University Of Miami School Of Medicine

NIH Research Projects · FY 2026 · 2024-12

ABSTRACT This proposal addresses an urgent need to understand and analyze the impact of environmental factors on the development of psychiatric diseases, such as depression. Adolescents are particularly vulnerable to both developing depression and health impacts of environmental exposures. Emerging evidence suggests that exposure to polychlorinated biphenyls (PCBs) may influence the risk of depression. PCBs are highly pervasive in the environment and biota due to their widespread use, careless disposal, and resistance to degradation. Moreover, recent data demonstrates widespread human exposure to, not only legacy, but also “contemporary” PCB congeners that are unintentional byproducts of current manufacturing processes. A widespread PCB contamination has been identified in schools, highlighting the importance of evaluating the role of PCB exposure on the development of depression in adolescence. Indeed, there is a critical gap of knowledge on the impact of PCBs on depression. The present application is intended to close this gap using adolescent mouse models. The central hypothesis of this proposal is that PCB exposure in adolescence primes for depression. Mechanistically, we will focus on the gut microbiome- brain axis because of the evidence that gut bacteria influence depression and exposure to PCBs induces both the gut dysbiosis and dysfunction of the blood-brain barrier (BBB). We propose the following sequence of events, which will be studied in mouse models chronically exposed to PCBs: gut dysbiosis and disruption of the gut barrier (Aim 1) → dysfunction of the BBB and neuroinflammation (Aim 2) → development of depressive syndromes (Aims 1 and 2). Our translation objective is to demonstrate that exposure to a human-relevant PCB mixture contributes to, and accelerates, the pathomechanisms of depression via the gut microbiome-brain axis and chronic brain neuroinflammatory responses. The significance of our proposal is in its focus on leading public health problems in the US, namely depression in adolescents. The impact of PCBs on the development of depression is largely unknown, making the proposed studies innovative and likely to generate unique data sets. The discoveries resulting from this proposal are expected to have significant epidemiological, economic, and social implications. Knowledge of the underlying mechanism(s) whereby PCBs prime individuals to depression may provide novel targets for pharmacological intervention. As such, outcomes of this application will close a crucial knowledge gap and provide critically important and therapeutically relevant information on the involvement of environmental toxicants in the development of depression in adolescents. Our long-term goal is to characterize how environmental exposures contribute to the pathomechanisms of depression in adolescents and, ultimately, prevent its development through a precision environmental health intervention.

NIH Research Projects · FY 2024 · 2024-12

Abstract Chronic kidney disease is one of the most prevalent diseases around the world, affecting over 35 million people in the United States alone. Of these, roughly 15% of cases are attributed to glomerular diseases such as Alport Syndrome (AS), which progresses to end stage renal disease in 90% of patients by the age of 40. Despite knowing the genetic underpinnings of AS, the downstream mechanisms are not fully understood, making it difficult to create targeted therapies for patients. Work from us and others have implicated the dysregulation of sphingolipid metabolism and signaling in the progression of glomerular disease via injury to the podocyte, a specialized glomerular cell which is crucial for renal filtration. The involvement of sphingosine-1-phosphate (S1P), a highly bioactive sphingolipid, is implicated in glomerular pathology. We have shown that the expression of Apolipoprotein M (ApoM), the physiologic carrier of S1P, is inversely correlated with albuminuria in CKD patients. Similarly, our preliminary studies show an association between ApoM deficiency and podocyte/renal injury in vitro and in vivo. Aim 1 will investigate if ApoM deficiency exacerbates S1P-mediated podocyte injury. Our preliminary data show that Col4a3-/- mice, a model of AS, have significantly decreased APOM in the renal cortex, mirroring the phenotype in human patients. Furthermore, they also show S1P accumulation in kidney cortex in association with glomerular apoptosis, while treatment with recombinant APOM restores these phenotypes and improves renal function. This aim leverages lipidomic analyses, advanced microscopy modalities, and renal phenotype evaluation to determine the role of S1P in mediating podocyte injury. This aim will use various in vitro and in vivo analyses in lentiviral siAPOM cells and renal APOM deficient kAPOMASO-/- mice to establish the role of kidney- derived APOM in modulating S1P content and downstream podocyte injury. Aim 2 will Determine if renal ApoM replenishment is sufficient to rescue from S1P-mediated renal injury associated with AS. Our preliminary data show that treatment of Col4a3-/- mice with rhApoM in vivo prevents the progression of kidney injury. Importantly, Col4a3-/- mice have decreased ApoM expression in the kidney cortex, while treatment with rhApoM restores renal ApoM expression in vivo. We hypothesize that kidney derived ApoM plays a role in preventing S1P accumulation and consequent glomerular injury in AS. This aim seeks to show that restoring the expression of ApoM in Col4a3-/- podocytes will be sufficient to protect from S1P-mediated injury and restore S1P levels in vitro. We also expect that restoration of renal ApoM expression with AAV gene delivery will prevent progression of proteinuria in Col4a3-/- mice.

NIH Research Projects · FY 2026 · 2024-12

Project Summary Stress often has deleterious effects, particularly in the context of chronic stress, when harm to the individual occurs and often leads to the development of psychiatric diseases. A better understanding of mechanisms mediating stress is critically needed to develop new interventions. In this project, we propose to determine if quorum sensing molecules (QSMs) used by bacteria to communicate, mediate the mammalian stress response. This is particularly relevant in the context of stress as stress has been shown to alter microbiome composition and behaviors. Herein, we propose to determine the physiological role of the QSM, autoinducer-2 (AI-2) in stress- related behaviors. Our overall hypothesis is that AI-2 is key in controlling behaviors because it senses and controls gut bacterial levels and community behavior, as well as integrates and regulates the host response to stress. Specific Aim 1 will test the hypothesis that production of gut bacterial AI-2 is regulated by stress. We will determine whether stress signals produced by the mammalian host (e.g., corticosterone, catecholamines, metabolites) are responsible for the change in AI-2 production by bacteria. Specific Aim 2 will test the contribution of bacterial AI-2 to stress-related behaviors. We will identify bacterial species and metabolites regulated by stress or AI-2 modulation and use engineered E. coli either producing large amount of AI-2 or in contrast scavenging AI-2 from the environment to test their contribution to stress-related behaviors. Finally, Specific Aim 3 will test the hypothesis that bacterial AI-2 induces Th17 cells, microglial changes, and dendritic spine density reduction. We will analyze downstream effectors of bacterial AI-2 on neurobiology, concentrating on the Th17 cells, microglia, and dendritic spine density Altogether, we expect to demonstrate that bacterial AI-2 is a novel signal implicated in the gut-brain axis controlling stress behavioral response. The knowledge gained from these studies might open new avenues for innovative microbiota-based therapeutic strategies for stress-related disorders.

