University Of Colorado Denver

NIH Research Projects · FY 2026 · 2026-04

Project Summary This focused research proposal fills 2 very specific gaps regarding the research tools that are available to help us better understand the rare and highly morbid brain tumor, Adamantinomatous Craniopharyngioma (ACP). Through our leadership of a unique research group, Advancing Treatment for Pediatric Craniopharyngioma, our laboratory has a considerable tissue resource, which we have used to derive unique Patient Derived Organoid (PDO) and Patient Derived Xenograft (PDX) models. These are critical tools for preclinical research that the ACP community has previously lacked, and in this proposal, we will make specific refinements to these models, allowing them to be used in the design of clinical trials for children and adults with ACP.

NIH Research Projects · FY 2026 · 2026-04

PROJECT SUMMARY/ABSTRACT Measuring the functional connectivity between cortical neurons in the primary visual cortex (V1) remains a pivotal challenge in neuroscience, particularly in understanding how selective visual responses emerge from myriad synaptic inputs. This proposal aims to identify the principles of functional connectivity within layer 2/3 of ferret V1, building upon previous work in mouse and classical work in carnivores and primates. Our central hypothesis posits that inter-columnar connections, following the functional similarity principles observed in mouse V1, are essential for feature selectivity. We propose two main aims. First, using all-optical interrogation, we will perturb and map excitatory and inhibitory neuronal interactions within and between orientation columns, testing hypotheses about the spatial profile of excitatory connectivity, the functional specificity of inhibitory interneurons, and the dynamic recruitment of functional connections. Second, we will employ two-photon calcium imaging to map and analyze the organization and integration of synaptic inputs on the dendritic tree during diverse visual stimuli presentations. These studies will assess the functional similarity of long-range excitatory inputs and their preferential location on distal dendritic tufts, as well as the dynamic recruitment of inputs in shaping somatic responses. Through these approaches, our research aims to uncover novel computational circuit motifs in ferret V1, advancing our understanding of cortical circuits and informing the development of brain-inspired artificial intelligence.

NIH Research Projects · FY 2026 · 2026-04

PROJECT SUMMARY / ABSTRACT Methadone is a highly effective medication for opioid use disorder (OUD) treatment. When taken regularly, it is associated with a 50% mortality reduction. Unfortunately, less than 5% of the estimated 7.6 million individuals with OUD receive methadone treatment. Hospitalization is a touch point to initiate methadone for out-of- treatment adults with OUD. While there are no federal restrictions on in-hospital methadone use for OUD, until recently, federal rules required that patients present to an Opioid Treatment Program (OTP) to complete a methadone intake before receiving methadone treatment in the outpatient setting. Current usual care for hospital to OTP linkage includes a referral to an OTP at hospital discharge. At best, only 40% of patients referred to an OTP at hospital discharge link to an OTP. Patient-reported barriers to hospital-to-OTP linkage include opioid withdrawal, lack of transportation, uncontrolled medical and mental health conditions, and stigma. Recent federal regulations governing OTPs relaxed methadone intake rules now allow non-OTP affiliated clinicians to compete the medical evaluation required for a federally compliant OTP intake. In one study, 77% of patients who completed an in-hospital OTP intake linked to an OTP after hospital discharge. Federal regulatory changes and the expanding workforce of hospital-based addiction clinicians provide a unique opportunity to expand in-hospital OTP intakes. Using a novel staircase cluster randomized design with a hybrid type 2 approach, sites will be randomly assigned a time when the study team implements a series of core activities encompassed in “implementation facilitation” (IF). These core IF activities support uptake of clinical activities by hospital-based addiction clinicians and facilitate completion of a federally compliant in-hospital OTP intake. Guided by the Practical, Robust Implementation and Sustainability Model (PRISM), we will begin by identifying site-specific contextual factors important to the implementation of core IF activities including collection of quantitative and qualitative data to inform tailoring of IF activities to account for the local needs and resources at diverse study sites. Next, we will implement IF across study sites based on their randomly assigned start date to cross over from usual care to IF. We will test the effectiveness of IF on hospital-to-OTP linkage by comparing linkage rates during the usual care phase versus the post IF evaluation phase. Implementation outcomes are informed by PRISM's Reach, Effectiveness, Adoption, Implementation, Maintenance (RE-AIM) framework, and include measuring implementation fidelity to use of the core IF activities, adoption of the clinical activities required to complete an in-hospital OTP intake, measuring IF implementation costs, and measuring the proportion and characteristics of patients who did and did not link to the OTP. This study aims to measure the effectiveness of IF on hospital-to-OTP treatment linkage while also obtaining important implementation data for scaling to other treatment sites with an ultimate goal of expanding lifesaving OUD treatment to a vulnerable population.

NIH Research Projects · FY 2026 · 2026-04

PROJECT SUMMARY Type 1 diabetes (T1D) results from a misdirected immune response, and its incidence has been increasing globally for decades. Viral infection, particularly with enterovirus, is a leading candidate trigger for the initiation and progression of islet cell destruction that ultimately results in clinical disease. Evidence from cell, mice, and human studies support this hypothesis, however, the findings from natural history studies of children at-risk for T1D are inconsistent. We posit that genetic variability contributes to this heterogeneity. Infection susceptibility and resolution depend heavily on first-line immune defenses by natural killer (NK) cells and the complement system, both of which are increasingly implicated in T1D pathogenesis and bridge innate and adaptive immune responses. Genetic variability within the killer cell immunoglobulin-like receptor (KIR) and major histocompatibility complex (MHC) loci directly affects these immune functions. Our overall hypothesis, supported by our preliminary data, is that combinatorial genetic variation controlling NK cell and/or complement system activity determines the course by which viral infection may contribute to the initiation of persistent islet autoimmunity (IA) and/or progression from IA to T1D. The genetic effects of these loci in a possible viral etiology and pathogenesis of T1D have been understudied, likely because they reside in highly complex genomic regions that are measured at insufficient resolution using common technologies. We propose to overcome this measurement problem by performing targeted, high-resolution sequencing of the 5Mbp MHC and 250kbp KIR regions with our novel cost-effective, high-throughput methods for >2,900 at-risk children being followed prospectively for the development of IA and T1D in two independent cohorts: The Environmental Determinants of Diabetes in the Young (TEDDY) study and the Diabetes Autoimmunity Study in the Young (DAISY). We will integrate this new sequence data with existing array data to catalog structural, polymorphic, and functional immunogenetic variation using proven bioinformatic algorithms for measuring NK cell and extended complement system activation potential (Aim 1). This unprecedented, high-resolution immunogenetic catalog enables novel exploration of NK cell and complement system contributions to susceptibility and response to a viral infection (Aim 2), and to risk for developing IA or T1D (Aim 3). These hypotheses can uniquely be tested within TEDDY, which has unparalleled precise and frequent virus exposure assessment and offers large enough sample size to detect phase-specific associations between genetic variation, infectious episodes, and T1D endpoints. With our requested minimal, low-priority sample expenditure, we can deliver high-impact findings of the immunogenetics underlying the natural history of T1D. Elucidating the genetic factors that confer susceptibility to persistent viral infections leading to IA and/or T1D progression may identify mechanisms to target for therapeutic development and, critically, will inform the structure of ongoing vaccine and antiviral T1D prevention trials.

