Macrod1 suppresses diabetic cardiomyopathy via regulating PARP1-NAD+-SIRT3 pathway.

Diabetic cardiomyopathy (DCM), one of the most serious long-term consequences of diabetes, is closely associated with oxidative stress, inflammation and apoptosis in the heart. MACRO domain containing 1 (Macrod1) is an ADP-ribosylhydrolase 1 that is highly enriched in mitochondria, participating in the pathogenesis of cardiovascular diseases. In this study, we investigated the role of Macrod1 in DCM. A mice model was established by feeding a high-fat diet (HFD) and intraperitoneal injection of streptozotocin (STZ). We showed that Macrod1 expression levels were significantly downregulated in cardiac tissue of DCM mice. Reduced expression of Macrod1 was also observed in neonatal rat cardiomyocytes (NRCMs) treated with palmitic acid (PA, 400 µM) in vitro. Knockout of Macrod1 in DCM mice not only worsened glycemic control, but also aggravated cardiac remodeling, mitochondrial dysfunction, NAD+ consumption and oxidative stress, whereas cardiac-specific overexpression of Macrod1 partially reversed these pathological processes. In PA-treated NRCMs, overexpression of Macrod1 significantly inhibited PARP1 expression and restored NAD+ levels, activating SIRT3 to resist oxidative stress. Supplementation with the NAD+ precursor Niacin (50 µM) alleviated oxidative stress in PA-stimulated cardiomyocytes. We revealed that Macrod1 reduced NAD+ consumption by inhibiting PARP1 expression, thereby activating SIRT3 and anti-oxidative stress signaling. This study identifies Macrod1 as a novel target for DCM treatment. Targeting the PARP1-NAD+-SIRT3 axis may open a novel avenue to development of new intervention strategies in DCM. Schematic illustration of macrod1 ameliorating diabetic cardiomyopathy oxidative stress via PARP1-NAD+-SIRT3 axis.

Chinese Medicine Supplementing Qi and Activating Blood Circulation Relieves the Progression of Diabetic Cardiomyopathy.

BACKGROUND: Diabetic cardiomyopathy (DCM) is the leading cause of diabetic death as the final occurrence of heart failure and arrhythmia. Traditional Chinese medicine is usually used to treat various diseases including diabetes. OBJECTIVE: This study sought to investigate the effects of Traditional Chinese medicine supplementing Qi and activating blood circulation (SAC) in DCM. METHODS: After the construction of the DCM model by streptozotocin (STZ) injection and high glucose/fat diet feeding, rats were administered intragastrically with SAC. Then, cardiac systolic/diastolic function was evaluated by detecting left ventricular systolic pressure (LVSP), maximal rate of left ventricular pressure rise (+LVdp/dtmax), and fall (-LVdp/dtmax), heart rate (HR), left ventricular ejection fraction (EF), LV fractional shortening (FS) and left ventricular end-diastolic pressure (LVEDP). Masson's and TUNEL staining were used to assess fibrosis and cardiomyocyte apoptosis. RESULTS: DCM rats exhibited impaired cardiac systolic/diastolic function manifested by decreasing LVSP, + LVdp/dtmax, -LVdp/dtmax, HR, EF and FS, and increasing LVEDP. Intriguingly, traditional Chinese medicine SAC alleviated the above-mentioned symptoms, indicating a potential role in improving cardiac function. Masson's staining substantiated that SAC antagonized the increased collagen deposition and interstitial fibrosis area and the elevations in protein expression of fibrosisrelated collagen I and fibronectin in heart tissues of DCM rats. Furthermore, TUNEL staining confirmed that traditional Chinese medicine SAC also attenuated cardiomyocyte apoptosis in DCM rats. Mechanically, DCM rats showed the aberrant activation of the TGF-ß/Smad signaling, which was inhibited after SAC. CONCLUSION: SAC may exert cardiac protective efficacy in DCM rats via the TGF-ß/Smad signaling, indicating a new promising therapeutic approach for DCM.

Impacts of trelagliptin and remogliflozin alone and in combination with Alpha Lipoic Acid on cardiac function in streptozotocin-induced diabetes mellitus in rats.

