ABSTRACT IMPACT: Brain networks can be explored by delivering brief pulses of electrical current in one area while measuring responses in other areas, and this describes an open-source novel algorithm to carry out this exploration. OBJECTIVES/GOALS: If we focus on a single brain site and observe the average effect of stimulating each of many other brain sites, visually-apparent motifs in the temporal response shape emerge from adjacent stimulation sites. There are no existing approaches to identify and quantify the spatiotemporal structure of these motifs. METHODS/STUDY POPULATION: Individual stimulation trials are correlated with one another, then a correlation-significance matrix quantifying similarity between stimulation sites is decomposed with non-negative matrix factorization, in which the inner dimension is iteratively reduced. The dimensionality reduction identifies stimulation sites that produce a common elicited temporal response, and linear kernel PCA is applied to obtain the robust profile of this response cluster. RESULTS/ANTICIPATED RESULTS: We describe and illustrate a data-driven approach to determine characteristic spatiotemporal structure in these response shapes, summarized by a set of unique ‘basis profile curves’ (BPCs). Each BPC may be mapped back to underlying anatomy in a natural way, quantifying projection strength from each stimulation site using simple metrics. Our technique is demonstrated for an array of implanted brain surface electrodes in a human patient, and our code is shared at https://purl.stanford.edu/rc201dv0636. DISCUSSION/SIGNIFICANCE OF FINDINGS: This framework enables straightforward interpretation of single-pulse brain stimulation data, and can be applied generically to explore the diverse milieu of interactions that comprise the connectome.

ABSTRACT IMPACT: We aim to understand how LTCCs impact cerebellar function. OBJECTIVES/GOALS: L-type calcium channels (LTCCs) are important in activity-dependent neurite outgrowth, which comprises neurite initiation and elongation. We used cerebellar granule neurons (CGNs) to differentiate between LTCC effects on neurite initiation vs elongation. We also tested cerebellar function in mice lacking specific LTCCs with behavioral assays. METHODS/STUDY POPULATION: CGNs were cultured from 129SvEv mouse pups at P4-P6. Potassum chloride (50mM) was used to stimulate neuronal cultures for 24 hours. Isradipine (20nM) was added to culture medium to inhibit all LTCCs for 1 hour. For Cav1.2 deletion, we crossed Cav1.2 conditional knockout mice (Cav1.2-cKO) to Syn-Cre mice (for deletion in most neurons) or Atoh1-Cre mice (for deletion in CGNs). The Cav1.2-cKO line was maintained on a 129SvEv background. For constitutive Cav1.3 deletion, mice were maintained on a C57BL/6NTac. Behavioral tasks included open field, rotarod, and Erasmus Ladder. Data were analyzed with sexes combined and separated to assess for sex as a biological variable. Studies were analyzed by one-way ANOVA, two-way ANOVA, or generalized linear mixed model, where appropriate. RESULTS/ANTICIPATED RESULTS: CGNs exhibited an increase in neurite initiation but not elongation when stimulated with potassium chloride, consistent with previous reports of activity-dependent neurite outgrowth in this cell type. LTCC inhibition with isradipine blunted KCl-induced neurite initiation. We observed no change in the length of either primary or secondary neurites with isradipine treatment with or without KCl stimulation. In our behavioral experiments, we observed no deficits in open field, rotarod, or Erasmus Ladder when Cav1.2 was deleted in most neurons (driven by Syn-Cre expression) or in cerebellar granule neurons (driven by Atoh1-Cre expression). In contrast, loss of Cav1.3 was associated with impaired motor learning in the rotarod task without evidence of ataxia on Erasmus Ladder. DISCUSSION/SIGNIFICANCE OF FINDINGS: We show a specific role for LTCCs in activity-dependent CGN neurite initiation. While loss of Cav1.2 does not affect motor learning, loss of Cav1.3 does impair motor learning. Our results help expand our understanding of LTCC function in cerebellar neurodevelopment and function.

ABSTRACT IMPACT: This research aims to identify changes in visual network function after TBI as a way to define potential therapeutic targets for neuromodulation or neural tissue substrates. OBJECTIVES/GOALS: The objectives of this study are to compare neural activity in the visual cortex following TBI with cortical activity in the uninjured brain. This study aims to characterize functional changes in single neuron activity, spike-field relationships and oscillatory activity. METHODS/STUDY POPULATION: The effects of TBI will be studied by comparing electrophysiologic recordings from Long-Evans rats with a fluid percussion injury (FPI) to rats with a sham injury. Four days after the injury or sham procedure, a laminar probe with multiple electrode contacts will be chronically implanted in the ipsilesional primary visual cortex (V1). Afterwards, rats will be anesthetized weekly for 3 weeks (up to 4 weeks post-injury) to assess visual processing in response to drifting grating visual stimulation. To assess behavioral correlates, neural activity will also be recorded while rats perform a visual discrimination task in an operant, touchscreen chamber twice weekly. Recordings will be analyzed for visually evoked units, unit entrainment to local field potentials (LFPs) and evoked oscillatory activity. RESULTS/ANTICIPATED RESULTS: Consistent with other studies, our preliminary evidence from V1 recordings in naive rats has shown that individual neurons are responsive to visual stimuli, visual stimuli are associated with evoked oscillations and unit activity is correlated with LFPs. While activity of individual V1 neurons in injured animals is expected to recover to resemble activity in uninjured animals over time, patterns of functional organization in the two groups are expected to diverge over time. We anticipate that TBI-associated axonal damage, neuronal loss and changes in synaptic weights will lead to disruptions in the timing of neural activity in V1. These perturbations of neural communication within the visual system are expected to be associated with behavioral deficits in the awake, visual discrimination task. DISCUSSION/SIGNIFICANCE OF FINDINGS: This study helps define how cortical network disruption after TBI. These changes are potential targets for novel TBI therapeutics, including neuromodulation and neural tissue transplantation. Thus, this work lays the groundwork for future studies aimed at mitigating the effects of TBI with rationally designed experimental therapeutics.

