Expression Levels Of PGC-1α Research Articles

The Effect of Six Weeks of High Intensity Interval Training on eNOS and PGC-1α Gene Expression in the Heart Tissue of Male Obese Rats

Background: Nowadays, obesity can affect heart function and induced atherosclerosis, high blood pressure, and heart arrhythmia, which has become a major problem for global health. Objectives: The present study aimed to review the effect of six weeks of high-intensity interval training (HIIT) on gene expression levels of PGC-1α and eNOS in the heart tissue of obese male rats. Methods: In this experimental study, 14 high-fat diet (HFD)-induced obese rats were divided into two groups of control and training. Also, 7 rats were placed in a non-obese control group to investigate the effects of obesity on research variables. During six weeks, rats in the training group performed HIIT three days per week. After six weeks, all rats were sacrificed, and their heart tissue was removed to measure the PGC-1α and eNOS gene expression. We used one-way ANOVA with Tukey’s post hoc tests (P ≤ 0.05) for statistical analysis. Results: HFD significantly decreased PGC-1α (P = 0.04) and eNOS (P = 0.001) gene expression, but HIIT significantly increased PGC-1α (P = 001) and eNOS (P = 0.001) gene expression. Conclusions: HIIT seems to improve cardiac gene expression levels of PGC-1α and eNOS of male obese rats.

MBNL1-Associated Mitochondrial Dysfunction and Apoptosis in C2C12 Myotubes and Mouse Skeletal Muscle.

We explored the interrelationship between a tissue-specific alternative splicing factor muscleblind-like 1 (MBNL1) and peroxisome proliferator-activated receptor-γ coactivator 1-α (PGC-1α), B-cell lymphoma 2 (Bcl-2) or Bcl-2-associated X protein (Bax) in C2C12 myotubes and mouse skeletal muscle to investigate a possible physiological role of MBNL1 in mitochondrial-associated apoptosis of skeletal muscle. Expression level of PGC-1α and mitochondrial membrane potential evaluated by the fluorescence ratio of JC-1 aggregate to monomer in C2C12 myotubes were suppressed by knockdown of MBNL1. Conversely, the ratio of Bax to Bcl-2 as well as the apoptotic index in C2C12 myotubes was increased by MBNL1 knockdown. In plantaris muscle, on the other hand, not only the minimum muscle fiber diameter but also the expression level of MBNL1 and PGC-1α in of 100-week-old mice were significantly lower than that of 10-week-old mice. Furthermore, the ratio of Bax to Bcl-2 in mouse plantaris muscle was increased by aging. These results suggest that MBNL1 may play a key role in aging-associated muscle atrophy accompanied with mitochondrial dysfunction and apoptosis via mediating PGC-1α expression in skeletal muscle.

Preventive effects of medium-chain triglycerides supplementation on the oxidative capacity in skeletal muscle under cachectic condition.

Cachexia is a multifactorial condition characterized by muscle mass loss and induces metabolic dysfunction of the skeletal muscles. The preventive effects of medium-chain triglycerides (MCT) supplementation on the oxidative capacity in skeletal muscle under cachectic condition were investigated in the present study. ICR mice were randomly divided into four groups; control, lipopolysaccharide (LPS), LPS plus long-chain triglycerides (LCT) and LPS plus MCT supplementation. LCT and MCT oil were administered to the LPS + LCT and LPS + MCT groups orally (5.0 g/kg body weight/day) by a catheter for one week. Cachexia was induced in the LPS, LPS + LCT, and LPS + MCT groups via LPS injection (7.5 mg/kg body weight, i.p.) after the supplementation. LPS induced a reduction of ketone bodies concentration in blood plasma. LPS also induced a decrease in succinate dehydrogenase activity and PGC-1α expression level in tibialis anterior muscles. Meanwhile, MCT supplementation suppressed a decrease in ketone bodies concentration and succinate dehydrogenase activity. In addition, MCT supplementation increased the level of citrate synthase activity in the muscles. These results suggested the preventive effect of MCT supplementation on oxidative capacity in skeletal muscle and the involvements of ketone bodies regulation under cachectic condition.

