Abstract P172: Activation of Pgc1α by EET Stimulates Insulin Sensitivity, Normalizes Blood Pressure and Increases Mitochondrial Oxphos in Obese Mice

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Shailendra P Singh ◽  
Maayan Waldman ◽  
Joseph Schragenheim ◽  
Lars Bellner ◽  
Jian Cao ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Insulin Sensitivity ◽  
Mitochondrial Biogenesis ◽  
Mitochondrial Function ◽  
Fasting Blood Glucose ◽  
Cardiovascular Complications ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Glucose Levels ◽  
Obesity In Mice

Background/Objectives: Obesity is a risk factor in the development of type 2 diabetes mellitus (DM2), which is associated with increased morbidity and mortality, predominantly as a result of cardiovascular complications. Increased adiposity is a systemic condition characterized by increased oxidative stress (ROS), inflammation, inhibition of anti-oxidant genes such as HO-1 and increased degradation of epoxyeicosatrienoic acids (EETs). Hypothesis: We postulate that EETs increase peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) activity, which controls mitochondrial function, oxidative metabolism and may also increase antioxidants and HO-1 gene expression. Methods: C57/B16 mice were fed a high fat (HF) diet for 26 wks. The protocol comprised three groups: A) WT, B) HF control and C) HF-treated with EET agonist (EET-A). Renal and visceral fat tissues were harvested to measure signaling protein. Consumption was measured at 6 and 24 wks. Mice were used to assess insulin levels, insulin sensitivity, blood pressure and mitochondrial OXPHOS and mitochondrial biogenesis (Mfn1, 2 and Opa1), and oxygen consumption (VO 2 ). Results: Animals on a HF diet exhibited increased body weight, fat content, fasting blood glucose levels, systolic blood pressure (BP) and a significant reduction in VO 2 . Administration of EET-A to HF-fed mice decreased the RQ (VCO 2 /VO 2 ) ratio and normalized BP. The HF diet produced increased levels of the adipogenic markers MEST, aP2, C/EBPα and FAS. EET-A attenuated these perturbations through an increase in renal and adipose tissue PGC1α levels. The EET-mediated HO-1 induction increased mitochondrial function as measured by OXPHOS, MnSOD and thermogenic genes, TFAM, UCP1 and SIRT 1. EET-A also increased adiponectin levels, and insulin receptor phosphorylation IRP Tyr 972 and 1146 and normalized glucose levels. Conclusion: These data show that an EET agonist increased PGC-1α-HO-1 levels thereby providing metabolic protection and increased VO 2 consumption in HF-induced obesity in mice. This novel finding suggests that the EET-mediated PGC-1α activation is essential to increase HO-1 levels, mitochondrial biogenesis, and to decrease mitochondrial ROS and adiposity.

PGC-1α-mediated regulation of mitochondrial function and physiological implications

2020 ◽  
Vol 45 (9) ◽  
pp. 927-936
Author(s):  
Jens Frey Halling ◽  
Henriette Pilegaard
Keyword(s):  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
Mitochondrial Biogenesis ◽  
Mitochondrial Function ◽  
Current Evidence ◽  
Peroxisome Proliferator ◽  
Control Mechanisms ◽  
Peroxisome Proliferator Activated Receptor ◽  
Age Related ◽  
Mitochondrial Functions

The majority of human energy metabolism occurs in skeletal muscle mitochondria emphasizing the importance of understanding the regulation of myocellular mitochondrial function. The transcriptional co-activator peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) has been characterized as a major factor in the transcriptional control of several mitochondrial components. Thus, PGC-1α is often described as a master regulator of mitochondrial biogenesis as well as a central player in regulating the antioxidant defense. However, accumulating evidence suggests that PGC-1α is also involved in the complex regulation of mitochondrial quality beyond biogenesis, which includes mitochondrial network dynamics and autophagic removal of damaged mitochondria. In addition, mitochondrial reactive oxygen species production has been suggested to regulate skeletal muscle insulin sensitivity, which may also be influenced by PGC-1α. This review aims to highlight the current evidence for PGC-1α-mediated regulation of skeletal muscle mitochondrial function beyond the effects on mitochondrial biogenesis as well as the potential PGC-1α-related impact on insulin-stimulated glucose uptake in skeletal muscle. Novelty PGC-1α regulates mitochondrial biogenesis but also has effects on mitochondrial functions beyond biogenesis. Mitochondrial quality control mechanisms, including fission, fusion, and mitophagy, are regulated by PGC-1α. PGC-1α-mediated regulation of mitochondrial quality may affect age-related mitochondrial dysfunction and insulin sensitivity.

