scholarly journals Mitochondrial dynamic modulation exerts cardiometabolic protection in obese insulin-resistant rats

2019 ◽  
Vol 133 (24) ◽  
pp. 2431-2447 ◽  
Author(s):  
Chayodom Maneechote ◽  
Siripong Palee ◽  
Nattayaporn Apaijai ◽  
Sasiwan Kerdphoo ◽  
Thidarat Jaiwongkam ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Cardiac Function ◽  
Mitochondrial Dynamics ◽  
Combined Therapy ◽  
Mitochondrial Fission ◽  
Combined Treatment ◽  
Myocardial Cell ◽  
Normal Diet ◽  
Mitochondrial Dynamic ◽  
Insulin Resistant

Abstract Obese insulin resistance impairs cardiac mitochondrial dynamics by increasing mitochondrial fission and decreasing mitochondrial fusion, leading to mitochondrial damage, myocardial cell death and cardiac dysfunction. Therefore, inhibiting fission and promoting fusion could provide cardioprotection in this pre-diabetic condition. We investigated the combined effects of the mitochondrial fission inhibitor (Mdivi1) and fusion promoter (M1) on cardiac function in obese insulin-resistant rats. We hypothesized that Mdivi1 and M1 protect heart against obese insulin-resistant condition, but also there will be greater improvement using Mdivi1 and M1 as a combined treatment. Wistar rats (n=56, male) were randomly assigned to a high-fat diet (HFD) and normal diet (ND) fed groups. After feeding with either ND or HFD for 12 weeks, rats in each dietary group were divided into groups to receive either the vehicle, Mdivi1 (1.2 mg/kg, i.p.), M1 (2 mg/kg, i.p.) or combined treatment for 14 days. The cardiac function, cardiac mitochondrial function, metabolic and biochemical parameters were monitored before and after the treatment. HFD rats developed obese insulin resistance which led to impaired dynamics balance and function of mitochondria, increased cardiac cell apoptosis and dysfunction. Although Mdivi1, M1 and combined treatment exerted similar cardiometabolic benefits in HFD rats, the combined therapy showed a greater reduction in mitochondrial reactive oxygen species (ROS). Mitochondrial fission inhibitor and fusion promoter exerted similar levels of cardioprotection in a pre-diabetic condition.

Abstract P049: Circadian Clock Dysfunction Impairs Mitochondrial Fitness And Contributes To Myocardial Ischemic Injury

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Inna Rabinovich-Nikitin ◽  
Illana Posen ◽  
Victoria Margulets ◽  
Tami A Martino ◽  
Lorrie A Kirshenbaum
Keyword(s):  
Quality Control ◽  
Cell Viability ◽  
Circadian Clock ◽  
Cardiac Myocytes ◽  
Mitochondrial Dynamics ◽  
Ischemia Reperfusion ◽  
Mitochondrial Fission ◽  
Control Mechanisms ◽  
Complex Activity ◽  
Mitochondrial Dynamic

Cardiac function is highly reliant on mitochondrial oxidative metabolism and fitness. The circadian clock is critically linked to vital physiological process including mitochondrial fission, fusion and quality control mechanisms. However, little is known of how the circadian clock regulates these vital processes in the heart. Herein, we identified a putative circadian Clock - mitochondrial interactome that gates an adaptive stress response for cell viability during myocardial ischemia reperfusion (I-R) injury. We show that Clock transcriptionally coordinates expression of mitochondrial dynamic fusion and fission, bioenergetic and quality control proteins in cardiac myocytes. Transcriptome and gene ontology mapping revealed Clock defective hearts subjected to I-R exhibited major transcriptional deficits in several key survival processes including mitochondrial dynamics, bioenergetics and autophagy that were reduced further following I-R. Gain of function of Clock activity re-established gene transcription of mitochondrial respiratory complex activity, quality control mechanisms and cell viability. Collectively, our data show that mitochondrial fitness and cell survival is mutually dependent upon and obligatorily linked to transcription of the circadian Clock gene in cardiac myocytes. Our data suggest the functional loss of Clock activity predisposes cardiac myocytes to metabolic catastrophe. Hence, therapeutic strategies designed to preserve circadian clock activity in the hearts may prove beneficial in reducing morbidity and mortality following ischemia -related pathologies such as myocardial infarction.

