University Of California, San Diego

NIH Research Projects · FY 2026 · 2022-04

PROJECT SUMMARY This is a submission of a K23 application by Dr. Rakesh Malhotra, MD, MPH, a nephrologist at University of California San Diego (UCSD). Through this proposal Dr. Malhotra intends to establish himself as an independent investigator studying non-invasive microvascular measurements in chronic kidney disease (CKD). Candidate: Dr. Malhotra’s training objectives include; 1) to become proficient in the measurement of non- invasive microvascular techniques and translation to patient-oriented research; 2) to gain expertise in advanced statistical methods relevant to clinical trials; and 3) to learn the necessary skills to develop an independent research program and to design and lead clinical trials. Dr. Malhotra will accomplish these objectives through mentorship, coursework, and participation in workshops. He has assembled a multidisciplinary team of scientists including Dr. Joachim Ix, an expert clinical trialist (primary mentor), Dr. Boy Houben, a leader in the field of microcirculation (co-mentor); Dr. Matthew Allison, a leader in the field of vascular health and assessment (co-mentor) and Dr. Florin Vaida, a PhD level biostatistician (statistical co- mentor). In addition, Dr. Haiyan Zhang a renal pathologist with experience in nephropathology and Dr. Ithaar Derweesh a urologist with expertise in minimally invasive surgery will participate as a consultant without pay. Research: Renal microcirculation plays an important role in the pathogenesis of CKD. The kidney biopsy is the standard technique to assess abnormalities in renal microvasculature, but is invasive and rarely done. Dr. Malhotra’s overall hypothesis is that the non-invasive microvascular measurements may improve our understanding of the renal microcirculation, and improve our ability to identify those at risk of kidney disease progression. In Aim 1, Dr. Malhotra will evaluate the relationship between non-invasive microvascular measurements (skin capillary density and % recruitment (by capillaroscopy) and heat-induced skin %- hyperemia (by laser Doppler)) with glomerular sclerosis among 100 individuals with CKD undergoing kidney biopsy and 50 persons with CKD undergoing nephrectomy for suspected kidney cancer. In Aim 2a, Dr. Malhotra will evaluate the association of clinical risk factors with microvascular dysfunction as assessed with capillaroscopy and laser Doppler among 200 CKD subjects. In Aim 2b, Dr. Malhotra will determine the associations between skin microvascular function and longitudinal changes in kidney function in the 200 CKD subjects. Lastly, in Aim 3, Dr. Malhotra will evaluate whether acute changes in % capillary recruitment in response to a dietary protein load is correlated with concurrent changes in eGFR, as measure of RFR in 20 CKD subjects. Both the training and research plans will lay the groundwork for use of non-invasive microvascular techniques in clinical trials to allow assessment of renal hemodynamics and monitor responses to therapies and clinical outcomes in the next and independent phase of Dr. Malhotra’s career.

NIH Research Projects · FY 2026 · 2022-04

PROJECT SUMMARY / ABSTRACT Oxidative stress is a central part of innate immune-induced neurodegeneration in neurological disorders including multiple sclerosis (MS). However, the molecular mechanisms regulating oxidative stress gene circuits to promote neurotoxic immune responses remain poorly characterized. Emerging evidence supports a role for the epigenome in tightly regulating immune cell gene activity in MS. Yet, the epigenomic landscape and function in prooxidant, neurotoxic central nervous system (CNS) innate immune cells in MS remains unknown. Thus, discovery of drugs capable of selectively suppressing immune-driven neurodegeneration has been hindered by lack of molecular understanding of neurotoxic functions of CNS innate immune cells. The ultimate goal of this project is to define the regulatory landscape of prooxidant immune cells and identify mechanisms that translate epigenetic aberrations into innate-immune driven neurodegeneration for devising novel therapeutic interventions for MS. Our preliminary data discovered a molecular convergence of neurotoxic microglia and peripheral macrophages to a core oxidative stress gene signature in MS model. By applying an innovative experimental design with cutting-edge methods, this proposal aims to define the epigenetic and transcriptional components of oxidative stress-producing innate immune cells in a mouse model of neuroinflammation for MS through unbiased profiling of the open chromatin landscapes (Aim 1) and histone modifications (Aim 2). These molecular characterizations will identify key MS-related regulatory elements that will be functionally validated in vitro and in vivo with CRISPR interference assays (Aim 3). This project will provide a foundational epigenomic outlook on the molecular circuits governing prooxidant, neurotoxic immune responses in neuroinflammatory disease, and the research outcomes may reveal candidates for the development of new treatments for innate immune- mediated oxidative injury in MS and related conditions. The comprehensive training plan will enable the PI to achieve his career goal of launching a successful independent research laboratory dedicated to studying epigenomic mechanisms contributing to immune dysfunction in MS for targeted treatments. The MOSAIC UE5 mentoring, leadership, and diversity training will facilitate his transition to independence and enable the PI to enhance diversity in the biomedical workforce in the R00 phase and beyond. As a mentee in Dr. Katerina Akassoglou’s laboratory, a leader in neurovascular and immune mechanisms of MS pathogenesis, at the esteemed academic environment of Gladstone Institutes and University of California, San Francisco, the PI will obtain new training in functional epigenomics and CRISPR genome engineering during the K99 phase. The PI’s training and career development will be bolstered through an advisory committee of faculty with related expertise; and the PI’s participation in didactic activities such as coursework in epigenomics and seminars, will collectively allow the PI to complete this project and integrate these approaches for making meritorious contributions to the fields of MS and epigenomics in future independent research.

NIH Research Projects · FY 2026 · 2022-04

Abstract The central goal of this proposal is to understand the neural systems subserving the decision to use the left or right hand1 – a simple choice that is central to our daily functions. Here we focus on parietal mechanisms of limb selection. Despite it being one of the most common decisions faced in everyday behavior, a largely neglected aspect of decision making is deciding which hand to use to achieve a goal. For instance, when deciding which hand to use to flip a light switch upon entering a room, the choice is influenced by many factors. These factors include what each hand is already doing (e.g, holding a phone), proximity of each hand to the switch, and future goals (e.g., desire to subsequently pick up an object with a particular hand). Our long- term goals are to elucidate the fundamental mechanisms of limb selection and movement coordination. Because limb selection is present in most behaviors, this work will provide insights broadly applicable to motor control. The posterior parietal cortex (PPC) is known to be involved in the planning and control of actions in an effector-specific manner. An emerging concept is that the same PPC regions that are involved in movement preparation and control also participate in action selection. We recently demonstrated that a parietal region known to contribute to the planning of arm movements and dubbed “the parietal reach region” (PRR), codes the spatial targets for reaches with the contralateral arm but receives information about the ipsilateral arm from the opposite hemisphere. PRR has also been implicated in the decision to reach versus saccade to a spatial target. In our first aim, we characterize limb selection behavior and determine the factors that drive limb selection. In our second aim we test the hypothesis that PRR is involved in limb selection during unimanual reaching. Next, we examine interhemispheric communication as a function of limb choice. Finally, we use reversible inactivation of the callosal fibers connecting PRR in each hemisphere to determine the role of interhemispheric competition in determining which limb to use. Collectively, these studies will have a broad impact on the field by illuminating the roles of PPC and callosal connections in a fundamental choice motor behavior. The results will lay the foundation for future studies that probe the larger bilateral frontoparietal network involved in movement control. The work may inform rehabilitation approaches for patients with neurological disorders including stroke and traumatic brain injuries in whom limb use is affected. 1 We will use the terms limb, arm, and hand interchangeably.