This study investigated the effects of trelagliptin and remogliflozin, alone and in combination with alpha lipoic acid (ALA), on cardiac biomarkers in diabetic cardiomyopathy (DCM). We aimed to assess the management of glucotoxicity consequences in streptozotocin-induced diabetic rats by measuring serum levels of pharmacologically active endogenous ligands. Forty-eight male rats were divided into different treatment groups, including negative control, positive control, and four experimental groups. After inducing diabetes, the rats were treated for 28 days, and serum levels of biomarkers associated with oxidative stress (malondialdehyde and thioredoxin-interacting protein), inflammation (nuclear factor NF-kappa-B p105 and lipoprotein-associated phospholipase A2), and myopathy (neprilysin and high selective cardiac troponin T) were measured. Immunohistochemical analysis of heart cells was also performed. The results showed that inducing hyperglycemia increased serum glucose levels and biomarkers associated with DCM. However, all treatment groups exhibited a significant decrease in these biomarkers and an increase in insulin levels compared to the diabetic control group. The groups receiving combination therapy with ALA showed greater improvements in cardiac biomarkers compared to the individual treatments. The immunohistochemical analysis supported these findings by demonstrating a reduction in the percentage area of cathepsin B, a protein involved in DCM pathophysiology. In conclusion, supplementing the base treatments with ALA showed promise in enhancing cardiac biomarkers associated with DCM. The combination of trelagliptin, remogliflozin, and ALA may have additional clinical value in managing DCM by targeting oxidative stress, inflammation, and glucotoxicity. However, further research is needed to validate these findings and explore their potential clinical applications.

Targeting mitochondrial quality control for diabetic cardiomyopathy: Therapeutic potential of hypoglycemic drugs.

Diabetic cardiomyopathy is a chronic cardiovascular complication caused by diabetes that is characterized by changes in myocardial structure and function, ultimately leading to heart failure and even death. Mitochondria serve as the provider of energy to cardiomyocytes, and mitochondrial dysfunction plays a central role in the development of diabetic cardiomyopathy. In response to a series of pathological changes caused by mitochondrial dysfunction, the mitochondrial quality control system is activated. The mitochondrial quality control system (including mitochondrial biogenesis, fusion and fission, and mitophagy) is core to maintaining the normal structure of mitochondria and performing their normal physiological functions. However, mitochondrial quality control is abnormal in diabetic cardiomyopathy, resulting in insufficient mitochondrial fusion and excessive fission within the cardiomyocyte, and fragmented mitochondria are not phagocytosed in a timely manner, accumulating within the cardiomyocyte resulting in cardiomyocyte injury. Currently, there is no specific therapy or prevention for diabetic cardiomyopathy, and glycemic control remains the mainstay. In this review, we first elucidate the pathogenesis of diabetic cardiomyopathy and explore the link between pathological mitochondrial quality control and the development of diabetic cardiomyopathy. Then, we summarize how clinically used hypoglycemic agents (including sodium-glucose cotransport protein 2 inhibitions, glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase-4 inhibitors, thiazolidinediones, metformin, and α-glucosidase inhibitors) exert cardioprotective effects to treat and prevent diabetic cardiomyopathy by targeting the mitochondrial quality control system. In addition, the mechanisms of complementary alternative therapies, such as active ingredients of traditional Chinese medicine, exercise, and lifestyle, targeting mitochondrial quality control for the treatment of diabetic cardiomyopathy are also added, which lays the foundation for the excavation of new diabetic cardioprotective drugs.

Diabetic cardiomyopathy - Zinc preventive and therapeutic potentials by its anti-oxidative stress and sensitizing insulin signaling pathways.

Oxidative stress and insulin resistance are two key mechanisms for the development of diabetic cardiomyopathy (DCM, cardiac remodeling and dysfunction). In this review, we discussed how zinc and metallothionein (MT) protect the heart from type 1 or type 2 diabetes (T1D or T2D) through its anti-oxidative function and insulin-mediated PI3K/Akt signaling activation. Both T1D and T2D-induced DCM, shown by cardiac structural remodeling and dysfunction, in wild-type mice, but not in cardiomyocyte-specific overexpressing MT mice. In contrast, mice with global MT gene deletion were more susceptible to the development of DCM. When we used zinc to treat mice with either T1D or T2D, cardiac remodeling and dysfunction were significantly prevented along with increased cardiac MT expression. To support the role of zinc homeostasis in insulin signaling pathways, treatment of diabetic mice with zinc showed the preservation of phosphorylation levels of insulin-mediated glucose metabolism-related Akt2 and GSK-3ß and even rescued cardiac pathogenesis induced by global deletion of Akt2 gene in a MT-dependent manner. These results suggest the protection by zinc from DCM is through both the induction of MT and sensitization of insulin signaling. Combined our own and other works, this review comprehensively summarized the roles of zinc homeostasis in the development and progression of DCM and its therapeutic implications. At the end, we provided pre-clinical and clinical evidence for the preventive and therapeutic potential of zinc supplementation through its anti-oxidative stress and sensitizing insulin signaling actions. Understanding the intricate connections between zinc and DCM provides insights for the future interventional approaches.

