Risultati per: Probiotici: in vivo vs in vitro

Circulation, Volume 146, Issue Suppl_1, Page A13417-A13417, November 8, 2022. Introduction:The asialoglycoprotein receptor-1 (ASGR-1) is known to be a hepatic receptor that clears desialylated glycoproteins from the circulation. A loss-of-function mutation in ASGR-1 was reported to associate with a 34% reduction in coronary artery disease (CAD) risk, suggesting a role for ASGR-1 in CAD.Hypothesis:ASGR-1 is an important player in atherosclerosis and deletion of ASGR-1 will reduce atherosclerotic plaque via athero-protective mechanisms in macrophages.Methods and Results:Using immunofluorescence, we detected ASGR-1 in aortic sinus plaques from apolipoprotein (Apo)e-/- mice fed a high cholesterol diet (HCD)-fed apolipoprotein (Apo)e-/- mice. Bone marrow-derived macrophages (BMDMs) from Asgr1-/- mice elicited greater cholesterol efflux (39%, P

Circulation, Volume 146, Issue Suppl_1, Page A11462-A11462, November 8, 2022. Introduction:Surgical Myectomy (SM) is the gold standard treatment for hypertrophic obstructive cardiomyopathy (HOCM). However, alcohol septal ablation (ASA) has emerged as an alternative option for selected patients. Nonetheless, the long-term efficacy and safety of ASA have been debated in recent years. The aim of this metanalysis is to evaluate the long-term outcomes of ASA vs SM in HOCM patients.Hypothesis:ASA is a safe and effective alternative to SM in HOCM.Methods:: Unrestricted searches of the PubMed, EMBASE, and Cochrane databases from inception till June 1, 2022, for studies comparing long-term outcomes of ASA with SM in HOCM patients. Relevant data were extracted and analyzed using Revman 5.3 software. Odds Ratio (OR) and 95% Confidence interval (CI) were calculated using the random-effects model.Results:: A total of 12 retrospective studies were included examining 7,599 HOCM patients (2,010 ASA vs 5,589 SM). After a mean follow-up of 5.04 years, all-cause mortality was similar between the two groups (OR 1.18; 95% CI 0.60-2.29). However, ASA was associated with high rates of reinterventions (OR 15.68; 95% CI 6.71-36.61), and pacemaker insertion (OR 2.74; 95% CI 1.39-5.41).Conclusions:Although there was no difference in mortality between ASA and SM, ASA was associated with higher rates of reinterventions and pacemaker insertion in long-term follow-up. Therefore, the selection of septal reduction therapy in HOCM should be individualized and should be performed in a comprehensive center after detailed risk and benefits discussions with an experienced team.

Circulation, Volume 146, Issue Suppl_1, Page A13973-A13973, November 8, 2022. IntroductionPathological cardiac hypertrophy has not been fully recapitulated in thein vitrosettings. Currently usedin vitromodels are presumably oversimplified since the vast majority are based on iPSC-derived cardiomyocytes (CMs) exclusively and do not include any cardiac non-myocytes. The aim of this study was to generate engineered heart tissues (EHTs) containing five hiPSC-derived cardiac cell types, i.e., CMs, endothelial cells (ECs), macrophages (Mϕs), fibroblasts (FBs), and smooth muscle cells (SMCs) and treat them with prohypertrophic compounds.Methods:Mesoderm induction preceded all cell-type-specific differentiation steps. CMs were then generated by Wnt signaling inhibition and ECs by VEGF stimulation. Mϕ differentiation required treatment with IL-3+M-CSF. FBs and SMCs were generated by Wnt pathway activation followed by bFGF or TGFβ+bFGF stimulation. The characterization of different iPSC-derivatives and EHTs was based on the MICS (MACSima Imaging Cycling Staining) technology and profiling of hallmark genes and proteins. To study the response to prohypertrophic stimuli, EHTs were treated with 20 μM phenylephrine (PE) and 50 nM endothelin-1 (ET-1) for 9-10 days.Results:The expression of cell-type-specific markers and functional assays were the determinants of successful differentiation. For instance, CMs were identified based on cTnT expression and contractile capabilities, Mϕs by expression of CD68 and phagocytic activity, and ECs by CD31 expression and tube formation abilities. Multi-cell-type EHTs were assembled from 60% CMs, 20% ECs, 10% Mϕs, 5% FBs and 5% SMCs. These EHTs displayed accelerated development, i.e., faster remodeling and earlier onset of beating compared to CM-only EHTs. Preliminary results show that multi-cell-type EHTs exhibited higher maximal forces and increased stiffness compared to CM-only controls. The exposure to PE+ET-1 led to a decrease in force, activation of the hypertrophic gene program, and elevation of NT-pro BNP production.Conclusions:We successfully generated functional multi-cell-type EHTs containing five hiPSC-derived cardiac cell types. Upon hypertrophic stimulation, these EHTs developed a pathological phenotype that resembles the hallmarks of a failing human heart.

