Cancer therapy-related cardiovascular toxicity (CTR-CVT) is now recognised as one of the leading causes of long-term morbidity and mortality in cancer patients. To date, potential overlapping cardiotoxicity mechanism(s) across different chemotherapeutic classes have not been elucidated. Doxorubicin, an anthracycline, and Carfilzomib, a proteasome inhibitor, are both known to cause heart failure in some patients. Given this common cardiotoxic effect of these chemotherapies, we aimed to investigate differential and common mechanism(s) associated with Doxorubicin and Carfilzomib-induced cardiac dysfunction. Primary human cardiomyocyte-like cells (HCM-ls) were treated with 1 µM of either Doxorubicin or Carfilzomib for 72 h. Both Doxorubicin and Carfilzomib induced a significant reduction in HCM cell viability and cell damage. DNA methylation analysis performed using MethylationEPIC array showed distinct and common changes induced by Doxorubicin and Carfilzomib (10,270 or approximately 12.9% of the DMPs for either treatment overlapped). RNA-seq analyses identified 5,643 differentially expressed genes (DEGs) that were commonly dysregulated for both treatments. Pathway analysis revealed that the PI3K-Akt signalling pathway was the most significantly enriched pathway with common DEGs, shared between Doxorubicin and Carfilzomib. We identified that there are shared cardiotoxicity mechanisms for Doxorubicin and Carfilzomib pathways that can be potential therapeutic targets for treatments across 2 classes of anti-cancer agents.

Sex-based differences in the development of obesity-induced cardiometabolic dysfunction are well documented, however, the specific mechanisms are not completely understood. Obesity has been linked to dysregulation of the epitranscriptome, but the role of N6-methyladenosine (m6A) RNA methylation has not been investigated in relation to the sex differences during obesity-induced cardiac dysfunction. In the current study, male and female C57BL/6J mice were subjected to short- and long-term high-fat/high-sucrose (HFHS) diet to induce obesogenic stress. Cardiac echocardiography showed males developed systolic and diastolic dysfunction after 4 mo of diet, but females maintained normal cardiac function despite both sexes being metabolically dysfunctional. Cardiac m6A machinery gene expression was differentially regulated by duration of HFHS diet in male, but not female mice, and left ventricular ejection fraction correlated with RNA machinery gene levels in a sex- and age-dependent manner. RNA-sequencing of cardiac transcriptome revealed that females, but not males may undergo protective cardiac remodeling early in the course of obesogenic stress. Taken together, our study demonstrates for the first time that cardiac RNA methylation machinery genes are regulated early during obesogenic stress in a sex-dependent manner and may play a role in the sex differences observed in cardiometabolic dysfunction.NEW & NOTEWORTHY Sex differences in obesity-associated cardiomyopathy are well documented but incompletely understood. We show for the first time that RNA methylation machinery genes may be regulated in response to obesogenic diet in a sex- and age-dependent manner and levels may correspond to cardiac systolic function. Our cardiac RNA-seq analysis suggests female, but not male mice may be protected from cardiac dysfunction by a protective cardiac remodeling response early during obesogenic stress.

