Pathological Cardiac Remodeling Research Articles

Identification of Adamts4 as a novel adult cardiac injury biomarker with therapeutic implications in patients with cardiac injuries

Pathological cardiac remodeling as an aftermath of a severe cardiac injury can lead to ventricular dysfunction and subsequent heart failure. Adamts4, a metalloproteinase, and disintegrin with thrombospondin-like motif, involved in the turnover of certain extracellular matrix molecules and pathogenesis of osteoarthritis, also plays a role in cardiac remodeling although little is presently known about its expression and function in the heart. Here, we have investigated the dynamic expression pattern of Adamts4 during cardiogenesis and also in the adult heart. To our surprise, adult cardiac injury reactivated Adamts4 expression concomitant with fibrosis induction. To better understand the mechanism, cultured H9c2 cardiomyocyte cells were subjected to ROS injury and Hypoxia. Moreover, through combinatorial treatment with SB431542 (an inhibitor of Tgf-β1), and Adamts4 siRNA mediated gene knockdown, we were able to decipher a regulatory hierarchy to the signal cascade being at the heart of Tgf-β regulation. Besides the hallmark expression of Adamts4 and Tgf-β1, expression of other fibrosis-related markers like Collagen-III, alpha-SMA and Periostin were also assessed. Finally, increased levels of Adamts4 and alpha-SMA proteins in cardiac patients also resonated well with our animal and cell culture studies. Overall, in this study, we highlight, Adamts4 as a novel biomarker of adult cardiac injury.

Tandem Mass Tagging Based Identification of Proteome Signatures for Reductive Stress Cardiomyopathy.

Nuclear factor erythroid 2-related factor 2 (NRF2), a redox sensor, is vital for cellular redox homeostasis. We reported that transgenic mice expressing constitutively active Nrf2 (CaNrf2-TG) exhibit reductive stress (RS). In this study, we identified novel protein signature for RS-induced cardiomyopathy using Tandem Mass Tag (TMT) proteomic analysis in heart tissues of TG (CaNrf2-TG) mice at 6–7 months of age. A total of 1,105 proteins were extracted from 22,544 spectra. About 560 proteins were differentially expressed in TG vs. NTg hearts, indicating a global impact of RS on the myocardial proteome. Over 32 proteins were significantly altered in response to RS -20 were upregulated and 12 were downregulated in the hearts of TG vs. NTg mice, suggesting that these proteins could be putative signatures of RS. Scaffold analysis revealed a clear distinction between TG vs. NTg hearts. The majority of the differentially expressed proteins (DEPs) that were significantly altered in RS mice were found to be involved in stress related pathways such as antioxidants, NADPH, protein quality control, etc. Interestingly, proteins that were involved in mitochondrial respiration, lipophagy and cardiac rhythm were dramatically decreased in TG hearts. Of note, we identified the glutathione family of proteins as the significantly changed subset of the proteome in TG heart. Surprisingly, our comparative analysis of NGS based transcriptome and TMT-proteome indicated that ~50% of the altered proteins in TG myocardium was found to be negatively correlated with their transcript levels. In association with the altered proteome the TG mice displayed pathological cardiac remodeling.

CCL17 acts as a novel therapeutic target in pathological cardiac hypertrophy and heart failure.

Circulating proteomic signatures of age are closely associated with aging and age-related diseases; however, the utility of changes in secreted proteins in identifying therapeutic targets for diseases remains unclear. Serum proteomic profiling of an age-stratified healthy population and further community-based cohort together with heart failure patients study demonstrated that circulating C-C motif chemokine ligand 17 (CCL17) level increased with age and correlated with cardiac dysfunction. Subsequent animal experiments further revealed that Ccll7-KO significantly repressed aging and angiotensin II (Ang II)-induced cardiac hypertrophy and fibrosis, accompanied by the plasticity and differentiation of T cell subsets. Furthermore, the therapeutic administration of an anti-CCL17 neutralizing antibody inhibited Ang II-induced pathological cardiac remodeling. Our findings reveal that chemokine CCL17 is identifiable as a novel therapeutic target in age-related and Ang II-induced pathological cardiac hypertrophy and heart failure.

Pyruvate Kinase M2 Protects Heart from Pressure Overload-Induced Heart Failure by Phosphorylating RAC1.