Circulation, Volume 146, Issue Suppl_1, Page A15024-A15024, November 8, 2022. Introduction:LDL transports dietary long chain fatty acids, constituents that may influence rates of lipid oxidation. Modified LDL promotes foam cell formation during atherosclerosis. The omega-3 fatty acid (n3-FA) eicosapentaenoic acid (EPA) administered as icosapent ethyl (IPE), reduced cardiovascular events in REDUCE-IT compared to mixed n3-FAs in similar high-risk patients (STRENGTH). Some have attributed these discordant outcomes, in part, to placebo choice (mineral versus corn oil) despite very limited oral absorption. We compared the effects of these oils and various FAs on rates of LDL oxidation at supra-pharmacologic doses.Methods:LDL was isolated from human plasma by isopycnic centrifugation, separated into test samples of 100 μg/mL before being incubated at 37°C for 30 min with pharmaceutical grade mineral or corn oil at high concentrations (100 μg/mL) that are comparable to treatment achieved n3-FAs (4 g/d) that have high oral absorption. We also tested FAs contained in these oils, including stearic acid (18:0), arachidic acid (20:0), and linoleic acid (18:2, n-6) as well as ascorbic acid (10 μM) and a water-soluble analog of vitamin E (Trolox, 10 μM) as controls. All samples then underwent copper-induced oxidation (20 μM) monitored by formation of malondialdehyde (MDA).Results:MDA formation increased from 0.28 ± 0.03 to 9.96 ± 0.58 μM (p

Circulation, Volume 146, Issue Suppl_1, Page A11397-A11397, November 8, 2022. Introduction:TOTUM-070 is a patented polyphenol-rich compound which has shown hypocholesterolemic properties in preclinical studies. However, clinically validated approaches and further investigations on the mode of action at cellular level especially in humans are required for optimized care management. In this study, we designed an ex-vivo clinical innovative approach considering the metabolites produced by the digestive tract following the ingestion of TOTUM-070 in humans.Methods:Human serum was collected in healthy subjects before and following acute intake of 5g of TOTUM-070. Availability of circulating metabolites was confirmed and characterized by UPLC-MS. Human serum enriched with metabolites deriving from TOTUM-070 absorption was further incubated with human hepatocytes, pretreated or not with palmitate (250 μM). In such lipotoxic environment, hepatocyte behavior was monitored to determine whether and how TOTUM-070 metabolites may improve cholesterol metabolism in human.Results:In the presence of the human metabolites from TOTUM-070, human hepatocytes were protected from an induced lipotoxic stress. No effect on cell toxicity was detected in the presence of enriched sera. Hepatocyte protection was characterized by (1) the inhibition of both triglycerides (-41%, p

