This study explores the role and underlying molecular mechanisms of fucoidan sulfate(FPS) in regulating heme oxygenase-1(Hmox1)-mediated ferroptosis to ameliorate myocardial injury in diabetic cardiomyopathy(DCM) through in vivo and in vitro experiments and network pharmacology analysis. In vivo, a DCM rat model was established using a combination of "high-fat diet feeding + two low-dose streptozotocin(STZ) intraperitoneal injections". The rats were randomly divided into four groups: normal, model, FPS, and dapagliflozin(Dapa) groups. In vitro, a cellular model was created by inducing rat cardiomyocytes(H9c2 cells) with high glucose(HG), using zinc protoporphyrin(ZnPP), an Hmox1 inhibitor, as the positive control. An automatic biochemical analyzer was used to measure blood glucose(BG), serum aspartate aminotransferase(AST), serum lactate dehydrogenase(LDH), and serum creatine kinase-MB(CK-MB) levels. Echocardiography was used to assess rat cardiac function, including ejection fraction(EF) and fractional shortening(FS). Pathological staining was performed to observe myocardial morphology and fibrotic characteristics. DCFH-DA fluorescence probe was used to detect reactive oxygen species(ROS) levels in myocardial tissue. Specific assay kits were used to measure serum brain natriuretic peptide(BNP), myocardial Fe~(2+), and malondialdehyde(MDA) levels. Western blot(WB) was used to detect the expression levels of myosin heavy chain 7B(MYH7B), natriuretic peptide A(NPPA), collagens type Ⅰ(Col-Ⅰ), α-smooth muscle actin(α-SMA), ferritin heavy chain 1(FTH1), solute carrier family 7 member 11(SLC7A11), glutathione peroxidase 4(GPX4), 4-hydroxy-2-nonenal(4-HNE), and Hmox1. Immunohistochemistry(IHC) was used to examine Hmox1 protein expression patterns. FerroOrange and Highly Sensitive DCFH-DA fluorescence probes were used to detect intracellular Fe~(2+) and ROS levels. Transmission electron microscopy was used to observe changes in mitochondrial morphology. In network pharmacology, FPS targets were identified through the PubChem database and PharmMapper platform. DCM-related targets were integrated from OMIM, GeneCards, and DisGeNET databases, while ferroptosis-related targets were obtained from the FerrDb database. A protein-protein interaction(PPI) network was constructed for the intersection of these targets using STRING 11.0, and core targets were screened with Cytoscape 3.9.0. Molecular docking analysis was conducted using AutoDock and PyMOL 2.5. In vivo results showed that FPS significantly reduced AST, LDH, CK-MB, and BNP levels in DCM model rats, improved cardiac function, decreased the expression of myocardial injury proteins(MYH7B, NPPA, Col-Ⅰ, and α-SMA), alleviated myocardial hypertrophy and fibrosis, and reduced Fe~(2+), ROS, and MDA levels in myocardial tissue. Furthermore, FPS regulated the expression of ferroptosis-related markers(Hmox1, FTH1, SLC7A11, GPX4, and 4-HNE) to varying degrees. Network pharmacology results revealed 313 potential targets for FPS, 1 125 targets for DCM, and 14 common targets among FPS, DCM, and FerrDb. Hmox1 was identified as a key target, with FPS showing high docking activity with Hmox1. In vitro results demonstrated that FPS restored the expression levels of ferroptosis-related proteins, reduced intracellular Fe~(2+) and ROS levels, and alleviated mitochondrial structural damage in cardiomyocytes. In conclusion, FPS improves myocardial injury in DCM, with its underlying mechanism potentially involving the regulation of Hmox1 to inhibit ferroptosis. This study provides pharmacological evidence supporting the therapeutic potential of FPS for DCM-induced myocardial injury.
Animals ; Ferroptosis/drug effects* ; Rats ; Diabetic Cardiomyopathies/physiopathology* ; Male ; Rats, Sprague-Dawley ; Polysaccharides/pharmacology* ; Heme Oxygenase-1/genetics* ; Myocytes, Cardiac/metabolism* ; Myocardium/pathology* ; Humans ; Cell Line ; Heme Oxygenase (Decyclizing)

