Objectives/Goals: Osteosarcoma (OS) is the most common primary bone malignancy in humans and dogs. >40% of children and >90% of dogs succumb to metastatic disease. We hypothesize MYC overexpression in metastatic canine and human OS contributes to an immunosuppressive tumor environment by driving tumor-associated macrophage influx and T lymphocyte exclusion. Methods/Study Population: To characterize the role of oncogenic MYC signaling in the canine metastatic tumor immune microenvironment (TIME), 42 archived FFPE lung metastatic canine OS samples were evaluated for MYC copy number variation (CNV), mRNA, and protein expression via ddPCR, nanostring analysis, and immunohistochemistry (IHC). Seven samples also underwent GeoMX spatial profiling to more specifically evaluate T cell and macrophage transcriptional profiles based on MYC status. To determine the role of MYC target modulation as a potential therapeutic option, canine and human OS cell lines were treated with a novel MYC inhibitor (MYCi975) and assessed for effects on survival, proliferation, and cytokine profiles. Results/Anticipated Results: We demonstrate that copy number gains are not a key driver of MYC hyperactivity in canine metastatic OS. However, stratification based on MYC protein expression demonstrates that “MYC-high” tumors are associated with downregulation of cytotoxic effector T-cell associated transcripts and upregulation of tumor-associated macrophage (TAM) and extracellular matrix remodeling transcripts. We also report that MYCi975 treatment of canine and human OS cell lines results in significant inhibition of OS cell survival and proliferation at concentrations that are pharmacologically achievable in mice. Furthermore, we demonstrate MYC inhibition by MYCi975 is associated with reduced pro-inflammatory cytokine secretion in OS cell culture models. Discussion/Significance of Impact: While MYC overactivity in metastatic canine OS may not be genomically driven, other mechanisms that lead to increased MYC protein expression are associated with transcriptomic profiles supportive of local immunosuppression. Pharmacologic targeting of MYC may serve as a strategy to bolster immunotherapeutic options in metastatic OS treatment.

Objectives/Goals: Delving into the intricate web of translational research collaborations, this study analyzed the evolving landscape of the Hispanic Alliance of Clinical and Translational Research from 2020 to 2024 using cutting-edge social network analysis (SNA). SNA is a powerful tool for visualizing, understanding, and harnessing the power of networks. Methods/Study Population: We conducted a systematic document review of all the Alliance IDeA-CTR Network Calls for Pilot Projects from 2020 to 2024 including key attributes of the investigators and collaborators (e.g., academic institution, highest degree, collaborator type). Scientific collaboration was defined as two or more researchers working together in a grant proposal for a pilot project application. Study data was recorded and tracked using an Excel spreadsheet. R-Statistical software was used to analyze and map the networks resulting from collaboration interactions comparing the 2020 Call and 2024 Call. Network statistics were performed including nodes, isolates, edges, components, density, diameter, average degree, and the size of the main component. Results/Anticipated Results: Within a vibrant network comprising over 150 investigators from local and national academic institutions, clinicians (49.3%), and basic researchers (25.4%) are predominant. Initial findings showcase a remarkable surge in interdisciplinary collaborations and affiliations over time. Preliminary findings demonstrated that the number of nodes/actors increased from 16 to 75 comparing 2020 to 2024 and the edges/relationships from 12 to 66. Notably, the number of translational research clusters surged from 4 to 18, with mentorship emerging as a critical conduit bridging diverse research clusters; 16 to 78 nodes in comparison from 2020 to 2024. More extensive collaborative clusters occurred across time with over 20 researchers collaborating. A mentor was the main actor connecting these research clusters. Discussion/Significance of Impact: This study unveils the intricacies and power of translational research dynamics, showing a palpable surge in collaboration diversity and depth. By harnessing data-driven insights, our approach catalyzes informed decision-making to amplify collaboration, diversity, and network efficacy, offering invaluable guidance for policy and practice.