Circulation, Volume 146, Issue Suppl_1, Page A12656-A12656, November 8, 2022. Introduction:Pulmonary vein isolation (PVI) remains the cornerstone of atrial fibrillation (AF) ablation procedures. Because many patients have continued AF after PVI alone, posterior wall isolation (PWI) has been proposed as an adjunctive strategy to PVI. We conducted a meta-analysis of available data to assess the incremental impact of PWI based on whether patients had paroxysmal or persistent (PAF, PeAF) AF.Objective:To evaluate the incremental impact of PWI following PVI in patients with PAF and PeAF.Methods:The online databases (Pubmed, Medline, Embase) were searched using the terms “pulmonary vein isolation”, “posterior wall isolation”, or “posterior wall ablation”. Out of 1843 studies, 11 met our strict criteria (Table). Specifically, patients were undergoingde novoablation for treatment of PAF or PeAF using either cryoballoon or radiofrequency energy. Patients had PVI +/- PWI; studies that included additional ablations (except for cavotricuspid isthmus ablation) were excluded. The primary outcome was long-term freedom from recurrence of any atrial tachyarrhythmia (AT).Results:The cohort consisted of 1702 patients (65 ± 18 years, 75% male); 1404 (82%) pts with PeAF and 298 (18%) pts with PAF (Table). In the PeAF group, AT recurrence was significantly higher in patients who underwent PVI alone as compared to those who also had PWI (OR 1.85, 95% CI [1.23, 2.77], P = 0.003, Figure). In contrast, in the PAF group, outcome was similar in patients who did and did not undergo PWI in addition to PVI (OR 0.95, 95% CI [0.53, 1.72], P = 0.86, Figure).Conclusions:PWI was rarely used during thede novoablation procedure in PAF patients and did not seem to impart additional benefit. In contrast, PeAF patients seemed to derive favorable impact from the addition of PWI to PVI. Additional randomized studies are needed to determine the role of PWI in PeAF patient undergoing de novo ablation for management of AF.

Circulation, Volume 146, Issue Suppl_1, Page A15172-A15172, November 8, 2022. Introduction:Segmenting cardiac computed tomography (CT) to provide anatomic guidance for Atrial Fibrillation (AF) ablation is routinely applied, but is time-consuming and prone to error. Machine learning (ML) is a powerful approach that could automate this approach, but is hindered by the small size of available labeled datasets.Hypothesis:We hypothesized that a new computational pipeline, in which an ML model is trained mathematically in a small cohort (N=20) using geometrical heart avatars derived from computer graphics imaging (CGI), rather than on manually-segmented data, would enable rapid expert-level segmentation of raw cardiac CT scans.Methods:We first encoded anatomical knowledge with generic geometrical avatars and derived a “virtual dissection” method to geometrically parse the heart (Fig A). An ML model trained by virtual dissection using 20 cases was able to rapidly and accurately segment the pulmonary veins (PVs), left atrial appendage (LAA), and left atrium (LA) from cardiac CT scans (Fig B), which we tested in a retrospective study of N=100 patients (30% women, 64.7±10.1Y) and in a prospective clinical trial of N=42 patients (42.9% women, 65.2±10.8Y) undergoing AF ablation, against a panel of 3 experts (Fig C).Results:In a retrospective study (N=100), ML achieved median Dice scores of 96.6% (IQR: 95.1% to 97.5%), similar to experts (p

Circulation, Volume 146, Issue Suppl_1, Page A14818-A14818, November 8, 2022. Introduction:Endothelial mechano-transduction mechanisms are instrumental to vascular health and disease. Novel strategies targeting disease-causing mechano-sensitive pathways in dysfunctional endothelial cells could revolutionize future cardiovascular therapeutics. Vascular complications such as atherosclerosis and stenosis preferentially develop at arterial curvatures and bifurcations where endothelial cells are activated by local disturbed blood flow, leading to peripheral artery disease, carotid artery disease and ischemic stroke.Hypothesis:Current vascular therapies mainly target systematic risk factors (e.g. hypercholesterolemia and hypertension) but not the diseased vasculature, distinct molecular/cellular signatures of which can be targeted by innovated precision nanomedicine approaches.Methods:We first elucidated novel mechano-sensitive molecular mechanisms in endothelium activated by disturbed flow (DF) and then engineered rationally-designed nano-materials with purposed-constructed functionalities to deliver therapeutic nucleotides to DF-activated endothelial cells.Results:Our results elucidated previously unrecognized endothelial mechano-sensitive pathways in endothelial activation, with emphasis upon cellular metabolism (DF-induced glycolysis), human genetic variants (DF-induced suppression of PLPP3, a CAD GWAS gene), miRNA, protein stability (DF-induced NOS3 protein degradation via TXNDC5) and mRNA chemical modification/epi-transcriptome (DF-induced suppression of m7G). VCAM1-targeting nanoparticles were engineered to deliver therapeutic nucleotides such as mRNA, miRNA inhibitor, or CRISPR/Cas9 constructs specifically to inflamed endothelial cells to intervene aforementioned mechano-sensitive pathways, effectively reducing atherosclerosis and stenosis in mice. Similar approaches were very effective to promote endothelial health and lessen acute respiratory distress syndrome (ARDS) in mice induced by influenza or SARS-CoV-2 viruses.Conclusions:These results elucidate novel endothelial mechano-sensing mechanisms and provide a proof of concept of innovative targeted nanomedicine approaches, addressing an unmet medical need in vascular therapies.