ABSTRACT IMPACT: Approximately 15% of US adults have chronic kidney disease with over 700,000 of those in the end stages where treatment options are severely limited to dialysis or kidney transplant; the research presented here will help identify novel strategies that address oxidative imbalance and preserve renal function. OBJECTIVES/GOALS: Chronic Kidney Disease patients often develop secondary cardiovascular disease - Cardiorenal Syndrome Type 4. RNA sequencing data show increased apelin receptor expression in 5/6 nephrectomy rats. The Apelinergic (APJ) system is deemed beneficial in normal physiological systems. Here we explore links between stress and the APJ system in CRS4. METHODS/STUDY POPULATION: In preliminary studies performed in NRK cells, inflammatory cytokines, IL-1β and IL-6, caused increases in apelin receptor transcripts and decreased apelin transcripts, respectfully. The literature describes inflammatory processes that contribute to degradation of many organs (kidneys, heart, and liver) suggesting an oxidative imbalance. To investigate this imbalance within CRS4, three rat cell types’’ H9c2 cardiomyocytes, HII4E hepatocytes, and NRK renal epithelial cells” will be used to assess the role of exogenous apelin on pro- and anti-oxidant levels. Cells will be pretreated with apelin or vitamin E 48 hours prior to the addition of toxins or cytokines (uremic: uric acid and d-galactose or hydrogen peroxide; cytokines: IL-1β and IL-6), to assess pro- and anti-oxidant protein levels via Western Blot. RESULTS/ANTICIPATED RESULTS: We anticipate with toxin or cytokine addition (either uremic, hydrogen peroxide, IL-1β or IL-6) in all cell types, an increase in protein levels for GPX’‘ a known measure of oxidative stress’‘ should be greater than the increases in antioxidants’‘ SOD1 and Catalase. After pre-treatment of vitamin E, GPX protein levels should decrease compared to toxin/cytokine control, while SOD1 and catalase protein levels increase; this coincides with vitamin E inducing antioxidant activity in animals and humans. The anticipated results for this study after exogenous apelin addition should reveal in all three cells types reduced levels of GPX and increased levels of SOD1 and Catalase comparable to the vitamin E treatment. DISCUSSION/SIGNIFICANCE OF FINDINGS: If addition of apelin causes an antioxidant response in all three cells types, this can build on evaluation of the APJ system as a therapeutic option for those with CKD and CRS4 to minimize both inflammatory and oxidative stress. With the data gathered here, we expect to recreate the results in a CKD rat model that highlights these same manifestations.

ABSTRACT IMPACT: Cholecystokinin-B Receptor -Mediates Growth of Hepatocellular Carcinoma with the use proglumide. Proglumide is a non-selective antagonistic drug therefore, strategies that block signaling at the CCK-BR may provide to be a novel therapeutic option for Hepatocellular Carcinoma treatment OBJECTIVES/GOALS: Cholecystokinin (CCK)and gastrin mediate the growth of Hepatocellular Carcinoma (HCC) through CCK-R and interruption of this signaling pathway could decrease HCC. CCK-Receptors are overexpressed in HCC and proliferation may be mediated through CCK-B. Blockade of the CCK-BR with proglumide decreased both growth in vitro and tumor growth in vivo. METHODS/STUDY POPULATION: RNA was extracted from murine Hepa1-6, RIL-175 and human HepG2 cells and was evaluated by qRT-PCR for expression of CCK-AR, CCK-BR and gastrin. CCK-R protein expression was analyzed by flow cytometry. HCC cells were treated in vitro with CCK peptide, the CCK-AR antagonist or the CCK-BR antagonist. Proliferation of selective CCK-R KO cells was compared to that of wild-type cells. To determine the effect of a CCK-R antagonist on tumor growth in vivo two cohorts of mice bearing subcutaneous Hepa1-6 or RIL-175 HCC tumors were treated with an oral bioavailable CCK-R antagonist proglumide or untreated water for 3-4 weeks. The mice bearing Hepa1-6 tumors were placed on a high-fat diet to raise blood CCK levels. Mice bearing RIL-175 tumors were fed standard chow to determine if proglumide could block autocrine growth by gastrin. RESULTS/ANTICIPATED RESULTS: The mRNA expression of CCK-AR, CCK-BR and gastrin were increased 80-90-fold in all HCC cell lines compared to that of normal liver. CCK-BRs were detected on >85% of the cells by flow cytometry. CCK peptide (1nM) stimulated HCC growth in vitro in both wild-type cells and in CCK-AR KO cells but not in CCK-BR KO cells. CCK-BR antagonist blocked CCK-stimulated growth in vitro but the CCK-AR antagonist did not, suggesting that the CCK-BR was responsible for mediating proliferation. In vivo tumor growth was significantly reduced with proglumide treatment by 70% (p<0.05) in Hepa1-6 and by 73% (p<0.001) in RIL-75 tumors, respectively. DISCUSSION/SIGNIFICANCE OF FINDINGS: CCK-Rs are overexpressed in HCC and proliferation appears to be mediated through the CCK-BR. Downregulation with CRISPR Cas9 or blockade of the CCK-BR with an antagonist decreases growth in vitro and proglumide therapy decreases tumor growth in vivo. Strategies that block signaling at the CCK-BR maybe a novel therapeutic option for HCC treatment.

