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Background Ataxia Telangiectasia Mutated (ATM) protein kinase is the major sensor of DNA damage response (DDR) and oxidative stress, variously implicated in cellular metabolism. Previous studies on ATM functions in the heart have produced conflicting results. Here we hypothesized that ATM might regulate cardiomyocyte metabolic homeostasis and function. Methods Atm-mutated mice (Atm-/-) and their wild-type littermates (Atm+/+) were used to assess the effects of ATM inactivation on cardiomyocyte hypertrophy, cardiac structure, function, DDR and metabolism under sham conditions or after pressure overload by transverse aortic constriction (TAC). Results ATM inactivation induced cardiomyocyte hypertrophy (FIG.1 A), fetal gene expression re-activation and a specific metabolomic signature in the heart, characterized by significant accumulation of pyruvate, branched chain amino-acids, short-medium acyl-carnitines and metabolites of tricarboxylic acid cycle (FIG.1 C, D),. Importantly, pyruvate was trapped in the cytosol because mitochondrial carriers were suppressed and the enzymes that process pyruvate were dysregulated. As a consequence of pyruvate metabolic block, fatty acids oxidation was inefficient and resulted in the accumulation of acyl-carnitines and insulin resistance. Although these metabolic changes were present constitutively in Atm-/- mice, they were amplified by TAC, which rapidly induced heart failure (FIG.1 B) in Atm-/- mice. ATM inactivation also increased basal and TAC-induced genomic stress in cardiomyocytes, as shown by the levels of p-γ-H2AX, 8-oxodG glycosylase (OGG1/2) and apurinic site nuclease (APE1). Cardiac metabolic changes induced by ATM loss (rise of pyruvate, lactate and succinate levels) were also present in Atm-/- brains, although the basal conditions were different. Conclusions ATM rewires the metabolism of cardiac cells by inducing glycolysis and fatty acids oxidation. Combining metabolomic, DNA damage and cardiac phenotypes, we deduce that ATM stimulates glycolysis to repair DNA lesions and protect the heart against stress-induced dysfunction.

Background Despite optimal therapy, heart failure (HF) remains a relentless and deadly disease. Given the relative inaccessibility of myocardial human tissues, identification of circulating biomarkers mirroring myocardial pathological signaling pathways, especially in peripheral blood mononuclear cells (PBMC) is expected to be extremely relevant. Small Nucleolar RNAs (snoRNAs) have been shown to play important roles in various cellular physiological processes. However, the connection between snoRNAs and pathological dysfunction in the heart or peripheral blood mononuclear cells (PBMC) is still poorly understood. Purpose To identify novel circulating PBMC biomarkers linked to myocardial dysfunction and HF. Methods : Myocardial left ventricle (LV) samples and PBMC were obtained from patients affected by ischemic HF (HF, n =13) undergoing heart transplantation and control donors (CD, n=7) and analyzed by RNA sequencing analysis (RNASeq). SNORD3A expression levels in the different groups were evaluated by quantitative real-time PCR. HF was induced in 8-week-old wild type C57BL/6 mice by transverse aortic constriction (TAC). Sham-operated mice (sham) were used as controls. After twelve-week-TAC (12w) or sham operation, mice were anesthetized, cardiac function was analyzed by echocardiography, and cardiac/PBMC samples were collected after sacrifice. In order to test the role of SNORD3A in cardiomyocyte hypoxia, H9C2 cardiomyoblasts were transfected with SNORD3A-targeted antisense oligonucleotides (ASO) and cell survival was analyzed. Results RnaSeq analysis identified a small set of genes differentially expressed in the heart and PBMC from HF patients. Among these, SNORD3A was up-regulated in cardiac and PBMC samples from HF patients compared to CD (Figure 1A). Similarly, in murine HF induced by 12w TAC, SNORD3A levels were increased by rtPCR, both in the heart and PBMC (Figure 1B). SNORD3A expression levels were also significantly increased in H9C2 cells exposed to in vitro hypoxia (Figure 1C). Interestingly, H9C2 transfection with SNORD3A-specific ASO significantly reduced hypoxia-induced SNORD3A upregulation and reduced hypoxia-induced cell death (Figure 1D). Conclusions In this study, we identify SNORD3A as a novel possible biomarker in human HF, similarly up-regulated in the heart and PBMC, induced by hypoxia in vitro and modulating cell survival.