Objectives/Goals: High-performing translational teams (TTs) effectively draw knowledge from empirical data to develop health solutions. However, some TTs lack rigorous data approaches, resulting in inefficiency. The ICTR data science initiative integrates team-oriented data science for more innovative and reproducible translational research. Methods/Study Population: To help TTs better leverage data science, the Institute for Clinical and Translational Research (ICTR) at the University of Wisconsin-Madison orchestrated a strategic initiative involving four main actions. • Assess needs. Determine how TTs are using data science and identify essential tools for success. • Establish partnerships. Develop strategic relationships to centralize resources and engage data scientists. Provide team science training to ensure effective integration. • Develop educational pathways. Design and implement workshops to demystify novel data science tools and upskill translational scientists. • Facilitate culture change. Identify ways that all ICTR services can help identify needs, foster educational pathways, and encourage partnerships to help TTs better leverage data science. Results/Anticipated Results: Initial assessments indicated that fewer than 25% of TTs receiving pilot awards used data science tools, and only 10% had a data scientist on their team. Data from collaboration planning sessions indicated that few TTs used data science, but all were interested in learning more. To address this deficiency, ICTR partnered with the Data Science Institute and the Section of Applied Clinical Informatics. This expertise informed resource development (e.g., a data science primer, websites) and generated workshops. Educational opportunities include tailored workshops to help TTs better curate data and create more efficient workflows, graduate course modules to improve rigor and reproducibility, and seminars illustrating translational applications of AI, visualizations, and large data integration. Discussion/Significance of Impact: The ICTR Data Science Initiative was designed to empower TTs to more effectively integrate data to power translation. As data science approaches and expertise are embedded within teams, we anticipate continued increases in interest and usage of data science tools, collaborative publications, and data rich applications for extramural funding.

Objectives/Goals: Community health workers (CHWs) are links between the community and healthcare. As primary care (PC) expands to address social drivers of health, CHWs are becoming part of PC teams, yet how the two integrate is not well understood. Using an input-mechanism-outcome (IMO) model, this research seeks to develop a model to expand CHW-PC integration efforts. Methods/Study Population: Participants were recruited from Roots Community Health Center (Roots), a CHC serving historically marginalized communities, that has successfully integrated a CHW role, Roots Health Navigators (RHNs), into PC services. The preliminary conceptual framework for this study was guided by an overarching IMO model and informed by social identity theory, team science, and the interprofessional care literature. A mixed methods study was conducted in three phases: 1) cross-sectional survey, 2) semi-structured interviews, and 3) model development. The survey identified team dynamics such as communication, trust, and shared understanding, and interviews explored how these collaborative teaming mechanisms take shape. Findings were merged into a final model of CHW-PC integration that was reviewed by Roots leaders. Results/Anticipated Results: Survey results (n  =  25) highlighted highly rated team dynamics including shared understanding and acting and feeling like a team. Qualitative findings (n  =  10) described how integration occurred through complex interactions that were community-responsive and collectively reduced burnout among the team. Joint findings noted the importance of RHNs to continuity of care, building trust, and enhancing PC team effectiveness. Findings informed the development of a model of CHW-PC integration. This expanded on the preliminary conceptual framework by highlighting the dynamic relationship between mechanisms, processes, and team emergent states, as well as providing evidence to support feedback loops between inputs, mechanisms, and outcomes with overarching influence from the contextual setting. Discussion/Significance of Impact: With a deeper understanding of the mechanisms of CHW-PC integration, findings informed the development of a model that can support other communities to replicate this approach to care and address critical patient needs. Teaming factors that sustain CHW-PC integration may be transferrable to other care teams integrating nontraditional roles.

Objectives/Goals: The objective of the Clinical and Translational Science Awards (CTSA) Program Collaborative and Innovative Acceleration (CCIA) Award Initiative is to support synergistic collaborations to develop, demonstrate, and sustainably implement innovative solutions across and beyond the CTSA Consortium. Methods/Study Population: All CCIA awards between 2016 and 2022 were reviewed and analyzed by Fiscal year, activity code, and research area using NIH analytical tools and platforms. Subject matter experts categorized each award by research topics, study populations, stage of translational science, and innovation type. The number and type of collaborating organizations were noted and major accomplishments and expected outcomes were summarized. Results/Anticipated Results: Between FY2016 and FY2022, NCATS funded 37 U01 and 18 R21 CCIA awards including >90 different public and private partnering organizations. CCIA awards spanned all stages of translation including preclinical (26%), clinical (36%), implementation (31%), and public health research (7%). Of the 55 CCIA awards, 31% focused on urgent public health needs and 25% were designed to address health disparities. Broadly, types of innovations included: Data science-related projects (18%), clinical care innovations (15%), biomarker or clinical outcome assessments (13%), digital health solutions (11%), therapeutic development (11%), therapeutic discovery (9%), education and training (7%), diagnostic tools (5%), software tools (5%), or tools for clinical research (5%). In total, >735 publications cited CCIA awards. Discussion/Significance of Impact: For >8 years, the CCIAs have brought together researchers from diverse scientific disciplines across the nation to speed the development of new health solutions with broad impact. Advancements in genomic screening, for example, have led to policy changes while new delivery approaches have improved the quality of care for underserved populations.

