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1.
J Cell Mol Med ; 28(8): e18334, 2024 Apr.
Article En | MEDLINE | ID: mdl-38661439

The genetic information of plasma total-exosomes originating from tissues have already proven useful to assess the severity of coronary artery diseases (CAD). However, plasma total-exosomes include multiple sub-populations secreted by various tissues. Only analysing the genetic information of plasma total-exosomes is perturbed by exosomes derived from other organs except the heart. We aim to detect early-warning biomarkers associated with heart-exosome genetic-signatures for acute myocardial infarction (AMI) by a source-tracking analysis of plasma exosome. The source-tracking of AMI plasma total-exosomes was implemented by deconvolution algorithm. The final early-warning biomarkers associated with heart-exosome genetic-signatures for AMI was identified by integration with single-cell sequencing, weighted gene correction network and machine learning analyses. The correlation between biomarkers and clinical indicators was validated in impatient cohort. A nomogram was generated using early-warning biomarkers for predicting the CAD progression. The molecular subtypes landscape of AMI was detected by consensus clustering. A higher fraction of exosomes derived from spleen and blood cells was revealed in plasma exosomes, while a lower fraction of heart-exosomes was detected. The gene ontology revealed that heart-exosomes genetic-signatures was associated with the heart development, cardiac function and cardiac response to stress. We ultimately identified three genes associated with heart-exosomes defining early-warning biomarkers for AMI. The early-warning biomarkers mediated molecular clusters presented heterogeneous metabolism preference in AMI. Our study introduced three early-warning biomarkers associated with heart-exosome genetic-signatures, which reflected the genetic information of heart-exosomes carrying AMI signals and provided new insights for exosomes research in CAD progression and prevention.


Biomarkers , Exosomes , Myocardial Infarction , Exosomes/genetics , Exosomes/metabolism , Myocardial Infarction/genetics , Myocardial Infarction/diagnosis , Humans , Female , Male , Myocardium/metabolism , Myocardium/pathology , Transcriptome/genetics
3.
Nat Commun ; 15(1): 3481, 2024 Apr 25.
Article En | MEDLINE | ID: mdl-38664417

Viral myocarditis, an inflammatory disease of the myocardium, is a significant cause of sudden death in children and young adults. The current coronavirus disease 19 pandemic emphasizes the need to understand the pathogenesis mechanisms and potential treatment strategies for viral myocarditis. Here, we found that TRIM29 was highly induced by cardiotropic viruses and promoted protein kinase RNA-like endoplasmic reticulum kinase (PERK)-mediated endoplasmic reticulum (ER) stress, apoptosis, and reactive oxygen species (ROS) responses that promote viral replication in cardiomyocytes in vitro. TRIM29 deficiency protected mice from viral myocarditis by promoting cardiac antiviral functions and reducing PERK-mediated inflammation and immunosuppressive monocytic myeloid-derived suppressor cells (mMDSC) in vivo. Mechanistically, TRIM29 interacted with PERK to promote SUMOylation of PERK to maintain its stability, thereby promoting PERK-mediated signaling pathways. Finally, we demonstrated that the PERK inhibitor GSK2656157 mitigated viral myocarditis by disrupting the TRIM29-PERK connection, thereby bolstering cardiac function, enhancing cardiac antiviral responses, and curbing inflammation and immunosuppressive mMDSC in vivo. Our findings offer insight into how cardiotropic viruses exploit TRIM29-regulated PERK signaling pathways to instigate viral myocarditis, suggesting that targeting the TRIM29-PERK axis could mitigate disease severity.


Adenine/analogs & derivatives , Endoplasmic Reticulum Stress , Indoles , Myocarditis , Myocytes, Cardiac , eIF-2 Kinase , Animals , Myocarditis/virology , Myocarditis/metabolism , Myocarditis/pathology , eIF-2 Kinase/metabolism , eIF-2 Kinase/genetics , Male , Mice , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/virology , Myocytes, Cardiac/pathology , Transcription Factors/metabolism , Transcription Factors/genetics , Reactive Oxygen Species/metabolism , Mice, Knockout , Signal Transduction , Humans , Mice, Inbred C57BL , Apoptosis , Virus Replication , Myocardium/pathology , Myocardium/metabolism
4.
Nat Commun ; 15(1): 3528, 2024 Apr 25.
Article En | MEDLINE | ID: mdl-38664444

