tbuckley/cabot-search huggingface dataset:
Abstract Mo020: Loss of TRAF2 Signaling Mediates Mitochondrial Dysfunction in Doxorubicin-Cardiomyopathy
Authors: Lorrie Kirshenbaum, Rimpy Dhingra, Inna Rabinovich-Nikitin, Hongying Gang, Victoria Margulets, Abhinav Diwan, Ali Javaheri
Journal: Circulation Research (2024)

Rationale: Cytokines such as TNFα have been implicated in cardiac dysfunction and toxicity associated with doxorubicin (DOX). While TNFα can elicit different cellular responses including survival or death, the mechanisms underlying these divergent outcomes in the heart remains cryptic. The E3 ubiquitin ligase TRAF2 provides a critical signaling platform for K63 - linked ubiquitination of RIPK1, crucial for NF-kB activation by TNFα. Whether alterations in TNFα-TRAF2 signaling underlie the cardiotoxic effects of DOX, remains poorly understood. Results: In contrast to vehicle treated mice, severe ultrastructural defects including cytoplasmic swelling, mitochondrial perturbations, and elevated TNFa levels were observed in the hearts of mice treated with DOX. While investigating the involvement of TNFa in DOX cardiotoxicity, we discovered that in the absence of DOX, NF-kB was readily activated by TNFa. However, TNFα -mediated NF-kB activation was impaired in cardiac myocytes treated with DOX. This coincided with loss of K63- linked poly-ubiquitination of RIPK1, attributed to the proteasomal degradation of TRAF2. Further, TRAF2 protein expression was markedly reduced in hearts of cancer patients treated with DOX. Impaired TRAF2 signaling resulted in the activation of Bnip3 and mitochondrial perturbations, including disrupted bioenergetics, loss of membrane potential and permeability transition pore opening. We further established that the reciprocal actions of the ubiquitinating and de-ubiquitinating enzymes c-IAP1 and USP19 respectively regulated the proteasomal degradation of TRAF2 in DOX treated cardiac myocytes. Importantly, an E3 ligase mutant of c-IAP1(c-IAP1 H588A) or gain of function of USP19, prevented proteasomal degradation of TRAF2 and DOX -induced cell death. Further, wild type TRAF2 but not a RING finger mutant defective for K63 ubiquitination of RIPK1, restored NF-kB signaling and suppressed DOX-induced cardiac cell death. Finally, cardiomyocyte-restricted expression of TRAF2 (AAV9-TRAF2) in vivo protected against mitochondrial defects and cardiac dysfunction induced by DOX. Conclusions: Our findings reveal a novel signaling axis that functionally connects the cardiotoxic effects of DOX to proteasomal degradation of TRAF2. Disruption of the critical TRAF2 survival pathway by DOX, sensitized cardiac myocytes to TNFa mediated necrotic cell death.
Abstract Mo137: Modulation of the Inflammatory and Fibrotic Effects of Angiotensin on Cardiomyocytes through YAP-mediated Transcription.