Background Mitochondrial A-kinase anchoring proteins (mitoAKAP) encoded by the Akap1 gene promote Protein Kinase A mitochondrial targeting, regulating mitochondrial structure and function, reactive oxygen species production and cardiomyocyte survival. Whether mitoAKAP levels play a role in cardiac aging, gut barrier integrity and gut microbiota composition is currently unknown. Purpose The aim of this study was to highlight the complex interplay between cardiac dysfunction, gut barrier integrity, gut microbiota composition and aging in young (6-month-old, 6m) and old (24-month-old, 24m) wild type (wt) and Akap1 heterozygous mice (Akap1+/-). Methods Cardiac function was noninvasively analyzed by echocardiography in 6m and 24m wt and Akap1+/- mice. Gut microbial DNA was extracted and gut microbiota composition was analyzed by Illumina Mi-Seq analysis. Bioinformatics analysis was carried out to identify major intestinal populations. Alpha diversity within each sample was determined, and then analyzed according to genotype and age; then, inter-sample diversity was determined. For each dataset, we used UniFrac to calculate the differences between microbial communities based on phylogenetic distance between taxa sets in a phylogenetic tree. Bioinformatics analyses were performed using the analysis of similarities (ANOSIM). To evaluate the role of mitoAKAPs in intestinal permeability, we analyzed intestinal junction proteins expression levels in colon samples of all groups. Variance analysis was performed to determine significance among the groups. Results Partial loss of Akap1 accelerated the progression of cardiac dysfunction in 24m mice, as demonstrated by a significantly lower % fractional shortening (%FS) compared to 24m wt mice (%FS, wt 6m: 60±3; Akap1-/+ 6m: 58±5; wt 24m: 49±6*; Akap1-/+ 24m: 39±12*§; *p Conclusion Partial Akap1 deletion plays an important role in the progression toward HF and modulates colon permeability and gut microbiota composition during aging. This work highlights the complex interplay between gut microbiota and development of cardiac dysfunction, and characterization of these processes might lead to the development of new diagnostic and therapeutic approaches for cardiac dysfunction.

Aims Complex percutaneous coronary intervention (PCI) patients have greater risk of peri-procedural complications, with potential to be associated with poor short-term and late prognosis. Cangrelor is an intravenous P2Y12 receptor inhibitor characterized by rapid onset and offset effect of platelet inhibition which reduced the risk of thrombotic complications. Cangrelor use is currently approved in patients naïve from oral P2Y12 inhibitors with chronic (CCS) or acute coronary syndrome (ACS) undergoing PCI with a IIb recommendation by European guidelines. Yet, the process of switching from cangrelor to oral P2Y12 inhibitor remains uncertain. Methods and Results POMPEII study (NCT04790032) is a prospective registry conducted at Federico II University of Naples enrolling all patients undergoing PCI and receiving cangrelor administration. Pharmacodynamic (PD) assessments were performed at baseline, at 30 minutes, 3 hours and 4-6 hours after cangrelor initiation with 3 assays: 1) the gold standard light transmittance aggregometry (LTA) (20- and 5-µM adenosine diphosphate [ADP] stimuli); 2) VerifyNow P2Y12-test; 3) Multiplate electrode aggregometry (MEA), ADP-test. We enrolled 41 patients undergoing elective complex PCI. All patients were P2Y12 inhibitor naïve and received aspirin, unfractionated heparin, and cangrelor (30-µg/kg bolus followed by 4-µg/kg/min infusion for 2 hours) prior to the start of PCI per standard of care. All patients showed low P2Y12 reactivity at 30 minutes during cangrelor infusion with a mean inhibition of platelet aggregation (IPA, %) of 55.7±18.0% at LTA 20-µM ADP test (34% with IPA ≤50%, 19.5% with IPA≥70%, 4.9% with IPA ≥80% and none IPA ≥90%). High residual platelet reactivity (HRPR) was observed in 1 case (2.4%) as shown by LTA (both 20- and 5-µM ADP stimuli) but not confirmed by VerifyNow and MEA. HRPR was observed in 55% at at 3h and 22.5% at 4-6h at LTA 20-µM and consistently with other assays. All patients with HRPR after cangrelor stop had received clopidogrel as switching drug, while no HRPR was observed in the 4 patients switching to ticagrelor. Conclusions Cangrelor showed to be effective and safe in patients undergoing complex PCI at high thrombotic risk. The switch from cangrelor to clopidogrel could expose patients to a variable period of on-treatment HRPR with inadequate platelet inhibition probably due to the fast offset of cangrelor effect and delay of oral drug effect, while the use of ticagrelor soon after cangrelor start might be ideal to cover the gap. This might be of relevance in such a delicate clinical setting.

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.

