Sirtuins (SIRT) exhibit deacetylation or ADP-ribosyltransferase activity and regulate a wide range of cellular processes in the nucleus, mitochondria and cytoplasm. The role of the only sirtuin that resides in the cytoplasm, SIRT2, in the development of ischemic injury and cardiac hypertrophy is not known. In this paper, we show that the hearts of mice with deletion of Sirt2 (Sirt2-/-) display improved cardiac function after ischemia-reperfusion (I/R) and pressure overload (PO), suggesting that SIRT2 exerts maladaptive effects in the heart in response to stress. Similar results were obtained in mice with cardiomyocyte-specific Sirt2 deletion. Mechanistic studies suggest that SIRT2 modulates cellular levels and activity of nuclear factor (erythroid-derived 2)-like 2 (NRF2), which results in reduced expression of antioxidant proteins. Deletion of Nrf2 in the hearts of Sirt2-/- mice reversed protection after PO. Finally, treatment of mouse hearts with a specific SIRT2 inhibitor reduced cardiac size and attenuates cardiac hypertrophy in response to PO. These data indicate that SIRT2 has detrimental effects in the heart and plays a role in cardiac response to injury and the progression of cardiac hypertrophy, which makes this protein a unique member of the SIRT family. Additionally, our studies provide a novel approach for treatment of cardiac hypertrophy and injury by targeting SIRT2 pharmacologically, providing a novel avenue for the treatment of these disorders.

PMID:37728319 | DOI:10.7554/eLife.85571

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PubMed articles on: Cardio-Oncology

Mitochondrial dysfunction at the crossroad of cardiovascular diseases and cancer

J Transl Med. 2023 Sep 19;21(1):635. doi: 10.1186/s12967-023-04498-5.

ABSTRACT

A large body of evidence indicates the existence of a complex pathophysiological relationship between cardiovascular diseases and cancer. Mitochondria are crucial organelles whose optimal activity is determined by quality control systems, which regulate critical cellular events, ranging from intermediary metabolism and calcium signaling to mitochondrial dynamics, cell death and mitophagy. Emerging data indicate that impaired mitochondrial quality control drives myocardial dysfunction occurring in several heart diseases, including cardiac hypertrophy, myocardial infarction, ischaemia/reperfusion damage and metabolic cardiomyopathies. On the other hand, diverse human cancers also dysregulate mitochondrial quality control to promote their initiation and progression, suggesting that modulating mitochondrial homeostasis may represent a promising therapeutic strategy both in cardiology and oncology. In this review, first we briefly introduce the physiological mechanisms underlying the mitochondrial quality control system, and then summarize the current understanding about the impact of dysregulated mitochondrial functions in cardiovascular diseases and cancer. We also discuss key mitochondrial mechanisms underlying the increased risk of cardiovascular complications secondary to the main current anticancer strategies, highlighting the potential of strategies aimed at alleviating mitochondrial impairment-related cardiac dysfunction and tumorigenesis. It is hoped that this summary can provide novel insights into precision medicine approaches to reduce cardiovascular and cancer morbidities and mortalities.

PMID:37726810 | PMC:PMC10507834 | DOI:10.1186/s12967-023-04498-5

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PubMed articles on: Cardio-Oncology

In-hospital outcomes after acute myocardial infarction with obstructive coronary artery disease in critically ill patients hospitalized for non-cardiac disease

Ann Intensive Care. 2023 Sep 19;13(1):87. doi: 10.1186/s13613-023-01188-9.

ABSTRACT

BACKGROUND: Acute myocardial infarction (AMI) is one of the major cardiac complications in patients hospitalized in the intensive care unit (ICU) for non-cardiac disease. A better knowledge of ischemic and bleeding risks in these patients is needed to identify those most likely to benefit from specific cardiac management. We therefore assessed the incidence and predictors of a composite outcome of severe ischemic event (AMI recurrence, ischemic stroke), major bleeding, or all-cause death in this setting.

METHODS: In this multicenter retrospective study, all consecutive adult patients admitted for non-cardiac disease to four French university hospital ICUs between January 2012 and December 2018 who had an AMI with obstructive coronary artery disease (OCAD) during the ICU stay were considered for inclusion. AMI with OCAD was defined as an elevated cardiac troponin value associated with at least one sign (clinical, electrocardiographic, or echocardiographic) suggestive of myocardial ischemia and presence of OCAD on coronary angiography. The primary endpoint was in-hospital occurrence of the composite outcome.

RESULTS: Ninety-six patients [median age 69 years, 22 women (23%), 59 with sepsis (61%), 35 with ST elevation (37%), median sequential organ failure assessment (SOFA) of 8 on the day of AMI] were included. The median peak cardiac troponin value was 131 (IQR 44-303) times the upper reference limit. Dual antiplatelet, therapeutic anticoagulation, and early mechanical reperfusion therapies were administered in 61 (64%), 68 (71%), and 47 (49%) patients, respectively. The composite outcome occurred in 48 (50%) patients. Severe ischemic events occurred in 17 (18%) patients and major bleeding in 26 (27%) patients; 26 patients (27%) died in the hospital. AMI management was not significantly different in patients with and without the composite outcome. A history of arterial hypertension (HR 2.05, 95% CI 1.01-4.16) and high SOFA score at the time of AMI (HR 1.07, 95% CI 1.00-1.15) were independent risk factors for the composite outcome.

CONCLUSIONS: Patients who have an AMI with OCAD during an ICU stay for non-cardiac disease are at risk of a composite outcome of severe ischemia, major bleeding, and death. A history of arterial hypertension and high SOFA scores were independent hazards for poor prognosis.

PMID:37725298 | PMC:PMC10509106 | DOI:10.1186/s13613-023-01188-9

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Cardiotoxicity News

PubMed articles on: Cancer & VTE/PE

The Role of Mechanical Thrombectomy for Acute Massive Pulmonary Embolism in a Patient With Unilateral Lung Transplant and Atrial Septal Defect

J Endovasc Ther. 2023 Sep 30:15266028231201357. doi: 10.1177/15266028231201357. Online ahead of print.