NIH Research Projects · FY 2026 · 2022-04

We propose a series of studies that apply a cognitive neuropsychological approach to investigate the behavioral presentation of Alzheimer’s disease (AD) in Spanish-English bilinguals. We use models of bilingual language processing and cognitive decline in AD to motivate experimental manipulations that will reveal the mechanism/s underlying cognitive deficits in bilinguals with AD. We also address critical practical questions, aiming to determine if bilinguals should be allowed to use either language during cognitive assessment, if testing in one language hinders subsequent performance in the other, and more generally how to maximize test performance and test sensitivity to AD in bilinguals. Theoretical considerations begin with evidence that although bilinguals do not seem different from monolinguals when they speak in just one language, both languages always remain active (they cannot just “shut one language off”). Bilinguals also switch languages both across contexts (e.g., at home vs. at work), and within sentences (when conversing with other bilinguals). By virtue of using each language only some of the time, bilinguals also use each language less frequently than monolinguals who only use the one language they know. Thus, bilinguals face unique control requirements in their everyday language use: choosing which language to speak, switching languages, retrieving less frequently used linguistic representations, and managing competition between languages. Together, the proposed studies will examine how these differences affect some of the most commonly used cognitive tests (e.g., picture naming, list memory, verbal fluency). These studies will also examine experimental tasks designed to elicit more naturalistic connected speech, including a referential communication task and a read- aloud task that recently demonstrated sensitivity to AD in bilinguals. Each proposed study focuses on key factors that we hypothesize can affect test performance – especially in bilinguals with AD, including: (a) switching languages across testing blocks (order effects), (b) switching within a testing block (the “either language” option), and (c) switching with varying degrees of support from semantic and syntactic context. We hypothesize that relative to healthy controls, bilinguals with AD will exhibit larger testing order effects, and reduced benefit from the option to “use either language” (which invites voluntary language switching). Bilinguals with AD may also exhibit more prominent switching deficits and reduced ability to exert control over the dominant language when language switches are not supported by syntactic context. The proposed studies will develop unique tools for diagnosis of AD in bilinguals and will reveal which cognitive mechanisms are critical for managing activation, representation, and use of two languages in a single cognitive system. In turn, the proposed studies will constrain psycholinguistic models of bilingual language processing and will provide clues as to how bilingualism leads to higher maintenance of cognitive functioning in older age by revealing which aspects of bilingualism are most challenging in AD.

NIH Research Projects · FY 2026 · 2022-04

ABSTRACT: Dr. Jerban is postdoctoral researcher with a multidisciplinary background who is proposing a research entitled “Knee evaluation under mechanical loading by Cones Ultrashort Echo Time MR imaging” through NIH K01 program under the mentorship of Drs. Christine Chung, Samuel Ward, and Jiang Du to develop into an independent investigator. Improving the osteoarthritis (OA) diagnosis at early stage using Magnetic Resonance Imaging (MRI) techniques are limited by three main barriers. First, the current clinical MRI techniques do not acquire signal from short T2 tissues, such as the meniscus and the deep layer of cartilage. Second, most Ultrashort Echo Time (UTE) MRI techniques that can acquire signal from short T2 tissues are orientation sensitive. Third, knee MRI is routinely performed on joints at rest, which incompletely mimics the actual physiological condition, particularly, the loading aspects. Recently, we have developed new UTE-MRI techniques (UTE-Ad-T1ρ and UTE-MT) that are not orientation-sensitive and that are designed specifically for scanning short T2 tissues of the knee. We have hypothesized that scanning knee joints during mechanical load application using these orientation-insensitive techniques will reveal the mechanical properties of the joint tissues, which in turn will help to distinguish between healthy, early stage and mild OA knee joints. We also hypothesized bone remodels in order to enhance the support to cartilage/menisci regions with defected cartilage, which complementarily confirms the early stage OA diagnosis. A research study is proposed to cover three main specific aims: dissected specimens’ study, whole knee cadaveric study, and in vivo study. First, we will accelerate the UTE-MRI techniques and then will investigate their variation patterns in healthy and moderate OA human cartilage/menisci specimens during the loading/unloading process. We will also assess the supporting bone specimens to compare with UTE variation patterns in cartilages/menisci under loading. Second, we will build and verify a pneumatic loading setup for the cadaver whole knee study, which is meant to assess the temporal variation of knees under a set of loading and unloading steps. Then the UTE-MRI variation patterns in joints from healthy, mild OA, and moderate OA groups during the loading/unloading process will be investigated. Third, we will design and build a separate loading device to perform the in vivo phase of the study. We will determine if in vivo UTE-MRI variation pattern under loading are distinct for early stage OA patients, and if UTE-MRI/CT can detect an improved bone structure and properties for early stage and mild OA knees. The feasibility of accelerating our orientation-insensitive UTE-MRI techniques and the significant sensitivity of our techniques to changes in knee tissues during mechanical load application (using an initial design of loading device) have been demonstrated in our preliminary results. Dr. Jerban and his mentors, Drs. Chung, Ward, and Du, have designed a detailed training plan and assembled a strong team of advisors to guide Dr. Jerban through his career development plan towards becoming an independent investigator.

NIH Research Projects · FY 2026 · 2022-04

Project Summary/Abstract Background: Cancer originates from genetic alterations that lead to changes in gene expression programs that promote tumor survival, growth, motility and inhibits differentiation and apoptosis. The mRNAs from this oncogenic gene expression program must be exported to the cytoplasm to be translated into protein in order to promote tumorigenesis. Whether there is regulation of export of tumor specific mRNAs and the potential proteins involved in this process is unknown. We have shown that tumor specific NXF1 adaptor proteins regulate export of oncogenic mRNAs. The adaptor proteins are also highly upregulated during tumor initiation and knockdown of specific adaptors inhibit tumorigenesis. Objective/hypothesis: This proposal seeks to understand the molecular mechanisms driving the progression from normal to neoplastic skin using a RAS driven human epidermal tumor model. Our preliminary data suggests that 4 adaptor proteins are highly upregulated during tumor initiation that associates with NXF1 to mediate the export of the oncogenic gene expression program. Our objective is to characterize the role of each tumor induced NXF1 adaptor protein in the progression of normal to neoplastic skin. Furthermore we seek to determine the specific transcripts that each adaptor protein binds during tumor initiation to promote tumorigenesis. Specific Aims: (1) To determine the role of NXF1 adaptor proteins in the progression from normal to neoplastic skin and (2) to identify the transcripts associated with NXF1 adaptor proteins and determine which bound transcripts are exported. Study Design: To study epidermal tumorigenesis in a more clinically relevant setting, we generate 3-dimensionally intact human skin, containing human epidermal cells (that have been permanently knocked down for adaptor proteins) in the context of human dermal stroma and basement membrane, regenerated on immune compromised mice. By using this model, we can perform loss of function experiments on NXF1 adaptor proteins in regenerated human skin to characterize their role in epidermal growth, differentiation, and progression to neoplasia. We will use CLIP-Seq to determine the RNAs associated with each adaptor protein during the progression from normal to neoplastic epidermis.