Authors: Van Ninh, Cameron Brand, Melissa Barlow, Sidar Aydin, Jamie Francisco, Dominic Del Re, Joan Heller Brown
Journal: Circulation Research (2024)

Introduction: Signaling through the transcriptional co-activator Yes-associated protein (YAP) has been shown to protect the myocardium against ischemic or mechanical stress. Research Question: In light of the critical role of inflammation on adverse cardiac responses we examined the possibility that YAP regulates inflammatory responses to Angiotensin II (AngII)-mediated stress. Approach: Cardiomyocyte specific YAP-KO mice were generated, implanted with AngII minipumps, infused with AngII (1.5 mg/kg/min) or vehicle for periods of 3 hrs to 3 days and hearts collected for analysis. Results: YAP deletion markedly enhanced AngII-induced mRNA expression of pro-inflammatory cytokines and chemokines (e.g. CCL2, CXCL2, IL-6) at 3 or 24 hrs in the cardiomyocyte, but not non-myocyte cell fraction. Expression of mRNA for the hypertrophic genes ANP and MHC-β, in contrast, was decreased in YAP KO mice. After 3 days of AngII infusion there was enhanced mRNA for pro-fibrotic genes (Col1a1, Col3a1 and Periostin) and increased staining for COL1A1 and F4/80, indicative of increased fibrosis and inflammatory cell recruitment in the absence of YAP signaling. Single cell RNA sequencing revealed specific subsets of genes that were upregulated in the cardiomyocyte subcluster from YAP KO mice. These included pro-inflammatory cytokines, cJun family genes, TLR4 and, surprisingly, CaMKIId. Elevated activation of CaMKIIδ in response to AngII in YAP KO hearts was confirmed by increased phosphorylation of phospholamban. Cardiomyocytes expressing siYAP also showed enhanced expression of TLR4 and CaMKIIδ. Conclusion: Upregulated expression of cJun, TLR4 and CaMKII occurs in the absence of YAP and this conspires to create a greatly enhanced inflammatory milieu which fuels adverse responses to external insults. YAP activation serves to suppress these responses and thus temper development of maladaptive inflammation.
Abstract Mo004: The Protective Effects of Empagliflozin in Carfilzomib-induced Cardiotoxicity in Mice: Unveiling the Crosstalk between Oxidative Stress, Inflammation, Endoplasmic Reticulum Stress, and Autophagy Axes.
Authors: Mina Y. George, Mohamed Dabour, Eman Rashad, Beshay Zordoky
Journal: Circulation Research (2024)

Introduction: Multiple myeloma ranks as the second most prevalent hematologic cancer in the US. Survival rates have significantly improved owing to advances in chemotherapy treatment. Carfilzomib, an irreversible proteasome inhibitor, has been used globally for the treatment of multiple myeloma. Unfortunately, its clinical use has been linked to cardiovascular complications. Empagliflozin is a sodium glucose co-transporter-2 inhibitor with potential cardioprotective activities, for which it is approved for heart failure management. Aims: The current study determined the beneficial effects of Empagliflozin against Carfilzomib-induced cardiotoxicity in C57BL/6 mice and the possible underlying mechanisms. Methods: Thirty-two mice were randomly divided into four groups and treated for two days as follows: Control (vehicle), Empagliflozin (10 mg/kg, oral), Carfilzomib (8 mg/kg, i.p.), and Carfilzomib + Empagliflozin groups. Results: The impact of Carfilzomib and Empagliflozin treatment on markers of cardiotoxicity and heart tissue architecture was assessed. Empagliflozin corrected histological alterations, CK-MB activity, and troponin I level induced by Carfilzomib. Additionally, Empagliflozin mitigated Carfilzomib-induced oxidative deficits via its effect on catalase activity, reduced glutathione level, and superoxide dismutase activity, restoring the balance of redox circuit. Moreover, Empagliflozin averted Carfilzomib-induced inflammatory response as evidenced by reducing nuclear factor-κB (p65), tumor necrosis factor-α, and interleukin-1β levels. Mechanistically, a substantial amelioration in the activating transcription factor 6-mediated endoplasmic reticulum stress was demonstrated with Empagliflozin treatment owing to its effect on glucose regulated protein-78, activating transcription factor-6, and C/EBP homologous protein. Intriguingly, the induction of autophagy by Carfilzomib was notably amplified following Empagliflozin administration as evidenced by higher mRNA expression of LC3B and beclin-1, and lower expression of p62. Accordingly, the apoptotic marker cleaved caspase-3 expression was markedly reduced following Empagliflozin treatment. Importantly, Empagliflozin did not alter the cytotoxic effect of Carfilzomib on human U266B1 myeloma cell line. Conclusion: This research suggests Empagliflozin could offer cardioprotection against Carfilzomib-induced cardiotoxicity in multiple myeloma patients.