Background: Elderly status is steadily increasing among patients with acute coronary syndrome (ACS). Dual antiplatelet therapy (DAPT) with aspirin and a potent P2Y12 receptor inhibitor is the cornerstone of treatment to prevent recurrent thrombotic complications in patients with ACS. However, DAPT in older patients is challenged by a concurrent heightened risk of ischemia and bleeding. The aim of this study is to evaluate the pharmacodynamic and pharmacokinetic profile of a lower dose of ticagrelor (60 mg twice daily) among elderly patients during the early phase of ACS. Study Design: PLINY THE ELDER (PLatelet INhibition with two different doses of potent P2y12 inhibitors in THE ELDERly population) (NCT04739384) is a prospective, randomized, open-label, crossover trial to evaluate the non-inferiority of a lower dose of ticagrelor (60 mg twice daily) compared with a standard dose (90 mg twice daily) among elderly patients with ACS undergoing percutaneous coronary intervention (PCI). A total of 50 patients, aged 75 years or more, with indication to potent P2Y12 receptor inhibitors will be randomized within 3 days from PCI for the index ACS. Patients with indication to oral anticoagulant therapy, treatment with glycoprotein IIb/IIIa inhibitors, or active bleeding will be excluded. The primary endpoint is platelet reactivity determined by P2Y12 reaction units (PRU) (VerifyNow, Accumetrics, San Diego, CA, USA) after treatment with ticagrelor 60 or 90 mg twice daily for 14 days. Secondary endpoints will include other pharmacodynamic tests of ADP-induced aggregation (light transmittance aggregometry and multiple electrode aggregometry) and determination of pharmacokinetic profile (plasma levels of ticagrelor and its metabolite AR-C124910XX) by high performance liquid chromatography-tandem mass spectrometry. Conclusions: The PLINY THE ELDER trial will determine whether a lower dose of ticagrelor confers non-inferior platelet inhibition compared with the standard dose in the early phase of ACS among elderly patients undergoing PCI, informing future clinical investigation.

Aims Mitochondrial A-kinase anchoring proteins (mitoAKAP) encoded by the Akap1 gene promote Protein Kinase A mitochondrial targeting, regulating mitochondrial structure and function, reactive oxygen species production, and cardiomyocyte survival. Whether mitoAKAP levels play a role in cardiac ageing, gut barrier integrity and gut microbiota composition is currently unknown. The aim of this study was to highlight the complex interplay between cardiac dysfunction, gut barrier integrity, gut microbiota composition and ageing in young (6-month-old, 6 m) and old (24-month-old, 24 m) wild type (wt) and Akap1 heterozygous mice (Akap1+/−). Methods and results Cardiac function was noninvasively analysed by echocardiography in 6 m and 24 m wt and Akap1+/− mice. Gut microbial DNA was extracted and gut microbiota composition was analysed by Illumina Mi-Seq analysis. Bioinformatics analysis was carried out to identify major intestinal populations. Alpha diversity within each sample was determined, and then analysed according to genotype and age; then, inter-sample diversity was determined. For each dataset, we used UniFrac to calculate the differences between microbial communities based on phylogenetic distance between taxa sets in a phylogenetic tree. Bioinformatics analyses were performed using the analysis of similarities (ANOSIM). To evaluate the role of mitoAKAPs in intestinal permeability, we analysed intestinal junction proteins expression levels in colon samples of all groups. Variance analysis was performed to determine significance among the groups. Partial loss of Akap1 accelerated the progression of cardiac dysfunction in 24 m mice, as demonstrated by a significantly lower % fractional shortening (%FS) compared to 24 m wt mice (%FS, wt 6 m: 60 ± 3; Akap1−/+ 6 m: 58 ± 5; wt 24 m: 49 ± 6*; Akap1−/+ 24 m: 39 ± 12*§; *P Conclusions Partial Akap1 deletion plays an important role in the progression towards HF and modulates colon permeability and gut microbiota composition during ageing. This work highlights the complex interplay between gut microbiota and development of cardiac dysfunction, and characterization of these processes might lead to the development of new diagnostic and therapeutic approaches for cardiac dysfunction.

