tbuckley/cabot-search huggingface dataset:
Abstract Mo007: Molecular Basis of Sepsis-Induced Cardiomyopathy Under Anthracycline Treatment: Insights from Mouse Model
Authors: Kasturi Markandran, Rina Wang, Yi Peng Lim, Ching Kit Chen
Journal: Circulation Research (2024)

Anthracyclines constitute a fundamental component in numerous paediatric chemotherapy regimens. However, its myelosuppressive &amp; cardiotoxic nature put patients at risk of sepsis and sepsis-induced cardiomyopathy (SIC). When anthracycline-treated patients develop SIC, successful treatment of sepsis is sufficient for the restoration of cardiac function, giving rise to the 'transient cardiac dysfunction' phenomenon. Although transient it poses compromised clinical outcomes &amp; the mechanism driving this phenomenon remains elusive. We hypothesise that the molecular regulators of the phenomenon lie within cardiac cell populations &amp; is controlled by transcriptional activation. Thus, we aim to model 'transient cardiac dysfunction' in mice and conduct transcriptomics on their heart tissues. ‘Transient cardiac dysfunction’ was modelled in male juvenile C57BL6 mice treated with a cumulative of 10mg/kg doxorubicin followed by sepsis induction via cecal ligation &amp; perforation (CLP) to induce SIC. To recapitulate ‘transient cardiac dysfunction’, antibiotics were administered 20h post-CLP to treat sepsis &amp; restore cardiac function. Controls against doxorubicin (saline treatment) was established. Echocardiography and biological sample curation were conducted at pre-SIC (before CLP), onset-SIC (10h post-CLP) &amp; post-SIC (60h post-CLP). Sepsis was verified based on procalcitonin fold change as compared to pre-SIC (n=3-6). Procalcitonin was 15±1.6 folds higher in dox- (n=3) &amp; 10±0.39 folds higher in saline-treated (n=3) mice at onset-SIC. The infection was more aggressive in dox-treated mice as procalcitonin remained elevated at post-SIC (17.1±2.0, n=4), whereas in saline-treated mice, procalcitonin was reduced by post-SIC (7.9±1.0, n=3). In saline-treated mice, LVEF(%) was reduced at onset-SIC (49.0%±3.0, n=7) from pre-SIC (58.1±1.1, n=7) and recovered to baseline by post-SIC (61.8±1.7, n=5). In the contrary, LVEF in dox-treated mice (n=7) was increased at onset-SIC (62.5±1.7) from pre-SIC (56.0±0.8) &amp; sustained till post-SIC (60.1±1.0), suggesting cardioprotection. Normal distribution was verified before statistical hypothesis testing. In conclusion, ‘transient cardiac dysfunction’ was modelled in saline-treated mice, &amp; novel cardio protective effect was observed in dox-treated mice. Moving forward, longitudinal snRNA-seq will be conducted on whole hearts to identify cardiac cell populations &amp; genes responsible for ‘transient cardiac dysfunction’ &amp; cardioprotection.