BackgroundHeart failure, caused by sustained pressure overload, remains a major public health problem. PKM (pyruvate kinase M) acts as a rate‐limiting enzyme of glycolysis. PKM2 (pyruvate kinase M2), an alternative splicing product of PKM, plays complex roles in various biological processes and diseases. However, the role of PKM2 in the development of heart failure remains unknown.Methods and ResultsCardiomyocyte‐specific Pkm2 knockout mice were generated by crossing the floxed Pkm2 mice with α‐MHC (myosin heavy chain)‐Cre transgenic mice, and cardiac specific Pkm2 overexpression mice were established by injecting adeno‐associated virus serotype 9 system. The results showed that cardiomyocyte‐specific Pkm2 deletion resulted in significant deterioration of cardiac functions under pressure overload, whereas Pkm2 overexpression mitigated transverse aortic constriction‐induced cardiac hypertrophy and improved heart functions. Mechanistically, we demonstrated that PKM2 acted as a protein kinase rather than a pyruvate kinase, which inhibited the activation of RAC1 (rho family, small GTP binding protein)‐MAPK (mitogen‐activated protein kinase) signaling pathway by phosphorylating RAC1 in the progress of heart failure. In addition, blockade of RAC1 through NSC23766, a specific RAC1 inhibitor, attenuated pathological cardiac remodeling in Pkm2 deficiency mice subjected to transverse aortic constriction.ConclusionsThis study revealed that PKM2 attenuated overload‐induced pathological cardiac hypertrophy and heart failure, which provides an attractive target for the prevention and treatment of cardiomyopathies.

Myocardial mesostructure and mesofunction.

The complex and highly organized structural arrangement of some five billion cardiomyocytes directs the coordinated electrical activity and mechanical contraction of the human heart. The characteristic transmural change in cardiomyocyte orientation underlies base-to-apex shortening, circumferential shortening, and left ventricular torsion during contraction. Individual cardiomyocytes shorten ∼15% and increase in diameter ∼8%. Remarkably, however, the left ventricular wall thickens by up to 30-40%. To accommodate this, the myocardium must undergo significant structural rearrangement during contraction. At the mesoscale, collections of cardiomyocytes are organized into sheetlets, and sheetlet shear is the fundamental mechanism of rearrangement that produces wall thickening. Herein, we review the histological and physiological studies of myocardial mesostructure that have established the sheetlet shear model of wall thickening. Recent developments in tissue clearing techniques allow for imaging of whole hearts at the cellular scale, whereas magnetic resonance imaging (MRI) and computed tomography (CT) can image the myocardium at the mesoscale (100 µm to 1 mm) to resolve cardiomyocyte orientation and organization. Through histology, cardiac diffusion tensor imaging (DTI), and other modalities, mesostructural sheetlets have been confirmed in both animal and human hearts. Recent in vivo cardiac DTI methods have measured reorientation of sheetlets during the cardiac cycle. We also examine the role of pathological cardiac remodeling on sheetlet organization and reorientation, and the impact this has on ventricular function and dysfunction. We also review the unresolved mesostructural questions and challenges that may direct future work in the field.

Tabersonine attenuates Angiotensin II-induced cardiac remodeling and dysfunction through targeting TAK1 and inhibiting TAK1-mediated cardiac inflammation

BackgroundAngiotensin II (Ang II)-induced cardiac inflammation contribute to pathological cardiac remodeling and hypertensive heart failure (HF). Tabersonine (Tab) is an indole alkaloid mainly isolated from Catharanthus roseus and exhibits anti-inflammatory activity in various systems. However, the role of Tab in hypertensive HF and its molecular targets remains unknown. Hypothesis/purposeWe aimed to investigate potential cardioprotective effects and mechanism of Tab against Ang II-induced cardiac injuries. MethodsC57BL/6 mice were administered Ang II (at 1000 ng/kg/min) by micro-osmotic pump infusion for 30 days to develop hypertensive HF. Tab at 20 and 40 mg/kg/day was administered during the last 2 weeks to elucidate the cardioprotective properties. Cultured cardiomyocyte-like H9c2 cells and rat primary cardiomyocytes were used for mechanistic studies of Tab. ResultsWe demonstrate for the first time that Tab provides protection against Ang II–induced cardiac dysfunction in mice, associated with reduced cardiac inflammation and fibrosis. Mechanistically, we show that Tab may interacts with TAK1 to inhibit Ang II-induced TAK1 ubiquitination and phosphorylation. Disruption of TAK1 activation by Tab blocked downstream NF-κB and JNK/P38 MAPK signaling activation and decreased cardiac inflammation and fibrosis both in vitro and in vivo. TAK1 knockdown also blocked Ang II-induced cardiomyocytes injuries and prevented the innately pharmacological effects of Tab. ConclusionOur results indicate that Tab protects hearts against Ang II-mediated injuries through targeting TAK1 and inhibiting TAK1-mediated inflammatory cascade and response. Thus, Tab may be a potential therapeutic candidate for hypertensive HF.

