immune cells in uterine fibroids. We observed that extensive numbers of senescent cells were present in human fibroids compared to adjacent uterine tissues which had few, or no, senescent cells. Immunofluorescence staining revealed p16+ cells with a fibroblastic morphology were present in all fibroid tissues evaluated. Furthermore, the senescent cells were associated with macrophages and abnormal vascularity in the fibroids compared to normal tissues. Multi-spectral flow cytometric analysis confirmed changes in macrophage phenotype and increased numbers of T cells in the fibroids, compared to normal myometrium. Notably, preliminary single cell RNA Sequencing (scRNASeq) analysis of fibroid and normal myometrium revealed multiple cell types that exhibited senescent phenotypes, paving the way for further mechanistic analysis of immune-stromal communication associated with fibrosis. Finally, senescent cell numbers in fibroids decreased significantly after fibroids were injected with collagenase in a phase 1 clinical trial, in support of senescent cells as a viable therapeutic target for treatment of fibroids. This research will test the overarching hypothesis that senescent – immune cell interactions regulate and contribute to abnormal vascularity and fibrosis in fibroid development and pathogenesis. We will pursue three specific aims. Aim 1 seeks to characterize the presence, phenotype, and function of senescent cells and their interaction with immune cells in uterine leiomyoma. Experiments in Aim 2 will validate key senescent cell interaction in fibroid development and determine the impact of environmental factors on senescent cells. Aim 3 will evaluate the effect of senolytic drugs on uterine leiomyomas, in vitro and in vivo. Elucidation of key relationships and cell drivers of the dysfunctional fibrosis in fibroids is likely to have a broad impact on the field. Unraveling the cell-cell immune communication networks may explain how myometrial tissues transform to develop into fibroids. Affirmation of the key role of senescent – immune cell interactions in fibroid pathogenesis raises the possibility of new treatments targeting senescent cells as therapy.

NIH Research Projects · FY 2026 · 2023-03

Cerebellar disease makes ordinary movements extraordinarily difficult, often resulting in endpoint errors. For example, damage to lobule VII of the vermis makes saccadic eye movements dysmetric. These symptoms have suggested that the cerebellum monitors ongoing commands and adjusts them, particularly as the movement nears the target. Yet, individual Purkinje cells (P-cells) have firing patterns that are modulated much longer than the movement. Thus, it has been difficult to decode the activities of P-cells, and their downstream nucleus neurons, with respect to computations that are necessary for control of movements. A key to this puzzle is that the inferior olive monitors the output of the cerebellum and returns to it information that appears to encode error [1–4]. This input to the cerebellum organizes P-cells and nucleus neurons into anatomical groups called micro-clusters [5–7]. Cells within a micro-cluster likely have a common feature: they respond similarly to error. Through a collaboration between Shadmehr, Soetedjo, and Kojima, we used this idea to show that in macaques, if P-cells were organized into groups based on their complex spike response to error, then their simple spikes as a population produced a rate coding that predicted parameters of the ongoing movement [8,9]. The result was a new idea: the fundamental computational unit in the cerebellum may not be an individual cell, but a population of cells that share a common preference for error. Here, we propose that P-cells that respond similarly to error are part of a network that exhibits a special property: within this network, the P-cells not only coordinate their firing rates, but also temporally align their spikes, especially during the deceleration phase of movements. That is, P-cells transmit information to the nucleus by modulating their firing rates, and synchronizing their spikes. In our hypothesis, P-cells combine disinhibition with synchronization to signal when the movement should be stopped [10]. To pursue this idea, in 2016 we built a marmoset lab, pioneered techniques to train the animals, and then used silicon probes to record from many neurons simultaneously [10,11]. We then built new tools for precise temporal analysis of cerebellar spikes [12]. Here, we propose to record from P-cells, molecular layer interneurons (MLIs), and nucleus neurons, use their error response to organize cells into populations, and then quantify both firing rates and spike timing during movements. Our proposed experiments have the potential to produce simultaneous recordings of P-cells, MLIs, and nucleus neurons, something that is unprecedented in primates. We will use this neurophysiological approach to test the anatomical basis of our hypothesis, that the inferior olive organizes the cerebellum into cell-assemblies. The data will allow us to determine whether the healthy cerebellum relies on synchronization to encode information, shedding light on conditions such as dysmetria and tremor, pathologies that appear to arise not from mis-modulation of P-cell firing rates, but rather disorganization of spike timing [13–16].