NIH Research Projects · FY 2024 · 2024-11

PROJECT SUMMARY Black women have the highest breast cancer death rates among all racial and ethnic groups, with a 40% higher mortality compared to White women. The burden of breast cancer has surged in the US and in countries in Latin America and the Caribbean. One-third of South Florida's Black population identifies as Haitian and/or Afro-Caribbean. Previous studies have shown that Haitian women diagnosed with breast cancer in Haiti fare significantly worse than Haitian immigrants in Miami, marked by advanced stage and younger age diagnosis, more ER-negative tumors, and limited access to vital treatments. These findings underscore the significance of healthcare access and treatment modalities, yet the differences in age and types of tumors suggest potentially distinct disease pathways as a driver. This raises the question as to whether there are short-term effects of immigration on breast cancer incidence and biology amongst Haitian women with breast cancer in Haiti and in Miami. In this proposal, I aim to leverage existing methylation data on the saliva and tumors of Haitians with breast cancer living in Haiti, living in the US, and of US-born Black women living in the US, to evaluate the effects of immigration on their methylation profile and subsequent tumor characteristics. Additionally, in our cohorts of Black women with breast cancer we observe survival disparities between the Afro-Caribbean and US-born groups. Preliminary analysis of breast cancer outcomes amongst Black patients at the University of Miami showed that Haitian patients had worse overall survival compared to other Caribbean countries. We observed similar poor outcomes for USB women compared to other Caribbean immigrants. Haitian immigrants, as a triple minority group—Black, foreign-born, often speaking Haitian Creole—face unique challenges that may lead to higher levels of stress and discrimination compared to other Black immigrant groups. In this proposal, I will leverage access to the African Cancer Genome Registry to assess the association between perceived stress and discrimination and aggressive tumor characteristics (receptor status, advanced disease) amongst Black immigrant women in Miami, with country of birth and language as mediators. This study will uncover the intricate layers of stress and biologic influences (output as epigenetic) shaping the survival odds of Haitian immigrant women with breast cancer, highlighting their unique challenges within the broader landscape of Black immigrant health disparities. The interdisciplinary nature of this study will allow me to gain essential skills for examining health disparities through an intersectional lens, as articulated by the NIMHD research frameworks.

NIH Research Projects · FY 2025 · 2024-09

We propose to prospectively investigate the effects of cannabis—the most used illicit drug in teenagers— on reward and pain neurocircuits in adolescents with depression. Converging data suggest that cannabis use during adolescence results in long-lasting alterations in reward circuitry, as well as depression and substance use. Alarmingly, epidemiological evidence indicates high use of cannabis among depressed adolescents to self- medicate, potentially exacerbating reward dysfunction, leading to depression chronicity. However, research in this particular cohort has been sparse due to the exclusion of cannabis use in most depression studies. This research seeks to address this knowledge gap. Our proposed model is: (1) Reward dysfunction contributes to depression chronicity. (2) The habenula (Hb), a small limbic hub within the pain circuitry, has been hypothesized to play a role in depression due to its regulatory role in reward function, specifically, inhibiting reward signaling following pain and loss. (3) Cannabis, particularly Δ9-tetrahydrocannabinol (THC), exerts psychoactive and analgesic effects by binding to cannabinoid receptors throughout the reward and pain systems including in the Hb; this leads to temporary relief of mood and pain symptoms but also to alterations in both neurocircuits that may potentiate depression chronicity and substance use. (4) Advancements in fMRI resolution and our novel imaging methods allow us to study the Hb and other small structures critical to reward and pain. In support, we documented that among adolescents with depression, anhedonia—which reflects reward dysfunction—was associated with worse outcomes, including suicidality and chronicity. Additionally, using the reward flanker (RFT) and reward prediction error (RPET) fMRI tasks, we identified distinct brain activity during reward anticipation, attainment, and prediction errors, and found that the latter predicted worse outcomes in depressed adolescents. Further, our Hb imaging methodology allowed us to detect Hb activation during a pain fMRI task and to map Hb intrinsic functional connectivity (iFC) during rest with regions critical to reward, pain, or both. Preliminary data further suggest disrupted Hb connectivity with the default mode network in adolescents with depression and cannabis use. Expanding upon this work, we will test the overall hypothesis that depression and cannabis use in adolescents have an additive effect, inducing alterations in reward and pain neurocircuits, and that this pattern will predict worse depression at 2-year follow-up. We will study 250 adolescents across a wide range of depression and cannabis use severity, including those with subthreshold and no symptoms, as well as 30 healthy controls. Comprehensive clinical evaluations, including daily surveys of cannabis use, as well as blood and urine tests for quantification of cannabinoid metabolites (e.g., THC:CBD) will be conducted at baseline, 12-, and 24- months. Neuroimaging (RFT, RPET, pain, rest) will be acquired at baseline and 12-months. Public health impact: Understanding the relationships between cannabis use and depression in adolescence may inform prevention and intervention strategies for this vulnerable population.

NIH Research Projects · FY 2025 · 2024-09

ABSTRACT AD is the leading cause of dementia in the elderly in all ethnic and racial groups, but most genetic studies for AD are in non-Hispanic Whites (NHW) of European ancestry, resulting in a lack of generalizability of findings across more diverse ancestries. This is problematic, as initial studies in African Americans (AA), who have a higher prevalence of AD compared to NHW, have already revealed differences in risk effect sizes in known loci (e.g., APOE; ABCA7), indicating multiple unique patterns of risk. Therefore, the Alzheimer's Disease Sequencing Project (ADSP) aims to encompass the richest possible ethnic diversity and currently includes over 55,000 funded samples for whole genome sequencing (> 19,000 NHW, >14,000 HL ancestry, and > 8,000 African Ancestry cases and controls). Thus, in this ADSP-FUS 2.0 application, which focuses on the PAR-21-212 goal to increase diversity cohorts in the ADSP, we are proposing generating whole genome sequencing, AD plasma biomarkers and cardiovascular disease biomarkers in an additional ~9,000 individuals of African ancestry (~5,000 African, ~4,000 African American) ascertained as part of the ongoing “Recruitment and Retention for Alzheimer's Disease Diversity Genetic Cohorts in the ADSP” (READD-ADSP U19 AG074865). Further, we will acquire MRI data from 200 Nigerian participants. We will perform longitudinal follow-up visits on mild cognitively impaired and cognitively unimpaired individuals after ~4 years to further evaluate clinical and biomarker level changes longitudinally associated with status conversion. This increase in sample size enhances our ability in this proposal to detect and analyze rare genetic variants contributing to the risk and protection of AD in individuals of African ancestry and understand underlying risk correlated with cardiovascular disease risk and AD plasma biomarkers. Taken together, this project will leverage the resources collected under the READD-ADSP to begin to unravel the AD risk for individuals of African ancestry while providing an invaluable resource for the AD research community at-large.

NIH Research Projects · FY 2025 · 2024-09

Revised PROJECT SUMMARY Glaucoma is a leading cause of irreversible blindness in the United States. Many individuals face barriers in accessing timely and effective diagnostic services, which often leads to late-stage presentation and a substantially increased risk of blindness. This underscores the need for the development of affordable and accessible screening approaches for glaucoma. Although imaging technologies such as spectral domain-optical coherence tomography (SDOCT) can provide highly reproducible and accurate quantitative assessment of glaucomatous damage, their use in widespread screening is limited by high cost and operational complexity. Fundus photography is a low-cost alternative that has been used successfully in teleophthalmology. However, subjective grading of fundus photos for glaucoma is poorly reproducible and frequently inaccurate. We propose a new paradigm for assessing glaucomatous damage by training a deep learning (DL) convolutional neural network to provide objective quantitative estimates of neural damage from fundus photographs. In our Machine-to-Machine (M2M) approach, a DL network analyzes fundus photos to predict quantitative measurements of glaucomatous damage provided by SDOCT, such as retinal nerve fiber layer (RNFL) thickness. Our preliminary results showed that the M2M predictions have very high agreement and correlation with original SDOCT observations. Most importantly, the M2M was shown to detect glaucoma, predict damage in suspects, and track longitudinal change with performance comparable to SDOCT. In this proposal, we aim to refine and validate the M2M model for opportunistic, population-based and community-based glaucoma detection. In Aim 1, we will refine the M2M model using large clinic- datasets, applying innovative frameworks such as vision transformers and generative AI to improve accuracy and robustness for screening applications. In Aim 2, we will implement the M2M model for opportunistic glaucoma screening at the Bascom Palmer Eye Institute (BPEI) eye-specific emergency room (ER), the highest volume eye-specific ER in the nation. This ER serves a large adult population that may not otherwise undergo routine screening. We hypothesize that the M2M model will be feasible to implement and will show high acceptance and diagnostic accuracy. In Aim 3, we will apply the M2M model for detecting glaucoma in population-based datasets and also in a community-based screening program that reaches individuals across several counties in South Florida. We hypothesize that the model will demonstrate high accuracy for glaucoma detection and will outperform clinician-based assessment. This proposal harnesses the power of AI to bridge current gaps in glaucoma care. If successful, it will validate a scalable tool that can be seamlessly integrated into various healthcare settings to support early and accurate glaucoma diagnosis.