FBP2-A New Player in Regulation of Motility of Mitochondria and Stability of Microtubules in Cardiomyocytes.

Recently, we have shown that the physiological roles of a multifunctional protein fructose 1,6-bisphosphatase 2 (FBP2, also called muscle FBP) depend on the oligomeric state of the protein. Here, we present several lines of evidence that in HL-1 cardiomyocytes, a forced, chemically induced reduction in the FBP2 dimer-tetramer ratio that imitates AMP and NAD+ action and restricts FBP2-mitochondria interaction, results in an increase in Tau phosphorylation, augmentation of FBP2-Tau and FBP2-MAP1B interactions, disturbance of tubulin network, marked reduction in the speed of mitochondrial trafficking and increase in mitophagy. These results not only highlight the significance of oligomerization for the regulation of FBP2 physiological role in the cell, but they also demonstrate a novel, important cellular function of this multitasking protein—a function that might be crucial for processes that take place during physiological and pathological cardiac remodeling, and during the onset of diseases which are rooted in the destabilization of MT and/or mitochondrial network dynamics.

MO440: Intramyocardial Artery Fibrosis and Media Hypertrophy are Associated With Beta-Catenin and Calcineurin Expression in the Model of Arterial Hypertension and CKD

Abstract BACKGROUND AND AIMS Intramyocardial arteries (IA) are one of the components of pathological cardiac remodeling. We have previously shown that cardiomyocytes hypertrophy and interstitial fibrosis are accompanied by calcineurin (CaN) and β-catenin (βCat) up-regulation in the model of arterial hypertension (AH) and chronic kidney disease (AH-CKD). In this pilot study, we investigated whether IA remodeling is associated with CaN and βCat expressions in medial (MC) and adventitial (AC) cells in AH-CKD. METHOD AH-CKD was induced by 5/6 nephrectomy (5/6NE) in spontaneously hypertensive rats (SHR-NE, n = 8). Sham-operated (SO) SHR (SHR-SO, n = 8) and Wistar Kyoto rats (WKY-SO, n = 8) were controls. Systolic blood pressure (SBP), myocardial mass index (MMI), serum creatinine (Cr), FGF23, renal Klotho (rKl), IA wall thickness (WT), perivascular fibrosis (PF), number of AC, βCat-positive AC (βCat + AC) to all AC ratio, CaN and βCat expression in MC were analyzed for 2 months after 5/6NE or SO. RESULTS The cardiac remodeling indexes—SBP, MMI, WT, AC, PF, as well as FGF23, were higher and rKl was lower in SHRs vs WKY-SO and in SHR-NE versus SHR-SO (Table). The increase in WT was accompanied by MC hypertrophy (Figure 1) with cytoplasmic CaN expression (data not shown) and PF with the increase in the number of AC in SHR-SO vs WKY-SO (Table). PF, medial hypertrophy and fibrosis of IA were accompanied by the apparent expression of CaN and βCat in the MC (Figure 1), an increase in the total number of AC and the βCat + AC accumulation in AH-CKD (Table, Figure 2). CONCLUSION IA remodeling in the setting of AH and CKD seems to be associated with СаN and βCat up-regulation in medial and adventitial cells subpopulations. Further study is needed to identify the origin of CaN/βCat expressing cells and the mechanisms of their involvement in the pathology of vascular wall alterations.

Liquiritin Attenuates Pathological Cardiac Hypertrophy by Activating the PKA/LKB1/AMPK Pathway.