NIH Research Projects · FY 2026 · 2023-03

ABSTRACT/PROJECT SUMMARY Acute kidney injury (AKI) occurs at a high rate in both native kidneys and allografts and has no specific therapy available. Prior studies have established T cell activation and trafficking as an important mechanism that modulate ischemia reperfusion (IR) and nephrotoxic AKI, along with other overlapping immune and non- immune mechanisms. Furthermore, AKI is common in patients treated with immune checkpoint inhibitors targeting cytotoxic T lymphocyte-associated antigen 4 (CTLA4) and programmed cell death receptor 1 (PD1) for multiple cancers. Our preliminary data using RNA sequencing and flow cytometry shows significant expression of novel immune checkpoint molecule, T cell immunoreceptor with Ig and ITIM domains (TIGIT) in T cells from post IR mouse kidney and ischemic human kidney. Recently published data suggest that TIGIT co-inhibitory activity modifies Th1 and Th17 responses, plus regulates Treg suppression activity. Our preliminary data shows that TIGIT expressing T cells in mouse kidney are highly activated and produce proinflammatory cytokines after IR. Importantly, mice lacking TIGIT (TIGIT KO) were protected from AKI in IR and Cisplatin AKI models, suggesting detrimental role for TIGIT during AKI. Therefore, understanding TIGIT-mediated inflammatory response during AKI is critical for developing novel AKI therapy and to mitigate kidney adverse effects of immune checkpoint therapies. The central hypothesis of this proposal is that TIGIT promotes proinflammatory functions of kidney T cells and impairs Treg suppression function. To test this hypothesis, we will (Aim 1) investigate phenotypic, functional and transcriptional effects of TIGIT in mouse kidney T cells using in vitro and in vivo approaches. We will further investigate the functional relationship between TIGIT and its co-signaling partners (CD226, CD155) and other co-inhibitory molecules (PD1, CTLA4) in regulating kidney T cell functions at baseline and during AKI. Additionally (Aim 2), we will test the hypothesis that T cell specific TIGIT activity is the major mechanism that drives AKI and impairs repair process using adoptive transfer approaches, in vivo anti-TIGIT agonist/antagonist antibody effects on AKI outcome in WT and TIGIT KO mice and blocking TIGIT signaling in repair phase after established AKI. Finally (Aim 3), we will investigate functional effects of TIGIT expression in human kidney T cells in patients with renal cell carcinoma and live donor biopsies. We will also evaluate TIGIT expression on T cells isolated from ischemic deceased donor kidney samples and transcriptional effects at single cell level in T cells from live donor kidney. Results from these studies will be the first to provide important information on TIGIT mediated effect in kidney T cell functions, therapeutic potential of targeting TIGIT for AKI treatment and set the stage for future pre-clinical and clinical studies.

NIH Research Projects · FY 2026 · 2023-03

In South Africa (SA), Mycobacterium tuberculosis (TB) is managed within primary care clinics (PCCs), where nurses treat drug-susceptible TB and TB/HIV coinfection with treatment outcomes rivaling the best in the world. A PCC management strategy offers a more convenient, patient-centered, differentiated model of care that integrates TB and HIV treatment within the same setting. A diagnosis of rifampicin-resistant TB (RR-TB), however, upends this model, requiring referral to a hospital-based, physician-led outpatient treatment center. Hospital-based, physician-led models add significant patient-associated costs, with estimates suggesting 81% of RR-TB patients experience catastrophic costs even in a decentralized outpatient model. There is hope, however, to move RR-TB care into PCCs and in many settings this involves nurse-led management. The BringBPaL2Me Trial is a multi-principal investigator, multi-site, cluster randomized, non-inferiority trial (CR-NIT), to compare nurse-led RR-TB treatment in PCCs to standard of care physician-led RR-TB treatment at district hospitals in the provinces of KwaZulu-Natal (KZN), Gauteng (GP) and Eastern Cape (EC), SA. Clusters include 10 PCCs affiliated with 5 decentralized outpatient programs at RR-TB district hospitals (n=50 clusters). We estimate the need to screen 3,800 RR-TB positive patients to enroll 2,944, or 64 RR-TB participants per PCC cluster. We estimate 60-70% will be HIV co-infected. The interclass correlation is 0.024 based on our prior CRT enrolling 3,000 patients in KZN and EC. The non-inferiority margin is set at 5% with the assumption of 90% treatment success in the physician-led arm. Treatment will include either a 6-month RR-TB regimen (i.e., bedaquiline, pretomanid, linezolid and moxifloxacin, or BPaLM) or fluroquinolone-resistant TB (i.e., BPaL) regimen. The BringBPaL2Me primary aim is to conduct a 5-year, analyst and clinical safety review committee blinded, multi- site, CR-NIT to evaluate 1) treatment outcome; 2) safety; and 3) patient associated catastrophic costs with the following hypotheses: 1) Outpatient nurse-led treatment in PCCs will be non-inferior to outpatient physician-led treatment at hospital-based outpatient sites among RR-TB patients, regardless of HIV co-infection, as determined by a successful treatment outcome [H1]; 2) The proportion of severe adverse events (SAEs) identified will not significantly differ by blinded, independent review [H2]; 3) Patient associated catastrophic costs (i.e., costs 20% or more of household income) will be lower in nurse-led treatment [H3]. Our secondary aims include: 1) time to event analysis for a) RR-TB treatment initiation; b) smear/culture conversion; and, as applicable, c) HIV treatment initiation; d) HIV viral suppression; and e) AE and SAE symptom resolution; 2) characterization of provider adherence to guidelines for: a) dosing requirements; b) RR-TB dosing changes based on AE and SAE events; and c) AE and SAE adjuvant medication management strategy; 3) programmatic cost-effectiveness evaluation of PCC management. Bring BPaL2Me has strong multi-PI collaborations with support from the national/provincial department of health teams and a rigorous design to evaluate effectiveness, safety and costs.