NIH Research Projects · FY 2024 · 2024-09

ABSTRACT HIV infection results in increased susceptibility to ischemic stroke by enhancing the injury volume and decreasing post-stroke recovery. Stroke is the second leading cause of death worldwide with a mortality rate higher than 5 million deaths per year. However, the specific factors involved in HIV-induced potentiation of ischemic stroke have not been defined. Inflammatory chemokine CCL2 is known to play a crucial role in HIV infection by acting via the CCR2 receptor, inducing inflammatory responses, including the release of CCL5, and enhancing the blood brain barrier (BBB) disruption during ischemic stroke. Importantly, it has been shown that astrocytes are responsible for the exacerbated CCL2 release post-ischemic stroke. The central hypothesis of this proposal is that astrocyte-specific CCL2/CCR2 signaling modulates HIV-associated stroke severity and functional recovery by regulating monocyte recruitment to the BBB, inflammasome activation, and modulating innate immune responses. Consistent with this hypothesis, the Specific Aims are: 1) To evaluate the hypothesis that astrocyte-derived CCL2 plays a critical role in the recruitment of proinflammatory HIV-infected monocytes/macrophages into the brain, BBB breakdown, and potentiation of ischemic stroke injury in HIV infection. 2) To evaluate the hypothesis that therapeutic targeting of the CCR2 and CCR5 receptors protects against ischemic stroke in HIV-infected brain and accelerates functional recovery via astrocyte-specific innate immunity mechanisms. The proposed research will involve a novel conditional and astrocyte-specific CCL2-deficient mice, namely, CCL2flox/flof;GFAP-Cre conditional knockout mice generated in our lab. Mice will be infected with a mouse adapted to HIV strain called EcoHIV. We will investigate whether conditional ablation of CCL2 in astrocytes can reduce exacerbated neuroinflammatory response. Moreover, we will therapeutically target the CCL2 signaling in humanized mouse model of HIV infection by using the dual CCR2/CCR5 inhibitor cenicriviroc, which can prevent BBB dysregulation through NLRP3 inflammasome inhibition. Next, we will assess both the acute and long-term effects of cenicriviroc on ischemic stroke outcomes. This proposal is conceptually innovative by being the first to study mechanism-targeted therapeutic approaches for BBB protection in the context of stroke in HIV infection. The results of this proposal will significantly contribute to a better understanding of the interplay between the recruitment and infiltration of monocyte subsets into the ischemic brain and the severity of ischemic stroke outcomes in HIV patients. The findings resulting from this proposal will help to establish associated pathways that may be identified as promising new therapeutic targets.

NIH Research Projects · FY 2025 · 2024-09

PROJECT SUMMARY or ABSTRACT Project Abstract/Summary: Career Goal. My long-term career goals are: (1) to obtain and secure a full-time tenure track faculty appointment and (2) become an independently funded public health researcher who partners with public and private stakeholders to assess the health impact of natural events, and produce evidence-based, tailored interventions, and systems change to reduce the overall burden of HIV mortality and environmental determinants of HIV care, especially among African-Americans, Latino/a, highly mobile groups, and other groups facing healthcare barriers and poor health outcomes. Career Development. This K01 research and training plan will catalyze my efforts to acquire the advanced training necessary to develop and plan an intervention addressing the links between natural events and HIV treatment adherence and continuity. My training goals consist of (1) pursuing advanced training in longitudinal statistical quantitative methods necessary to examine the long-term impacts of natural events on the health of people with HIV (PWH); (2) acquiring expertise in the application of Social Network Analysis (SNA) methods to identify the networks that facilitate and limit HIV treatment continuity and ways to leverage networks to improve natural event related HIV care continuity; and (3) developing advanced competencies in implementation science to design an intervention prototype for an R01 network intervention. Research Project. This proposed five-year mixed-methods project explores the health implications of natural event-driven displacement for PWH in San Juan, PR. It aims to establish the link between natural event-related displacement and PWH's continuity of care and mental health. The study addresses how HIV providers, PWH, and organizations respond to natural events to bridge service gaps amid temporary or permanent displacement. Employing SNA and longitudinal analysis it investigates how strategies at individual, community, and government levels can be created with social network to improve HIV treatment continuity and mental health support during natural events. Specific Aims. Aim 1. Determine the displacement generated by natural events and the impact on HIV and mental health care in PR. Aim 2. Identify the role of social networks related to natural event response for HIV and mental health care continuity in PR. Aim 3. Systematically develop an intervention prototype, implementation, and dissemination plan for HIV care continuity around natural events using the 6 quality steps for intervention development (6SQuID) model in conjunction with the Health Promotion Research Center for (HPRC) Dissemination Framework. Mentorship Team: My efforts will be guided by an accomplished, interdisciplinary team of mentors committed to support my transition to an independent investigator.

NIH Research Projects · FY 2025 · 2024-09

PROJECT SUMMARY Effective wound care is of paramount importance for individuals who have sustained burn injuries. Wound healing is intricately associated with the sensations of itching and pain, which can significantly impact a patient's quality of life. Following a burn injury, monocyte-derived Langerhans cells (LCs) are mobilized from the bone marrow and recruited to the epidermal layer, potentially playing a pivotal role in the wound healing process. Furthermore, the sensations of itch and pain are largely mediated by the free nerve endings of nociceptive sensory neurons, often found in close proximity to resident LCs within the epidermis. However, our comprehension of how LCs modulate wound healing, itching, and pain remains notably limited, primarily due to the absence of established methods for selectively manipulating LC activity. Here, we hypothesize that distinct subsets of LCs mediate wound healing, itch, and pain after burn injury. To test this hypothesis, we have successfully applied optogenetics to directly control the activity of LCs by establishing a mouse line that selectively expresses light-sensitive cation channels (ChR2) in LCs. We have also successfully applied chemogenetics to directly control the activity of LCs by establishing a mouse line that selectively expresses Gq- or Gi-biased Designer Receptors Exclusively Activated by Designer Drugs (Gq- or Gi- DREADD) in LCs. The long-term goal of this application is to advance our understanding of the molecular mechanisms behind wound healing, itch, and pain after burn injury regulated by LC-sensory neuron interaction and to offer innovative ways to treat these conditions by targeting LCs. Aim 1 will determine the role of LC-sensory neuron interaction in wound healing using hematopoietic chimeras in which monocyte- derived LCs selectively express Gq- or Gi-DREADD and transgenic mice in which sensory neurons selectively express Gq- or Gi-DREADD. Aim 2 will determine the contribution of LCs to postburn itch and pain using hematopoietic chimeras in which resident LCs selectively express ChR2 or Gi-DREADD, and in vitro calcium imaging from LCs. Aim 3 will genetically define the heterogeneous population of LCs involved in wound healing or nociception after burn injury using single-cell RNAseq. This proposal will help us to understand completely new roles for LCs and how they may regulate wound healing and wound-related itch and pain after burn injury. The successful completion of this proposal would provide a unique approach to treating wound healing, wound-related itch, and pain after burn injury by targeting distinct subsets of LCs.