Diabetic cardiomyopathy (DCM) is a medical condition characterized by cardiac remodeling and dysfunction in individuals with diabetes mellitus. Sarcoplasmic reticulum (SR) and mitochondrial Ca²⁺ overload in cardiomyocytes have been recognized as biological hallmarks in DCM; however, the specific factors underlying these abnormalities remain largely unknown. In this study, we aimed to investigate the role of a cardiac-specific long noncoding RNA, D830005E20Rik (Trdn-as), in DCM. Our results revealed the remarkably upregulation of Trdn-as in the hearts of the DCM mice and cardiomyocytes treated with high glucose (HG). Knocking down Trdn-as in cardiac tissues significantly improved cardiac dysfunction and remodeling in the DCM mice. Conversely, Trdn-as overexpression resulted in cardiac damage resembling that observed in the DCM mice. At the cellular level, Trdn-as induced Ca²⁺ overload in the SR and mitochondria, leading to mitochondrial dysfunction. RNA-seq and bioinformatics analyses identified calsequestrin 2 (Casq2), a primary calcium-binding protein in the junctional SR, as a potential target of Trdn-as. Further investigations revealed that Trdn-as facilitated the recruitment of METTL14 to the Casq2 mRNA, thereby enhancing the m⁶A modification of Casq2. This modification increased the stability of Casq2 mRNA and subsequently led to increased protein expression. When Casq2 was knocked down, the promoting effects of Trdn-as on Ca²⁺ overload and mitochondrial damage were mitigated. These findings provide valuable insights into the pathogenesis of DCM and suggest Trdn-as as a potential therapeutic target for this condition.
Animals ; Diabetic Cardiomyopathies/pathology* ; RNA, Long Noncoding/genetics* ; Myocytes, Cardiac/metabolism* ; Mice ; Calsequestrin/genetics* ; Calcium/metabolism* ; Male ; Sarcoplasmic Reticulum/metabolism* ; Methyltransferases/metabolism* ; Mice, Inbred C57BL ; Mitochondria, Heart/metabolism* ; Disease Models, Animal ; Mitochondria/metabolism*

Sepsis is a life-threatening organ dysfunction caused by the body's dysregulated response to infection. Reversible myocardial dysfunction caused by sepsis is known as septic cardiomyopathy. A thorough understanding of the pathogenesis of septic cardiomyopathy is crucial for early intervention to prevent its progression and improve the success rate of sepsis treatment. At present, the research on the pathogenesis of septic cardiomyopathy mainly focuses on two aspects: the systemic neuroimmune mechanism and the local changes of cardiomyocytes. The former mainly includes the autonomic nervous dysfunction mainly caused by sympathetic overactivation and the inflammatory storm induced by immune response disorder. The latter covers the dysregulation of calcium homeostasis, mitochondrial dysfunction and energy metabolism disorder of cardiomyocytes. Immune dysfunction is one of the key factors that cause the poor prognosis of patients with septic cardiomyopathy. Macrophages are sentinel cells of the body's innate immunity. Cardiac macrophages have been confirmed to be one of the most heterogeneous immune cells in the heart. According to their origin and differentiation, they can be divided into bone marrow-derived tissue infiltrating macrophages and cardiac resident macrophages, which have roles of polarization, phagocytosis, regulation of inflammatory response, and participate in innate and adaptive immunity. In the occurrence and development of septic cardiomyopathy, cardiac macrophages recruited from the blood participate in balancing the inflammation and repair of myocardial tissue through the conversion of pro-inflammatory phenotype and anti-inflammatory phenotype. Cardiac resident macrophages mediate immune phagocytosis to maintain the local homeostasis of cardiomyocytes, and the glycometabolic reprogramming of macrophages regulates the release of inflammatory factors, while macrophage metabolic reprogramming regulates the release of inflammatory factors. A deeper understanding of the biological behavior of macrophages, and regulating the polarization, metabolism and phagocytosis of cardiac macrophages, could serve as new target for the prevention and treatment of septic cardiomyopathy. Therefore, this article reviews the key pathogenesis of septic cardiomyopathy and the role of macrophages of different origins and differentiation, revealing the possibility of developing new strategies for the prevention and treatment of septic cardiomyopathy.
Humans ; Cardiomyopathies/pathology* ; Macrophages/immunology* ; Sepsis/complications* ; Myocytes, Cardiac