Cardiac dysfunction is a hallmark of aging in humans and mice. Here we report that a two-week treatment to restore youthful Bridging Integrator 1 (BIN1) levels in the hearts of 24-month-old mice rejuvenates cardiac function and substantially reverses the aging phenotype. Our data indicate that age-associated overexpression of BIN1 occurs alongside dysregulated endosomal recycling and disrupted trafficking of cardiac CaV1.2 and type 2 ryanodine receptors. These deficiencies affect channel function at rest and their upregulation during acute stress. In vivo echocardiography reveals reduced systolic function in old mice. BIN1 knockdown using an adeno-associated virus serotype 9 packaged shRNA-mBIN1 restores the nanoscale distribution and clustering plasticity of ryanodine receptors and recovers Ca2+ transient amplitudes and cardiac systolic function toward youthful levels. Enhanced systolic function correlates with increased phosphorylation of the myofilament protein cardiac myosin binding protein-C. These results reveal BIN1 knockdown as a novel therapeutic strategy to rejuvenate the aging myocardium.


Adaptor Proteins, Signal Transducing , Aging , Myocardium , Nerve Tissue Proteins , Ryanodine Receptor Calcium Release Channel , Tumor Suppressor Proteins , Animals , Adaptor Proteins, Signal Transducing/metabolism , Adaptor Proteins, Signal Transducing/genetics , Male , Aging/metabolism , Mice , Tumor Suppressor Proteins/metabolism , Tumor Suppressor Proteins/genetics , Myocardium/metabolism , Myocardium/pathology , Ryanodine Receptor Calcium Release Channel/metabolism , Ryanodine Receptor Calcium Release Channel/genetics , Gene Knockdown Techniques , Endosomes/metabolism , Calcium Channels, L-Type/metabolism , Calcium Channels, L-Type/genetics , Heart/physiopathology , Mice, Inbred C57BL , Humans , Myocytes, Cardiac/metabolism , Nuclear Proteins/metabolism , Nuclear Proteins/genetics , RNA, Small Interfering/metabolism , RNA, Small Interfering/genetics , Systole
5.
Cardiovasc Diabetol ; 23(1): 129, 2024 Apr 15.
Article En | MEDLINE | ID: mdl-38622592

The long-term high-fat diet (HFD) can cause myocardial lipotoxicity, which is characterized pathologically by myocardial hypertrophy, fibrosis, and remodeling and clinically by cardiac dysfunction and heart failure in patients with obesity and diabetes. Circular RNAs (circRNAs), a novel class of noncoding RNA characterized by a ring formation through covalent bonds, play a critical role in various cardiovascular diseases. However, few studies have been conducted to investigate the role and mechanism of circRNA in myocardial lipotoxicity. Here, we found that circ_005077, formed by exon 2-4 of Crmp1, was significantly upregulated in the myocardium of an HFD-fed rat. Furthermore, we identified circ_005077 as a novel ferroptosis-related regulator that plays a role in palmitic acid (PA) and HFD-induced myocardial lipotoxicity in vitro and in vivo. Mechanically, circ_005077 interacted with Cyclophilin A (CyPA) and inhibited its degradation via the ubiquitination proteasome system (UBS), thus promoting the interaction between CyPA and p47phox to enhance the activity of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase responsible for ROS generation, subsequently inducing ferroptosis. Therefore, our results provide new insights into the mechanisms of myocardial lipotoxicity, potentially leading to the identification of a novel therapeutic target for the treatment of myocardial lipotoxicity in the future.


