THBru attenuates diabetic cardiomyopathy by inhibiting RAGE-dependent inflammation.

Diabetic cardiomyopathy (DCM) is a complication of diabetes mellitus characterized by heart failure and cardiac remodeling. Previous studies show that tetrahydroberberrubine (THBru) retrogrades cardiac aging by promoting PHB2-mediated mitochondrial autophagy and prevents peritoneal adhesion by suppressing inflammation. In this study we investigated whether THBru exerted protective effect against DCM in db/db mice and potential mechanisms. Eight-week-old male db/db mice were administered THBru (25, 50 mg·kg-1·d-1, i.g.) for 12 weeks. Cardiac function was assessed using echocardiography. We showed that THBru administration significantly improved both cardiac systolic and diastolic function, as well as attenuated cardiac remodeling in db/db mice. In primary neonatal mouse cardiomyocytes (NMCMs), THBru (20, 40 µM) dose-dependently ameliorated high glucose (HG)-induced cell damage, hypertrophy, inflammatory cytokines release, and reactive oxygen species (ROS) production. Using Autodock, surface plasmon resonance (SPR) and DARTS analyses, we revealed that THBru bound to the domain of the receptor for advanced glycosylation end products (RAGE), subsequently leading to inactivation of the PI3K/AKT/NF-κB pathway. Importantly, overexpression of RAGE in NMCMs reversed HG-induced inactivation of the PI3K/AKT/NF-κB pathway and subsequently counteracted the beneficial effects mediated by THBru. We conclude that THBru acts as an inhibitor of RAGE, leading to inactivation of the PI3K/AKT/NF-κB pathway. This action effectively alleviates the inflammatory responses and oxidative stress in cardiomyocytes, ultimately leading to ameliorated DCM.

Epicardial Adipose Tissue is Associated with Geometry Alteration and Diastolic Dysfunction in Prediabetic Cardiomyopathy.

BACKGROUND: Diastolic dysfunction and alterations in cardiac geometry are early indicators of diabetic cardiomyopathy. However, the association between cardiac changes across the glucose continuum and the contribution of epicardial adipose tissue (EAT) to these changes has not yet been investigated. PURPOSE: In this study, we aim to investigated the EAT on cardiac diastolic function and structural alterations along the diabetic continuum using cardiac magnetic resonance imaging (CMRI). METHODS: We enrolled individuals who were categorized into groups based on glucose tolerance status. Left ventricular structure and diastolic function were assessed using echocardiography and CMRI to determine the EAT, intramyocardial fat, and associated parameters. Multivariable logistic regression models were also used. RESULTS: In a study of 370 patients (209 normal glucose tolerance, 82 prediabetes, 79 diabetes), those with prediabetes and diabetes showed increased heart dimensions and diastolic dysfunction, including E/E' (the ratio of early mitral inflow velocity to mitral annular early diastolic velocity) (7.9±0.51 vs. 8.5±0.64 vs. 10.0±0.93, p=0.010), left atrial volume index (28.21±14.7 vs. 33.2±12.8 vs. 37.4±8.2 mL/m2, p<0.001), and left ventricular peak filling rate (4.46±1.75 vs. 3.61±1.55 vs. 3.20±1.30 mL/s, p<0.001). EAT significantly increased in prediabetes and diabetes (26.3±1.16 vs. 31.3±1.83 vs. 33.9±1.9 gm, p=0.001), while intramyocardial fat did not differ significantly. Prediabetes altered heart geometry, but not diastolic function (OR 1.22 [1.02-1.83], p=0.012; and 1.70 [0.79-3.68], p=0.135). Diabetes significantly affected both heart structure and diastolic function (OR 1.42 [1.11-1.97], p=0.032; and 2.56 [1.03-5.40], p=0.034) after adjusting for covariates. CONCLUSIONS: Elevated EAT was observed in patients with prediabetes and is associated with adverse alterations in cardiac structure and diastolic function, potentially serving as an underlying mechanism for the early onset of diabetic cardiomyopathy.

Targeting Rab7-Rilp Mediated Microlipophagy Alleviates Lipid Toxicity in Diabetic Cardiomyopathy.