scholarly journals T-2 Toxin-Induced Oxidative Stress Leads to Imbalance of Mitochondrial Fission and Fusion to Activate Cellular Apoptosis in the Human Liver 7702 Cell Line

Toxins ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 43 ◽  
Author(s):  
Junhua Yang ◽  
Wenbo Guo ◽  
Jianhua Wang ◽  
Xianli Yang ◽  
Zhiqi Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Apoptosis ◽  
Human Liver ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Fission ◽  
Mitochondrial Fusion ◽  
Mitochondrial Dynamic ◽  
Normal Human Liver ◽  
Induced Apoptosis

T-2 toxin, as a highly toxic mycotoxin to humans and animals, induces oxidative stress and apoptosis in various cells and tissues. Apoptosis and mitochondrial fusion/fission are two tightly interconnected processes that are crucial for maintaining physiological homeostasis. However, the role of mitochondrial fusion/fission in apoptosis of T-2 toxin remains unknown. Hence, we aimed to explore the putative role of mitochondrial fusion/fission on T-2 toxin induced apoptosis in normal human liver (HL-7702) cells. T-2 toxin treatment (0, 0.1, 1.0, or 10 μg/L) for 24 h caused decreased cell viability and ATP concentration and increased production of (ROS), as seen by a loss of mitochondrial membrane potential (∆Ψm) and increase in mitochondrial fragmentation. Subsequently, the mitochondrial dynamic imbalance was activated, evidenced by a dose-dependent decrease and increase in the protein expression of mitochondrial fusion (OPA1, Mfn1, and Mfn2) and fission (Drp1 and Fis1), respectively. Furthermore, the T-2 toxin promoted the release of cytochrome c from mitochondria to cytoplasm and induced cell apoptosis triggered by upregulation of Bax and Bax/Bcl-2 ratios, and further activated the caspase pathways. Taken together, these results indicate that altered mitochondrial dynamics induced by oxidative stress with T-2 toxin exposure likely contribute to mitochondrial injury and HL-7702 cell apoptosis.

scholarly journals Prebiotic prevents impaired kidney and renal Oat3 functions in obese rats

2018 ◽  
Vol 237 (1) ◽  
pp. 29-42 ◽  
Author(s):  
Keerati Wanchai ◽  
Sakawdaurn Yasom ◽  
Wannipa Tunapong ◽  
Titikorn Chunchai ◽  
Parameth Thiennimitr ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Renal Function ◽  
High Fat Diet ◽  
Organic Anion ◽  
Normal Diet ◽  
Organic Anion Transporter ◽  
High Fat ◽  
Insulin Resistant ◽  
Beneficial Effects ◽  
Anion Transporter

Obesity is health issue worldwide, which can lead to kidney dysfunction. Prebiotics are non-digestible foods that have beneficial effects on health. This study aimed to investigate the effects of xylooligosaccharide (XOS) on renal function, renal organic anion transporter 3 (Oat3) and the mechanisms involved. High-fat diet was provided for 12 weeks in male Wistar rats. After that, the rats were divided into normal diet (ND); normal diet treated with XOS (NDX); high-fat diet (HF) and high-fat diet treated with XOS (HFX). XOS was given daily at a dose of 1000 mg for 12 weeks. At week 24, HF rats showed a significant increase in obesity and insulin resistance associated with podocyte injury, increased microalbuminuria, decreased creatinine clearance and impaired Oat3 function. These alterations were improved by XOS supplementation. Renal MDA level and the expression of AT1R, NOX4, p67phox, 4-HNE, phosphorylated PKCα and ERK1/2 were significantly decreased after XOS treatment. In addition, Nrf2-Keap1 pathway, SOD2 and GCLC expression as well as renal apoptosis were also significantly reduced by XOS. These data suggest that XOS could indirectly restore renal function and Oat3 function via the reduction of oxidative stress and apoptosis through the modulating of AT1R-PKCα-NOXs activation in obese insulin-resistant rats. These attenuations were instigated by the improvement of obesity, hyperlipidemia and insulin resistance.