ABSTRACT IMPACT: This work may lead to new treatments for crystalline nephropathies. OBJECTIVES/GOALS: This study investigated obeticholic acid (OCALIVA ®) as a potential treatment for 2,8-dihydroxyadenine (2,8-DHA) nephropathy using a mouse model. The treatment was investigated in both sexes at two timepoints. METHODS/STUDY POPULATION: Male and female C57BL/6J mice (12 weeks of age) were fed chow (Research Diets D19120401i) or chow admixed with adenine (0.2% w/w) ad lib for either 3.5 or 7 weeks. Mice were treated with either vehicle (corn oil) or obeticholic acid (10 mg/kg BW) by gavage 5 days per week. Each of the 16 combinations of sex/diet/timepoint/treatment groups had an n = 6 (96 mice in total). Food and body weights were measured twice per week, and 24-hour urines were collected prior to euthanasia. Serum and organs were collected and processed for biochemical and histopathological analyses. RESULTS/ANTICIPATED RESULTS: At both the 3.5-week and 7-week timepoints, dietary adenine robustly increased BUN and serum creatinine compared to control diet in vehicle-treated male and female mice (P < .01, all comparisons). At the 3.5-week timepoint, obeticholic acid reduced BUN in male (P < .05) but not female adenine mice. Obeticholic acid did not affect serum creatinine at this timepoint. At the 7-week timepoint, obeticholic acid reduced BUN in female (P < .05) but not male adenine mice. At the 7-week timepoint, obeticholic acid reduced serum creatinine in both male (P < .05) and female (P < .01) mice. Biochemical and histopathological analyses are ongoing, and we anticipate that the results will agree with the serum chemistries. DISCUSSION/SIGNIFICANCE OF FINDINGS: Obeticholic acid is FDA-approved for primary biliary cholangitis, and it is in clinical trials for several other hepatobiliary diseases. Although currently untested in humans, it is nephroprotective in many preclinical models of kidney disease. This study is the first to investigate obeticholic acid in a model of crystalline nephropathy.

ABSTRACT IMPACT: Reducing methionine levels has repeatedly been shown to reduce cancer growth in vivo, while at the same time increasing lifespan in healthy animals. However, the mechanisms behind the beneficial effects of methionine restriction are currently unknown. OBJECTIVES/GOALS: We hypothesized that comparing the response of a cancer cell line to depletion of the amino acids methionine and cysteine would give us insight into the critical role of these two closely related amino acids in cancer, and help advance methionine restriction on the translational science spectrum. METHODS/STUDY POPULATION: We used the human melanoma cell line A101D to analyze the response to three conditions: methionine depletion, methionine replacement with homocysteine, and cysteine depletion in vitro. We measured proliferation/viability, gene expression patterns, and glutathione levels. We also assessed ferroptotic versus apoptotic cell death. We then used a normal human fibroblast cell line to compare responses. RESULTS/ANTICIPATED RESULTS: The transcription factors ATF4 and NRF2 were activated by all three tested conditions in melanoma cells. Glutathione levels were decreased by ˜40% in cells grown without methionine, and by 95% in cells grown without cysteine. Lipid peroxidation was increased in cells grown without cysteine, but not in cells grown without methionine. Inhibiting ferroptotic cell death partially rescued proliferation in cysteine-depleted but not in methionine-depleted cells. Almost 70% of cells grown in methionine-depleted media stained positive for Annexin V, an indicator of apoptosis, compared to only 20% of cells grown in cysteine-depleted media. In normal cells, ferrostatin recued proliferation/viability to 86% of control levels in cysteine-depleted cells. Ferrostatin did not affect methionine-depleted normal cells. DISCUSSION/SIGNIFICANCE OF FINDINGS: These results indicate that methionine depletion leads to apoptosis, while cysteine depletion leads to ferroptosis. We found overlapping pathways activated by methionine and cysteine depletion at the gene expression levels, but divergences in cell death pathways ultimately activated.

