scholarly journals Electrocardiographic and Histopathological Characterizations of Diabetic Cardiomyopathy in Rats

2021 ◽  
Author(s):  
Mahmoud E. Youssef ◽  
Mona F. El-Azab ◽  
Marwa A. Abdel-Dayem ◽  
Galal Yahya Metwally ◽  
Ibtesam S. Alanazi ◽  
...  
Keyword(s):  
Diabetic Cardiomyopathy ◽  
Plasma Levels ◽  
Cardiac Fibrosis ◽  
Troponin T ◽  
Diabetic Rats ◽  
P Wave ◽  
Ventricular Rate ◽  
Clinical Disorder ◽  
Collagen Formation ◽  
St Segment

Abstract Diabetes is a clinical condition that is associated with insulin deficiency and hyperglycemia. Cardiomyopathy, retinopathy, neuropathy, and nephropathy are well known complications of the elevated blood glucose. Diabetic cardiomyopathy is a clinical disorder that is associated with systolic and diastolic dysfunction along with cardiac fibrosis, inflammation, and elevated oxidative stress. In this study, diabetes was induced by intraperitoneal injection of streptozotocin (STZ) 50 mg/kg. We determined the plasma levels of cardiac troponin-T (cTnT), and creatinine kinase MB (CK-MB) by ELISA. Diabetic rats showed abnormal cardiac architecture and increased collagen production. significant elevation in ST-segment, prolonged QRS and QT-intervals, and increased ventricular rate were detected. Additionally, diabetic rats showed a prolongation in P wave duration and atrial tachyarrhythmia was observed. Plasma levels of cTnT and CK-MB were elevated. In conclusion, these electrocardiographic changes (elevated ST-segment, prolonged QT interval, and QRS complex, and increased heart rate) along with histopathological changes and increased collagen formation could be markers for the development of diabetic cardiomyopathy in rats.

Protective effects of BiP inducer X (BIX) against diabetic cardiomyopathy in rats

2020 ◽  
Author(s):  
Gholamreza Idari ◽  
Pouran Karimi ◽  
Samad Ghaffari ◽  
Seyed Isaac Hashemy ◽  
Baratali Mashkani
Keyword(s):  
Er Stress ◽  
Diabetic Cardiomyopathy ◽  
Cell Apoptosis ◽  
Cardiac Fibrosis ◽  
Tissue Expression ◽  
Myocardial Cell ◽  
Diabetic Rats ◽  
Mrna Levels ◽  
Protective Effects ◽  
Cardiac Cell

Diabetic cardiomyopathy (DC) is associated with impaired endoplasmic reticulum (ER) function, development of ER stress, and induction of cardiac cell apoptosis. Preventive effects of BiP inducer X (BIX) were investigated against DC characteristic changes in a type 2 diabetes rat model. To establish diabetes, a high-fat diet and a single dose of streptozotocin were administered. Then, animals were assigned into following groups: control, BIX, diabetic animals monitored for one, two, and three weeks. Diabetic rats treated with BIX for one, two, and three weeks. Expressions of various ER stress and apoptotic markers were assessed by immunoblotting method. CHOP gene expression was assessed by Real-time PCR. Tissue expression of BiP was evaluated by immunohistochemistry method. Hematoxylin and eosin and Masson's trichrome staining were performed to assess histological changes in the left ventricle. Cardiac cell apoptosis was examined using TUNEL assay. BIX administration suppressed the activation of the ER stress markers and cleavage of pro-caspase 3 in the diabetic rats. Likewise, tissue expression of BiP protein was increased, while CHOP mRNA levels were decreased. These results were accompanied by reducing cardiac fibrosis and myocardial cell apoptosis suggesting protective effects of BIX against the development of DC by decreasing cardiomyocyte apoptosis and fibrosis.