scholarly journals Low-Frequency Electroacupuncture Improves Insulin Sensitivity in Obese Diabetic Mice through Activation of SIRT1/PGC-1αin Skeletal Muscle

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Fengxia Liang ◽  
Rui Chen ◽  
Atsushi Nakagawa ◽  
Makoto Nishizawa ◽  
Shinichi Tsuda ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
Fasting Blood Glucose ◽  
Low Frequency ◽  
Tolerance Test ◽  
Sirtuin 1 ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Obesity And Diabetes

Electroacupuncture (EA) has been observed to reduce insulin resistance in obesity and diabetes. However, the biochemical mechanism underlying this effect remains unclear. This study investigated the effects of low-frequency EA on metabolic action in genetically obese and type 2 diabetic db/db mice. Nine-week-old db/m and db/db mice were randomly divided into four groups, namely, db/m, db/m + EA, db/db, and db/db + EA. db/m + EA and db/db + EA mice received 3-Hz electroacupuncture five times weekly for eight consecutive weeks. In db/db mice, EA tempered the increase in fasting blood glucose, food intake, and body mass and maintained insulin levels. In EA-treated db/db mice, improved insulin sensitivity was established through intraperitoneal insulin tolerance test. EA was likewise observed to decrease free fatty acid levels in db/db mice; it increased protein expression in skeletal muscle Sirtuin 1 (SIRT1) and induced gene expression of peroxisome proliferator-activated receptor coactivator (PGC-), nuclear respiratory factor 1 (NRF1), and acyl-CoA oxidase (ACOX). These results indicated that EA offers a beneficial effect on insulin resistance in obese and diabetic db/db mice, at least partly, via stimulation of SIRT1/PGC-, thus resulting in improved insulin signal.

Abstract 024: PGC-1α is a Critical Activator of HO-1 That Protects Against Cardiomyopathy in Diabetic Mice Through Recruitment of Mitochondrial Fusion Proteins and Function

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Jian Cao ◽  
John A McClung ◽  
Maayan Waldman ◽  
Shailendra P Singh ◽  
Joseph Schragenheim ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Fusion Proteins ◽  
Cardiac Tissue ◽  
Fasting Blood Glucose ◽  
Cardiovascular Complications ◽  
Mitochondrial Fusion ◽  
Heart Weight ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Beneficial Effects

Introduction: Diabetes mellitus type 2 (DM2) is associated with cardiovascular complications, which are characterized by increased oxidative stress (ROS) and inhibition of anti-oxidant genes such as heme oxygenase (HO-1), Super oxide dismutase (SOD2) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). The latter that controls mitochondrial biogenesis, oxidative metabolism, and increased degradation of epoxyeicosatrienoic acids (EETs). Inhibition of these genes leads to increased myocardial stiffness and the development of cardiac hypertrophy and diastolic dysfunction. Aim: To assess whether PGC-1α plays a significant role in the development of diabetic cardiomyopathy in chronically obese mice. Methods: Leptin resistant (db/db) mice develop cardiomyopathy at the age of 5-6 month. Mice were treated with the EET agonist (EET-A) and with either lentivirus (Ln)- PGC-1α (Sh) or EET-A-Ln-PGC-1α scrambled for 3 additional months. Results: db mice exhibited impaired glucose tolerance, increased fasting blood glucose (366±21.9mg/dL vs.112±9.2 mg/dL, p<0.004), decreased oxygen consumption (VO 2 ) (25.09±1.1ml/min vs. 55.37±5.92ml/min, p<0.002) and heart weight (0.17±0.02g vs.0.12±0.006g, p<0.05) compared to WT mice. EET agonists treatments improved fasting glucose levels (366±21.9mg/dL vs. 134±18.4 mg/dL, p<0.007) and oxygen consumption (25.09±1.1ml/min vs. 33.7±3.75ml/min, p<0.018), and reduced heart weight (0.17±0.02g vs.0.13±0.002g, p<0.0026). HO-1 levels were increased in cardiac tissue 22-fold (p<0.016). The beneficial effects of EET were reversed inhibition of PGC-1α in the EET-A-Ln PGC-1α (Sh) not in EET-A-Ln-PGC-1α scrambled group. The inhibition of PGC-1α (52% reduction, p<0.022) resulted in a reduction in the beneficial effects of EET-A as manifested by weight gain, the development of severe dilated cardiomyopathy and the attenuation of HO-1 and SOD2 (90% and 76% reduction respectively, p<0.02) and a decrease in mitochondrial fusion proteins Mfn1, 2 and OPa1. Conclusion: EET mediated restoration of mitochondrial function by PGC1α is essential for the enhancement of HO-1-myocyte contraction and the prevention of LV dysfunction in chronic obesity.