NIH Research Projects · FY 2026 · 2026-04

Project Summary/Abstract According to the organ procurement and transplantation network, every year more than 40,000 organs are transplanted in the United States; from those organs, over 4500 are related to heart transplantation. Two main limitations that exist with heart transplantation are #1: the waitlist continues to increase whereas the number of donor hearts has not changed. Unfortunately, over 60% of potential donor hearts are discarded. This leads to significant waitlist mortality and an unmet and growing need. #2: if fortunate to be transplanted, the recipient is subjected to lifelong immunosuppression leading to significant burden of infections, malignancies, and end-organ dysfunction while still experiencing a high risk of acute rejection (40% of recipients within the first year) and chronic rejection (over 50% of patients by year 5). This funding opportunity leverages a unique window of therapeutic opportunity by directly targeting the donor heart PRIOR to transplant when the heart is directly accessible. Using material science, nanotechnology and drug delivery, the investigators propose to engineer a novel delivery technology that can be applied ex vivo to the donor organ after procurement and prior to transplantation to improve organ transplantation. The proposed technology consists of a polymeric sheet that contains engineered nanoparticles (NPs). The NPs have a macrophage specific targeting peptide, a fluorescent marker for tracking, and a macrophage activation inhibitor in the core, to reduce pro-inflammatory signaling and recipient neutrophil and monocyte recruitment. Although heart transplantation will be investigated in this grant, this technology may be applicable to other organs to enable a broader use of previously discarded organs and to improve post-transplant outcomes. The goal of this R21 Trailblazer award is to develop an “off-the-shelf” therapy that can exist at every organ procurement organization (OPO) and that can be easily and reliably deployed to donor organs at the time of procurement. The invention will become part of the OPOs procurement pipeline. Importantly, we aim to create a workflow that will improve outcomes and allow increased utilization of “marginal” organs. This technology could be immediately translatable and can be modified to deliver therapies in a personalized medicine approach or can be applicable to other organs.

NIH Research Projects · FY 2026 · 2026-04

PROJECT SUMMARY Background: Rural older Americans are at heightened risk for developing and dying from critical illness. Yet despite having 22% of America’s older adults, rural communities only have 1% of America’s intensive care unit (ICU) beds. As such, rural ICUs are dependent on the network of hospitals around them to help care for their critically ill—making rural ICUs particularly vulnerable to external disruptions. Extreme weather events disrupt this network of ICU care and place older adults at risk of increased hospitalizations and mortality. Therefore, there is an urgent need to understand the long-term effects of extreme weather events on rural ICUs and the older adults they serve. Project Methods: Aim 1: The effect of extreme weather on one-year mortality among critically ill, rural older adults. Survival analyses will evaluate differences in one-year mortality after critical illness among older adults based on exposure to disaster and rurality using Medicare claims. Aim 2: Associations between rural hospital networks, interhospital transfers, and mortality among critically ill, rural older adults affected by disaster. Network analyses will characterize rural hospitals based on interhospital transfer networks. Then, relationships between rural hospital networks and 30-day mortality will be examined among critically ill, rural older adults affected by disaster. Aim 3: Healthcare readiness during disaster events when caring for critically ill, rural older adults. Semi-structured interviews with 45 staff members from four hospitals who cared for critically ill, rural older adults during disasters will create a framework that defines essential elements of healthcare readiness. Unique Aspects of this Proposal: This application tackles a pressing problem—the impact of extreme weather on vulnerable critically ill, older adults in rural communities—by uniting a physician-researcher with expertise in rural ICU care delivery with a nurse-researcher with expertise in the impact of disasters on the health and well-being of older adults. With an experienced team, expert National Advisory Board, and blend of quantitative and qualitative analyses, the PIs are uniquely equipped to address this urgent challenge. Anticipated Impact: Extreme weather events pose a major threat to critically ill older adults who receive healthcare in rural communities. This study will lead to interventions across individual, health system, and community levels that strengthen systems of ICU care and recovery and mitigate adverse health consequences for vulnerable, rural older adults.

NIH Research Projects · FY 2026 · 2026-04

PROJECT SUMMARY The unique interplay of physiological, psychosocial, and behavioral factors of adolescence that result in circadian misalignment and dramatically insufficient sleep may confer a notable risk towards cardiometabolic impairment in youth. Our work and others have demonstrated that circadian misalignment and insufficient sleep correlates with insulin resistance and glycemic variability in adolescents. With alarming rates of obesity and type 2 diabetes (T2D), today's adolescents are experiencing prolonged exposure to risk factors for early cardiovascular disease (CVD) and thus novel prevention/intervention approaches are needed. The combination of circadian misalignment and insufficient sleep may be one such important target. Our central hypothesis is that the negative cardiometabolic effects induced by delayed and short sleep during adolescence can be mitigated by improving sleep and circadian health. A potential mechanism may be the alterations in components of energy balance that occur with insufficient sleep and circadian misalignment. However, existing studies in the free-living environment using high quality methodology and focused on adolescents are lacking, a gap that this proposal aims to fill. Advancing circadian rhythms while also increasing sleep opportunity may optimally improve cardiometabolic risk and align the circadian clock to the timing of sleep and eating. We have successfully increased sleep duration in habitually short sleeping adolescents during a one-week sleep extension manipulation during the academic year; however, continued circadian misalignment was observed. Utilizing a randomized crossover trial design, the current proposal will compare the effects of a combined circadian and sleep manipulation vs typical sleep as a mechanistic probe to interrogate insulin sensitivity and energy balance among habitually short sleeping adolescents (≤7 h sleep/night on school nights) with overweight/obesity. Participants will be assessed following randomized completion in counterbalanced order of two weeks of typical sleep compared to two weeks of a circadian/sleep manipulation including chronobiotic tools and increased sleep opportunity. Low dose exogenous melatonin 2 hours before bedtime and morning bright light effectively advance circadian rhythms but use in combination with sleep extension and in adolescents is novel. We hypothesize that 1) insulin sensitivity will improve, while 2) energy expenditure and intake will decrease following the manipulation compared to typical sleep. The proposed work will result in an enhanced understanding of specific mechanisms underlying the relationship between sleep, circadian rhythms, and cardiometabolism in adolescents, with promise for future intervention and prevention efforts in a high-risk population.