Balancing mitochondrial dynamics via increasing mitochondrial fusion attenuates infarct size and left ventricular dysfunction in rats with cardiac ischemia/reperfusion injury

2019 ◽  
Vol 133 (3) ◽  
pp. 497-513 ◽  
Author(s):  
Chayodom Maneechote ◽  
Siripong Palee ◽  
Sasiwan Kerdphoo ◽  
Thidarat Jaiwongkam ◽  
Siriporn C. Chattipakorn ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Infarct Size ◽  
Cardiac Dysfunction ◽  
Ischemia Reperfusion Injury ◽  
Mitochondrial Dynamics ◽  
Ischemia Reperfusion ◽  
Mitochondrial Fission ◽  
Left Ventricular ◽  
Mitochondrial Fusion ◽  
Time Points

Abstract An uncontrolled balance of mitochondrial dynamics has been shown to contribute to cardiac dysfunction during ischemia/reperfusion (I/R) injury. Although inhibition of mitochondrial fission could ameliorate cardiac dysfunction, modulation of mitochondrial fusion by giving a fusion promoter at different time-points during cardiac I/R injury has never been investigated. We hypothesized that giving of a mitochondrial fusion promoter at different time-points exerts cardioprotection with different levels of efficacy in rats with cardiac I/R injury. Forty male Wistar rats were subjected to a 30-min ischemia by coronary occlusion, followed by a 120-min reperfusion. The rats were then randomly divided into control and three treated groups: pre-ischemia, during-ischemia, and onset of reperfusion. A pharmacological mitochondrial fusion promoter-M1 (2 mg/kg) was used for intervention. Reduced mitochondrial fusion protein was observed after cardiac I/R injury. M1 administered prior to ischemia exerted the highest level of cardioprotection by improving both cardiac mitochondrial function and dynamics regulation, attenuating incidence of arrhythmia, reducing infarct size and cardiac apoptosis, which led to the preservation of cardiac function and decreased mortality. M1 given during ischemia and on the onset of reperfusion also exerted cardioprotection, but with a lower efficacy than when given at the pre-ischemia time-point. Attenuating a reduction in mitochondrial fusion proteins during myocardial ischemia and at the onset of reperfusion exerted cardioprotection by attenuating mitochondrial dysfunction and dynamic imbalance, thus reducing infarct size and improving cardiac function. These findings indicate that it could be a promising intervention with the potential to afford cardioprotection in the clinical setting of acute myocardial infarction.

scholarly journals Myoferlin Is a Yet Unknown Interactor of the Mitochondrial Dynamics’ Machinery in Pancreas Cancer Cells

Cancers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1643
Author(s):  
Sandy Anania ◽  
Raphaël Peiffer ◽  
Gilles Rademaker ◽  
Alexandre Hego ◽  
Marc Thiry ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Cell Lines ◽  
Cancer Cell ◽  
Pancreas Cancer ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Fission ◽  
Cancer Cell Lines ◽  
Ductal Adenocarcinoma ◽  
Mitochondrial Dynamic ◽  
Pancreatic Cancer Cells

Pancreas ductal adenocarcinoma is one of the deadliest cancers where surgery remains the main survival factor. Mitochondria were described to be involved in tumor aggressiveness in several cancer types including pancreas cancer. We have previously reported that myoferlin controls mitochondrial structure and function, and demonstrated that myoferlin depletion disturbs the mitochondrial dynamics culminating in a mitochondrial fission. In order to unravel the mechanism underlying this observation, we explored the myoferlin localization in pancreatic cancer cells and showed a colocalization with the mitochondrial dynamic machinery element: mitofusin. This colocalization was confirmed in several pancreas cancer cell lines and in normal cell lines as well. Moreover, in pancreas cancer cell lines, it appeared that myoferlin interacted with mitofusin. These discoveries open-up new research avenues aiming at modulating mitofusin function in pancreas cancer.