ß-elemene alleviates hyperglycemia-induced cardiac inflammation and remodeling by inhibiting the JAK/STAT3-NF-κB pathway.

BACKGROUND: Hyperglycemic induced cardiac hypertrophy and cardiac inflammation are important pathological processes in diabetic cardiomyopathy. ß-elemene (Ele) is a natural compound extracted from Curcuma Rhizoma and has anti-tumor effects. It also has therapeutic effects in some inflammatory diseases. However, the therapeutic effect of Ele on diabetic cardiomyopathy is not clear. The purpose of this study was to evaluate the effect of Ele on hyperglycemia-caused cardiac remodeling and heart failure. METHODS: C57BL/6 mice were intraperitoneally injected with streptozotocin to induce DCM, and Ele was administered intragastric after 8 weeks to investigate the effect of Ele. RNA sequencing of cardiac tissue was performed to investigate the mechanism. RESULTS: Ele markedly inhibited cardiac inflammation, fibrosis and hypertrophy in diabetic mice, as well as in high glucose-induced cardiomyocytes. RNA sequencing showed that cardioprotective effect of Ele involved the JAK/STAT3-NF-κB signaling pathway. Ele alleviated heart and cardiomyocyte inflammation in mice by blocking diabetes-induced JAK2 and STAT3 phosphorylation and NF-κB activation. CONCLUSIONS: The study found that Ele preserved the hearts of diabetic mice by inhibiting JAK/STAT3 and NF-κB mediated inflammatory responses, suggesting that Ele is an effective therapy for DCM.

The Chinese herbal medicine Fufang Zhenzhu Tiaozhi ameliorates diabetic cardiomyopathy by regulating cardiac abnormal lipid metabolism and mitochondrial dynamics in diabetic mice.

Diabetic cardiomyopathy (DCM) is an important complication leading to the death of patients with diabetes, but there is no effective strategy for clinical treatments. Fufang Zhenzhu Tiaozhi (FTZ) is a patent medicine that is a traditional Chinese medicine compound preparation with comprehensive effects for the prevention and treatment of glycolipid metabolic diseases under the guidance of "modulating liver, starting pivot and cleaning turbidity". FTZ was proposed by Professor Guo Jiao and is used for the clinical treatment of hyperlipidemia. This study was designed to explore the regulatory mechanisms of FTZ on heart lipid metabolism dysfunction and mitochondrial dynamics disorder in mice with DCM, and it provides a theoretical basis for the myocardial protective effect of FTZ in diabetes. In this study, we demonstrated that FTZ protected heart function in DCM mice and downregulated the overexpression of free fatty acids (FFAs) uptake-related proteins cluster of differentiation 36 (CD36), fatty acid binding protein 3 (FABP3) and carnitine palmitoyl transferase 1 (CPT1). Moreover, FTZ treatment showed a regulatory effect on mitochondrial dynamics by inhibiting mitochondrial fission and promoting mitochondrial fusion. We also identified in vitro that FTZ could restore lipid metabolism-related proteins, mitochondrial dynamics-related proteins and mitochondrial energy metabolism in PA-treated cardiomyocytes. Our study indicated that FTZ improves the cardiac function of diabetic mice by attenuating the increase in fasting blood glucose levels, inhibiting the decrease in body weight, alleviating disordered lipid metabolism, and restoring mitochondrial dynamics and myocardial apoptosis in diabetic mouse hearts.

Salvianolic acid A improve mitochondrial respiration and cardiac function via inhibiting apoptosis pathway through CRYAB in diabetic cardiomyopathy.

Salvianolic acid A (SAA) is a traditional Chinese medicine that has a good therapeutic effect on cardiovascular disease. However, the underlying mechanisms by which SAA improves mitochondrial respiration and cardiac function in diabetic cardiomyopathy (DCM) remain unknown. This study aims to elucidate whether SAA had any cardiovascular protection on the pathophysiology of DCM and explored the potential mechanisms. Diabetes was induced in rats by 30 mg/kg of streptozotocin (STZ) treatment. After a week of stability, 5 mg/kg isoprenaline (ISO) was injected into the rats subcutaneously. 3 mg/kg SAA was orally administered for six weeks and 150 mg/kg Metformin was selected as a positive group. At the end of this period, cardiac function was assessed by ultrasound, electrocardiogram, and relevant cardiac injury biomarkers testing. Treatment with SAA improved cardiac function, glucose, and lipid levels, mitochondrial respiration, and suppressed myocardial inflammation and apoptosis. Furthermore, SAA treatment inhibits the apoptosis pathway through CRYAB in diabetic cardiomyopathy rats. As a result, this study not only provides new insights into the mechanism of SAA against DCM but also provides new therapeutic ideas for the discovery of anti-DCM compounds in the clinic.