Abstract Mo135: Correlation of Leptin Resistance With Attenuation of Cardiac Vagal Activation in Type 2 Diabetes
Authors: Anthony Evans, Huiyin Tu, Lauren Whitney, Kassidy Carpenter, Yulong Li
Journal: Circulation Research (2024)

Type 2 diabetes mellitus (T2DM) is one of the most prominent diseases impacting individuals worldwide. A leading cause of death for T2DM patients is MI-related ventricular arrhythmia, which is associated with cardiac vagal nerve dysfunction. As T2DM patients exhibit leptin resistance, and leptin signaling has been implicated in heart rate regulation, we set out to characterize changes in cardiac vagal ganglionic neuron activity during development of T2DM and determine leptin signaling’s role in cardiac vagal dysfunction. In this study, T2DM was induced in Sprague-Dawley rats by feeding a high fat diet (HFD) plus a low dose streptozotocin injection. To characterize cardiac dysfunction, we measured arterial baroreflex sensitivity and found that 12 wks post-T2DM induction, rats experienced a diminished baroreflex response (gain max 0.62 ± 0.04 bpm/mm Hg T2DM vs. 2.21 ± 0.14 bpm/mm Hg sham). To determine if the change in baroreflex sensitivity is due to altered cardiac vagal nerve activity, we measured nAChR currents and cell excitability in intracardiac ganglion (ICG) neurons and found that T2DM rat cardiac vagal neurons exhibited reduced nAChR current density (213.9 ± 25.6 pA/pF T2DM vs. 375.5 ± 44.3 pA/pF sham) and action potential frequency (9.1 ± 0.5 spikes/s T2DM vs. 19.9 ± 1.4 spikes/s sham). Furthermore, acetylcholine release from cardiac vagal nerve terminals was attenuated in T2DM rats (0.4 ± 0.16 nM T2DM vs. 1.07 ± 0.12 nM sham). To determine the role of leptin signaling in the decrease of cardiac vagal nerve activity, we examined leptin and leptin receptor levels in ICG at 4, 8, and 12 wks post-T2DM induction. Western blots revealed elevated ICG leptin levels at 4, 8, and 12 wks post-T2DM induction (8.9 ± 0.7, 9.1 ± 1.3, and 11.7 ± 2.1 times sham level, respectively). qRT-PCR revealed reduced levels of leptin receptor transcript at 12 wks post-T2DM induction (48 ± 12% of sham). A reduction of leptin receptor protein in ICG neurons at 12 wks post-T2DM induction was observed using IF microscopy. These data demonstrate that T2DM reduces cardiac vagal nerve activity resulting in diminished control of cardiac functions such as the baroreflex. Furthermore, leptin resistance may play a role in this diminished cardiac function through reductions in leptin receptor levels.