Background: Liquiritin (LQ) is one of the main flavonoids extracted from the roots of Glycyrrhiza spp., which are widely used in traditional Chinese medicine. Studies in both cellular and animal disease models have shown that LQ attenuates or prevents oxidative stress, inflammation, and apoptosis. However, the potential therapeutic effects of LQ on pressure overload-induced cardiac hypertrophy have not been so far explored. Therefore, we investigated the cardioprotective role of LQ and its underlying mechanisms in the aortic banding (AB)-induced cardiac hypertrophy mouse model. Methods and Results: Starting 3 days after AB surgery, LQ (80 mg/kg/day) was administered daily over 4 weeks. Echocardiography and pressure-volume loop analysis indicated that LQ treatment markedly improved hypertrophy-related cardiac dysfunction. Moreover, hematoxylin and eosin, picrosirius red, and TUNEL staining showed that LQ significantly inhibited cardiomyocyte hypertrophy, interstitial fibrosis, and apoptosis. Western blot assays further showed that LQ activated LKB1/AMPKα2/ACC signaling and inhibited mTORC1 phosphorylation in cardiomyocytes. Notably, LQ treatment failed to prevent cardiac dysfunction, hypertrophy, and fibrosis in AMPKα2 knockout (AMPKα2−/−) mice. However, LQ still induced LKB1 phosphorylation in AMPKα2−/− mouse hearts. In vitro experiments further demonstrated that LQ inhibited Ang II-induced hypertrophy in neonatal rat cardiomyocytes (NRCMs) by increasing cAMP levels and PKA activity. Supporting the central involvement of the cAMP/PKA/LKB1/AMPKα2 signaling pathway in the cardioprotective effects of LQ, inhibition of Ang II-induced hypertrophy and induction of LKB1 and AMPKα phosphorylation were no longer observed after inhibiting PKA activity. Conclusion: This study revealed that LQ alleviates pressure overload-induced cardiac hypertrophy in vivo and inhibits Ang II-induced cardiomyocyte hypertrophy in vitro via activating cAMP/PKA/LKB1/AMPKα2 signaling. These findings suggest that LQ might be a valuable adjunct to therapeutic approaches for treating pathological cardiac remodeling.

Sclerostin aggravates cardiac remodeling after myocardial infarction by inhibition of Wnt/β-catenin signaling pathway.

BackgroundThe serum levels of sclerostin (SOST) are significant elevated in patients with pathological cardiac remodeling after myocardial infarction (MI). However, the mechanisms of SOST in cardiac remodeling remain largely uncharacterized.MethodsCollecting patients with MI who presented with or without left ventricular (LV) remodeling, we investigated differences in SOST expression. The influence of overexpression and silenced of SOST on the angiogenesis of cardiac microvascular endothelial cells (CMECs) was explored through in vitro experiments, and the impact of SOST on Wnt signaling marker proteins was examined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blot. Finally, we observed the effects of SOST on cardiac function and morphology in mice MI model, and verified the role of the Wnt signaling marker proteins in vivo.ResultsSerum SOST was significantly increased in patients with cardiac remodeling. Increased SOST expression was also observed in the infarcted hearts of C57BL/6 mice that underwent ligation of the left anterior descending branch of the coronary artery to induce MI. Furthermore, loss and gain of function experiments were conducted to investigate the role of SOST in post-infarct cardiac remodeling in vivo and in vitro. Overexpression of SOST promoted the proliferation and migration of cardiac fibroblasts (CFs), and inhibited angiogenesis of CMECs. In addition, overexpressing SOST in mice significantly deteriorated the post-infarct cardiac remodeling, as shown by the increased LV end systolic and end diastolic dimensions, decreased ejection fraction, and increased myocyte cross-section area and myocardial fibrosis. However, suppressing SOST expression showed the opposite results. The expression of Wnt signaling marker proteins was inhibited after overexpression of SOST, and enhanced after suppression of SOST in vivo and in vitro, suggesting involvement of the Wnt signaling pathway.ConclusionsThe present study demonstrated that SOST aggravates post-infarct pathological myocardial remodeling by inhibiting angiogenesis of CMECs while promoting the proliferation of CFs, and this may be mediated by the Wnt signaling pathway. These results suggested that SOST might act as a biomarker to predict detrimental postinfarct cardiac remodeling, and may be a potential therapeutic target for the treatment of MI.

Computational Modeling using Artificial Neural Networks Identifies Chamber‐Specific Predictors of Cardiac Collagen Content in Ovariectomized and Aortic‐Banded Yucatan Mini‐Swine