scholarly journals RCAN1.4 mediates high glucose-induced matrix production by stimulating mitochondrial fission in mesangial cells

2020 ◽  
Vol 40 (1) ◽  
Author(s):  
Hong-Min Chen ◽  
Jia-Jia Dai ◽  
Rui Zhu ◽  
Xue-Yu Sang ◽  
Fang-Fang Peng ◽  
...  
Keyword(s):  
High Glucose ◽  
Matrix Protein ◽  
Mesangial Cells ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Fission ◽  
Cell Types ◽  
Glomerular Mesangial Cells ◽  
Mitochondrial Fragmentation ◽  
Mitochondrial Dynamic ◽  
Matrix Production

Abstract High glucose (HG)-induced mitochondrial dynamic changes and oxidative damage are closely related to the development and progression of diabetic kidney disease (DKD). Recent studies suggest that regulators of calcineurin 1 (RCAN1) is involved in the regulation of mitochondrial function in different cell types, so we investigate the role of RCAN1 in mitochondrial dynamics under HG ambience in rat glomerular mesangial cells (MCs). MCs subjected to HG exhibited an isoform-specific up-regulation of RCAN1.4 at both mRNA and protein levels. RCAN1.4 overexpression induced translocation of Dynamin related protein 1 (Drp1) to mitochondria, mitochondrial fragmentation and depolarization, accompanied by increased matrix production under normal glucose and HG ambience. In contrast, decreasing the expression of RCAN1.4 by siRNA inhibited HG-induced mitochondrial fragmentation and matrix protein up-regulation. Moreover, both mitochondrial fission inhibitor Mdivi-1 and Drp1 shRNA prevented RCAN1.4-induced fibronectin up-regulation, suggesting that RCAN1.4-induced matrix production is dependent on its modulation of mitochondrial fission. Although HG-induced RCAN1.4 up-regulation was achieved by activating calcineurin, RCAN1.4-mediated mitochondrial fragmentation and matrix production is independent of calcineurin activity. These results provide the first evidence for the HG-induced RCAN1.4 up-regulation involving increased mitochondrial fragmentation, leading to matrix protein up-regulation.

scholarly journals Novel Insights into the Molecular Features and Regulatory Mechanisms of Mitochondrial Dynamic Disorder in the Pathogenesis of Cardiovascular Disease

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Ying Tan ◽  
Fengfan Xia ◽  
Lulan Li ◽  
Xiaojie Peng ◽  
Wenqian Liu ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Mitochondrial Dynamics ◽  
Ischemia Reperfusion ◽  
Mitochondrial Fission ◽  
Regulatory Mechanisms ◽  
Septic Cardiomyopathy ◽  
Mitochondrial Dynamic ◽  
Dynamic Disorder ◽  
Molecular Features ◽  
And Function

Mitochondria maintain mitochondrial homeostasis through continuous fusion and fission, that is, mitochondrial dynamics, which is precisely mediated by mitochondrial fission and fusion proteins, including dynamin-related protein 1 (Drp1), mitofusin 1 and 2 (Mfn1/2), and optic atrophy 1 (OPA1). When the mitochondrial fission and fusion of cardiomyocytes are out of balance, they will cause their own morphology and function disorders, which damage the structure and function of the heart, are involved in the occurrence and progression of cardiovascular disease such as ischemia-reperfusion injury (IRI), septic cardiomyopathy, and diabetic cardiomyopathy. In this paper, we focus on the latest findings regarding the molecular features and regulatory mechanisms of mitochondrial dynamic disorder in cardiovascular pathologies. Finally, we will address how these findings can be applied to improve the treatment of cardiovascular disease.