Objectives/Goals: An association has been found between maternal diabetes and neurodevelopmental disorders (NDDs), such as autism spectrum disorders (ASD), attention-deficit/hyperactivity disorder (ADHD), and intellectual disabilities. Our objective is to observe the effects of type 2 diabetes mellitus (T2DM) on the neurodevelopment of infants. Methods/Study Population: A prospective study was performed on thirty infants who were evaluated using four neonatal neurodevelopmental assessments. Thirteen of these infants were from mothers with T2DM and seventeen of them were from mothers without diabetes. We used the Hammersmith Neonatal Neurological Examination (HNNE), Dubowitz exam, The Capute Scales, and The General Movement Assessment (GMA) to assess the neurodevelopment of these infants. HNNE assesses posture, reflexes, tone, and movement of infants. The Dubowitz exam is used to measure tone and reflexes to get an estimated gestational age (GA) of the infant. The Capute Scales has two subsections, one measures language (receptive and expressive) and the other measures visual-motor development. Lastly, the GMA was used to observe the general movements of the infant. Results/Anticipated Results: Cochran–Mantel–Haenszel determined between-group differences. HNNE, Dubowitz, and the Capute Scales had no significant difference between groups. HNNE results: 4 T2DM below cutoff; 9 controls below cutoff. Discussion/Significance of Impact: Offspring of T2DM mothers show a risk of motor delays in infancy and later language/cognition delays. Offspring of T2DM mothers should be followed due to the risk of motor delays. Early intervention could mitigate delays. This would be the first novel use of these four tools to evaluate 1-month-olds.

Objectives/Goals: The World Trade Center (WTC) Health Program (Program) Data Group was formed to address the increasing volume and complexity of analytics requests and to improve the Program’s data management capacity. Over time, the Group’s role expanded to include comprehensive data leadership and providing data-based support for decision-making. Methods/Study Population: The Program provides medical monitoring and treatment for WTC-related conditions to those directly affected by the 9/11 attacks. These activities generate an abundance of administrative and surveillance data. The Data Group was formed to establish structures and processes that would be adaptable and efficient in leveraging these data. We created a unified workflow including a shared inbox, a standardized request form, and a request-managing tracker. We established communication channels to distribute requests efficiently. We designed a request form to balance the administrative burden on requestors with the need to gather useful information for analyses. We also developed a documentation system to extract key details from forms and incorporate other relevant data to support evaluation and record-keeping. Results/Anticipated Results: From November 2021 through the end of 2023, the Data Group processed and fulfilled 93 data requests. These requests covered a multitude of functional areas essential to the administration of a limited health benefits program. The following top five functional areas made up two-thirds of all requests: Contract Management (n = 30), Research and Quality (n = 15), Operations (n = 11), Medical Policy (n = 10), and Communications (n = 7). Leveraging data collected through our request tracker, the Group conducted annual evaluations and developed visualizations to analyze trends in these requests. The evaluations helped us identify knowledge gaps, highlight areas for improvement – across the Program and within our own processes, and continue to guide and support future Program priorities. Discussion/Significance of Impact: The creation of the Data Group and unified workflow fulfilled the Program’s increasing analytic needs, enhanced oversight of data quality and usage, and facilitated data-driven Program decision-making. Continual optimization of the group’s processes enables opportunities to identify gaps in and support a range of health care delivery initiatives.