ObjectiveHeart failure with preserved ejection fraction (HFpEF) is a disease associated with significant clinical pathophysiological heterogeneity in which maladaptive cardiac fibrosis, in both the right and left ventricles of the heart, plays a unique role in the manifestation of disease. The prevalence of HFpEF is greater in postmenopausal women with hypertension. Thus, the purpose of this study was to identify variables predictive of cardiac fibrosis with the potential to help elucidate new biomarkers indicative of the pathological diffuse fibrotic remodeling often observed in HFpEF. Given significant sex disparities noted in HFpEF prevalence, biological inputs were measure in both the right and left ventricles of a pre‐clinical female Yucatan mini‐swine model of chronic pressure overload‐induced heart failure. Predictors of total left ventricular collagen content were identified and assessed for accuracy.HypothesisArtificial neural networks can identify molecular markers involved in the bioregulation of the extracellular matrix (ECM) that predict total collagen content in the left ventricle with >90% accuracy.Methods98 biological features measured in the right and left ventricle including mRNA, protein, and activity measurements of estrogen/progesterone receptors, ECM regulatory biomarkers including matrix metalloproteinases (MMP’s) and their tissue‐inhibitors (TIMP’s), several aspects of the mitogen‐activated protein kinase signaling pathway including ERK, JNK, and dual specificity phosphatases, and ECM structural components (e.g. collagen, fibronectin) were analyzed in 24 female Yucatan mini‐swine. Variables were pooled and assessed comprehensively from animals divided into 4 groups: control, ovariectomized, aortic‐banded, and aortic‐banded with ovariectomy (n=5‐7/group). Missing data were mean imputed and the min‐max normalization method was used. Linear regression models were used to identify variables with the strongest relationships to left ventricular total collagen content. Identified molecular predictors were used in an artificial neural network model using stratified 4‐fold cross validation with logistic activation function, one hidden layer, and 4 nodes.ResultsIn the left ventricle, TIMP2 protein and mRNA, MMP2 mRNA, and fibronectin protein and mRNA were used in the artificial neural network. In the right ventricle, MMP9 activity/abundance (zymography) and total collagen content were included in the computational analysis. Together, these variables could predict total collagen content in the left ventricle with 92.08 % accuracy.ConclusionAnalysis of cardiac fibrosis by artificial neural network identified seven bi‐ventricular molecular features with a high capacity to predict total collagen content in the left ventricle. These results highlight their potential as important biomarkers of pathological cardiac fibrotic remodeling in a preclinical setting of chronic pressure overload‐induced heart failure with potential relevance to HFpEF.

Inhibition of activin A receptor signalling attenuates age-related pathological cardiac remodelling

ABSTRACTIn the heart, ageing is associated with DNA damage, oxidative stress, fibrosis and activation of the activin signalling pathway, leading to cardiac dysfunction. The cardiac effects of activin signalling blockade in progeria are unknown. This study investigated the cardiac effects of progeria induced by attenuated levels of Ercc1, which is required for DNA excision and repair, and the impact of activin signalling blockade using a soluble activin receptor type IIB (sActRIIB). DNA damage and oxidative stress were significantly increased in Ercc1Δ/− hearts, but were reduced by sActRIIB treatment. sActRIIB treatment improved cardiac systolic function and induced cardiomyocyte hypertrophy in Ercc1Δ/− hearts. RNA-sequencing analysis showed that in Ercc1Δ/− hearts, there was an increase in pro-oxidant and a decrease in antioxidant gene expression, whereas sActRIIB treatment reversed this effect. Ercc1Δ/− hearts also expressed higher levels of anti-hypertrophic genes and decreased levels of pro-hypertrophic ones, which were also reversed by sActRIIB treatment. These results show for the first time that inhibition of activin A receptor signalling attenuates cardiac dysfunction, pathological tissue remodelling and gene expression in Ercc1-deficient mice and presents a potentially novel therapeutic target for heart diseases.

Investigating the Therapeutic Potential of Cdk8 Small Molecule Inhibitors to Prevent Pathological Cardiac Remodeling and Heart Failure

Pathological cardiac hypertrophy represents a major risk factor for heart failure (HF). Cardiac hypertrophic responses are coordinated in part through altered transcriptional dynamics involving chromatin structure and accessibility, transcription factor (TF) activation, and enhancer utilization. Mediator is a multiprotein complex that integrates signal‐dependent TFs with basal transcriptional machinery to regulate downstream gene expression. Cyclin‐dependent kinase 8 (Cdk8) is a Mediator kinase demonstrated to have a complex role in transcription regulation, driving both transcription activation and inhibition in context‐specific ways. Previous studies have demonstrated that Cdk8 protein expression is increased in human and mouse HF. Cardiomyocyte‐specific Cdk8 overexpression leads to eccentric cardiac hypertrophy consistent with HF, suggesting that Cdk8 activity may play a significant role in the progression of HF. To investigate the therapeutic potential in regulating Cdk8 activity, we used Cdk8 selective inhibitors SenexinA and CCT251545 in an in vitro neonatal rat cardiomyocyte hypertrophy model, resulting in altered regulation of hypertrophic transcriptional programs and blunted cardiomyocyte hypertrophy. To further assess Cdk8 kinase activity in regulating hypertrophic responses, Cdk8 inhibitor CCT251545 was used in an in vivo angiotensin II‐induced hypertensive mouse model. It was hypothesized that Cdk8 inhibition by CCT251545 in vivo would lead to reduced hypertrophic responses. Results indicate that CCT251545 is effective at inhibiting Cdk8 activity, leading to blunted hypertrophic responses with altered gene expression. These studies demonstrate a role for Cdk8 activity in transcriptional regulation of genes associated with pathological cardiac hypertrophy, which can ultimately lead to heart failure.

