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

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.

Author(s):  
Shumin Liu ◽  
Cheng Fang ◽  
Feixue Dong ◽  
Liangyou Zhao ◽  
Yongwu Liu ◽  
...  

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.


EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
E Torre ◽  
M Arici ◽  
AM Lodrini ◽  
M Ferrandi ◽  
P Barassi ◽  
...  

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.


2021 ◽  
Author(s):  
Eleonora Torre ◽  
Martina Arici ◽  
Alessandra Maria Lodrini ◽  
Mara Ferrandi ◽  
Paolo Barassi ◽  
...  

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.


2019 ◽  
Vol 21 (7) ◽  
pp. 862-873 ◽  
Author(s):  
Salva R. Yurista ◽  
Herman H.W. Silljé ◽  
Silke U. Oberdorf‐Maass ◽  
Elisabeth‐Maria Schouten ◽  
Mario G. Pavez Giani ◽  
...  

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Zejuan Sheng ◽  
Xiaoyan Qiang ◽  
Guoyu Li ◽  
Huimin Wang ◽  
Wenxin Dong ◽  
...  

Introduction: Phosphodiesterase 9 (PDE9) controls natriuretic-peptide-stimulated cyclic guanosine monophosphate in cardiac myocytes and is stongly upregulated in human heart failure, suggesting its potential as a promising therapeutic target in heart failure. Here we investigated the potential effects of TT-00920, a clinical stage novel and highly selective PDE9 inhibitor, on heart failure in a rat model of myocardial infarction. Methods: Myocardial infarction was induced by left anterior descending coronary artery (LAD) ligation in male Sprague Dawley rats. After 4-week treatment of vehicle, LCZ696, TT-00920, or TT-00920/Valsartan by oral gavage, efficacy was assessed by echocardiography and cardiac histopathology. Results: TT-00920 had remarkably improved cardiac function, protected against cardiac remodeling and fibrosis in a dose-dependent manner. TT-00920/Valsartan combination showed superior beneficial efficacy when compared to TT-00920 or LCZ696 single agent.Figure 1. TT-00920 improved cardiac function and ventricular remodeling.Figure 2. TT-00920 attenuated cardiac fibrosis in peri-infarct zone. Conclusions: TT-00920 reversed LAD-induced left ventricular dysfunction and remodeling, supporting its potential as a novel therapeutic agent for heart failure. The superior efficacy of TT-00920/Valsartan combination suggests that TT-00920 and renin-angiotensin-aldosterone system inhibitors may have additive therapeutic effects in heart failure.TT-00920 is currently being evaluated in Phase 1 clinical study for safety, tolerability, pharmacokinetics and pharmacodynamics in healthy volunteers (NCT04364789).


2009 ◽  
Vol 37 (06) ◽  
pp. 1059-1068 ◽  
Author(s):  
Min Ge ◽  
Shanfeng Ma ◽  
Liang Tao ◽  
Sudong Guan

The relationship between changes of cardiac function and the gene expressions of two major myocardial skeleton proteins, titin and nebulin, and the effect of gypenosides on these gene expressions in diabetic cardiomyopathy rat were explored in the present study. Forty Sprague-Dawley rats were randomly divided into three groups: control group, diabetic cardiomyopathy group and gypenosides-treated diabetic cardiomyopathy group. The diabetic cardiomyopathy was induced in rats by injecting streptozotocin (STZ, 55 mg/kg) intraperitoneally. Seven weeks after the rats suffered from diabetes, the rats were treated with gypenosides 100 mg/kg per day orally for six weeks in gypenosides-treated group. In the meanwhile, the pure water was given to diabetic cardiomyopathy and the control groups. Subsequently, the cardiac functions, including left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP), ± dP/dtmax and t–dP/dmaxt, as well as the mRNA content and proteins of titin and nebulin in myocardium were determined. The results indicated that (1) the diabetic cardiomyopathy rats had decreased LVSP and ± dP/dtmax, increased LVEDP, and prolonged t–dP/dtmax than normal rats; (2) LVSP and ± dP/dtmax in diabetic cardiomyopathy rats treated with gypenosides were significantly higher and LVEDP and t–dP/dtmax were significantly lower than those without giving gypenosides; (3) the mRNA contents and proteins of titin and nebulin in diabetic cardiomyopathy rats were remarkably lower than those in the control rats and gypenosides had no effect on mRNA and protein expression levels of titin and nebulin in diabetic cardiomyopathy rats. We conclude that (1) the cardiac function as well as the mRNA expressions of titin and nebulin decreased in diabetic cardiomyopathy rats; (2) gypenosides secure cardiac muscles and their function from diabetic impairment and these beneficial effects of gypenosides are not by changing the expressions of titin and nebulin.


