Explore the vast range of titles available.

The capacity of stem and progenitor cells to stimulate cardiac regeneration has been studied for almost 20 years, with very promising preclinical data and mixed clinical results. Several cell types have been studied, identified by their cell surface markers, differentiation capacity and their secreted growth factors. Bone marrow derived mesenchymal stem cells (MSCs) have been found to have potent regenerative capacity, through multiple mechanisms, including mesoderm lineage differentiation, immunomodulation, and paracrine stimulation. MSCs also secrete exosomes and microvesicles, which themselves contain potent angiogenic cytokines or mRNA molecules with effects on their local milieu. This concise review summarizes the mechanisms of MSC‐based cardiac regeneration and highlighting results from molecular and preclinical studies. We also discuss clinical trial results to date, and ongoing studies. Furthermore, we discuss novel approaches for the enhancement of MSC based cardiac regeneration, such as genetic modification. Stem Cells Translational Medicine 2018;7:543–550

Lactate is now recognized as an important intermediate in brain metabolism, but its role is still under investigation. In this work we mapped the distribution of lactate and bicarbonate produced from intravenously injected 13C-pyruvate over the whole brain using a new imaging method, hyperpolarized 13C MRI (N = 14, ages 23 to 77). Segmenting the 13C-lactate images into brain atlas regions revealed a pattern of lactate that was preserved across individuals. Higher lactate signal was observed in cortical grey matter compared to white matter and was highest in the precuneus, cuneus and lingual gyrus. Bicarbonate signal, indicating flux of [1–13C]pyruvate into the TCA cycle, also displayed consistent spatial distribution. One-way ANOVA to test for significant differences in lactate among atlas regions gave F = 87.6 and p < 10−6. This report of a “lactate topography” in the human brain and its consistent pattern is evidence of region-specific lactate biology that is preserved across individuals. [Display omitted] •Hyperpolarized 13C MRI was used to acquire human brain images in control subjects.•13C-lactate images were segmented into brain atlas regions.•The 13C-lactate topography was found to be consistent across individuals.•The preserved pattern provides evidence of region-specific lactate biology.

Inflammation promotes adverse ventricular remodeling, a common antecedent of heart failure. Here, we set out to determine how inflammatory cells affect cardiomyocytes in the remodeling heart. Pathogenic cardiac macrophages induced an IFN response in cardiomyocytes, characterized by upregulation of the ubiquitin-like protein IFN-stimulated gene 15 (ISG15), which posttranslationally modifies its targets through a process termed ISGylation. Cardiac ISG15 is controlled by type I IFN signaling, and ISG15 or ISGylation is upregulated in mice with transverse aortic constriction or infused with angiotensin II; rats with uninephrectomy and DOCA-salt, or pulmonary artery banding; cardiomyocytes exposed to IFNs or CD4+ T cell-conditioned medium; and ventricular tissue of humans with nonischemic cardiomyopathy. By nanoscale liquid chromatography-tandem mass spectrometry, we identified the myofibrillar protein filamin-C as an ISGylation target. ISG15 deficiency preserved cardiac function in mice with transverse aortic constriction and led to improved recovery of mouse hearts ex vivo. Metabolomics revealed that ISG15 regulates cardiac amino acid metabolism, whereas ISG15 deficiency prevented misfolded filamin-C accumulation and induced cardiomyocyte autophagy. In sum, ISG15 upregulation is a feature of pathological ventricular remodeling, and protein ISGylation is an inflammation-induced posttranslational modification that may contribute to heart failure development by altering cardiomyocyte protein turnover.

Cardiac fibrosis is a common finding that is associated with the progression of heart failure (HF) and impacts all chambers of the heart. Despite intense research, the treatment of HF has primarily focused upon strategies to prevent cardiomyocyte remodeling, and there are no targeted antifibrotic strategies available to reverse cardiac fibrosis. Cardiac fibrosis is defined as an accumulation of extracellular matrix (ECM) proteins which stiffen the myocardium resulting in the deterioration cardiac function. This occurs in response to a wide range of mechanical and biochemical signals. Integrins are transmembrane cell adhesion receptors, that integrate signaling between cardiac fibroblasts and cardiomyocytes with the ECM by the communication of mechanical stress signals. Integrins play an important role in the development of pathological ECM deposition. This review will discuss the role of integrins in mechano-transduced cardiac fibrosis in response to disease throughout the myocardium. This review will also demonstrate the important role of integrins as both initiators of the fibrotic response, and modulators of fibrosis through their effect on cardiac fibroblast physiology across the various heart chambers.