Circulation, Volume 146, Issue Suppl_1, Page A13281-A13281, November 8, 2022. Introduction:Our previous study demonstrated that fibroblasts can be reprogrammed into induced cardiovascular progenitor cells (iCPCs) by a CRISPR activation approach. However, it is still unknown whether in vivo iCPC reprogramming can be achieved by direct activation of endogenous genes.Hypothesis:Direct activation of endogenous loci by using CRISPR tools targeting genomic DNA can fulfill in vivo iCPC reprogramming to repair infarcted hearts.Methods:A new fibroblast-specific CRISPRa model (Col1a2-cre/ERT;CAG-cas9) was generated. SgRNAs targeting the core promoter region ofGata4, Isl1, Nkx2-5, Baf60c,orTbx5were locally introduced through an AAV system in MI mice that were created by permanent LAD ligation. Heart function was measured by echocardiography and tissue sections were harvested for immunostaining. Cardiovascular cells derived from iCPCs were determined by immunostaining, ex vivo characterization, and electrophysiological assay.Results:The CRISPR system was activated in ~50% of fibroblasts after tamoxifen induction. The lineage conversion into iCPCs was identified by the Nkx2.5-eGFP reporter. eGFP+ cells were expressing proliferative markers (Ki67 and Pcna) and aggregated into spheres during suspension culture after sorting. Progenitor markers (Flk1, Ssea1, and Pdgf-α) were co-expressed in eGPF+ cells. The ejection fraction and scar formation of infarcted hearts were improved after injection of sgRNA-AAVs for 4 weeks. The engrafted iCPCs were identified by the lineage-tracing reporter and differentiated into cTnT+ cardiomyocytes, α-SMA+ smooth muscle cells, or CD31+ endothelial cells in infarcted hearts.Conclusions:Activation of endogenous loci enables in vivo iCPC reprogramming for cardiac regenerative medicine.

Circulation, Volume 146, Issue Suppl_1, Page A12802-A12802, November 8, 2022. Introduction:Limited access is a key challenge in the management of chronic diseases, like heart failure (HF), in rural areas. Telehealth (TH), which is the delivery of care via remote technologies, and remote monitoring (RM), which allows a patient’s implanted device to be interrogated at a distance, are potential ways to improve access. However, many older adults live in rural areas and age is negatively associated with the adoption of novel technologies. The aim of this study is to understand the association between age and use of TH and RM in urban vs. rural areas.Methods:We created annual, cross-sectional cohorts of patients with HF in each year from 2013 to 2018 with approximately 5 million patients/year by requiring ≥1 inpatient or ≥2 outpatient ICD9/10 codes for HF in the 2 years prior. TH and RM use were determined using validated ICD-9/10 and CPT codes. Rurality was determined using the Rural/Urban Commuting Areas (RUCA) classification. Multivariable, logistic regression models were used to determine the association between age and use of TH and RM in urban vs. rural areas.Results:Increasing age was associated with a decreased odds of TH use in both urban and rural areas. However, the decline in use with age was greater in urban (OR=0.41 for 85+ vs 65-69) than rural areas (OR=0.65). In contrast, increasing age was associated with an increased odds of RM in both urban and rural areas, with a larger increase with increase age in rural (OR=1.47 for 85+ vs 65-69) compared to urban areas (OR=1.35).Conclusion:TH and RM are viable ways to improve access for rural patients with HFrEF across the age spectrum. With increasing age, TH use decreases but RM increases, suggesting that patients’ ability to navigate technology plays a significant role – TH technology requires more active engagement by the patient compared to RM technology. Efforts to simplify TH technology would likely mitigate the drop in TH use seen with increasing age and improve access to care for older adults with HFrEF.