Abstract Mo022: Doxorubicin induces cardiomyopathy through Wnt5a-mediated induction of senescence
Authors: Eun-Ah Sung, Junichi Sadoshima
Journal: Circulation Research (2024)

Doxorubicin (DOX) is a chemotherapeutic agent used to treat cancer, but its clinical use is restricted due to cardiotoxicity. Senescence is defined by resistance to apoptosis and a senescence-associated secretory phenotype (SASP). Elimination of senescent cells can improve cardiac dysfunction, suggesting that senescent cardiomyocytes (CMs) contribute to impaired heart function. Although DOX induces senescence in CMs, little is known about the mechanisms mediating DOX-induced senescence and cardiomyopathy. Wnt5a, a non-canonical Wnt ligand, is an important player in cardiac diseases and is upregulated in induced pluripotent stem cell (iPSC)-derived CMs from patients with heart failure induced by DOX chemotherapy. However, the role of Wnt5a in mediating DOX-induced cardiomyopathy remains elusive. Wnt5a protein expression was increased (4.4-fold, p&lt;0.001) in mouse hearts with DOX-induced cardiomyopathy. Upregulation of Wnt5a following DOX treatment was also observed in neonatal rat CMs (NRCMs), and the degree of upregulation was more prominent in CMs (2.1-fold) than in non-CMs (1.1-fold). In NRCMs, Wnt5a induced senescent phenotypes, including increases in the p16 protein level, the number of γH2AX foci per cell and SA-β-gal activity. Wnt5a knockdown reduced DOX-induced increases in the p16 protein level in NRCMs, suggesting that Wnt5a mediates DOX-induced CM senescence. To assess the role of endogenous CM Wnt5a in mediating DOX-induced cardiomyopathy, we generated Myh6 -cre Wnt5a fl/fl ( Wnt5a cKO ) mice, in which Wnt5a is knocked out in a CM-specific manner. DOX-treated Wnt5a cKO mice showed little difference in ejection fraction (EF) compared to PBS-treated Wnt5a cKO mice (56.64 ± 6.17% and 57.60 ± 5.23%), while DOX-treated Wnt5a fl/fl mice showed a significant decrease in EF (34.63 ± 3.65%, p&lt;0.0001). These results suggest that Wnt5a deletion in CMs impedes the progression of DOX-induced cardiac dysfunction, positioning Wnt5a as a novel therapeutic target for the prevention of DOX-induced cardiomyopathy.
Abstract Mo140: Macrophage Piezo1 exacerbates cardiac dysfunction through inhibiting clearance of apoptotic cardiomyocytes after myocardial infarction
Authors: Lu Peng, zhen Guo, xue han, Shiyue Wang, Zhaoyi Luo, Yunlong Xia, huilan Tan, Xiaoming Xu, quanchi liu, Fengyue Ding, Huishou Zhao, Yajing Wang, Ling Tao, Wenjun Yan
Journal: Circulation Research (2024)

Background: Phagocytic clearance of dying cells by efferocytosis is pivotal for the inflammation resolution and heart repair after myocardial infarction (MI). Macrophages are considered key phagocytes involved in efferocytosis, however, the molecular mechanisms underlying macrophage efferocytosis during MI remain vastly unknown. Here, we aimed to identify the role of mechanosensor Piezo1 in macrophage efferocytosis during MI. Methods: Myeloid cell-specific Piezo1 deficient mice (Piezo1 ΔLyz2 ) and their littermate controls (Piezo1 fl/fl ) underwent MI or sham operation to investigate whether Piezo1 in macrophages plays a functional role during ventricular remodeling. Bone marrow-derived macrophages (BMDMs) and peritoneal macrophages (PMs) were utilized to perform efferocytosis assays with or without Piezo1 activator Yoda1. RNA sequencing (RNA-seq) analysis was used to explore the possible molecular mechanisms. Results: Piezo1 expression was significantly increased in BMDMs isolated from mice 3 days after MI compared to sham groups. Moreover, double immunofluorescent staining indicated that Piezo1 was more likely to colocalize with macrophages in the infarcted area 1 week post-MI. Piezo1 ΔLyz2 mice exhibited significant ameliorations in left ventricular remodeling and function after MI, accompanied with the less accumulation of apoptotic cardiomyocytes and an increased index of in vivo efferocytosis in the border area. We also found the enhanced uptake of apoptotic cells by Piezo1 ΔLyz2 mice derived BMDMs compared with Piezo1 fl/fl control. Furthermore, Piezo1 activation by Yoda1 induced defective efferocytosis in BMDMs and PMs. RNA-seq analysis revealed that Yoda1 significantly increased the mRNA level of solute carrier family 7a member 11 (SLC7A11), a negative regulator of efferocytosis. SLC7A11 knockdown in BMDMs by siRNA effectively restored the defective efferocytosis induced by Piezo1 activation. Finally, we identified that Piezo1 activation induced SLC7A11 upregulation in macrophage through a Ca 2+ /ATF4 dependent manner. Conclusions: Taken together, our results demonstrated a novel mechanism by which Piezo1 activation impairs macrophage efferocytosis ability and results in excessive cardiomyocyte death after MI, providing a previously unknown insight into Piezo1-mediated mechanotransduction in the regulation of macrophage efferocytosis.