NIH Research Projects · FY 2025 · 2024-09

Project Summary Cerebral small vessel disease (CSVD) is thought to be among the most prevalent central nervous system disorders and contributes significantly to vascular cognitive impairment and dementia. However, our understanding of the fundamental mechanisms is limited due to technical constraints hindering direct examination of cerebral small vessel integrity. Currently, we rely on MRI scans to detect white matter hyperintensities as a marker of CSVD, but this method lacks sensitivity and specificity. Although it is difficult and expensive to use imaging tests on the brain, it may be possible to detect CSVD by imaging the eye, specifically the retina. The retina and brain share similar anatomic and physiologic features, and retinal changes can be easily detected. Our research aims to a novel imaging technique which will detect precise changes in capillary function by tracking high-order hemodynamics in retinal capillaries. To achieve this, we will develop a new high-speed wide-field adaptive optics near-confocal ophthalmoscope (AONCO) with a green light capable of precisely assessing higher-order flow dynamics in retinal capillaries to detect and monitor CSVD. Our research has three aims. In Aim 1, we will develop a new high-speed wide-field AONCO, which is capable of precisely assessing higher-order flow dynamics in retinal vessels of various sizes, from the largest arterioles to the smallest capillaries. In Aim 2, we will demonstrate AONCO-measured retinal capillary pulsatile hemodynamics as a sensitive biomarker of CSVD. In Aim 3, we will develop a novel machine learning (ML) approach for fully automatic analysis of flow dynamics in retinal vessels using AONCO and compare the ML measurements to conventional measurements. Our research has the potential to offer groundbreaking insights into microcirculation at the capillary level, providing crucial information about the vascular health of the central nervous system. This is particularly important given the prevalence of small vessel abnormalities and their impact on microvascular health, with significant implications for our understanding of CSVD.

NIH Research Projects · FY 2025 · 2024-09

Abstract Hidradenitis suppurativa (HS) is a common, debilitating inflammatory disease characterized by unique pathological features that includes epithelialized tunnel formation. Chronically draining, intradermal tunnels are unique feature of HS pathology and contribute to robust inflammation significantly affecting patients’ quality of life. Tragically, no consistently effective treatments exist for HS tunnels. In addition, the progress in the field is hampered by the lack of clinically relevant HS models. We assembled a multidisciplinary collaborative team with unique and complementary expertise in HS, 3D skin models, glucocorticoid synthesis and signaling. The team generated preliminary data obtained from patients’ tissue specimens: samples from HS tunnel, lesional skin above the tunnel, along with the age, gender, and location-matched healthy skin controls and found that cortisol and steroid synthesis pathways are markedly suppressed in HS tunnels, leading to perpetual pro- inflammatory keratinocyte activation. We also found lack of glucocorticoid receptor (GR) activation in HS tunnels, which was supported by HS transcriptomics signature characterized by marked downregulation of cortisol synthesis and GR signaling, again uniquely associated with the tunnels and not observed in lesional keratinocytes. Importantly, we successfully developed the first 3D organotypic model from primary HS tunnel keratinocytes and fibroblast that recapitulates tunnels structure in patients. Based on the robust preliminary and published data, we propose a novel concept of HS tunnel as an intradermal perpetual cellular activation process, in which its deregulation, in particular lack of cortisol synthesis, is a major contributor to pathophysiology. Further, we hypothesize that inhibition of epidermal and dermal cortisol production coupled with dysfunctional cellular activation play a central role in HS tunnel pathogenesis. To test this, we outlined three Aims which will utilize a) tissue and b) primary cell obtained from HS patients in distinct locations: HS tunnels, skin above the tunnel, perilesional skin (all from the same patient) and location, age, sex, ethnicity matched controls; c) organotypic 3D HS tissue generated from these primary cells. HS tissue, cells and organotypic cultures will be maintained under normoxia and hypoxic conditions and challenged by insult and Aim 1 will determine the role of cortisol synthesis in HS tunnels and 3D organoids by using spatial transcriptomics and measuring cortisol production, whereas the other two Aims will offer mechanistic insights that can reveal potential new therapeutic avenues. Aim 2 will test if targeting cortisol synthesis can restore the function of tunnel keratinocytes and fibroblasts and their activation, whereas Aim 3 will focus on how genomic and non-genomic GR signaling contributes to pathophysiology of HS tunnels and HS in general. Better understanding the mechanisms through which cortisol synthesis and GR signaling modulate tunnel biology and inflammatory response in HS will offer mechanistic insights regarding HS pathophysiology and may lead to novel tunnel-targeted therapeutics to modulate cortisol synthesis in HS and ameliorate disease progression.

NIH Research Projects · FY 2025 · 2024-09

PROJECT SUMMARY The severity of traumatic injuries has increased in recent years, resulting in further complications that can impair patient recovery or even result in death. The rate of injuries that become chronic wounds has also increased in recent years. In both the acute and chronic injury site, there are key regulators of inflammation needed to protect the body from pathogens, remove damaged tissue, and recruit new vessels to supply nutrients to tissues undergoing repair. Failure to balance these beneficial hallmarks of inflammation with a transition to tissue regeneration has resulted in secondary tissue damage and chronic injury progression. Immune cells, such as macrophages, remodel the extracellular matrix and release cytokines to govern the injury microenvironment, but dysregulation of these processes can result in chronic inflammation and non-healing wound formation. Locally occurring or exogenously delivered chondroitin sulfate (CS) is a potent regulator of inflammatory cytokine signaling and can help restore balance in dysregulated inflammatory conditions. Moreover, CS can directly modulate immune cells towards anti-inflammatory phenotypes. However, uncontrolled CS delivery can impede tissue repair by creating a physical barrier to local cells. Establishing a balance between modulating inflammation and promoting repair with CS will require investigation of the specific role of CS-presentation on the local immune response. To that end, the goal of this project is to engineer CS biomaterials that control CS presentation in the injured tissue and reprogram inflammatory immune states to support resolution of chronic inflammation and promotion of tissue repair. Over the next 5 years, we will investigate the use of nanoscale and microscale CS biomaterials to resolve excess inflammatory cytokine activity and reprogram immune phenotypes towards an anti-inflammatory, pro-regenerative state. These materials will be evaluated through in vitro studies to identify intrinsic and extrinsic molecular mechanisms by which CS-presentation reprograms immune cells. Translational mouse mouses will be used to investigate CS-presentation in tissue localized inflammation as an acute strategy to modulate chronic disease progression as a prophylactic strategy, and as a chronic strategy to treat chronic inflammation. Two distinct injury models that experience chronic inflammation through immune dysregulation will be utilized. The first model that will be employed is a rodent model of spinal cord injury, as there is no cure for paralysis associated with the injury, in part due to the robust inflammation that results in secondary injury and progresses into a chronic diseased state. The second model used will be a rodent skin injury model, as the acute injury can be used to test therapeutic outcomes that can subsequently be evaluated in chronic, non-healing skin wounds. Development of strategies for chronic, non-healing wounds is essential as there is no unifying treatment strategy, and of the therapies that exist, tissue repair is inconsistent across patients. Use of two disparate injury models will lead to an improved understanding of the role of CS on the local immune cells responsible for healing and will enable CS therapies that can re-establish immune balance without impairing tissue repair.