Abstract 20707: Macrophage Mitochondrial Fission is Essential for Continued Clearance of Apoptotic Cells and Plays a Protective Role in Advanced Atherosclerosis

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Ying Wang ◽  
Ira Tabas ◽  
Masatoshi Nomura
Keyword(s):  
Mitochondrial Dynamics ◽  
Uncoupling Protein ◽  
Mitochondrial Fission ◽  
Myeloid Cell ◽  
Protective Role ◽  
Mitochondrial Fusion ◽  
Apoptotic Cells ◽  
Mitochondrial Dynamic ◽  
Inner Membrane

Introduction: The mitochondrial dynamic processes of fission and fusion influence and integrate with multiple physiologic and pathophysiologic processes. Mitochondrial dynamics dysregulation has been implicated in atherosclerosis, but little is known about the role of myeloid cell specific mitochondrial dynamics in the progression of atherosclerosis. In macrophage-enriched murine atherosclerosis lesion areas, we have found that levels of mitochondrial fission protein DRP1 down-regulated as the lesion progresses. In contrast, the mitochondrial fusion protein MFN2 is up-regulated. Further, mitochondria in lesional macrophages show hyperfusion morphology as the lesion develops. These suggest that mitochondria in macrophages undergo hyperfusion during the lesion progression. Hypothesis: We hypothesize that mitochondrial hyperfusion plays a significant role in atherosclerosis. Methods: We used a model Drp1fl/fl LysmCre+/-Ldlr-/-mice who have hyperfused mitochondria in Mϕs to test the functional significance of mitochondrial hyperfusion in atherosclerosis. Results: We have found that inhibition of Mϕ mitochondrial fission leads to a striking increase of necrotic core area and the accumulation of apoptotic cells, which are likely due to the defective phagocytic clearance of apoptotic cells (efferocytosis) in the advanced stage of atherosclerosis in vivo. This is further verified by another in vivo efferocytosis assay: Drp1fl/fl LysmCre+/-mice are defective of clearing apoptotic thymocytes in vivo. Mechanistically, the continued uptake of apoptotic cellsis impaired in Mϕs with hyperfused mitochondria. This is because of the lower level of uncoupling protein 2 (UCP2), the mitochondrial inner membrane protein that prevents the sustained elevation of inner membrane potential (Δψ). Chemical uncoupler FCCP or restoration of UCP2 can correct the efferocytosis deficiency in DRP1 knockout Mϕs. Conclusions: Macrophage mitochondrial fission is essential for continued clearance of apoptotic cells and plays a protective role in advanced atherosclerosis. This study indicates that mitochondrial fusion/fission could be a novel therapeutic target to prevent lesion necrosis and stabilize the advanced plaques in humans.

Abstract 279: Stromal Cell-derived Factor-1 Prevents From Diabetic Cardiomyopathy via Cxcr7/ampk-mediated Nrf2 Activation in Type 2 Diabetic Mice

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Shudong Wang ◽  
Junlian Gu ◽  
Xiaoqing Yan ◽  
Jing Chen ◽  
Jun Chen ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Blood Glucose ◽  
Cardiac Function ◽  
Stromal Cell ◽  
Normal Diet ◽  
Diabetic Mice ◽  
Nrf2 Activation ◽  
Stromal Cell Derived Factor ◽  
Type 2 Diabetic