scholarly journals Rhein Reduces Fat Weight indb/dbMouse and Prevents Diet-Induced Obesity in C57Bl/6 Mouse through the Inhibition of PPARγSignaling

PPAR Research ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Yu Zhang ◽  
Shengjie Fan ◽  
Na Hu ◽  
Ming Gu ◽  
Chunxiao Chu ◽  
...  
Keyword(s):  
Target Genes ◽  
Fasting Blood Glucose ◽  
Peroxisome Proliferator ◽  
Brown Adipocytes ◽  
Peroxisome Proliferator Activated Receptor ◽  
Glucose Levels ◽  
Rheum Palmatum ◽  
Diet Induced Obesity ◽  
Blood Glucose Levels ◽  
Underlying Mechanisms

Rheum palmatumhas been used most frequently in the weight-reducing formulae in traditional Chinese medicine. However, the components ofRheum palmatumthat play the antiobesity role are still uncertain. Here, we tested the weight-reducing effect of two majorRheum palmatumcompounds ondb/dbmouse. We found that rhein (100 mg kg−1 day−1), but not emodin, reduced the fat weight indb/dbmouse. Using diet-induced obese (DIO) C57BL/6 mice, we identified that rhein blocked high-fat diet-induced obesity, decreased fat mass and the size of white and brown adipocytes, and lowered serum cholesterol, LDL cholesterol, and fasting blood glucose levels in the mice. To elucidate the underlying mechanisms, we used reporter assay and gene expression analysis and found that rhein inhibited peroxisome proliferator-activated receptorγ(PPARγ) transactivity and the expression of its target genes, suggesting that rhein may act as a PPARγantagonist. Our data indicate that rhein may be a promising choice for antiobesity therapy.

scholarly journals Is the Mitochondrial Function of Keloid Fibroblasts Affected by Cytoglobin?

2021 ◽  
Vol 28 (2) ◽  
pp. 39-47
Author(s):  
Sri Widia A Jusman ◽  
Isma Nur Azzizah ◽  
Mohamad Sadikin ◽  
Novi Silvia Hardiany
Keyword(s):  
Mitochondrial Biogenesis ◽  
Mitochondrial Function ◽  
Ribonucleic Acid ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Messenger Ribonucleic Acid ◽  
Keloid Fibroblast ◽  
Excessive Proliferation ◽  
Keloid Fibroblasts

Background: A keloid is a benign skin tumour characterised by excessive proliferation of fibroblasts, a process that requires a sufficient amount of energy. The energy needs are associated with adequate oxygen (O2) flow and well-functioning mitochondria. It is known that cytoglobin (CYGB) has a function in O2 distribution. The aim of the present study was to explore whether the inhibition of CYGB expression caused impaired mitochondrial function of keloid fibroblasts. Methods: An in vitro study was conducted on a keloid fibroblast derived from our previous study. The study was carried out in the laboratory of the Biochemistry & Molecular Biology Department, Faculty of Medicine, Universitas Indonesia (FMUI), from July to December 2018. CYGB expression was inhibited by small interfering ribonucleic acid (siRNA) and CYGB. Analysis of mitochondrial function was observed through peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), a mitochondrial biogenesis marker and the activity of the succinate dehydrogenase (SDH) enzyme in mitochondria. Results: The CYGB gene and protein were downregulated after treatment with CYGB siRNA. Inhibition of CYGB expression with siRNA also tended to decrease the levels of PGC-1α messenger ribonucleic acid (mRNA) and protein, as well as SDH enzyme activity. Conclusion: Inhibition of CYGB expression with siRNA tended to decrease mitochondrial biogenesis and function. This may be useful for understanding the excessive proliferation of fibroblasts in keloids and for development of treatment for keloids.