A novel and important role of UFM1‐binding protein 1 (UFBP1) in the regulation of ER and cardiac homeostasis

Protein modifications by ubiquitin and ubiquitin‐like proteins are emerging as an important mechanism regulating heart function. UFM1 (ubiquitin‐fold modifier 1) is a novel ubiquitin‐like protein that modifies protein targets via UFM1‐specific conjugation enzymes. Dysregulation of UFM1 modification, termed ufmylation, has been linked to multiple human diseases but its importance in the heart remains unclear. We have previously reported that ufmylation is upregulated in compensated, hypertrophic mouse hearts but decreased in failing human hearts. Inhibition of ufmylation by targeted ablation of the E3 UFM1 ligase 1 (UFL1) in mouse hearts resulted in dilated cardiomyopathy during ageing and increased the propensity to heart failure in response to hemodynamic stress. However, how ufmylation exerts its cardioprotective effect remains unclear. Here, we report that UFBP1 (UFM1 binding protein 1), an ER‐resident ufmylation target, is an important downstream effector of ufmylation in the heart. While deletion of UFBP1 in mouse hearts has no impact on ufmylation, the knockout (KO) mice developed dilated cardiomyopathy at resting condition, as indicated by left ventricular wall thinning, chamber dilatation and significantly decreased cardiac contractility at 6 months of age. Moreover, loss of UFBP1 exacerbated pressure overload‐induced cardiac remodeling and dysfunction, recapitulating multiple aspects of the phenotypes of UFL1‐deficient hearts. Mechanistically, UFL1 controls the expression of UFBP1. Depletion of both UFL1 and UFBP1 in cultured cardiomyocytes aggravated ER stress‐induced cell injury. Furthermore, excess ER stress is implicated in UFBP1KO hearts and is aggravated with the progression of cardiomyopathy. Interestingly, ER stress inducers upregulated the expression of ufmylation pathway components at both transcript and protein levels in cultured cardiomyocytes and mouse hearts, indicating an intimate cross‐talk between ufmylation and ER stress. Collectively, our data identify a novel UFM1‐UFL1‐UFBP1 axis in constraining pathological cardiac remodeling and maintaining ER homeostasis.

Nutritional Predictors of Cardiovascular Risk in Patients after Kidney Transplantation-Pilot Study

Asymmetric dimethylarginine (ADMA) is a marker of endothelial damage. Research confirms the association of ADMA with an increased cardiovascular risk (CVR) among kidney transplant recipients (KTRs). Additionally, increased circulating levels of fibroblast growth factor 23 (FGF-23) are associated with pathological cardiac remodeling and vascular alterations. The aim of the study is the analysis of the relationship between ADMA, FGF-23, nutritional, biochemical parameters in healthy subjects and KTRs. 46 KTRs and 23 healthy volunteers at mean age of 50.8 ± 15.4 and 62.5 ± 10.7 years were enrolled. The anthropometric and biochemical parameters such as ADMA, FGF-23, albumin, prealbumin were assessed. Fat tissue mass among KTRs was 30.28 ± 9.73%, lean body mass 64.5 ± 14.8%. Overweight and obesity was presented by 65.2% of recipients. Albumin level was 38.54 ± 3.80 g/L, prealbumin 27.83 ± 7.30 mg/dL and were significantly lower than in the control (p < 0.05). Patients with ADMA > 0.66 µmol/L had a lower concentration of prealbumin, albumin and increased concentration of oxidized low density lipoprotein (oxLDL), high sensitive C-reactive protein (hsCRP) and FGF-23. FGF-23 was significantly higher in patients with higher hsCRP (p < 0.05). KTRs with elevated ADMA had a longer transplantation vintage, lower eGFR and higher albuminuria. Diabetes mellitus (DM) was associated with higher levels of ADMA and FGF-23. Even in stable KTRs a relationship between inflammatory state, nutritional status, graft function and endothelial dysfunction biomarkers was observed.