NIH Research Projects · FY 2026 · 2026-04

ABSTRACT Cardiovascular diseases (CVD) are major chronic diseases and the leading cause of death in the United States and worldwide. Coronary artery disease (CAD), the most prevalent form of CVD, affects approximately 1 in 20 adults over 20 years old. Current treatments help manage risk factors but do not address thrombosis or restenosis comprehensively. Drug-eluting stents (DES) have improved restenosis rates but rely primarily on timed drug release, which fails to fully accommodate the multi-phase nature of vascular injury and repair. FDA approved DES effectively limit vascular smooth muscle cell (SMC) proliferation but also block endothelial growth required for vascular repair and has no effect on inflammation or chronic vascular remodeling resulting in incomplete healing, late stent thrombosis, and suboptimal long-term outcomes. PTEN is a key regulator of SMC function. Vascular SMCs are major contributors to pathological vascular remodeling through functional phenotypic modulation that plays a critical role in vascular disease progression. Our published and preliminary studies indicate that genetic and pharmacological upregulation/maintenance of PTEN levels actively preserves SMC phenotype, blocks inflammation, and prevents vascular disease progression in PTEN phosphatase- dependent and PTEN nuclear transcriptional-dependent manners. In contrast, SMC-specific depletion of PTEN exacerbates atherosclerotic lesion formation, injury-mediated restenosis, and hypertension-associated vascular remodeling making PTEN an essential and causal vascular protective target, which represents a novel concept for the treatment of cardiovascular disease. Unlike traditional DES, PTEN has been shown to directly target SMCs and block the major adverse events thereby mitigating neointimal hyperplasia, which is a major contributor to restenosis. Polymer poly-lactic-co-glycolic acid (PLGA) can be used as a promising delivery system due to their FDA approval, biodegradability, controlled drug release properties, cost-effectiveness, and commercial availability. These characteristics make PLGA polymers ideal for synthesizing PTEN encapsulated nanoparticles. For the current proposal, we hypothesize that engineered PTEN-PLGA nanoparticles will restore the contractile phenotype of SMCs, reducing proliferation, migration, and inflammation associated with restenosis. This approach has the potential to address critical gaps in current CAD treatment by offering a more precise and sustained intervention. As CVD cases continue to rise, developing a targeted therapeutic strategy is essential. A PTEN-PLGA nanoparticle system could transform restenosis prevention and provide a long-term solution to one of the biggest challenges in cardiovascular medicine. We propose that SMC targeted nanoparticle PTEN mRNA delivery will prevent SMC phenotypic modulation through PTEN-dependent maintenance of the contractile, differentiated VSMC phenotype and thereby inhibit in-stent restenosis. Two Aims are proposed to test engineered SMC-targeted PTEN-encapsulated PLGA nanoparticles in in vitro human SMC culture models and in vivo genetic mouse whole body delivery and rat stent-based delivery.

NIH Research Projects · FY 2026 · 2026-04

PROJECT SUMMARY Coxsackieviruses are single stranded RNA viruses in the enterovirus genus that cause a wide variety of disease symptoms in humans, especially in young children. The CDC reports that in the United States, there are approximately 10-15 million non-polio enterovirus infections each year, most of which are caused by coxsackieviruses. Despite this high case number, there are currently no specific treatments available for coxsackievirus infections. Coxsackievirus B3 (CVB3) is a common serovar that colonizes humans via the fecal- oral route and disseminates to other tissues such as the heart, pancreas, and central nervous system. In the pancreas, CVB3 infection can cause viral pancreatitis, a life-threatening inflammatory disease that often leads to complications like pancreatic cancer, organ failure, and type 1 diabetes. Furthermore, CVB3-induced pancreatitis is thought to precede CVB3-induced myocarditis, another lethal inflammatory disease caused by viral colonization of heart muscle tissue. While Coxsackievirus-induced myocarditis has received significant research attention, very little is still known about Coxsackievirus-induced pancreatitis. Recently, it was demonstrated that the cytoplasmic pattern recognition receptor NOD2, which induces innate immune signaling in response to infection and damage patterns in the cell, exacerbates pathogenesis and disease in CVB3 infected mice. This is surprising since NOD2 is host-protective during many viral and bacterial infections. Using a similar mouse model of CVB3 infection, we observed that inflammatory cytokine expression in the pancreas was significantly lower when NOD2 is not expressed in the intestinal epithelium, suggesting that intestinal NOD2 promotes inflammation in the pancreas during CVB3 infection. NOD2 is known to upregulate intestinal barrier function and upregulate mitophagy in response to the bacterial peptidoglycan fragment muramyl dipeptide (MDP). Additionally, mitophagy can downregulate inflammation due to a reduction in mitochondrial reactive oxygen species (ROS) production, which in turn downregulates NLRP3 inflammasome activation. If intestinal NOD2-mediated barrier function sufficiently inhibits translocation of bacteria to the pancreas during CVB3 infection, it may promote pancreatic NLRP3 inflammasome activation by limiting MDP/NOD2-mediated mitophagy. Since excessive host inflammatory response contributes significantly to disease severity during viral pancreatitis, the relationship between inflammasome activation and NOD2 autoregulation across the gut- pancreas axis may play an important role in disease outcome during CVB3 infection. These questions will be investigated with the following aims: Aim 1: Determine whether intestinal NOD2 barrier function inhibits host-protective activation of pancreatic NOD2 during CVB3-induced pancreatitis; and Aim 2: Determine if MDP-dependent activation of NOD2 in pancreas cells inhibits ROS-dependent inflammasome activation by upregulating mitophagy. These studies will elucidate the mechanisms of NOD2 signaling in both the intestinal epithelium and pancreas that promote inflammatory disease during viral pancreatitis.

NIH Research Projects · FY 2026 · 2026-04

ABSTRACT. Physical function refers to an individual's ability to perform daily tasks and activities and is a crucial aspect of overall health. Maintenance of physical function is the cornerstone of successful aging with declines in physical function associated with increased risk of hospitalization, institutionalization, and premature mortality. We and others have shown that chronic diseases, including HIV, can significantly accentuate the decline of physical function. The gut microbiome plays a pivotal role in the regulation of gut health. Alterations in gut microbial communities (dysbiosis) accompany physiological aging and emerging evidence illustrate links between the gut microbiome and physical function and frailty in older people without HIV. HIV-associated dysbiosis has been reported to be among the strongest disease-associated dysbioses, and associations between the gut microbiome and multiple aging outcomes in PWH have been observed. In a recent study of sedentary older people with and without HIV, we found that HIV serostatus modified the fecal microbiome, such that those with HIV had a unique microbiome with increasing age. Emphasizing the clinical relevance of these findings in a subsequent pilot study, we observed associations between gut bacterial abundance and physical function that differed between older people with and without HIV, highlighting the need to understand these relationships in different disease states. We recently explored associations between frailty and gut microbiome within the MACS/WIHS Combined Cohort Study (MWCCS), a large nationwide, ongoing observational cohort. Differences by age among both men and women with and without HIV were noted; importantly, specific genera were associated with lower or greater odds of frailty, a composite measure indicative of vulnerability with aging. Frailty is a broad syndrome and recognizing gut microbiome relationships to specific measures of physical function will provide greater specificity as to potential mechanisms. Moreover, understanding both bacteria abundance and functional output are needed to properly appreciate the complex relationship between gut bacteria imbalances and physical function. To investigate our central hypothesis that HIV- and age-induced gut dysbiosis is associated with physical function impairments, we will evaluate relationships between fecal bacteria abundance and functional potential with physical function using data collected as part of the MWCCS. We will first evaluate cross-sectional relationships (Aim 1) and then determine if gut microbiome patterns predict changes in physical function over time (Aim 2). The knowledge gained from this well-powered investigation into the gut- physical function axis will promote the development of effective population-specific, strategically designed and cost-effective adjunct microbiome-based therapies to prevent or reverse physical function impairments among older adults, including those with HIV who experience age-associated decline in physical function at an earlier age.