Objectives/Goals: Youth with IBD have preventive, psychosocial, and acute care needs beyond those of peers, yet receipt of services does not match those needs. Our objectives are to assess the feasibility of (1) an individualized care plan intervention to improve perceived and measured care quality and (2) a pragmatic trial design embedded in pediatric IBD practice. Methods/Study Population: This is a pilot rollout-design randomized trial (n = 60) at a regional academic medical center. Eligible patients are 13–19 years old with IBD for at least 3 months and scheduled for a follow-up visit during the trial. Research staff recruits from one cluster at a time until goal enrollment (14–16). Enrollees are randomized 1:1 to intervention (MyIBD now) or control (MyIBD after the trial). MyIBD combines a tabular summary of individualized acute, chronic, and preventive care needs with nurse facilitator support for patients to use the information. Surveys at baseline, 6 and 12 months measure care quality (Patient Assessment of Chronic Illness Care scale, vaccines, health services) and patient self-management skills (Partners in Health scale). Implementation outcomes are collected via chart review. Results/Anticipated Results: To date, 44 subjects have been randomized. Among subjects, the mean age is 16 years; 73% have Crohn’s disease, 77% have commercial insurance, 75% receive anti-TNF therapy, and 14% live in a rural area. Mean baseline perceived care quality (PACIC scale) is 76.9 (sd 16.3; out of 100); mean baseline perceived self-management skill (PIH scale) is 78.1 (sd 13.4; out of 96). On objective care quality measures, 59% have completed the HPV vaccine series, 32% have received an additional pneumonia vaccine; in the past year 68% have had a screening for mood disorders, 20% an emergency department visit for IBD, and 18% an IBD hospitalization. To date, the IBD clinical team has achieved 100% completion (intervention subjects receive MyIBD plus nurse facilitation) and 0% contamination (control subjects inappropriately receive MyIBD). Discussion/Significance of Impact: Study results to date support the feasibility of the pragmatic, embedded trial design and indicate opportunities for improvement in care quality as perceived by patients and as measured by common preventive and acute care quality indicators. An individualized care plan supported with nurse facilitation may improve pediatric IBD care quality.

Objectives/Goals: Radiation nephropathy results in morbidity and mortality in patients receiving cancer treatment. In addition, low birth weight and low nephron number are associated with increased risk for chronic kidney disease. This study examined the development and severity of radiation-induced renal hemodynamic dysfunction in a low renal mass mouse model. Methods/Study Population: Male mice (C57Bl/6, 8–12-weeks) were used to determine a suitable radiation dose regimen. Mice were subjected to fractionated bilateral kidney irradiation with 5–6 fractions of an X-ray dose of 0, 6, 8, and 10 Gy at 24-hr intervals using a CT-image-guided irradiator. Body weight and mortality were monitored for 5 weeks in mice. In a separate set of experiments, the low renal mouse model, ROP Os/+, and their normal counterpart, ROP +/+ mice were subjected to 5 fractionated bilateral kidney irradiations at 24-hr intervals with an X-ray dose of 6 Gy. Renal blood flow was assessed from renal artery resistive index (RRI) over 5 weeks post-irradiation using an ultrasound system. Transcutaneous measurement of FITC-sinistrin clearance was used to determine glomerular filtration rate (GFR). Results/Anticipated Results: The C57Bl/6 mice that received 5–6 fractions of 8 and 10 Gy had more than 50% mortality, while 100% of the mice exposed to 5 fractions of 6 Gy survived for 5 weeks. Body weight was also significantly decreased in mice exposed to 5 or 6 fractions of 8 or 10 but not 6 Gy radiation. Nonirradiated C57Bl/6, ROP +/+, and ROP Os/+ mice had similar baseline GFR and RRI. Irradiation of 5 fractions at 6 Gy decreased GFR and increased RRI in C57Bl/6 and ROP +/+ mice. Interestingly, following 5 fractions at 6 Gy irradiation ROP Os/+ mice had 25% lower GFR than wild-type ROP +/+ mice (946.3 ± 50.3 vs. 1232.9 ± 69.3 µL/min/100g BW, p Discussion/Significance of Impact: Our study determined a suitable fractionated bilateral kidney irradiation dose regimen to evaluate radiation nephropathy. Data demonstrated that fractionated bilateral kidney irradiation leads to decreased renal hemodynamics in mice. We also demonstrated that irradiation caused greater renal hemodynamic dysfunction in low renal mass mice.