Cardiac Structure and Function in Junior Athletes: A Systematic Review of Echocardiographic Studies.

In young athletes, the level of competitiveness in sports is increasing, as well as frequency and intensity of exercise training. Adaptations of the cardiac system to this increased workload imposed by exercise has not yet been studied sufficiently. In adults, studies point towards a shift from the functional athlete's heart towards pathological cardiac remodelling, with ventricular arrythmia and impaired cardiac function, that is exercise-related. This systematic review investigates cardiac adaptations to exercise in junior athletes compared to inactive controls. Three electronic databases (PubMed/Medline, ScienceDirect and Web of Science) were searched for studies assessing 2-dimensional transthoracic echocardiography (2D TTE) and 2-dimensional speckle tracking echocardiography (2D STE) parameters in junior athletes, aged 7-19 years, compared to inactive controls. Data was screened and extracted by two reviewers; study quality and risk of bias was assessed by three reviewers. Eight out of 1460 studies met all inclusion criteria, with all studies reporting results on 2D TTE and six studies reporting results on 2D STE parameters in 540 (51 girls) junior athletes and 270 (18 girls) controls. There is evidence for structural cardiac adaptations of the left ventricle and both atria in junior athletes. Results regarding left ventricular function are controversial with a tendency to improved function in dynamic exercising athletes. Left ventricular mass and relative wall thickness point towards higher values in static exercising athletes. Cardiac adaptations to exercise occur in children and adolescents. These adaptations are more pronounced in structural left ventricular parameters. Functional parameters are preserved or slightly improved in junior athletes but not impaired by exercise.

Renal denervation ameliorates cardiac metabolic remodeling in diabetic cardiomyopathy rats by suppressing renal SGLT2 expression

AbstractThis study aimed to investigate the effects of renal denervation (RDN) on diabetic cardiomyopathy (DCM) and explore the related mechanisms. Male Sprague-Dawley rats were fed high-fat chow and injected with low-dose streptozotocin to establish a DCM model. Six rats served as controls. The surviving rats were divided into three groups: control group, DCM group and DCM + RDN group. RDN surgery was performed in the fifth week. At the end of the experiment, all rats were subjected to 18F-FDG PET/CT and metabolic cage studies. Cardiac function and structure were evaluated by echocardiography and histology. Myocardial substrate metabolism and mitochondrial function were assessed by multiple methods. In the 13th week, the DCM rats exhibited cardiac hypertrophy and interstitial fibrosis accompanied by diastolic dysfunction. RDN ameliorated DCM-induced cardiac dysfunction (E/A ratio: RDN 1.07 ± 0.18 vs. DCM 0.93 ± 0.12, P < 0.05; E/E' ratio: RDN 10.74 ± 2.48 vs. DCM 13.25 ± 1.99, P < 0.05) and pathological remodeling (collagen volume fraction: RDN 5.05 ± 2.05% vs. DCM 10.62 ± 2.68%, P < 0.05). Abnormal myocardial metabolism in DCM rats was characterized by suppressed glucose metabolism and elevated lipid metabolism. RDN increased myocardial glucose uptake and oxidation while reducing the absorption and utilization of fatty acids. Meanwhile, DCM decreased mitochondrial ATP content, depolarized the membrane potential and inhibited the activity of respiratory chain complexes, but RDN attenuated this mitochondrial damage (ATP: RDN 30.98 ± 7.33 μmol/gprot vs. DCM 22.89 ± 5.90 μmol/gprot, P < 0.05; complexes I, III and IV activity: RDN vs. DCM, P < 0.05). Furthermore, both SGLT2 inhibitor and the combination treatment produced similar effects as RDN alone. Thus, RDN prevented DCM-induced cardiac dysfunction and pathological remodeling, which is related to the improvement of metabolic disorders and mitochondrial dysfunction.Diabetic cardiomyopathy is a serious diabetes-related cardiovascular complication, which is closely related to myocardial metabolic disorders, but there is no specific therapy currently. Renal denervation (RDN), a novel technique to remove renal sympathetic nerves, can reduce the overexpression of renal SGLT2 in diabetic rats, thereby promoting urinary glucose excretion and maintaining systemic glucose homeostasis. On this basis, RDN ameliorated diabetes-induced cardiac metabolic disorders and mitochondrial damages, ultimately preventing diabetes-induced cardiac dysfunction and pathological remodeling.