NIH Research Projects · FY 2026 · 2022-04

OVERALL: Leaving, Coming, and Staying HIV Obligate Microenvironments (HOME) ABSTRACT Viral, host and environmental mechanisms governing HIV reservoir dynamics on and off antiretroviral therapy (ART) must be grasped more deeply if cure efforts are to be successful. Further, variability in the size, distribution and activity of the reservoir is substantial, and although a ‘one size fit all’ HIV cure strategy is seducing, a reductionist ‘bulk’ approach cannot fully capture the complex underlying processes of HIV reservoir dynamics. To better define the viral, host and environmental factors that govern these dynamics at the cellular and single- genome level, our novel Leaving, Coming and Staying HIV Obligate MicroEnvironments (HOME) program builds on our previous infrastructure, and success, including our ‘Last Gift’ cohort, which enrolls altruistic people with HIV (PWH) who did or did not stop ART before death, collects pre-mortem clinical data and limited samples, then performs a full body rapid autopsy with sample collection across the body within 6 hours of death. The rationale for our program is that the use of new single-cell and single-genome technologies will bring new perspectives on assumptions built on bulk technologies and help identify vulnerabilities in HIV reservoir states: • Leaves HOME when HIV (re)activates from tissues during ART (i.e., ‘ready to move once ART is interrupted’, like packing its bag and getting ready to leave) and causes rebound viremia during ART interruption. • Comes HOME when HIV (re)populates tissues during viremia off ART and through the spread of clonally expanded HIV-infected cells while on ART. (Clonal expansion is like adding family to the home.) • Stays HOME when HIV persists in tissue reservoirs during ART and viral suppression in plasma. The HOME program is organized into three Research Projects (RP) to investigate these reservoir dynamics: • The Viral, EpigeNetics and Integration (VENI) RP will investigate viral and proviral epigenetic factors. • The Viral, Immunology, Drugs, and Imaging (VIDI) RP will investigate host and environmental factors. • The Viral, Immune, and Cellular data Integration (VICI) RP will develop new methods needed for the integration and analysis of complex multi-dimensional data. These three RPs will be supported by two cores: the Administrative and Data (AD) Core will provide leadership, communication and data services, and the Clinical, Outreach, Pathology and Ethics (COPE) Core will direct and ethically oversee the Last Gift cohort. Our proposed HOME program is a good use of resources because it innovatively responds directly to the Understanding HIV Reservoir Dynamics RFA (AI-21-013) and will create the next level of understanding of deep HIV reservoirs. We expect to clearly define the viral, immunological, cellular expression, epigenetic, tissue architectural factors associated with specified HIV reservoir states across the human body on and off ART. Such results would be foundational for HIV cure strategies aimed at locking down or clearing HIV reservoirs.

NIH Research Projects · FY 2025 · 2022-04

This proposal intends to generate novel, widely available reagents and methods to Improve the measurement of Lp(a) levels in order to improve patient care. Elevated Lp(a) levels are highly prevalent and generally accepted as an independent, genetic and likely causal risk factor for CVD. Although Lp(a) levels are measured in clinical laboratories, it is one of the most difficult laboratory analytes to measure accurately because of its unique structure of multiple, identical kringle repeats. Significant technological and methodological gaps exist that limit the accuracy of Lp(a) measurements at the both the clinical laboratory and clinical level. The major limitation is the lack of widely available, globally standardized, diagnostic methods, and specifically monoclonal antibodies that bind only once to Lp(a) that can be used to accurately quantitate Lp(a). This lack of standardization may have adverse clinical sequalae by mis-assigning Lp(a) risk thresholds or targets for therapy. Due to the limitations noted above, the FDA has yet to approve any Lp(a) assay in molar concentration. The NHLBI Working Group on Lp(a) organized 2 workshops in 2017 and 2019 and recommended constructive collaboration among all stakeholders to ensure standardization and harmonization of Lp(a) assays and to develop assays that are isoform independent using monoclonal antibodies that are specific to one site on apo(a). To address these gaps in the care of patients with elevated Lp(a), we propose the following specific aims: 1- to develop and validate an isoform independent Lp(a) assay with a recently generated isoform-independent, monoclonal antibody; 2- to generate a second, isoform- independent, monoclonal antibody to facilitate the development of a first, isoform-independent non-ELISA methodology adaptable to hospitals and commercial laboratories. We will collaborate with the CDC/IFCC to validate this new ELISA at the clinical laboratory interface; and 3- to apply these novel assays to clinical datasets for translatability to human disease, including studies of racial/ethnic differences, antisense Lp(a)- lowering therapy and in CVD outcome studies.

NIH Research Projects · FY 2026 · 2022-04

Project Summary/Abstract This project will directly advance the NIDA strategic objectives to “enhance knowledge of the real- world landscape of drug use.” The training activities of this project will include: 1. Acquire foundational knowledge of the way that cannabis products have been explored as a medicinal product and how they are regulated. (TG1); 2. Develop the fundamental skills and knowledge required to apply natural language processing (NLP) approaches of text analysis. (TG 2); and 3. Further develop the general skills needed to be an independent substance use researcher, including ethical conduct of research for substance using populations, grantsmanship, manuscript writing, policy briefing and presentation to legislators, and cross-disciplinary research (TG3). The research of this K01 is to characterize epidemiology of CBD use among US adults (18+ years). A single survey (target n=1500) will be used complete the following specific research aims: 1. Describe the characteristics of CBD users (Aim 1), 2. Characterize CBD use as a substitute or adjunct to other medications. (Aim 2), and 3. Characterize self-reported CBD-related adverse events (Aim 3). All aspects of this research and its future applications will be enhanced by the growth in my understanding of cannabis regulation (TG 1) and NLP (TG 2). Dissemination activities for the projects include peer-review publications, conference and symposium presentations, and developing policy briefings and presentations to state legislature.

NIH Research Projects · FY 2026 · 2022-04

Abstract Intervertebral disc (IVD) degeneration and related low back pain (LBP) affect up to 85% of the U.S. population over their lifetime, resulting in annual healthcare costs that exceed $100 billion. The IVD is largely avascular and consists of a central proteoglycan (PG)-rich nucleus pulposus (NP), and a surrounding collagen- rich annulus fibrosus (AF), as well as superiorly and inferiorly located endplates. The IVD relies on diffusion of nutrients and waste through the cartilaginous endplate (CEP) to maintain its health. IVD degeneration is characterized by loss of PGs, dehydration of the NP, collagen loss within the AF, and degradation of the CEP. Dehydration and calcification of the CEP reduce its diffusivity, leading to a reduction in oxygen and glucose transport to the remainder of the disc. Changes in the CEP may occur at the same time or even precede disc degeneration. Evaluation of this complex situation requires a comprehensive, non-invasive imaging technique that can assess PG in the NP, collagen in the AF, and diffusivity of the CEP. Magnetic resonance imaging (MRI) is routinely used in the diagnosis of IVD degeneration. However, conventional MRI techniques do not provide reliable assessment of disc biochemical content nor of CEP function. This study aims to further develop a 3D ultrashort echo time (UTE) adiabatic T1r (UTE-AdiabT1r) sequence for robust mapping of PGs, a UTE magnetization transfer (UTE-MT) sequence for mapping of macromolecular fraction (MMF), an adiabatic inversion recovery UTE with fat saturation (IR-FS-UTE) sequence for T2* mapping of the CEP to evaluate calcification and dehydration, and a UTE dual echo steady state (UTE-DESS) sequence to study its apparent diffusion coefficient (ADC). In Aim 1 we will develop 3D UTE sequences to evaluate IVD in lumbar spines from young (<40y, n=10), mid-age (40-70y, n=10), and elderly (>70y, n=10) donors, and correlate UTE (AdiabT1r, MMF, T2*, ADC) and clinical MRI measures with reference including CT, µCT, histology, biochemistry, and diffusion test of three groups of spine samples. In Aim 2 we will evaluate 3D UTE sequences to assess IVD degeneration and regeneration using a mature rabbit annular puncture chronic disc degeneration model. We will study IVD degeneration in four groups of rabbits (n=16 per group) at 4, 8, 16, and 28 weeks post-AF puncture, as well as IVD regeneration using six groups of rabbits (n=16 per group) at 4, 12 and 24 weeks post- injection of saline and growth differentiation factor-6 (GDF-6). We will correlate UTE and clinical MRI findings with reference including µCT, histology, biochemistry, and diffusion test of ten groups of rabbit lumbar spines. In Aim 3 we will translate UTE sequences to study IVD degeneration in patients with chronic LBP (n=40) and normal IVDs in healthy volunteers (n=40), compare UTE and clinical MRI metrics of the NP, AF, and CEP of the lumbar spine in the two groups, and correlate them with clinical evaluations. Our central hypothesis is that UTE sequences can detect changes in PG and collagen in the disc as well as changes in diffusivity of the CEP, allowing more comprehensive and accurate evaluation of disc degeneration than is now possible.