Aims Despite optimal therapy, heart failure (HF) remains a relentless and deadly disease. Given the relative inaccessibility of myocardial human tissues, identification of circulating biomarkers mirroring myocardial pathological signalling pathways, especially in peripheral blood mononuclear cells (PBMC) is expected to be extremely relevant. Small Nucleolar RNAs (snoRNAs) have been shown to play important roles in various cellular physiological processes. However, the connection between snoRNAs and pathological dysfunction in the heart or peripheral blood mononuclear cells (PBMC) is still poorly understood. To identify novel circulating PBMC biomarkers linked to myocardial dysfunction and HF. Methods Myocardial left ventricle (LV) samples and PBMC were obtained from patients affected by ischaemic HF (HF, n = 13) undergoing heart transplantation and control donors (CD, n = 7) and analysed by RNA sequencing analysis (RNASeq). SNORD3A expression levels in the different groups were evaluated by quantitative real-time PCR. HF was induced in 8-week-old wild type C57BL/6 mice by transverse aortic constriction (TAC). Sham-operated mice (sham) were used as controls. After 12-week-TAC (12w) or sham operation, mice were anesthetized, cardiac function was analysed by echocardiography, and cardiac/PBMC samples were collected after sacrifice. In order to test the role of SNORD3A in cardiomyocyte hypoxia, H9C2 cardiomyoblasts were transfected with SNORD3A-targeted antisense oligonucleotides (ASO) and cell survival was analysed. Results RNASeq analysis identified a small set of genes differentially expressed in the heart and PBMC from HF patients. Among these, SNORD3A was up-regulated in cardiac and PBMC samples from HF patients compared to CD (Figure 1A). Similarly, in murine HF induced by 12w TAC, SNORD3A levels were increased by rtPCR, both in the heart and PBMC (Figure 1B). SNORD3A expression levels were also significantly increased in H9C2 cells exposed to in vitro hypoxia (Figure 1C). Interestingly, H9C2 transfection with SNORD3A-specific ASO significantly reduced hypoxia-induced SNORD3A up-regulation and reduced hypoxia-induced cell death (Figure 1D). Conclusions In this study, we identify SNORD3A as a novel possible biomarker in human HF, similarly up-regulated in the heart and PBMC, induced by hypoxia in vitro and modulating cell survival.

Background Despite optimal therapy, heart failure (HF) remains a relentless and deadly disease. Given the relative inaccessibility of myocardial human tissues, identification of circulating biomarkers mirroring myocardial pathological signaling pathways, especially in peripheral blood mononuclear cells (PBMC) is expected to be extremely relevant. Small Nucleolar RNAs (snoRNAs) have been shown to play important roles in various cellular physiological processes. However, the connection between snoRNAs and pathological dysfunction in the heart or peripheral blood mononuclear cells (PBMC) is still poorly understood. Purpose To identify novel circulating PBMC biomarkers linked to myocardial dysfunction and HF. Methods Myocardial left ventricle (LV) samples and PBMC were obtained from patients affected by ischemic HF (HF, n=13) undergoing heart transplantation and control donors (CD, n=7) and analyzed by RNA sequencing analysis (RNASeq). SNORD3A expression levels in the different groups were evaluated by quantitative real-time PCR. HF was induced in 8-week-old wild type C57BL/6 mice by transverse aortic constriction (TAC). Sham-operated mice (sham) were used as controls. After twelve-week-TAC (12w) or sham operation, mice were anesthetized, cardiac function was analyzed by echocardiography, and cardiac/PBMC samples were collected after sacrifice. In order to test the role of SNORD3A in cardiomyocyte hypoxia, H9C2 cardiomyoblasts were transfected with SNORD3A-targeted antisense oligonucleotides (ASO) and cell survival was analyzed by cleaved caspase-3 and PARP1 immunoblotting. Results RnaSeq analysis identified a small set of genes differentially expressed in the heart and PBMC from HF patients. Among these, SNORD3A was up-regulated in cardiac and PBMC samples from HF patients compared to CD (Figure 1A-B). Similarly, in murine HF induced by 12w TAC, SNORD3A levels were increased by rtPCR, both in the heart and PBMC (Figure 1C-D). SNORD3A expression levels were also significantly increased in H9C2 cells exposed to in vitro hypoxia (Figure 1E). Interestingly, H9C2 transfection with SNORD3A-specific ASO significantly reduced hypoxia-induced SNORD3A upregulation and reduced hypoxia-induced cell death (Figure 1F-G). Conclusions In this study, we identify SNORD3A as a novel possible biomarker in human HF, similarly up-regulated in the heart and PBMC, induced by hypoxia in vitro and modulating cell survival. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): STAR GRANT Figure 1

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.