Effects Of Mild Hypoxic Conditions On Mrna Expression Of Spinal Cord In The Young And Old Mouse

We have developed a method to evaluate motoneuron plasticity by real-time RT-PCR analysis for whole spinal cord. PURPOSE: In this study, we examined effects of mild hypoxic conditions on mRNA expression of spinal cord as well as skeletal muscle in young and old mouse. METHODS: Young (12-week old, n=16) and old (20-month old, n=17) mice were divided into three groups of control, continuous hypoxia, and intermittent hypoxia. Both hypoxic groups were subjected to exposure for 5 days under oxygen concentration of 16%. The intermittent hypoxic group was exposed six times to an oxygen concentration of 16% intermittently every hour for 12 hours of the light day of the day. Immediately after completion of the exposure, the spinal cord (Cervical 3 - 6 and Lumber 2 - 5) as well as muscles (diaphragm and gastrocnemius muscles) were removed and mRNA expression levels were investigated using real time RT-PCR system. RESULTS: Although the mRNA expression levels of PGC1α and VEGF-A were significantly (P < 0.05) higher in diaphragm than gastrocnemius muscles, these mRNA expressions levels were not affected by hypoxic stimulation. While, the mRNA expression levels of muscle remodeling factors (Pax7, MyoD, BDNF, and MHCe) were significantly (P < 0.05) higher in hypoxic condition than control group. Compared with young mice, the expression levels of inflammatory cytokine receptor (IL-6Rα) and neurotrophic factors (BDNF, VEGF-A) of muscles increased in old mice. The increased expressions may be considered to be an indispensable adaptive change for age-related changes in skeletal muscle including neuromuscular junction. In the both hypoxia groups, the mRNA expression level of neurotrophic factors (VEGF-A, FGF2) significantly (P < 0.05) increased in the cervical, but not in the lumbar spinal cord. CONCLUSIONS: We concluded that the mRNA expressions of trophic factor were changed by hypoxic stimulation not only in the muscle but also in the cervical spinal cord.

Hydrogen Gas Alleviates Sepsis-Induced Brain Injury by Improving Mitochondrial Biogenesis Through the Activation of PGC-α in Mice.

Sepsis-associated encephalopathy (SAE) affects approximately one-third of septic patients, and there is a lack of effective therapeutics for SAE. Hydrogen gas is a new medical gas that exerts anti-inflammation, antioxidation, and anti-apoptotic effects and can effectively protect septic mice. Mitochondrial dysfunction, which can be improved by mitochondrial biogenesis, is a type of molecular pathology in sepsis. Peroxisome proliferator-activated receptor gamma co-activator 1α (PGC-1α), which can be inhibited by SR-18292, is the key regulatory factor of mitochondrial biogenesis. Therefore, we investigated the effects of hydrogen gas on mitochondrial function and mitochondrial biogenesis in mice with SAE and the related regulatory mechanisms. Cecal ligation and puncture was used to induce sepsis in mice. The mice with hydrogen gas therapy were exposed to 2% H2 inhalation for 1 h beginning at both 1 and 6 h after operation, and mice were also injected with a PGC-1α inhibitor, SR-18292. We recorded the 7-day survival rates of the mice and detected their cognitive function using a Y-maze test. The Nissl bodies in the CA1 region of hippocampus were observed by Nissl staining, and the apoptotic cells were observed by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay staining. The mitochondrial membrane potential (MMP), adenosine triphosphate (ATP) level, and mitochondrial respiratory chain complexes I and II were analyzed using commercial kits. The mitochondrial morphology was observed by transmission electron microscopy. The expression levels of PGC-1α, nuclear respiratory factor 2 (NRF2), and mitochondrial transcription factor A (Tfam) were detected by Western blot analysis. The present study showed that hydrogen gas therapy increased the 7-day survival rate, improved cognitive function, increased the mitochondrial function (MMP, ATP level, complex I activity) and expression of mitochondrial biogenesis parameters (PGC-1α, NRF2, Tfam). However, the injection of SR-18292 (a PGC-1α inhibitor) decreased mitochondrial function, PGC-1α activation, and expression of NRF2 and Tfam. Therefore, these results indicate that hydrogen gas alleviates sepsis-induced brain injury in mice by improving mitochondrial biogenesis through the activation of PGC-1α.