Cyclophilin A , Diet, High-Fat , Ferroptosis , Animals , Rats , Cyclophilin A/metabolism , Myocardium/metabolism , Obesity/metabolism
6.
Signal Transduct Target Ther ; 9(1): 94, 2024 Apr 22.
Article En | MEDLINE | ID: mdl-38644381

Much effort has been made to uncover the cellular heterogeneities of human hearts by single-nucleus RNA sequencing. However, the cardiac transcriptional regulation networks have not been systematically described because of the limitations in detecting transcription factors. In this study, we optimized a pipeline for isolating nuclei and conducting single-nucleus RNA sequencing targeted to detect a higher number of cell signal genes and an optimal number of transcription factors. With this unbiased protocol, we characterized the cellular composition of healthy human hearts and investigated the transcriptional regulation networks involved in determining the cellular identities and functions of the main cardiac cell subtypes. Particularly in fibroblasts, a novel regulator, PKNOX2, was identified as being associated with physiological fibroblast activation in healthy hearts. To validate the roles of these transcription factors in maintaining homeostasis, we used single-nucleus RNA-sequencing analysis of transplanted failing hearts focusing on fibroblast remodelling. The trajectory analysis suggested that PKNOX2 was abnormally decreased from fibroblast activation to pathological myofibroblast formation. Both gain- and loss-of-function in vitro experiments demonstrated the inhibitory role of PKNOX2 in pathological fibrosis remodelling. Moreover, fibroblast-specific overexpression and knockout of PKNOX2 in a heart failure mouse model induced by transverse aortic constriction surgery significantly improved and aggravated myocardial fibrosis, respectively. In summary, this study established a high-quality pipeline for single-nucleus RNA-sequencing analysis of heart muscle. With this optimized protocol, we described the transcriptional regulation networks of the main cardiac cell subtypes and identified PKNOX2 as a novel regulator in suppressing fibrosis and a potential therapeutic target for future translational studies.


Fibrosis , Homeodomain Proteins , Myocardium , Humans , Mice , Animals , Fibrosis/genetics , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Myocardium/pathology , Myocardium/metabolism , Fibroblasts/metabolism , Fibroblasts/pathology , Myofibroblasts/metabolism , Myofibroblasts/pathology , Mice, Knockout , Heart Failure/genetics , Heart Failure/pathology , Heart Failure/metabolism , Disease Models, Animal , Male
8.
J Cell Mol Med ; 28(8): e18281, 2024 Apr.
Article En | MEDLINE | ID: mdl-38652092

Conditions to which the cardiac graft is exposed during transplantation with donation after circulatory death (DCD) can trigger the recruitment of macrophages that are either unpolarized (M0) or pro-inflammatory (M1) as well as the release of extracellular vesicles (EV). We aimed to characterize the effects of M0 and M1 macrophage-derived EV administration on post-ischaemic functional recovery and glucose metabolism using an isolated rat heart model of DCD. Isolated rat hearts were subjected to 20 min aerobic perfusion, followed by 27 min global, warm ischaemia or continued aerobic perfusion and 60 min reperfusion with or without intravascular administration of EV. Four experimental groups were compared: (1) no ischaemia, no EV; (2) ischaemia, no EV; (3) ischaemia with M0-macrophage-dervied EV; (4) ischaemia with M1-macrophage-derived EV. Post-ischaemic ventricular and metabolic recovery were evaluated. During reperfusion, ventricular function was decreased in untreated ischaemic and M1-EV hearts, but not in M0-EV hearts, compared to non-ischaemic hearts (p < 0.05). In parallel with the reduced functional recovery in M1-EV versus M0-EV ischaemic hearts, rates of glycolysis from exogenous glucose and oxidative metabolism tended to be lower, while rates of glycogenolysis and lactate release tended to be higher. EV from M0- and M1-macrophages differentially affect post-ischaemic cardiac recovery, potentially by altering glucose metabolism in a rat model of DCD. Targeted EV therapy may be a useful approach for modulating cardiac energy metabolism and optimizing graft quality in the setting of DCD.


Extracellular Vesicles , Heart Transplantation , Macrophages , Animals , Extracellular Vesicles/metabolism , Extracellular Vesicles/transplantation , Rats , Macrophages/metabolism , Male , Heart Transplantation/methods , Glucose/metabolism , Myocardium/metabolism , Disease Models, Animal , Recovery of Function , Glycolysis , Heart/physiopathology , Heart/physiology
9.
PLoS One ; 19(4): e0301036, 2024.
Article En | MEDLINE | ID: mdl-38625956