Mangiferin mitigates diabetic cardiomyopathy in streptozotocin-diabetic rats

2013 ◽  
Vol 91 (9) ◽  
pp. 759-763 ◽  
Author(s):  
Jun Hou ◽  
Dezhi Zheng ◽  
Guocheng Zhong ◽  
Yonghe Hu
Keyword(s):  
Cardiac Function ◽  
Diabetic Cardiomyopathy ◽  
Cardiac Fibrosis ◽  
Diabetic Rats ◽  
Left Ventricular ◽  
Matrix Metalloproteinase 2 ◽  
Severe Left Ventricular Dysfunction ◽  
Streptozotocin Diabetic Rats ◽  
Histopathologic Analysis ◽  
Myocardial Collagen

The purpose of this study was to investigate the cardioprotective effect of mangiferin on diabetic cardiomyopathy (DCM). The DCM model was induced by a high-fat diet and a low dose of streptozotocin. We evaluated the characteristics of DCM by serial echocardiography, electron microscopy, histopathologic analysis of cardiomyocyte fibrosis area, and Western blot analysis of matrix metalloproteinase-2 (MMP-2) and MMP-9 expression. Rats with DCM showed severe left ventricular dysfunction and cardiac fibrosis. Mangiferin mitigated DCM and prevented the accumulation of myocardial collagen. These anatomic findings were accompanied by significant improvements in cardiac function. Based on these results, we conclude that mangiferin has a therapeutic effect on DCM and improves cardiac function.

scholarly journals Exogenous Hydrogen Sulfide Alleviated Left Ventricular Fibrosis Via Enhancing Cardiac Autophagy and Decreasing Cardiomyocyte Apoptosis in StreptozotocinInduced Diabetic Rats: From Network Pharmacology to Experimental Pharmacology

2020 ◽  
pp. 1-8
Author(s):  
Shumin Liu ◽  
Cheng Fang ◽  
Feixue Dong ◽  
Liangyou Zhao ◽  
Yongwu Liu ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Diabetic Cardiomyopathy ◽  
Cardiac Fibrosis ◽  
Diabetic Rats ◽  
Left Ventricular ◽  
Expression Level ◽  
Network Pharmacology ◽  
Control Group ◽  
Associated Proteins

Streptozotocin (STZ)-induced diabetes mellitus (DM) model shows the signal of cardiac dysfunction, which is manifested as myocardial fibrosis and hypertrophy. This study was designed to predict targets of sodium hydrosulfide (NaHS) for diabetic cardiomyopathy and its corresponding triggered pathways by network pharmacology analysis and test the effects of NaHS as well as its mechanism as possible modulators of left ventricular remodeling in diabetic rats. The drug-target networks were constructed via approaches of network pharmacology, and the predicted targets and pathways were validated by in vivo experiments. Rats were randomly divided into 3 groups (n=6/group): STZ-induced DM group (STZDM); STZ-induced DM treated with H2S group (STZ-NaHS); control group. The control group was treated with daily saline (i.p.); the diabetic model was induced by intraperitoneal (i.p.) injections of 40 mg/kg/day STZ. After 12 weeks, the rat cardiac function was determined, and the pathological morphology of the heart was analysed by Masson trichrome staining in each group. The expression level of matrix metalloproteinase 9 (AGEs), CSE, CBS and several autophagy associated proteins were detected by the ELISA analysis. Results from the PPI network implied that 27 targets were key regulators. The AGE-RAGE signaling pathway in diabetic complications and the apoptotic signaling pathway was discovered to be the key to anti-diabetic cardiomyopathy of NaHS upon the GO enrichment analyses and KEGG pathway. In the in vivo experiment, compared with the control group, cardiac fibrosis and attenuated left ventricular function were observed. Furthermore, compared with the control group, the expression level of CSE, CBS and autophagy associated proteins Atg5 was significantly decreased, while that of AGEs, autophagy associated proteins p62 and p-ERK1/2 was significantly increased in the STZDM group (P<0.05). In the STZ-NaHS group, cardiac fibrosis and ventricular dysfunction were ameliorated, the expression level of CSE, CBS and autophagy associated proteins Atg5 was increased, and the expression level of AGEs, autophagy associated proteins p62 and p-ERK1/2 was significantly decreased (P<0.05). In conclusion, H2S may alleviate cardiac fibrosis of the STZ-induced DM rat model by enhancing cardiac autophagy, inhibiting cardiomyocyte apoptosis and downregulating p-ERK1/2.

scholarly journals SERCA2a stimulation by istaroxime improves intracellular Ca2+ handling and diastolic dysfunction in a model of diabetic cardiomyopathy