BACKGROUND:Increased cancer survivorship represents a remarkable achievement for modern medicine. Unfortunately, cancer treatments have inadvertently contributed to cardiovascular (CV) damage, significantly threatening the health and quality of life of patients living with, through and beyond cancer. Without understanding the mechanisms, including whether the cardiotoxicity is due to the direct or indirect effects on cardiomyocytes, prevention and management of cardiotoxicity can pose challenges in many patients. To date, the cardiotoxicity profiles of most of the chemotherapy drugs are still poorly understood.AIM:To conduct a pilot study to investigate the direct effects of a range of cancer therapies on cardiomyocyte viability.METHODS:Primary human cardiomyocytes (HCM) were cultured and seeded into 96-well culture plates. A total of 35 different Food and Drug Administration-approved anti-cancer drugs were added to the HCM cells with a concentration of 1uM for 72 hours. The viability of HCMs was determined using CellTitre-Glo. The experiments were repeated at least three times for each drug with HCMs of different passages.RESULTS:We identified 15 anti-cancer agents that significantly reduced HCM viability. These drugs were: (1) anthracyclines (daunorubicin [HCM viability, mean %±standard error, 13.7±3.2%], epirubicin [47.6±5.3%]), (2) antimetabolite (azacitidine [67.1±2.4%]), (3) taxanes (paclitaxel [60.2±3.0%]), (4) protein kinase inhibitors (lapatinib [49.8±7.0%], ponatinib [42.4±9.0%], pemigatinib [68.1±2.3%], sorafenib [52.9±10.6%], nilotinib [64.4±4.5%], dasatinib [38.5±3.6%]), (5) proteasome inhibitors (ixazomib citrate [65.4±7.2%]), (6) non-selective histone-deacetylase inhibitor (panobinostat [19.1±4.1%]), poly adenosine diphosphate-ribose polymerase inhibitor (olaparib [68.2±1.7%]) and (7) vinca alkaloids (vincristine [44.6±7.4%], vinblastine [31.2±3.9%]).CONCLUSIONS:In total, 15 of the 35 commercially available anti-cancer drugs have direct cardiotoxic effects on HCM. Some of those, have not been associated with clinical cardiotoxicity, while others, known to be cardiotoxic do not appear to mediate it via direct effects on cardiomyocytes. More detailed investigations of the effects of cancer therapies on various cardiovascular cells should be performed to comprehensively determine the mechanisms of cardiotoxicity.

As climate change abets severe conditions, bushfire smoke (BFS) exposure is becoming a major public health challenge and economic burden in Australia. Whilst BFS exposure has been linked with increased cardiovascular adverse events, the underlying mechanism remain poorly understood. This study aimed to investigate BFS exposure in 1) primary human cardiomyocyte (HCM) and 2) a highly representative animal model of BFS exposure. Human cardiomyocytes were incubated with either PBS or BFS for 72 hours. Cell viabilities (Cell Titre Glo) and mitochondria function (MitoSOX & Seahorse XF Cell Mito Stress Test) were assessed. Female, 7–8-week-old C57BL/6 mice were given either a human representative, mouse-normalised dose of 100 μg/m3 BFS or PBS intranasally daily for 3 days. Non-invasive echocardiography was performed to assess cardiac function. Gene expressions were assessed via qPCR in cardiac tissues. The BFS exposure reduced the viability of HCM in a dose-dependent manner. The HCMs also demonstrated increased mitochondrial reactive oxygen species production and impaired mitochondrial function: basal and maximal respiration, spare respiratory capacity, and ATP-related oxygen consumption were reduced. A decrease in left ventricular ejection fraction (∼10%), fractional shortening, and left ventricular wall thickness following BFS exposure was observed in mice. Key antioxidant-associated genes (Nrf2, Sod1, Sod2, Parp1, and Cat) were also concomitantly reduced. This study showed for the first time that short-term BFS exposure directly reduced HCM viability, increased oxidative stress, and impaired mitochondria function. Together with reduced cardiac antioxidants, these lead to cardiac dysfunction. Further investigation will determine the role of antioxidants in BFS-induced cardiac impairments.