PURPOSE: This study aims to investigate the protective mechanism of dihydromyricetin PLGA nanoparticles (DMY-PLGA NPs) against myocardial ischemia-reperfusion injury (MIRI) in vitro and the improvement of oral bioavailability in vivo. METHODS: DMY-PLGA NPs was prepared and characterized by emulsifying solvent volatilization, and the oxidative stress model of rat H9c2 cardiomyocyte induced by H2O2 was established. After administration, cell survival rate, lactate dehydrogenase (LDH), malondialdehyde (MDA) and superoxide dismutase (SOD) were detected, and the expressions of PGC1α and PPARα were detected by western blot (WB). At the same time, the pharmacokinetics in rats were studied to explore the improvement of bioavailability. RESULTS: DMY-PLGA NPs can significantly increase cell survival rate, decrease LDH and MDA content, increase SOD content and PGC1α、PPARα protein expression. Compared with DMY, the peak time of DMY-PLGA NPs was extended (P<0.1), and the bioavailability was increased by 2.04 times. CONCLUSION: DMY-PLGA NPs has a significant protective effect on H9c2 cardiomyocytes, which promotes the absorption of DMY and effectively improves bioavailability.


Flavonols , Hydrogen Peroxide , PPAR alpha , Rats , Animals , Hydrogen Peroxide/metabolism , PPAR alpha/metabolism , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism , Oxidative Stress , Myocardium/metabolism , Myocytes, Cardiac/metabolism , Superoxide Dismutase/metabolism , Apoptosis
10.
Mol Biol Rep ; 51(1): 532, 2024 Apr 18.
Article En | MEDLINE | ID: mdl-38637360

BACKGROUND: Doxorubicin is an effective antineoplastic agent but has limited clinical application because of its cumulative toxicities, including cardiotoxicity. Cardiotoxicity causes lipid peroxidation, genetic impairment, oxidative stress, inhibition of autophagy, and disruption of calcium homeostasis. Doxorubicin-induced cardiotoxicity is frequently tried to be mitigated by phytochemicals, which are derived from plants and possess antioxidant, anti-inflammatory, and anti-apoptotic properties. Arbutin, a natural antioxidant found in the leaves of the bearberry plant, has numerous pharmacological benefits, including antioxidant, anti-bacterial, anti-hyperglycemic, anti-inflammatory, and anti-tumor activity. METHODS AND RESULTS: The study involved male Wistar rats divided into three groups: a control group, a group treated with doxorubicin (20 mg/kg) to induce cardiac toxicity, a group treated with arbutin (100 mg/kg) daily for two weeks before doxorubicin administration. After treatment, plasma and heart tissue samples were collected for analysis. The samples were evaluated for oxidative stress parameters, including superoxide dismutase, malondialdehyde, and catalase, as well as for cardiac biomarkers, including CK, CK-MB, and LDH. The heart tissues were also analyzed using molecular (TNF-α, IL-1ß and Caspase 3), histopathological and immunohistochemical methods (8-OHDG, 4 Hydroxynonenal, and dityrosine). The results showed that arbutin treatment was protective against doxorubicin-induced oxidative damage by increasing SOD and CAT activity and decreasing MDA level. Arbutin treatment was similarly able to reverse the inflammatory response caused by doxorubicin by reducing TNF-α and IL-1ß levels and also reverse the apoptosis by decreasing caspase-3 levels. It was able to prevent doxorubicin-induced cardiac damage by reducing cardiac biomarkers CK, CK-MB and LDH levels. In addition to all these results, histopathological analyzes also show that arbutin may be beneficial against the damage caused by doxorubicin on heart tissue. CONCLUSION: The study suggests that arbutin has the potential to be used to mitigate doxorubicin-induced cardiotoxicity in cancer patients.