ABSTRACT IMPACT: Small molecule readthrough compounds are a promising therapeutic with the potential to overcome nonsense mutations thereby enabling the production of functional ATM protein in patients with Ataxia Telangiectasia OBJECTIVES/GOALS: To generate a novel mouse model of Ataxia-Telangiectasia for testing small molecule readthrough compounds that both expresses a clinically relevant nonsense mutation and recapitulates the major symptoms of the disease, including a progressive loss of motor coordination not previously observed in prior A-T animal models. METHODS/STUDY POPULATION: Using a double-hit strategy to increase genotoxic stress, we generated a novel A-T mouse model that expresses a clinically relevant (c.103C>T) mutation in the Atm gene and a knockout of the functionally related Aptx gene. We then characterized the mouse across multiple domains related to the various symptoms related to the disease. This includes examination of survivability, immunologic function, cancer prevalence, and motor behavior and its associated cerebellar dysfunction and atrophy. Lastly, we tested the ability of small molecule readthrough compounds to enable production of ATM from tissue explants extracted from these ATM deficient mice. RESULTS/ANTICIPATED RESULTS: The double mutant mice display reduced survivability compared to control mice (53% vs. 97%; p<0.0001), dying at a clinically relevant rate of about 30% from thymomas. At postnatal day 400 (P400), only AtmR35X/R35X; Aptx-/- mice, and none of the controls expressing at least one wildtype Atm or Aptx gene develop a motor behavioral deficits that are associate with reduced Purkinje neuron diameter (8.0 ±0.4 µm vs. 9.92 ±0.5; p<0.01) and density (4.3 ±0.2 vs. 6.0 ±0.3 per 100 µm; p<0.05) as well as cerebellar atrophy (cerebellum/forebrain area 0.26 ±0.01 vs. 0.31 ±0.01; p<0.001). ATM deficient mice also display disrupted thymocyte development and metabolic function. When exposed to small molecular readthrough compounds, greater than 50% of the ATM protein is restored. DISCUSSION/SIGNIFICANCE OF FINDINGS: We have created a novel, clinically relevant A-T mouse model that develops a severe ataxia associated with changes in cerebellar function and atrophy as well as demonstrate the potential of SMRT compounds as an A-T therapeutic.

ABSTRACT IMPACT: My work focuses on understanding the role of an immunomodulatory pathway in Alzheimer’s disease as a potential therapeutic target. OBJECTIVES/GOALS: My long-term goal is to develop effective drugs to halt the progression of Alzheimer’s disease (AD). The overall objective of this translational work is to study the deregulation of the Lanthionine Synthetase C-like 2 (LANCL2) immunomodulatory pathway in AD. I hypothesize that stimulation of the LANCL2 pathway will inhibit progression of AD. METHODS/STUDY POPULATION: These studies use a transgenic rat model of AD, and a LANCL2-binding drug, BT-11, that crosses the BBB. Tg-AD Fisher 344 rats express human APP with the Swedish mutation and human presenilin-1 with the ? exon 9 mutation. Tg-AD rats develop age-dependent AD-like pathology. Rodent chow containing BT-11 (10mg/Kg bw) was administered orally from 5 months of age (pre-pathology) to 11 months of age. Eight groups of rats (8 rats/group) were included: WT and Tg-AD x 2 sexes x 2 conditions (BT-11 treated and untreated). Rats are analyzed for: (1) Spatial learning and memory with an active place avoidance test. (2) AD pathology including amyloid plaques and activated microglia, with hippocampal immunohistochemistry. (3) LANCL2-signaling and other AD relevant pathways, with hippocampaI western blot and RNAseq analyses. RESULTS/ANTICIPATED RESULTS: I predict that BT-11 will prevent and/or mitigate some aspects of AD pathology displayed by the AD transgenic rats (Tg-AD). Tg-AD rats treated with BT-11 should perform better in the spatial learning and memory tasks, than the untreated Tg-AD rats. I also expect that the immunohistochemical analysis will reveal reduced pathological hallmarks, including amyloid plaques and reactive microglia, in hippocampal tissue of BT-11 treated versus untreated Tg-AD rats. Through western blot and RNAseq analyses, I will establish how BT-11 treatment affects the LANCL2 signaling cascade as well as other AD relevant pathways, in treated and untreated rats from both sexes and both genotypes. DISCUSSION/SIGNIFICANCE OF FINDINGS: My proposed translational research will address the potential of targeting the LANCL2 pathway to improve AD treatment. Discovering the effects of stimulating the LANCL2 pathway on AD pathology is a novel approach in AD drug development. I expect that my studies with BT-11 will positively influence therapeutic outcomes of this devastating condition.