NIH Research Projects · FY 2025 · 2024-09

Ulcerative colitis (UC) is a chronic and devastating immune-mediated disease. Despite growing evidence of the importance of diet in UC, few clinical trials have examined the impact of diet on inflammation–especially among Americans. The long-term goal of our team is to develop evidence-based, personalized dietary treatments for UC that consider individual patient factors, including tailored food preferences, to improve both disease inflammation and adherence. From our pilot data, we have evidence that a prudent low-fat/higher diet—even with American food staples—may help to decrease disease inflammation compared to Western diets and that stool microbiome signatures may guide future flares. We also have pilot data from my K23 cohort suggesting that patients with UC carry polyunsaturated fatty acids (PUFA) pathway genetic variants in enzymes that alter the imbalance of n-6 to n-3 PUFA ratios in the blood and tissues. These levels in prior studies have been associated with UC risk. The overall objectives of this study are then to test the effect of an American-tailored low-fat (<3:1 ratio of n-6 to n-3), high fiber diet on disease remission in American patients with mild to moderate UC. We will also test whether baseline individual factors, such as the stool microbiome composition and circulating blood levels of PUFAs, impact diet-mediated inflammation. The central hypothesis is that patients will have a greater likelihood of achieving disease remission by week 8 on the American-tailored low-fat/high-fiber diet than when on their usual diet. Further, individual factors such as stool microbiome composition and PUFA blood levels will predict response to diet therapy. The central hypothesis will be tested by pursuing three specific aims: 1) Determine the effect of an American-tailored anti-inflammatory diet on UC inflammation; 2) Identify the microbiota composition and functional metabolites that mediate the relationship between diet and UC inflammation; and 3) To define the role of PUFA metabolism in modulating intestinal inflammation in UC. Under the first aim, we will evaluate the efficacy of an American-tailored, high fiber and low-fat diet using a cross-over design on 122 patients with mild to moderate UC. Our primary outcome will be clinical and biochemical remission using the validated simple clinical colitis index (SCCAI) and Fecal Calprotectin (FC) at week 8. Patients will receive catered meals for the diet intervention and stipends for groceries when on the placebo diet. Under the second aim, we will examine microbiota abundance and microbiota-derived metabolites at baseline and those associated with changes occurring from the diet intervention and among responders/non-responders to the diet. The third aim examines the influence of PUFA metabolism (including PUFA serum levels) as predictors of disease inflammation and response to diet. The proposed research is significant because we are developing an evidence-based anti-inflammatory diet for UC tested in a controlled clinical trial that also considers local, affordable foods for Americans, which is unprecedented in prior studies. Our research is innovative because it is the first attempt to tailor dietary therapy in UC that examines individualized predictors of response to diet.

NIH Research Projects · FY 2025 · 2024-09

Project Summary Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of cancer deaths with a 5-year survival rate of 12%. Over 90% of PDAC is driven by oncogenic KRAS, however inhibitors targeting KRAS have been unsuccessful in the clinic thus far. Targeting oncogenic vulnerabilities is a key alternative approach. Oncogenic RAS-generated reactive oxygen species (ROS) drives tumor progression through hyperactivation of proliferative, anti-apoptotic, and metastatic pathways. However, ROS can also trigger tumor suppressive outcomes through cellular damage. The nucleotide pool-cleansing 8-oxo-dGTPase MutT Homolog 1 (MTH1) is a critical redox protective adaptation in RAS-driven tumor cells to overcome tumor-inhibitory ROS mediated consequences. MTH1 has been shown to prevent oncogene-induced oxidative stress and damage, and maintain high KRAS oncoprotein expression, associated ROS-driven oncogenic signaling, and tumorigenicity in lung cancer. Given the importance of MTH1 in KRAS oncogenic biology and the fact that over 90% of PDAC is driven by oncogenic KRAS, I propose that MTH1 is similarly important in PDAC. In support of this idea, TCGA analysis revealed MTH1 expression is significantly higher in tumor tissue compared to normal tissue, and high MTH1 significantly correlates with poor disease-free survival. The Rai lab reported 8-oxodGTPase activity is significantly elevated in patient PDAC tumor vs. normal tissue. Preliminary data show MTH1 loss reduces tumor burden in a subset of PKT cohorts, with lower burden associated with both reduced intratumoral EGFR expression and in cytokines associated with an immunosuppressive tumor microenvironment (TME). When MTH1 is depleted via shRNA in PDAC cell lines, there is a significant decrease in proliferation associated with decreased total EGFR. Analysis of human PDAC tumor data through TIMER 2.0 shows intratumoral MTH1 expression significantly correlates with infiltration of myeloid derived suppressor cells (MDSCs), suggesting high MTH1 expression supports and/or creates the immunosuppressive TME that make PDAC so difficult to treat. Therefor I hypothesize MTH1 is important for PDAC tumorigenesis through both tumor cell-intrinsic as well as previously-unappreciated extrinsic mechanisms. To test this hypothesis, I will use our novel PKT mouse models with systemic and pancreas-specific MTH1 loss. Experiments proposed in Aim 1 will assess how systemic vs pancreas-specific MTH1 loss affects in vivo KRAS tumorigenesis; Aim 2 will independently ascertain how MTH1 regulates KRAS- driven transformation and PDAC chemoresistance. Upon completion of these studies, we will establish novel mechanisms by which MTH1 regulates tumorigenesis thus filling a gap in the field regarding the link between MTH1 and KRAS in PDAC. Lastly, these aims have the potential to validate MTH1 as an alternative to targeting oncogenic KRAS in PDAC patients which has been unsuccessful to date.

NIH Research Projects · FY 2025 · 2024-09

Abstract/Project Summary For this project, we propose a type 3 hybrid implementation-effectiveness randomized controlled trial (RCT) comparing two strategies that engage the social networks of current PrEP clients from communities with high HIV incidence to extend the reach of HIV self-testing (HIVST) and PrEP. We aim to evaluate the effectiveness, resource needs (including cost) and implementation factors of Test-to-PrEP, a strategy in which current PrEP clients directly distribute HIV self-tests (HIVST) and PrEP resources to their social network contacts, and a comparison social network referral strategy without direct distribution of HIVST. Building on successful pilot testing of the Test-to-PrEP strategy through two Ending the HIV Epidemic (EHE) Supplement Projects, our team, supported by the Florida Department of Health, community partners Prevention305, and the Implementation Science Coordination, Consultation, and Collaboration Initiative (ISC3I), seeks to conduct this trial in Miami-Dade County, Florida—a region with a one of the highest rates of new HIV diagnoses in the United States and an EHE priority areas. The trial encompasses two key components: (1) strategically located sites in priority neighborhoods for HIV prevention, ensuring diverse representation of Latino and Black PrEP client participants, and (2) the use of social networks for disseminating HIVST and PrEP information. Participants (N=320 PrEP client egos) will be recruited at clinic sites, with randomization by clinic block to one of the two social network strategies being evaluated. Utilizing the Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework and the Consolidated Framework for Implementation Research (CFIR), the study will assess the reach and implementation of each strategy and identify contextual factors associated with success including cost and resource requirements. Effectiveness will be evaluated based on completion of HIVST among social network alters, changes in PrEP knowledge, and PrEP or HIV treatment initiation. Both strategies aim to overcome structural and socio-cultural barriers by using trusted networks, specifically engaging PrEP clients to provide social network support and resources for accessing PrEP/HIV treatment. Understanding the effectiveness and resource requirements of these two strategies will inform their adoption in other EHE priority areas, contributing significantly to the broader efforts to combat the HIV epidemic.