Abstract Mo002: Pharmacological Inhibition of p38 MAPK Attenuates Doxorubicin-induced Cardiotoxicity, Senescence, and Inflammation in C57BL/6 mice
Authors: Mohamed Dabour, Ibrahim Abdelgawad, bushra sadaf, MARY RAPHEL DANIEL, Marianne Grant, Beshay Zordoky
Journal: Circulation Research (2024)

Introduction: Doxorubicin (DOX)-induced cardiotoxicity has been associated with induction of senescence, inflammation, and activation of the p38 mitogen-activated protein kinase (MAPK) pathway. Losmapimod (LOSM), an orally active p38 MAPK inhibitor, is an anti-inflammatory agent with cardioprotective effects. Nevertheless, the effect of LOSM against DOX-induced cardiotoxicity has not been reported. The objective of the current work is to determine the effects of LOSM on DOX-induced chronic cardiotoxicity in C57BL/6 mice with particular focus on senescence and inflammatory pathways. Methods: Five-week-old C57BL/6 mice were fed diet containing LOSM (estimated daily intake 12 mg/kg/day) or a control diet for four days. Thereafter, mice were randomized to receive six weekly intraperitoneal injections of either DOX (4 mg/kg/week for 6 weeks) or saline. Three days after the last injection, cardiac function was assessed by trans-thoracic echocardiography. Gene expressions of senescence and inflammatory markers were quantified using real-time PCR and serum inflammatory markers were assessed by Luminex. Results: LOSM ameliorated DOX-induced cardiac dysfunction as evidenced by mitigated DOX-induced reduction in left ventricular fraction and fractional shortening. Notably, LOSM attenuating DOX-induced upregulation of p21 Cip1 , a marker of senescence, in the heart and the liver. Additionally, LOSM demonstrated anti-inflammatory effects, with reduced cardiac interleukin-1α and interleuken-6 gene expression in DOX-treated mice suggesting a senomorphic effect of LOSM. Systemic inflammation, assessed by serum cytokine levels, showed decreased interleukin-6 concentration in both DOX-treated mice and LOSM-treated mice. Conclusion: This is the first study to determine the effect of pharmacological inhibition of p38 MAPK against DOX-induced cardiotoxicity in vivo. Our study underscores the potential therapeutic efficacy of p38 MAPK inhibition in ameliorating DOX-induced cardiotoxicity, offering insights into novel strategies for mitigating chemotherapy-related cardiac complications, and suggesting a possible senomorphic effects of losmapimod.
Abstract Mo124: New Rho-kinase Inhibitor Reduces Diastolic Dysfunction induced by Estrogen Depletion in Spontaneously Hypertensive Rats
Authors: Gisele Zapata-Sudo, Juliana Carvalho, Tadeu Montagnoli, Bruno Dematte, Bruna Rocha, Rebeca Cunha, Heber Tolomeu, Carlos Fraga
Journal: Circulation Research (2024)

Heart failure with preserved ejection fraction (HFpEF) observed in women with estrogen depletion is a consequence of the reduction of cardioprotection and endothelial dysfunction. Rho-kinase (ROCK) signaling pathway plays a role in cardiac dysfunction consequent to female aging. This work investigated the effects of a new synthetic ROCK inhibitor (iROCK) after oral administration in spontaneously hypertensive rats (SHR) submitted to oophorectomy (OVX). Experimental protocols were approved Animal Care and Use Committee at Universidade Federal do Rio de Janeiro. Under ketamine (80 mg/kg, i.p.) and xylazine (15 mg/kg, i.p.) anesthesia, female SHR submitted to OVX had cardiac function assessed after 8 weeks and compared to SHR-Sham. Eight weeks after OVX, SHR were randomly divided in groups, which were orally treated with either vehicle (DMSO) or iROCK (10 mg/kg) during 2 weeks. Novel iROCK displays potent inhibitory activity for ROCK1 and ROCK2 isoforms, with IC50 of 1.3 μM and 1.7 μM, respectively. At the end of treatment, hemodynamic parameters were evaluated using echocardiography and LV catheterization. Cardiac tissues collected for determining the expression of mitogen-activated protein kinases p38MAPK and extracellular signal-regulated kinase (ERK-1/2) using Western blot technique. After 8 weeks of estrogen depletion, SHR displayed HFpEF because ejection fraction (EF) was 85.2 ± 0.9%, while a reduction in EF from 83.0 ± 2.7 to 64.9 ± 0.9% was only detected after 12 weeks of OVX. Altered filling pressure confirmed the diastolic dysfunction after OVX, because the ratio of rapid mitral flow (E) to rapid wave of mitral annulus tissue Doppler (e') increased from 12.1 ± 1.3 in SHR-Sham to 19.3 ± 0.5. LV end diastolic pressure (LVEDP) increased from 13.4 ± 1.3 to 21.1 ± 4.9 in SHR after 8 weeks post-OVX. Oral administration of iROCK (10 mg/kg) reduced both E/e’ to 16.2 ± 0.5 and LVEDP to 6.4 ± 0.7 mmHg. OVX in SHR increased cardiac p38 MAPK and ERK-1/2 contents by 2.3 and 1.3 fold from SHR-Sham values. In contrast, iROCK reduced p38 overexpression but not altered ERK-1/2 content. Since pro-inflammatory cytokines and oxidative stress activate p38, the recovery of its expression after treatment, indicates that iROCK could reduce the inflammatory component of HF. In conclusion, the new iROCK recovered LV diastolic function induced by estrogen depletion in SHR, through the reduction of myocardial inflammation.