Diabetic cardiomyopathy (DbCM) is characterized by diastolic dysfunction, which progresses into heart failure and aberrant electrophysiology in diabetic patients. Dyslipidemia in type 2 diabetic patients leads to the accumulation of lipid droplets (LDs) in cardiomyocytes and results in lipid toxicity which has been suggested to drive DbCM. It is aimed to explore potential pathways that may boost LDs degradation in DbCM and restore cardiac function. LDs accumulation resulted in an increase in lipid toxicity in DbCM hearts is confirmed. Microlipophagy pathway, rather than traditional macrolipophagy, is activated in DbCM hearts. RNA-Seq data and Rab7-CKO mice implicate that Rab7 is a major modulator of the microlipophagy pathway. Mechanistically, Rab7 is phosphorylated at Tyrosine 183, which allows the recruitment of Rab-interacting lysosome protein (Rilp) to proceed LDs degradation by lysosome. Treating DbCM mice with Rab7 activator ML-098 enhanced Rilp level and rescued the observed cardiac dysfunction. Overall, Rab7-Rilp-mediated microlipophagy may be a promising target in the treatment of lipid toxicity in DbCM is suggested.

The relationship between endothelial-dependent flow-mediated dilation and diastolic function in type 2 diabetes.

AIMS: Diastolic dysfunction represents the earliest and most common manifestation of diabetic cardiomyopathy. Nitric oxide (NO), a potent vasodilator and anti-inflammatory mediator released from the subendocardial and coronary endothelium, favors left ventricular distensibility and relaxation. In type 2 diabetes (T2D), the NO bioavailability is reduced due to the oxidative stress and inflammatory state of the endothelium, because of chronic hyperglycemia. The aim of the present research is to evaluate the relationship between endothelial function and diastolic function in subjects with T2D. METHOD: Subjects with T2D and age and sex-matched healthy controls were consecutively recruited. All participants underwent flow-mediated dilation (FMD) to assess endothelial function, and echocardiography to evaluate diastolic function. RESULTS: Thirty-five patients (6 women, 29 men) and 35 healthy controls were included in the final analysis. FMD was significantly lower in T2D than controls (4.4 ± 3.4 vs. 8.5 ± 4.3%, p = 0.001). T2D presented different abnormalities in diastolic function compared to controls: lower E/A (early to late diastolic transmitral flow velocity), lower septal and lateral e' (early diastolic myocardial tissue velocity at septum and lateral wall), and higher E/e' (surrogate of filling pressure). In subjects with T2D, we observed a significant correlation between FMD and E/e' (r = -0.63, p = 0.001), lateral e' (r = 0.44, p = 0.03), and septal e' (r = 0.39, p = 0.05). CONCLUSIONS: Our observational study demonstrated a link between FMD and diastolic dysfunction in subjects with type 2 diabetes.

Farrerol Alleviates Diabetic Cardiomyopathy by Regulating AMPK-Mediated Cardiac Lipid Metabolic Pathways in Type 2 Diabetic Rats.

Diabetic cardiomyopathy (DCM) is a prevalent complication of diabetes mellitus characterized by cardiac dysfunction and myocardial remodeling. Farrerol (FA), an active ingredient in Rhododendron with various pharmacological activities, has an unclear specific role in DCM. Therefore, this study aims to investigate the effects of FA on DCM rats and elucidate its mechanism. The type 2 diabetes mellitus (T2DM) model was induced in adult male Sprague-Dawley rats by administering a high-fat diet for 8 weeks along with STZ injection. Subsequent to successful modeling, FA and the positive drug Dapagliflozin (Dapa) were orally administered via gavage for an additional 8-week period. After administration, the rats' body weight, fasting blood glucose, fasting insulin, and blood lipid profiles were quantified. Cardiac function was assessed through evaluation of cardiac function parameters, histopathological examination and measurement of myocardial enzyme markers were conducted to assess myocardial injury and fibrosis, Oil red O staining was utilized to evaluate myocardial lipid accumulation, wheat germ agglutinin (WGA) staining was used for assessing cardiomyocyte hypertrophy, and Western blot analysis was used to detect the proteins expression level of AMP-activated protein kinase (AMPK) pathway. The rat cardiomyocyte H9c2 were induced with palmitic acid to establish an in vitro cell model of myocardial lipid toxicity. Subsequently, the cells were subjected to treatment with FA and AMPK inhibitor Compound C, followed by assessment of lipid formation and expression levels of proteins related to the AMPK signaling pathway. The findings demonstrated that both FA and Dapa exhibited efficacy in ameliorating diabetic symptoms, cardiac dysfunction, myocardial fibrosis, cardiomyocyte hypertrophy, and lipid accumulation in T2DM rats. Additionally, they were found to enhance AMPK phosphorylation and PPARα expression while down-regulating CD36. Similarly, FA was observed to inhibit lipid formation in H9c2 and activate the AMPK signaling pathway. However, the improved effect of FA on lipotoxic cardiomyocytes induced by palmitic acid was partially reversed by Compound C. Therefore, the activation of the AMPK signaling pathway by FA may enhance cardiac lipid metabolism, thereby improving cardiac dysfunction and myocardial fibrosis in DCM rats.