NIH Research Projects · FY 2025 · 2024-09

ABSTRACT Because of the increase in life expectancy, a larger fraction of the population is now elderly and afflicted by age- related diseases with a huge cost for the health care system. Understanding the process of aging is thus imperative to help with the identification of strategies for healthier and more graceful aging. Exciting new studies in the pioneering organism C. elegans show that glia, a previously unsuspected cell type, communicate long distance to other cells to control stress response and aging. Furthermore, gene expression analysis in mice and humans show that glial genes undergo larger changes in expression, as compared to neuronal genes, during aging. Taken together, these data support the idea that glia may govern aging across species. However, the understanding of the function of glia in aging is in its infancy. Our lab has dedicated the past 17 years to the study of glia in C. elegans and thus is perfectly positioned to significantly contribute to this exciting new area of research. In our studies, we have identified the Cl-/HCO3- permeable channel clh-1 as a major contributor of ionic homeostasis in the worm nervous system. We have published that clh-1, by controlling Cl- and HCO3-, regulates pH and GABA signaling in the nervous system. We have now unexpectedly discovered that knockout of clh-1 extends lifespan and increases stress resistance. Our preliminary data support that the stress response transcription factor daf-16/FOXO is needed for clh-1 mediated changes in lifespan. In this exploratory application, we will leverage the power of C. elegans genetics and the imaging and solutes supplementation methods we have developed in the last 17 years to begin deciphering how the glial ion channel clh-1 controls organismal aging. Our specific aims are: 1. To establish what function of glial clh-1 influences aging, and 2. To identify tissues and pathways regulated by glial clh-1 in aging. This work will lay the foundation for future studies on the role of glial clh-1 and glia in general in aging and stress response. Ultimately, our work will advance our understanding of the role of glia in organismal aging, potentially suggest novel targets for the treatment of age- related disease, and even help identify strategies to improve our quality of life in old age.

NIH Research Projects · FY 2024 · 2024-09

PROJECT SUMMARY/ABSTRACT The pain of loss figures prominently for millions of Americans, and while the emotional toll of bereavement is well-recognized, resulting disruptions to social connection often go unnoticed and unaddressed. The proposed study examines ruptures to social connection following what is widely acknowledged as the most devastating form of loss: the death of a child. Bereaved parents face increased risk for numerous adverse health outcomes including cardiovascular disease, dementia, and early mortality. One likely contributor to these outcomes is social isolation. For many parents, their child’s death precipitates long-term estrangements. Friends and family often do not know what to say or do and may avoid contact. Drained by the need to constantly “put on a brave face,” parents may self-isolate, and even close relationships may deteriorate or collapse. Social isolation itself is a well-established risk factor for physical and mental illness, and its adverse outcomes mirror those of parental grief. Healthcare systems are in a unique position to address bereavement-induced social isolation due to their many touchpoints with families. That said, direct clinical care for every bereaved parent is neither possible due to finite resources, nor called for depending on individuals’ risk levels and preferences. Both the public health model and the transitional model of bereavement care call for the majority of bereaved individuals to be supported over the long term by their surrounding communities. However, bereaved parents often face breakdowns in social relationships at the very time that they need these informal supports most. It is therefore critical that healthcare systems have interventions and resources to help bereaved parents build and maintain community-based social support. As a basis for these interventions, research identifying specific intervention targets is sorely needed. While qualitative studies have described the numerous social challenges faced by bereaved parents, existing research stops short of quantifying changes in specific social network characteristics and their impacts on perceived isolation (i.e., loneliness), or offering adaptive strategies to help maintain social connection. The proposed mixed methods study seeks to fill this gap by 1) quantifying changes in social network characteristics (negative interactions, social integration, emotional support, shared sense of purpose, network size, network composition); 2) determining associations among network characteristics, perceived isolation, and health; and 3) identifying adaptive strategies that help maintain social connections. We will conduct a quantitative survey of approximately 300 bereaved parents assessing network characteristics, perceived isolation, and health, and in-depth, semi-structured interviews with a subset of ~45 parents to identify strategies that help maintain social connection. The long-term goal of this research is to develop a multimodal intervention that can be implemented by healthcare systems to help mitigate bereavement-induced social isolation. The proposed study has the potential to reduce isolation and adverse health outcomes among the millions of bereaved parents in the U.S., and potentially can be expanded to other bereaved populations.

NIH Research Projects · FY 2025 · 2024-08

PROJECT SUMMARY Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy projected to be the 2nd leading cause of cancer-related deaths in the United States by 2030, with a dismal 5-year survival of 12%. PDAC is refractory to standard chemotherapy and immunotherapy due to intrinsic and acquired resistance. Two key culprits associated with therapeutic resistance are frequent infiltration of tumors by immunosuppressive innate immune cells, particularly neutrophilic/granulocytic myeloid-derived suppressor cells (gMDSC), as well as pro- inflammatory signaling by cancer-associated fibroblasts (CAF), which dominate the non-tumor stroma and act as cellular antennae to transmit inflammatory cues that further beckon gMDSCs to the tumor microenvironment (TME). In dissecting the unifying mechanisms that underpin the relationship between these key constituents in the TME and chemoimmunotherapy resistance, our data uncover novel signaling interactions between gMDSC- derived transmembrane TNF (tmTNF) and TNFR2-expressing inflammatory CAFs in driving tumor-permissive effects. Moreover, overexpression of TNF-TNFR2 signaling in human PDAC tumor transcriptomes is associated with chemoimmunotherapy resistance across multiple datasets spanning diverse clinical settings. Building on these observations, the overall mission of this proposal is: (1) to mechanistically dissect the pathogenic signaling and spatial interactions between gMDSC-tmTNF and CAF-TNFR2 governing chemoimmunotherapy resistance in PDAC; and (2) catalyze preclinical development of a highly selective TNFR2 antagonistic antibody TY-101—which traps TNFR2 monomers and prevents assembly of signaling trimers—to disrupt gMDSC-CAF crosstalk and overcome chemoimmunotherapy resistance in preclinical models. Aim 1 will define the precise contributions of gMDSC-tmTNF and CAF-TNFR2 signaling communication and spatial interactions to chemoimmunotherapy resistance using innovative preclinical mouse knock-in/knock- out modeling (murine) and single-cell spatial methodologies (human). Aim 2 will elucidate the molecular mechanism by which gMDSC-CAF crosstalk regulates gMDSC-TNF production via cooperative MAP kinase and STAT3 signaling. Moreover, we will also determine the functional significance of this cooperative gMDSC-TNF mechanism on CAF polarization: a) in vivo using a tandem gMDSC depletion-adoptive transfer model; and b) in human patients’ peripheral blood gMDSCs from subjects enrolled in a phase 1 clinical trial investigating MEK and STAT3 inhibition in advanced PDAC. Finally, Aim 3 will determine if selective targeting of TNFR2 using TY- 101 improves sensitivity to chemoimmunotherapy by remodeling gMDSC-CAF spatial habitats and CAF plasticity to prolong survival in vivo. Together, successful completion of these aims will uncover novel insights into the tumor-permissive and tolerogenic role of myeloid-CAF crosstalk in the TME, as well as generate compelling preclinical rationale and a compendium of novel predictive biomarkers for an upcoming clinical trial combining neoadjuvant TNFR2 inhibition with chemoimmunotherapy in patients with operable PDAC at our institution.