The high-intensity interval training (HIIT) and curcumin supplementation can positively regulate the autophagy pathway in myocardial cells of STZ-induced diabetic rats.

OBJECTIVE: Targeting autophagy is a new therapeutic strategy for the complications of diabetes,such as diabetic cardiomyopathy (DCM). During diabetes, increased or insufficient autophagic activity causes aberrations in cellular homeostasis. Regarding the conflicting and unclear results regarding the effect of HIIT and curcumin supplementation on the expression of genes associated to autophagy, this study aimed to assess whether 4-week high-intensity interval training (HIIT) and curcumin supplementation are able to influence the expression of autophagy-related genes in myocardial cells of diabetic rats. METHODS: In an experimental design, 24 male Wistar rats were randomly divided into 4 groups: non-diabetic control (NC), diabetic control (DC), diabetes + HIIT (D + HIIT), and diabetes + curcumin (D + CU). After HIIT program and curcumin treatment, the genes expression of autophagy pathway were assessed in the myocardium by real-time PCR Tanique. RESULTS: The results indicated that the expression levels of ATG1, Beclin1, ATG5, and LAMP-2 genes were significantly reduced in the DC group compared to the NC group (p < 0.001). Following 4-week HIIT, the expression of Beclin1, ATG-5, and LAMP-2 improved considerably compared to the DC group (p < 0.001, p < 0.001, and p < 0.05, respectively). In addition, after 4 weeks of curcumin supplementation, the expression levels of ATG-5 and Beclin-1 were significantly improved compared to the DC group (p < 0.001, p < 0.05, respectively). It seems HIIT and curcumin supplementation can be an effective approach for inducing autophagy and improving cardiac function in DCM rats.However, HIIT seems more effective than curcumin in this regard.

Astragalus polysaccharides alleviates cardiac hypertrophy in diabetic cardiomyopathy via inhibiting the BMP10-mediated signaling pathway.

BACKGROUND: Cardiac hypertrophy can lead to cardiac dysfunction and is closely associated with mortality in diabetic cardiomyopathy (DCM). Astragalus polysaccharides (APS) is the main component extracted from Astragalus membranaceus (Fisch.) Bunge (AM), which exhibits anti-hypertrophic effects on cardiomyocytes in various diseases. However, whether APS exerts anti-hypertrophic effects in DCM remains unclear. PURPOSE: To investigate whether APS can attenuate cardiac hypertrophy in DCM and exert anti-hypertrophic effects by inhibiting the bone morphogenetic protein 10 (BMP10) pathway. METHODS: The anti-hypertrophic effects of APS were studied in high-glucose (HG)-stimulated H9c2 cardiomyocytes and streptozotocin (STZ)-induced DCM rats. BMP10 siRNA was used to inhibit BMP10 expression in H9c2 cardiomyocytes. Cardiac function was assessed by echocardiography. Cardiac hypertrophy was evaluated using heart weight/body weight (HW/BW), RT-PCR, hematoxylin-eosin (HE), and rhodamine phalloidin staining. Changes in hypertrophic components, including BMP10 and downstream factors, were measured using western blotting. RESULTS: In vitro, HG treatment increased the relative cell surface area of H9c2 cardiomyocytes, whereas BMP10 siRNA transfection or APS treatment alleviated the increase induced by HG. APS treatment improved the general condition, increased cardiac function, and decreased the HW/BW ratio, ANP mRNA level, and cardiomyocyte cross-sectional area of DCM rats in vivo. Molecular experiments demonstrated that APS downregulated the levels of the pro-hypertrophic protein BMP10 and its downstream proteins ALK3, BMPRII, and p-Smad1/5/8 without affecting the level of total Smad1/5/8. CONCLUSIONS: Our study demonstrates that APS can alleviate cardiac hypertrophy and protect against DCM by inhibiting activation of the BMP10 pathway. APS is a promising candidate for DCM treatment.

Independent and combined effects of liraglutide and aerobic interval training on glycemic control and cardiac protection in diabetic cardiomyopathy rats.