Abstract Background and aims Anthracyclines can cause cancer therapy-related cardiac dysfunction (CTRCD). We aimed to assess whether statins prevent decline in left ventricular ejection fraction (LVEF) in anthracycline-treated patients at increased risk for CTRCD. Methods In this multicenter double-blinded, placebo-controlled trial, patients with cancer at increased risk of anthracycline-related CTRCD (per ASCO guidelines) were randomly assigned to atorvastatin 40 mg or placebo once-daily. Cardiovascular magnetic resonance (CMR) imaging was performed before and within 4 weeks after anthracyclines. Blood biomarkers were measured at every cycle. The primary outcome was post-anthracycline LVEF, adjusted for baseline. CTRCD was defined as a fall in LVEF by >10% to <53%. Secondary endpoints included left ventricular (LV) volumes, CTRCD, CMR tissue characterization, high sensitivity troponin I (hsTnI), and B-type natriuretic peptide (BNP). Results We randomized 112 patients (56.9 ± 13.6 years, 87 female, and 73 with breast cancer): 54 to atorvastatin and 58 to placebo. Post-anthracycline CMR was performed 22 (13–27) days from last anthracycline dose. Post-anthracycline LVEF did not differ between the atorvastatin and placebo groups (57.3 ± 5.8% and 55.9 ± 7.4%, respectively) when adjusted for baseline LVEF (P = 0.34). There were no significant between-group differences in post-anthracycline LV end-diastolic (P = 0.20) or end-systolic volume (P = 0.12), CMR myocardial edema and/or fibrosis (P = 0.06–0.47), or peak hsTnI (P ≥ 0.99) and BNP (P = 0.23). CTRCD incidence was similar (4% versus 4%, P ≥ 0.99). There was no difference in adverse events. Conclusions In patients at increased risk of CTRCD, primary prevention with atorvastatin during anthracycline therapy did not ameliorate early LVEF decline, LV remodeling, CTRCD, change in serum cardiac biomarkers, or CMR myocardial tissue changes. Trial registration NCT03186404. Graphical Abstract Graphical Abstract Summary of study enrollment, assessments, and outcomes. Randomized patients had cardiovascular magnetic resonance imaging (CMR) pre- and 72 (63–122) days post-anthracycline initiation / 22 (13–27) days post last dose of anthracycline. The stethoscopes and blood tubes reflect repeated clinical and biomarker assessment after every anthracycline cycle.

Background Type 2 diabetes (T2D) is associated with coronary microvascular dysfunction, which is thought to contribute to compromised diastolic function, ultimately culminating in heart failure with preserved ejection fraction (HFpEF). The molecular mechanisms remain incompletely understood, and no early diagnostics are available. We sought to gain insight into biomarkers and potential mechanisms of microvascular dysfunction in obese mouse ( db/db ) and lean rat (Goto-Kakizaki) pre-clinical models of T2D-associated diastolic dysfunction. Methods The microRNA (miRNA) content of circulating extracellular vesicles (EVs) was assessed in T2D models to identify biomarkers of coronary microvascular dysfunction/rarefaction. The potential source of circulating EV-encapsulated miRNAs was determined, and the mechanisms of induction and the function of candidate miRNAs were assessed in endothelial cells (ECs). Results We found an increase in miR-30d-5p and miR-30e-5p in circulating EVs that coincided with indices of coronary microvascular EC dysfunction (i.e., markers of oxidative stress, DNA damage/senescence) and rarefaction, and preceded echocardiographic evidence of diastolic dysfunction. These miRNAs may serve as biomarkers of coronary microvascular dysfunction as they are upregulated in ECs of the left ventricle of the heart, but not other organs, in db/db mice. Furthermore, the miR-30 family is secreted in EVs from senescent ECs in culture, and ECs with senescent-like characteristics are present in the db/db heart. Assessment of miR-30 target pathways revealed a network of genes involved in fatty acid biosynthesis and metabolism. Over-expression of miR-30e in cultured ECs increased fatty acid β-oxidation and the production of reactive oxygen species and lipid peroxidation, while inhibiting the miR-30 family decreased fatty acid β-oxidation. Additionally, miR-30e over-expression synergized with fatty acid exposure to down-regulate the expression of eNOS, a key regulator of microvascular and cardiomyocyte function. Finally, knock-down of the miR-30 family in db/db mice decreased markers of oxidative stress and DNA damage/senescence in the microvascular endothelium. Conclusions MiR-30d/e represent early biomarkers and potential therapeutic targets that are indicative of the development of diastolic dysfunction and may reflect altered EC fatty acid metabolism and microvascular dysfunction in the diabetic heart.