Abstract Mo017: CXCR3: A Tumor-Conscious Target to Treat Immunotherapy-Induced Myocarditis
Authors: Yin Sun, Yuhsin Huang, Harrison Chou, Maria Rosaria Vitale, Zachary Lin, Han Zhu
Journal: Circulation Research (2024)

Introduction: Immune checkpoint inhibitors (ICIs, such as anti-CTLA-4 or anti-PD-1) have especially been effective in cancer therapies. However, ICIs treatment can result in myocarditis, the most serious complication of ICIs, which has a case fatality rate as high as 40%. Here, we investigate CXCR3 blockade for targeted treatment of myocardial inflammation in ICI myocarditis while considering concurrent tumor treatment. We hypothesize that CXCR3 blockade will have a direct effect on reducing CD8+ T-cell mediated cardiomyocyte cardiotoxicity without affecting tumor treatment. Methods: To study the impact of CXCR3 blockade on myocardial inflammation, we established an in vitro cardiomyocyte apoptosis model by co-culturing cardiomyocytes and MRL-WT mice CD8+ T-cells with/without ICI stimulation or MRL- Pdcd1-/- mice CD8+ T-cells. We then blocked CXCR3 to assess the effect on CD8+ T cell-mediated cytotoxicity against cardiomyocytes. To assess CXCR3 blockade in an in vivo model of ICI myocarditis accounting for tumor, we treated MRL mice inoculated with B16F1 melanoma cells with six doses of 400 µ g each of anti-PD1 and anti-CTLA4 and investigated the effects of CXCR3-CXCL9/10 blockade on hearts and tumors. Results: In vitro CD8+ T-cell and cardiomyocyte co-culture demonstrated mitigation of cardiomyocytes apoptosis with CXCR3 blockade ( Fig. 1 A - C) , suggesting decreased CD8+ T-cell cytotoxicity with CXCR3 blockade. In vivo treatment with dual immunotherapy (anti-PD1/anti-CTLA4 monoclonal antibodies) in the tumor MRL mouse model demonstrated significant tumor volume reduction, which was not impacted by concurrent treatment with anti-CXCR3 or anti-CXCL9/10 (Fig. 1 D - F) . Concurrently, myocarditis occurred in the group treated with immunotherapy alone, not in anti-CXCL9/10 or anti-CXCR3 (Fig. 1 G - H). Conclusions: CXCR3 blockade reduces CD8+ T-cell cytotoxicity against cardiomyocytes and mitigates myocarditis in an in vivo tumor ICI myocarditis mouse model without affecting anti-tumor ICI efficacy, positioning CXCR3 as a promising target for therapeutic intervention.