Abstract Introduction Inhibition of poly (ADP-ribose) polymerase (PARP) has been shown to be cardioprotective in acute and chronic myocardial injury. Additionally, PARP inhibitor, Olaparib, is a clinically effective anti-cancer agent. Activation of PARP pathway has been suggested to be involved in cardiotoxicity arising from Doxorubicin (DOX, one of the most used anticancer drugs). It is thus, entirely possible that PARP inhibition could be a novel pathway to prevent DOX-induced cardiotoxicity (DIC). Purpose To determine the cardioprotective effects of Olaparib in preventing DOX-induced cardiotoxicity in in vitro and in vivo models. Methods In vitro: Human cardiomyocytes (HCMs) were treated with DOX at 1uM (EC50) +/- various doses (15.6nM, 1uM, 80uM, 100uM and 150uM) of Olaparib at 72hrs. Cell viability was assessed via CellTiter-Glo®. The mRNA expressions of treated HCMs were performed by qPCR. In vivo: Female C57BL/6 mice (6-8 weeks old) were administered: A) DOX at 5mg/kg/week for 6 weeks via IP injections, B) vehicle of 0.9% saline and 5% DMSO in PBS, C) Olaparib at 50mg/kg was administered 3 times/week, D) Olaparib at 50mg/kg was administered 3 times/week, followed by DOX treatments. Cardiac function was assessed by echocardiography at baseline and end of 6 weeks’ treatment. Results For the in vitro model, Doxorubicin induced marked reduction in HCMs cell viability. Concomitant Olaparib treatment at higher doses (80uM, 100uM, 150uM) significantly preserved DOX-induced cell viability after 72 hours of treatment. Molecular analysis in HCMs showed DOX-induced upregulation of mRNA gene expressions for apoptosis: Casp3, DNA damage: BBC3, and cardiac remodelling: TGF-β; all of which were reversed by Olaparib. In vivo: we found significant reduction of left ventricular function and increased ventricular wall thickness in DOX treated group after 6 weeks’ treatment compare to baseline [LVEF%: 52.4±1.3 vs.56.5±2.0, P=0.02; FS%:16.7±1.4 vs. 20.1±1.3, P=0.03; Total Wall thickness (mm):2.1±0.1 vs. 1.9±0.1, P<0.05]; whereas the mice pre-treated with Olaparib in combination with DOX showed preservation of cardiac functions between endpoint and baseline. Conclusion Olaparib protected HCMs against DIC and improved cardiac function in DIC mice model. Our findings indicate that Olaparib could provide cardioprotection in DOX-induced cardiotoxicity.

Secreted frizzled-related protein 5 (SFRP5) is a novel anti-inflammatory adipokine that may play a role in cardiovascular development and disease. However, there is yet to be a comprehensive investigation into whether circulating SFRP5 can be a biomarker for cardiac function. Plasma SFRP5 levels were measured via ELISA in 262 patients admitted to a cardiology unit. Plasma SFRP5 levels were significantly lower in patients with a history of heart failure (HF), coronary artery disease (CAD), and atrial fibrillation (AF; p = 0.001). In univariate analyses, SFRP5 levels were also significantly positively correlated with left ventricular ejection fraction (LVEF) (r = 0.52, p < 0.001) and negatively correlated with E/E' (r = -0.30, p < 0.001). Patients with HF, CAD, low LVEF, low triglycerides, high CRP, and high eGFR were associated with lower SFRP5 levels independent of age, BMI, or diabetes after multivariate analysis (overall model r = 0.729, SE = 0.638). Our results show that low plasma SFRP5 levels are independently associated with the presence of HF, CAD, and, importantly, impaired LV function. These results suggest a potential role of SFRP5 as a biomarker, as well as a mediator of cardiac dysfunction independent of obesity and metabolic regulation.

A debilitating result of colorectal cancer (CRC) is cachexia, involving fat/muscle wasting, leading to cardiac atrophy and heart failure. Adipose tissue (AT) undergoes extensive remodelling, including enhanced resting energy expenditure, inflammation, oxidative stress, and lipolysis that promote cardiac cachexia and predict overall survival in CRC patients. Here, we hypothesised that improving adipose tissue health by adipose-targeted overexpression of mitochondrial catalase (mCAT) can prevent cardiac cachexia and overall survival in an animal model of colitis-induced CRC. AdipoQ-mCAT transgenic (TG) mice were generated by crossing AdipoQ-Cre with floxed mCAT mice. Colitis-associated CRC was induced by the AOM/DSS protocol in TG and age-matched wild-type (WT) mice. Compared to WTs, TG mice had better survival rates (80% vs 32%; p=0.0053), gained more weight and had reduced tumour number and burden observed by endoscopy. Adipose expression of inflammatory (CD68, F4/80, TNFA) and cachectic (Ghrelin, UCP2) markers increased significantly in WT cancer-bearing mice, which was reversed in TG mice. Consistent with cardiac cachexia, WT cancer-bearing mice had reduced wall thickness and LV mass measured by echocardiography, and significant cardiac changes to remodelling (COL1A1, COL3A1), inflammation (C6, S100A8), cell growth (FSTL1, GDF11) and metabolism (PPARGC1A, RARRES1) related genes whereas these changes were reversed in TG cancer-bearing mice. Adipose-targeted mCAT overexpression reduced inflammatory and cachectic markers in AT. Compared to WTs, TG mice had improved survival, reduced tumour burden and attenuation of cardiac structural and gene expression changes associated with cardiac cachexia. Therefore, adipose tissue health may be important in CRC and associated CV disease.