Circulation, Volume 146, Issue Suppl_1, Page A12829-A12829, November 8, 2022. Introduction:There is an urgent need for a reliablein vitrosystem to accurately replicate the cardiac physiological and pathological environment for drug testing. The limited availability of human heart tissue culture systems has led to inaccurate interpretations of cardiac-related drug effects. Our group developed a culture system for pig/human heart slices that enables functional and structural viability for 6 days using continuous electrical stimulation and enriched media. This culture system can more reliably detect cardiotoxic effects compared to hiPSC-CMs. However, by day 10, the slices undergo cardiomyocyte dedifferentiation and fibrotic remodeling making them inadequate for long-term drug testing.Hypothesis:To determine whether incorporating physiological mechanical, and humoral cues within the culture system can fully emulate cardiac physiology and pathophysiology in culture.Methods and results:We have developed a novelcardiactissueculturemodel (CTCM) that can electro-mechanically stimulate heart slices with physiological (0 to 80 mmHg) preload and afterload during each cardiac cycle. After 12 days in culture, this approach alone partially improved the viability of heart slices but did not maintain the structural integrity. Therefore, following a small molecule screening, we found that incorporating 100 nM tri-iodothyronine (T3) and 1 μM dexamethasone (Dex) into our culture media preserved the structural integrity of the slices for 12 days. When combined with T3/Dex, the CTCM system fully maintained the transcriptional profile, viability, metabolic activity, and structural integrity for 12 days at the same levels as fresh heart tissue. Furthermore, to test the ability of the CTCM to emulate cardiac hypertrophy, increasing the peak pressure to 140 mmHg resulted in induced cardiac hypertrophy within 6 days in culture as indicated by a 3-fold increase in NT-ProBNP release, increased NFATC4 and P-ERK expression, and increased cardiomyocyte cross-sectional area.Conclusions:This new CTCM heart slice culture system incorporating physiological electromechanical and humoral cues can emulate cardiac physiology and pathophysiology in culture, which could be used for drug screening for new therapeutics and cardiotoxins.

Circulation, Volume 146, Issue Suppl_1, Page A15873-A15873, November 8, 2022. Introduction:Takotsubo Syndrome (TTS), also known as stress-induced cardiomyopathy can be primary/idiopathic or secondary to physical stressor including acute illness. There is limited data on cardiovascular outcomes among primary TTS (pTTS) and secondary (sTTS).Methods:The National Inpatient Sample from the year 2016 to 2019 was queried to assess outcomes in pTTS and sTTS. The primary outcome was all-cause mortality, and secondary outcomes were acute kidney injury (AKI) heart failure (HF), stroke, cardiogenic shock (CS), and sudden cardiac arrest (SCA).We did trend analysis of outcomes, length of stay (LOS) and inflation adjusted hospital charges. The primary analysis used was pearson chi-Square, linear regression, and multivariate matching using STATA 17MP.Results:A total of 158,715 patients (pTTS n= 57,560 (38%); sTTS n= 101,155 (62%)). The cohorts were female predominant. On univariate and chi-square linear regression, we found higher odds and incidence of all-cause mortality, AKI, heart failure, and stroke in sTTS as compared to pTTS. After matching for confounding variables, all-cause mortality (OR 1.3; CI 1.1 – 1.56; p < 0.001), and AKI (OR 1.10; CI 1.03 - 1.03; p < 0.001) was still high in sTTS, but interestingly HF (OR 0.93; CI 0.88 - 0.99 ; p = 0.023), stroke (aOR 0.50; CI 0.43-0.59; p < 0.001), and MCS (aOR 0.61; CI 0.47-0.79; p < 0.001) were lower in sTTS as compared to pTTS. There was no difference in CS and SCA between pTTS and sTTS. Self-pay and prior CABG were most predictive of mortality for sTTS. Yearly trend analysis showed an uptrend for all non-HF outcomes in both pTTS and sTTS, a stable trend for HF, while trends showed higher incidence of CS in sTTS as compared to pTTS. Mean LOS and inflation adjusted hospital charges were higher in sTTS compared to pTTS.Conclusions:sTTS have worse cardiovascular outcomes as compared to pTTS and associated with higher inflation adjusted hospital charges and length of stay likely due to critical underlying primary illness.