Human umbilical vein endothelial cells-derived exosomes enhance cardiac function after acute myocardial infarction by activating the PI3K/AKT signaling pathway

ABSTRACT Currently, acute myocardial infarction (AMI) is one of the leading causes of human health issues worldwide. The sudden and continuous occlusion of the coronary artery results in myocardial hypoxic-ischemic necrosis, which is accompanied by inflammatory infiltration and fibrosis, leading to pathological cardiac remodeling. Exosome-based therapy is a promising cell-free approach for repairing the ischemic myocardium. This study aimed to explore the effects and mechanism of human umbilical vein endothelial cells (HUVECs)-derived exosomes on AMI. The results indicated that the localized injection of HUVECs-derived exosomes in the infarcted area could significantly improve cardiac function in AMI mouse models. It could also ameliorate myocardial fibrosis and decrease infarct size after AMI. Additionally, HUVECs-derived exosomes had cardioprotective effects on the H9C2 cells in hypoxic culture conditions, including increased cell viability and decreased lactate dehydrogenase (LDH) release. In both the in-vivo and in-vitro experiments, HUVECs-derived exosomes could effectively inhibit cardiomyocyte apoptosis. The low expression levels of Bcl-2–associated X protein (Bax) and cleaved caspase-3, high expression levels of B-cell lymphoma 2 (Bcl-2), phosphorylated phosphatidylinositol 3-kinase (p-PI3K), and phosphorylated protein kinase B (p-AKT) were detected in AMI mouse models treated with HUVECs-derived exosomes in-vivo. In conclusion, HUVECs-derived exosomes effectively enhanced cardiac function after AMI and inhibited cardiomyocyte apoptosis, which might be regulated through the phosphatidylinositol 3-kinase (PI3K)/ protein kinase B (AKT) signaling pathway.

MOTS-c and Exercise Restore Cardiac Function by Activating of NRG1-ErbB Signaling in Diabetic Rats.

Pathologic cardiac remodeling and dysfunction are the most common complications of type 2 diabetes. Physical exercise is important in inhibiting myocardial pathologic remodeling and restoring cardiac function in diabetes. The mitochondrial-derived peptide MOTS-c has exercise-like effects by improving insulin resistance, combatting hyperglycemia, and reducing lipid accumulation. We investigated the effects and transcriptomic profiling of MOTS-c and aerobic exercise on cardiac properties in a rat model of type 2 diabetes which was induced by feeding a high fat high sugar diet combined with an injection of a low dose of streptozotocin. Both aerobic exercise and MOTS-c treatment reduced abnormalities in cardiac structure and function. Transcriptomic function enrichment analysis revealed that MOTS-c had exercise-like effects on inflammation, myocardial apoptosis, angiogenesis and endothelial cell proliferation and migration, and showed that the NRG1-ErbB4 pathway might be an important component in both MOTS-c and exercise induced attenuation of cardiac dysfunction in diabetes. Moreover, our findings suggest that MOTS-c activates NRG1-ErbB4 signaling and mimics exercise-induced cardio-protection in diabetes.

Cardiac ISL1-Interacting Protein, a Cardioprotective Factor, Inhibits the Transition From Cardiac Hypertrophy to Heart Failure.

Heart failure is characterized by the inability of the heart to pump effectively and generate proper blood circulation to meet the body’s needs; it is a devastating condition that affects more than 100 million people globally. In spite of this, little is known about the mechanisms regulating the transition from cardiac hypertrophy to heart failure. Previously, we identified a cardiomyocyte-enriched gene, CIP, which regulates cardiac homeostasis under pathological stimulation. Here, we show that the cardiac transcriptional factor GATA4 binds the promotor of CIP gene and regulates its expression. We further determined that both CIP mRNA and protein decrease in diseased human hearts. In a mouse model, induced cardiac-specific overexpression of CIP after the establishment of cardiac hypertrophy protects the heart by inhibiting disease progression toward heart failure. Transcriptome analyses revealed that the IGF, mTORC2 and TGFβ signaling pathways mediate the inhibitory function of CIP on pathologic cardiac remodeling. Our study demonstrates GATA4 as an upstream regulator of CIP gene expression in cardiomyocytes, as well as the clinical significance of CIP expression in human heart disease. More importantly, our investigation suggests CIP is a key regulator of the transition from cardiac hypertrophy to heart failure. The ability of CIP to intervene in the onset of heart failure suggests a novel therapeutic avenue of investigation for the prevention of heart disease progression.