High‐Fat Induces Cardiac Remodeling via Dysbiosis of the Gut Microbiome

Although consumption of a high‐fat diet (HFD) causes metabolic changes, the mechanisms remain unknown. We hypothesize that HFD instigates dysbiosis, and cardiac muscle remodeling by inducing matrix metalloproteinases (MMPs) that lead to an increase in the white fat contents in the body, and an intervention with a probiotic (PB) reverses these phenomena, in part, by increasing lipolysis (PGC‐1α, and UCP1), fat‐browning, and decreasing lipogenesis. To test this hypothesis, we used wild type (WT) mice and fed them with HFD for a period of 16‐weeks with or without a PB in the drinking water. Cardiac injury was measured by estimating the CKMB activity. The results demonstrated that CKMB activity was robust in the HFD mice. Interestingly, CKMB activity was normalized in the PB treated mice group. Free fatty acids (FFAs), and methylation levels were increased but the butyrate entity was decreased in the HFD mice group, suggesting ensuing of the “dysbiotic 1‐carbon metabolism” phenotype. Further, expression levels of PGC‐1α, and UCP1 were measured by Western blottings, and the MMP activity was estimated by zymography. The collagen histology was also performed on tissue samples collected from the mice. Contractions of isolated single myocytes were recorded employing an “Ion‐Optic” system, and the cardiac functions were scored by Echocardiography. The vasculature in the mice‐hearts was analyzed by BaSo4 X‐ray angiography, and the blood flow rate was studied using the Laser Doppler imaging system. Together, our findings suggest that mice fed with HFD gained significant weights, and they showed an increase in the systemic blood pressure, along with alterations of the vascular structures, and blood flow rates. Interestingly, some of the dysregulated effects were normalized by PB treatment. Furthermore, the extent of fibrosis, and MMP‐2 activity were quite robust in the HFD fed mice, and again the treatment with PB was able to mitigate cardiac tissue remodeling. Myocytes’ calcium‐dependent contractions were disrupted by consumption of the HFD, and treatment with PB was again able to mitigate the deleterious effects. We conclude that HFD induces dysbiosis of the “1‐carbon metabolism”, and treatment with PB creates eubiosis, and browning of the body fat.

Function of hesperidin alleviating inflammation and oxidative stress responses in COPD mice might be related to SIRT1/PGC-1α/NF-κB signaling axis

Purpose: Hesperidin has anti-inflammatory and anti-oxidant stress effects, but its functions in chronic obstructive pulmonary disease (COPD) remains unknown. This study analyzed the role of hesperidin in COPD mice, aiming to provide a basis for the hesperidin application.Materials and methods: Mice were injected with cigarette smoke extract (CSE) to construct COPD models and then treated with budesonide or hesperidin. Hematoxylin-eosin (HE) and TUNEL assays were used to observe the pathological changes and cell death of lung tissue. The levels of interleukin (IL)-6, IL-8, malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) in bronchoalveolar lavage fluid (BLAF), as well as myeloperoxidase (MPO) content in lung tissues were confirmed. The expression levels of SIRT1, PGC-1α, and p65 proteins were measured by western blotting (WB) analysis.Results: CSE induced inflammatory cell infiltration and cell death in the lung tissues of mice, whereas budesonide and hesperidin effectively alleviated these pathological changes. The levels of IL-6, IL-8, and MDA in BLAF and pulmonary MPO content in the COPD mice were effectively increased, while the levels of SOD and CAT in BLAF were decreased, which could be reversed by budesonide and hesperidin. Moreover, the addition of budesonide or hesperidin reliably accelerated the expression levels of PGC-1α and SIRT1 but suppressed the phosphorylation of p65 in COPD mice. In general, high-dose hesperidin had a stronger regulatory effect on COPD mice.Conclusions: Hesperidin alleviated inflammation and oxidative stress responses in CES-induced COPD mice, associated with SIRT1/PGC-1α/NF-κB signaling axis, which might become a new direction for COPD treatment.

Radioactivity Reduction of 2-Deoxy-2-[18F] Fluoro-D-Glucose by Milk and Ursodeoxycholic Acid in Preclinical Study.

2-Deoxy-2-[18F] fluoro-d-glucose positron emission tomography (18F-FDG-PET) is a less-invasive and widely used diagnostic tool for detection of malignant tumors. However, prolonged retention of 18F-FDG in the body increases radiation exposure. This study evaluated the effect of oral administration of milk and ursodeoxycholic acid (UDCA) in terms of reducing radiation exposure by 18F-FDG. 18F-FDG radioactivity was measured using a digital γ counter in the whole body and in various organs of rats after oral administration of milk and milk plus UDCA (milk + UDCA). Western blotting was performed to measure the expression levels of G6Pase, HK 2, CREB, FoxO1, and PGC-1α in the brain, liver, small intestine, and large intestine to assess the mechanism underlying the reduction in radiation exposure from 18F-FDG by oral administration of milk and UDCA. We found a significant reduction in 18F-FDG radioactivity in the whole body and in the brain, liver, and small and large intestines. Expression of G6Pase was significantly increased in the above-mentioned organs in the milk and milk + UDCA groups. Expression of HK 2 was significantly decreased in the brain and small intestine in the milk and milk + UDCA groups. CREB, FoxO1, and PGC-1α expression levels in the brain, liver, and small intestine were increased in the milk and milk + UDCA groups. However, expression of PGC-1α in the large intestine in the milk and milk + UDCA groups was significantly decreased compared with that in the control group. The present study demonstrated that administration of milk and UDCA increased G6Pase expression levels and 18F-FDG release from the tissue. These results suggest milk and UDCA could be used to reduce radiation exposure from 18F-FDG after image acquisition. The mechanisms underpinning this phenomenon should be explored in a human study.