Circulation, Volume 146, Issue Suppl_1, Page A14592-A14592, November 8, 2022. IntroductionSodium abnormalities are commonly associated with congestive heart failure (CHF). The main objective of this study is to analyze the impact of hyponatremia vs. hypernatremia on in-hospital outcomes in patients admitted with CHFMethodsThe National inpatient sample (NIS) data from 2017 to 2018 were queried using International Classification of Diseases 10 (ICD-10-CM) codes E871 and E870. Demographics and hospital characteristics were compared along with In-hospital mortality, length of stay (LOS), and total charge. The outcomes were measured using linear and logistic regression models to adjust the odds ratio for confounders.Results:A total of 350,144 patients with heart failure as a primary diagnosis (42% systolic and 32% diastolic HF) were included in the study. Among them, 37,129 (10.7%) had hyponatremia while 5839 (1.8%) had hypernatremia. In-hospital mortality rates were significantly higher with an adjusted odds ratio (OR) of 2.78 (p

Circulation, Volume 146, Issue Suppl_1, Page A13987-A13987, November 8, 2022. Background:Several studies have shown the cost-effectiveness of direct oral anticoagulants (DOACs), compared with warfarin, to prevent atrial fibrillation (AF) related complications. However, few have reported cost-effectiveness of DOACs in AF patients with intermediate stroke risk. Thus, we investigated the cost-effectiveness of DOACs vs. warfarin in non-valvular AF patients with intermediate stroke risk using national representative data.Methods:We identified 7,954 newly diagnosed non-valvular AF patients (≥18 years) with intermediate stroke risk (CHA2DS2-VASc score: 1 for men and 2 for women) using the national healthcare utilization data from August 1, 2016, to July 31, 2019. Annual incidence rate of AF-related composite outcomes (heat failure, myocardial infarction, ischemic stroke, intracerebral hemorrhage, and gastrointestinal bleeding) was estimated. Cost-effectiveness was estimated using a Markov chain model with the transition probability of 1 year. The willingness-to-pay (WTP) was set at $32,000 per quality-adjusted life-year (QALY) gained.Results:The total cost of warfarin, rivaroxaban, apixaban, dabigatran and edoxaban was $2,874, $5,761, $5,151, $5,761 and $5,851, respectively. The QALYs gained were 10.83, 10.95, 11.10, 10.49 and 10.99 years, respectively. The incremental cost-effectiveness ratio of rivaroxaban, apixaban, dabigatran and edoxaban was $29,743.99, $8,426.71, -$8,483.04 and $18,483.55, respectively. The WTP was set at $32,000. DOACs (except dabigatran) were more cost-effective compared with warfarin because they did not exceed the WTP in the base-case analysis.Conclusion:Our findings showed that DOACs were more cost-effective than warfarin in non-valvular AF patients with intermediate stroke risk.Figure 1. Cost-effectiveness acceptability curve of Warfarin vs. DOACs in AF patients with intermediate stroke risk.