scholarly journals A New Insight into an Alternative Therapeutic Approach to Restore Redox Homeostasis and Functional Mitochondria in Neurodegenerative Diseases

Antioxidants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 7
Author(s):  
Dong-Hoon Hyun ◽  
Jaewang Lee
Keyword(s):  
Neurodegenerative Diseases ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Biogenesis ◽  
Mitochondrial Function ◽  
Redox Homeostasis ◽  
Protein Aggregates ◽  
Sirtuin 1 ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Cellular Signalling

Neurodegenerative diseases are accompanied by oxidative stress and mitochondrial dysfunction, leading to a progressive loss of neuronal cells, formation of protein aggregates, and a decrease in cognitive or motor functions. Mitochondrial dysfunction occurs at the early stage of neurodegenerative diseases. Protein aggregates containing oxidatively damaged biomolecules and other misfolded proteins and neuroinflammation have been identified in animal models and patients with neurodegenerative diseases. A variety of neurodegenerative diseases commonly exhibits decreased activity of antioxidant enzymes, lower amounts of antioxidants, and altered cellular signalling. Although several molecules have been approved clinically, there is no known cure for neurodegenerative diseases, though some drugs are focused on improving mitochondrial function. Mitochondrial dysfunction is caused by oxidative damage and impaired cellular signalling, including that of peroxisome proliferator-activated receptor gamma coactivator 1α. Mitochondrial function can also be modulated by mitochondrial biogenesis and the mitochondrial fusion/fission cycle. Mitochondrial biogenesis is regulated mainly by sirtuin 1, NAD+, AMP-activated protein kinase, mammalian target of rapamycin, and peroxisome proliferator-activated receptor γ. Altered mitochondrial dynamics, such as increased fission proteins and decreased fusion products, are shown in neurodegenerative diseases. Due to the restrictions of a target-based approach, a phenotype-based approach has been performed to find novel proteins or pathways. Alternatively, plasma membrane redox enzymes improve mitochondrial function without the further production of reactive oxygen species. In addition, inducers of antioxidant response elements can be useful to induce a series of detoxifying enzymes. Thus, redox homeostasis and metabolic regulation can be important therapeutic targets for delaying the progression of neurodegenerative diseases.

Improving hepatic mitochondrial biogenesis as a postulated mechanism for the antidiabetic effect ofSpirulina platensisin comparison with metformin

2019 ◽  
Vol 44 (4) ◽  
pp. 357-364 ◽  
Author(s):  
Ghaleb A. Oriquat ◽  
Mennatallah A. Ali ◽  
Shimaa A. Mahmoud ◽  
Rania M.H.M. Eid ◽  
Rania Hassan ◽  
...  
Keyword(s):  
Lipid Profile ◽  
Mitochondrial Biogenesis ◽  
Regulatory Element ◽  
Fasting Blood Glucose ◽  
Arthrospira Platensis ◽  
Diabetic Rats ◽  
Peroxisome Proliferator ◽  
Mtdna Copy Number ◽  
Peroxisome Proliferator Activated Receptor ◽  
Anti Inflammatory

Various nutritional and medicinal potencies have been accredited to metabolites from the cyanobacteria, Spirulina platensis (Arthrospira platensis) sp. Hence, our study was designed to examine whether the Spirulina supplementation would possess beneficial effects in type 2 diabetes mellitus (T2DM) in comparison with metformin. High-fat diet/low-dose streptozotocin (HFD/STZ) model was adopted and the diabetic rats were orally treated with metformin (200 mg/kg) or Spirulina (250 or 500 or 750 mg/kg) for 30 days. Spirulina ameliorated the HFD/STZ-induced elevation of fasting blood glucose, insulin, and hepatic enzymes. Moreover, Spirulina successfully rectified disrupted serum lipid profile and exhibited an anti-inflammatory effect via tumor necrosis factor-α and adiponectin modulation. On the molecular level, Spirulina reduced the expression of hepatic sterol regulatory element binding protein-1c (SREBP-1c), confirming its lipotropic effect. Furthermore, Spirulina amended compromised hepatic mitochondrial biogenesis signaling by significantly increasing peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α), mitochondrial transcription factor A (Tfam), and mitochondrial DNA (mtDNA) copy number. On almost all parameters, the highest dose of Spirulina showed the best effects, which were comparable to that of metformin. To our knowledge, our study is the first to attribute the various aspects of the effect of Spirulina to the SREBP-1c and PGC-1α/Tfam/mtDNA pathways in liver. The present results clearly proved that Spirulina modulated glucose/lipid profile and exhibited prominent anti-inflammatory properties through SREBP-1c inhibition and hepatic mitochondrial biogenesis enhancement. Thus, Spirulina can be considered as an add-on to conventional antidiabetic agents and might influence the whole dynamics of the therapeutic approaches in T2DM.