This study aimed to investigate the ameliorative effect of Xinyang Tablets on myocardial fibrosis in uremic cardiomyopathy(UCM) using single-cell sequencing technology. UCM mouse models were established by 5/6 nephrectomy(NPM) and randomly divided into the model group, Xinyang Tablets group, and sham-operated(sham) group as the control. The Xinyang Tablets group received postoperative interventions of Xinyang Tablets(0.34 g·kg~(-1)). After eight weeks, the hearts of the mice in each group were disassociated and subjected to 10×Genomics single-cell sequencing. The data were subjected to t-SNE dimensionality reduction, K-means clustering, and CellMarker annotation prior to analyzing differential expression and cell differentiation trajectories using the Seurat and Monocle3 tools. Additionally, the CellChat tool was used to parse intercellular signaling communication. The results showed that a total of nine types of cells including fibroblasts, endothelial cells, and immune cells were identified in this study. The single-cell expression results of fibroblasts and Gene Ontology(GO) enrichment analysis showed that Xinyang Tablets regulated myocardial fibrosis factors and related signals. Mimetic timing analysis identified three major differentiation trajectories of mouse cardiac fibroblasts and identified the expression of secreted phosphoprotein 1(Spp1) as consistent with the fibroblast differentiation trajectory. Cellular interaction network analysis showed that the communication signals between mouse cardiac fibroblasts and other cells were weakened in the Xinyang Tablets group compared with the model group. The results of ligand-receptor interaction analysis showed that the interaction between myeloid cell-derived osteopontin(OPN) and cardiac fibroblasts and between myeloid cell Spp1 ligand and cardiac fibroblast receptor of mice in the Xinyang Tablets group was weakened compared with the model group. In conclusion, Xinyang Tablets may improve myocardial fibrosis in UCM by inhibiting both endogenous and exogenous OPN at the single-cell level.
Animals ; Drugs, Chinese Herbal/administration & dosage* ; Mice ; Cardiomyopathies/pathology* ; Single-Cell Analysis ; Male ; Fibrosis/drug therapy* ; Myocardium/metabolism* ; Uremia/metabolism* ; Tablets ; Mice, Inbred C57BL ; Humans

Objective: To investigate the histological features and clinical manifestations in different types of cardiac amyloidosis to improve diagnostic accuracy. Methods: The histopathological features and clinical manifestations of 48 patients diagnosed with cardiac amyloidosis by Congo red stain and electron microscopy through endomyocardial biopsy were collected in West China Hospital of Sichuan University from January 2018 to December 2021. Immunohistochemical stains for immunoglobulin light chains (κ and λ) and transthyretin protein were carried out, and a review of literature was made. Results: The patients age ranged from 42 to 79 years (mean 56 years) and the male to female ratio was 1.1 to 1.0. The positive rate of endomyocardial biopsy was 97.9% (47/48), which was significantly higher than that of the abdominal wall fat (7/17). Congo red staining and electron microscopy were positive in 97.9% (47/48) and 93.5% (43/46), respectively. Immunohistochemical stains showed 32 cases (68.1%) were light chain type (AL-CA), including 31 cases of AL-λ type and 1 case of AL-κ type; 9 cases (19.1%) were transthyretin protein type (ATTR-CA); and 6 cases (12.8%) were not classified. There was no significant difference in the deposition pattern of amyloid between different types (P>0.05). Clinical data showed that ATTR-CA patients had less involvement of 2 or more organs and lower N-terminal pro-B-type natriuretic peptide (NT-proBNP) than the other type patients (P<0.05). The left ventricular stroke volume and right ventricular ejection fraction of ATTR-CA patients were better than the other patients (P<0.05). Follow-up data of 45 patients was obtained, and the overall mean survival time was 15.6±2.0 months. Univariate survival analysis showed that ATTR-CA patients had a better prognosis, while cardiac amyloidosis patients with higher cardiac function grade, NT-proBNP >6 000 ng/L, and troponin T >70 ng/L had a worse prognosis (P<0.05). Multivariate survival analysis showed that NT-proBNP and cardiac function grade were independent prognostic factors for cardiac amyloidosis patients. Conclusions: AL-λ is the most common type of cardiac amyloidosis in this group. Congo red staining combined with electron microscopy can significantly improve the diagnosis of cardiac amyloidosis. The clinical manifestations and prognosis of each type are different and can be classified based on immunostaining profile. However, there are still a few cases that cannot be typed; hence mass spectrometry is recommended if feasible.
Humans ; Male ; Female ; Adult ; Middle Aged ; Aged ; Prealbumin/metabolism* ; Stroke Volume ; Cardiomyopathies/pathology* ; Congo Red ; Ventricular Function, Right ; Amyloidosis/pathology* ; Prognosis