ABSTRACT IMPACT: This study has uncovered a novel surprising mechanism involving the epithelial adherens junctions and transposon regulation that can deepen our understanding of tumorigenesis. OBJECTIVES/GOALS: Recent studies show that genomic instability in 50% of tumors can be attributed to increased transposon activity, but the the reasons for this activity are unknown. We have evidence of a novel mechanism linking adherens junctions with transposon regulation. We hypothesize that adherens junctions suppress transposons to maintain genomic integrity. METHODS/STUDY POPULATION: We observed co-localization of PIWIL2 with adherens junction components of well differentiated epithelial breast, kidney and colon cell lines MCF10A, MDCK and CACO2, respectively, through immunofluorescence staining, confocal microscopy, and co-immunoprecipitation studies. Breast cancer cell lines MCF7 and MDA-231 were also observed using immunofluorescence to determine the localization of PIWIL2 in cancer cell lines. shRNA knockdown of PIWIL2 in MCF10A cells, followed by western blot, immunofluorescence, and qRT-PCR was performed to confirm the knockdown, observe if transposons were upregulated, and determine the extent of DNA damage to the genome by the marker gamma-H2AX. RNA-seq will be performed to determine piRNA sequences and possible targets of PIWIL2. RESULTS/ANTICIPATED RESULTS: Our data have revealed an interaction of E-cadherin and p120 catenin, core components of adherens junctions, with PIWIL2, a member of the Argonaute family of proteins and a key component of the piRNA processing pathway that is responsible for transposon silencing. piRNAs (PIWI-interacting RNAs) are a distinct class of small RNAs that bind to PIWI proteins, and aid in transposon degradation. We found co-localization of PIWIL2 with E-cadherin and p120 catenin at adherens junctions of well-differentiated epithelial cells, whereas this association was lost in cancer cells. Furthermore, our data show that E-cadherin depletion results in mis-localization of PIWIL2 and TDRD1, another member of the PIWI complex. E-cadherin depletion also results in upregulation of transposons and ?-H2AX, an indicator of DNA damage. DISCUSSION/SIGNIFICANCE OF FINDINGS: Since both loss of junctional integrity and increased transposon activity are universal events in cancer, this study has the potential to further our understanding of the causes of tumorigenesis. Understanding the mechanisms of transposon regulation has the potential to lead to a therapeutic target in the future.

ABSTRACT IMPACT: This project aims to investigate the impact of spermine oxidase inhibition on amelioration of neuronal injury. OBJECTIVES/GOALS: Our group has recently described a series of triazole-based reversible inhibitors of spermine oxidase (SMOX) (Holshouser et al. 2019). The purpose of the current project is to optimize our most promising inhibitors by structural modification, and to determine whether they can reduce oxidative damage in models of neuronal injury. METHODS/STUDY POPULATION: A small number of SMOX inhibitors have been described in the literature, however, currently available inhibitors lack selectivity for the enzyme and are associated with dose-limiting toxicity. For this project we used multiple medicinal chemistry techniques to synthesize novel triazole-based analogs of our most potent inhibitors as potential SMOX inhibitors. In addition, we plan to utilize virtual and physical screening methods to identify new potential scaffolds. Compounds with demonstrated activity against SMOX via enzymatic assay will then be evaluated in a cell-based model of neuronal injury. In a preliminary study, we investigated the ability of hydrogen peroxide to induce SMOX expression in an SH-SY5Y neuroblastoma cell line using western blot. RESULTS/ANTICIPATED RESULTS: We found that cellular SMOX protein increases in response to hydrogen peroxide exposure in a dose-dependent manner, indicating that this may be a viable cellular model for testing the efficacy of our experimental compounds. To extend these studies, we have developed a SMOX enzymatic assay that will be used for high-throughput screening of commercial libraries, as well as the South Carolina Compound Collection (SC3), which contains 100,000 proprietary, fully annotated analogs. As hits are identified, they will be synthesized and evaluated for potency and selectivity as SMOX inhibitors. The most potent and selective compounds will then be evaluated in our cellular model of neuronal injury. DISCUSSION/SIGNIFICANCE OF FINDINGS: Studies have linked the overexpression of SMOX and the production of associated toxic byproducts with increased susceptibility to excitotoxic stress and neuronal injury. Our objective is to develop potent and selective inhibitors for this enzyme that can serve as chemical probes for elucidating the role of this enzymatic pathway in neuronal injury.

ABSTRACT IMPACT: Racial differences in the prevalence of hypertension and endothelial (dys)function are well established, yet research investigating the mechanism(s) underlying this disparity is still lacking. OBJECTIVES/GOALS: Investigate the influence of race and the effect of serum collected from hypertensive donors on Protein Phosphatase 2A (PP2A) and endothelial nitric oxide synthase (eNOS) expression and activity in human umbilical vein endothelial cells (HUVECs) from Caucasian (CA) and African American (AA) donors. METHODS/STUDY POPULATION: HUVECs from 3 CA & 3 AA donors were cultured in parallel. Experiments were conducted between passages 5-7. At ?90% confluency, cells were serum starved ˜12hrs prior to incubating for 24 or 48 hours in one of the following conditions: 1) Control (Fetal Bovine Serum), 2) serum from normotensives (NT; 5 CA & 5 AA donors), or 3) serum from hypertensives (HT; 5 CA & 5 AA donors). NT and HT serum was pooled from donors with the following characteristics: Male, 30-50 years, nonsmokers, no comorbidities, and non-obese (BMI < 30 kg/m2). Western blotting was used to measure protein expression of total eNOS, p-eNOSS1177, total PP2A, and p-PP2AY307. For activity p-eNOSS1177/total eNOS and p-PP2AY307/ total PP2A ratio was used. A two-way ANOVA was used for statistical analysis. RESULTS/ANTICIPATED RESULTS: Irrespective of the donors’ race, there was no influence of serum treatment or interaction effect in any of the measured proteins of interest. Moreover, compared to CA, HUVECs from AA had lower expression of eNOS irrespective of condition (race p=0.01). Compared to CA, HUVECs from AA tended to have lower expression of p-eNOSS1177 irrespective of condition (race p=0.07). However, there was no racial differences in eNOS activity (p=0.68). There was no racial difference in the expression of PP2A (p=0.35), p-PP2AY307 (p=0.30), or PP2A activity (p=0.97) in all conditions. DISCUSSION/SIGNIFICANCE OF FINDINGS: Our preliminary results suggest no influence serum constituents from hypertensive donors or race on PP2A or eNOS expression and activity in HUVECS. Future research should consider conducting proteomics profiling to compare NT and HT serum.