NIH Research Projects · FY 2025 · 2022-04

Abstract Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is an incurable genetic based cardiac disease that causes sudden death in young adults and athletes. ARVD/C is termed a “disease of the desmosome” as 40-50% of mutations in ARVD/C patients are found in desmosomal (junctional anchor) genes, with plakophilin-2 (PKP2) being the most frequently mutated desmosomal gene. Evidence suggests that altered RNA splicing may be a critical mechanism through which PKP2 patient genetics drive ARVD/C. However, no models and limited mechanistic insights exist into how human desmosomal mutations in RNA splicing impact ARVD/C and what form of therapeutics would be impactful in these settings. Through CRISPR-Cas9 we generated a novel mouse model globally harboring a human PKP2 mutation (IVS10-1 G>C) that impacts RNA splicing. PKP2 homozygous mutant (PKP2 Hom) mice selectively display all adult hallmarks of ARVD/C including sudden death. RNA and sequencing analyses revealed low levels of a larger PKP2 transcript that retains an intronic sequence. Protein analyses of PKP2 Hom hearts revealed low levels of a higher molecular weight PKP2 mutant protein that was expressed in the absence of endogenous PKP2. Strategies to increase wild type PKP2 and mutant PKP2 protein in PKP2 mutant neonatal cardiomyocytes suggested that splicing effects on PKP2 haploinsufficiency mechanistically drive cell junction deficits in early ARVD/C. Targeted restoration of PKP2 protein dose in neonatal PKP2 Hom mice had therapeutic potential in late ARVD/C as it restored cardiac mechanical junction complex and prolonged life in adult PKP2 Hom mice. PKP2 Hom mice provide an ideal test platform to assess the impact and mechanism of PKP2 restoration in circumventing ARVD/C in classic patient- centric models during early and late stages of disease. Prime editing (search-and-replace) strategies have come to age as novel methods to correct single base mutations and address the “root cause” of ARVD/C, though limited studies have applied this technology towards therapeutic use in disease settings. We hypothesize the PKP2 RNA splicing mutation is sufficient to drive ARVD/C through a mechanism impacting splicing consequences on PKP2 protein dose. PKP2 targeted strategies (gene therapy and prime base editor-directed correction) can be exploited to therapeutically alter ARVD/C. We aim to determine: (i) the pathogenic mechanism by which PKP2 RNA splicing mutations drive ARVD/C, (ii) the impact and mechanism of early and late PKP2 restoration in our novel PKP2 mutant mouse and human ARVD/C models, and (iii) a base editing strategy to correct the PKP2 (IVS10-1 G>C) mutation and assess its impact in our novel PKP2 mutant ARVD/C model.

NIH Research Projects · FY 2026 · 2022-03

Melody K Schiaffino, PhD, MPH is an associate professor in the Department of Radiation Medicine and Applies Sciences in the UC San Diego School of Medicine. Dr. Schiaffino received her PhD in Health Services Research in 2014 and MPH in Epidemiology in 2008. As a health systems scientist, Dr. Schiaffino’s goals are to identify organizational and provider-level risk factors that affect how care is delivered to older adults undergoing treatment for cancer to improve sub-optimal care delivery and treatment outcomes. Older adults are at greater risk due to the higher symptom burden and treatment-related toxicity risk of cancer therapy. The proposal entitled, Improving age-related risk assessment and documentation in older adults diagnosed with cancer, seeks to examine provider and documentation factors that result in sub-optimal assessment of age-related risk. Age-related risk assessments are a series of evidence based clinical tests and screening that can improve cancer treatment planning for older adults, it is especially salient for older adults. There is currently insufficient research on the mechanisms contributing to sub-optimal assessment and documentation of age-related risk in radiation oncology. While evidence supports improved communication and cancer outcomes for patients when age-related risk is assessed, recent clinical trial findings show that only 1 in 4 providers are implementing this assessment in routine practice. Effective assessments are even less common in older adults needing an interpreter. Understanding organizational and provider-level perspectives on assessment and documentation practices using electronic health records (EHRs), and qualitatively interviewing and observing oncologists, will help inform future clinic workflow redesign. The proposed career development and training plan supports Dr. Schiaffino's trajectory toward becoming an independent, aging-systems scientist through the following three goals: 1) Obtain advanced natural language processing (NLP) algorithm development training to extract unstructured text from EHRs, 2) Engage in observation and training in geriatric oncology care delivery, to understand clinical workflow and clinical practices around assessment of age-related risk, and 3) Gain experience in clinical workflow implementation science proposal development. This project will take place at SDSU, UCSD, and City of Hope (Duarte, CA) with mentors who are experts in Geriatrics/Gerontology Geriatric Oncology/ Decision-Making (Mentor: William Dale, MD, PhD, City of Hope); NLP/Bioinformatics (Mentor: Mike Hogarth, MD, UCSD); Radiation Oncology/HSR (Co- Primary: James Murphy, MD, MS, UCSD); Predictive Models/Biostatistics (Collaborator: Barbara Bailey, PhD, SDSU) and clinical implementation science (Co-Mentor: Alicia Fernandez, MD, UCSF).