Role of 8-hydroxyguanine DNA glycosidase 1 deficiency in exacerbating diabetic cardiomyopathy through the regulation of insulin resistance.

Diabetic cardiomyopathy (DCM) is a heart failure syndrome, and is one of the major causes of morbidity and mortality in diabetes. DCM is mainly characterized by ventricular dilation, myocardial hypertrophy, myocardial fibrosis and cardiac dysfunction. Clinical studies have found that insulin resistance is an independent risk factor for DCM. However, its specific mechanism of DCM remains unclear. 8-hydroxyguanine DNA glycosylase 1(OGG1)is involved in DNA base repair and the regulation of inflammatory genes. In this study, we show that OGG1 was associated with the occurrence of DCM. for the first time. The expression of OGG1 was increased in the heart tissue of DCM mice, and OGG1 deficiency aggravated the cardiac dysfunction of DCM mice. Metabolomics show that OGG1 deficiency resulted in obstruction of glycolytic pathway. At the molecular level, OGG1 regulated glucose uptake and insulin resistance by interacting with PPAR-γ in vitro. In order to explore the protective effect of exogenous OGG1 on DCM, OGG1 adeno-associated virus was injected into DCM mice through tail vein in the middle stage of the disease. We found that the overexpression of OGG1 could improve cardiac dysfunction of DCM mice, indicating that OGG1 had a certain therapeutic effect on DCM. These results demonstrate that OGG1 is a new molecular target for the treatment of DCM and has certain clinical significance.

Extracellular Vesicles in Diabetic Cardiomyopathy-State of the Art and Future Perspectives.

Cardiovascular complications are the most deadly and cost-driving effects of diabetes mellitus (DM). One of them, which is steadily attracting attention among scientists, is diabetes-induced heart failure, also known as diabetic cardiomyopathy (DCM). Despite significant progress in the research concerning the disease, a universally accepted definition is still lacking. The pathophysiology of the processes accelerating heart insufficiency in diabetic patients on molecular and cellular levels also remains elusive. However, the recent interest concerning extracellular vesicles (EVs) has brought promise to further clarifying the pathological events that lead to DCM. In this review, we sum up recent investigations on the involvement of EVs in DCM and show their therapeutic and indicatory potential.

Overexpression of MD1 ameliorates pathological myocardial remodeling in diabetic cardiomyopathy by TLR4/STAT3 signaling pathway.

