scholarly journals GDF11 alleviates pathological myocardial remodeling in diabetic cardiomyopathy through SIRT1-dependent regulation of oxidative stress and apoptosis

Author(s):  
Hanzhao Zhu ◽  
Liyun Zhang ◽  
Mengen Zhai ◽  
Lin Xia ◽  
Yu Cao ◽  
...  

Abstract Background Diabetic cardiomyopathy (DCM) is characterized by cardiac dysfunction and cardiomyocyte injury, which induced by metabolic disorder. Nowadays, there is still a lack of drugs for the treatment of DCM. Growth differentiation factor 11 (GDF11) is a novel member of the transforming growth factor β superfamily that alleviates cardiac hypertrophy, myocardial infarction, and vascular injury by regulating oxidative stress, inflammation, and cell survival. However, the roles and underlying mechanisms of GDF11 in DCM remain largely unknown. Methods In this study, we sought to determine whether GDF11 could prevent DCM. The mouse model of diabetes was established by administering a high-fat diet and intraperitoneal injecting streptozotocin. After that, intramyocardial injection of an adeno-associated virus carrying GDF11 gene was used to achieve myocardium-specific overexpression. Results Our data showed that GDF11 overexpression remarkably improved cardiac dysfunction and interstitial fibrosis by reducing the levels of reactive oxygen species and protecting against cardiomyocyte loss. Mechanistically, decreased sirtuin 1 (SIRT1) expression was observed in diabetic mice, which was significantly increased after GDF11 overexpression. To further explore how SIRT1 mediates the role of GDF11, the selective inhibitor EX527 was used to block SIRT1 signaling pathway, which abolished the protective effects of GDF11 against DCM. In vitro studies confirmed that GDF11 protected against H9c2 cell injury in high glucose and palmitate by attenuating oxidative injury and apoptosis, and these effects were also eliminated by SIRT1 depletion. Conclusion Our results demonstrated for the first time that GDF11 protected against DCM by regulating SIRT1 signaling pathway, and GDF11 had the potential to become a novel target for reversing cardiac dysfunction in diabetic patients.

Author(s):  
Han-Zhao Zhu ◽  
Li-Yun Zhang ◽  
Meng-En Zhai ◽  
Lin Xia ◽  
Yu Cao ◽  
...  

Growth differentiation factor 11 (GDF11) is a member of the transforming growth factor β superfamily that alleviates cardiac hypertrophy, myocardial infarction, and vascular injury by regulating oxidative stress, inflammation, and cell survival. However, the roles and underlying mechanisms of GDF11 in diabetic cardiomyopathy (DCM) remain largely unknown. In this study, we sought to determine whether GDF11 could prevent DCM. After establishing a mouse model of diabetes by administering a high-fat diet and streptozotocin, intramyocardial injection of an adeno-associated virus was used to achieve myocardium-specific GDF11 overexpression. GDF11 remarkably improved cardiac dysfunction and interstitial fibrosis by reducing the levels of reactive oxygen species and protecting against cardiomyocyte loss. Mechanistically, decreased sirtuin 1 (SIRT1) expression and activity were observed in diabetic mice, which was significantly increased after GDF11 overexpression. To further explore how SIRT1 mediates the role of GDF11, the selective inhibitor EX527 was used to block SIRT1 signaling pathway, which abolished the protective effects of GDF11 against DCM. In vitro studies confirmed that GDF11 protected against H9c2 cell injury in high glucose and palmitate by attenuating oxidative injury and apoptosis, and these effects were eliminated by SIRT1 depletion. Our results demonstrate for the first time that GDF11 protects against DCM by regulating SIRT1 signaling pathway.


2020 ◽  
Author(s):  
Jinxin Wang ◽  
Jing Bai ◽  
Peng Duan ◽  
Hao Wang ◽  
Yang Li ◽  
...  