NIH Research Projects · FY 2026 · 2023-03

Project Summary The ability to perceive and understand social interactions is crucial to daily life, and characteristically altered in autism. From a brief glance, we can effortlessly recognize whether people are interacting, whether the interaction is cooperative or competitive, and its communicative intent. However, little is known about the neural basis of these abilities. We recently identified a region in the posterior superior temporal sulcus (pSTS) that is selectively engaged when viewing social interactions. This discovery, coupled with novel methodological and modeling advances, creates an opportunity to investigate the neurocomputational underpinnings of social interactions. We will measure fMRI, EEG, and computational modeling responses to both controlled and naturalistic stimuli to investigate the neural basis of social interaction perception and understanding. Our central hypotheses are that the pSTS is a key computational junction between the visual and conceptual representations of a social interaction, and that it extracts these representations via two different computational mechanisms: bottom-up pattern recognition (from visual information in body and motion-selective brain regions) vs. top-down cognitive processes (based on input from the theory of mind network), respectively. Aim 1 will test for a neural hierarchy of social interaction representations from visual primitives to abstract concepts. Using a condition-rich, multimodal fMRI experiment, we will test the working hypothesis that social interactions are processed hierarchically along a ‘third visual pathway’: with social primitives represented in body and motion-selective visual regions, multimodal representations of social interactions in the pSTS, and higher-level social features along the STS and theory of mind network. Aim 2 will identify the direction of information flow across the social interaction network. By combining EEG recordings with our fMRI data from Aim 1, we can investigate the relative timing of information flow across brain regions to determine whether different aspects of a social interaction (from visual to conceptual) are extracted in a bottom-up versus top-down manner. We hypothesize that social interaction detection and goal-compatibility (i.e., cooperation vs. competition) will be coded early in the pSTS via bottom-up information flow from visual regions. In contrast, we hypothesize that other social evaluations will be represented significantly later based on additional input from the theory of mind network. Aim 3 will identify the neural computations underlying social interaction representations. We will compare our neural recordings with bottom- up (discriminative) and top-down (generative) computational models, which directly operationalize the neural computational theories outlined above, to understand the computations carried out across the social interaction brain network. The proposed studies will provide novel insights into the neural computations used to recognize social interactions. Understanding these mechanisms in typically developing adults is an essential first step towards uncovering how these computations are altered in autism.

NIH Research Projects · FY 2026 · 2023-03

Project Summary: Even though Shigella and enterotoxigenic Escherichia coli (ETEC) are the two most important bacterial causes of moderate-to-severe diarrhea in children in developing countries and in international travelers, there are currently no licensed vaccines for these infections. The goal of this application is the development of an injectable combination vaccine to protect from these two bacterial enteric infections. To accomplish this, we developed an ETEC vaccine candidate (MecVax) using the epitope- and structure- based vaccinology platform, MEFA (Multi-Epitope Fusion Antigen) which results in a polyvalent fusion protein with multiple epitopes on a single protein. MecVax includes two proteins, one to stimulate immunity to the colonization factor antigens (CFAs) of ETEC and another to stimulate immunity to the two enterotoxins. The first has epitopes for the seven most common CFAs while the second has epitopes for the heat-labile enterotoxin (LT) and the heat stable enterotoxin (STa). Animals immunized with MecVax develop functional antibodies to the CFAs and the two toxins and are protected when challenged with ETEC. Developing a safe and immunogenic antigen for STa is innovative since this small protein (19AA) is not naturally immunogenic. To extend protection to shigellosis, we developed a MEFA for Shigella which includes epitopes for the different virulence proteins that are common among all strains of Shigella and invasive E. coli. To further extend protection, the Shigella MEFA also includes epitopes for shiga toxins (including shiga toxin producing E coli - STEC). Because this vaccine is based on the virulence proteins which are common to all strains, this MEFA is expected to protect against all Shigella species and serotypes and not be limited by serotype as are the other vaccines which are based solely on the LPS antigen. There is no single animal model which can effectively evaluate the protective immune responses to the MEFA vaccines; thus, we use a combination of assays to determine the immune responses to the MEFA vaccines. Antibody responses in mice quantitate the responses to the specific epitopes in MEFA fusion while we use functional antibody assays to determine if the antibodies block adhesion (for ETEC), invasion (for Shigella) and neutralize toxins (for LT, STa and Shiga toxins). We then determine protection in animal models using a rabbit colonization model (both ETEC and Shigella) and protection against disease in a pig model (for ETEC) and a mouse lethal pulmonary challenge model (for Shigella). Using a combination of these assays and animal models, we will build the preclinical evidence for the combined ETEC-Shigella combination vaccine. The central hypothesis is that unlike current oral vaccine candidates, an injectable Shigella-ETEC MEFA vaccine will stimulate higher serum antibody titers and protect when the subject is most vulnerable and that natural exposure will boost local intestinal immunity. An effective Shigella-ETEC vaccine will prevent hundreds of millions diarrhea clinical cases and save > 200,000 lives annually.