NIH Research Projects · FY 2026 · 2022-03

Project Summary/Abstract Hoarding disorder (HD) is a chronic, progressive, and debilitating psychiatric condition that leads to devastating personal and community consequences, particularly for older adults. HD is defined by persistent difficulty discarding or parting with possessions due to distress associated with discarding, urges to save, and/or difficulty making decisions about what to keep and what to discard. As a result, clutter accumulates and fills active living areas, preventing the normal use of space and resulting in distress and disability. Community epidemiological reports estimate the prevalence of clinically significant hoarding symptoms at 7% in individuals over age 60 and even higher rates in those over age 70. HD is the only neuropsychiatric condition that progresses in severity and population prevalence with age apart from dementia. Inhibition and cognitive switching have been identified as key deficits in older adults with HD. These executive functioning areas are consistent with the RDoC cognitive control domain and particularly the goal selection, updating, representation, and maintenance subconstruct. Findings suggest that these deficits may contribute to the symptomatic expression of HD, degree of functional impairment, and modest responses to HD treatment. Furthermore, anticipatory and experiential fear and anxiety, consistent with the RDoC constructs of acute and potential threat, lead to sustained problems with discarding items and clutter accumulation. When these constructs are targeted, our group has produced clinically and statistically significant outcomes. Consistent with NIMH strategic goal 3.1, to arrive at effective treatment approaches for unmet therapeutic domains in behavioral science, this project seeks to conduct the first confirmatory efficacy trial for older adults with HD. We propose a RCT comparing CREST to a case management control condition for 150 adults age 50 and older with HD. We are examining age as a moderator and will therefore include both midlife and late life participants. An evaluation of treatment outcome, including hoarding severity and functional outcomes, will be conducted at baseline (0 months), mid-treatment (3 months), end of treatment (6 months), 3-month (9 months) and 6-month follow-up (12 months). Participants will receive 26 weekly 60-minute individual sessions over the course of 32 weeks maximum (6-7.5 months). They will receive 50% in home and 50% office visits. We will examine factors that mediate improvement in CREST (improved inhibition/cognitive switching and reduction in fear/anxiety of discarding items) through physiological, behavioral, self-report, and paradigm assessments. Individual factors (e.g., age and other demographic factors, baseline cognitive control, baseline hoarding severity) and treatment factors (e.g., session attendance) will be evaluated as moderators. The specific aims include determining confirmatory efficacy of CREST, mechanisms of CREST effects, and moderators of CREST. If successful, this project would lead to an effectiveness trial in a real world setting.

NIH Research Projects · FY 2026 · 2022-03

7. Project Summary Inflammatory bowel disease (IBD) arises in genetically-susceptible individuals when the intestinal immune system loses tolerance to unidentified elements of the commensal microbiota. Plasma cell (PC)-derived secretory immunoglobulin A(sIgA) is one of the main mechanisms through which we are able to coexist with our microbiota. Despite this, insufficient emphasis has been placed on understanding the B cell/immunoglobulin A (IgA) system during IBD. Antibodies that block integrins on the cell surface of white cells have become a widely- used strategy for the treatment of IBD. One of these drugs (vedolizumab), specifically blocks integrin α4β7, a molecule which is critical for the traffic of white cells to the intestine. We find that B cells carry this integrin more than T cells in mice and humans and critically depend on this molecule to traffic to intestine. Therefore, mice that lack the β7 integrin chain have an intestinal B cell deficit and a stool IgA deficit that leads to alterations if their intestinal flora and worse IBD in two chronic IBD mouse models. Although this could be attributed to an integrin α4β7 defect, the luminal IgA deficit persists in mice that lack αEβ7 integrin, although in these mice B cells can reach the intestine normally. We recently found a previously undescribed subset of intestinal PC that express αEβ7, localized primarily to the base of the crypts. We propose that certain intestinal PC express αEβ7, which allows them to dock with intestinal epithelial cells and directly relay IgA for its most efficient transport to the intestinal lumen. We believe that this new mode of IgA transport plays a critical role for the maintenance of IgA in intestinal lumen and therefore on the microbial flora during IBD. In the current proposal we will several address important questions that remain unanswered. 1. Where are these cells located and what is their origin? 2. How do they influence the severity of IBD in mice and 3. What is their contribution on the control of the intestinal bacterial flora during IBD. This investigation is significant as it begins to address the role of B cells and their critical dependence on β7 integrins to home to the intestine and maintain the required IgA levels that control certain pathogenic microbes during IBD. Understanding the role of lymphocyte integrins at the interface between the microbiota and its host may lead to a better understanding of how do current anti-integrin therapeutics work and lead to new interventions to prevent the uncontrolled immune response to the microbiota that triggers IBD.

NIH Research Projects · FY 2026 · 2022-03

PROJECT SUMMARY/ABSTRACT Inflammatory bowel disease (IBD) has long been associated with compositional and metabolic changes in the gut microbiota, yet extensive research efforts have failed to identify a single pathogenic microorganism as the causative agent. In this grant, we investigate an alternative hypothesis in which gut inflammation drives adaptations in commensal bacteria that further exacerbates disease in IBD. Though bacterial adaptations are necessary for commensal survival and persistence in the inflamed gut, we currently do not understand how these adaptive strategies alter the function of commensal microbes. These include metabolic and immunomodulatory activities of commensal bacteria that regulate mucosal immune homeostasis in health and disease. Thus, there is a critical need to understand how the inflamed gut environment shapes commensal bacteria metabolism to further exacerbate inflammation in IBD. The long-term goal of this study is to understand how gut bacteria direct immune responses in order to develop rational microbial therapies for inflammatory diseases. Our central hypothesis is that the oxygenated environment of the inflamed gut drives metabolic adaptations in commensal bacteria, resulting in expansion of bacterial strains that exacerbate intestinal inflammation. The central hypothesis will be tested by pursuing three specific aims: 1) define the genetic and functional variation of commensal Bacteroides fragilis in the IBD gut; 2) determine the metabolic adaptations of commensal bacteria during experimental colitis; and 3) identify the impact of oxygen on anaerobic bacterial metabolism and immune modulation. We will examine the genetic variation of B. fragilis strains from healthy and IBD cohorts. This information will enable the construction of strain-specific B. fragilis genome-scale models to elucidate the metabolic output and phenotypic states of IBD-associated strains. Next, we will determine the genetic adaptations of B. fragilis in mouse models of colitis and test the impact of intestinal inflammation on bacterial metabolism and immune modulation. Finally, we will examine how oxygen-adapted strains of B. fragilis may have metabolic and immunological consequences on intestinal homeostasis. The proposed research is significant because defining commensal bacteria adaptations to early stages of gut inflammation will be a powerful strategy for detecting and treating early stages of IBD and preventing progression into the debilitating chronic phase of IBD.

NIH Research Projects · FY 2026 · 2022-03

PROJECT SUMMARY Autism spectrum disorder (ASD), which is usually accompanied of intellectual disability (ID), is part of a group of neurodevelopmental disorders that are usually diagnosed during the first two years of age. The social, emotional and communication skills of affected individuals are severely impaired throughout life and are often accompanied by a spectrum of debilitating symptoms with different degrees of severity including, stereotypic behavioral traits, epileptic episodes, sensory oversensitivity, and impaired motor functions that seriously interfere with their daily life activities. ASD is an important public health concern as it affects 1 in 54 individuals. It occurs in all racial, ethnic, and socioeconomic groups, and in the United States alone, the estimated total cost per year per children is between $11.5 and $60.9 billion. Thus, families with ID/ASD-diagnosed children experience heavy psychological and financial burdens. While early intervention services can significantly improve certain aspects of child's development, no disease-modifying treatments are currently available. Despite enormous efforts, lack of effective therapies is likely due to our poor understanding of the molecular and cellular mechanisms underlying these conditions with exceedingly complex etiology. The number of different types of genetic variations associated with ASD keeps increasing thanks to the improvement in genomic sequencing technology. However, there is still little understanding of how these genetic changes impact cellular and molecular pathways or which brain cell are more affected by these mutations that ultimately result in brain dysfunction associated with ASD. Among them, loss-of-function genetic variations in the SETD5 gene, which is believe to play an important role in the structure of the genome and in regulating expression of neuronal genes. However, there are important knowledge gaps on the molecular and cellular pathways controlled by SETD5 and how ASD-related mutations in this gene could contribute to neuronal dysfunction. We and others started to address these questions by generating Setd5 deficient mice and showed impaired neuronal function and appearance of ASD-like behaviors. However, mouse models are limited to accurately recapitulate not only disease pathologies but also the protracted process of human brain development. Thus, they can lead to misleading hypothesis. To compensate for these limitations, we have modeled for the first time SETD5-related ASD using human induced pluripotent stem cells (hiPSC). Generating neurons from these cells we recapitulated neuronal dysfunction as previously observed in mice models. More importantly, we uncovered new mechanisms inducing this neuronal dysfunction. In particular, we found that astrocytes, which are more abundant and necessary for keeping neurons healthy and connected in the brain, might produce neurotoxic activity. In this proposal, we extensively characterize the molecular and cellular pathways involved in this process and explore novel therapeutic targets to revert or prevent neuronal dysfunction induced by SETD5 mutations. The successful completion of this research will provide an unprecedented view of astrocyte involvement in ASD and potentially revolutionize its treatment.