Abstract Background: Diabetic cardiomyopathy (DCM) severely impairs the health of diabetic patients. Previous studies have shown that the expression of inwardly rectifying potassium channel 6.1 (Kir6.1) in heart mitochondria is significantly reduced in type 1 diabetes. However, whether its expression and function are changed and what role it plays in type 2 DCM have not been reported. This study investigated the role and mechanism of Kir6.1 in DCM.Methods: The cardiac function in mice was analyzed by echocardiography, ELISA, hematoxylin and eosin staining, TUNEL and transmission electron microscopy. The mitochondrial function in cardiomyocytes was measured by the oxygen consumption rate and the mitochondrial membrane potential (ΔΨm). Kir6.1 expression at the mRNA and protein levels was analyzed by quantitative real-time PCR and western blotting (WB), respectively. The protein expression of t-AKT, p-AKT, t-Foxo1, and p-Foxo1 was analyzed by WB.Results: We found that the cardiac function and the Kir6.1 expression in DCM mice were decreased. Kir6.1 overexpression improved cardiac dysfunction and upregulated the phosphorylation of AKT and Foxo1 in the DCM mouse model. Furthermore, Kir6.1 overexpression also improved cardiomyocyte dysfunction and upregulated the phosphorylation of AKT and Foxo1 in cardiomyocytes with insulin resistance. In contrast, cardiac-specific Kir6.1 knockout aggravated the cardiac dysfunction and downregulated the phosphorylation of AKT and Foxo1 in DCM mice. Furthermore, Foxo1 activation downregulated the expression of Kir6.1 and decreased the ΔΨm in cardiomyocytes. In contrast, Foxo1 inactivation upregulated the expression of Kir6.1 and increased the ΔΨm in cardiomyocytes. Chromatin immunoprecipitation assay demonstrated that the Kir6.1 promoter region contains a functional Foxo1-binding site .Conclusions: Kir6.1 improves cardiac dysfunction in DCM, probably through the AKT-Foxo1 signaling pathway. Moreover, the crosstalk between Kir6.1 and the AKT-Foxo1 signaling pathway may provide new strategies for reversing the defective signaling in DCM.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Ioannis D Kyriazis ◽  
Matthew K Hoffman ◽  
Lea Gaignebet ◽  
Anna Maria Lucchese ◽  
Chao Wang ◽  
...  

Introduction: Cardiomyopathy in type 1 diabetes (T1D) is accompanied by impaired mitochondrial function, oxidative stress and lipotoxicity. We showed that cardiomyocyte (CM) Krüppel-like factor 5 (KLF5) is increased in streptozotocin-induced T1D and induces Peroxisome Proliferator Activated Receptor (PPAR)α in mice. Hypothesis: KLF5 upregulation by FOXO1 induces diabetic cardiomyopathy (DbCM). Methods and Results: Analyses in CM from diabetic patients showed higher KLF5 mRNA levels compared to non-diabetic individuals. In vitro mechanistic and in vivo analyses in αMHC- Foxo1 -/- mice revealed that FOXO1 stimulates KLF5 expression via direct promoter binding. Genetic inhibition of CM FOXO1 alleviated DbCM. Additionally, AAV-mediated CM-specific KLF5 overexpression in C57Bl/6 (WT) mice induced cardiac dysfunction. Mice with CM-specific KLF5 constitutive expression (αMHC-rtTA- Klf5 ), which we generated, recapitulated cardiomyopathy without T1D. Moreover, Pparα -/- mice with T1D, had higher CM-KLF5 levels and developed DbCM, suggesting that KLF5-driven DbCM is PPARα-independent. Additionally, CM-KLF5 induced oxidative stress through increased NADPH oxidase (NOX)4 expression and lower mitochondria abundance. Conversely, KLF5 inhibition prevented NOX4 upregulation and superoxide formation. Furthermore, CM-KLF5 promoted NOX4 expression via direct promoter binding. Antioxidant treatment in diabetic WT and αMHC-rtTA- Klf5 mice alleviated cardiac dysfunction partially, suggesting other pathways that contribute in KLF5-induced DbCM. For that, we performed cardiac lipidome analysis where we found clustering of αMHC-rtTA- Klf5 with diabetic WT mice. Of note, KLF5 inhibition in diabetic mice resulted in similar lipidome with non-diabetic WT mice. Individual lipid species analysis showed increased ceramide accumulation in diabetic WT and αMHC-rtTA- Klf5 mice that was reversed upon KLF5 inhibition. Thus, CM-KLF5 activation correlates with cardiac ceramide accumulation, that has been associated with cardiac lipotoxicity. Conclusions: In conclusion, T1D stimulates FOXO1, which induces CM-KLF5 expression that leads to oxidative stress and DbCM in a non-PPARα-dependent manner, as well as to cardiac ceramide accumulation.


2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Suresh K Verma ◽  
Alexander R Mackie ◽  
Erin E Vaughan ◽  
Tatiana V Abramova ◽  
Raj kishore ◽  
...  

Patients with diabetes are predisposed to increased risk of cardiovascular diseases. Persistent interaction of infiltrating macrophages and resident fibroblasts play a critical role in cardiac fibrosis. However, the signaling mechanism is not clear. We hypothesized that macrophage ELAV1 (mRNA stabilizing protein) modulates profibrotic mediators and extracellular matrix turnover by binding to 3′UTR and regulating the mRNA stability of TGF-beta and MMP-9 in hyperglycemic conditions. Mice receiving intramyocardial injection of HuR-specific shRNA showed significant reduction in infarct size and fibrosis area. Reduced fibrosis was associated with decrease in TGF-beta and MMP-9 expression in the myocardium. Conditioned media (CM) from high glucose (HG) treated macrophages significantly increased profibrogenic response (increased mRNA expression of Col1a1, Col3a1 and fibronectin) in fibroblast cell line as compared to fibroblasts incubated with CM from low glucose (LG)-treated macrophages. Knockdown of ELAV1 in HG-treated macrophages abrogated the profibrotic effects in fibroblasts. Indirect immunofluroscence of bone marrow-derived macrophages (BMM) demonstrated that HG increases nuclear ELAV1 export to the cytoplasm. Pharmacological inhibition of Protein kinase C-delta (PKCd) blocked HG-induced ELAV1 nuclear to cytoplasmic translocation. In vitro, stable knockdown of ELAV1 in mouse macrophage cell line RAW 264.7 reduced mRNA expression of TGF-beta and MMP-9 following LPS challenge, accompanied by a marked reduction in the mRNA stability of these genes. Our study here establishes an ELAV1/TGF-beta/MMP-9/PKC-delta signaling axis in the macrophages controlling the profibrogenic responses in fibroblasts, the major contributor in the pathogenesis of fibrosis. Therefore, targeting this signaling pathway might be of therapy value for cardiac fibrosis in diabetic patients.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Kaifeng Li ◽  
Mengen Zhai ◽  
Liqing Jiang ◽  
Fan Song ◽  
Bin Zhang ◽  
...  