Diabetic cardiomyopathy (DCM) is characterized by oxidative damage and inflammatory responses. Myeloid differentiation protein 1 (MD1) exhibits antioxidant and anti-inflammatory properties. However, the specific role of MD1 in DCM has yet to be elucidated. This study aims to investigate the role of MD1 in DCM and to elucidate the underlying mechanisms. We utilized a gain-of-function approach to explore the involvement of MD1 in DCM. Diabetes was induced in MD1-transgenic (MD1-TG) mice and their wild-type (WT) counterparts via streptozotocin (STZ) injection. Additionally, a diabetes cell model was established using H9c2 cells exposed to high glucose levels. We conducted comprehensive evaluations, including pathological analyses, echocardiography, electrocardiography, and molecular assessments, to elucidate the underlying mechanisms of MD1 in DCM. Notably, MD1 expression was reduced in the hearts of STZ-induced diabetic mice. Overexpression of MD1 significantly improved cardiac function and markedly inhibited ventricular pathological hypertrophy and fibrosis in these mice. Furthermore, MD1 overexpression resulted in a substantial decrease in myocardial reactive oxygen species (ROS) accumulation, mitigating myocardial oxidative stress and reducing the levels of inflammation-related markers such as IL-1ß, IL-6, and TNF-α. Mechanistically, MD1 overexpression inhibited the activation of the TLR4/STAT3 signaling pathway, as demonstrated in both in vivo and in vitro experiments. The overexpression of MD1 significantly impeded pathological cardiac remodeling and improved cardiac function in STZ-induced diabetic mice. This effect was primarily attributed to a reduction in ROS accumulation and mitigation of myocardial oxidative stress and inflammation, facilitated by the inhibition of the TLR4/STAT3 signaling pathway.

BRG1 Deficiency Promotes Cardiomyocyte Inflammation and Apoptosis by Activating the cGAS-STING Signaling in Diabetic Cardiomyopathy.

Brahma-related gene 1 (BRG1) has been implicated in the repair of DNA double-strand breaks (DSBs). Downregulation of BRG1 impairs DSBs repair leading to accumulation of double-stranded DNA (dsDNA). Currently, the role of BRG1 in diabetic cardiomyopathy (DCM) has not been clarified. In this study, we aimed to explore the function and molecular by which BRG1 regulates DCM using mice and cell models. We found that BRG1 was downregulated in the cardiac tissues of DCM mice and in cardiomyocytes cultured with high glucose and palmitic acid (HG/PA), which was accompanied by accumulation of dsDNA and activation of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway. shRNA-mediated Brg1 knockdown aggravated DCM mice cardiac functions, enhanced dsDNA accumulation, cGAS-STING signaling activation, which induced inflammation and apoptosis. In addition, the results were further verified in HG/PA-treated primary neonatal rat cardiomyocytes (NRCMs). Overexpression of BRG1 in NRCMs yielded opposite results. Furthermore, a selective cGAS inhibitor RU.521 or STING inhibitor C-176 partially reversed the BRG1 knockdown-induced inflammation and apoptosis in vitro. In conclusion, our results demonstrate that BRG1 is downregulated during DCM in vivo and in vitro, resulting in cardiomyocyte inflammation and apoptosis due to dsDNA accumulation and cGAS-STING signaling activation. Therefore, targeting the BRG1-cGAS-STING pathway may represent a novel therapeutic strategy for improving cardiac function of patients with DCM.

Naringin: Cardioprotective properties and safety profile in diabetes treatment.

Flavonoids derived from plants offer a broad spectrum of therapeutic potential for addressing metabolic syndrome, particularly diabetes mellitus (DM), a prevalent non-communicable disease. Hyperglycemia in DM is a known risk factor for cardiovascular diseases (CVDs), which substantially impact global mortality rates. This review examines the potential effects of naringin, a citrus flavonoid, on both DM and its associated cardiovascular complications, including conditions like diabetic cardiomyopathy. The safety profile of naringin is summarized based on various pre-clinical studies. The data for this review was gathered from diverse electronic databases, including Medline, PubMed, ScienceDirect, SpringerLink, Google Scholar, and Emerald Insight. Multiple pre-clinical studies have demonstrated that naringin exerts hypoglycemic and cardioprotective effects by targeting various vascular mechanisms. Specifically, research indicates that naringin down-regulates the renin-angiotensin and oxidative stress systems while concurrently upregulating ß-cell and immune system functions. Clinical trial outcomes also support the therapeutic potential of naringin in managing hyperglycemic states and associated cardiovascular issues. Moreover, toxicity studies have confirmed the safety of naringin in animal models, suggesting its potential for safe administration in humans. In conclusion, naringin emerges as a promising natural candidate for both antidiabetic and cardioprotective purposes, offering potential improvements in health outcomes. While naringin presents a new avenue for therapies targeting DM and CVDs, additional controlled and long-term clinical trials are necessary to validate its efficacy and safety for human use.