NIH Research Projects · FY 2026 · 2026-03

PROJECT SUMMARY Autism spectrum disorder (ASD) affects an estimated 1 in 36 children (2.8%) in the US and is among the top 10 causes of child disability worldwide. Despite its significant medical and economic burden, current therapeutics are limited and none of the available medications treat the 3 core symptoms of ASD: challenges with communication, social skills, and repetitive behaviors. Many of these therapies are based on research from a neuronal perspective – begging the question of whether other factors may be at play. Of the >800 genes associated with ASD, many are expressed in the cardiovascular system and people with ASD are at an increased risk of developing cardiovascular disease. Spanning >400 miles in the brain, the cerebral vasculature is crucial for proper brain function – facilitating rapid and localized increases in blood flow in response to elevated neuronal activity. This process, termed functional hyperemia (FH), is critical to supply neurons with sufficient oxygen and nutrients to function properly, as the brain does not have its own energy reserves. Our collaborators conducted a foundational study that established endothelial-dependent impaired FH in the 16p11.2 locus deletion (16pDel) mouse model of ASD which was published in Nature Neuroscience. Further, they have identified a compound that rescues endothelial function and behavioral phenotypes in this mouse model. Neuronal, vascular, and molecular mechanisms collectively termed ‘neurovascular coupling’ (NVC) underlie FH, yet these mechanisms have not been examined within the context of ASD. Our previous work has detailed a novel NVC mechanism whereby brain capillaries sense neuronal activity via Kir2.1 channels. Therefore, I aim to characterize Kir2.1 channel function and NVC in 16pDel mice. My preliminary data revealed general Kir2.1 channel dysfunction and impairment in Kir2.1-dependent NVC that is rescued with the compound specified above. However, additional insight to Kir2.1 channel dysfunction and the mechanism by which the compound acts to restore NVC is needed to develop viable therapies from this lens. Through my first aim, I will characterize the cell- and region- specificity of the Kir2.1 channel dysfunction – providing necessary insight to the function of the entire microvascular tree. The second aim will elucidate the mechanism by which this compound exerts its rescue effect. Specifically, I will determine if it enhances Kir2.1 channel function by increasing bioavailability of its crucial cofactor, PIP2. The findings hold promise to not only establish further evidence for the involvement of the cerebral vasculature in neurodevelopmental disorders, but also give mechanistic insight to a novel therapeutic avenue. This will provide foundation for an intriguing new field aimed at understanding the role of cerebral vasculature in cognitive function of young adults.

NIH Research Projects · FY 2026 · 2026-03

PROJECT SUMMARY The prevalence of inflammatory bowel disease (IBD) worldwide has been increasing dramatically in the past 30 years. Many individuals with IBD trial multiple medications before finding an effective treatment, and unfortunately many of these individuals develop resistance to treatments that were previously effective over their disease course. Genome wide association studies have identified mutations in interferon gamma (IFN𝛾) and its receptor which are associated with IBD pathogenesis. Moreover, patients with IBD produce high amounts of IFN𝛾 in their biopsies and sera. Current biologics available, such as Vedolizumab, and biologics in phase three clinical trials, such as Etrolizumab, target integrins which are important for intraepithelial lymphocyte (IEL) homing and retention in the colonic epithelium. Importantly, pathogenic CD103+ IEL subsets which secrete high levels of IFN𝛾 are enriched in patients with IBD. The colonic epithelium exists in a state a physiologic hypoxia at baseline, and during IBD hypoxia persists. Our lab has established that hypoxia inducible factor (HIF), a transcription factor that modulates expression of genes in hypoxia, is stabilized in the colonic epithelium at baseline and during disease. In fact, HIF stabilization is protective in mouse models of colitis, and is associated with decreased IFN𝛾 secretion. Our lab has demonstrated that in metabolically stressed T cells, HIF is stabilized and IFN𝛾 secretion is decreased. These data suggest that HIF stabilization represses IFN𝛾 secretion, and may be protective in colitis. Preliminary data I have generated suggests that HIF stabilization in the colonic epithelium attenuates IFN𝛾 response genes major histocompatibility complex II and class two transactivating protein. Importantly, IELs sit between epithelial cells and are primed to secrete IFN𝛾 in response to luminal antigens. Therefore, I hypothesize that HIF controls IEC responses to IEL-derived IFN𝛾 and modulates IEL recruitment and retention. This proposal will interrogate this hypothesis by 1) determining the function of epithelial HIF in epithelial MHC II dependent IFN𝛾 responses and 2) by elucidating the role of IEL HIF on IFN𝛾 secretion and CD103+ IEL retention in the colon. The physical location of IELs within the hypoxic intestinal epithelium underlies the importance of understanding the role of HIF stabilization in the interplay between IELs, their secreted cytokines, and the colonic epithelium. The goals of my fellowship training plan include: 1) developing technical skills and knowledge in the field of mucosal immunology as it relates to IBD, 2) becoming a highly skilled scientific communicator, and 3) building skills for my future career as a physician scientist in pediatric gastroenterology. Activities under this award will be completed at the University of Colorado Denver Anschutz Medical Campus. In summary, the project outlined in this proposal will address our gap in understanding the role of IFN𝛾 in colitis, as well as the role of HIF in modulating the intestinal epithelial-IEL axis, and prepare me for my career as a physician scientist.

NIH Research Projects · FY 2026 · 2026-03

PROJECT SUMMARY Older adults with Alzheimer’s disease and related dementias (ADRD) fall up to eight times more often than older adults with normal cognition, incur higher fall treatment costs, and 40% experience adverse outcomes after emergency department (ED) visits (e.g., ED revisits, hospitalizations). Although up to 40% of older ED patients have ADRD and falls are the #1 reason why persons living with dementia (PLWD) visit EDs, most ED- based fall studies exclude PLWD and none meaningfully include caregivers. The ED visit is a high yield, under engaged opportunity to address fall prevention. In GAPcare, the Geriatric Acute & Post-acute Care Coordination Program for Fall Prevention in the ED (R03 AG056349; K76 AG059983), fall prevention efforts are initiated in the ED immediately after a fall. Pharmacists identify patients’ fall risk increasing medication and suggest modifications using medication therapy management. Physical therapists (PTs) perform a brief assessment of fall risk and create plans to improve gait, balance, and mobility. Action plans co-created with patients and caregivers are electronically transmitted to outpatient clinicians at the end of the ED visit. The GAPcare randomized controlled trial (RCT) had high patient and caregiver satisfaction, did not prolong ED length of stay, and resulted in 66% fewer 6-month fall-related ED visits compared to usual ED care. Informed by patient and caregiver interviews (R61 AG069822 pilot) we adapted GAPcare for PLWD using Castro’s framework for prevention interventions. Seizing the momentum of our prior research and RCTs and harnessing the strengths of our team in ADRD clinical trials and Medicare analyses, we propose a multisite RCT to test the efficacy of GAPcareAD (intervention) versus usual care in 350 PLWD and their caregivers presenting to the ED for a fall. We will pursue the following three specific aims: (1) conduct a RCT (n=350) in three EDs of community-dwelling persons with ADRD to test the efficacy of GAPcareAD on patient and caregiver outcomes including a reduction in recurrent ED visits for falls at 6 months (primary), falls, serious injuries; improvement of caregiver burden, care transitions, and patients’ quality of life, (2) determine post-ED engagement with pharmacy and PT recommendation including whether medication changes were made, when, and by whom, and dose of outpatient PT, and (3) effect modification by participant (e.g. age, sex, race) and community characteristics (e.g., area deprivation index, social capital). GAPcareAD uses administrative data to pragmatically measure utilization and patient/caregiver centered outcomes. This study addresses a serious problem – high and increasing rates of ED visits for falls – and tests the efficacy of a brief, on-the-spot in-ED intervention in PLWD who have previously been excluded from interventional fall studies. GAPcareAD addresses three major priorities of the NIA: 1) dementia care, 2) improving ED-to-home care transitions, and 3) caregiver support. GAPcareAD’s pragmatic design prepares us for future widespread implementation in multiple EDs nationwide.