Obesity is associated with significant metabolic co-morbidities, such as diabetes, hypertension, and dyslipidaemia, as well as a range of cardiovascular diseases, all of which lead to increased hospitalisations, morbidity, and mortality. Adipose tissue dysfunction caused by chronic nutrient stress can result in oxidative stress, mitochondrial dysfunction, inflammation, hypoxia, and insulin resistance. Thus, we hypothesised that reducing adipose tissue oxidative stress via adipose tissue-targeted overexpression of the antioxidant mitochondrial catalase (mCAT) may improve systemic metabolic function. We crossed mCAT (floxed) and Adipoq-Cre mice to generate mice overexpressing catalase with a mitochondrial targeting sequence predominantly in adipose tissue, designated AdipoQ-mCAT. Under normal diet conditions, the AdipoQ-mCAT transgenic mice demonstrated increased weight gain, adipocyte remodelling, and metabolic dysfunction compared to the wild-type mice. Under obesogenic dietary conditions (16 weeks of high fat/high sucrose feeding), the AdipoQ-mCAT mice did not result in incremental impairment of adipose structure and function but in fact, were protected from further metabolic impairment compared to the obese wild-type mice. While AdipoQ-mCAT overexpression was unable to improve systemic metabolic function per se, our results highlight the critical role of physiological H2O2 signalling in metabolism and adipose tissue function.

The role of soluble suppression of tumorigenicity (sST2) as a biomarker in predicting clinical outcomes in patients with cardiovascular diseases (CVD) has not been fully elucidated. In this study, we sought to determine the relationship between sST2 levels and any unplanned hospital readmissions due to a major adverse cardiovascular event (MACE) within 1 year of first admission. Patients (n = 250) admitted to the cardiology unit at John Hunter Hospital were recruited. Occurrences of MACE, defined as the composite of total death, myocardial infarction (MI), stroke, readmissions for heart failure (HF), or coronary revascularization, were recorded after 30, 90, 180, and 365 days of first admission. On univariate analysis, patients with atrial fibrillation (AF) and HF had significantly higher sST2 levels vs. those who did not. Increasing levels of sST2 by quartiles were significantly associated with AF, HF, older age, low hemoglobin, low eGFR, and high CRP levels. On multivariate analysis: high sST2 levels and diabetes remained as risk predictors of any MACE occurrence; an sST2 level in the highest quartile (Q4: >28.4 ng/mL) was independently associated with older age, use of beta-blockers, and number of MACE events within a 1 year period. In this patient cohort, elevated sST2 levels are associated with unplanned hospital admission due to MACE within 1 year, independent of the nature of the index cardiovascular admission.