Histone methylation is one of the key post-translational modifications that plays a critical role in various heart diseases, including diabetic cardiomyopathy. A great deal of evidence has shown that histone methylation is closely related to hyperglycemia, insulin resistance, lipid and advanced glycation end products deposition, inflammatory and oxidative stress, endoplasmic reticulum stress and cell apoptosis, and these pathological factors play an important role in the pathogenesis of diabetic cardiomyopathy. In order to provide a novel theoretical basis and potential targets for the treatment of diabetic cardiomyopathy from the perspective of epigenetics, this review discussed and elucidated the association between histone methylation and the pathogenesis of diabetic cardiomyopathy in details.
Diabetes Mellitus ; Diabetic Cardiomyopathies/pathology* ; Histones ; Humans ; Methylation ; Oxidative Stress ; Protein Processing, Post-Translational

Trypanosoma cruzi infection results in debilitating cardiomyopathy, which is a major cause of mortality and morbidity in the endemic regions of Chagas disease (CD). The pathogenesis of Chagasic cardiomyopathy (CCM) has been intensely studied as a chronic inflammatory disease until recent observations reporting the role of cardio-metabolic dysfunctions. In particular, we demonstrated accumulation of lipid droplets and impaired cardiac lipid metabolism in the hearts of cardiomyopathic mice and patients, and their association with impaired mitochondrial functions and endoplasmic reticulum (ER) stress in CD mice. In the present study, we examined whether treating infected mice with an ER stress inhibitor can modify the pathogenesis of cardiomyopathy during chronic stages of infection. T. cruzi infected mice were treated with an ER stress inhibitor 2-Aminopurine (2AP) during the indeterminate stage and evaluated for cardiac pathophysiology during the subsequent chronic stage. Our study demonstrates that inhibition of ER stress improves cardiac pathology caused by T. cruzi infection by reducing ER stress and downstream signaling of phosphorylated eukaryotic initiation factor (P-elF2α) in the hearts of chronically infected mice. Importantly, cardiac ultrasound imaging showed amelioration of ventricular enlargement, suggesting that inhibition of ER stress may be a valuable strategy to combat the progression of cardiomyopathy in Chagas patients.
2-Aminopurine ; Animals ; Cardiomyopathies ; Chagas Disease ; Endoplasmic Reticulum ; Endoplasmic Reticulum Stress ; Heart ; Humans ; Lipid Droplets ; Lipid Metabolism ; Mice ; Mortality ; Pathology ; Peptide Initiation Factors ; Trypanosoma cruzi ; Ultrasonography

BACKGROUND: Desminopathy, a hereditary myofibrillar myopathy, mainly results from the desmin gene (DES) mutations. Desminopathy involves various phenotypes, mainly including different cardiomyopathies, skeletal myopathy, and arrhythmia. Combined with genotype, it helps us precisely diagnose and treat for desminopathy. METHODS: Sanger sequencing was used to characterize DES variation, and then a minigene assay was used to verify the effect of splice-site mutation on pre-mRNA splicing. Phenotypes were analyzed based on clinical characteristics associated with desminopathy. RESULTS: A splicing mutation (c.735+1G>T) in DES was detected in the proband. A minigene assay revealed skipping of the whole exon 3 and transcription of abnormal pre-mRNA lacking 32 codons. Another affected family member who carried the identical mutation, was identified with a novel phenotype of desminopathy, non-compaction of ventricular myocardium. There were 2 different phenotypes varied in cardiomyopathy and skeletal myopathy among the 2 patients, but no significant correlation between genotype and phenotype was identified. CONCLUSIONS We reported a novel phenotype with a splicing mutation in DES, enlarging the spectrum of phenotype in desminopathy. Molecular studies of desminopathy should promote our understanding of its pathogenesis and provide a precise molecular diagnosis of this disorder, facilitating clinical prevention and treatment at an early stage.
Animals ; Asian Continental Ancestry Group ; Cardiomyopathies ; genetics ; pathology ; Desmin ; genetics ; Electrocardiography ; Female ; Genotype ; Humans ; Male ; Middle Aged ; Muscular Dystrophies ; genetics ; pathology ; Mutation ; genetics ; Pedigree ; Phenotype