NIH Research Projects · FY 2026 · 2026-03

PROJECT SUMMARY/ABSTRACT. Excessive intake of sugar, and particularly fructose, has been linked to different metabolic health issues, including obesity, diabetes, and cardiovascular disease. Part of the reason for the strong association between high fructose consumption with metabolic diseases is because fructose -as sugar- is often added to processed foods to increase their palatability. One group that is particularly sensitive to the deleterious metabolic consequences of fructose is people with hereditary fructose intolerance (HFI). HFI is a genetic disease triggered by fructose that is caused by mutations in the aldob gene with serious health implications. As a result, individuals with HFI have defective fructose metabolism and accumulate this sugar as fructose-1-phosphate (F1P). This leads to severe reactions following fructose ingestion such as abdominal pain, symptomatic hypoglycemia, lactic acidosis, seizures and chronic metabolic consequences including growth retardation, chronic kidney disease and metabolic dysfunction-associated steatohepatitis. Further, if the exposure to fructose is continuous, HFI can be fatal. Unfortunately, there is no cure for HFI and therefore, any potential therapeutical approach needs to be explored. In this application, we continue the work from the previous award to investigate molecular mechanisms and metabolic pathways that we can target to treat this condition. We have identified that targeting ketohexokinase, KHK, the enzyme located upstream AldoB in the metabolic pathway of fructose, is a promising strategy to treat HFI as it will prevent the formation and accumulation of F1P. This finding has recently been confirmed in a proof- of-concept study in three individuals with HFI receiving a specific KHK inhibitor. However, further studies are necessary to assess individual safety with longer follow-up and clinically relevant endpoints. Here, we have developed a novel murine model of HFI, the aldobA149P mouse- which harbors an ortholog mutation of the most frequent variant in human HFI (the A149P). Initial characterization of aldobA149P mice demonstrate that this strain phenocopies the human disease and develop clear aversion to fructose. With this model, we propose to study two different yet complementary strategies to treat HFI. In the first aim of the application, we propose to conditionally repress KHK expression in selected cell types -enterocytes and hepatocytes- in adult aldobA149P mice and evaluate the subsequent behavioral and metabolic response to fructose. We will also evaluate if targeting KHK is a promising approach to reverse chronic HFI in mice. Second, we propose to perform CRISPR/Cas9-mediated in vivo gene editing to repair and correct the A149P missense mutation in the aldob gene of adult aldobA149P mice. Then, we will induce clonal selection and repopulation of the liver with repaired hepatocytes by exposing mice to fructose after which, fructose tolerability, the metabolic response to fructose and analysis of potential in vivo off-target effects will be evaluated.

NIH Research Projects · FY 2026 · 2026-03

PROJECT SUMMARY Homelessness is a public health crisis that often co-occurs with substance use disorders (SUDs) and HIV in the US. Despite this crisis, there exists a dearth of clinical researchers focused at improving health outcomes for people experiencing homelessness. To address this pressing need, we will establish a clinical research training program, Research Education for Addressing Challenges of Homelessness (REACH) Program, to foster the next generation of clinician investigators with the necessary interdisciplinary skills and experiences necessary to effectively design and conduct research related to SUD, chronic diseases, HIV, and homelessness. This will result in well-trained, multi-disciplinary researchers with expertise in SUD, HIV, and homelessness who can advance scientific evidence about how to provide optimal care for this population. The REACH program represents a unique collaboration between the University of Colorado School of Medicine, the Hennepin Healthcare Research Institute, and the National Health Care for the Homeless Council (NHCHC). The program will recruit four early career clinical research scientists at the post-doctoral and junior faculty (Assistant Professor) levels annually from the US through existing research networks, collaborations, and dissemination through relevant scientific meetings. The program involvement will last 24 months for each Scholar and will be comprised of specific course modules and seminars, biannual research workshops, and a mentored research experience which will be conducted at the participant's home institution. The program has the following aims: 1) To provide clinical research training in SUD and HIV within the context of homelessness to four REACH Scholars recruited annually for a 2-year fellowship; 2) To augment research and career mentoring of the REACH Scholars to support future NIH funding; and 3) To facilitate networking and sustainable research opportunities for REACH Scholars by leveraging community partnerships. The program is innovative in that it will leverage a unique, underused network, the NHCHC, the premier national organization working at the nexus of homelessness and health care that provides training and technical assistance to more than 200 health centers focused on improving the health of people experiencing homelessness. Along with an Institutional Mentor and Academic Advisor from the REACH Program, each Scholar will be paired with a Community Advisor who is someone with lived experience that can provide additional insight. Scientific guidance for the program will be provided by an Executive Committee and an External Advisory Committee. The network will include the institutions listed above as well as the University of California San Francisco, Oregon Health and Sciences University, the University of Alabama at Birmingham, and NYU Langone. The program will include a robust evaluation component that will include both individual and aggregate milestones that assess dissemination activities, grant submissions, and grants funded for two years following program participation.

NIH Research Projects · FY 2026 · 2026-03

PROJECT SUMMARY Down syndrome (DS) is caused by a complete or partial trisomy of chromosome 21 (Trisomy 21, T21). DS is characterized by widespread abnormalities in numerous tissue systems, leading to heart defects, vision problems, hearing loss, variable degrees of intellectual disability, and sleep apnea. In addition, those with DS are highly predisposed to hypothyroidism, blood disorders, and autoimmune conditions, and are known to undergo accelerated aging processes, leading to Alzheimer's disease (AD). The rapid pace of progress in DS research over the last decade highlights the critical need for effective communication between scientists, clinicians, families and self-advocates, to take basic research discoveries from the laboratory to clinical trials that benefit people with DS. Furthermore, continued advances in DS research are dependent upon the nurturing of the next generation of junior scientists. In this grant proposal we therefore request funding to cover travel expenses of junior investigators, postdoctoral fellows, and graduate students, to attend the 6th International Conference of the Trisomy 21 Research Society (T21RS), which will take place in Denver, Colorado, June 17-20, 2026. Attendees at this meeting will include established DS and non-DS investigators whose research directly or indirectly informs critical aspects of DS co-occurring conditions, including those mentioned above across the lifespan of individuals with DS. A new component the 2026 conference will be a workshop specifically for trainees during the first day, focused on novel technological advances in the field. The workshop will be open for all graduate and post-graduate students and will be include a mentor/mentee pairing session, allowing bridges to be built between different research groups, both within the USA and around the world. The mentees will self-select a junior or senior mentor from another research group and a panel discussion will be held including both mentors and mentees to discuss best mentor practices. Based on our previous successes, we anticipate that this conference will lead to fruitful discussions and novel collaborations that are essential for the future of DS research. The theme of our meeting will be: T21: Insights from Across the Lifespan.