NIH Research Projects · FY 2026 · 2022-03

PROJECT SUMMARY/ABSTRACT Breast cancer metastasis to the brain is rising in prevalence and is an increasingly lethal threat to patients due to the very limited treatment options and high mortality. Therefore, there is a great and urgent need to develop novel preventive and therapeutic treatments for brain-homing metastatic cancer. Altered function of normal cells in a metastatic niche has been recognized as an important means for cancer to facilitate metastasis. The metabolic reprogramming of normal niche cells during cancer metastasis, however, remains largely unexplored. The proposed project will investigate this unique aspect of cancer–host crosstalk from the novel perspective of extracellular miRNA, whose function in transferring cancer-derived signals to various types of niche cells to facilitate cancer growth and metastasis has been recently recognized. MiRNA negatively regulates gene expression through inducing mRNA degradation and/or translation blockade. The goals of this study are to identify the mechanism by which cancer cell-secreted miRNA reprograms the energy metabolism of brain cells (neurons and astrocytes) to promote metastasis, to assess potential therapeutic strategies to protect the brain using experimental models, and to evaluate the potential of such miRNA as a novel blood-based biomarker for breast cancer brain metastasis. In Aim 1, we will determine the effects and acting mechanism of selected breast cancer-secreted miRNA in the metabolic reprogramming of brain cells and tissues, including a mechanism through suppression of nutrient influxes. Mouse models will be used to elucidate how altered energy metabolism in the brain contributes to the stepwise process of breast-to-brain metastasis. In Aim 2, we will assess the beneficial effects of experimental therapeutics targeting cancer-induced adaptation of the brain as novel strategies to prevent or treat breast cancer brain metastasis. In Aim 3, we will evaluate the potential of circulating miRNA as a clinical biomarker for the prediction or early diagnosis of brain metastasis in breast cancer patients. We will also investigate specimens of resected brain metastases for clinical evidence of the herein identified molecular mechanism. The proposed project will provide a novel perspective to our understandings of the dynamic communication between cancer and host and of the complex mechanisms underlying the development of brain metastases. It may establish rationales for novel therapeutic strategies to prevent or treat brain-metastasizing cancer and alleviate cancer’s adverse effects on brain function, which is our long-term objective. Importantly, our study may establish circulating miRNA as a non-invasive biomarker to identify patients with a high risk of developing brain metastases, thereby enabling a shift of our therapeutic focus to targeting the prevention of brain metastases.

NIH Research Projects · FY 2026 · 2022-03

Single Cell Tracking of 3D Epigenetic Landscape Evolution During Embryonic Development An important question to cell biology is how cells break the symmetry during mitotic divisions. During mammalian pre-implantation embryonic development (PED), how the first cell fate decision is made remains unclear and is crucial for the understanding of how specific gene regulations can guide the life of a cell. Epigenetic modifications including chromatin remodeling are early events during PED. Histone methylation at different residues can recruit differential sets of chromatin remodeling complexes to regulate chromatin structures and silence/activate gene expressions accordingly. These histone methylations and their combinations at different genomic loci can serve as codes to determine the overall gene expression profile and phenotypic outcomes. However, it is still not understood how histone methylations and hence chromatin structures at specific loci are dynamically regulated during PED in which cells undergo a heterogeneous modulation at single cell levels. In this proposal, we will harness the power of directed evolution and high-throughput screening method to systematically develop specific/sensitive FRET (fluorescence resonance energy transfer) biosensors for the monitoring of crucial histone methylations in single cells. We will further develop and apply the mapping RNA-chromatin interactions in single cells (sciMARGI) to identify crucial RNA-genome interaction sites during PED. We will then employ the endonuclease-deficient Cas9 (dCas9), small guide RNAs (sgRNAs) and split FPs to identify and track the positons of specific loci crucial for embryonic cell differentiation. Ultimately, we will apply our controllable epigenetic modulators to guide the histone modulations at specific loci and elucidate their role in determining cell fates during PED. Given the importance of epigenetic modifications at different loci, the success of the project should have transformative impact in understanding the role of locus-specific epigenetics in determining the cell fate during PED. Accordingly, three aims are proposed: Aim 1. Spatiotemporal imaging of crucial histone methylations in single live cells and during PED; Aim 2. Visualize the locus-specific histone modifications during PED; Aim 3. Reprogram the locus-specific histone modifications during PED. While the focus of this proposal is to develop tools targeting histone methylations and chromatin structures at specific loci and differentiation outcomes, the strategies and approaches can be extended to monitor, in principle, any other epigenetic modification in single cells, including but not limited to histone acetylation and phosphorylation. The results from this project can also lead directly to the dynamic nuclear atlas illustrating how specific histone codes are encrypted in an integrative manner for the regulation of life.

NIH Research Projects · FY 2026 · 2022-03

PROJECT SUMMARY/ABSTRACT During adolescence, substance abuse and conduct problems are co-occurring and mutually reinforcing problems with significant acute and long-term burden to adolescents, their families, and society. Family-based treatments and prevention programs can reduce their incidence, but these interventions are limited in the size, duration, and scope of effects and can be cumbersome to implement. One factor limiting the refinement of these existing interventions is the difficulty of conducting rigorous science about the specific causal effects of the family factors that are targeted as mechanisms of change. Factors such as parental monitoring, parental warmth, and family conflict covary with each other as well as many other variables (e.g., genes, socioeconomic status, living environment, parent psychopathology), so it is difficult to isolate their unique impacts on adolescent outcomes from the larger causal network of risk factors. This proposal pursues a causally grounded, mechanistic approach to disentangle the impacts of family processes and characterize how they vary by the severity, chronicity, and developmental timing of exposure at the population level. We draw data from the Adolescent Brain and Cognitive DevelopmentSM (ABCD) Study—a diverse, longitudinal, nationwide, population-based cohort of 11,880 youth ages 9/10 years old followed prospectively until ages 19-20, with simultaneous measurement of many intercorrelated aspects of development at biannual assessments throughout. We will attempt to isolate the effects of parental monitoring, parental warmth, and family conflict from other influences using three distinct, and complementary approaches: (A) a between-subjects approach using marginal structural models; (B) a within-subjects approach using the fixed effects panel estimator; (C) a twin/sibling discordancy approach using 336+ pairs of monozygotic twins, 430+ pairs of dizygotic twins, and 1,805 non-twin siblings. We pursue four specific aims. Aim 1: Determine the causal impacts of three family processes—parental monitoring, parental warmth, and family conflict—on proximal adolescent substance abuse and conduct problems between ages 11 to 18 years. Aim 2: Determine whether the effects of the family processes vary by youth sex, racial/ethnic identification, or predisposition to substance abuse and conduct problems. Aim 3: Determine whether the effects of three family processes vary by severity, chronicity, or developmental timing of exposure. Altogether, this research will yield a more scientifically accurate developmental psychopathology of adolescent substance abuse and delinquency and thereby inform the design, refinement, and personalization of family-based interventions to reduce the incidence of these problems at the population level.