We have demonstrated that stromal cell-derived factor 1(SDF-1) protects against palmitate-induced cardiac cell death via CXCR7-mediated activation of AMPK signaling (Diabetes 62:2545-2558, 2013). Whether SDF-1 prevents diabetic cardiomyopathy (DCM) and what the underlying mechanism has not been addressed. Here we evaluated the prevention of SDF-1 from DCM in a high fat diet plus streptozotocin (HFD/STZ)-induced type 2 diabetic model in C57BL/6J mice. After 1 month on HFD, the HFD-fed mice were injected with one low dose STZ (100mg/kg body weight, ip). Five days after STZ injection, mice with blood glucose levels ≥250 mg/dl were defined as diabetic. In parallel, the age-matched normal diet-fed mice injected with a same volume of vehicle were used as control. After onset of diabetes, the mice were maintained on HFD or normal diet for another 4 months with or without SDF-1 treatment. Then cardiac function was assayed again, and the mice were sacrificed and cardiac tissue collected for cardiomyopathic index assay. We found that 1 month HFD feeding induced a significant insulin resistance without effect on cardiac function, but continued HFD feeding after STZ injection significantly increased insulin resistance and blood glucose, as well as blood insulin, triglyceride and cholesterol levels. Furthermore, HFD/STZT significantly impaired cardiac function, which were accompanied by increased cardiac inflammation, oxidative stress and fibrotic remodeling. Treatment with SDF-1 dose-dependently prevented diabetes-induced cardiac dysfunction, inflammation and remodeling, but without significant effects on the above mentioned other pathophysiological changes. Mechanistic study demonstrated that diabetes significantly inhibited the function of AMPK and Nrf2, and the expression of CXCR7, but not CXCR4; while treatment with SDF-1 significantly preserved AMPK and Nrf2 function and CXCR7 expression. Knockout CXCR4 did not affect SDF-1 preservation of AMPK and Nrf2 function, but SiRNA knockdown of AMPK resulted in blockade of SDF-1 preservation of Nrf2 function. These results indicate that SDF-1 prevents from DCM via CXCR7/AMPK-mediated Nrf2 activation in type 2 diabetic mice.

Abstract 315: Stromal Cell-derived Factor 1 Protects From Diabetic Cardiomyopathy

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Xiaoqing Yan ◽  
Shudong Wang ◽  
Jing Chen ◽  
Jun Chen ◽  
Jun Zeng ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Blood Glucose ◽  
Cardiac Function ◽  
Diabetic Cardiomyopathy ◽  
Stromal Cell ◽  
Cardiac Tissue ◽  
Normal Diet ◽  
Citrate Buffer ◽  
Glucose Levels ◽  
Stromal Cell Derived Factor

We have demonstrated that stromal cell-derived factor 1(SDF-1) protects against palmitate-induced cardiac apoptosis, which is mediated by NOX-activated nitrosative damage and endoplasmic reticulum stress, via CXCR7, to activate AMPK/p38 MAPK-mediated IL-6 generation (Diabetes 62:2545-2558, 2013). Whether SDF-1 prevents diabetic cardiomyopathy has not been addressed. Here we evaluated the preventive effects of SDF-1 from diabetic cardiomyopathy in a high fat diet plus streptozotocin (HFD/STZ)-induced type 2 diabetic model in C57BL/6J mice. After 1 month on HFD, cardiac function was assayed by echocardiography, and then HFD-fed mice were injected with one low dose STZ (100mg/kg body weight, ip). Five days after STZ injection, mice with blood glucose levels ≥250 mg/dl were defined as diabetic. In parallel, the age-matched normal diet-fed mice injected with a same volume of citrate buffer (pH4.5) were used as control. After onset of diabetes, the mice were maintained on HFD or normal diet for another 4 months with or without SDF-1 treatment. Then cardiac function was assayed again, and the mice were sacrificed and cardiac tissue collected for cardiomyopathic index assay. We found that 1 month HFD feeding induced a significant insulin resistance without effect on cardiac function, but continued HFD feeding after STZ injection significantly impaired cardiac function, which were accompanied by increased insulin resistance and blood glucose, as well as blood insulin, triglyceride and cholesterol levels. Treatment with SDF-1 dose-dependently prevented diabetes-induced cardiac dysfunction but without significant effects on the above mentioned other pathophysiological parameters. These results indicate that SDF-1 possibly prevents diabetic cardiomyopathy via a direct cardiomyocyte action, which needs to be further defined in future study.

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