NIH Research Projects · FY 2026 · 2026-03

Project Summary/Abstract: Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease. It affects over 2 million people worldwide but has historically been challenging to diagnose, categorize, and treat. MS has an autoimmune component that involves the production of B cell receptors (BCRs) and immunoglobulins (Igs) that inappropriately target the tissues in patients. We have recently reanalyzed all publicly available RNA sequencing data from MS patients and extracted over 5 million BCR immunoglobulin heavy chain (IGH) sequences. We then developed a language model capable of identifying BCR sequences associated with MS. In this project, we propose to test the effectiveness of this approach in distinguishing between MS patient peripheral BCR repertoires and those of patients with other neuroinflammatory diseases. We will select a subset of paired BCRs heavy and light chains with a high probability of association with MS and express them recombinantly as antibodies. We will determine if these antibodies bind neurons, myelin, glia, or other central nervous system (CNS) targets using a variety of methods. Based on our strong preliminary data, we expect that we will be able to accurately distinguish MS patients from other neuroinflammatory controls. We do not expect all recombinant antibodies we express will bind CNS targets, but the frequency of CNS target binding is anticipated to be significantly increased when compared to randomly selected control antibodies. This project is highly innovative and offers to make major advances in the field while being supported by strong preliminary data and an interdisciplinary team. Completion of this project may advance our ability to detect MS and other autoimmune diseases in blood samples and speed our ability to identify and study pathogenic antibodies in a variety of conditions.

NIH Research Projects · FY 2026 · 2026-03

PROJECT SUMMARY/ABSTRACT The rise of type 2 diabetes (T2D) in U.S. youth is an alarming public health issue. Although obesity is a strong risk factor for pediatric T2D, at the same time, only a subset of youth with obesity develops T2D, suggesting disease pathogenesis is driven by factors beyond total adiposity. It is well-established that altered body fat trafficking into abdominal and hepatic fats is strongly correlated with metabolic dysfunction in youth, independent of obesity. Recently, pancreatic traits assessed by imaging, particularly pancreatic fat and volume, have also emerged as potential risk factors for dysglycemia in youth. However, research examining the metabolic effects of these traits in youth has been limited to smaller cross-sectional studies, primarily conducted in clinical populations (i.e., children with existing obesity, fatty liver, or dysglycemia). Also, few, if any, human studies have explored the influence of the early nutritional environment on these pancreatic traits. In the proposed K99/R00 award, we will address these knowledge gaps by leveraging data from the Healthy Start Study, a longitudinal, pre-birth, cohort study in Colorado that has comprehensively characterized ~1,400 mother-child pairs since pregnancy. The applicant, Dr. Catherine Cohen, PhD, RDN, will add quantitative magnetic resonance imaging (MRI) sequences to scans performed at the next wave of visits when offspring are in adolescence (10-15 years) to measure pancreatic fat and volume. This data will then be used to pursue the following specific aims: Aim 1. Assess pancreatic fat and volume in a general risk cohort of adolescents and examine interindividual variation in relation to child characteristics and adiposity measures (K99). Aim 2. Test prospective associations of early nutrition/growth with pancreatic fat and volume in adolescence (K99/R00). Aim 3. Examine associations of pancreatic fat and volume trajectories across adolescence with trajectories of glucose-insulin markers across adolescence, and the role of pancreatic traits in mediating associations of early nutrition and growth with glycemic markers (R00).Taken together, the findings of this proposal will improve knowledge of the role of pancreatic traits as risk markers for early onset dysglycemia during puberty and generate insights that will enhance our ability to design and target T2D prevention strategies more effectively. The proposed training goals for the K99 phase will complement this research and focus on gaining: (1) experience applying lifecourse epidemiology concepts, (2) expertise in assessing body composition, especially adiposity measures, and (3) knowledge of pediatric T2D pathophysiology and dynamic glucose-insulin assessments, and will be achieved through individual mentorship, practical experiences, and didactic training, and supplemented with opportunities to expand professional development skills. Collectively, the proposed research and training activities will strategically equip the applicant with the knowledge/skills needed to transition from mentored (K99) phase to independent (R00) phase.

NIH Research Projects · FY 2026 · 2026-03

Project Summary: Primary focal segmental glomerulosclerosis (FSGS) is the most common primary glomerular disorder causing end stage kidney disease with the greatest incidence rates in African Americans. Unfortunately, few treatment options are available and are associated with significant morbidity. Acetylcholine represents a major neurotransmitter. However, evidence demonstrates acetylcholine is produced by non-neuronal cells. Notably, the non-neuronal cholinergic system regulates cell differentiation, cytoskeletal organization and protects against oxidative stress and apoptosis. We have discovered that the kidney can produce acetylcholine via a nonneuronal pathway. Using a transgenic mouse that expresses the sole enzyme that produces acetylcholine (choline acetyltransferase or ChAT), we have found ChAT is expressed in podocytes. We also identified that ChAT expression and acetylcholine production in podocytes can be increased by some drugs currently commercially available but are not being used to treat kidney disease. Importantly, ChAT and acetylcholine are increased in adriamycin-induced nephropathy, the prototypical experimental model of human primary FSGS, and preliminary studies suggest that its upregulation acts to attenuate kidney injury, reduce proteinuria, and preserve podocyte structure while reducing it has opposite effects. We also have evidence using cultured podocytes that acetylcholine plays a key role in preserving podocytes actin cytoskeleton. We hypothesize that the local synthesis of acetylcholine in podocytes is a mechanism for self-defense against injury in FSGS by protecting podocyte from damage and preserving podocyte structure. To test our hypothesis, we plan: (1) To identify the role of podocyte acetylcholine in protecting from kidney injury in FSGS. To accomplish this aim we will: (a) Test the hypothesis that lack of podocyte ChAT and absence of acetylcholine production will increase FSGS injury in mice and (b) we will determine if enhancing acetylcholine with FDA-approved drugs, can protect mice with FSGS from kidney damage. (2) To identify how acetylcholine protects the kidney from injury in FSGS. To accomplish this aim we will (a) Test the hypothesis that acetylcholine protects from kidney injury in FSGS by preventing podocyte oxidative stress and apoptosis and by preserving the normal structure of podocytes. In these studies, we will include experiments using human and mouse immortalized podocytes (b) To determine if the protective effect of acetylcholine in podocytes is mediated by muscarinic acetylcholine receptors. In these studies, we will use positive allosteric modulators for these receptors, and we will generate podocyte-specific muscarinic receptor deficient mice. The benefit of these studies is that we may have identified an unrecognized mechanism by which the podocyte can protect itself from injury and preserve its integrity. Importantly, we will also test approved drugs that can upregulate this host defense pathway. It is our hope that developing safe ways to harness endogenous mechanisms to block podocytes injury will reduce the need for nonspecific immunosuppressive therapies that can be associated with infections and toxicity.