OBJECTIVE: This study intended to explore the hypoglycemic and cardioprotective effects of 8-week aerobic interval training combined with liraglutide and elucidate the underlying mechanisms. METHOD: Male Wistar rats were randomly divided into 5 groups - normal control group (CON), diabetic cardiomyopathy group (DCM), high-dose liraglutide group (DH), low-dose liraglutide group (DL), and aerobic interval training combined with liraglutide group (DLE). High-fat diet and streptozotocin (STZ) were used to induce the DCM model, and both the liraglutide administration group and combination therapy group allocated to 8 weeks of either liraglutide or liraglutide and exercise intervention. Cardiac functions were analyzed by electrocardiography. Blood biochemical parameters were measured to judge glycemic control conditions. Hematoxylin and eosin (HE) staining and Sirus red staining was used to identify cardiac morphology and collagen accumulation, respectively. Advanced glycation end products (AGEs) were determined by enzymatic methods. The mRNA expression of myocardial remodeling genes (BNP, GSK3ß, α-MHC, ß-MHC and PPARα) and the protein expression of GLP-1, GLP-1R were analyzed. RESULTS: DCM rats developed hyperglycemia, impaired cardiac function with accumulation of AGEs and collagen (P < 0.05). The development of hyperglycemia and cardiac dysfunction was significantly attenuated with all interventions, as reduced cardiac fibrosis and improved cardiac function (P < 0.05). Cardiac remodeling genes were normalized after all interventions, these positive modifications were due to increased GLP-1 and GLP-1R expression in DCM heart (P < 0.05). Liraglutide combined with AIT significantly increased the diameters of cardiomyocytes, increased the α-MHC expressionx, reduced PPARαexpression and reduced the fluctuation of blood glucose level, which showed the safety and effective of medicine combined with exercise. CONCLUSION: Liraglutide combined with AIT intervention normalized blood glucose alleviates myocardial fibrosis and improves cardiac contractile function in DCM rats, supporting the efficacy and safety of the combination therapy.

The Beneficial Effects of Chinese Herbal Monomers on Ameliorating Diabetic Cardiomyopathy via Nrf2 Signaling.

Diabetic cardiomyopathy (DCM) is the main factor responsible for poor prognosis and survival in patients with diabetes. The highly complex pathogenesis of DCM involves multiple signaling pathways, including nuclear factor-κB (NF-κB) signaling pathway, adenosine monophosphate-activated protein kinase (AMPK) signaling pathway, phosphatidylinositol 3-kinase-protein kinase B (Akt) signaling pathway, mitogen-activated protein kinase (MAPK) signaling pathway, and transforming growth factor-ß (TGF-ß) signaling pathway. Nuclear factor erythroid-2-related factor 2 (Nrf2) seems essential to the amelioration of the progression of DCM, not only through counterbalancing oxidative stress, but also through interacting with other signaling pathways to combat inflammation, the disorder in energy homeostasis and insulin signaling, and fibrosis. It has been evidenced that Chinese herbal monomers could attenuate DCM through the crosstalk of Nrf2 with other signaling pathways. This article has summarized the pathogenesis of DCM (especially in oxidative stress), the beneficial effects of ameliorating DCM via the Nrf2 signaling pathway and its crosstalk, and examples of Chinese herbal monomers. It will facilitate pharmacological research and development to promote the utilization of traditional Chinese medicine in DCM.

Integrative pharmacology reveals the mechanisms of Erzhi Pill, a traditional Chinese formulation, against diabetic cardiomyopathy.