NIH Research Projects · FY 2025 · 2024-08

Pollution levels in the USA are rising due to climate change, wildfires and increased vehicle traffic. Recent epidemiological studies indicate that air pollution is a contributing factor to AMD, glaucoma and other ocular diseases. Health risks from air pollution are mostly attributed to fine particulate matter smaller than 2.5 microns (PM2.5) that can induce oxidative stress, DNA damage and activate inflammatory pathways throughout the body. Indeed, PM2.5 levels are correlated with increased incidence of AMD, glaucoma, elevated IOP and changes to the RPE, outer segment layer, and retinal arterioles. However, the molecular changes induced by acute and chronic outdoor air pollution in the retina and the role of intrinsic protective tissue responses in reducing damaging effects of pollution are not understood. Furthermore, the molecular and cellular effects of air pollution in association with age or AMD-like risk factors has not been examined. Therefore, much remains to be defined about the underlying mechanisms of pollution-induced retinal damage and there is a clear need to generate and characterize reproducible animal models of PM2.5-induced retinal disease. This proposal addresses an understudied yet highly significant area of environmental health and ophthalmic research. A newly designed animal housing unit overcomes prior technical barriers by allowing whole-body exposure of defined PM2.5 pollutants at specific concentrations. Our overarching hypothesis is that aerosolized PM2.5 induces specific oxidative stress and inflammation pathways and alters intrinsic tissue protective responses, leading to retinal pathology in wildtype mice, and that damage is exacerbated in retinas susceptible to pollution from aging and underlying AMD-like pathology. Aim 1 will test the hypothesis that PM2.5 pollution exposure causes sustained inflammatory changes in the retina and alters intrinsic cell stress responses. We will measure aerosolized PM2.5-induced molecular and cellular changes in normal, aged and AMD-like mouse retinas over time, using flow cytometry, cytokine assays and scRNAseq. Aim 2 will test the hypothesis that PM2.5 exposure accelerates the rate and extent of retinal pathology in aged and AMD-susceptible mice. Therefore, this study will have an important impact on the field by developing new mouse models used to characterize pollution effects, define the natural history of pollution-induced retinal pathology, characterize underlying mechanisms of pollution-induced retinal damage and intrinsic tissue responses, and will identify targets for future study and therapeutic intervention.

NIH Research Projects · FY 2025 · 2024-08

REALIST WOMEN Study A Virtual Reality (VR) Interven�on for Stress, Resilience, and Blood Pressure Management in Black Women Background: Black women have a higher rate (approximately 60%) of cardiovascular disease (CVD) risk markers (e.g., hypertension) compared to their white female counterparts aged 20 and older (45.4%). Addi�onally, Black women are more likely to suffer from insufficient sleep (less than 6 hours), increasing their CVD risks. Stressors, especially complex and cumula�ve intersec�onal stressors (such as economic strain, caregiver burden, racial stress, and gender discrimina�on) experienced by Black women, are upstream determinants of hypertension and insufficient sleep. To cope with intersec�onal stress, Black women have developed unique forms of resilience. Current psychological and mental health treatments do not specifically address intersec�onal stress. Therefore, to address the intersec�onal distress experienced by Black women, we need behavioral treatments that can provide therapeu�c relief when needed. Innova�on and Approach: Realist Women Study aims to pilot test the effec�veness of a culturally tailored VR-exposure stress management program in addressing intersec�onal stress and improving cardiovascular health in Black women. This K01 study aims to conduct focus group and individual interviews with 16 Black women to develop a community-defined concept of resilience. Addi�onally, the study will assess stress, sleep health, and feedback on using virtual reality (VR) for stress management. It will also explore barriers and mi�ga�on strategies related to immersive technology usage among Black women dealing with the superwoman schema coping (SSC). The Study is a pilot randomized clinical trial with (RCT) a total of 60 par�cipants, focusing on hypertensive Black women. The hypothesis is that par�cipants in the stress management virtual reality (VR-SM) group (n=30) will experience reduced stress (a minimum 12-point reduc�on in cumula�ve intersec�onal stress scores), an increase of at least 0.77 points in CD-RISC scores, more days of sufficient sleep (at least 7), a significant decrease in blood pressure (BP), and adherence to the VR-SM program (using at least 50% of the total modules). This research seeks to address a cri�cal gap in the literature by exploring the feasibility and impact of VR- based interven�ons in this underserved popula�on. Relevance: The Study aims to reduce morbidity and mortality associated with hypertension and insufficient sleep in Black women by providing an innova�ve and accessible VR-based interven�on tailored to their unique needs. This research represents a crucial step in addressing health dispari�es and improving cardiovascular outcomes in this high-risk demographic. This K01 award will provide pilot data for an R01-level RCT to develop a VR-delivered, culturally tailored Mindfulness-Based Stress Reduc�on (MBSR) program to enhance resilience to cumula�ve intersec�onal stress and BP management for Black women. It will also further the candidate’s training in psychological trauma research and biobehavioral medicine, equipping her with new skills in prac�ce-based clinical trials, digital health interven�ons, ac�graphy, ecological momentary assessments, and advanced research design and analysis. These skills will ensure her success as an independent inves�gator focused on inves�ga�ng and addressing unique stress responses among minori�zed popula�ons while examining the effects and mechanisms of scalable digital health solu�ons for Black women experiencing elevated stress levels, poor sleep, cardiovascular health issues, and psychological resilience.

NIH Research Projects · FY 2025 · 2024-08

Project Summary Pancreatic cancer is the third leading cause of cancer-related deaths in the United States with a 5-year survival rate of 12%. Despite the success of immune-modulating therapies such as immune checkpoint blockade (ICB) in other cancers such as melanoma, single agent ICB is decidedly ineffective in pancreatic ductal adenocarcinoma (PDAC), leaving surgery and palliative chemotherapy the only options for over 80% of patients. CD8 T cells are the key effectors of anti-tumor immune responses that recognize and eliminate early malignant cells and can enforce durable responses that prevent recurrence and metastatic spread through adaptive immune memory. In PDAC, chronic exposure to cellular constituents in the tumor microenvironment (TME) leads to the terminal dysfunction of CD8 T cells, termed “exhaustion”. Exhausted CD8 T cells (TEX) have reduced proliferative capacity, an inability to persist and proliferate, and limited protective capacity compared to functional CD8 T cells which is a major barrier to the success of immunotherapy in PDAC. Stelekati et. al. has recently shown that antagonizing surface checkpoint molecules (such as PD-1) in chronic infection can synergize with overexpression of one micro-RNA (miR), miR-29a, in CD8 T cells to abrogate TEX differentiation and restore antigen-specific cytotoxicity and T cell memory In parallel, the Datta lab at UMMSM has recently uncovered TNF signaling to drive T cell dysfunction in PDAC through a myeloid TNF-TNFR2 dependent manner. The goal of this project is to determine the contribution of TNFR2-miR-29a to CD8 T cell dysfunction in PDAC to generate durable T-cell mediated antitumor activity. I hypothesize that miR-29a regulates TEX differentiation by downregulating immunosuppressive signaling and provides a promising intervention to overcome resistance to immune checkpoint blockade in PDAC. Using the canonical KPC model of PDAC engineered to express the neoantigen Ova, I retrovirally overexpress (OE) miR-29a in antigen-specific OT-1 CD8 T cells and observed improved tumor clearance, along with altered phenotypic states. Consequently, in this project I aim to: (1) alter the differentiation of terminally exhausted cells to a progenitor and memory-like phenotype that express Ly108, TCF-1, and CD127, which has shown to be the subset responsive to a-PD-1 checkpoint blockade therapy. I will then validate the translational importance of these findings by developing an effective combination strategy using miR-29a in mice; (2) determine the precise contribution of myeloid-derived TNF-TNFR2 signaling upstream of terminal TEX differentiation in the PDAC tumor microenvironment. By validating this novel mechanistic link between myeloid immunosuppression and terminal T cell exhaustion, this work may uncover tolerogenic circuitries characteristic of immunosuppressive TME’s such as PDAC. Taken together, this work will enhance our understanding of T cell dysfunction in the PDAC TME and elucidate a novel TNFR2-miR-29a axis that provides an attractive target to be further explored therapeutically in PDAC patients.