NIH Research Projects · FY 2026 · 2023-03

Project Summary Tissue-resident macrophages (TRMs) play fundamental roles in tissue homeostasis, immunity, and disease. Thus, unlocking their biology is key to gaining a deeper knowledge of many human pathologies. TRMs are unique from other hematopoietic cells, most of which are comparatively short-lived and continually replenished from the bone marrow. Instead, TRMs form from yolk sac and fetal progenitors and persist into adult life through self- renewal. Over time, and with kinetics specific to each tissue, these fetal-derived TRMs are replaced in most tissues by bone marrow-derived monocytes, which may subsequently acquire a similar transcriptional profile to their embryonic-derived counterparts. However, our understanding of universal factors that regulate TRMs across tissues is limited. Cellular metabolism is one such factor that governs the differentiation trajectories of various immune cell subsets, but how it shapes TRM differentiation, persistence, and function has yet to be studied in detail. We previously identified polyamine metabolism, and its role in the synthesis of the amino acid hypusine as a central axis governing macrophage metabolism and activation. We also showed that hypusine synthesis directs the ability of T cells to take on distinct effector fates. These findings illuminated hypusine as a focal coordinator of immune cell fate and effector programs. However, how hypusine contributes to tissue immunity and TRM maintenance remains unknown. The sole protein to contain hypusine is the translation factor eIF5A, in which a conserved lysine is enzymatically converted to hypusine in a two-step process via spermidine. Hypusinated eIF5A promotes the translation of transcripts with specific sequence properties. Our goal in this proposal is to gain deep understanding of TRM biology in homeostasis and disease by addressing hypusine metabolism. Our central hypothesis is that hypusine regulates the differentiation of monocyte-derived cells into TRMs and/or their maintenance in tissues, and that by targeting hypusine we can modulate macrophages to benefit disease. We base this on our published work and striking preliminary data suggesting that hypusine synthesis controls macrophage tissue-residency across multiple organs. Our approach will add new insight into how short-lived precursor cells develop into long-lived TRMs that carry out functions essential for life. Importantly, it will establish if hypusine synthesis is a tractable route to modulate TRMs in contexts where they influence disease, such as with tumor-associated macrophages and cancer. We will test our central hypothesis by, 1) investigating the role of hypusine synthesis in TRM formation and/or maintenance, 2) probing the mechanisms through which hypusine governs macrophage tissue-residency, and 3) examining whether manipulating hypusine synthesis in macrophages benefits anti-tumor immunity.

NIH Research Projects · FY 2026 · 2023-03

SUMMARY Inositol phosphates are critical signaling messengers involved in a wide range of biological pathways in which inositol polyphosphate multikinase (IPMK) functions as a rate limiting enzyme for inositol polyphosphate metabolism. Many laboratories including ours have studied the biology of IPMK mostly in cellular models. IPMK has been implicated in metabolism but its tissue-specific function at the systemic level is poorly understood. IPMK is highly expressed in skeletal muscle, and the levels are increased with exercise and decreased in diabetes. Skeletal muscle is a major contributor to energy homeostasis, therefore, we have developed mouse and cellular models to elucidate metabolic mechanisms of IPMK. We have found that mice in which IPMK is specifically deleted in skeletal muscle (MKO) displayed disrupted nutrient utilization, impaired glucose tolerance and reduced exercise tolerance compared to the control mice. Moreover, global metabolic and biochemical analyses revealed disrupted mitochondrial functions, reduced beta-oxidation and impaired insulin response in ipmk deficient muscle cells. In addition, we found that IPMK regulates the levels of acetylation via histone protein deacetylases, which plays a key role in metabolism. Based on our previous research and preliminary data, we hypothesize that skeletal muscle IPMK plays critical roles in nutrient utilization and energy homeostasis. We propose four specific aims. In Aim 1, we will investigate the in vivo actions of muscle IPMK on fuel utilization at rest and during exercise. In Aim 2, we will examine how muscle IPMK regulates whole-body metabolism and its response to exercise. In Aim 3, we will investigate how IPMK regulates nutrient utilization in myocytes using biochemical, cellular and molecular approaches combined with chemical genetics to modulate IPMK activity. In Aim 4, we will investigate the transcriptional mechanisms by which IPMK modulates energy utilization using biochemical, transcriptomic and bioinformatic approaches. Together, this project is expected to advance the field by filling a critical gap in understanding of the biology of IPMK in energy homeostasis. Our proposed studies will illuminate the key functions of skeletal muscle in metabolism and could potentially lead to the development of new therapies for diabetes, obesity and related diseases.