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
E Torre ◽  
M Arici ◽  
AM Lodrini ◽  
M Ferrandi ◽  
P Barassi ◽  
...  
Keyword(s):  
Diastolic Dysfunction ◽  
Diabetic Cardiomyopathy ◽  
Therapeutic Approach ◽  
Cardiac Fibrosis ◽  
Diabetic Rats ◽  
Left Ventricular ◽  
Intact Cells ◽  
Funding Sources ◽  
Promising Therapeutic Approach

Abstract Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): This work was supported by CVie Therapeutics Limited (Taipei, Taiwan) and Windtree Therapeutics (Warrington, USA) Diabetic cardiomyopathy is a multifactorial disease characterized by an early onset of diastolic dysfunction (DD) that precedes the development of systolic impairment. Mechanisms that can restore cardiac relaxation improving intracellular Ca2+ dynamics represent a promising therapeutic approach for cardiovascular diseases associated to DD. Istaroxime has the double property to accelerate Ca2+ uptake into sarcoplasmic reticulum (SR) through the SR Ca2+ pump (SERCA2a) stimulation and to inhibit Na+/K+ ATPase (NKA). The project aims to characterize istaroxime effects at a concentration (100 nM) marginally affecting NKA, in order to highlight its effects dependent on the stimulation of SERCA2a in a model of mild diabetes. Streptozotocin (STZ) treated diabetic rats were studied at 9 weeks after STZ injection in comparison to controls (CTR). Istaroxime effects were evaluated in vivo and in left ventricular (LV) preparations. STZ animals showed 1) marked DD not associated to cardiac fibrosis, 2) LV mass reduction associated to reduced LV cell dimension and T-tubules loss, 3) reduced LV SERCA2 protein level and activity and 4) slower SR Ca2+ uptake rate, 5) LV action potential (AP) prolongation and increased short-term variability (STV) of AP duration, 6) increased diastolic Ca2+, 7) unaltered SR Ca2+ content and stability in intact cells. Acute istaroxime infusion (0.11 mg/kg/min for 15 min) reduced DD in STZ rats. Accordingly, in STZ myocytes istaroxime (100 nM) stimulated SERCA2a activity and blunted STZ-induced abnormalities in LV Ca2+ dynamics. In CTR myocytes, istaroxime increased diastolic Ca2+ level due to NKA blockade albeit minimal, while its effects on SERCA2a were almost absent. SERCA2a stimulation by istaroxime improved STZ-induced DD and intracellular Ca2+ handling anomalies. Thus, SERCA2a stimulation can be considered a promising therapeutic approach for DD treatment. Abstract Figure.

scholarly journals SERCA2a stimulation by istaroxime improves intracellular Ca2+ handling and diastolic dysfunction in a model of diabetic cardiomyopathy

2021 ◽  
Author(s):  
Eleonora Torre ◽  
Martina Arici ◽  
Alessandra Maria Lodrini ◽  
Mara Ferrandi ◽  
Paolo Barassi ◽  
...  
Keyword(s):  
Diastolic Dysfunction ◽  
Diabetic Cardiomyopathy ◽  
Therapeutic Approach ◽  
Cardiac Fibrosis ◽  
Diabetic Rats ◽  
Left Ventricular ◽  
Intact Cells ◽  
Promising Therapeutic Approach ◽  
Mild Diabetes