ETHNOPHARMACOLOGICAL RELEVANCE: Erzhi Pill (EZP) is a traditional Chinese prescription that has marked effects in treating type 2 diabetes mellitus and diabetic nephropathy. However, its underlying pharmacological mechanisms in the treatment of diabetic cardiomyopathy (DCM), remain to be elucidated. AIM OF THE STUDY: This study aimed to apply an integrative pharmacological strategy to systematically evaluate the pharmacological effects and molecular mechanisms of EZP, and provide a solid theoretical basis for the clinical application of EZP in the treatment of DCM. MATERIALS AND METHODS: In this study, the potential targets and key pathways of EZP were predicted and validated using network pharmacology and molecular docking, respectively. Changes in cardiac metabolites and major metabolic pathways in rat heart samples were examined using 1H-nuclear magnetic resonance (NMR) metabolomics. Finally, biochemical analysis was conducted to detect the protein expression levels of key pathways. RESULTS: We found that EZP decreased fasting blood glucose (FBG), triglycerides (TG), total cholesterol (TC), and low-density lipoprotein (LDL) levels, increased high-density lipoprotein (HDL) levels in the serum, and alleviated the morphological abnormalities of the heart tissue in diabetic rats. Furthermore, EZP effectively restored superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), caspase-3, caspase-8, and caspase-9 activity levels, as well as the levels of reactive oxygen species (ROS), malondialdehyde (MDA), B-cell lymphoma (Bcl)-2, and Bcl-2-associated X protein (Bax) in the heart tissue. Network pharmacology prediction results indicated that the mechanism of EZP in treating DCM was closely related to apoptosis, oxidative stress, and the HIF-1, PI3K-Akt, and FoxO signaling pathways. In addition, 1H-NMR metabolomics confirmed that EZP primarily regulated both energy metabolism and amino acid metabolism, including the tricarboxylic acid (TCA) cycle, ketone bodies metabolism, glutamine and glutamate metabolism, glycine metabolism, and purine metabolism. Finally, immunohistochemistry results indicated that EZP reduced the expression levels of p-AMPK, p-PI3K, p-Akt, and p-FoxO3a proteins, in the heart tissue of DCM rats. CONCLUSION: The results confirmed that the overall therapeutic effect of EZP in the DCM rat model is exerted via inhibition of oxidative stress and apoptosis, alongside the regulation of energy metabolism and amino acid metabolism, as well as the AMPK and PI3K/Akt/FoxO3a signaling pathways. This study provides an experimental basis for the use of EZP in DCM treatment.

ß-Lapachone, an NQO1 activator, alleviates diabetic cardiomyopathy by regulating antioxidant ability and mitochondrial function.

BACKGROUND: Diabetic cardiomyopathy (DC) is one of the major lethal complications in patients with diabetes mellitus (DM); however, no specific strategy for preventing or treating DC has been identified. PURPOSE: This study aimed to investigate the effects of ß-lapachone (Lap), a natural compound that increases antioxidant activity in various tissues, on DC and explore the underlying mechanisms. STUDY DESIGN AND METHODS: As an in vivo model, C57BL/6 mice were fed with the high-fat diet (HF) for 10 weeks to induce type 2 DM. Mice were fed Lap with the HF or after 5 weeks of HF treatment to investigate the protective effects of Lap against DC. RESULTS: In the two in vivo models, Lap decreased heart weight, increased heart function, reduced oxidative stress, and elevated mitochondrial content under the HF. In the in vitro model, palmitic acid (PA) was used to mimic the effects of an HF on the differentiated-cardiomyoblast cell line H9c2. The results demonstrated that Lap reduced PA-induced ROS production by increasing the expression of antioxidant regulators and enzymes, inhibiting inflammation, increasing mitochondrial activity, and thus reducing cell damage. Via the use of specific inhibitors and siRNA, the protective effects of Lap were determined to be mediated mainly by NQO1, Sirt1 and mitochondrial activity. CONCLUSION: Heart damage in DM is usually caused by excessive oxidative stress. This study showed that Lap can protect the heart from DC by upregulating antioxidant ability and mitochondrial activity in cardiomyocytes. Lap has the potential to serve as a novel therapeutic agent for both the prevention and treatment of DC.

14,15-EET involved in the development of diabetic cardiac hypertrophy mediated by PPARs.

Cardiac hypertrophy is a key structural change in diabetic cardiomyopathy, which mechanism is unknown. 14,15-Epoxyeicosatrienoic acid (14,15-EET) generated from arachidonic acid by CYP2J2 has beneficial effects in metabolic syndrome, which also plays vital roles in inflammatory response. Peroxisome proliferator activated receptors (PPARs) are members of the nuclear receptor superfamily and have three subtypes of α, ß (or δ) and γ. Studies have found that 14,15-EET can perform various biological functions by activating PPARs, but its role in diabetic cardiac hypertrophy is unknown. This study aimed to investigate the role of 14,15-EET-PPARs signaling pathway in the development of diabetic cardiac hypertrophy. Diabetic cardiac hypertrophy was developed by high-fat diet feeding combined with streptozotocin (40 mg/kg/d for 5 days, i.p.) in mice and was induced by glucose at 25.5 mmol/L (high glucose, HG) in H9c2 cells. The decreased level of 14,15-EET and the down-regulated expression of PPARα, PPARß and PPARγ were found following diabetic cardiac hypertrophy in mice. Similarly, both the level of 14,15-EET and the PPARs expression were also reduced in HG-induced hypertrophic cardiomyocytes. Supplementation with 14,15-EET improved the cardiomyocyte hypertrophy and up-regulated PPARs expression, which were nullified by 14,15-EEZE, a 14,15-EET antagonist. Taken together, we conclude that the decreased 14,15-EET is involved in the development of diabetic cardiac hypertrophy through the down-regulation of PPARs.