Abstract Mo013: Regulation of Ferroptosis by Wnt5a in the Heart: Implication in Cardio-Oncology
Authors: Nadezhda Fefelova, Eun-Ah Sung, Sri Harika Pamarthi, Chanon Piamsiri, Judith Gwathmey, Junichi Sadoshima, Lai-Hua Xie
Journal: Circulation Research (2024)

Ferroptosis is an iron and lipid peroxidation dependent form of cell death. It has been implicated in ischemia/reperfusion injury, heart failure, and doxorubicin (Dox)-induced cardiotoxicity (DIC). While Wingless-type family member (Wnt) pathways are crucial for heart development and remodeling, the role of Wnt5a in regulating ferroptosis in cardiac cells and its relevance to DIC remain unclear. In the present study, we investigate the role of Wnt5a signaling in cardiac ferroptosis and its implication in cardio-oncology. We observed an increase in Wnt5a secretion in H9C2 cardiac cells upon treatment with ferroptosis inducers such as ferric ammonium citrate (FAC 2 mM) and RSL3 (20 nM). Live/Dead viability analyses in cultured mouse cardiomyocytes (CMs) and cardiac fibroblasts (CFs) revealed that the Wnt5a antagonist BOX5 (100 µM) attenuated ferroptosis induced by FAC or RSL3 in both CMs and CFs. Similarly, FAC- and RSL3-induced ferroptotic death rates were reduced in CMs from Wnt5a conditional knockout (cKO) mice. Recombinant Wnt5a (rWnt5a) induced CM death in a dose-dependent manner (5, 7, 10 µg/ml) and was partially prevented by Fer-1 (10 µM), a selective ferroptosis inhibitor. Moreover, rWnt5a (10 µg/ml) also effectively induced CF ferroptosis which was inhibited by Fer-1. rWnt5a and its mimicking peptide Foxy5 also modulated the sensitivity to various ferroptosis inducers. Furthermore, FAC-, RSL3- and rWnt5a-induced ferroptosis were attenuated in CMs from frizzled 2 receptor cKO mice. We further delineated the role of Wnt5a upregulation in Dox-induced ferroptosis and the development of DIC. In a chronic DIC mouse model, Wnt5a upregulation in the heart correlated with left ventricular dysfunction which was abrogated in Wnt5a cKO mice. Live/Dead viability analyses showed that Dox induced ferroptosis which was partially prevented by Fer-1 in CMs. Inhibition of the Wnt5a pathway by BOX5 led to a decrease in the rate of Dox-induced ferroptosis, while the sensitivity to ferroptosis was enhanced by rWnt5a. Our study has shown for the first time that the production and secretion of Wnt5a in an autocrine and/or paracrine manner promotes ferroptosis in CMs and CFs. Wnt5a is likely to be a critical mediator of Dox-induced ferroptosis and cardiotoxicity.
Abstract Or121: Druggable Genome CRISPRi/a Screens in iPSC-Derived Cardiomyocytes Identify Therapeutic Targets for Doxorubicin-Induced Cardiotoxicity
Authors: Chun Liu, Mengcheng Shen, Amit Manhas, Shane Zhao, Nadjet Belbachir, Masataka Nishiga, Dilip Thomas, Angela Zhang, Mao Zhang, Joe Zhang, Arianne Caudal, Huaxiao Yang, Nazish Sayed, June Rhee, Stanley Qi, Joseph Wu
Journal: Circulation Research (2024)

Introduction: Doxorubicin is a highly effective chemotherapy drug whose therapeutic utility is significantly hampered by its life-threatening adverse cardiac effects. The need for strategies to mitigate these cardiotoxic effects without diminishing its efficacy against cancer is critical in cardio-oncology. Hypothesis: We hypothesize that through an integrated drug discovery pipeline, utilizing patient iPSC-derived cardiomyocytes (iCMs) and CRISPRi/a bidirectional pooled screens combined with small molecule screening and molecular docking, we can identify therapeutic targets that ameliorate doxorubicin-induced cardiotoxicity (DIC) while preserving its anticancer efficacy. Methods: Our approach included patient iPSC-derived cardiomyocytes (iCMs), CRISPRi/a bidirectional pooled screens targeting druggable genome (~2000 genes) to identify candidate genes implicated in DIC, and small molecule screening alongside molecular docking to find potential inhibitors. Notably, carbonic anhydrase 12 (CA12) was identified as a primary hit for its role in DIC. Results: The CRISPRi/a screens revealed several novel genes, including CA12, as potential contributors to DIC. Genetic inhibition of CA12 in iCMs enhanced cell survival, preserved sarcomere structure, and improved contractile function and calcium handling, effectively protecting against DIC. Furthermore, we discovered that a CA12 antagonist significantly attenuates DIC in both iCMs and mouse models. Mechanistic studies suggested that doxorubicin triggers CA12 activation, leading to a metabolic change towards glycolysis in cardiomyocytes, thereby exacerbating DIC by disrupting cellular metabolism and cardiac functions. Conclusions: Our findings propose a novel therapeutic avenue to safeguard against doxorubicin-induced cardiotoxicity through the targeting of CA12, offering new direction for the development of more refined anticancer therapies that minimize cardiotoxic risk. This study sets the stage of combining CRISPRi/a screen with iPSC technology for future drug discovery endeavors aimed at eliminating off-target cardiotoxicities of chemotherapy agents.
