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Accumulating evidence suggests that modifications of gut function and microbiota composition might play a pivotal role in the pathophysiology of several cardiovascular diseases, including heart failure (HF). In this study we systematically analysed gut microbiota composition, intestinal barrier integrity, intestinal and serum cytokines and serum endotoxin levels in C57BL/6 mice undergoing pressure overload by transverse aortic constriction (TAC) for 1 and 4 weeks. Compared to sham-operated animals, TAC induced prompt and strong weakening of intestinal barrier integrity, long-lasting decrease of colon anti-inflammatory cytokine levels, significant increases of serum levels of bacterial lipopolysaccharide and proinflammatory cytokines. TAC also exerted effects on microbiota composition, inducing significant differences in bacterial genera inside Actinobacteria, Firmicutes, Proteobacteria and TM7 phyla as shown by 16S rDNA sequencing of fecal samples from TAC or sham mice. These results suggest that gut modifications represent an important element to be considered in the development and progression of cardiac dysfunction in response to TAC and support this animal model as a valuable tool to establish the role and mechanisms of gut-heart crosstalk in HF. Evidence arising in this field might identify new treatment options targeting gut integrity and microbiota components to face adverse cardiac events.

A strict bidirectional relationship exists between diabetes mellitus and heart failure. Diabetic cardiomyopathy is a specific cardiac manifestation of patients with diabetes characterized by left ventricular hypertrophy and diastolic dysfunction in the early phase up to overt heart failure with reduced systolic function in the advanced stages. The pathogenesis of this condition is multifactorial and recognizes as main promoting factors the presence of insulin resistance and hyperglycemia. Diabetic cardiomyopathy exerts a negative prognostic impact in affected patients and no target treatments are currently available. More efforts are needed to better define the diagnostic and therapeutic approach in this specific setting.

Some components of Nutraceuticals (NUT) such as red yeast rice and Morus alba have demonstrated positive effects on the endothelial function in hypercholesterolemic subjects. Our aim was to compare the effects of two different NUT combinations on cold pressure test (CPT) derived coronary flow reserve (CFR) assessed by transthoracic echo-Doppler. In a randomized, single-blind study, 28 consecutive patients with a variety of cardiovascular risk factors received NUT A (LopiGLIK®: berberine, red yeast rice powder, and leaf extract of Morus alba) or B (Armolipid Plus®: policosanol, red yeast rice, berberine, astaxantine, folic acidandcoenzyme Q10). An echo-Doppler exam with evaluation of CFR was performed at baseline, 2 h (acute test) and 30 days after daily NUT assumption. Blood sampling for metabolic profile and platelet aggregometry was performed at baseline and after 30 days of daily NUT assumption. CFR was not significantly modified at the acute test. After 30 days, CFR improved with NUT A (p

Platelet aggregation plays a pivotal role in acute coronary syndrome (ACS). In this setting, β-blockers (BBs) are used to counteract the effects of catecholamines on heart. Circulating catecholamines can also potentiate platelet reactivity, mainly through α2- and β2-adrenoceptors on human platelets' surface, thus BB may affect platelet aggregation; however, the effects of different BBs on platelet aggregation in contemporary-treated patients with ACS have been poorly investigated. One hundred patients with ACS on dual antiplatelet therapy with aspirin and ticagrelor were randomized to receive treatment with carvedilol, a nonselective BB (n = 50), or metoprolol, a selective β1-blocker (n = 50), at maximum tolerated dose. Light transmission aggregometry was performed at randomization (T0) and at 30-day follow-up (T30), and the results were expressed as a percentage of maximum platelet aggregation (MPA). The primary end point was epinephrine-induced MPA at 30 days. Patients were predominantly men (80%), and mean age was 57.3 ± 9.7 years. The 2 randomized groups were well balanced for baseline characteristics. At T0, mean MPA was similar between the groups (18.96 ± 9.05 vs 18.32 ± 9.21 with 10 µM epinephrine, 14.42 ± 9.43 vs 15.98 ± 10.08 with 20 µM adenosine diphophate (ADP), and 13.26 ± 9.83 vs 14.30 ± 9.40 with 10 µM ADP for carvedilol and metoprolol, respectively, all p = NS). At 30 days, platelet aggregation induced by epinephrine was significantly lower in the carvedilol group than in the metoprolol group (23.52 ± 10.25 vs 28.72 ± 14.37, p = 0.04), with a trend toward the lower values of ADP-induced MPA (20 µM ADP 19.42 ± 13.84 vs 24.16 ± 13.62, p = 0.09; 10 µM ADP 19.12 ± 12.40 vs 22.57 ± 13.59, p = 0.19). In conclusion, carvedilol, a nonselective BB, reduces residual platelet reactivity in patients with ACS compared with the selective BB, metoprolol.