Objectives/Goals: Given the challenges that early career research scientists face, especially preparing for promotion and tenure, the decision on whether to join a research team can be fraught. We developed a novel training to support informed decision-making regarding new scientific teaming opportunities. Methods/Study Population: A team science workshop entitled “Should I join this research team” was designed for early career investigators from varied disciplinary backgrounds. Learning objectives for attendees included 1) describing the role of team science in translational research, 2) determining if teaming opportunities are a good fit, and 3) crafting thoughtful responses to requests. The training was initially delivered to 38 attendees (11 K scholars) during a virtual national meeting. We adapted this training for in-person delivery to K and T scholars at our CTSA regional partners. Instructional methods shared across virtual and in-person modalities included self-reflection, think and share activities, and scenario application. In-person delivery also included short video clips and small group discussions. Results/Anticipated Results: Multiple Likert-scale items were completed by workshop participants before and after completing the workshop to evaluate attendees’ confidence in their perceived abilities to explain strengths and limitations of team science, identify characteristics of effective science teams, evaluate a team invitation, assess costs and benefits, negotiate collaborative team invitations, etc. Preliminary data from the virtual workshop suggests that 54.6% of scholars were either not at all or only slightly confident in evaluating a teaming invitation. After the workshop, 45.5% reported being very confident, and 9.1% reported extreme confidence in evaluating a team invitation. Evaluation of the in-person training, along with a comparison of virtual and in-person learning outcomes will also be presented. Discussion/Significance of Impact: Our multimodal training is designed to equip early career investigators with the tools needed to evaluate and respond effectively to research team invitations. We believe this novel training will result in informed teaming decisions for early career research scientists.

Objectives/Goals: Team science (TS) competency is important for translational science team collaboration. However, there are few educators available to assist teams. Asynchronous learning is an effective strategy for delivering TS content. The goal of this project is to expand TS education by providing online access to our learners using online modules. Methods/Study Population: The Collaboration and Team Science (CaTS) team at the University of Cincinnati provides a robust TS education and training program. As the need for team science gains recognition, CaTS has received increased requests for services, leading to a need to broaden TS offerings. To address this demand, the CaTS team created “Team Science 101,” an online, asynchronous, series of 15 modules covering basic team science concepts. Each module consists of an educational recording lasting an average of 20 minutes, optional topic resources, pre- and post-module surveys assessing learners’ confidence and satisfaction, post-module knowledge checks, and evaluation questions. Upon completing all modules, participants receive a completion certificate. Results/Anticipated Results: TS 101 will be piloted with a group of participants who expressed interest in asynchronous TS content and will be adjusted based on the feedback received. The associated pre- and post-module survey, post-module knowledge check, and evaluation questions will be monitored to determine learning levels and improve TS 101 overall. Canvas is the educational platform that houses these modules, allowing for participant follow-up and scalable dissemination. The CaTS team plans to disseminate TS 101 nationally and internationally for anyone interested in this resource. Discussion/Significance of Impact: There is a national effort to collect and curate TS education, training, and toolkits. TS 101 will be a useful educational tool that will expand the reach of team science educators, provide the foundation for educators to explore topics more deeply by building on the module topics, and provide education to broader audiences who lack access to TS experts.