NIH Research Projects · FY 2025 · 2024-08

PROJECT SUMMARY Hispanic older adults are 1.5 times more likely to develop Alzheimer’s disease and related dementias (ADRD) compared to White older adults. Social and built environments (SBE) are social determinants of health linked to late-life cognitive function and ADRD risk. Detrimental neighborhood SBE are unevenly distributed across populations and disproportionately affect minoritized groups including US Hispanic populations. Research is growing on neighborhood SBE and ADRD among Hispanic populations, but few studies have investigated their life course neighborhood SBE and how SBE-ADRD associations differ depending on place of birth. In this study, we will use data on Hispanic participants from the Healthy Brain Initiative (HBI), a longitudinal cohort study of ≥50-year-olds without dementia from the racially/ethnically and socioeconomically diverse South Florida region. This study aims to: (1) characterize life course neighborhood SBE (e.g., access to greenspace, socioeconomic status) and how they differ between individuals born in and outside the US; (2) determine whether associations between life course neighborhood SBE exposures and late-life ADRD outcomes vary depending on place of birth (in or outside US) and percentage of life lived in the US; and (3) conduct semi-structured interviews with ~25 Hispanic older adults to develop a richer understanding of neighborhood environments and associated health behaviors and exposures experienced throughout the life course and how they differ between those born in and outside the US. Primary data collection will include administration of a questionnaire on neighborhood SBE from childhood, young adulthood, midlife and late life and semi-structured interviews of HBI participants. In ArcGIS, residential addresses will be geocoded and linked to satellite imagery and Area Deprivation Index data to characterize participants’ neighborhood socioeconomic status and greenspace access. The questionnaire and GIS data will be merged with cognitive (i.e., Cognivue global cognition score and cognitive domains such as episodic memory) and magnetic resonance imaging data (i.e., hippocampal and white matter hyperintensity volume and total brain volume in AD regions of interest). We hypothesize that life course neighborhood SBE exposures and their associations with ADRD outcomes will vary by place of birth and percentage of life lived in the US, and through the semi-structured interviews, we will develop possible explanations for any observed differences that can be tested in subsequent studies. Our study will contribute significantly to the nascent body of research on the impact of acculturation and neighborhood SBE on ADRD risk among Hispanic populations. Study findings will be used to inform novel instrument development on important neighborhood SBE for immigrant and Hispanic populations and key neighborhood SBE features to measure in future grant funded studies on Hispanic ADRD disparities to ultimately inform community-level interventions for these populations.

NIH Research Projects · FY 2025 · 2024-07

ABSTRACT KRAS and EGFR mutations are the most prevalent genetic alterations detected in human lung adenocarcinomas, and play essential roles in malignant transformation and disease progression. The small GTPase Rac1, a member of the Rho family, is a key signaling effector of KRAS and EGFR oncogenic pathways. Rac1 has been widely implicated in the formation of actin-rich protrusive structures required for cancer cell motility and invasion, as well as in the activation of oncogenic and metastatic gene expression networks. Activation of Rac1 (i.e. GTP loading) is mediated by Rac-GEFs, a large family of Guanine nucleotide Exchange Factors largely associated with tumorigenesis and invasiveness. Strikingly, there is limited information on the contribution of Rac-GEFs to lung cancer progression. Moreover, their relationship to specific lung cancer oncogenic mutations remains unknown. We carried out a systematic and unbiased screening for Rac-GEFs responsible for driving pro-motile phenotypes in KRAS mutant NSCLC cell lines. This analysis unambiguously identified three Rac-GEFs (ARHGEF39, FARP1 and TIAM2) as mediators of ruffle formation and motility in NSCLC cells. To our surprise, well-studied GEFs, such as TIAM1, TRIO, VAV isoforms and P-REX isoforms, were either poorly expressed or dispensable in our model. We therefore hypothesize that these Rac-GEFs are major players in lung cancer progression. In Aim 1, we will generate KRAS mutant cell lines deficient in RacGEFs using a CRISPR/Cas9 approach, and determine their contribution to invasion, ECM protease production and metastasis in mouse models. In addition, the requirement of selected Rac-GEFs to the development of autochthonously-arising metastatic lung cancer will be determined using a lentiviral CRISPR-based gene editing approach in Kras G12D/WT; p53 flox/flox mice (KP mice). In Aim 2 the goal is to identify and characterize Rac-GEFs as EGFR effectors in NSCLC. To unequivocally elucidate their permissive roles in mutant EGFR lung cancer progression phenotypes, in vivo lentiviral CRISPR-based Rac-GEF gene editing in an EGFR L858R-driven, p53 deficient lung adenocarcinoma mouse model will be performed. Mechanistically, we aim to disentangle the basis of Rac-GEF activation by pursuing a comprehensive signaling analysis of proximal EGFR adaptors and effectors. In Aim 3, we will first elucidate Rac-GEF-dependent gene transcriptomes and network signatures driven by mutant KRAS and mutant EGFR. Finally, we will determine Rac-GEF expression in single tumor cells isolated from malignant pleural effusions (a site of lung metastatic dissemination), as well as in single and clustered circulating tumor cells (CTCs) from peripheral blood of mutant KRAS and mutant EGFR lung adenocarcinoma patients. The identification of novel Rac-GEFs provides unprecedented information to predict metastatic disease outcome in lung cancer patients and increase the likelihood of identifying metastasis biomarkers, ultimately aiding in refining patient prognosis and decision-making in a clinical setting.

NIH Research Projects · FY 2025 · 2024-07

Aging and HIV are characterized by systemic chronic inflammation (inflammaging) and chronic immune activation (IA), both associated with cell senescence, functional impairment of immune cells and reduced immunity to infections and vaccines. Aging and HIV are also associated with metabolic changes such as decreased insulin sensitivity, dysregulated nutrient uptake and dysfunctional mitochondria. As a consequence of these changes, metabolites involved in glucose and fatty acid metabolism are released in blood. Some of these metabolites have been shown to be positively associated with inflammaging and therefore expected to be also associated with dysfunctional immunity. In people living with HIV (PWH) metabolic abnormalities have been related to virus-induced irreversible tissue damage in viremic individuals, as well as to anti-retroviral therapy (ART)-induced effects in virally suppressed individuals. Immune cells need to undergo metabolic reprogramming to meet the demands associated with immune responses, and rely on anaerobic glycolysis and oxidative phosphorylation to do so. The effects of aging in PWH on these pathways and on the metabolic mechanisms involved in the regulation of immune cell function are largely unknown and are the primary objectives of this proposal. Our hypothesis, supported by strong preliminary results, is that aging exacerbates immune defects through a dysregulated metabolic reprogramming and this effect is even more pronounced in PWH. Our studies have demonstrated that a higher metabolic status of immune cells is associated with higher intrinsic IA and lower capacity to generate protective immunity. This proposal will use data and samples from the MACS/WIHS Combined Cohort Study (MWCCS) of PWH and age- gender- and sociodemographically matched people without HIV (PWoH). We plan to evaluate how aging influences the serum metabolic profile of PWH and how this impacts the function, phenotype and transcriptional profiles of B cells, T cells and monocytes, the major cell types participating in immune responses to infections and vaccines. The role played by gut microbial metabolism on metabolic status will also be evaluated (Aim 1); we will investigate the metabolic mechanisms as well as metabolic requirements of the immune cells (Aim 2); and we will perform experiments using senolytics and metabolic modifiers to block senescent and metabolic pathways and improve, at least in vitro, immune cell function (Aim 3). Because obesity is a condition associated with altered metabolism, experiments will use samples from lean and obese PWH of different ages, as evaluated by body composition measures such as weight, waist/hip/thigh circumference, and bioelectrical impedance analysis to assess body fat amounts and depots. Younger (<50 years) and older (>60 years) lean and obese PWoH will also be included as controls. Results obtained will allow the identification of senescent and metabolic pathways to be targeted to improve the immune function of PWH up to the levels observed in PWoH controls.