scholarly journals PPAR-gamma induced AKT3 expression increases levels of mitochondrial biogenesis driving prostate cancer

Oncogene ◽  
2021 ◽  
Vol 40 (13) ◽  
pp. 2355-2366
Author(s):  
Laura C. A. Galbraith ◽  
Ernest Mui ◽  
Colin Nixon ◽  
Ann Hedley ◽  
David Strachan ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Mitochondrial Biogenesis ◽  
Nuclear Export ◽  
Epithelial To Mesenchymal Transition ◽  
Ppar Gamma ◽  
Peroxisome Proliferator ◽  
Serine Threonine Kinase ◽  
Peroxisome Proliferator Activated Receptor ◽  
Mesenchymal Transition ◽  
And Function

AbstractPeroxisome Proliferator-Activated Receptor Gamma (PPARG) is one of the three members of the PPAR family of transcription factors. Besides its roles in adipocyte differentiation and lipid metabolism, we recently demonstrated an association between PPARG and metastasis in prostate cancer. In this study a functional effect of PPARG on AKT serine/threonine kinase 3 (AKT3), which ultimately results in a more aggressive disease phenotype was identified. AKT3 has previously been shown to regulate PPARG co-activator 1 alpha (PGC1α) localisation and function through its action on chromosome maintenance region 1 (CRM1). AKT3 promotes PGC1α localisation to the nucleus through its inhibitory effects on CRM1, a known nuclear export protein. Collectively our results demonstrate how PPARG over-expression drives an increase in AKT3 levels, which in turn has the downstream effect of increasing PGC1α localisation within the nucleus, driving mitochondrial biogenesis. Furthermore, this increase in mitochondrial mass provides higher energetic output in the form of elevated ATP levels which may fuel the progression of the tumour cell through epithelial to mesenchymal transition (EMT) and ultimately metastasis.

Screening for asymptomatic diabetes and metabolic comorbidities in pediatric patients during therapy for acute lymphoblastic leukemia

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Valerie Larouche ◽  
Caroline Bellavance ◽  
Pauline Tibout ◽  
Sebastien Bergeron ◽  
David Simonyan ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Acute Lymphoblastic Leukemia ◽  
Pediatric Patients ◽  
Lymphoblastic Leukemia ◽  
Fasting Blood Glucose ◽  
Metabolic Disturbances ◽  
Metabolic Complications ◽  
Glucose Levels ◽  
Oncology Unit ◽  
Hba1c Levels

Abstract Objectives Chronic metabolic disturbances related to cancer treatment are well reported among survivors of pediatric acute lymphoblastic leukemia (ALL). However, few studies have investigated the incidence of these complications during the phase of chemotherapy. We evaluated the incidence of acute metabolic complications occurring during therapy in our cohort of patients diagnosed with ALL. Methods A prospective study involving 50 ALL pediatric patients diagnosed and treated between 2012 and 2016 in our oncology unit. We collected weight, blood pressure, fasting plasma glucose and hemoglobin A1C (HBA1c) levels during the two years of therapy. Results Obesity and overweight occurred in 43 and 25%, respectively among patients and have been reached at 12 months of chemotherapy. About 26% of the patients developed high blood pressure and 14% experienced hyperglycemias without meeting diabetes criteria. There was a significant decrease of HBA1c levels between the beginning and the end of therapy (p<0.0001). Conclusions Increase of body mass index in our ALL pediatric patients occurred during the first months of therapy and plateaued after a year of treatment. We should target this population for early obesity prevention. HbA1c levels measured during therapy did not reveal diabetes criteria. Hence, fasting blood glucose levels are sufficient to monitor ALL pediatric patients’ glycemia.

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