NIH Research Projects · FY 2026 · 2023-03

Alzheimer’s disease (AD) and related dementias (AD/ADRD) are a public health crisis in the US marked by growing disparities, with African Americans (AAs) two to three times more likely to be diagnosed than non-Hispanic Whites. Efforts to identify modifiable earlier-life risk and protective factors for known midlife risk factors for poor cognitive outcomes in later life are needed to protect the health of middle-aged and older adults. We propose to prospectively examine trajectories of stress exposures from childhood to early midlife as predictors of known midlife risk factors for subsequent AD/ADRD in two primarily (~66%) AA cohorts that are now ages 41-45 and have been followed repeatedly from age 6 to age 32 (2009-2011) by the Johns Hopkins Prevention Intervention Research Center (PIRC). Relevant individual- and community-level stress exposures that occur from early life to middle adulthood include: 1) adverse life circumstances (i.e., extreme poverty, residential instability, crime, incarceration, traumatic events); 2) mental disorders and their symptoms; and 3) poor sleep (e.g., abnormal duration, fragmentation). Additionally, these stress exposures have been linked to other risk factors for AD/ADRD, including obesity, hypertension, and diabetes, by which AAs are disproportionately affected. We aim to determine the extent to which ~35-year trajectories of stress exposures are associated with estimated midlife risk for later-life AD/ADRD, physiological aging (telomere length, p16, methylation age), epigenetic modification, and inflammation, and cognitive performance—all measured in early midlife—and if these associations are moderated by sex, race, and AD/ADRD risk genes. We will also explore how the timing of exposures in the life-course affects these associations, and if other potential moderators (e.g., childhood academic achievement, educational/occupational attainment, alcohol/drug use, conduct problems, social support, perceived control) affect these associations. We will further explore effects of two early-life (ages 6-8) PIRC interventions on midlife study outcomes. To accomplish this, 1,150 PIRC participants will complete two in-home interviews including a cognitive battery and actigraphic sleep assessments, and we will collect biospecimens for genetic and epigenetic material and physiological aging measures. This study is a rare opportunity to clarify links of earlier-life stress exposures with estimated midlife dementia risk, identify subgroups for targeted AD/ADRD prevention, elucidate potential contributors to disparities in AD dementia, and establish a midlife cognitive baseline for future follow-up of these unusually well-characterized longitudinal, primarily AA cohorts.

NIH Research Projects · FY 2026 · 2023-03

Project Summary: Laryngotracheal Stenosis (LTS) is the pathologic narrowing of the larynx, subglottis, and trachea secondary to mucosal injury from prolonged intubation. This narrowing leads to dyspnea, dysphonia, and can rapidly progress to airway compromise. Therapeutic interventions for the management of LTS are limited to serial dilation, tracheal resection, or permanent tracheostomy which further impairs communication. Medical therapies for LTS are limited by our poor understanding of LTS pathogenesis. Improved understanding of the mechanisms promoting LTS is needed to improve treatment of this debilitating disease. Previous investigation has revealed that an intact immune response is critical to the development of LTS. Characterization of the immune response in LTS has demonstrated increased populations of CD4+ T-cells and macrophages. Preliminary studies in a murine LTS model reveal that depletion of the macrophage population attenuates LTS fibrosis, implicating their pathologic role. However, the local immune mediators and cell signaling pathways promoting pathologic macrophages in LTS are unknown. Macrophage activation is regulated through stimulation of Toll-like receptors (TLRs). TLRs are highly conserved receptors recognizing Pathogen or Damage Associated Molecular Patterns (PAMPs/DAMPs) and lead to downstream activation of regulatory proteins controlling phenotype. Using single cell RNA sequencing the PI has demonstrates increased expression of the TLR4-MyD88 signaling pathway in LTS macrophages. Furthermore, we have identified increased expression of the DAMP S100A8/A9 in LTS tissue. S100A8/A9 is a known activator of TLR4-MyD88 signaling, and worsens fibrosis in our murine LTS model. These findings indicate that TLR4-MyD88 signaling pathways in macrophages may be critical to LTS pathogenesis. However, the relationship between S100A8/A9, TLR4-MyD88 signaling, and pathologic macrophages has not been explored in LTS or other fibrotic diseases, and may represent a critical signaling axis driving pathologic fibrosis. For this study, we will elucidate the signaling networks promoting pathologic macrophages in laryngotracheal stenosis. In Aim 1 we will assess effect of S100A8/A9 on macrophage phenotype and function in a murine LTS model, establish that S100A8/A9s profibrotic effect is mediated by macrophages, and identify the key sources of pathologic S100A8/A9 in human LTS and a murine model. In Aim 2, we will demonstrate the critical role of TLR4-MyD88 signaling in promoting pathologic macrophages in LTS, and elucidate the role of IL1β in promoting LTS fibrosis. Finally, in Aim 3 we will assess S100A8/A9 as a candidate biomarker for the development of laryngotracheal stenosis in patients who have had prolonged intubation. Collectively, this application will lead to an in-depth understanding of the cell signaling networks promoting dysregulated macrophage mediated inflammation and subsequent fibrosis in LTS. The identification of key regulatory pathways promoting pathologic macrophages in LTS will serve as the foundation for targeted treatment strategies that attenuate fibrosis.