Quercetin Ameliorates Myocardial Injury in Diabetic Rats by Regulating Autophagy and Apoptosis through AMPK/mTOR Signaling Pathway.

A high-glucose environment is involved in the progression of diabetes mellitus (DM). This study aims to explore the regulatory effects of quercetin (QUE) on autophagy and apoptosis after myocardial injury in rats with DM. The type 2 DM rat models were constructed using low-dose streptozotocin (STZ) treatment combined with a high-carbohydrate (HC) diet in vivo. Compared with the control group, the body weight was decreased, whereas blood pressure, blood glucose, and the LVW/BW ratio were increased in the diabetic group. The results showed that the myocardial fibers were disordered in the diabetic group. Moreover, we found that the myocardial collagen fibers, PAS-positive cells, and apoptosis were increased, whereas the mitochondrial structure was destroyed and autophagic vacuoles were significantly reduced in the diabetic group compared with the control group. The expression levels of autophagy-related proteins LC3 and Beclin1 were decreased, whereas the expression levels of P62, Caspae-3, and Bax/Bcl-2 were increased in the diabetic group in vitro and in vivo. Moreover, QUE treatment alleviated the cellular oxidative stress reaction under high-glucose environments. The results of immunoprecipitation (IP) showed that the autophagy protein Beclin1 was bound to Bcl-2, and the binding capacity increased in the HG group, whereas it decreased after QUE treatment, suggesting that QUE inhibited the binding capacity between Beclin1 and Bcl-2, thus leading to the preservation of Beclin1-induced autophagy. In addition, the blood pressure, blood glucose, and cardiac function of rats were improved following QUE treatment. In conclusion, QUE suppressed diabetic myocardial injury and ameliorated cardiac function by regulating myocardial autophagy and inhibition of apoptosis in diabetes through the AMPK/mTOR signaling pathway.

[Mechanism of Shexiang Tongxin Dropping Pills in treating diabetic cardiomyopathy based on network pharmacology and animal experiments].

This study aimed to explore the mechanism of Shexiang Tongxin Dropping Pills(STDP) in treating diabetic cardiomyopathy(DCM) based on network pharmacology, molecular docking, and animal experiments. BATMAN, TCMSP, and GeneCards were searched for the active ingredients and targets of STDP against DCM. STRING and Cytoscape were used to build the protein-protein interaction(PPI) network and "drug-active ingredient-target" network. Gene Ontology(GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analysis of the targets were carried out based on DAVID. The molecular docking of key receptor proteins with corresponding active ingredients was performed using AutoDock Vina. The rat model of DCM was established by a high-fat diet combined with intraperitoneal injection of streptozotocin. Rats were assigned into control, model, low-(20 mg·kg~(-1)) and high-dose(40 mg·kg~(-1)) STDP, and metformin(200 mg·kg~(-1)) groups. After 8 weeks of continuous administration, the cardiac function, myocardial pathological changes, and myocardial collagen fiber deposition of rats in each group were detected by echocardiography, hematoxylin-eosin(HE) staining, and Sirius red staining, respectively. The myocardial hypertrophy was detected by WGA staining. The expression levels of p38 mitogen-activated protein kinase(p38), phosphorylation-p38(p-p38), c-Jun N-terminal kinase(JNK), phosphorylation-JNK(p-JNK), caspase-3, and C-caspase-3 in the myocardial tissue of rats in each group were measured by Western blot. The network pharmacology predicted 199 active ingredients and 1 655 targets of STDP and 463 targets of DCM. One hundred and thirty-four potential targets of STDP for treating DCM were obtained, and the AGE-RAGE signaling pathway in diabetic complications was screened out. Molecular docking results showed that miltirone, dehydromiltirone, and tryptanthrin had strong binding affinity with RAGE. The results of animal experiments confirmed that STDP effectively protected the cardiac function of DCM rats. Compared with the DCM model group, the STDP groups showed significantly down-regulated protein levels of p-p38, p-JNK, and C-caspase-3. To sum up, STDP may protect the cardiac function of DCM rats by regulating the AGE-RAGE signaling pathway.

JinLiDa granules alleviates cardiac hypertrophy and inflammation in diabetic cardiomyopathy by regulating TP53.