Abstract Introduction Doxorubicin (DOX) is among the most used anticancer drugs with associated cardiotoxicity. Follistatin-like 3 (FSTL3), a secreted member of the follistatins family that can selectively bind to members of the TGF-β superfamily, is involved in regulation of cardiac hypertrophy and heart failure. FSTL3 is also upregulated in breast and colorectal cancer tumours, is also an unfavourable prognostic indicator for various cancers. Purpose We aim to determine the dual role of FSTL3 in prevention of DOX-induced cardiotoxicity and synergistic anti-cancer effects. Methods Human cardiomyocytes (HCMs) were treated with DOX at 1uM (EC50) for 72 hours. Cell viability was assessed via CellTiter-Glo®. Secreted FSTL3 levels, as measured by ELISA (R&D systems). FSTL3 and TGF-β mRNA levels were measured by qPCR. Co-treatment of DOX with human anti-FSTL3 antibodies (Aviva Systems Biology) at 10ug/mL were introduced for 72hrs treatment. Results Secreted FSTL3 levels were significantly increased in DOX-treated HCMs at 72hrs compared to control (n=5, p<0.001). Consistently, FSTL3 and TGF-β mRNA levels, in collected HCMs were significantly increased in DOX-treated cells. Co-treatment of DOX with human anti-FSTL3 antibodies at 10ug/mL significantly improved HCM viability compared to IgG control group. Conversely, anti-FSTL3 antibodies provided synergistic anti-cancer effects with DOX: MCF-7 breast cancer cells were significantly reduced when co-treated with DOX and anti-FSTL3 antibody vs. IgG controls. Conclusion We show, for the first time, that: 1) FSTL3 is secreted directly from HCMs; 2) FSTL3 levels (both circulating and mRNA) is markedly elevated with DOX treatment; 3) neutralisation of FSTL3 in DOX-treated HCMs, restored HCM viability; and 4) exhibit synergistic anti-cancer effects with DOX. Taken together, FSTL3 is a potential target for dual anti-cancer and cardioprotective effects. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Heart Foundation of Australia Future Leader FellowshipsNSW Ministry of Health EMC FellowshipNSW Ministry of Health Translational Research Grant

Abstract Background/Introduction Obesity and metabolic dysregulation are closely associated with the pathophysiology of multiple cardiovascular diseases (CVD). To date, the pathophysiological mechanism(s) of obesity and its link with cardiovascular systems remain largely unknown. Adipose tissue inflammation as a result of excessive fat expansion in obesity, leading to increased systemic production of growth factors and recruitment of inflammatory cells have been postulated to be a major factor. Secreted frizzled-related protein 5 (SFRP5) is an anti-inflammatory adipokine that is linked with obesity and metabolic regulation and has been indicated to affect cardiovascular functions. Currently, the role of circulating SFRP5 levels as a biomarker for cardiovascular diseases are poorly understood, with studies yielding discordant results. Purpose This study aims to evaluate the relationship between circulating SFRP5 and cardiovascular functions in a cohort of patients with established CVD. Methods Patients (n=262, 148 male (56.5%), age (68±11 yrs)) presenting to the cardiology unit for cardiovascular investigations were recruited into the study. Plasma SFRP5 levels were measured via enzyme-linked immunosorbent assay (ELISA). Associations between plasma SFRP5 levels, cardiovascular functions, and patients' co-morbidities were analysed using univariate and multivariate analyses. Results Plasma SFRP5 levels were significantly lower in patients presenting with: heart failure (HF) vs non-HF (median; (10.7 vs 31.0; p<0.001); coronary artery disease (CAD) vs non-CAD; (11.0 vs 33.8; p<0.001); and atrial fibrillation (AF) vs non-AF; (11.2 vs 23.2; p=0.001). On univariate analyses, SFRP5 levels also significantly positively correlated with left ventricular ejection fraction (LVEF) (r=0.52, p<0.001), estimated glomerular filtration rate (eGFR) (r=0.16, p=0.02), total cholesterol levels and triglycerides (r=0.29, p<0.001; r=0.17, p<0.01 respectively). Low SFRP5 levels were correlated with high C-reactive protein (CRP) and E/E' (r=−0.29, p<0.001, r=−0.30, p<0.001, respectively). Patients with HF, CAD, statin use, low LVEF, low triglycerides, high CRP and high eGFR were associated with lower SFRP5 levels independent of age, BMI or diabetes on multivariate analysis (overall model r=0.729, SE=0.638). Conclusion Our results show that low plasma SFRP5 levels are independently associated with HF, CAD, and impaired systolic and diastolic functions. These results suggest that SFRP5 may regulate cardiovascular functions independent of obesity and metabolic regulations. Funding Acknowledgement Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Heart Foundation of Australia Future Leader FellowshipsNSW Ministry of Health EMC FellowshipHeart Foundation of Australia Future Leader Fellowship