NIH Research Projects · FY 2026 · 2023-03

SUMMARY Perianal fistulas (PAF) occur in 30-40% of Crohn’s disease patients and their complications lead to a significant impairment in quality of life. Current treatments are effective in less than 50% of cases. The overall objective of this proposed study is to develop a biostimulatory nanofiber-hydrogel composite (NHC) plug to promote tissue healing and to test its efficacy to repair PAF in clinically relevant animal models. Previous work from the Mao and Selaru labs laid the foundation for this study. Specifically, we have established novel rodent and swine models of PAF that faithfully recapitulate the biology of PAF in patients. In parallel, we have developed a first-generation injectable biodegradable nanofiber-hydrogel composite (NHC) from poly(e-caprolactone) (PCL) nanofibers covalently bonded to hyaluronic acid (HA) hydrogel; and demonstrated its ability to deliver adipose stem cells (ADSCs) and repair PAF by conditioning inflammatory responses, permitting host cell infiltration, and facilitating angiogenesis and progressive remodeling. Building on these preliminary results, we plan to engineer a second generation NHC plug with enhanced mechanical strength and integrity as an off-the-shelf device and optimize its biostimulatory activities to induce more favorable cellular responses governing fistula healing. We hypothesize that this NHC plug with structurally, mechanically, and biofunctionally optimized features will effectively promote angiogenesis and soft tissue restoration; and serve as a carrier for ADSCs and ADSC- derived exosomes to further improve the PAF tissue healing. To test this hypothesis and demonstrate its translational potential, we will pursue three specific aims (1) develop a collagen nanofiber-based NHC plug with optimal mechanical properties and porous structure for ease of implantation to support perianal fistula healing, (2) utilize a rat model to evaluate the efficacy for PAF healing when used alone or in conjunction with ADSCs or ADSC-derived exosomes, and elucidate the pro-regenerative mechanism by assessing cell infiltration, angiogenesis, extracellular matrix deposition, and tissue remodeling, and (3) utilize a swine model to demonstrate the synergistic effect in tissue remodeling by combining the optimized NHC plug with ADSC-derived exosomes. This study will deliver a translatable off-the-shelf biomimetic NHC microporous plugs for the delivery of ADSC-derived exosomes capable of promoting soft tissue remodeling and healing for PAF repair.

NIH Research Projects · FY 2026 · 2023-03

Abstract Lupus nephritis (LN) is diagnosed by kidney biopsy in patients with proteinuria > 0.5g/24h, but the presence of proteinuria means that kidney damage has already occurred. It is estimated that 30% of nephrons are permanently lost with each flare of LN. The identification of LN before kidney damage using urine proteomic biomarkers could shift the management strategy of LN to prevention, potentially leading to earlier, more effective, and less toxic treatment. Three specific aims will be addressed in this R01 building on the work of the Hopkins Lupus Cohort (a 35 year, 2855 SLE longitudinal cohort in which patients are followed by protocol every 3 months) and in particular on the urine biomarker discoveries from the NIH RA/SLE Accelerated Medicines Partnership (AMP). Aim 1 - Develop a urine biomarker panel to identify new lupus nephritis BEFORE proteinuria. Previous AMP urine proteomic studies revealed that urinary IL-16, CD163, and neutrophil granule content indicate intrarenal LN activity. These biomarkers will be quantitated in urine samples collected within 3 months before the onset of proteinuria in lupus patients who ultimately were diagnosed with LN by renal biopsy to determine if the biomarkers are elevated compared to patients who do not develop LN. A full urine proteomic profile will also be assessed to discover additional biomarkers that could contribute to a robust panel for predicting onset of LN before proteinuria. Aim 2 - Develop a urine biomarker panel to guide tapering of immunosuppression in treated LN patients. Patients with a histological NIH activity index >2 on repeat biopsy developed a proteinuria flare and increased mortality upon tapering of immunosuppression in one study. Four urinary biomarkers associated with NIH activity index >2 in AMP (IL-16, CD163, Galectin-1, and PRTN3) will be quantitated ( with analysis of 1200 additional urine proteins) in urine samples from 12 LN patients in apparent clinical remission who flared upon tapering immunosuppression versus 12 LN patients who did not flare upon tapering. The most predictive biomarkers will be combined into a 10- plex panel to be validated in a prospective cohort of 60 patients tapering immunosuppression. Aim 3 - Develop a biomarker for detection of early chronic kidney disease (CKD) in LN. Urine proteomic studies on 187 patients enrolled in AMP identified TGF-β-mediated fibrosis and TNF signaling related proteins that may be superior to proteinuria alone in detecting early CKD. These AMP patients will be followed clinically for at least five years to determine the trajectory of their kidney disease and to find differences in urine proteomic (and other omic) profiles between those who maintain stable renal function versus those who do not.