BACKGROUND: JinLiDa granules (JLD) is a traditional Chinese medicine (TCM) used to treat type 2 diabetes mellitus with Qi and Yin deficiency. Clinical evidence has shown that JLD can alleviate diabetic cardiomyopathy, but the exact mechanism is not yet clear. PURPOSE: The purpose of this study was to examine the potential role and mechanism of JLD in the treatment of diabetic cardiomyopathy through network pharmacological analysis and basic experiments. METHODS: The targets of JLD associated with diabetic cardiomyopathy were examined by network pharmacology. Protein interaction analysis was performed on the targets, and the associated pathways were searched by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Diabetic mice were treated with low or high doses of JLD by gavage, and AC16 and H9C2 cardiomyocytes exposed to high-glucose conditions were treated with JLD. The analysis results were verified by various experimental techniques to examine molecular mechanisms. RESULTS: Network pharmacological analysis revealed that JLD acted on the tumor suppressor p53 (TP53) during inflammation and fibrosis associated with diabetic cardiomyopathy. The results of basic experiments showed that after JLD treatment, ventricular wall thickening in diabetic mouse hearts was attenuated, cardiac hypertrophy and myocardial inflammation were alleviated, and the expression of cardiac hypertrophy- and inflammation-related factors in cardiomyocytes exposed to a high-glucose environment was decreased. Cardiomyocyte morphology also improved after JLD treatment. TP53 expression and the tumor necrosis factor (TNF) and transforming growth factor beta-1 (TGFß1) signaling pathways were significantly altered, and inhibiting TP53 expression effectively alleviated the activation of the TNF and TGFß1 signaling pathways under high glucose conditions. Overexpression of TP53 activated these signaling pathways. CONCLUSIONS: JLD acted on TP53 to regulate the TNF and TGFß1 signaling pathways, effectively alleviating cardiomyocyte hypertrophy and inflammation in high glucose and diabetic conditions. Our study provides a solid foundation for the future treatment of diabetic cardiomyopathy with JLD.

Bone morphogenetic protein 10, a rising star in the field of diabetes and cardiovascular disease.

Early research suggested that bone morphogenetic protein 10 (BMP10) is primarily involved in cardiac development and congenital heart disease processes. BMP10 is a newly identified cardiac-specific protein. In recent years, reports have emphasized the effects of BMP10 on myocardial apoptosis, fibrosis and immune response, as well as its synergistic effects with BMP9 in vascular endothelium and role in endothelial dysfunction. We believe that concentrating on this aspect of the study will enhance our knowledge of the pathogenesis of diabetes and the cardiovascular field. However, there have been no reports of any reviews discussing the role of BMP10 in diabetes and cardiovascular disease. In addition, the exact pathogenesis of diabetic cardiomyopathy is not fully understood, including myocardial energy metabolism disorders, microvascular changes, abnormal apoptosis of cardiomyocytes, collagen structural changes and myocardial fibrosis, all of which cause cardiac function impairment directly or indirectly and interact with one another. This review summarizes the research results of BMP10 in cardiac development, endothelial function and cardiovascular disease in an effort to generate new ideas for future research into diabetic cardiomyopathy.

Sirt5 improves cardiomyocytes fatty acid metabolism and ameliorates cardiac lipotoxicity in diabetic cardiomyopathy via CPT2 de-succinylation.