ABSTRACT IMPACT: If immune checkpoint blockade increases bacterial clearance with or without antibiotics in vitro, clinical application would be almost immediate and dramatic creating a seismic shift in the current therapeutic paradigm of periprosthetic joint infection. OBJECTIVES/GOALS: Periprosthetic joint infection (PJI) is a major cause of failure after joint replacement. Currently, the treatment of PJI relies on removing biofilm contaminated implants. Some of the bacteria within biofilm undergo a phenotypic shift becoming small colony variants (SCVs). SCVs induce local immunosuppression through PD-1/L1 signaling. METHODS/STUDY POPULATION: We will infect cultured human macrophages and bone marrow aspirate with stable Staphylococcus aureus SVCs and treat with anti-PD-1 or anti-PD-L1 monoclonal antibodies with and without antibiotics (e.g., gentamycin, cefazolin, vancomycin, rifampicin) and assess the residual bacterial viability. We will utilize multiplexed ion beam imaging to quantify PD-1/L1 expression in human tissue from patients with a chronic PJI and compare those to patients undergoing an aseptic revision. Patients with a chronic PJI are likely to have increased expression of PD-1/L1 as their tissue samples are prospectively screened. RESULTS/ANTICIPATED RESULTS: SCVs reduce the phagocytic activity of macrophages and can survive intracellularly. SCVs also induce anti-inflammatory M2-macrophage polarization and recruit a heterogeneous group of immature monocytes and granulocytes called myeloid-derived suppressor cells (MDSC) to the periprosthetic microenvironment. M2-macrophages and MDSCs then produce an immunosuppressive cytokine milieu characterized by increased IL-10 and decreased TNF-α. Clinically isolated SCVs up-regulate the expression of PD-L1 and PD-L2 on the surface of macrophages, representing a mechanism by which SCVs induce host immunosuppression and survive immune clearance. Our preliminary data show PD-L1 expression during septic PJI, but not in aseptic revisions. DISCUSSION/SIGNIFICANCE OF FINDINGS: If immune checkpoint blockade is shown to increase bacterial clearance with or without antibiotics, host immunomodulation would represent a novel class of therapeutic adjuvants to assist surgical debridement and antibiotic administration that could be superimposed on existing treatment algorithms to improve PJI related outcomes.

ABSTRACT IMPACT: The knowledge acquired from my research can inform the development of early diagnostic methods for HIV-associated neurocognitive disorders. OBJECTIVES/GOALS: In the era of combination antiretroviral therapy (cART), the prevalence of HIV-associated neurocognitive disorders (HAND) remains high but the neural mechanisms are unclear. We examined whether older people with HIV (PWH) with minimal cognitive impairment have reduced functional connectivity in frontostriatal circuits compared to controls. METHODS/STUDY POPULATION: 99 PWH (mean age 56.6 years, 75% male, 62% Black, mean duration of HIV-infection 26.2 years ±9.3, 90% viral load <50 copies, 98% on stable cART) and 38 demographically-comparable controls (mean age 54.5 years, 71% male, 58% Black) participated in a cross-sectional study. A 7-domain neuropsychological battery and an Activities of Daily Living index were used to determine HAND diagnoses: 32 PWH met criteria for asymptomatic to mild HAND. Motor skill was assessed using the Grooved Pegboard Test by measuring performance speed. Structural MRI and resting-state functional MRI were collected. Seed-to-voxel analyses were conducted using 4 distinct regions in the striatum as seed regions. We used a voxel threshold of p<0.001 and cluster threshold of p<0.05 (FDR-corrected) after controlling for demographic variables. RESULTS/ANTICIPATED RESULTS: Compared to controls, PWH had lower resting state functional connectivity between the default mode region of the striatum (i.e., medial caudate) and bilateral superior frontal gyrus, supplementary motor cortex and paracingulate gyrus (p<0.05; cluster size: 567 voxels). Also, compared to controls, PWH had reduced resting state functional connectivity between the motor division of the striatum (i.e., posterior putamen) and anterior cingulate cortex and left supplementary motor cortex (p<0.05, cluster size: 405 voxels). Performance speed on the Grooved Pegboard motor test negatively correlated with functional connectivity between the motor region of the striatum and supplementary motor frontal regions in all participants (Spearman’s rho=-0.18, p=0.04). DISCUSSION/SIGNIFICANCE OF FINDINGS: Our results support the hypothesis that frontostriatal abnormalities are widely present in PWH and might play a key role in HAND development. Our data suggest that dysfunction within the frontostriatal circuits may be involved in motor impairment in PWH, and ongoing inflammation may contribute to motor impairment and frontostriatal injury.