NIH Research Projects · FY 2026 · 2023-03

Molecular testing and targeted therapies have revolutionized cancer care resulting in better outcomes for patients. The number of biomarker-selective clinical trials continues to increase presenting challenges for cancer centers to adapt processes for efficient identification and enrollment of patients to these clinical trials. Furthermore, there is a gap in uptake of molecular testing and clinical trial enrollment for underserved populations. Addressing these challenges plays an important role in ensuring effective care for all patients. The Johns Hopkins Sidney Kimmel Comprehensive Cancer Center is an NCI-designated Comprehensive Cancer Center and one of eight with lead roles in both the NCI Experimental Therapeutics Clinical Trials Network (ETCTN) and NCI National Clinical Trials Network (NCTN). Biomarker-selective studies are a major focus of these two networks. In this R50 Project, Dr. Gaillard will focus on addressing challenges in patient enrollment to biomarker-selective trials. The work will focus on three approaches: (i) development of a molecular registry to improve process of patient identification and determination of patient eligibility at the Center level, (ii) facilitate timely referrals to biomarker-selective trials using an electronic medical record clinical trials alert for eligible patients at the Physician level, and (iii) provide study-eligible patients with timely education on the role of biomarkers in treatment decision making (Patient level). The long term goal of this program is to develop a streamlined conduit for identifying, referring and enrolling patients for personalized medicine trials. Successful development will enhance accrual to NCI-sponsored clinical trials and be translatable to other cancer centers.

NIH Research Projects · FY 2025 · 2023-03

Project Summary/Abstract A major obstacle in diagnosing, understanding, and treating Alzheimer’s Disease (AD) has been its characterization by patterns of tau and beta-amyloid (Aß) pathology, only adequately seen through traditional methods of histological sectioning and staining. To address this, recent efforts following the 2018 framework put forth by the National Institute of Aging (NIA) and the Alzheimer’s Association (AA) have focused on identifying in vivo biomarkers that can be used instead to characterize AD and specifically along a continuum. Measures gleaned from MRI, such as cortical thickness, constitute one category of such biomarkers. While they have been shown to correlate with clinical stage of AD, MRI biomarkers have not been shown to be specific for AD as they have not been able to be linked to AD’s signature patterns of tau/Aß with current computational tools and modeling frameworks. The goal of this project is to address this deficiency with the development and implementation of a multi-modal, multi-scale image registration and analysis platform that will be used to integrate and statistically correlate microscopic pathology data with macroscopic MRI measures of cortical thickness. The Johns Hopkins Brain Resource and AD Research Centers have prepared 2D digital histology images stained for tau (PHF-1) and corresponding 3D MRI of medial temporal lobe (MTL) tissue from control brains and those with intermediate and advanced AD. Individual tau tangles were detected with a convolutional neural network (UNET) based approach trained on a subset of manually annotated histological samples. MRI was manually segmented into regions of the MTL, and cortical thickness will be measured from from generated surface representations of each of these regions. The project’s overall goal will be accomplished through two main aims. First, tau tangle and cortical thickness measures will be co-localized in the coordinate space of the Mai-Paxinos Atlas through the development of a registration algorithm that uses 1) a multi-target model to account for possible distortion in both histology images and MRI, 2) a “Scattering Transform” to capture textural features in histology images that help predict delineations between grey vs. white matter, 3) non-rigid transformation of regional surface representations to those of the Mai-Paxinos Atlas. Second, statistical correlations will be computed between tau tangles and cortical thickness using a hierarchy of “varifold” measures that capture both data values and relative tissue area to account for differences in scale (microscopic vs. macroscopic) and sampling frequency (irregular vs. regular) of these two datasets. Application of these methods to both control and AD brain samples will characterize the correlation of cortical thickness measures to tau tangle density along the clinical continuum of AD and physically in 3D space, within specific regions of the MTL, and along particular axes of the brain. These correlations will characterize the specificity of cortical thickness measures for AD, and the sharing of these methods via an open-source platform will enable this characterization for other MRI biomarkers in the future.