6-Gingerol Alleviates Ferroptosis and Inflammation of Diabetic Cardiomyopathy via the Nrf2/HO-1 Pathway.

Background: Diabetes mellitus (DM) can induce cardiomyocyte injury and lead to diabetic cardiomyopathy (DCM) which presently has no specific treatments and consequently increase risk of mortality. Objective: To characterize the therapeutic effect of 6-gingerol (6-G) on DCM and identify its potential mechanism. Methods: In vivo streptozotocin- (STZ-) induced DM model was established by using a high-fat diet and STZ, followed by low-dose (25 mg/kg) and high-dose (75 mg/kg) 6-G intervention. For an in vitro DCM model, H9c2 rat cardiomyoblast cells were stimulated with high glucose (glucose = 33 mM) and palmitic acid (100 µM) and then treated with 6-G (100 µM). Histological and echocardiographic analyses were used to assess the effect of 6-G on cardiac structure and function in DCM. Western blotting, ELISA, and real-time qPCR were used to assess the expression of ferroptosis, inflammation, and the Nrf2/HO-1 pathway-related proteins and RNAs. Protein expression of collagen I and collagen III was assessed by immunohistochemistry, and kits were used to assay SOD, MDA, and iron levels. Results: The results showed that 6-G decreased cardiac injury in both mouse and cell models of DCM. The cardiomyocyte hypertrophy and interstitial fibrosis were attenuated by 6-G treatment in vivo and resulted in an improved heart function. 6-G inhibited the expression of ferroptosis-related protein FACL4 and the content of iron and enhanced the expression of anti-ferroptosis-related protein GPX4. In addition, 6-G also diminished the secretion of inflammatory cytokines, including IL-1ß, IL-6, and TNF-α. 6-G treatment activated the Nrf2/HO-1 pathway, enhanced antioxidative stress capacity proved by increased activity of SOD, and decreased MDA production. Compared with in vivo, 6-G treatment of H9c2 cells treated with high glucose and palmitic acid could produce a similar effect. Conclusion: These findings suggest that 6-G could protect against DCM by the mechanism of ferroptosis inhibition and inflammation reduction via enhancing the Nrf2/HO-1 pathway.

Potential Mechanisms of Triptolide against Diabetic Cardiomyopathy Based on Network Pharmacology Analysis and Molecular Docking.

The incidence of heart failure was significantly increased in patients with diabetic cardiomyopathy (DCM). The therapeutic effect of triptolide on DCM has been reported, but the underlying mechanisms remain to be elucidated. This study is aimed at investigating the potential targets of triptolide as a therapeutic strategy for DCM using a network pharmacology approach. Triptolide and its targets were identified by the Traditional Chinese Medicine Systems Pharmacology database. DCM-associated protein targets were identified using the comparative toxicogenomics database and the GeneCards database. The networks of triptolide-target genes and DCM-associated target genes were created by Cytoscape. The common targets and enriched pathways were identified by the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. The gene-gene interaction network was analyzed by the GeneMANIA database. The drug-target-pathway network was constructed by Cytoscape. Six candidate protein targets were identified in both triptolide target network and DCM-associated network: STAT3, VEGFA, FOS, TNF, TP53, and TGFB1. The gene-gene interaction based on the targets of triptolide in DCM revealed the interaction of these targets. Additionally, five key targets that were linked to more than three genes were determined as crucial genes. The GO analysis identified 10 biological processes, 2 cellular components, and 10 molecular functions. The KEGG analysis identified 10 signaling pathways. The docking analysis showed that triptolide fits in the binding pockets of all six candidate targets. In conclusion, the present study explored the potential targets and signaling pathways of triptolide as a treatment for DCM. These results illustrate the mechanism of action of triptolide as an anti-DCM agent and contribute to a better understanding of triptolide as a transcriptional regulator of cytokine mRNA expression.

Medium & long-chain acylcarnitine's relation to lipid metabolism as potential predictors for diabetic cardiomyopathy: a metabolomic study.