Abstract Mo016: Atrial Fibrillation Outcomes in Carcinoid Tumor: A National Inpatient Sample (NIS) Study (2018-2020)
Authors: Mrunanjali Gaddam, Dhairya Nanavaty, Sujana Sanka, Priya Thanneeru, Rabia Iqbal, Jayalekshmi Jayakumar, Manasa Ginjupalli, Sowmya Baddula, Sarath Reddy
Journal: Circulation Research (2024)

Background: Carcinoid Tumor (CT) is a rare type of neuroendocrine tumor with a slow-growing nature. CT can affect different parts of the body, but it most commonly affects the gastrointestinal tract or the lungs. The average age of onset is in the early 60s, affecting around 1.5-1.9 people per 100,000 population. Atrial fibrillation (AF) has been associated with CT, however there is limited data about the outcomes associated with AF in the CT population. We aim to assess the impact of AF on mortality and complications in this population. Methods: The National Inpatient Sample database from 2018 to 2020 was analyzed to identify adult hospitalizations (age &gt; 18) with a diagnosis of CT using appropriate ICD 10 codes. This population was stratified based on concomitant AF. Demographics and complication rates including venous thromboembolic diseases (VTE), acute heart failure (AHF) and acute ischemic stroke (AIS) were studied in these cohorts using a chi-square test for categorical and a t-test for continuous variables. Multivariate regression analysis was further performed to study the impact of AF on complications and mortality after adjusting for relevant confounders. Results: A total of 70504 adult hospitalizations with CT were identified of which 12.71% (N=8964) had AF. 54% of CT admissions were females and the mean age was 64 years. Hospitalizations with CT and AF had a higher rate of VTE, AHF and AIS (Table 1). Multivariate regression analysis revealed higher odds of AHF and AIS with AF in the subpopulation of adults with CT, while the odds of VTE were statistically insignificant. The odds of mortality with AF were also significantly higher in this subpopulation (Table 2). Conclusion: Our study concludes that atrial fibrillation portends a worse prognosis in hospitalizations with Carcinoid Tumor. It also shows a higher rate of AHF and AIS in this subgroup with statistically significant odds. Further studies should be done to study the impact of atrial fibrillation in Carcinoid Tumor patients and treatment guidelines for better management of atrial fibrillation in this vulnerable cohort should be formulated to improve patient outcomes.