Introduction Pressure overload-induced cardiac hypertrophy is associated with increased reactive oxygen species (ROS), inducing DNA damage and activating the protein kinase Ataxia-Telangiectasia Mutated (ATM). Recently, ATM has been also involved in the regulation of several metabolic processes, but whether and how it affects cardiac metabolism is still poorly understood. Purpose We hypothesized that ATM might play crucial roles in the maintenance of cardiomyocyte metabolic homeostasis and in the development of cardiac dysfunction in response to pressure overload. Methods Atm+/+ and Atm homozygous mutated mice (Atm−/−) underwent transverse aortic constriction (TAC) or sham operation (sham). After one week (1w), sham and TAC mice were anesthetized, cardiac function and morphometry were analyzed, and gene expression reprogramming, cardiac histology, mitochondrial morphology were performed. Metabolic profiling was carried out through untargeted metabolomics (LC-MS/MS and GC/MS), mRNA and/or protein levels analysis to investigate glycolyis, pyruvate oxidation, Krebs cycle, aminoacid synthesis, gluconeogenesis and lipid oxidation. Results Atm genetic inactivation induced cardiomyocytes hypertrophy and fetal gene reprogramming in sham mice, with normal cardiac function and in the absence of fibrosis or mitochondrial dysfunction (Figure 1A). After TAC 1w, cardiac function was significantly decreased in Atm−/− mice, compared to Atm+/+ (Figure 1B). In both sham and TAC 1w Atm−/− mice, significant metabolic abnormalities were identified, including switching of glycolysis, reduction of pyruvate oxidation (Figure 1B), activation of aminoacid synthesis and accumulation of long and short-chain fatty acid conjugated with carnitine. Pyruvate accumulation was associated to a significant reduction of pyruvate carrier (MPC1-MPC2) and pyruvate dehydrogenase (PDH) levels in sham and TAC 1w Atm−/− mice. Conclusions ATM regulates gene expression, cardiomyocyte hypertrophy and cardiac responses to pressure overload, modulating cardiac metabolism and the profile of intracellular substrate utilization in the heart. Thus, ATM might represent a novel important player in the development of cardiac dysfunction and a novel therapeutic target. 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.

Background Microbiota composition plays an important role in the pathophysiology of heart failure (HF). Reduced cardiac output can disrupt intestinal barrier function and promote systemic inflammation through bacterial translocation. Several gut and cardiac pathological conditions are reciprocally linked at multiple levels and through different, still largely undefined mechanisms. Purpose We analyzed the effects of Transverse aortic constriction (TAC) on aortic pressures, gut barrier integrity, systemic inflammation and gut microbiota composition. Methods TAC was induced in C57BL6 mice of either sex. Sham-operated (Sham) mice were used as controls. After one-week (1w) and four weeks (4w), mice have been anesthetized, cardiac function and abdominal aortic blood flow were analyzed. Colon, serum and feces samples were collected after sacrifice. Intestinal barrier integrity was evaluated in colon samples by Tight junction protein ZO-1 (Tjp1) and Occludin (Ocln) mRNA analysis. Circulating levels of Tumor Necrosis Factor-alpha (TNF-alpha), Lipopolysaccharide (LPS), Interleukin-10 and Interleukin-1 were measured. Microbial DNA was extracted from feces samples and gut microbiota composition was evaluated by Illumina Mi-Seq analysis. Results TAC induced left ventricular hypertrophy and systolic dysfunction. Abdominal aortic blood flow was significantly reduced in TAC mice compared to sham (Figure 1A). Decreased intestinal perfusion in TAC mice was associated to a prompt and strong weakening of intestinal barrier integrity and long-lasting decrease of colonic anti-inflammatory cytokine levels, as shown by reduced mRNA expression of interleukin-10 (IL-10) and Occludin (Ocln) (Figure 1B). Serum levels of lipopolysaccharide (LPS) were increased after TAC surgery and significant increases of circulating proinflammatory cytokines tumor necrosis factor-a (TNF-a) were detected in TAC mice (Figure 1C). High-resolution approach was used to obtain bacterial species assignment of key genera with significant differences among groups. After TAC, significant increases of Bifidobacterium, Lactobacillus and Turicibacter, whereas the genus Oscillospira was significantly less (Figure 1D). Butyrate-producing bacteria are considered relevant colonizers of the gastrointestinal tract being butyrate important in anti-inflammation and maintaining intestinal barrier integrity. Oscillospira genus members have been described as butyrate producers. Notably, in old patients with heart failure and in animal models of hypertension, increase in lactate-producing Lactobacillus was found. Conclusions These data indicate a remodeling of specific bacterial species abundance within identified key genera starting soon after TAC, designating a clear effect of the treatment on microbiota profiles and, possibly, on microbiota functionality. Gut dysbiosis may represent an element to be considered in the development or progression of 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.

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)

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.

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.

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.

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.