Hyperglycemia-induced oxidative stress and fibrosis play a crucial role in the development of diabetic cardiomyopathy (DCM). Tetrahydrocurcumin (THC), a major bioactive metabolite of natural antioxidant curcumin, is reported to exert even more effective antioxidative and superior antifibrotic properties as well as anti-inflammatory and antidiabetic abilities. This study was designed to investigate the potential protective effects of THC on experimental DCM and its underlying mechanisms, pointing to the role of high glucose-induced oxidative stress and interrelated fibrosis. In STZ-induced diabetic mice, oral administration of THC (120 mg/kg/d) for 12 weeks significantly improved the cardiac function and ameliorated myocardial fibrosis and cardiac hypertrophy, accompanied by reduced reactive oxygen species (ROS) generation. Mechanically, THC administration remarkably increased the expression of the SIRT1 signaling pathway both in vitro and in vivo, further evidenced by decreased downstream molecule Ac-SOD2 and enhanced deacetylated production SOD2, which finally strengthened antioxidative stress capacity proven by repaired activities of SOD and GSH-Px and reduced MDA production. Additionally, THC treatment accomplished its antifibrotic effect by depressing the ROS-induced TGFβ1/Smad3 signaling pathway followed by reduced expression of cardiac fibrotic markers α-SMA, collagen I, and collagen III. Collectively, these finds demonstrated the therapeutic potential of THC treatment to alleviate DCM mainly by attenuating hyperglycemia-induced oxidative stress and fibrosis via activating the SIRT1 pathway.


2016 ◽  
Vol 68 (16) ◽  
pp. C40-C41
Author(s):  
Gan Shouyi ◽  
Hui Yu ◽  
Hong-xia Huang ◽  
Bing Li ◽  
Ling-Yong Zeng ◽  
...  

Diabetologia ◽  
2017 ◽  
Vol 60 (6) ◽  
pp. 1126-1137 ◽  
Author(s):  
Zhen-Guo Ma ◽  
Yu-Pei Yuan ◽  
Si-Chi Xu ◽  
Wen-Ying Wei ◽  
Chun-Ru Xu ◽  
...  

2021 ◽  
Vol 8 ◽  
Author(s):  
Ya-nan Mo ◽  
Feng Cheng ◽  
Zhen Yang ◽  
Xiao-fei Shang ◽  
Jian-ping Liang ◽  
...  

The fruits of Ailanthus altissima Swingle (AS) possess a variety of pharmacological activities. Its antioxidant activity and the potential mode of action have not yet been investigated. In in vitro studies, AS revealed the strong reducing power and DPPH scavenging effect, but hydroxyl radical scavenging activity and ferrous ions-chelating ability were not strong. Meanwhile, the oxidative stress RAW264.7 cell injury model was established, the low and medium-doses of AS showed significant protective effects on the viability of H2O2-treated cells by CCK-8 method. Besides, three doses of AS all increased the activities of SOD, CAT, and GSH-Px and decreased the MDA level compared with the H2O2 group, suggesting it significantly relieved oxidative stress of cells. The active ingredients and related targets of AS were collected by HERB and Swiss Target Prediction database, the common targets of drugs and diseases database were conducted by GeneCards database platform and the Venny platform. We screened the core targets of AS like threonine kinase1 (AKT1), mitogen-activated protein kinase 1 (MAPK1), sirtuin-1 (SIRT1), mechanistic target of rapamycin kinase (MTOR) by STRING database, and the key pathways involved PI3K-AKT and FoxO signaling pathway by KEGG pathway enrichment analysis. Besides, qRT-PCR revealed AS preconditioning significantly up-regulated the expression level of AKT1, SIRT1, MAPK1, and MTOR in model cells, and the effect was related to the regulation of FoxO and PI3K/AKT signaling pathway. In summary, AS showed significant antioxidant activity and its potential mechanism was regulating FoxO and PI3K/AKT signaling pathway.


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