RATIONALE: The disruption of the balance between fatty acid (FA) uptake and oxidation (FAO) leads to cardiac lipotoxicity, serving as the driving force behind diabetic cardiomyopathy (DbCM). Sirtuin 5 (Sirt5), a lysine de-succinylase, could impact diverse metabolic pathways, including FA metabolism. Nevertheless, the precise roles of Sirt5 in cardiac lipotoxicity and DbCM remain unknown. OBJECTIVE: This study aims to elucidate the role and underlying mechanism of Sirt5 in the context of cardiac lipotoxicity and DbCM. METHODS AND RESULTS: The expression of myocardial Sirt5 was found to be modestly elevated in diabetic heart failure patients and mice. Cardiac dysfunction, hypertrophy and lipotoxicity were exacerbated by ablation of Sirt5 but improved by forced expression of Sirt5 in diabetic mice. Notably, Sirt5 deficiency impaired FAO without affecting the capacity of FA uptake in the diabetic heart, leading to accumulation of FA intermediate metabolites, which mainly included medium- and long-chain fatty acyl-carnitines. Mechanistically, succinylomics analyses identified carnitine palmitoyltransferase 2 (CPT2), a crucial enzyme involved in the reconversion of fatty acyl-carnitines to fatty acyl-CoA and facilitating FAO, as the functional succinylated substrate mediator of Sirt5. Succinylation of Lys424 in CPT2 was significantly increased by Sirt5 deficiency, leading to the inactivation of its enzymatic activity and the subsequent accumulation of fatty acyl-carnitines. CPT2 K424R mutation, which mitigated succinylation modification, counteracted the reduction of enzymatic activity in CPT2 mediated by Sirt5 deficiency, thereby attenuating Sirt5 knockout-induced FAO impairment and lipid deposition. CONCLUSIONS: Sirt5 deficiency impairs FAO, leading to cardiac lipotoxicity in the diabetic heart through the succinylation of Lys424 in CPT2. This underscores the potential roles of Sirt5 and CPT2 as therapeutic targets for addressing DbCM.

Investigation of crucial genes and mitochondrial function impairment in diabetic cardiomyopathy.

BACKGROUND: Diabetic cardiomyopathy (DCM) is a special type of cardiovascular disease, termed as a situation of abnormal myocardial structure and function that occurs in diabetic patients. However, the most fundamental mechanisms of DCM have not been fully explicated, and useful targets for the therapeutic strategies still need to be explored. METHODS: In the present study, we combined bioinformatics analysis and in vitro experiments throughout the process of DCM. Differentially Expressed Genes (DEGs) analysis was performed and the weighted gene co-expression network analysis (WGCNA) was constructed to determine the crucial genes that were tightly connected to DCM. Additionally, Functional enrichment analysis was conducted to define biological pathways. To identify the specific molecular mechanism, the human cardiomyocyte cell line (AC16) was stimulated by high glucose (HG, 50 mM D-glucose) and used to imitate DCM condition. Then, we tentatively examined the effect of high glucose on cardiomyocytes, the expression levels of crucial genes were further validated by in vitro experiments. RESULTS: Generally, NPPA, IGFBP5, SERPINE1, and C3 emerged as potential therapeutic targets. Functional enrichment analysis performed by bioinformatics indicated that the pathogenesis of DCM is mainly related to heart muscle contraction and calcium (Ca2+) release activation. In vitro, we discovered that high glucose treatment induced cardiomyocyte injury and exacerbated mitochondrial dysfunction remarkably. CONCLUSION: Our research defined four crucial genes, as well as determined that mitochondrial function impairment compromises calcium homeostasis ultimately resulting in contractile dysfunction is a central contributor to DCM progression. Hopefully, this study will offer more effective biomarkers for DCM diagnosis and treatment.

USP7 promotes cardiometabolic disorders and mitochondrial homeostasis dysfunction in diabetic mice via stabilizing PGC1ß.

Diabetic cardiomyopathy (DCM) is a major complication of diabetes and is characterized by left ventricular dysfunction. Currently, there is a lack of effective treatments for DCM. Ubiquitin-specific protease 7 (USP7) plays a key role in various diseases. However, whether USP7 is involved in DCM has not been established. In this study, we demonstrated that USP7 was upregulated in diabetic mouse hearts and NMCMs co-treated with HG+PA or H9c2 cells treated with PA. Abnormalities in diabetic heart morphology and function were reversed by USP7 silencing through conditional gene knockout or chemical inhibition. Proteomic analysis coupled with biochemical validation confirmed that PCG1ß was one of the direct protein substrates of USP7 and aggravated myocardial damage through coactivation of the PPARα signaling pathway. USP7 silencing restored the expression of fatty acid metabolism-related proteins and restored mitochondrial homeostasis by inhibiting mitochondrial fission and promoting fusion events. Similar effects were also observed in vitro. Our data demonstrated that USP7 promoted cardiometabolic metabolism disorders and mitochondrial homeostasis dysfunction via stabilizing PCG1ß and suggested that silencing USP7 may be a therapeutic strategy for DCM.