Abstract Mo008: Sub-strain Dependent Vulnerability to Psychosocial Stress Exacerbates Doxorubicin-induced Cardiotoxicity in Adult Male Mice
Authors: MARY RAPHEL DANIEL, Marianne Grant, Maria Razzoli, Alessandro Bartolomucci, Beshay Zordoky
Journal: Circulation Research (2024)

Introduction: Psychosocial stress is a significant cardiovascular risk factor and an enormous burden on cancer patients. However, limited knowledge is available on the underlying mechanisms at least in part because of lack of translationally relevant animal models. Previous work from our lab established that adult exposure to social stress can exacerbate the cardiovascular effect of juvenile doxorubicin (DOX) exposure. However, the effect of concomitant DOX and stress exposure in adult mice is unknown. Methods: In this study, a ‘two-hit’ mouse model was established, in which chronic subordination stress (CSS) and DOX treatment were given simultaneously. Twelve-week-old male C57BL/6N (6N) and C57BL/6J (6J) mice were subjected to daily episodes of social defeat by dominant CD1 mice with whom they remained in continuous sensory contact with for 28 days, thus establishing social subordination. One week after the start of CSS, mice were administered DOX (8 mg/kg/week) for 3 weeks. Thereafter, cardiac function was assessed by echocardiography and gene expression of inflammatory and pro-fibrotic markers were determined by real-time PCR. Cardiac fibrosis and inflammation were assessed by histopathologic analysis. Results: Cardiac dysfunction and significant cardiac fibrosis were observed in 6N but not in 6J mice that were exposed to both DOX and CSS, as evidenced by reduced ejection fraction, cardiac output, and increased trichrome staining, respectively. Additionally, gene expression analysis demonstrated significant upregulation of atrial natriuretic peptide and interleukin-6 in 6N mice exposed to both DOX and CSS compared to 6J mice. Finally, DOX caused cardiac atrophy and abrogated CSS-induced cardiac hypertrophy in 6N but not in 6J mice, as evidenced by measuring left ventricular mass and heart weight/tibia length. Conclusion: Exposure to CSS exacerbated the cardiotoxic effects of DOX in a sub-strain dependent manner. These findings highlight psychosocial stress as a risk factor for worse cardiovascular outcome in cancer patients receiving cardiotoxic regimens. The study underscores sub-strain differences in the cardiac responses of 6N and 6J mouse to CSS alone and CSS/DOX treatment that may serve as a discovery platform for the identification of genetic biomarkers of resilience.
Abstract Mo023: Inhibition of Cyp1a Protects Mice against Anthracycline Cardiomyopathy
Authors: Jing Liu, Casie Curtin, Abul Ariza, Jakob Wieke, Leinal Sejour, Ioannis Vlachos, Aarti Asnani
Journal: Circulation Research (2024)

Background: Anthracyclines such as doxorubicin (Dox) are highly effective anti-tumor agents, but their use is limited by dose-dependent cardiomyopathy. Our laboratory previously reported that activation of cytochrome P450 family 1 (Cyp1) enzymes contributes to acute doxorubicin (Dox) cardiotoxicity in zebrafish and in mice, and that potent Cyp1 inhibitors prevent cardiotoxicity. However, the role of Cyp1 enzymes in chronic Dox cardiomyopathy, as well as the mechanisms underlying cardioprotection associated with Cyp1 inhibition, have not been fully elucidated. Objective: This study aims to define the role of Cyp1 inhibition in mouse models that more accurately recapitulates the chronic cardiomyopathy seen in patients. Methods: The function of Cyp1 enzymes was evaluated using a small molecule Cyp1 inhibitor in wild-type (WT) mice, or Cyp1-null mice ( Cyp1a1/1a2 -/- , Cyp1b1 -/- , and Cyp1a1/1a2/1b1 -/- ). Low-dose Dox was administered by serial intraperitoneal or