Background The 2022 Canadian Cardiovascular Society (CCS) cardiorenal guideline provided clinical recommendations on sodium-glucose co-transport 2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP-1RA) use. Since then, additional trials of relevance for SGLT2i have been published. This update re-evaluates the clinical recommendations for using SGLTi and their indirect comparison with existing evidence on GLP-1RA as compared to the standard of care to reduce cardiorenal morbidity and mortality. Methods We updated our existing search and screening of the literature from September 2021 to April 2023 for randomized controlled trials of SGLT2i and GLP-1RA with placebo control. We conducted risk of bias assessment, data extraction and updated our meta-analysis of studies with similar interventions and components. The certainty of the evidence was determined using GRADE. Results Evidence from three new trials and additional results from an updated existing trial on SGLT2i met our inclusion criteria after an updated search. Across all the included studies, the total sample size was 151,023 adults, with 90,943 in SGLT2i trials and 60,080 in GLP-1 RA trials. The mean age ranged from 59.9 to 68.4 years. Compared with standard care, the use of SGLT2i and GLP-1 RA showed significant reductions in the outcomes of cardiovascular (CV) mortality (14% & 13%), any-cause mortality (12% & 12%), major adverse CV events (MACE) (11% & 14%), heart failure (HF) hospitalization (30% & 9%), CV death or HF hospitalization (23% & 11%), and kidney composite outcome (32% & 22%). In participants with T2D, both classes demonstrated significant cardiorenal protection. But, only GLP-1RA showed a reduction in non-fatal stroke (16%) and only SGLT2i showed a reduction in HF hospitalization (30%) in this population of people living with T2D. Conclusions This updated and comprehensive meta-analysis substantiates and strengthens the clinical recommendations of the CCS cardiorenal guidelines.

Background and aims Sodium–glucose linked cotransporter-2 (SGLT2) inhibitors reduce the likelihood of hospitalization for heart failure and cardiovascular death in both diabetic and non-diabetic individuals with reduced ejection fraction heart failure. Because SGLT2 inhibitors lead to volume contraction with reductions in both preload and afterload, these load-dependent factors are thought to be major contributors to the cardioprotective effects of the drug class. Beyond these effects, we hypothesized that SGLT2 inhibitors may also improve intrinsic cardiac function, independent of loading conditions. Methods Pressure–volume (P–V) relationship analysis was used to elucidate changes in intrinsic cardiac function, independent of alterations in loading conditions in animals with experimental myocardial infarction, a well-established model of HFrEF. Ten-week old, non-diabetic Fischer F344 rats underwent ligation of the left anterior descending (LAD) coronary artery to induce myocardial infarction (MI) of the left ventricle (LV). Following confirmation of infarct size with echocardiography 1-week post MI, animals were randomized to receive vehicle, or the SGLT2 inhibitor, empagliflozin. Cardiac function was assessed by conductance catheterization just prior to termination 6 weeks later. Results The circumferential extent of MI in animals that were subsequently randomized to vehicle or empagliflozin groups was similar. Empagliflozin did not affect fractional shortening (FS) as assessed by echocardiography. In contrast, load-insensitive measures of cardiac function were substantially improved with empagliflozin. Load-independent measures of cardiac contractility, preload recruitable stroke work (PRSW) and end-systolic pressure volume relationship (ESPVR) were higher in rats that had received empagliflozin. Consistent with enhanced cardiac performance in the heart failure setting, systolic blood pressure (SBP) was higher in rats that had received empagliflozin despite its diuretic effects. A trend to improved diastolic function, as evidenced by reduction in left ventricular end-diastolic pressure (LVEDP) was also seen with empagliflozin. MI animals treated with vehicle demonstrated myocyte hypertrophy, interstitial fibrosis and evidence for changes in key calcium handling proteins (all p < 0.05) that were not affected by empagliflozin therapy. Conclusion Empagliflozin therapy improves cardiac function independent of loading conditions. These findings suggest that its salutary effects are, at least in part, due to actions beyond a direct effect of reduced preload and afterload.

