Search

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.

Background Mitochondrial A-kinase anchoring proteins (mitoAKAPs) encoded by the Akap1 gene are crucially involved in multiple cellular processes, including cardiomyocyte survival and function. There is a correlation between ROS production, intestinal permeability and the composition of the intestinal microbiota, especially during aging. Whether Akap1 deletion affects microbiota composition, intestinal function during senescence is currently unknown. Purpose The purpose of the study was to shed light into the complex interplay between gut permeability and microbiota composition, cardiac function and aging in adult (6-month-old, 6m) and old (24-month-old, 24m) Akap 1 wild type (Akap1+/+) or Akap1 heterozygous knockout mice (Akap1+/−). Methods Cardiac function was non-invasively analyzed by echocardiography in adult and old, Akap1+/+ and Akap1+/− mice. Colon, serum and feces samples were collected after sacrifice in 6m and 24m mice of either genotype. Intestinal barrier permeability was evaluated in colon samples by Occludin (Ocln) and Tight junction protein ZO-1 (Tjp1) mRNA expression analysis. Systemic inflammation was measured by Tumor Necrosis Factor-alpha (TNF-alpha), Lipopolysaccharide (LPS), Interleukin-10 (IL-10) and Interleukin-1 (IL-1) circulating levels. Microbial DNA was extracted from feces samples and gut microbiota composition was evaluated by Illumina Mi-Seq analysis. Bioinformatic analyses were carried out to identify intestinal populations. Results Akap1 partial deletion accelerated the progression of cardiac dysfunction in 24m mice as demonstrated by a significant reduction of fractional shortening in Akap1+/− 24m mice compared to Akap1+/+ 24m (Figure 1A). Colon permeability was impaired in Akap1+/− 24m as shown by reduced Ocln expression (Figure 1B), while circulating TNF-alpha was increased in Akap1+/− 24m (Figure 1C). Next, we analyzed the differences in abundance of all 2042 Operational Taxonomic Units (OTUs) between age-matched Akap1+/+ and Akap1+/−. We identified 10 OTUs differently represented in Akap1+/+ and Akap1+/− 6m mice, while a bigger set of bacterial OTUs (19) were different between Akap1+/+ and Akap1+/− 24m mice. LDA scores of differentially microbiome abundant taxa in Akap1+/+ and Akap1+/− 24m (Figure 1D) showed different assortment in Clostridiales family (Ruminococcus torques specie), Porphyromonadaceae family (Barseniella intestinihominis specie) and Lachnospiraceae genus (Blautia producta specie), bacterial species that have been previously identified in patients with heart failure and involved in anti-inflammatory mechanisms. Conclusions mitoAKAPs play a crucial role in the maintenance of cardiac function and intestinal barrier during aging, since Akap1 partial deletion promotes gut permeability, bacteria translocation and systemic inflammation associated with systolic cardiac dysfunction. Figure 1 Funding Acknowledgement Type of funding source: Other. Main funding source(s): CP was supported by Ministero dell'Istruzione, Università e Ricerca Scientifica grant (2015583WMX) and Programma STAR grant by Federico II University and Compagnia di San Paolo. RP was supported by a research grant provided by the Cardiopath PhD program. LC was supported by 2018-2019 Postdoctoral Fellowship Grants provided by Fondazione Umberto Veronesi.

AIMS: Chronic kidney disease (CKD) is associated with increased thrombotic events and seems to influence platelet reactivity. Conflicting results have been published on platelet response in CKD patients with stable coronary artery disease. The aim of our study was to investigate the impact of CKD on platelet aggregation in acute coronary syndrome (ACS) patients receiving dual antiplatelet therapy, included the more potent P2Y12 inhibitors. METHODS: We enrolled 206 patients with ACS, divided in two groups, according to the presence or the absence of moderate/severe CKD. Platelet aggregation was performed with light transmission aggregometry and results are expressed as percentage of maximum platelet aggregation. High residual platelet reactivity (HRPR) was defined as maximum platelet aggregation more than 59%. RESULTS: Patients with CKD [estimate glomerular filtration rate (eGFR)

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.

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.