scholarly journals Endogenous asymmetric dimethylarginine accumulation contributes to the suppression of myocardial mitochondrial biogenesis in type 2 diabetic rats

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Yan Xiong ◽  
Chun-Xia Hai ◽  
Wei-Jin Fang ◽  
Yan-Ping Lei ◽  
Xiao-Mei Li ◽  
...  
Keyword(s):  
Mitochondrial Biogenesis ◽  
Promoter Activity ◽  
Asymmetric Dimethylarginine ◽  
Diabetic Rats ◽  
Luciferase Reporter ◽  
Protein Acetylation ◽  
Rat Cardiomyocytes ◽  
Mitochondrial Biosynthesis ◽  
Type 2 Diabetic

Abstract Background Suppressed mitochondrial biosynthesis has been reported to be the early signal of mitochondrial dysfunction which contributes to diabetic cardiomyopathy, but the mechanism of mitochondrial biosynthesis suppression is unclear. Nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA) is closely related to diabetic cardiovascular complications. This study was to determine whether endogenous ADMA accumulation was involved in the suppression of myocardial mitochondrial biogenesis in diabetic rats and to elucidate the potential mechanism in rat cardiomyocytes. Methods Type 2 diabetic rat model was induced by high-fat feeding plus single intraperitoneal injection of small dose streptozotocin (35 mg/kg). The copy number ratio of mitochondrial gene to nuclear gene was measured to reflect mitochondrial biogenesis. The promoter activity of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) and its post-translational modifications were detected by dual-luciferase reporter assay and immunoprecipitation. Results Myocardial ADMA content was enhanced and associated with suppressions of myocardial mitochondrial biogenesis and cardiac function in parallel with PGC-1α downregulation and uncoupling protein 2 (UCP2) upregulation in the myocardium of diabetic rats compared with control rats. Similarly, ADMA and its homolog could inhibit myocardial mitochondrial biogenesis and PGC-1α expression, increase UCP2 expression and oxidative stress in vitro and in vivo. Moreover, ADMA also suppressed the promoter activity and PGC-1α expression but boosting its protein acetylation and phosphorylation in rat cardiomyocytes. Conclusions These results indicate that endogenous ADMA accumulation contributes to suppression of myocardial mitochondrial biogenesis in type 2 diabetic rats. The underlying mechanisms may be associated with reducing PGC-1α promoter activity and expression but boosting its protein acetylation and phosphorylation.

Study on the Effect of Cerium Oxide Nanocubes on Full-Thickness Cutaneous Wound Healing of Type 2 Diabetic Rats

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 643-P ◽  
Author(s):  
YANFEI HAN ◽  
LINDONG LI ◽  
YANJUN LIU ◽  
YOU WANG ◽  
CHUNHUA YAN ◽  
...  
Keyword(s):  
Wound Healing ◽  
Cerium Oxide ◽  
Diabetic Rats ◽  
Cutaneous Wound Healing ◽  
Full Thickness ◽  
Cutaneous Wound ◽  
Type 2 Diabetic

Neuroprotection of Maslinic Acid, a Novel Glycogen Phos-phorylase Inhibitor, in Type 2 Diabetic Rats

2010 ◽  
Vol 8 (4) ◽  
pp. 293-297 ◽  
Author(s):  
Teng GUAN ◽  
Yi-Song QIAN ◽  
Meng-Hao HUANG ◽  
Long-Fei HUANG ◽  
Xu-Zhen TANG ◽  
...  
Keyword(s):  
Diabetic Rats ◽  
Maslinic Acid ◽  
Type 2 Diabetic

Blockade of Renin Angiotensin System Ameliorates the Cardiac Arrhythmias and Sympathetic Neural Remodeling in Hearts of Type 2 DM Rat Model

2020 ◽  
Vol 20 (3) ◽  
pp. 464-478 ◽  
Author(s):  
Yomna M. Yehya ◽  
Abdelaziz M. Hussein ◽  
Khaled Ezam ◽  
Elsayed A. Eid ◽  
Eman M. Ibrahim ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Cardiac Arrhythmias ◽  
Sympathetic Nerve ◽  
Renin Angiotensin System ◽  
Diabetic Rats ◽  
Angiotensin System ◽  
Type 2 Dm ◽  
Type 2 Diabetic ◽  
Diabetes Induction

Objectives:: The present study was designed to investigate the effects of renin angiotensin system (RAS) blockade on cardiac arrhythmias and sympathetic nerve remodelling in heart tissues of type 2 diabetic rats. Methods:: Thirty-two male Sprague Dawley rats were randomly allocated into 4 equal groups; a) normal control group: normal rats, b) DM group; after type 2 diabetes induction, rats received 2ml oral saline daily for 4 weeks, c) DM+ ACEi: after type 2 diabetes induction, rats were treated with enalapril (10 mg/kg, orally for 4 weeks) and d) DM+ ARBs: after type 2 diabetes induction, rats were treated with losartan (30 mg/kg, orally for 4 weeks). Results:: In type 2 diabetic rats, the results demonstrated significant prolongation in Q-T interval and elevation of blood sugar, HOMA-IR index, TC, TGs, LDL, serum CK-MB, myocardial damage, myocardial MDA, myocardial norepinephrine and tyrosine hydroxylase (TH) density with significant reduction in serum HDL, serum insulin and myocardial GSH and CAT. On the other hand, blockade of RAS at the level of either ACE by enalapril or angiotensin (Ag) receptors by losartan resulted in significant improvement in ECG parameters (Q-T), cardiac enzymes (CK-MB), cardiac morphology, myocardial oxidative stress (low MDA, high CAT and GSH) and myocardial TH density. Conclusions:: RAS plays a role in the cardiac sympathetic nerve sprouting and cardiac arrhythmias induced by type 2 DM and its blockade might have a cardioprotective effect via attenuation of sympathetic nerve fibres remodelling, myocardial norepinephrine contents and oxidative stress.

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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