Abstract Mo026: ATP-dependent citrate lyase Drives Left Ventricular Dysfunction by Metabolic Remodeling of the Heart
Authors: Shijie Liu, Yaqi Gao, Kyoungmin Kim, Seth Gammon, Lin Tan, Janet Pham, Radhika Khanna, Benjamin Gould, Rebecca Salazar, Evan Lien, Blake Hanson, Matthew Vander Heiden, Philip Lorenzi, Heinrich Taegtmeyer, David Piwnica-Worms, James Martin, Anja Karlstaedt
Journal: Circulation Research (2024)

Background: Metabolic remodeling is a hallmark of the failing heart. Oncometabolic stress during cancer increases the activity and abundance of the ATP-dependent citrate lyase (ACL, Acly ), which promotes histone acetylation and cardiac adaptation. ACL is critical for the de novo synthesis of lipids, but how these metabolic alterations contribute to cardiac structural and functional changes remains unclear. Methods: We utilized MyH6-Cas9 mice (male and female) and CRISPR/Cas9 gene editing to generate a cardiac-specific Acly knockdown (AclyKD) mouse model. To assess how the loss of Acly impacts cardiac energy substrate metabolism, we conducted positron emission tomography in vivo and ex vivo stable isotope tracer labelling using working heart preparation. We conducted a multi-omics analysis using RNA-sequencing and mass spectrometry-based metabolomics. Experimental data were integrated into computational modelling using the metabolic network CardioNet to identify significantly dysregulated metabolic processes at a systems level. Results: Loss of ACL expression causes a left-ventricular cardiomyopathy by histology and echocardiography. FDG-PET/CT imaging in male and female mice demonstrated an increased glucose uptake and utilization in AclyKD mice, suggesting a substrate switch from fatty acid oxidation towards glucose. These findings were corroborated by stable isotope tracing, demonstrating that AclyKD suppresses fatty acid oxidation while enhancing lipid remodelling. AclyKD also reduced the efflux of glucose-derived citrate from the mitochondria into the cytosol, confirming that citrate is required for reductive metabolism in the heart. Computational flux analysis and integrative multi-omics analysis indicate that ACL activity supports lipid biosynthesis in the heart. Blocking mitochondrial isocitrate dehydrogenase or alpha-ketoglutarate dehydrogenase sensitized cardiomyocytes to ACL inhibition, and overexpressing cytosolic isocitrate dehydrogenase was sufficient to prevent citrate accumulation. Conclusions: Our work demonstrates a previously undescribed function of ACL as a regulator of cardiac energy substrate metabolism and lipid modulation.
Abstract Mo014: Cardioactive molecules identified by functional in vivo screening prevent anthracycline cardiotoxicity
Authors: Francesca Bortolotti, Antonio Mura, Matteo Maria Riccio, Matteo Dal Ferro, Lorena Zentilin, Mauro Giacca
Journal: Circulation Research (2024)

Introduction: Promotion of cardiomyocyte survival upon insult is mandatory to allow maintenance of ventricular function and dam development of severe heart dysfunction. Recently, through an in vivo functional screening of the mouse secretome we identified potent mediators of cardiomyocyte survival among 1200 soluble factors expressed by AAV vectors. The cardiac overexpression of the most effective cytokines (Chrdl1, Fam3c and Fam3b) maintained cardiac function after myocardial infarction by blunting oxidative damage, decreasing cell death, promoting autophagy, and inhibiting myofibroblast activation (Ruozi, Bortolotti et al. 2022. Sci Transl Med 14, eabo0699) Aim: We investigated the effect of cardioactive proteins in a mouse anthracycline model of cardiotoxicity. Material and Methods: Mimicking clinical chronic therapeutic regimens, doxorubicin (24 mg/kg) was administered to C57/BL6 female mice one week after AAV9-driven cardiac overexpression of Chrdl1, Fam3b or Fam3c. Echocardiography was performed after 6 and 8 weeks and was followed by histology and molecular analysis. Apoptosis, autophagy and mitochondrial function was analysed in primary cardiomyocytes along with pathway investigation. Results: AAV9-mediated overexpression of Chrdl1, Fam3b and Fam3c markedly improved animal survival. Echocardiographic assessment revealed significant reduction of left ventricular ejection fraction and marked heart dilatation in control animals, while all treated animals maintained functional and anatomical parameters. Treated mice showed normal cardiac mass and cardiomyocyte cross-sectional area, reduced interstitial collagen deposition and decreased expression of profibrotic genes. In both rodents and human cardiomyocytes, Chrdl1, Fam3b and Fam3c factors decreased doxorubicin induced apoptosis, induced protective macroautophagy and preserved mitochondrial morphology. Chrdl1 prevented doxorubicin-mediated BMP upregulation and autophagy engulfment through the inhibition of a detrimental molecular pathway downstream the BMP receptor. Conclusions: The development of biotherapeutics that act as pro-survival factors for cardiomyocytes offers significant translational perspectives in cardio-oncology.