Abstract Background/Introduction Age and sexual dimorphism contribute to the differential cardiometabolic dysfunctions associated with diet-induced obesity. However, the underlying mechanisms remain elusive. RNA modifications via RNA m6A methylation, is an emerging mediator of RNA stability, translation and localization responsible for regulation of multiple biological functions. RNA m6A modifications are regulated by “writers”, “erasers” and “readers”. The role of RNA methylation machinery genes in the heart is largely unexplored, and may provide insight into the influence of age and sex on cardiometabolic dysfunction. Purpose We aim to determine differential RNA methylation changes within the heart in a diet-induced cardiomyopathy mouse model, stratified according to age and sex. Methods Male and female C57BL/6 mice (6–8wk-old) were fed normal chow (NC) or high-fat/high-sucrose (HFHS) diet for 1 or 4 months. Echocardiographic measurements were performed at 1 and 4 months according to the American Society of Echocardiography and European Association of Cardiovascular Imaging guidelines. At study endpoint, glucose and insulin tolerance testing was conducted by injecting mice intraperitoneally with 2g/kg glucose or 0.6U/kg insulin, and monitoring blood glucose levels over a 2 hour period. RNA from heart tissue was subjected to quantitative PCR for RNA methylation machinery genes (FTO, ALKBH5, METTL3, METTL4, METTL14, YTHDF1 and YTHDF2). PPIA was used to normalise qPCR data. Results Both male and female mice showed evidence of age- and diet-induced metabolic dysfunction, however, males and females showed markedly different metabolic impairments. For example, glucose tolerance was exacerbated by 4 months of HFHS diet in males but not females; and only females showed impaired insulin tolerance. Echocardiography showed that males had systolic (stoke volume, cardiac output) and diastolic (E/A ratio) dysfunction after 4 months of HFHS diet, while females were unperturbed. We identified that METTL3 and METTL14, the “writers” of m6A methylation, were consistently increased in male mouse hearts at 1 vs 4 months of age but were unchanged or decreased in females, irrespective of diet. Conversely, YTHDF1, a “reader”, was unchanged in male mouse hearts at 1 vs. 4 months of age but was significantly increased in female hearts. Conclusion Our study confirms that markedly different cardiometabolic impairments occur in male versus female mice in response to long-term HFHS diet. Despite significant metabolic impairment in both sexes, cardiac dysfunction was only evident in males. RNA methylation machinery genes were differentially expressed in mouse hearts according to age and sex, suggesting that RNA methylation may be involved in age-related sexual dimorphism in cardiometabolic impairments. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Heart Foundation

Purpose of Review Breast cancer survival rate has greatly improved in the last two decades due to the emergence of next-generation anti-cancer agents. However, cardiotoxicity remains a significant adverse effect arising from traditional and emerging chemotherapies as well as targeted therapies for breast cancer patients. In this review, we will discuss cardiotoxicities of both traditional and emerging therapies for breast cancer. We will discuss current practices to detect cardiotoxicity of these therapies with the focus on new and emerging biomarkers. We will then focus on ‘omics approaches, especially the use of epigenetics to discover novel biomarkers and therapeutics to mitigate cardiotoxicity. Recent Findings Significant cardiotoxicities of conventional chemotherapies remain and new and unpredictable new forms of cardiac and/or vascular toxicity emerge with the surge in novel and targeted therapies. Yet, there is no clear guidance on detection of cardiotoxicity, except for significant left ventricular systolic dysfunction, and even then, there is no uniform definition of what constitutes cardiotoxicity. The gold standard for detection of cardiotoxicity involves a serial echocardiography in conjunction with blood-based biomarkers to detect early subclinical cardiac dysfunction. However, the ability of these tests to detect early disease remains limited and not all forms of toxicity are detectable with these modalities. Summary There is an unprecedented need to discover novel biomarkers that are sensitive and specific for early detection of subclinical cardiotoxicity. In that space, novel echocardiographic techniques, such as strain, are becoming more common-place and new biomarkers, discovered by epigenetic approaches, seem to become promising alternatives or adjuncts to conventional non-specific cardiac biomarkers.