Antioxidants , Cardiotoxicity , Humans , Rats , Animals , Antioxidants/metabolism , Cardiotoxicity/drug therapy , Cardiotoxicity/prevention & control , Cardiotoxicity/etiology , Arbutin/pharmacology , Arbutin/metabolism , Arbutin/therapeutic use , Myocardium/metabolism , Tumor Necrosis Factor-alpha/metabolism , Rats, Wistar , Doxorubicin/adverse effects , Oxidative Stress , Anti-Inflammatory Agents/pharmacology , Apoptosis , Biomarkers/metabolism
12.
Stem Cell Res Ther ; 15(1): 120, 2024 Apr 24.
Article En | MEDLINE | ID: mdl-38659015

BACKGROUND: Diabetic cardiomyopathy (DCM) is a serious health-threatening complication of diabetes mellitus characterized by myocardial fibrosis and abnormal cardiac function. Human umbilical cord mesenchymal stromal cells (hUC-MSCs) are a potential therapeutic tool for DCM and myocardial fibrosis via mechanisms such as the regulation of microRNA (miRNA) expression and inflammation. It remains unclear, however, whether hUC-MSC therapy has beneficial effects on cardiac function following different durations of diabetes and which mechanistic aspects of DCM are modulated by hUC-MSC administration at different stages of its development. This study aimed to investigate the therapeutic effects of intravenous administration of hUC-MSCs on DCM following different durations of hyperglycemia in an experimental male model of diabetes and to determine the effects on expression of candidate miRNAs, target mRNA and inflammatory mediators. METHODS: A male mouse model of diabetes was induced by multiple low-dose streptozotocin injections. The effects on severity of DCM of intravenous injections of hUC-MSCs and saline two weeks previously were compared at 10 and 18 weeks after diabetes induction. At both time-points, biochemical assays, echocardiography, histopathology, polymerase chain reaction (PCR), immunohistochemistry and enzyme-linked immunosorbent assays (ELISA) were used to analyze blood glucose, body weight, cardiac structure and function, degree of myocardial fibrosis and expression of fibrosis-related mRNA, miRNA and inflammatory mediators. RESULTS: Saline-treated diabetic male mice had impaired cardiac function and increased cardiac fibrosis after 10 and 18 weeks of diabetes. At both time-points, cardiac dysfunction and fibrosis were improved in hUC-MSC-treated mice. Pro-fibrotic indicators (α-SMA, collagen I, collagen III, Smad3, Smad4) were reduced and anti-fibrotic mediators (FGF-1, miRNA-133a) were increased in hearts of diabetic animals receiving hUC-MSCs compared to saline. Increased blood levels of pro-inflammatory cytokines (IL-6, TNF, IL-1ß) and increased cardiac expression of IL-6 were also observed in saline-treated mice and were reduced by hUC-MSCs at both time-points, but to a lesser degree at 18 weeks. CONCLUSION: Intravenous injection of hUC-MSCs ameliorated key functional and structural features of DCM in male mice with diabetes of shorter and longer duration. Mechanistically, these effects were associated with restoration of intra-myocardial expression of miRNA-133a and its target mRNA COL1AI as well as suppression of systemic and localized inflammatory mediators.


Diabetes Mellitus, Experimental , Diabetic Cardiomyopathies , Fibrosis , Mesenchymal Stem Cell Transplantation , Mesenchymal Stem Cells , MicroRNAs , Myocardium , Umbilical Cord , Animals , MicroRNAs/genetics , MicroRNAs/metabolism , Diabetic Cardiomyopathies/therapy , Diabetic Cardiomyopathies/metabolism , Diabetic Cardiomyopathies/pathology , Diabetic Cardiomyopathies/genetics , Humans , Male , Fibrosis/therapy , Mice , Mesenchymal Stem Cells/metabolism , Umbilical Cord/cytology , Umbilical Cord/metabolism , Mesenchymal Stem Cell Transplantation/methods , Diabetes Mellitus, Experimental/therapy , Diabetes Mellitus, Experimental/metabolism , Myocardium/metabolism , Myocardium/pathology , Mice, Inbred C57BL
13.
Cell Mol Biol (Noisy-le-grand) ; 70(3): 197-203, 2024 Mar 31.
Article En | MEDLINE | ID: mdl-38650132

Myocardial fibrosis is a common pathological manifestation that occurs in various cardiac diseases. The present investigation aims to reveal how DNMT1/lncRNA-ANRIL/NLRP3 influences fibrosis and cardiac fibroblast pyroptosis. Here, we used ISO to induce myocardial fibrosis in mice, and LPS and ATP to induce myocardial fibroblast pyroptosis. The results showed that DNMT1, Caspase-1, and NLRP3 expression were significantly increased in fibrotic murine myocardium and pyroptotic cardiac fibroblasts, whereas LncRNA-ANRIL expression was decreased. DNMT1 overexpression decreased the level of LncRNA-ANRIL while increasing the levels of NLRP3 and Caspase-1. Contrarily, silencing DNMT1 increased the LncRNA-ANRIL and decreased the levels of NLRP3 and Caspase-1. Silencing LncRNA-ANRIL increased the levels of NLRP3 and Caspase-1. The present findings suggest that DNMT1 can methylate LncRNA-ANRIL during the development of myocardial fibrosis and CFs cell scorching, resulting in low LncRNA-ANRIL expression, thereby influencing myocardial fibrosis and cardiac fibroblast pyroptosis.