NIH Research Projects · FY 2026 · 2026-02

PROJECT SUMMARY Despite existing immunosuppressive and anti-inflammatory treatments for IBD, the disease remains lifelong, and a burden for healthcare systems. Current treatments have variable efficacy, potential for sudden failure, and severe side effects. Novel immune targets are needed for developing universally effective therapies for managing active disease, regardless of genetic background. Additionally, relevant mouse models mimicking human IBD are essential to understand how these immune cells drive inflammation in patients. Mucosal-Associated Invariant T (MAIT) cells have gained significant attention due to their evolutionary conservation, abundance in humans, ability to recognize a range of microbes, and their roles in various diseases. They are highly enriched in mucosal and peripheral tissues, such as the gastrointestinal tract. MAIT cells express a T cell receptor (TCR) that recognizes microbial metabolites presented by MR1, a non-classical MHC molecule. At steady-state, MAIT cells express high levels of tissue homing molecules, and upon activation, MAIT cells produce inflammatory cytokines. These functional features of MAIT cells position them as key therapeutically relevant players in the modulation of inflammation at barrier tissues. However, in most standard laboratory strains of mice, the numbers of MAIT cells are extremely low, making in vivo studies challenging. The CC strain, CC011/Unc were previously shown to develop spontaneous non-lethal colitis with age. The establishment of this strain at our animal facility recapitulates features of chronic colitis including, colon thickening and ulceration, prominent lymphocytic and PMN infiltration of the mucosa and muscularis layer. Strikingly, we demonstrate that CC011 exhibits a high number of MAIT cells at steady state, moreover, the number of MAIT cells in the colon significantly increases during the development of colitis. Like human IBD, severe intestinal barrier disruption occurs, along with an influx of neutrophils, macrophages, TH17 cells, and inflammatory mediators such as IL-1α, IL-1β, and IFN-γ. Crucially, genetic deletion of the T cell receptor gene, Traj33 in CC011 resulted in almost obliterated MAIT cell development, and this coincides with a dramatic reduction in colon tissue injury and inflammation. We hypothesize that MAIT cells are intrinsically pathogenic and key to the development and maintenance of colitis. To test this hypothesis using single cell transcriptomics and leveraging our unique access to IBD patient samples, we will determine whether MAIT cells have pathogenic traits in human IBD (Aim 1). We will address the therapeutic potential of MAIT cells by modulating MAIT cells in vivo with potent MAIT TCR agonists and pro- inflammatory cytokines in the translationally relevant CC011 experimental model of spontaneous colitis (Aim 2). This proposal will provide new insights into the inflammatory networks that drive disease progression, pinpointing the mechanisms that drive MAIT cell pathogenicity during colitis and establish their role in instigating and maintaining disease. This work will also help determine the potential of MAIT cells as new therapeutic targets for treating active disease.

NIH Research Projects · FY 2026 · 2026-02

PROJECT SUMMARY The surface of the skin is persistently colonized with a community of bacteria that includes numerous different species and strains of coagulase negative staphylococci (CoNS). There is mounting evidence that these CoNS prevent colonization by pathogens such Staphylococcus aureus, and protect the skin from damage induced by this pathogen. Our central hypothesis is the innovative concept that human skin S. hominis make diverse bacteriocins to limit S. aureus-induced damage to the host. In support of this hypothesis, we have discovered that several skin S. hominis isolates make bacteriocins that kill S. aureus and limit skin damage in mouse models of infection. Our preliminary findings demonstrate that one of these bacteriocins is a novel daptide antibiotic (Shom_D1) that targets S. aureus membranes, and we have also identified resistance determinants for this new bacteriocin. To better understand these mechanisms and their significance to human skin protection, in Aim 1 we will identify additional S. hominis strains that produce protective bacteriocins. We discovered multiple new bacteriocins in preliminary screens, including Shom_D1 and a uniquely potent lantibiotic (Shom_L4). We will genome sequence and bioinformatically identify additional genetic loci encoding potential bacteriocins, and we will determine the breadth of skin commensal and pathogen killing activity of these identified bacteriocins. For selected molecules we will perform structure elucidation using mass spectrometry and NMR. In Aim 2, we will define S. hominis bacteriocin killing and resistance mechanisms. Since Shom_D1 is the first daptide antibiotic discovered in Staphylococci, we will focus on determining its mechanism of action and characterizing resistance determinants, and then extend into studies on Shom_L4. We will perform membrane permeability and lipid bilayer assays with purified bacteriocins vrs controls. Finally we will explore mechanisms of resistance and distribution of resistance determinants. In Aim 3, we will determine the ability of S. hominis bacteriocins to protect skin from S. aureus damage. Our preliminary studies indicate that Shom_D1 can protect the skin from S. aureus- induced inflammation and skin damage using a mouse epicutaneous model. We hypothesize that Shom_D1 and Shom_L4 will improve skin health through prevention of pathogen-induced inflammation and improve wound healing. We will test the purified Shom_D1 and Shom_L4, or we will use S. hominis bacteriocin producing strains, in competition with S. aureus in a mouse epicutaneous model and a wound model. We will also perform single cell and spatial RNA sequencing to determine host responses when S. aureus is challenged with Shom_D1 and Shom_L4 in a mouse wound model. Collectively, the findings from the proposed work will shed light on the mechanisms used by the commensal skin CoNS community to fight pathogens and protect the host.

NIH Research Projects · FY 2026 · 2026-02

PROJECT SUMMARY/ABSTRACT Cardiac IKr is a critical repolarizing potassium current shaping the human ventricular action potential. It is conducted by heteromeric assemblies of the human ether-à-go-go-related gene (hERG1) 1a and 1b subunits. These subunits are encoded by alternate transcripts of the hERG/KCNH2 gene and differ only in their amino- terminal regions. hERG1a/1b heteromerization is vital for normal CM function, as the imbalance of subunit expression and/or function results in cellular pro-arrhythmic behaviors. hERG1a/1b assembly is mediated by the co-translational association of the encoding mRNAs in HEK293 cells, cardiomyocytes derived from human induced pluripotent stem cells (hiPSC-CMs), and human myocardium. Evidence suggests that interaction between the nascent proteins is not required for the co-translational complex assembly. This grant's preliminary findings indicate that this complex assembly occurs post-transcriptionally and is promoted by direct interactions between hERG1a and 1b mRNAs governed by their secondary structures. In preliminary studies, RNA binding proteins DDX3X and DDX5 were identified as part of the complex, and purified DDX3X promoted hERG1a/1b mRNAs' association in vitro. In the K99 phase, I will define the mRNA structural features promoting the co-translational association and determine the affinity and energies of the RNA/RNA interaction using in vitro systems, isothermal calorimetry (ITC), mutagenesis, hybrid protein-RNA immunoprecipitation (RIP), and live-cell imaging. I will also determine whether DDX3X and DDX5 affect hERG1a and 1b mRNAs stability, translation, and association in hiPSC-CMs using qPCR, electrophysiology, Western Blot, ribosome profiling, RIP, and single molecule fluorescent in situ hybridization (smFISH). I will use quantitative ITC and in vitro reconstitution approaches to determine the specificity, affinity, and energies of the interaction between purified DDX3X and DDX5 with hERG1a and 1b mRNAs. I will also evaluate if DDX3X and DDX5 promote the association of the mRNAs in in vitro systems. In the R00 phase, I will determine whether the stability, translation, and association of hERG1a and 1b mRNAs are impaired in arrhythmias associated with type 2 long QT syndrome (LQT2). I will use hiPSC-CM disease models to evaluate half-life, translation rate, and association of the mRNAs with qPCR, ribosome profiling, RIP, and smFISH. These experiments will contribute to understanding ion channel biogenesis and elucidate molecular mechanisms underlying LQT2 related arrhythmias. This proposal is designed to fulfill my short-term goals of expanding my skills in cardiovascular research and biophysics and transitioning into the independent phase of my career. This will ultimately allow me to obtain my long-term purpose of linking RNA and ion channel biophysics to translational cardiovascular research.