NIH Research Projects · FY 2026 · 2022-03

Functional interplay between Hippo and estrogen receptor ESR1 Project Summary/Abstract The majority of breast cancers are estrogen receptor (ER positive and growth of ER+ cancer is dependent on ER function. Hormone therapy by inhibiting ER is most commonly used for ER+ breast cancer treatment, however, drug resistance develops. There is strong medical need to develop new therapy, particularly for hormone therapy resistant breast cancer. Estrogen receptor 1 (ESR1) encodes the major form of ER and has been extensively studied for its function as a nuclear transcription factor. However, the transcriptional regulation of ESR1 itself is less understood. Preliminary studies from our laboratory have shown that ESR1 expression is tightly controlled by the Hippo pathway, which is known for its role in organ size control and tumorigenesis. Deletion of LATS1/2 kinases, core components of the Hippo pathway, abolishes ESR1 expression and inhibits growth of ER+ breast cancer cells. We further discovered that LATS1/2 suppress cancer cell immunogenicity. This proposal is based on our novel and exciting observations. A major goal of this project is to reveal the molecular mechanism of ESR1 transcription regulation by the Hippo pathway and the functional significance of ESR1 in mediating Hippo biology in breast tissue. Furthermore, we posit that LATS inhibition has two effects on ER+ breast cancer: suppression of cell growth by reducing ESR1 expression; and enhancing the efficacy of immunotherapy by increasing cancer cell immunogenicity. The second major goal is to provide scientific basis for targeting the LATS1/2 kinases as a novel therapy for ER+ breast cancer.

NIH Research Projects · FY 2026 · 2022-02

TITLE Mechanisms of protection from noise-induced hearing loss ABSTRACT The cellular and molecular bases underlying noise-induced hearing loss (NIHL), the second leading cause of hearing loss globally, are to date, not understood presenting a barrier to the prediction of risk, the prevention, and ultimately the treatment of this debilitating disease. 1.1 billion young people (aged between 12-35 years) are at risk of hearing loss due to exposure to noise in recreational settings. Among Service Members of Operation Enduring Freedom and Iraqi Freedom, NIHL and its associated tinnitus are the top two diagnoses and unaddressed hearing loss poses an annual global cost of $750 billion US dollars. Noise attenuation and hearing aids currently represent the only measures for protection and treatment, respectively. It is now clear that cochlear synaptic loss precedes hair cell loss at low-moderate noise exposures (nonexplosive) effectively silencing affected neurons. Our laboratory and others have illuminated genetic mechanisms that modify sensitivity to NIHL in mice and humans. Through mouse GWAS we have identified a critical gene, Prkag2 encoding the g2 subunit of the AMPK complex. We find that damaging noise leads to nuclear AMPK activity specifically in inner hair cells and that Prkag2 deficient mice are susceptible to NIHL due to greater instability of the inner hair cell presynaptic ribbon. There is an urgent need to identify directed therapies aimed at the prevention and/or repair of cochlear damage from noise exposure, for which an understanding of the underlying mechanisms is an obligate prerequisite. Toward the long-term goal of developing targeted therapies for the prevention and/or correction of noise-induced synaptopathy, we now seek to decipher the pathways and mechanisms linking nuclear AMPK activity in inner hair cells to NIHL. Based upon our preliminary data, our central hypothesis is that AMPK becomes activated and trapped in the nucleus of inner but not outer hair cells by intranuclear phosphorylation after noise exposure and subsequently regulates the expression of downstream targets that impact the number and volume of presynaptic ribbons. Using a combination of genetics, physiology, cell biology, biochemistry, and structural biology, we propose the following three aims: the identification of cellular factors associated with susceptibility to NIHL (Aim 1), the molecular basis of nucleocytoplasmic shuttling of AMPK (Aim 2), and the identification of additional factors in the AMPK pathway leading to susceptibility to NIHL (Aim 3). As the AMPK pathway is fundamental to cell survival, metabolism, gene regulation, and hearing, and is targetable, the completion of these aims has the potential to lead to meaningful interventions for this debilitating condition.

NIH Research Projects · FY 2026 · 2022-02

Uncontrolled activation of the IkappaB kinase (IKK), the key cellular regulator of NF-­κB, causes a variety of disorders, including susceptibility to pathogenic infection, autoimmunity, inflammation-­induced malignancies, and inflammatory syndromes. However, targeting the IKK-­NF-­kB signaling pathway has not yielded any new strategies for fighting inflammatory illnesses. The lack of understanding of how IKK becomes activated in response to various stimuli is the fundamental reason for our failure to exploit this unambiguous target. The IKK complex is made up of three subunits, catalytic IKK1 (also known as IKKα) and IKK2/β kinases, which form a heterodimer, and the dimeric scaffolding protein NEMO (NF-­κB Essential Modulator), which is stably bound to the heterodimer. In vitro and in cells, this fundamental tetrameric unit of the IKK complex (IKK1:IKK2:NEMO2), emerges as significantly higher molecular weight multimers. The catalytic activation of IKK2, referred to as canonical signaling, requires linear (M1-­linked), K63-­linked, or mixed poly-­ubiquitin chains (Ub-­chain) that engage noncovalently with the NEMO subunits. The mechanism by which this binding information is transferred from NEMO:Ub-­chain interaction to yield IKK2 subunit phosphorylation and subsequent activation of IKK is unknown. We hypothesize that multimerization via dimer-­dimer interaction is required for IKK2 activation and that the tetramer interface stabilizes the native IKK complex, allowing NEMO to undergo conformational changes upon binding to the Ub-­chain. The kinase domain of the IKK2 subunit is activated as a result of structural alterations in NEMO. Disease-­causing NEMO mutations or mutations at the tetramer interface do not support the assembly and Ub-­chain-­dependent NEMO conformational changes required for IKK activation. In support of our hypothesis, we have already shown that a short peptide segment derived from NEMO interacts with IKK2 in a signal-­dependent manner and that IKK multimerization requires short homologous peptide segments within IKK1 and IKK2. Under this proposal, we will achieve the following specific aims: AIM 1. We will characterize the dimer-­dimer interface which is required for IKK multimerization. We will use disease-­causing NEMO mutants and IKK multimerization-­defective mutants to test how the structural plasticity of NEMO is linked to IKK2 activation. AIM 2. We will determine if the IKK1-­ and IKK2-­derived peptides disrupt dimer-­dimer interaction and IKK2 activation in cells and in vivo. We will test if the IKK-­derived peptides independently and in combination with the NEMO-­derived peptide can ameliorate systemic inflammation and collagen-­induced arthritis in mouse models.