MitoAKAPs (mitochondrial A kinase anchoring proteins), encoded by the Akap1 gene, regulate multiple cellular processes governing mitochondrial homeostasis and cell viability. Although mitochondrial alterations have been associated to endothelial dysfunction, the role of mitoAKAPs in the vasculature is currently unknown. To test this, postischemic neovascularization, vascular function, and arterial blood pressure were analyzed in Akap1 knockout mice ( Akap1 −/− ) and their wild-type (wt) littermates. Primary cultures of aortic endothelial cells (ECs) were also obtained from Akap1 −/− and wt mice, and ECs migration, proliferation, survival, and capillary-like network formation were analyzed under different experimental conditions. After femoral artery ligation, Akap1 −/− mice displayed impaired blood flow and functional recovery, reduced skeletal muscle capillary density, and Akt phosphorylation compared with wt mice. In Akap1 −/− ECs, a significant enhancement of hypoxia-induced mitophagy, mitochondrial dysfunction, reactive oxygen species production, and apoptosis were observed. Consistently, capillary-like network formation, migration, proliferation, and AKT phosphorylation were reduced in Akap1 −/− ECs. Alterations in Akap1 −/− ECs behavior were also confirmed in Akap1 −/− mice, which exhibited a selective reduction in acetylcholine-induced vasorelaxation in mesenteric arteries and a mild but significant increase in arterial blood pressure levels compared with wt. Finally, overexpression of a constitutively active Akt mutant restored vascular reactivity and ECs function in Akap1 −/− conditions. These results demonstrate the important role of mitoAKAPs in the modulation of multiple ECs functions in vivo and in vitro, suggesting that mitochondria-dependent regulation of ECs might represent a novel therapeutic approach in cardiovascular diseases characterized by endothelial dysfunction.

Left ventricular hypertrophy (LVH) is a major contributor to the development of heart failure (HF). Alterations in cyclic adenosine monophosphate (cAMP)-dependent signaling pathways participate in cardiomyocyte hypertrophy and mitochondrial dysfunction occurring in LVH and HF. cAMP signals are received and integrated by a family of cAMP-dependent protein kinase A (PKA) anchor proteins (AKAPs), tethering PKA to discrete cellular locations. AKAPs encoded by the Akap1 gene (mitoAKAPs) promote PKA mitochondrial targeting, regulating mitochondrial structure and function, reactive oxygen species production, and cell survival. To determine the role of mitoAKAPs in LVH development, in the present investigation, mice with global genetic deletion of Akap1 (Akap1(-/-)), Akap1 heterozygous (Akap1(+/-)), and their wild-type (wt) littermates underwent transverse aortic constriction (TAC) or SHAM procedure for 1 week. In wt mice, pressure overload induced the downregulation of AKAP121, the major cardiac mitoAKAP. Compared to wt, Akap1(-/-) mice did not display basal alterations in cardiac structure or function and cardiomyocyte size or fibrosis. However, loss of Akap1 exacerbated LVH and cardiomyocyte hypertrophy induced by pressure overload and accelerated the progression toward HF in TAC mice, and these changes were not observed upon prevention of AKAP121 degradation in seven in absentia homolog 2 (Siah2) knockout mice (Siah2(-/-)). Loss of Akap1 was also associated to a significant increase in cardiac apoptosis as well as lack of activation of Akt signaling after pressure overload. Taken together, these results demonstrate that in vivo genetic deletion of Akap1 enhances LVH development and accelerates pressure overload-induced cardiac dysfunction, pointing at Akap1 as a novel repressor of pathological LVH. These results confirm and extend the important role of mitoAKAPs in cardiac response to stress.

Despite important advances in diagnosis and treatment, heart failure (HF) remains a syndrome with substantial morbidity and dismal prognosis. Although implementation and optimization of existing technologies and drugs may lead to better management of HF, new or alternative strategies are desirable. In this regard, basic science is expected to give fundamental inputs, by expanding the knowledge of the pathways underlying HF development and progression, identifying approaches that may improve HF detection and prognostic stratification, and finding novel treatments. Here, we discuss recent basic science insights that encompass major areas of translational research in HF and have high potential clinical impact.

A-kinase anchoring proteins (AKAPs) transmit signals cues from seven-transmembrane receptors to specific sub-cellular locations. Mitochondrial AKAPs encoded by the Akap1 gene have been shown to modulate mitochondrial function and reactive oxygen species (ROS) production in the heart. Under conditions of hypoxia, mitochondrial AKAP121 undergoes proteolytic degradation mediated, at least in part, by the E3 ubiquitin ligase Seven In-Absentia Homolog 2 (Siah2). In the present study we hypothesized that Akap1 might be crucial to preserve mitochondrial function and structure, and cardiac responses to myocardial ischemia. To test this, eight-week-old Akap1 knockout mice (Akap1(-/-)), Siah2 knockout mice (Siah2(-/-)) or their wild-type (wt) littermates underwent myocardial infarction (MI) by permanent left coronary artery ligation. Age and gender matched mice of either genotype underwent a left thoracotomy without coronary ligation and were used as controls (sham). Twenty-four hours after coronary ligation, Akap1(-/-) mice displayed larger infarct size compared to Siah2(-/-) or wt mice. One week after MI, cardiac function and survival were also significantly reduced in Akap1(-/-) mice, while cardiac fibrosis was significantly increased. Akap1 deletion was associated with remarkable mitochondrial structural abnormalities at electron microscopy, increased ROS production and reduced mitochondrial function after MI. These alterations were associated with enhanced cardiac mitophagy and apoptosis. Autophagy inhibition by 3-methyladenine significantly reduced apoptosis and ameliorated cardiac dysfunction following MI in Akap1(-/-) mice. These results demonstrate that Akap1 deficiency promotes cardiac mitochondrial aberrations and mitophagy, enhancing infarct size, pathological cardiac remodeling and mortality under ischemic conditions. Thus, mitochondrial AKAPs might represent important players in the development of post-ischemic cardiac remodeling and novel therapeutic targets.