Background Patients with diabetes are at a high risk for developing cardiac dysfunction in the absence of coronary artery disease or hypertension, a condition known as diabetic cardiomyopathy. Contributing to heart failure is the presence of diabetic kidney disease. The Goto-Kakizaki (GK) rat is a non-obese, non-hypertensive model of type 2 diabetes that, like humans, shares a susceptibility locus on chromosome 10. Herein, we perform a detailed analysis of cardio-renal remodeling and response to renin angiotensin system blockade in GK rats to ascertain the validity of this model for further insights into disease pathogenesis. Methods Study 1: Male GK rats along with age matched Wistar control animals underwent longitudinal assessment of cardiac and renal function for 32 weeks (total age 48 weeks). Animals underwent regular echocardiography every 4 weeks and at sacrifice, early (~24 weeks) and late (~48 weeks) timepoints, along with pressure volume loop analysis. Histological and molecular characteristics were determined using standard techniques. Study 2: the effect of renin angiotensin system (RAS) blockade upon cardiac and renal function was assessed in GK rats. Finally, proteomic studies were conducted in vivo and in vitro to identify novel pathways involved in remodeling responses. Results GK rats developed hyperglycaemia by 12 weeks of age (p<0.01 c/w Wistar controls). Echocardiographic assessment of cardiac function demonstrated preserved systolic function by 48 weeks of age. Invasive studies demonstrated left ventricular hypertrophy, pulmonary congestion and impaired diastolic function. Renal function was preserved with evidence of hyperfiltration. Cardiac histological analysis demonstrated myocyte hypertrophy (p<0.05) with evidence of significant interstitial fibrosis (p<0.05). RT qPCR demonstrated activation of the fetal gene program, consistent with cellular hypertrophy. RAS blockade resulted in a reduction blood pressure(P<0.05) cardiac interstitial fibrosis (p<0.05) and activation of fetal gene program. No significant change on either systolic or diastolic function was observed, along with minimal impact upon renal structure or function. Proteomic studies demonstrated significant changes in proteins involved in oxidative phosp4horylation, mitochondrial dysfunction, beta-oxidation, and PI3K/Akt signalling (all p<0.05). Further, similar changes were observed in both LV samples from GK rats and H9C2 cells incubated in high glucose media. Conclusion By 48 weeks of age, the diabetic GK rat demonstrates evidence of preserved systolic function and impaired relaxation, along with cardiac hypertrophy, in the presence of hyperfiltration and elevated protein excretion. These findings suggest the GK rat demonstrates some, but not all features of diabetes induced \"cardiorenal\" syndrome. This has implications for the use of this model to assess preclinical strategies to treat cardiorenal disease.

Background Inhibiting both type 1 and 2 sodium–glucose linked cotransporter (SGLT1/2) offers the potential to not only increase glucosuria beyond that seen with selective SGLT2 inhibition alone but to reduce glucose absorption from the gut and to thereby also stimulate glucagon-like peptide 1 secretion. However, beyond the kidney and gut, SGLT1 is expressed in a range of other organs particularly the heart where it potentially assists GLUT-mediated glucose transport. Since cardiac myocytes become more reliant on glucose as a fuel source in the setting of stress, the present study sought to compare the effects of dual SGLT1/2 inhibition with selective SGLT2 inhibition in the normal and diseased heart. Methods Fischer F344 rats underwent ligation of the left anterior descending coronary artery or sham ligation before being randomized to receive the dual SGLT1/2 inhibitor, T-1095, the selective SGLT2 inhibitor, dapagliflozin or vehicle. In addition to measuring laboratory parameters, animals also underwent echocardiography and cardiac catheterization to assess systolic and diastolic function in detail. Results When compared with rats that had received either vehicle or dapagliflozin, T-1095 exacerbated cardiac dysfunction in the post myocardial infarction setting. In addition to higher lung weights, T-1095 treated rats had evidence of worsened systolic function with lower ejection fractions and reduction in the rate of left ventricle pressure rise in early systole (dP/dt max ). Diastolic function was also worse in animals that had received T-1095 with prolongation of the time constant for isovolumic-pressure decline (Tau) and an increase in the end-diastolic pressure volume relationship, indices of the active, energy-dependent and passive phases of cardiac relaxation. Conclusions The exacerbation of post myocardial infarction cardiac dysfunction with T-1095 in the experimental setting suggests the need for caution with the use of dual SGLT1/2 inhibitors in humans.