NIH Research Projects · FY 2026 · 2026-02

Project Summary/Abstract Sepsis, the body’s injurious response to infection, afflicts nearly 50 million people worldwide annually with a particularly high burden in older patients. The majority of sepsis survivors experience prolonged or permanent brain dysfunction. We have recently discovered that this form of post-septic impairment is partially driven by a pathologic organ crosstalk between the systemic vasculature and brain, a process that may be exacerbated by age. The endothelial glycocalyx, a heparan sulfate (HS)-rich layer that lines the lumen of all blood vessels, is degraded during sepsis, releasing highly biologically active HS fragments into circulation. These circulating HS fragments selectively deposit within the hippocampus and can worsen cognitive outcomes in sepsis survivors. Strikingly, circulating HS levels are 5-fold higher in older (≥65) compared to younger patients (<50) with sepsis. This aging-associated increase in HS shedding may be due to a more fragile endothelial glycocalyx. In preliminary preclinical studies, we have found that increased age was associated with ultrastructural changes of the glycocalyx, including a loss of 6-O sulfation residues within endothelial-derived HS. Loss of 6-O sulfation is known to increase HS susceptibility to degradation by heparanase, the “sheddase” responsible for glycocalyx degradation during sepsis. This loss of sulfation may be due to increased circulating Sulfatase-2 (Sulf2) an enzyme dedicated to removal of 6-O sulfates from HS as 1) preliminary single cell RNA sequencing of peripheral blood mononuclear cells demonstrated that aged humans have increased levels of Sulf2 in monocytes and 2) aged mice exhibited increased blood Sulf2 activity. Based on these preliminary observations, we hypothesize that age-related remodeling of endothelial HS by monocyte-derived Sulf2 predisposes older patients to release brain-penetrating HS during sepsis, which will be associated with post-septic brain dysfunction. We will rigorously test this hypothesis in both pre-clinical models of sepsis and a prospective, observational cohort of patients with sepsis. We will specifically 1) determine whether age-related increases in expression of Sulf2 in monocytes are responsible for endothelial glycocalyx fragility in older mice; 2) determine whether age-related increases in expression of Sulf2 in monocytes exacerbate pathogenic HS deposition during sepsis in aged mice; and 3) identify whether circulating pathogenic HS fragments are associated with impairment in multiple cognitive domains in older sepsis survivors. This work will mechanistically investigate a unique form of age-related pathologic interorgan communication: release of brain-penetrating, pathogenic HS from the systemic vasculature. Critically, it may also identify Sulf2 inhibition as a therapeutic target in sepsis, which could improve the lives of millions of older survivors per year.

NIH Research Projects · FY 2026 · 2026-02

Project Summary This proposal addresses the protective function of the airway microbiome against infection with the major bacterial pathogen Staphylococcus aureus. In the upper airway, the abundance of non-pathogenic Corynebacterium correlates with reduced colonization and infection with S. aureus and other pathogens. Further, longitudinal studies indicate that Corynebacterium abundance is predictive of infection risk, with a greater abundance of Corynebacterium associated with reduced risk of infection. However, the mechanisms by which Corynebacterium may contribute to infection defense remain largely unclear. In recent work published in Infection and Immunity, we found that pre-exposure to Corynebacterium results in improved clearance of S. aureus from the lungs in a mouse infection model. This enhanced protection correlated with reduced S. aureus adherence to human respiratory tract epithelial cells in vitro. We also discovered that Corynebacterium cell-free conditioned media (CFCM) was sufficient to block the activity of S. aureus hemolysins, a key virulence feature of this pathogen. Preliminary data suggest a secreted protease in Corynebacterium CFCM is responsible for hemolysin inhibition. Using size exclusion chromatography, we identified a specific fraction of the CFCM containing the hemolysin blocking activity. For this proposal, we aim to identify and characterize the putative Corynebacterium protease responsible for blocking S. aureus hemolysis. Hemolysins are a type of pore forming toxin in S. aureus which can lyse several host cell types including red blood cells, epithelial cells, and neutrophils, a critical innate immune cell that contributes to S. aureus clearance by bacterial killing. Our overall hypothesis is that a Corynebacterium secreted protease improves protection against S. aureus infection by cleaving pore forming toxins, resulting in reduced S. aureus cytotoxicity in epithelial cells and neutrophils. To address this hypothesis, Aim 1 will focus on the identification and characterization of the Corynebacterium protease. Our preliminary data indicate that Corynebacterium CFCM blocks hemolysis of red blood cells caused by alpha-hemolysin (Hla). The known properties of Hla hemolysis will be used to interrogate the steps which are impaired by Corynebacterium activity, including binding to the receptor ADAM10 and pore formation. Aim 2 interrogates the effect of Corynebacterium CFCM on epithelial cells and neutrophils as two key host cells mediating defense against S. aureus infection. Together, these studies will advance our understanding of how Corynebacterium contribute to protection against S. aureus by abrogating S. aureus pore forming toxin activity and characterize a novel factor responsible for Corynebacterium-mediated interference with S. aureus virulence activities.

NIH Research Projects · FY 2026 · 2026-02

PROJECT SUMMARY/ABSTRACT Diabetic neuropathy (DN) is a painful and debilitating condition that affects 50% of people with diabetes. Despite its high prevalence, the precise biological mechanisms of DN are not known and no disease arresting treatment is currently available. An important barrier to effective natural history studies and interventional clinical trials in DN has been the paucity of non-invasive, clinically meaningful biomarkers. Blood concentrations of neurofilament light chain (NFL) have proved useful in select acquired and genetic nerve disorders, however, these have important limitations as biomarkers for DN. Our recent study examining plasma NFL concentrations in youth-onset type 2 diabetes demonstrated that NFL is elevated in people with diabetes both with and without neuropathy, likely owing to its release in response to axonal injury in both the central and the peripheral nervous system (PNS). The overall goal of the proposed studies is to define specific membrane-bound extracellular vesicle (EVs)-derived protein biomarkers of PNS origin for diabetic neuropathy (DN). The analysis of proteomic profiles in EVs has recently emerged as a strategy to identify tissue specific biomarkers in several central nervous system disorders, including Down syndrome, Alzheimer's disease, Parkinson's disease, and traumatic brain injury. EVs are secreted by all cell types, however, they can be traced back to their cell of origin using their specific surface markers. We new technique derived propose to employ a broad proteomic approach to identify EV-derived biomarkers relevant to DN. Subsequently, we will translate our specific-cell type EV enrichment to evaluate whether inflammatory and neurotrophic markers can be detected in Schwann cell (SC)- EV cargo.Our overall hypothesis is that the use of these two unique technical approaches will allow for the identification of unique EV-derived protein signatures for DN. To address this hypothesis, we have developed two specific aims. In Aim 1, we will use the new Mag-Net technology to carry out a high- throughput proteomic analysis to define new EV-derived protein markers specific to DN. In Aim 2, we will interrogate the PNS using a targeted approach to examine the cargo of SC-derived EVs. We will use immunocapture techniques to target surface markers specific to SCs and examine the cargo of SC-derived EVs for inflammatory and neurotrophic markers in participants with DN, as compared to controls and two forms of genetic neuropathy. Our interdisciplinary team includes world renowned experts in diabetes, EV methodology, proteomic approaches, and neuropathy biomarker development, and is therefore in a unique position to successfully execute this work. The biomarkers use of combined argeted and untargeted approaches will maximize our ability to define new EV-derived for DN and lay the groundwork for more detailed, prospective studies. t