Immunoglobulin G (IgG) is the commonest circulating antibody in humans. Cardiac IgG deposits and elevated circulating IgG levels have been observed in patients with left ventricular systolic and diastolic dysfunction, suggesting it may play a role in cardiac remodelling. Interestingly, commercially available IgG1 proteins are commonly used as an injectable isotype control in multiple animal models including those of heart failure. In this study, we aimed to determine whether these IgG1 isotype controls can have an effect on myocardial function in murine model of diet-induced cardiometabolic dysfunction.

Follistatin-like 3 (FSTL3) is a secreted protein that has been suggested to play an important role in modulating cardiac remodelling and hypertrophy. In this study, we aim to determine whether: 1) FSTL3 is incrementally elevated in patients with HF vs those with other cardiovascular disease (CVD); and 2) increased FSTL3 is associated with 2 or more hospital admissions due to major adverse CV events (MACE) within 1 year.

Abstract Background Obesity is associated with significant cardio-metabolic complications. Adipokines, and cytokines released from adipose tissue (AT) stimulate excessive mitochondrial production of reactive oxygen species (ROS). ROS-mediated oxidative modifications is associated with development of insulin resistance and impaired cardiac function. We hypothesised that adipose-targeted overexpression of mitochondrial-targeted catalase (AT-mCAT) could lead to improvement in diet-induced cardio-metabolic dysfunction. Methods/Results mCAT (floxed) and AdipoQ-Cre mice were crossed to generate mice overexpressing catalase with a mitochondrial-targeting sequence predominantly in AT (AT-mCAT). Wild-type (WT) and AT-mCAT male mice were fed normal chow (NC) or high-fat/high-sucrose (HFHS) diet (36%fat/34%sucrose) for 4 months. At endpoint, echocardiography showed reduced cardiac output in all groups v WT NC (p<0.05); reduced IVSd in AT-mCAT NC and HFHS groups v WT NC (p<0.01); reduced left ventricular ejection fraction in AT-mCAT HFHS v WT NC (p<0.05) and no differences in fractional shortening or E/A ratio between groups. Glucose tolerance tests (2g/kg) showed impairment in WT HFHS and AT-mCAT HFHS v WT NC (p<0.01, p<0.05 respectively). Triglyceride levels were increased in WT HFHS and AT-mCAT HFHS v WT NC (p<0.05). Analysis of hypertrophic signalling in cardiac tissues by ELISA showed p-AKT/total Akt levels were decreased in AT-mCAT hearts regardless of diet (WT NC v AT-mCAT NC p<0.01; WT HFHS v AT-mCAT HFHS p<0.05). Conclusion Our results confirm previous findings that diet-induced obesity is a systemic condition. Targeting adipose tissue with mitochondrial catalase may not be adequate to prevent development of cardio-metabolic dysfunction. More systemic approaches may be required to combat obesity-induced cardio-metabolic impairment. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Heart Foundation of Australia

Pulmonary arterial hypertension (PAH) is characterised by pulmonary vasoconstriction and vascular remodelling, ultimately leading to heart failure and death. Excessive pulmonary fibroproliferation is the suggested mechanism underlying pathogenesis of PAH. Follistatin-like3 (FSTL3) is a pro-fibrotic inhibitor of the TGF-ß superfamily members and is increased in patients with heart failure (HF). FSTL3 is an inhibitor of Growth-Differentiating Factor-11 (GDF-11). GDF-11 was recently shown to be involved in the development of PAH and vascular remodelling in a rat model. In this pilot study, we aim to determine FSTL3 and GDF-11 mRNA transcripts in polymorphonuclear cells (PMC) from patients with PAH vs those with HF.