Therapeutic strategies targeting mechanisms of macrophages in diabetic heart disease.

Diabetic heart disease (DHD) is a serious complication in patients with diabetes. Despite numerous studies on the pathogenic mechanisms and therapeutic targets of DHD, effective means of prevention and treatment are still lacking. The pathogenic mechanisms of DHD include cardiac inflammation, insulin resistance, myocardial fibrosis, and oxidative stress. Macrophages, the primary cells of the human innate immune system, contribute significantly to these pathological processes, playing an important role in human disease and health. Therefore, drugs targeting macrophages hold great promise for the treatment of DHD. In this review, we examine how macrophages contribute to the development of DHD and which drugs could potentially be used to target macrophages in the treatment of DHD.

Interleukin 1ß receptor blocker (Anakinra) and regenerative stem cell therapy: two novel approaches effectively ameliorating diabetic cardiomyopathy.

Diabetic cardiomyopathy (DCM) is a serious common complication of diabetes. Unfortunately, there is no satisfied treatment for those patients and more studies are in critical need to cure them. Therefore, we aimed to carry out our current research to explore the role of two novel therapeutic approaches: one a biological drug aimed to block inflammatory signaling of the IL 1beta (IL1ß) axis, namely, anakinra; the other is provision of anti-inflammatory regenerative stem cells. Wistar male rats were allocated into four groups: control group: type 2 diabetes mellitus (DM) induced by 6-week high-fat diet (HFD) followed by a single-dose streptozotocin (STZ) 35 mg/kg i.p., then rats were allocated into: DM: untreated; DM BM-MSCs: received a single dose of BM-MSCs (1 × 106 cell/rat) into rat tail vein; DM-Anak received Anak 0.5 µg/kg/day i.p. for 2 weeks. Both therapeutic approaches improved cardiac performance, fibrosis, and hypertrophy. In addition, blood glucose and insulin resistance decreased, while the antioxidant parameter, nuclear factor erythroid 2-related factor 2 (Nrf2) and interleukin 10 (IL10), and anti-inflammatory agent increased. Furthermore, there is a significant reduction in tumor necrosis factor alpha (TNFα), IL1ß, caspase1, macrophage marker CD 11b, inducible nitric oxide synthase (iNOS), and T-cell marker CD 8. Both Anak and BM-MSCs effectively ameliorated inflammatory markers and cardiac performance as compared to non-treated diabetics. Improvement is mostly due to anti-inflammatory, antioxidant, anti-apoptotic properties, and regulation of TNFα/IL1ß/caspase1 and Nrf2/IL10 pathways.

Patchouli Alcohol Protects the Heart against Diabetes-Related Cardiomyopathy through the JAK2/STAT3 Signaling Pathway.

Diabetic cardiomyopathy (DCM) represents a common pathological state brought about by diabetes mellitus (DM). Patchouli alcohol (PatA) is known for its diverse advantageous effects, notably its anti-inflammatory properties and protective role against metabolic disorders. Despite this, the influence of PatA on DCM remains relatively unexplored. To explore the effect of PatA on diabetes-induced cardiac injury and dysfunction in mice, streptozotocin (STZ) was used to mimic type 1 diabetes in mice. Serological markers and echocardiography show that PatA treatment protects the heart against cardiomyopathy by controlling myocardial fibrosis but not by reducing hyperglycemia in diabetic mice. Discovery Studio 2017 software was used to perform reverse target screening of PatA, and we found that JAK2 may be a potential target of PatA. RNA-seq analysis of heart tissues revealed that PatA activity in the myocardium was primarily associated with the inflammatory fibrosis through the Janus tyrosine kinase 2 (JAK2)/signal transducer and activator of the transcription 3 (STAT3) pathway. In vitro, we also found that PatA alleviates high glucose (HG) + palmitic acid (PA)-induced fibrotic and inflammatory responses via inhibiting the JAK2/STAT3 signaling pathway in H9C2 cells. Our findings illustrate that PatA mitigates the effects of HG + PA- or STZ-induced cardiomyopathy by acting on the JAK2/STAT3 signaling pathway. These insights indicate that PatA could potentially serve as a therapeutic agent for DCM treatment.