Caspase 1 , DNA (Cytosine-5-)-Methyltransferase 1 , DNA Methylation , Fibroblasts , Fibrosis , Myocardium , NLR Family, Pyrin Domain-Containing 3 Protein , Pyroptosis , RNA, Long Noncoding , Signal Transduction , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Pyroptosis/genetics , Pyroptosis/drug effects , Animals , DNA (Cytosine-5-)-Methyltransferase 1/metabolism , DNA (Cytosine-5-)-Methyltransferase 1/genetics , Caspase 1/metabolism , Caspase 1/genetics , Fibroblasts/metabolism , Myocardium/pathology , Myocardium/metabolism , Mice , DNA Methylation/genetics , Male , Mice, Inbred C57BL
15.
Int J Mol Med ; 53(6)2024 Jun.
Article En | MEDLINE | ID: mdl-38666537

Fibroblast growth factor (FGF)21 is a peptide hormone that improves mitochondrial function and energy metabolism, and the deficiency of its co­receptor ß­klotho (KLB) causes decreased FGF21 sensitivity. The present study examined whether the cardiac delivery of plasmids containing the KLB gene via ultrasound­targeted microbubble destruction (UTMD) enhances the efficacy of FGF21 against heart failure post­acute myocardial infarction (AMI). For this purpose, the levels of FGF21 in patients and rats with heart dysfunction post­infarction were determined using ELISA. Sprague­Dawley rats received the 3X UTMD­mediated delivery of KLB@cationic microbubbles (KLB@CMBs) 1 week following the induction of AMI. Echocardiography, histopathology and biochemical analysis were performed at 4 weeks following the induction of AMI. The results revealed that patients with heart failure post­infarction had higher serum FGF21 levels than the healthy controls. However, the downstream signal, KLB, but not α­klotho, was reduced in the heart tissues of rats with AMI. As was expected, treatment with FGF21 did not substantially attenuate heart remodeling post­infarction. It was found that decreased receptors KLB in the heart may result in the insensitivity to FGF21 treatment. In vivo, the UTMD technology­mediated delivery of KLB@CMBs to the heart significantly enhanced the effects of FGF21 administration on cardiac remodeling and mitochondrial dysfunction in the rats following infarction. The delivery of KLB to the heart by UTMD and the administration of FGF21 attenuated mitochondrial impairment and oxidative stress by activating nuclear factor erythroid 2­related factor 2 signals. On the whole, the present study demonstrates that the cardiac delivery of KLB significantly optimizes the cardioprotective effects of FGF21 therapy on adverse heart remodeling. UTMD appears a promising interdisciplinary approach with which to improve heart failure post­myocardial infarction.


Fibroblast Growth Factors , Klotho Proteins , Microbubbles , Myocardial Infarction , Rats, Sprague-Dawley , Ventricular Remodeling , Fibroblast Growth Factors/administration & dosage , Fibroblast Growth Factors/metabolism , Fibroblast Growth Factors/pharmacology , Animals , Myocardial Infarction/metabolism , Myocardial Infarction/therapy , Humans , Male , Rats , Ventricular Remodeling/drug effects , Female , Ultrasonic Waves , Myocardium/metabolism , Myocardium/pathology , Heart Failure/metabolism , Heart Failure/therapy
16.
Biochemistry (Mosc) ; 89(1): 116-129, 2024 Jan.
Article En | MEDLINE | ID: mdl-38467549