ABSTRACT IMPACT: Our data demonstrate that VC2 oncolytic virotherapy has significant clinical potential. OBJECTIVES/GOALS: Use our novel oncolytic herpes simplex virus type I (HSV-1), VC2, to understand how oncolytic virotherapy affects the immunosuppressive tumor microenvironment as a mechanism of efficacy. METHODS/STUDY POPULATION: We tested the efficacy of VC2 as an oncolytic virotherapy (OVT) in a syngeneic B16F10-derived mouse model of melanoma. We modified the B16F10 to express nectin-1 (B16F10n-1), the major receptor for HSV-1. Engrafted B16F10n-1 tumors were intratumorally treated with either phosphate-buffered saline (PBS) or 1x10^6 pfu VC2. At indicated time points, treated tumors were excised and processed for immunohistochemistry or flow cytometry analysis. For our experimental metastasis studies, mice were intravenously challenged with B16F10n-1 cells. For our depletion studies, CD4+ and CD8+ T cells were depleted in mice by treatment with mouse anti-CD4 and anti-CD8 monoclonal antibodies respectively, while the control mice were given Rat IgG2b isotype. RESULTS/ANTICIPATED RESULTS: We found that VC2 slowed tumor growth rates and significantly enhanced survival times over control treated mice. VC2-treated mice that survived initial tumor engraftment were able to reject a second tumor challenge and were also resistant to lung colonization (experimental metastasis) of tumor cells. Furthermore, VC2 treatment promoted increased intratumoral T cell infiltration and induced a strong antitumor effect that decreased growth rates of distant, untreated tumors. DISCUSSION/SIGNIFICANCE OF FINDINGS: Our data demonstrate that VC2 OVT has significant clinical potential. Furthermore, due to the increased survival rates and CD8+ T cells dependence, our model will enable study of the immunological correlates of protection for VC2 OVT and OVT in general, as well as to inform the rational design of future OVs with improved therapeutic potentials.

ABSTRACT IMPACT: This work will provide a rational approach to improve the efficacy of current immunotherapy approaches in patients that have historically responded poorly to immune checkpoint inhibitors. OBJECTIVES/GOALS: Recent evidence of immunogenic cell death as a predictor of response to therapy has increased the interest in monitoring the presence of damage-associated molecular pattern protein (DAMPs). By regulating DAMP expression, our lab is interested in discovering new ways to improve the patient response rate to immune checkpoint inhibition. METHODS/STUDY POPULATION: Using cultured cell, and a limited number of patient tumors and serum (n=4), we measured intracellular and extracellular levels of DAMP molecule, high mobility group box 1 (HMGB1) using enzyme-linked immunosorbent assays and immunoblots. Immunological assayed were compared to the expression of immune checkpoint molecules PD-1/PDL1 on patient tumors as presented in pathology reports. RESULTS/ANTICIPATED RESULTS: HMGB1 release was associated with increased levels of PD-L1 on tumor cells. Targeted inhibition of HMGB1 altered the expression of programmed death-ligand 1 (PD-L1), a target for immune checkpoint inhibition therapy. Patients with higher levels of PD-L1 possessed increased levels of HMGB1 in serum. DISCUSSION/SIGNIFICANCE OF FINDINGS: This implies that regulating the expression of HMGB1 could have an effect on the response of patients to immunotherapy. The main objective of the work is to determine the potential benefit of targeting HMGB1 to improve the efficacy of current therapeutic approaches to treating lung cancer.

ABSTRACT IMPACT: A mouse model of minimally-invasive chronic sleep deprivation is essential for elucidating the impact of sleep deprivation on various health issues, and it would lead to the possibility of sleep as a therapeutic target. OBJECTIVES/GOALS: The lack of sleep has been associated with various health conditions. In mice, sleep deprivation has been achieved mainly by physical disturbances, which raises concern about confounding effects by stresses. Without physical disturbance, targeted neuron ablation can address this methodological flaw. METHODS/STUDY POPULATION: AdultVgat-IRES-cre mice undergo a stereotaxic injection of adeno-associated virus (AAV) vector containing mCherry-dtA to bilateral parafacial zone (PZ) to perform GABAergic neuron-specific cell ablation. Control mice receive an injection of AAV vector containing hSyn-DIO-mCherry. All mice are implanted with electroencephalogram and electromyogram (EEG/EMG) electrodes for sleep-wake analysis. After 7-10 days of the postoperative recovery period, mice are kept individually in a cage for sleep-wake state recording. EEG/EMG and video recording are used to measure total wake time, total sleep time, percent of rapid eye movement (REM) and non-REM sleep, and detailed characterization with spectral analysis. RESULTS/ANTICIPATED RESULTS: We anticipate that the ablation of GABAergic neurons in bilateral PZ decreases the fraction of sleep state in mice, especially non-REM sleep. In the Vgat-IRES-cre mice that received the injection of AAV vector containing mCherry-dtA, total sleep time is expected to be decreased constantly during the 8-week observation period. Sleep-wake staging by video activity recording is anticipated to be closely correlated with the gold standard staging by EEG/EMG. Possible stresses caused by the restriction of physical activity and handling of mice for EEG/EMG recording can be further minimized by the sleep-wake staging performed with the video activity recording. DISCUSSION/SIGNIFICANCE OF FINDINGS: The lack of sleep has been associated with negatively affecting overall health and is implicated in major health conditions including obesity, diabetes, and cardiovascular diseases. This chronic sleep deprivation mouse model can be used to understand the mechanisms of such detrimental effects on health, and would improve many health conditions.