Abstract Introduction Follistatin-like 3 (FSTL3) is a secreted protein that has been suggested to play an important role in modulating cardiac remodeling and hypertrophy. In this study, we aim to determine whether: 1) FSTL3 is incrementally elevated in patients with HF vs those with other cardiovascular disease (CVD); and 2) increased FSTL3 is associated with 2 or more hospital admissions due to major adverse CV events (MACE) within 1 year. Methods and results We measured circulating levels of FSTL3 using commercially available ELISA (R&D systems) in a total of n=696 patients. FSTL3 levels were compared between: 1) healthy-aging volunteers with no prior major CVD (n=267, age 67±6 years) and 2) patients admitted to cardiology unit for various CVD (n=429, age 66±14 years); among those (n=178, age 68±13 years) had HF. Patients with HF had 2-fold higher FSTL3 levels vs healthy age-matched controls vs those with other CVD (p<0.001). Occurrences of MACE were recorded up to 1 year for patients admitted to cardiology unit. On univariate analyses, patient with 2 or more MACE within 1 year (n=91, 27%) had significant elevated FSTL3 levels (P=0.003), is associated with older age (P<0.005). On multivariate analysis, high FSTL3 levels (P=0.034) is an independent predictor of 2 or more MACE admissions within 1 year after adjusting for age, clinical comorbidities and medications. Conclusions FSTL3 is incrementally increased in patients with HF and is associated with poorer prognosis. Elevated FSTL3 levels is associated with increased risks of cardiac hospital readmissions for patients with multiple CV morbidities. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NSW Ministry of Health EMC Fellowship (Australia)

Modern cancer therapies have led to improved survival rates for many cancers. Rates of cardiovascular diseases (CVD) and risk factors are increased in cancer patients and survivors compared with the general population, and CVD has emerged as a leading cause of long-term morbidity and mortality in

Introduction: Adipose tissue (AT) microvascular function is important in regulating AT health, and overall metabolic function. Overexpansion of AT in obesity is associated with microvascular dysfunction. The anti-angiogenic isoform of VEGF-A: VEGF-A165b has been shown to modulate AT angiogenesis and vascular endothelial function in obesity. In this study, we aim to determine whether targeted inhibition of VEGF-A165b will result in changes in AT and metabolic function. Methods and Results: C57bl/6 mice were fed either normal chow (NC) or high-fat/high-sucrose (HF/HS) diet (36% fat/34% sucrose) for 1 month to induce obesity. Mice were divided into 4 groups of treatment (n = 8 per group): (1) NC + IgG isotype control intraperitoneal injection (IP) (100 ug/100 uL), (2) NC + VEGF-A165b neutralising antibody (IP, 100 ug/100 uL), (3) HF/HS diet + IgG injection, and (4) HF/HS + VEGF-A165b neutralising antibody. Mice fed a NC diet with VEGF-A165b treatment had significant weight gain vs IgG control (p < 0.05). While there was significant weight gain between NC vs HF/HS (p = 0.01) in the IgG control group; there was no difference in weight gain between NC vs. HF/HS feeding in the VEGF-A165b group. Upon glucose tolerance test (2 g/kg), NC + VEGF-A165b treatment had some impairment in glucose tolerance vs IgG control (p = 0.06); HFHS+VEGF-A165b resulted in significant impairment in glucose tolerance vs. NC + EGF-A165b (p < 0.05). Neutralisation of anti-angiogenic VEGF-A165b resulted in significant increase in aortic sprout counts using Matrigel assays (p < 0.05). Conclusions: At 1 month of diet-induced obesity, neutralisation of the anti-angiogenic isoform VEGF-A165b resulted in increase in weight gain and metabolic impairment.