Cardiac myosin binding protein C (cMyBP-C) is one of the essential control components of the myosin cross-bridge cycle. The C-terminal part of cMyBP-C is located on the surface of the thick filament, and its N-terminal part interacts with actin, myosin, and tropomyosin, affecting both kinetics of the ATP hydrolysis cycle and lifetime of the cross-bridge, as well as calcium regulation of the actin-myosin interaction, thereby modulating contractile function of myocardium. The role of cMyBP-C in atrial contraction has not been practically studied. We examined effect of the N-terminal C0-C1-m-C2 (C0-C2) fragment of cMyBP-C on actin-myosin interaction using ventricular and atrial myosin in an in vitro motility assay. The C0-C2 fragment of cMyBP-C significantly reduced the maximum sliding velocity of thin filaments on both myosin isoforms and increased the calcium sensitivity of the actin-myosin interaction. The C0-C2 fragment had different effects on the kinetics of ATP and ADP exchange, increasing the affinity of ventricular myosin for ADP and decreasing the affinity of atrial myosin. The effect of the C0-C2 fragment on the activation of the thin filament depended on the myosin isoforms. Atrial myosin activates the thin filament less than ventricular myosin, and the C0-C2 fragment makes these differences in the myosin isoforms more pronounced.


Actins , Protein C , Actins/metabolism , Protein C/metabolism , Carrier Proteins/metabolism , Calcium/metabolism , Atrial Myosins , Ventricular Myosins/metabolism , Myosins/metabolism , Myocardium/metabolism , Adenosine Triphosphate/metabolism , Protein Isoforms/metabolism , Protein Binding
17.
Int J Mol Sci ; 25(5)2024 Mar 01.
Article En | MEDLINE | ID: mdl-38474134

The slmap gene is alternatively spliced to generate many isoforms that are abundant in developing myocardium. The largest protein isoform SLMAP3 is ubiquitously expressed and has been linked to cardiomyopathy, Brugada syndrome and Hippo signaling. To examine any role in cardiogenesis, mice homozygous for floxed slmap allele were crossed with Nkx2.5-cre mice to nullify its expression in cardiac progenitors. Targeted deletion of the slmap gene resulted in the specific knockout (KO) of the SLMAP3 (~91 KDa) isoform without any changes in the expression of the SLMAP2 (~43 kDa) or the SLMAP1 (~35 kDa) isoforms which continued to accumulate to similar levels as seen in Wt embryonic hearts. The loss of SLMAP3 from cardiac progenitors resulted in decreased size of the developing embryonic hearts evident at E9.5 to E16.5 with four small chambers and significantly thinner left ventricles. The proliferative capacity assessed with the phosphorylation of histone 3 or with Ki67 in E12.5 hearts was not significantly altered due to SLMAP3 deficiency. The size of embryonic cardiomyocytes, marked with anti-Troponin C, revealed significantly smaller cells, but their hypertrophic response (AKT1 and MTOR1) was not significantly affected by the specific loss of SLMAP3 protein. Further, no changes in phosphorylation of MST1/2 or YAP were detected in SLMAP3-KO embryonic myocardium, ruling out any impact on Hippo signaling. Rat embryonic cardiomyocytes express the three SLMAP isoforms and their knockdown (KD) with sh-RNA, resulted in decreased proliferation and enhanced senescence but without any impact on Hippo signaling. Collectively, these data show that SLMAP is critical for normal cardiac development with potential for the various isoforms to serve compensatory roles. Our data imply novel mechanisms for SLMAP action in cardiac growth independent of Hippo signaling.


Hippo Signaling Pathway , Myocardium , Mice , Rats , Animals , Myocardium/metabolism , Myocytes, Cardiac/metabolism , Membrane Proteins/metabolism , Protein Isoforms/metabolism
18.
Int Immunopharmacol ; 131: 111883, 2024 Apr 20.
Article En | MEDLINE | ID: mdl-38503016