Abstract Aims  Diabetic cardiomyopathy is a multifactorial disease characterized by an early onset of diastolic dysfunction (DD) that precedes the development of systolic impairment. Mechanisms that can restore cardiac relaxation improving intracellular Ca2+ dynamics represent a promising therapeutic approach for cardiovascular diseases associated to DD. Istaroxime has the dual properties to accelerate Ca2+ uptake into sarcoplasmic reticulum (SR) through the SR Ca2+ pump (SERCA2a) stimulation and to inhibit Na+/K+ ATPase (NKA). This project aims to characterize istaroxime effects at a concentration (100 nmol/L) marginally affecting NKA, in order to highlight its effects dependent on the stimulation of SERCA2a in an animal model of mild diabetes. Methods and results  Streptozotocin (STZ) treated diabetic rats were studied at 9  weeks after STZ injection in comparison to controls (CTR). Istaroxime effects were evaluated in vivo and in left ventricular (LV) preparations. STZ animals showed (i) marked DD not associated to cardiac fibrosis, (ii) LV mass reduction associated to reduced LV cell dimension and T-tubules loss, (iii) reduced LV SERCA2 protein level and activity and (iv) slower SR Ca2+ uptake rate, (v) LV action potential (AP) prolongation and increased short-term variability (STV) of AP duration, (vi) increased diastolic Ca2+, and (vii) unaltered SR Ca2+ content and stability in intact cells. Acute istaroxime infusion (0.11 mg/kg/min for 15 min) reduced DD in STZ rats. Accordingly, in STZ myocytes istaroxime (100 nmol/L) stimulated SERCA2a activity and blunted STZ-induced abnormalities in LV Ca2+ dynamics. In CTR myocytes, istaroxime increased diastolic Ca2+ level due to NKA blockade albeit minimal, while its effects on SERCA2a were almost absent. Conclusions  SERCA2a stimulation by istaroxime improved STZ-induced DD and intracellular Ca2+ handling anomalies. Thus, SERCA2a stimulation can be considered a promising therapeutic approach for DD treatment.

scholarly journals Empagliflozin and Liraglutide Differentially Modulate Cardiac Metabolism in Diabetic Cardiomyopathy in Rats

2021 ◽  
Vol 22 (3) ◽  
pp. 1177
Author(s):  
Nguyen Ngoc Trang ◽  
Cheng-Chih Chung ◽  
Ting-Wei Lee ◽  
Wan-Li Cheng ◽  
Yu-Hsun Kao ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Diabetic Cardiomyopathy ◽  
Cardiac Fibrosis ◽  
Glucose Transporter ◽  
Protein Kinase B ◽  
Myocardial Dysfunction ◽  
Combined Treatment ◽  
Adenosine Monophosphate ◽  
Diabetic Rats ◽  
Peroxisome Proliferator

Glucagon-like peptide 1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT2is) are antihyperglycemic agents with cardioprotective properties against diabetic cardiomyopathy (DCM). However, the distinctive mechanisms underlying GLP-1RAs and SGLT2is in DCM are not fully elucidated. The purpose of this study was to investigate the impacts of GLP1RAs and/or SGLT2is on myocardial energy metabolism, cardiac function, and apoptosis signaling in DCM. Biochemistry and echocardiograms were studied before and after treatment with empagliflozin (10 mg/kg/day, oral gavage), and/or liraglutide (200 μg/kg every 12 h, subcutaneously) for 4 weeks in male Wistar rats with streptozotocin (65 mg/kg intraperitoneally)-induced diabetes. Cardiac fibrosis, apoptosis, and protein expression of metabolic and inflammatory signaling molecules were evaluated by histopathology and Western blotting in ventricular cardiomyocytes of different groups. Empagliflozin and liraglutide normalized myocardial dysfunction in diabetic rats. Upregulation of phosphorylated-acetyl coenzyme A carboxylase, carnitine palmitoyltransferase 1β, cluster of differentiation 36, and peroxisome proliferator-activated receptor-gamma coactivator, and downregulation of glucose transporter 4, the ratio of phosphorylated adenosine monophosphate-activated protein kinase α2 to adenosine monophosphate-activated protein kinase α2, and the ratio of phosphorylated protein kinase B to protein kinase B in diabetic cardiomyocytes were restored by treatment with empagliflozin or liraglutide. Nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing 3, interleukin-1β, tumor necrosis factor-α, and cleaved caspase-1 were significantly downregulated in empagliflozin-treated and liraglutide-treated diabetic rats. Both empagliflozin-treated and liraglutide-treated diabetic rats exhibited attenuated myocardial fibrosis and apoptosis. Empagliflozin modulated fatty acid and glucose metabolism, while liraglutide regulated inflammation and apoptosis in DCM. The better effects of combined treatment with GLP-1RAs and SGLT2is may lead to a potential strategy targeting DCM.

miR-30a-5p inhibits the proliferation and collagen formation of cardiac fibroblasts in diabetic cardiomyopathy