ABSTRACT IMPACT: We hope to provide a more nuanced understanding of the type-III IFN system, thereby exploring its therapeutic potential in the realm of infectious diseases. OBJECTIVES/GOALS: The role of IFNLR1 receptor dynamics and plasticity in regulating the type-III IFN response is largely unknown. As a specific, powerful component of innate immunity, understanding how the type-III IFN system is regulated could lead to the development of novel therapeutic targets and strategies to face a multitude of viral illnesses. METHODS/STUDY POPULATION: To facilitate our investigation, we will generate doxycycline-inducible FLAG-tagged IFNLR1-expression plasmids representing all known transcriptional variants. These plasmids will allow us to: 1) Evaluate the effect of IFNLR1 surface abundance on the type-III IFN transcriptional profile and 2) Assess the extent of IFNLR1-FLAG co-localization with several notable intracellular structures using immunofluorescence, before and after stimulation with IFNL3. RESULTS/ANTICIPATED RESULTS: We have successfully generated three IFNLR1-FLAG transcriptional variants and confirmed inducible-expression and function in vitro. We are currently assessing the role of surface abundance, internalization, differential isoform expression, and trafficking. DISCUSSION/SIGNIFICANCE OF FINDINGS: By completing this study, we hope to provide a more nuanced understanding of the type-III IFN system, thereby exploring its therapeutic potential in the realm of infectious diseases.

ABSTRACT IMPACT: Our data reveal a histone modifying enzyme involved in regulating inflammation that may be a novel target for treating non-healing diabetic wounds. OBJECTIVES/GOALS: We investigate molecular mechanisms that regulate the inflammatory phenotype of macrophages in normal and diabetic wound healing. Our goal is to identify novel pathways that may be used to better treat diabetic patients with non-healing wounds. METHODS/STUDY POPULATION: We utilize normal and transgenic murine models on standard chow or high-diet to identify chromatin modifying enzymes involved in regulating macrophage function during wound healing. We validate our murine studies with human blood monocytes or wound macrophages from diabetic patients undergoing limb amputation surgery. RESULTS/ANTICIPATED RESULTS: We have identified the histone methyltransferase SETDB2 as a regulator inflammation in normal and diabetic wound macrophages. We found that SETDB2 was dependent on IFNβ singaling and that both IFNβ and Setdb2 expression were impaired in diabetic wound macrophages. Further, we show that SETDB2 regulates inflammatory response and immune cell trafficking pathways. We also show that SETDB2 genomic localization is dependent on *NFκΒ deposition of the promoter. DISCUSSION/SIGNIFICANCE OF FINDINGS: Our results indicate that SETDB2 is a regulator of macrophage plasticity and that SETDB2 expression is impaired in diabetic wound macrophages leading to hyper-inflammatory response and delayed wound healing. These data provide a novel potential therapeutic pathway for treating non-healing diabetic wounds.

ABSTRACT IMPACT: Identifying an important pathway in treatment resistant TNBC will allow for the future development of clinical therapeutics specific for this disease. OBJECTIVES/GOALS: Triple Negative Breast Cancer (TNBC) is a subtype of breast cancer characterized by negative expression of estrogen receptor, progesterone receptor, and HER2/neu amplification. It resists therapies and has a high recurrence rate after resection. The goal of my research is to identify & characterize a TNBC pathway for future development of therapies. METHODS/STUDY POPULATION: The project uses a combination of cell lines, patient derived xenograft (PDX) models, as well as patient databases. Standard cellular and molecular biology techniques will be used including: Cell culture, qPCR, western blotting, and flow cytometry. RESULTS/ANTICIPATED RESULTS: LKB1 is a master kinase that activates 14 possible downstream kinases. The signaling pathway has been demonstrated to play a role in energy homeostasis and metabolism. Mutation of LKB1 signaling results in Peutz-Jeghers Syndrome and is associated with neoplasias of the lung, pancreas, and breast. Based on preliminary analysis, overexpression of LKB1 by shRNA in TNBC cell lines results in suppression of EMT and reduction of the cancer stem cell population. Additional studies show that LKB1 overexpression has no effect on growth rate in 2D culture while significant reduction in 3D mammosphere formations can be seen. Downstream studies using commercially available SIK1 inhibitor HG-9-91-01 is able to induce a larger fraction of CSC from reduced LKB1 overexpression as well as from baseline levels. DISCUSSION/SIGNIFICANCE OF FINDINGS: Overall, our results suggest that LKB1 acts through SIK1 to suppress EMT and the generation of cancer stem cells. This results in reduced cancer functionality, as evidenced by inhibition of mammosphere formation. These results establishes a foundation for future mechanistic studies on the LKB1 axis and its mechanisms in TNBC.