OBJECTIVE: To investigate the effect of tea polyphenols on cardiac function in rats with diabetic cardiomyopathy, and the mechanism by which tea polyphenols regulate autophagy in diabetic cardiomyopathy. METHODS: Sixty Sprague-Dawley (SD) rats were randomly divided into six groups: a normal control group (NC), an obesity group (OB), a diabetic cardiomyopathy group (DCM), a tea polyphenol group (TP), an obesity tea polyphenol treatment group (OB-TP), and a diabetic cardiomyopathy tea polyphenol treatment group (DCM-TP). After successful modeling, serum glucose, cholesterol, and triglyceride levels were determined; cardiac structure and function were inspected by ultrasonic cardiography; myocardial pathology was examined by staining with hematoxylin-eosin; transmission electron microscopy was used to observe the morphology and quantity of autophagosomes; and expression levels of autophagy-related proteins LC3-II, SQSTM1/p62, and Beclin-1 were determined by Western blotting. RESULTS: Compared to the NC group, the OB group had normal blood glucose and a high level of blood lipids; both blood glucose and lipids were increased in the DCM group; ultrasonic cardiograms showed that the fraction shortening was reduced in the DCM group. However, these were improved significantly in the DCM-TP group. Hematoxylin-eosin staining showed disordered cardiomyocytes and hypertrophy in the DCM group; however, no differences were found among the remaining groups. Transmission electron microscopy revealed that the numbers of autophagosomes in the DCM and OB-TP groups were obviously increased compared to the NC and OB groups; the number of autophagosomes in the DCM-TP group was reduced. Western blotting showed that the expression of LC3-II/I and Beclin-1 increased obviously, whereas the expression of SQSTM1/p62 was decreased in the DCM and OB-TP groups (P<0.05). CONCLUSIONS Tea polyphenols had an effect on diabetic cardiomyopathy in rat cardiac function and may alter the levels of autophagy to improve glucose and lipid metabolism in diabetes.
Animals ; Autophagy ; drug effects ; Beclin-1 ; analysis ; Blood Glucose ; analysis ; Body Weight ; Diabetic Cardiomyopathies ; drug therapy ; pathology ; physiopathology ; Lipids ; blood ; Male ; Myocardium ; pathology ; Polyphenols ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Tea ; chemistry

Diabetic cardiomyopathy (DCM) is characterized by left ventricular hypertrophy, myocardial fibrosis and diastolic dysfunction, which are uncorrelated with underlying coronary artery disease or hypertension. As an important metabolic organelle, mitochondria directly involve the process of cell growth, proliferation, signal transduction, apoptosis and so on. Recent studies have demonstrated a close correlation between the mitochondrial dysfunction and the pathogenesis of diabetic cardiomyopathy. The underlying effects of mitochondrial dysfunction in the progress of diabetic cardiomyopathy involve disturbed metabolism, oxidative stress, defective calcium handling, mitochondrial uncoupling, apoptosis, imbalance of mitochondrial quality control and regulation of MicroRNAs. Traditional Chinese medicines have been widely applied in clinic. Nowadays, more and more herbs of extracts of traditional Chinese medicines have been proved to ameliorate diabetic myocardial injury. Because the improvement of mitochondrial dysfunction has emerged as a promising therapeutic strategy, this review summarizes these effects of mitochondrial dysfunction in diabetic cardiomyopathy, and discusses the intervention studies of traditional Chinese medicine in the field, in expectation to provide new ideas for DCM prevention and treatment.
Diabetic Cardiomyopathies ; drug therapy ; pathology ; Drugs, Chinese Herbal ; therapeutic use ; Humans ; Medicine, Chinese Traditional ; Mitochondria ; pathology ; Myocardium