1993 ◽  
Vol 71 (3-4) ◽  
pp. 270-276 ◽  
Author(s):  
Violet G. Yuen ◽  
Chris Orvig ◽  
Katherine H. Thompson ◽  
John H. McNeill

Decreased cardiac function in streptozotocin-diabetic rats has been used as a model of diabetes-induced cardiomyopathy, which is a secondary complication in diabetic patients. The present study was designed to evaluate the therapeutic effect of a new organic vanadium complex, bis(maltolato)oxovanadium(IV), (BMOV), in improving heart function in streptozotocin-diabetic rats. There were four groups of male, Wistar rats: control (C), control treated (CT), diabetic (D), and diabetic treated (DT). Treatment consisted of BMOV, 0.5 mg/mL (1.8 mM) for the first 3 weeks and 0.75 mg/mL (2.4 mM) for the next 22 weeks, in the drinking water of rats allowed ad libitum access to food and water. BMOV lowered blood glucose to < 9 mM in 70% of DT animals without any increase in plasma insulin levels, and mean blood glucose and plasma lipid levels were significantly lower in DT vs. D rats. Tissue vanadium levels were measured in plasma, bone, kidney, liver, muscle, and fat of BMOV-treated rats. Plasma vanadium levels averaged 0.84 ± 0.07 μg/mL (16.8 μM) in CT rats and 0.76 ± 0.05 μg/mL (15.2 μM) in DT animals. The highest vanadium levels at termination of this chronic feeding study were in bone, 18.3 ± 3.0 μg/g (0.37 μmol/g) in CT and 26.4 ± 2.6 μg/g (0.53 μmol/g) in DT rats, with intermediate levels in kidney and liver, and low, but detectable levels in muscle and fat. There were no deaths in either the CT or DT group, and no overt signs of vanadium toxicity were present. Tissue vanadium levels were not correlated with the glucose-lowering effect. Isolated working heart parameters of left ventricular developed pressure (LVDP) and rate of pressure development (+dP/dT, and −dP/dT) indicated that BMOV treatment resulted in significant correction of the heart dysfunction associated with streptozotocin-induced diabetes in rat.Key words: bis(maltolato)oxovanadium(IV), vanadium, diabetes, streptozotocin, myocardial dysfunction.


1986 ◽  
Vol 251 (3) ◽  
pp. H571-H580 ◽  
Author(s):  
B. Rodrigues ◽  
J. H. McNeill

The isolated perfused working heart was used to study hypertensive diabetes-induced alterations in cardiac function at 6 and 12 wk after diabetes was induced. At 6 wk after diabetes induction, cardiac performance was depressed in the diabetic animals. However, there was no difference in cardiac function between normotensive Wistar and spontaneously hypertensive (SHR) diabetic rats. Wistar-Kyoto (WKY) rats were also included as normotensive controls in our 12-wk study. Hearts from 12-wk SHR and Wistar diabetic animals exhibited a depressed left ventricular developed pressure and positive and negative dP/dt when compared with control animals. However, this depression was not seen in the WKY diabetic animals. In addition, quantitation of various parameters of heart function revealed highly significant differences between SHR diabetic animals and all other groups associated with an increased mortality. Serum lipids were elevated in SHR and Wistar and were unaffected in WKY diabetic rats. Furthermore, thyroid hormone levels were not depressed in WKY diabetic rats as seen in the other two diabetic groups. This normal lipid metabolism and thyroid status could, in part, explain the lack of cardiac dysfunction in these animals. The data provide further evidence that the combination of hypertension and diabetes mellitus produces greater myocardial dysfunction than with either disease alone and is associated with a significant mortality.


Author(s):  
Gholamreza Idari ◽  
Pouran Karimi ◽  
Samad Ghaffari ◽  
Seyed Isaac Hashemy ◽  
Baratali Mashkani

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.


1999 ◽  
Vol 86 (3) ◽  
pp. 812-818 ◽  
Author(s):  
Kiminori Kato ◽  
Donald C. Chapman ◽  
Heinz Rupp ◽  
Anton Lukas ◽  
Naranjan S. Dhalla

To examine the role of changes in myocardial metabolism in cardiac dysfunction in diabetes mellitus, rats were injected with streptozotocin (65 mg/kg body wt) to induce diabetes and were treated 2 wk later with the carnitine palmitoyltransferase inhibitor (carnitine palmitoyltransferase I) etomoxir (8 mg/kg body wt) for 4 wk. Untreated diabetic rats exhibited a reduction in heart rate, left ventricular systolic pressure, and positive and negative rate of pressure development and an increase in end-diastolic pressure. The sarcolemmal Na+-K+-ATPase activity was depressed and was associated with a decrease in maximal density of binding sites (Bmax) value for high-affinity sites for [3H]ouabain, whereas Bmax for low-affinity sites was unaffected. Treatment of diabetic animals with etomoxir partially reversed the depressed cardiac function with the exception of heart rate. The high serum triglyceride and free fatty acid levels were reduced, whereas the levels of glucose, insulin, and 3,3′,-5-triiodo-l-thyronine were not affected by etomoxir in diabetic animals. The activity of Na+-K+-ATPase expressed per gram heart weight, but not per milligram sarcolemmal protein, was increased by etomoxir in diabetic animals. Furthermore, Bmax (per g heart wt) for both low-affinity and high-affinity binding sites in control and diabetic animals was increased by etomoxir treatment. Etomoxir treatment also increased the depressed left ventricular weight of diabetic rats and appeared to increase the density of the sarcolemma and transverse tubular system to normalize Na+-K+-ATPase activity. Therefore, a shift in myocardial substrate utilization may represent an important signal for improving the depressed cardiac function and Na+-K+-ATPase activity in diabetic rat hearts with impaired glucose utilization.


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