The Effect of Periodic Exercise and Resveratrol Supplementation on the Expression of Pparg Coactivator-1 Alpha and Pyruvate Dehydrogenase Kinase Genes in Gastrocnemius Muscle of Old Rats With Type 2 Diabetes

Aims: Type 2 diabetes is the result of complex interactions between genetic and environmental factors that affect fat and glucose metabolism. The purpose of this study was to determine the effect of periodic exercise and resveratrol supplement on the expression levels of Pparg Coactivator 1-Alpha (PGC-1α) and Pyruvate Dehydrogenase Kinase (PDK4) genes in gastrocnemius muscle of old rates with type 2 diabetes. Methods &amp; Materials: 42 male rats (mean age= 40-50 weeks; mean body weight= 250-300 g) were randomly divided into 6 groups: healthy-control, diabetic-control, Diabetic+Periodic Exercise, Diabetic+Supplement, Diabetic+Periodic Exercise+Supplement and Saline. The type 2 diabetes was induced by intraperitoneal injection of Streptozotocin (50 mg/kg body weight). The exercise protocol consisted of 10 sets of 1-min activities at 50% intensity and a 2-min rest period between sets, and each week the speed was increased by 2 meters per minute. The exercises were performed for eight weeks. Resveratrol supplement was injected intraperitoneally daily at a dose of 20 mg/kg body weight. The expressions of PDK4 and PGC-1α in the gastrocnemius muscle were measured by real time Polymerase Chain Reaction (PCR) method. Findings: highest expression level of PDK4 and PGC-1α genes in gastrocnemius muscle was observed in the diabetic group received both periodic exercise and Resveratrol supplement and the lowest level was reported in the diabetic-control and saline groups. Conclusion The combination of resveratrol supplementation and periodic exercise can have beneficial effects on PDK4 and PGC-1α expression levels in the gastrocnemius muscle of old rats with type 2 diabetes and reduce the risks of diabetes-related complications.

Cerebrolysin Ameliorates Focal Cerebral Ischemia Injury Through Neuroinflammatory Inhibition via CREB/PGC-1α Pathway.

Neuroinflammation is one of the important factors aggravating brain injury after ischemic stroke. We aimed to investigate the effects of cerebrolysin (CBL) on neuroinflammation in vivo and in vitro and the underlying mechanisms. The gene expressions of pro-inflammatory factors and anti-inflammatory factors were analyzed by real time PCR in rat transient middle cerebral artery occlusion (tMCAO) model, lipopolysaccharides-induced neuroinflammatory mice model and LPS-treated mouse primary microglia cells. The neuroprotective effects of CBL were evaluated by infarct size, Longa test and Rotarod test for long-term functional recovery in rats subjected to ischemia. The role of CREB/PGC-1α pathway in anti-neuroinflammatory effect of CBL was also determined by real time PCR and Western blotting. In the tMCAO model, administration of CBL at 3 h post-ischemia reduced infarct volume, promoted long-term functional recovery, decreased the gene expression of pro-inflammatory factors and increased the gene expression of anti-inflammatory factors. Correspondingly, in LPS-induced neuroinflammatory mice model, CBL treatment attenuated sickness behavior, decreased the gene expression of pro-inflammatory factors, and increased the gene expression of anti-inflammatory factors. In in vitro and in vivo experiments, CBL increased the protein expression levels of PGC-1α and phosphorylated CREB to play anti-inflammatory effect. Additionally, the application of the specific CREB inhibitor, 666-15 compound could effectively reverse the anti-inflammatory effect of CBL in primary mouse microglia cells and anti-ischemic brain injury of CBL in rats subjected to tMCAO. In conclusion, CBL ameliorated cerebral ischemia injury through reducing neuroinflammation partly via the activation of CREB/PGC-1α pathway and may play a therapeutic role as anti-neuroinflammatory agents in the brain disorders associated with neuroinflammation.

Endurance exercise resistance to lipotoxic cardiomyopathy is associated with cardiac NAD+/dSIR2/PGC-1α pathway activation in old Drosophila.