Infarct healing requires a dynamic and orchestrated inflammatory reaction following myocardial infarction (MI). While an uncontrolled excessive inflammatory response exaggerates ischemic injury post-MI, M2-like reparative macrophages may facilitate inflammation regression and promote myocardial healing. However, how protein post-translational modification regulates post-MI cardiac repair and dynamic myeloid activation remains unknown. Here we show that M2-like reparative, but not M1-like inflammatory activation, is enhanced by pharmacologically-induced hyper-O-GlcNAcylation. Mechanistically, myeloid knockdown of O-GlcNAc hydrolase O-GlcNAcase (Oga), which also results in hyper-O-GlcNAcylation, positively regulates M2-like activation in a STAT6-dependent fashion, which is controlled by O-GlcNAcylation of STAT6. Of note, both systemic and local supplementation of thiamet-G (TMG), an Oga inhibitor, effectively facilitates cardiac recovery in mice by elevating the accumulation of M2-like macrophages in infarcted hearts. Our study provides a novel clue for monocyte/macrophage modulating therapies aimed at reducing post-MI hyperinflammation in ischemic myocardium.


Hydrogels , Myocardial Infarction , Mice , Animals , Hydrogels/metabolism , Myocardium/metabolism , Heart , Myocardial Infarction/drug therapy , Myocardial Infarction/metabolism , Protein Processing, Post-Translational , Acetylglucosaminidase/metabolism
19.
Expert Opin Investig Drugs ; 33(4): 389-404, 2024 Apr.
Article En | MEDLINE | ID: mdl-38426439

INTRODUCTION: Myocardial fibrosis (MF) is induced by factors activating pro-fibrotic pathways such as acute and prolonged inflammation, myocardial ischemic events, hypertension, aging process, and genetically-linked cardiomyopathies. Dynamics and characteristics of myocardial fibrosis development are very different. The broad range of myocardial fibrosis presentations suggests the presence of multiple potential targets. AREA COVERED: Heart failure treatment involves medications primarily aimed at counteracting neurohormonal activation. While these drugs have demonstrated efficacy against MF, not all specifically target inflammation or fibrosis progression with some exceptions such as RAAS inhibitors. Consequently, new therapies are being developed to address this issue. This article is aimed to describe anti-fibrotic drugs currently employed in clinical practice and emerging agents that target specific pathways, supported by evidence from both preclinical and clinical studies. EXPERT OPINION: Despite various preclinical findings suggesting the potential utility of new drugs and molecules for treating cardiac fibrosis in animal models, there is a notable scarcity of clinical trials investigating these effects. However, the pathology of damage and repair in the heart muscle involves a complex network of interconnected inflammatory pathways and various types of immune cells. Our comprehension of the positive and negative roles played by specific immune cells and cytokines is an emerging area of research.


Cardiomyopathies , Heart Failure , Animals , Humans , Cardiomyopathies/metabolism , Myocardium/metabolism , Myocardium/pathology , Heart Failure/drug therapy , Fibrosis , Inflammation/pathology
20.
Biomolecules ; 14(3)2024 Mar 06.
Article En | MEDLINE | ID: mdl-38540729

Heart failure (HF) represents a significant global health challenge, characterized by high morbidity and mortality rates, and imposes considerable burdens on healthcare systems and patient quality of life. Traditional management strategies, primarily relying on clinical assessments and standard biomarkers like natriuretic peptides, face limitations due to the heterogeneity of HF. This review aims to delve into the evolving landscape of non-natriuretic biomarkers and the transformative potential of omics technologies, underscoring their roles in advancing HF treatment towards precision medicine. By offering novel insights into the biological underpinnings of HF, including inflammation, myocardial stress, fibrosis, and metabolic disturbances, these advancements facilitate more accurate patient phenotyping and individualized treatment strategies. The integration of non-natriuretic biomarkers and omics technologies heralds a pivotal shift in HF management, enabling a move towards tailored therapeutic interventions. This approach promises to enhance clinical outcomes by improving diagnostic accuracy, risk stratification, and monitoring therapeutic responses. However, challenges such as the variability in biomarker levels, cost-effectiveness, and the standardization of biomarker testing across different healthcare settings pose hurdles to their widespread adoption. Despite these challenges, the promise of precision medicine in HF, driven by these innovative biomarkers and technologies, offers a new horizon for improving patient care and outcomes. This review advocates for the further integration of these advancements into clinical practice, highlighting the need for ongoing research to fully realize their potential in transforming the landscape of heart failure management.


Heart Failure , Quality of Life , Humans , Heart Failure/diagnosis , Natriuretic Peptides/therapeutic use , Biomarkers , Myocardium/metabolism
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