intravenous injections, respectively. Expression of Cyp1 isoforms was measured by RT-qPCR, and myocardial tissue was isolated from the left ventricle for RNA sequencing. Cardiac function was evaluated by transthoracic echocardiography. Results: In WT mice, Dox treatment was associated with a decrease in Cyp1a2 and an increase in Cyp1b1 expression in the heart and in the liver. Co-treatment of WT mice with Dox and the potent Cyp1 inhibitor YW-130 protected against cardiac dysfunction compared to Dox treatment alone. Cyp1a1/1a2 -/- and Cyp1a1/1a2/1b1 -/- mice were protected from Dox cardiomyopathy compared to WT mice. Male, but not female, Cyp1b1 -/- mice had increased cardiac dysfunction following Dox treatment compared to WT mice. RNA sequencing of myocardial tissue showed upregulation of Fundc1 and downregulation of Ccl21c in Cyp1a1/1a2 -/- mice treated with Dox, implicating changes in mitophagy and chemokine-mediated inflammation as possible mechanisms of Cyp1a-mediated cardioprotection. Conclusions: Taken together, this study highlights the potential therapeutic value of Cyp1a inhibition in mitigating anthracycline cardiomyopathy.
Abstract Mo131: Time-Restricted Feeding Normalizes Dim Light at Night-Induced Disruption of Cardiovascular Rhythms in Mice
Authors: Abhilash Prabhat, Dema Sami, Allison Ehlman, Rebecca Stalcup, Tanya Seward, Wen Su, Ming Gong, Elizabeth Schroder, Brian Delisle
Journal: Circulation Research (2024)

Background: Light input to the suprachiasmatic nucleus entrains circadian rhythms in physiology and behavior to the day-night cycle. Exposure to light at night in people is associated with cardiometabolic disease. Pre-clinical studies show that artificial light at night, including at very low levels, disrupts day-night rhythms in activity, feeding behavior, heart rate, and blood pressure dipping. Hypothesis: Dim light at night (dLAN) disrupts day-night rhythms in feeding behavior to blunt day-night rhythms in autonomic input to the heart and blood pressure dipping. Methods: Mice (n=5-6/sex) in thermoneutral housing were implanted with telemetry probes to record heart rate, blood pressure, and core body temperature. Autonomic input to the heart was assessed by measuring heart rate and subtracting the temperature-dependent changes in the heart rate after pharmacological inhibition of muscarinic and β-adrenergic receptor activation. Mice were housed in 12 h light: 12 h dark cycles (LD, 200 lux: 0 lux) with ad libitum access to food (LD-ALF), subjected to 12 h light: 12 h dLAN cycles (dLAN-ALF; 200 lux: 5 lux) for two weeks, and then feeding was time-restricted (not calorically restricted) to the dLAN cycle (dLAN-RF). Data were extracted from Ponemah and Clocklab, and statistical analysis was done using GraphPad PRISM software. Results: Compared to LD-ALF mice, dLAN-ALF mice showed reduced amplitudes in day-night activity, feeding, heart rate, and blood pressure rhythms, with males more affected than females (p&lt;0.001). dLAN-ALF male and female mice had decreased amplitudes in the day-night rhythms in autonomic input to the heart. In addition, dLAN-ALF male mice had less blood pressure dipping. dLAN-RF normalized autonomic input to the heart and heart rate in male and female mice (p&lt;0.05, p&lt;0.01, respectively). dLAN-RF also improved blood pressure dipping in male mice (p&lt;0.001). dLAN-RF did not normalize activity rhythms. Conclusion: dLAN disrupts day-night rhythms in activity, feeding, heart rate, and blood pressure dipping in mice, with males being more impacted. Time-restricted feeding to the dLAN cycle normalizes autonomic input to the heart and blood pressure dipping. These data suggest that time-restricted feeding counteracts the light-at-night-induced circadian disruption of cardiovascular function.