Objectives/Goals: Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system that affects 2 million people worldwide causing severe disability. This study uses the Gamt-GFP transgenic mouse line as a novel approach to track oligodendrocyte lineage cell regeneration in inflammatory demyelination for identifying potential therapies. Methods/Study Population: We previously showed that Gamt, an enzyme required for creatine synthesis, is essential for oligodendrocyte (OL) maturation and survival using the Gamt-Green Fluorescent Protein (Gamt-GFP) reporter line. In this study, we capitalize on this finding and track OL lineage cells in an experimental autoimmune encephalomyelitis (EAE) mouse model by inducing immune-mediated demyelination in the Gamt-GFP reporter line. At 7 days postimmunization (dpi), both control and EAE mice receive 4 mg/kg tamoxifen for 4 consecutive days to induce GFP expression. GFP+ cells and those also expressing OL lineage markers [Olig2 (pan-OL lineage cell marker), NG2 (OL precursor cells; OPCs), and CC1 (mature OL)] are quantitated by immunofluorescent staining of spinal cord sections collected at 28 dpi. Results/Anticipated Results: Preliminary data using immunofluorescent staining demonstrated GFP was expressed in Olig2+ cells in the inflammatory ventral white matter lesions of mice with EAE, whereas no GFP labeling was present in the control mice. Moreover, GFP+ cells also expressed NG2+. In contrast, few CC1+ cells were detected in the inflammatory lesions. The low number of dual labeled GFP+CC1+ cells in these lesions suggests OPCs under the EAE environment are unable to efficiently differentiate into mature OL. Therefore, the Gamt-GFP reporter mouse can be used to identify and track activated OL lineage cell populations (i.e., GFP+CC1) in inflammatory lesions in the EAE mouse model. Discussion/Significance of Impact: The Gamt-GFP reporter line identifies activated OL lineage cells responding to inflammatory demyelination, making it a valuable tool for testing potential therapeutics aimed at enhancing remyelination. This model helps bridge the gap between preclinical and clinical research to guide MS therapy development.

Objectives/Goals: Our study team won a Public Health Answers to Speed Tractable Results (PHASTR) contract to conduct a target trial emulation to answer “Does metformin show a reduction of severe outcomes of COVID-19 or of Long COVID in the N3C Data Enclave?” We quickly delivered an answer due to productive technical and collaboration support in the N3C. Methods/Study Population: Our analytic plan was updated based on helpful feedback from the PHASTR program. We performed a trial emulation analysis using the N3C data, comparing adult new users of metformin to controls prescribed fluvoxamine, fluticasone, ivermectin, or montelukast. The composite outcome was Long COVID or Death (LC/D) within 180 days of COVID infection. We used entropy balancing to estimate the average treatment effect with a weighted log-linear model. Productivity was enhanced by reusing code workbooks and validated codesets from related N3C projects. The team of 4 (physician, informaticist, data programmer, and statistician) and key unpaid advisors spent 10 weeks developing and analyzing the data. Results/Anticipated Results: Totally, 9,660 patients were identified for analysis. After weighting, there were 248 in the metformin and control groups. In the metformin group, 4.0% developed LC/D vs. 8.5% in the control group, with an adjusted risk ratio (aRR) of 0.47 (95% CI 0.25 to 0.89). Results were consistent across subgroups and sensitivity analyses. The PHASTR contract structure helped produce high-quality results quickly by not only providing funding but also requiring a compressed timeline for a small team to focus on the study. The most time was spent on contract execution, enclave provisioning, and too many last-minute download requests. A project final report was submitted in March and a full manuscript was submitted in September. Discussion/Significance of Impact: The analysis was productive because the environment made reuse easy and supported rich collaborations among clinicians, informaticists, epidemiologists, statisticians, and data developers. Advice from PHASTR advisors (Axel) and N3C diabetes domain team members was also key to a faster completion.

Objectives/Goals: Understanding cognitive habits and values of individuals or groups, and providing tools to apply them to collaborative, interdisciplinary endeavors to better communicate between different industries, functions, and cultures. Methods/Study Population: Using literary research to establish groupings of common core values in interpersonal communications, applying established 5 patterns of “thought languages” to scale to group communications. Accepted psychological personality inventories for individuals will overlay into cognitive values, primarily using the current big five OCEAN model. Demonstrating these values to find common goals among interdisciplinary collaborations can identify prospective members, cultural differences in industry, patient communication, and public messaging in STEM. Integrating these tools into research groups to establish more efficacious communication between teams, governing bodies, and patient communication can be sampled via pre and post research surveys of feeling understood. Results/Anticipated Results: The results of feeling understood by various parties in collaborative research would be a measure of not just effective expressed communication, but received communication. Feeling understood is a current metric of communication that is correlated with satisfaction, trust, and interdependence. All of these results are integral to the successful operations of collaborative projects. Demonstrating a positive correlation between applying the 5 thought languages and better-surveyed outcomes of understanding will guide the effectiveness of this as a future collaborative tool for translational sciences. Discussion/Significance of Impact: The significance of effective communication based on positive reception will foster future collaborations. Encouraging familiarity between differing individuals, groups, and industries, even between subjects and researchers, patients and healthcare. More satisfaction, more trust, and more interdependence will propagate between these groups.