2022 ◽  
pp. 1-9
Author(s):  
Xiao-xu Yang ◽  
Zhen-yu Zhao
Keyword(s):  
Diabetic Cardiomyopathy ◽  
Cardiac Fibrosis ◽  
Cardiac Tissue ◽  
Cardiac Fibroblasts ◽  
Underlying Mechanism ◽  
Luciferase Reporter ◽  
Luciferase Reporter Gene ◽  
Collagen Formation ◽  
Gene Assay

Cardiac fibrosis is one of the major pathological characteristics of diabetic cardiomyopathy (DCM). MicroRNAs (miRNAs, miRs) have been identified as key regulators in the progression of cardiac fibrosis. This study aimed to investigate the role of miR-30a-5p in DCM and the underlying mechanism. The rat model of diabetes mellitus (DM) was established by streptozotocin injection, and the rat primary cardiac fibroblasts (CFs) were isolated from cardiac tissue and then treated with high glucose (HG). MTT assay was performed to assess the viability of CFs. Dual-luciferase reporter gene assay was conducted to verify the interaction between miR-30a-5p and Smad2. The expression of miR-30a-5p was downregulated in the myocardial tissues of DM rats and HG-stimulated CFs. Overexpression of miR-30a-5p reduced Smad2 levels and inhibited collagen formation in HG-stimulated CFs and DM rats, as well as decreased the proliferation of CFs induced by HG. Smad2 was a target of miR-30a-5p and its expression was inhibited by miR-30a-5p. Furthermore, the simultaneous overexpression of Smad2 and miR-30a-5p reversed the effect of miR-30a-5p overexpression alone in CFs. Our results indicated that miR-30a-5p reduced Smad2 expression and also induced a decrease in proliferation and collagen formation in DCM.

Exercise and Stevia Rebaudiana (R) Extracts Attenuate Diabetic Cardiomyopathy in Type 2 Diabetic Rats: Possible Underlying Mechanisms

2020 ◽  
Vol 20 (7) ◽  
pp. 1117-1132
Author(s):  
Abdelaziz M. Hussein ◽  
Elsayed A. Eid ◽  
Ismaeel Bin-Jaliah ◽  
Medhat Taha ◽  
Lashin S. Lashin
Keyword(s):  
Oxidative Stress ◽  
Blood Glucose ◽  
Diabetic Cardiomyopathy ◽  
Caspase 3 ◽  
Stevia Rebaudiana ◽  
Diabetic Rats ◽  
Control Group ◽  
Underlying Mechanisms ◽  
Type 2 Diabetic

Background and Aims: In the current work, we studied the effects of exercise and stevia rebaudiana (R) extracts on diabetic cardiomyopathy (DCM) in type 2 diabetic rats and their possible underlying mechanisms. Methods: : Thirty-two male Sprague Dawley rats were randomly allocated into 4 equal groups; a) normal control group, b) DM group, type 2 diabetic rats received 2 ml oral saline daily for 4 weeks, c) DM+ Exercise, type 2 diabetic rats were treated with exercise for 4 weeks and d) DM+ stevia R extracts: type 2 diabetic rats received methanolic stevia R extracts. By the end of the experiment, serum blood glucose, HOMA-IR, insulin and cardiac enzymes (LDH, CK-MB), cardiac histopathology, oxidative stress markers (MDA, GSH and CAT), myocardial fibrosis by Masson trichrome, the expression of p53, caspase-3, α-SMA and tyrosine hydroxylase (TH) by immunostaining in myocardial tissues were measured. Results: T2DM caused a significant increase in blood glucose, HOMA-IR index, serum CK-MB and LDH, myocardial damage and fibrosis, myocardial MDA, myocardial α-SMA, p53, caspase-3, Nrf2 and TH density with a significant decrease in serum insulin and myocardial GSH and CAT (p< 0.05). On the other hand, treatment with either exercise or stevia R extracts significantly improved all studied parameters (p< 0.05). Moreover, the effects of stevia R was more significant than exercise (p< 0.05). Conclusion: Both exercise and methanolic stevia R extracts showed cardioprotective effects against DCM and Stevia R offered more cardioprotective than exercise. This cardioprotective effect of these lines of treatment might be due to attenuation of oxidative stress, apoptosis, sympathetic nerve density and fibrosis and upregulation of the antioxidant transcription factor, Nrf2.

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