NIH Research Projects · FY 2026 · 2023-02

(<30 lines) . Youth-onset type 2 diabetes (YO-T2D) is increasingly prevalent in parallel with the obesity epidemic, yet effective treatment and prevention strategies are limited. The physiologic increase in insulin resistance occurring during puberty, in combination with obesity-related insulin resistance, enhances the risk of T2D. Yet, it remains unclear why some youth progress through puberty with intact β-cell function, while others do not, despite similar phenotypic and metabolic characteristics. More information is needed regarding the unique events during puberty to better understand 1) the basic pathophysiology of glucose control, insulin sensitivity, β-cell function, and T2D risk in youth, 2) differences among girls and boys, populations at highest risk, and urban and rural geographies, and 3) the potential contribution of other risk factors including psychological, behavioral, and social and external contexts. Importantly, this research needs to address the timeline of pathophysiology and progression from normoglycemia or prediabetes to YO-T2D. The DISCOVERY of Risk Factors for Type 2 Diabetes in Youth (DISCOVERY) study provides a unique opportunity to characterize the risk progression profile and mechanisms underlying the development of YO-T2D, and evaluate the effects of modifiable and non-modifiable risk factors. Ultimately, the results of this study will establish a basic pathophysiology to inform future studies aimed at achieving target glycemia, improving insulin sensitivity, preserving β-cell function, and/or preventing YO-T2D. To address this goal, DISCOVERY will recruit, enroll, and follow a nationally-representative cohort of 3,600 at-risk obese youth in early puberty; extensively phenotype them as they transition through puberty; and characterize the course of decline and dysfunction in pathophysiological indicators that lead to YO-T2D. The expected duration of the DISCOVERY is 5 years, including planning, recruitment, follow-up, analysis, and reporting. In addition, DISCOVERY will store longitudinal biospecimens and genetic material with the intention of acquiring additional ancillary funding to pursue analysis of emerging indicators. Johns Hopkins has experience in multicenter and diabetes-related investigations and will contribute to DISCOVERY through the recruitment of approximately 240 at-risk youth, implementation of the IRB-approved consensus protocol, participation on DISCOVERY committees, and collaboration on the analyses and dissemination of the findings from DISCOVERY.

NIH Research Projects · FY 2026 · 2023-02

PROJECT SUMMARY Of the 400,000 older (age ≥55) adults living with end-stage renal disease (ESRD), 87% are cognitively impaired and 25% are subsequently diagnosed with dementia. Incident dementia in older ESRD patients is associated with a 1.5-fold higher risk of disability and 2-fold higher risk of hospitalization and mortality. Thus, identifying modifiable risk factors for cognitive decline is critical to the field of geriatric nephrology. A highly likely risk factor for cognitive decline and incident dementia is secondary hyperparathyroidism (SHPT), which affects nearly all ESRD patients. SHPT, characterized by high serum parathyroid hormone (PTH), is due to mineral abnormalities in ESRD. While PTH has been associated with cognitive impairment in non-ESRD populations we have found that median PTH levels are 54% higher in ESRD patients with cognitive impairment (p=0.03) and 2-fold higher in those who develop dementia. Furthermore, our preliminary data suggests that PTH increases other SHPT biomarkers, alkaline phosphatase (ALP, r=0.25, p<0.001) and FGF-23 (r=0.27, p=0.01), which also correlates with worse executive function (r=0.64, p=0.01). We hypothesize that PTH likely causes domain-specific cognitive decline both directly by binding to receptors in the brain and indirectly via release of other biomarkers. Yet, we found a paucity of high-quality studies of PTH, novel bio-markers, and cognition among ESRD patients in our systematic review; none evaluated cognitive trajectories. SHPT is modifiable with treatment including poly-pharmacotherapy, surgical parathyroidectomy (PTDx), or waiting until kidney transplant (KT) to reverse the etiology of SHPT. However, current SHPT treatment guidelines are inconsistent and ignore cognitive sequelae mainly due to the paucity of high-quality studies characterizing the impact of SHPT on cognitive function. Understanding the impact of SHPT on cognitive trajectories will allow for tailored treatment to mitigate cognitive decline, associated morbidity, and improve shared treatment decision- making among patients and treating surgeons, geriatricians, and nephrologists. Therefore, our central hypothesis is that SHPT contributes to cognitive decline and incident dementia in older ESRD patients and can be modified with treatment. This proposal will leverage and expand the scope of the oldest existing NIA-funded longitudinal cohort study of cognition and frailty among KT patients (3,062 SHPT patients) and prospectively enroll an additional 600 older SHPT patients in an ancillary study, in which, we will perform assessments of novel SHPT biomarkers and longitudinal, comprehensive assessments with a new neurocognitive battery to identify specific cognitive domains directly related to SHPT. We aim to: 1) To quantify the association between PTH and domain-specific cognitive trajectories among older SHPT patients 2) To test whether SHPT treatments impact cognitive outcomes, and 3) To develop a decision-making tool surrounding personalized SHPT treatment to mitigate cognitive decline. Novel incorporation of cognitive trajectories and SHPT biomarkers will transform practice and improve treatment decision-making in older ESRD patients.