Objectives/Goals: Primary sclerosing cholangitis (PSC) manifests with an inflammatory milieu that leads to fibrotic scarring of the liver. Human PSC liver bile ducts are enriched with neutrophils; however, their infiltration and functional role is unexplored. Our goal is to investigate the mechanism and impact of peribiliary neutrophil infiltration observed in PSC. Methods/Study Population: Primary cholangiocytes (bile duct cells) isolated from WT and mouse models of PSC (3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)-fed mice and Mdr2-/- mice) were analyzed by RNA-sequencing. Immunofluorescence (IF) was performed on liver tissues from PSC patients and mouse models of PSC for markers of bile ducts and neutrophils (KRT19 and MPO). Intrahepatic leukocytes (IHL) isolated from mice livers were evaluated for neutrophil abundance and activation state. Anti-Ly6G antibody-mediated neutrophil depletion in Mdr2-/- mice was analyzed by IF, histology, and cytometry by time-of-flight (CyTOF). Cholangiocytes stimulated with TNFα (to induce an inflammatory phenotype) were analyzed for neutrophil chemoattractants with genetic and pharmacological interventions. Results/Anticipated Results: RNA-seq analysis of primary cholangiocytes from PSC mouse models revealed enrichment in inflammatory and neutrophil degranulation pathways. Flow cytometry and RT-PCR analysis revealed an increase in the neutrophil population in PSC mice with activated phenotype. Peripheral depletion of neutrophils in Mdr2-/- mice alleviated liver injury and inflammation, along with a reduction in peribiliary neutrophil infiltration and attenuated bridging fibrosis. CyTOF analysis showed a significant reduction in CD8+ T cells upon neutrophil depletion, implying neutrophils sustain CD8+ T cells in PSC liver. Mechanistically in cholangiocytes, TNFα mediates expression of neutrophil chemoattractants, CXCL1 and CXCL8, through the cyclic GMP-AMP synthase stimulator of interferon genes (cGAS-STING) pathway. Discussion/Significance of Impact: Our findings suggest that activation of the STING pathway in cholangiocytes in cholestatic liver disease triggers an immune response resulting in peri-portal neutrophil infiltration via CXC chemokines. The sustained presence of these activated neutrophils engages the adaptive immune system to perpetuate the inflammation and fibrosis seen in PSC.

Objectives/Goals: Depression is common among people living with HIV (PLWH). This study explored the link between reduced metacognitive awareness and depression in PLWH. It utilized a positive emotion regulation task to compare brain activation during viewing versus upregulating positive emotions. Methods/Study Population: Depressed PLWH (N = 24; mean age  =  53; HAM-D mean  =  19) participated in an emotion regulation task while blood oxygen-level-dependent (BOLD) responses were recorded. In the emotional regulation task, participants were shown the International Affective Picture System (IAPS) a series of positive, negative, and neutral images. Participants were asked to view these images and given instructions to either negatively reappraise (RN) or positively reappraise (RP). In the RP condition, participants were no longer shown the image and asked to upregulate their positive emotional responses associated with it. Ten onset times were included for each trial. Results/Anticipated Results: A one-sample t-test was conducted to analyze contrasts between reappraisal of positive images and viewing positive images (RP > VP). Results showed significantly greater activation in the posterior cingulate and angular gyrus during the RP condition (peak MNI: 18, -52, 34; p < 0.001, uncorrected, k > 10 voxels). In comparing the reappraisal of negative images to viewing negative images (RN > VN), there was increased activation in the right supramarginal gyrus (peak MNI: 50, -28, 22; p < 0.001, uncorrected, k > 10 voxels). When contrasting the reappraisal of positive to negative images (RP > RN), BOLD signals were higher in the left dorsolateral prefrontal cortex (peak MNI: 40, -38, 32; p < 0.001, uncorrected, k > 10 voxels). Discussion/Significance of Impact: Findings underscore that depressed PLWH demonstrates BOLD responses in brain regions linked to appetitive motivation and meta-cognitive awareness during the RP condition which demands more executive resources among those with depression, highlighting the complexity of emotional regulation in this population.