BACKGROUND: Acylcarnitine is an intermediate product of fatty acid oxidation. It is reported to be closely associated with the occurrence of diabetic cardiomyopathy (DCM). However, the mechanism of acylcarnitine affecting myocardial disorders is yet to be explored. This current research explores the different chain lengths of acylcarnitines as biomarkers for the early diagnosis of DCM and the mechanism of acylcarnitines for the development of DCM in-vitro. METHODS: In a retrospective non-interventional study, 50 simple type 2 diabetes mellitus patients and 50 DCM patients were recruited. Plasma samples from both groups were analyzed by high throughput metabolomics and cluster heat map using mass spectrometry. Principal component analysis was used to compare the changes occurring in the studied 25 acylcarnitines. Multivariable binary logistic regression was used to analyze the odds ratio of each group for factors and the 95% confidence interval in DCM. Myristoylcarnitine (C14) exogenous intervention was given to H9c2 cells to verify the expression of lipid metabolism-related protein, inflammation-related protein expression, apoptosis-related protein expression, and cardiomyocyte hypertrophy and fibrosis-related protein expression. RESULTS: Factor 1 (C14, lauroylcarnitine, tetradecanoyldiacylcarnitine, 3-hydroxyl-tetradecanoylcarnitine, arachidic carnitine, octadecanoylcarnitine, 3-hydroxypalmitoleylcarnitine) and factor 4 (octanoylcarnitine, hexanoylcarnitine, decanoylcarnitine) were positively correlated with the risk of DCM. Exogenous C14 supplementation to cardiomyocytes led to increased lipid deposition in cardiomyocytes along with the obstacles in adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) signaling pathways and affecting fatty acid oxidation. This further caused myocardial lipotoxicity, ultimately leading to cardiomyocyte hypertrophy, fibrotic remodeling, and increased apoptosis. However, this effect was mitigated by the AMPK agonist acadesine. CONCLUSIONS: The increased plasma levels in medium and long-chain acylcarnitine extracted from factors 1 and 4 are closely related to the risk of DCM, indicating that these factors can be an important tool for DCM risk assessment. C14 supplementation associated lipid accumulation by inhibiting the AMPK/ACC/CPT1 signaling pathway, aggravated myocardial lipotoxicity, increased apoptosis apart from cardiomyocyte hypertrophy and fibrosis were alleviated by the acadesine.

Wogonin and Alleviation of Hyperglycemia via Inhibition of DAG Mediated PKC Expression. A Brief Insight.

Protein kinase C (PKC) is a family of protein kinase enzymes that can phosphorylate other proteins and influence their functions, such as signal transduction, cell survival, and death. Increased diacylglycerol (DAG) concentrations, which are typically observed raised in hyperglycemic situations such as diabetes mellitus, can also activate PKC enzymes (DM). On the other hand, PKC isomers have been shown to play an essential role in diabetes and many hyperglycemic complications, most importantly atherosclerosis and diabetic cardiomyopathy (DCM). As a result, blocking PKC activation via DAG can prevent hyperglycemia and related consequences, such as DCM. Wogonin is a herbal medicine which has anti-inflammatory properties, and investigations show that it scavenge oxidative radicals, attenuate nuclear factor-kappa B (NF-κB) activity, inhibit several essential cell cycle regulatory genes, block nitric oxide (NO) and suppress cyclooxygenase- 2 (COX-2). Furthermore, several investigations show that wogonin also attenuates diacylglycerol DAG levels in diabetic mice. Since the DAG-PKC pathway is linked with hyperglycemia and its complications, Wogonin-mediated DAG-PKC attenuation can help treat hyperglycemia and its complications.

Cola nitida infusion modulates cardiometabolic activities linked to cardiomyopathy in diabetic rats.

This study investigated the therapeutic mechanism of Cola nitida seeds on diabetic cardiomyopathy in hearts of diabetic rats. Type 2 diabetic (T2D) rats were treated with C. nitida infusion at 150 or 300 mg/kg body weight (bw). The rats were sacrificed after 6 weeks of treatment, and their hearts harvested. There was an upsurge in oxidative stress on induction of T2D as depicted by the depleted levels of glutathione, superoxide dismutase and catalase activities, and elevated malondialdehyde level. The activities of acetylcholinesterase, and ATPase were significantly elevated, with suppressed ENTPDase and 5'nucleotodase activities in hearts of T2D rats depicting cholinergic and purinergic dysfunctions. Induction of T2D further led to elevated activity of ACE and altered myocardial morphology. Treatment with C. nitida infusion led to reversal of these biomarkers' activities and levels, while maintaining an intact morphology. The infusion caused decreased lipase activity and depletion of diabetes-generated cardiac lipid metabolites, while concomitantly generating saturated and unsaturated fatty acids, fatty esters and alcohols. There was also an inactivation of plasmalogen synthesis and mitochondrial beta-oxidation of long chain saturated fatty acids pathways in T2D rats treated with C. nitida infusion. These results indicate the therapeutic effect of C. nitida infusion against diabetic cardiomyopathy.