Circulation, Volume 146, Issue Suppl_1, Page A12045-A12045, November 8, 2022. Introduction:The Ca2+ channel CaV1.2 is an essential part of excitation contraction coupling, neurotransmission and vascular tone. Identifying protein partners of CaV1.2 is critical to make mechanistic insights into these fundamental processes. Prior CaV1.2 proximity proteomes used APEX labeling, which labels other amino acids, introduces oxidative stress and is catalyzed ex vivo.Hypothesis: α1C-TurboID knockin rats can generate tissue specific interactomes in vivo, in cells with intact cell and matrix contacts, which may differ substantially from interactomes made from ex vivo peroxidase catalyzed labeling.Methods:CRISPR/Cas9 homology directed repair (HDR) was applied to rat spermatogonial stem cells with a targeting vector that includes cacna1c exon 44, coding the C-terminus of CaV1.2, and birA*, which codes TurboID, cloned 3’ to the stop codon (Fig A). Figures were made with Biorender.Results:Streptavidin blotting of brain and heart lysates demonstrated robust biotinylation in knockin rats (Fig B). In paced heart myocytes, α1C-TurboID produces Ca2+ transients and responds appropriately to adrenergic stimulation (Fig C), indicating proper localization to the sarcolemma. Expression of α1C-TurboID does not alter systolic function (Fig D). Mass spectrometry of heart lysates affinity purified on streptavidin beads identified 629 proteins, of which 454 were significantly enriched in knockin rats. These include known sarcolemmal proteins and interactors of CaV1.2 (Fig E), which was confirmed by antibody detection (Fig F). 73% of these 454 proteins were not significantly enriched in the APEX-α1C proteome.Conclusion:TurboID fusion to CaV1.2 generates a reliable and substantially different proteome compared to other techniques. Successful in vivo characterization of the channel interactome confirms α1C-TurboID rats will be a powerful tool for identifying changing protein networks across developmental stages, tissues, and disease models.

Circulation, Volume 146, Issue Suppl_1, Page A12697-A12697, November 8, 2022. Introduction:The co-chaperone Bcl2-associated athanogene-3 (BAG3), along with its cofactor heat shock protein 70 (HSP70), is fundamental for protein quality control and cell survival in a healthy heart. However, elevated expression of BAG3 is also associated with metastasis in breast and other cancers, and small molecules such as JG-98 that disrupt BAG3-HSP70 binding have been shown to reduce cancer cell proliferation. We previously showed JG-98 is cardiotoxic in neonatal rat ventricular myocytes.Hypothesis:As BAG3-HSP70 is fundamental for autophagic protein turnover, JG-98 will reduce tumor size but have cardiotoxic effects.Methods:BT474 Resistant breast cancer cells were injected bilaterally into mammary fat pads of female athymic nude mice. When tumors reached 25 mm2, mice received a baseline echocardiography and were randomized to intraperitoneal injections of either PBS/DMSO vehicle or 3 mg/kg JG-98 twice weekly for 3 weeks (n = 4/group) or 6 weeks (n=10/group). Tumor growth was monitored using calipers and echocardiography was performed prior to sacrifice.Results:After 3 weeks, tumor volume increased by ~44% in Vehicle treated mice but decreased by 17% in JG-98 treated mice, effectively halting tumor growth. However, cardiac echocardiography did not reveal any functional or structural differences between the vehicle and JG-98 treated mice after either 3 or 6 weeks. JG-98 did result in dysregulation of BAG3 and its interactome in the LV. JG-98 slightly increased BAG3 levels in the LV at 3 weeks, but slightly decreased levels at 6 weeks. This agrees with data showing acute stress upregulates BAG3, but chronic stress downregulates it. Similarly, we found altered protein expression of the BAG3 binding partners HSBP8, HSPB5, and HSP70.Conclusions:JG-98 had no overt cardiotoxic effects, suggesting the adult heart may be resistant to disrupted BAG3-HSP70. However, we also observed dysregulated protein levels in the BAG3-mediated autophagy pathways that could precede dysfunction with more chronic treatment. Furthermore, mutations in BAG3 or altered expression levels could sensitize individuals to JG-98 treatment. Further work is necessary to understand the cardiac impact of cancer therapeutics that target BAG3.