NIH Research Projects · FY 2025 · 2022-02

Project Summary Vascular endothelial cell (EC) metabolism is essential for functional endothelium, and maladapted energy use severely affects EC health. AMP-activated protein kinase (AMPK) is a key regulator of cellular energy status and homeostatic function. Our preliminary studies showed that energy stress results in spatially defined AMPK activity at cellular organelles, which indicates that AMPK activity is compartmentalized in the cell. An emerging AMPK substrate in the vascular endothelium is angiotensin-converting enzyme 2 (ACE2), and we have found that the AMPK–ACE2 axis enhances EC function and is atheroprotective. SARS-CoV viruses invade the host cells by binding the viral spike protein (S protein) to ACE2, which leads to decreased membrane ACE2 levels, increased extracellular soluble ACE2, and increased glycolysis, thus resulting in host cell damage. In preliminary studies, we have also found that the SARS-CoV-2 S protein deactivates the AMPK–ACE2 axis and impairs EC function in vitro and in vivo. This impairment is likely to constitute a risk factor for the long-term effects of SARS- CoV-2 infection or post-acute sequelae of SARS-CoV-2 infection (PASC). These preliminary findings lead to the hypothesis that EC homeostasis is maintained via the spatiotemporal regulation of the AMPK–ACE2 axis. In contrast, S protein entry disrupts cellular energetics in ECs, leading to dysregulated AMPK and the ensuing ACE2 hypo-phosphorylation, which critically contributes to the COVID-19–associated EC dysfunction and PASC. The three specific aims proposed to test this novel hypothesis are as follows: Aim 1. To investigate the spatiotemporal regulation of AMPK in ECs under physiological [e.g., pulsatile shear stress (PS)], pharmacological (e.g., metformin), and pathophysiological (e.g., S protein) conditions; Aim 2. To decipher the mechanisms by which physiological, pharmacological, and pathophysiological stimuli modulate the AMPK– ACE2 axis in ECs; Aim 3. To investigate the role of impaired AMPK–ACE2 axis in S protein-accelerated atherosclerosis in the context of PASC. In the proposed research, we will use live cell imaging, in vitro EC biology, and in vivo animal models to determine the role of the AMPK–ACE2 axis in endothelial health and disease. These findings will result in otherwise missing insights into the pathophysiology of PASC, which will continue to be a long-term consequence of SARS-CoV-2 infection.

NIH Research Projects · FY 2026 · 2022-02

PROJECT SUMMARY/ABSTRACT The etiology of eating disorders (ED) is complex, yet largely unknown, resulting in a profound lack of effective treatments and a “crisis in care”. Common to EDs are alterations in the motivation to eat, ranging from extreme food restriction and weight loss, to binge eating coupled with compensatory strategies like self-induced vomiting. Despite the traditional emphasis on diagnostic differentiation based on these physical symptoms, they often overlap, and, along with significant diagnostic crossover (e.g., from anorexia nervosa to bulimia nervosa) over time, suggest shared features that are not well captured by current diagnostic criteria. Persistence of restricted eating, binge eating and/or purging despite negative consequences, along with evidence of altered reward and punishment sensitivity in ED, raise the question of whether a failure to appropriately process and/or learn from rewarding and/or punishing experiences might contribute to repeated engagement in maladaptive approach and avoidance behavior and illness maintenance. This is the first study to apply a multi-dimensional framework of reward processing to ED, by examining how the interplay of RDoC-based Positive Valence measures of `liking' (i.e., the hedonic impact of reward consumption), `wanting' or incentive salience (i.e., motivation to pursue a reward), and learning (i.e., the acquisition of reward-outcome contingencies), which are associated with distinct frontostriatal neurocircuitry, differ across ED subtype and correspond to clinical symptoms at baseline and one year later. We will study 150 demographically-matched women with ED (50 AN-restricting type (AN-R), 50 AN- binge eating/purging type (AN-BP), 50 bulimia nervosa (BN)) and 50 healthy controls (HC) aged 18-35. During fMRI, participants will complete 1) a modified monetary incentive delay (MID) task to assess group differences in both neural anticipation (`wanting') and receipt (`liking') of rewarding and aversive disorder-specific (taste) and generalized (money) stimuli (Aim 1), and 2) a probabilistic associative learning task to assess decision-making and instrumental learning from monetary wins and losses (Aim 2). Aim 3 will examine interactions between `liking', `wanting' and learning and associations with symptoms at study entry and 1 year later. An Exploratory Aim will examine associations of dopamine function, as measured by neuromelanin MRI (NM-MRI), with ED diagnosis and brain response to `liking', `wanting', and learning to further inform mechanistic models of reward in ED. This study is innovative and significant in several ways: 1) it adopts a multi-dimensional framework of reward processing to examine independent and interactive contributions of understudied, yet critically important constructs (e.g., `liking', `wanting', learning) in ED, 2) it assesses the role of stimulus modality (taste, money) and valence in `liking' and `wanting', and 3) relates these constructs to actual symptoms and behavior at study entry and 1 year later to understand what drives shared and divergent symptoms and predicts symptom change, which has potential for substantial clinical impact. Identification of dimensional constructs underlying symptoms and their neural correlates is critical to improve a mechanistic understanding of ED and advance precision medicine.

NIH Research Projects · FY 2025 · 2022-02

Abstract The COVID-19 pandemic has led to massive challenges for health care systems and for global economics. The surge in cases which occurred abruptly strained the existing resources to care for the volume of patients, leading to a shortage of supply in many medications, personnel and equipment. The mechanical ventilator became a particular problem as one newly published study reported that 18 out of 24 patients with COVID-19 in the study (75%) required mechanical ventilation. During the early months of the pandemic many providers decided to intubate early on the assumption that patients would eventually need mechanical ventilation so as to avoid ‘crash intubation’ and potential contamination. A recent observational study of intensive care unit patients with COVID-19 suffering from acute hypoxemic respiratory failure revealed that early invasive mechanical ventilation was associated with an increased risk of day-60 mortality. One central problem in this context was caregivers’ inability to predict which patients may need mechanical ventilation since existing methods using clinical parameters are often subjective and inconsistent across different institutions. We have thus applied machine learning algorithms to commonly available data in electronic health records (EHR) to develop and validate a predictive model for 24-hours ahead prediction of respiratory failure. This novel predictive model has demonstrated AUCs in the range of 0.90-0.94 in our internal and external COVID-19 datasets. That is, we have a robust ability now to predict which patients may need mechanical ventilation and which will not. We are now planning to deploy clinically and to improve iteratively on our model by adding other data streams such as imaging to not only improve our predictive ability but also to make the predictions more ‘actionable’, so that clinicians can pursue timely interventions rather than just being told a prognosis. We are further addressing the many barriers to implementation by addressing ‘clinician buy-in’ which involves making the underlying reasoning of our algorithms more transparent, making the predictions seamlessly integrated into clinical workflow, and finding actionable parameters that will allow both predictions and therapeutic interventions. Such an algorithm will enhance the ability of clinicians to estimate the risk for respiratory failure, and ideally, to anticipate and respond to patient needs in a timely fashion. Moreover, given a long enough prediction horizon (48-72 hours) such systems can facilitate triage and optimization of related resources (ventilators and personnel) within a given hospital and across healthcare systems. Finally, while the COVID-19 pandemic highlighted the need for optimizing the timing of mechanical ventilation, the techniques developed under this proposal are broadly applicable to other causes of respiratory failure and to other types of organ support technologies.