ABSTRACTLipotoxic cardiomyopathy is caused by excessive lipid accumulation in myocardial cells and it is a form of cardiac dysfunction. Cardiac PGC-1α overexpression prevents lipotoxic cardiomyopathy induced by a high-fat diet (HFD). The level of NAD+ and Sir2 expression upregulate the transcriptional activity of PGC-1α. Exercise improves cardiac NAD+ level and PGC-1α activity. However, the relationship between exercise, NAD+/dSIR2/PGC-1α pathway and lipotoxic cardiomyopathy remains unknown. In this study, flies were fed a HFD and exercised. The heart dSir2 gene was specifically expressed or knocked down by UAS/hand-Gal4 system. The results showed that either a HFD or dSir2 knockdown remarkably increased cardiac TG level and dFAS expression, reduced heart fractional shortening and diastolic diameter, increased arrhythmia index, and decreased heart NAD+ level, dSIR2 protein, dSir2 and PGC-1α expression levels. Contrarily, either exercise or dSir2 overexpression remarkably reduced heart TG level, dFAS expression and arrhythmia index, and notably increased heart fractional shortening, diastolic diameter, NAD+ level, dSIR2 level, and heart dSir2 and PGC-1α expression. Therefore, we declared that exercise training could improve lipotoxic cardiomyopathy induced by a HFD or cardiac dSir2 knockdown in old Drosophila. The NAD+/dSIR2/PGC-1α pathway activation was an important molecular mechanism of exercise resistance against lipotoxic cardiomyopathy.

Neuroprotective effects of resveratrol against oxygen glucose deprivation induced mitochondrial dysfunction by activation of AMPK in SH-SY5Y cells with 3D gelatin scaffold

Ischemic stroke arising from the sudden blockage of arteries in the brain, is a common and serious brain damaging problem worldwide, often leading to disability or death. The oxygen glucose deprivation (OGD) model was created to improve understanding of hypoxia- and hypoglycemia-induced neuronal cell injury, and provide an in vitro surrogate to assess novel treatments for cerebral hypoxia-ischemia. AMP-activated protein kinase (AMPK) is a critical neuroprotective regulator of energy homeostasis, metabolism and cell survival. However, the neuroprotective mechanisms by which AMPK achieves these beneficial effects in human SH-SY5Y neural cells exposed to OGD are still not well understood. Resveratrol is a potent activator of AMPK suggesting it may have therapeutic potential as a neuroprotective agent. Therefore, we hypothesized the AMPK activator resveratrol protects against OGD-mediated impairment of human SH-SY5Y neuronal cells. The novelty of the experiment using a 3D gelatin scaffold cell culture assay, we have tested the potential of 3D systems to mimic the endogenous neuronal environment and have applied these systems to study the effect of OGD on neuronal cells with/without resveratrol. Here we show resveratrol reverses, via AMPK-dependent downregulation of caspase 3 and 9 activity, the OGD-mediated decreases in SH-SY5Y cell viability on a 3D gelatin scaffold. In addition, treatment with OGD decreases mRNA levels of AMPK and the neuroprotective genes (Bcl-2 and CREB); however, co-treatment with resveratrol significantly normalizes these effects. Importantly, resveratrol improves the expression of AMPK and p-AMPK in OGD-exposed SH-SY5Y cells. Resveratrol also significantly rescues SH-SY5Y cells from OGD-mediated mitochondrial deficiency (lower D-loop level, mitochondrial mass, maximal respiratory function, COX activity, and mitochondrial membrane potential). Resveratrol also rescues the transcript expression levels of PGC1α and mitochondrial genes (NRF-1 and Tfam) in OGD-treated SH-SY5Y cells. These findings extend our mechanistic understanding of the central role of AMPK in OGD-related neuronal impairment, and may serve as basis for implementing new therapeutic strategies in the treatment of ischemic stroke.

Effect of electroacupuncture combined with treadmill exercise on body weight and expression of PGC-1α， Irisin and AMPK in skeletal muscle of diet-induced obesity rats

To investigate the effect of electroacupuncture (EA) plus treadmill exercise on the expression of peroxisome proliferator activated receptor γ coactivator 1α(PGC-1α), Irisin, AMP-activated protein kinase (AMPK) in skeletal muscle of diet-induced obesity (DIO) rats, so as to explore its mechanism underlying body reduction promotion. Forty-two male SD rats were divided into normal diet (control, n＝10), high fat diet (model), EA, treadmill exercise and EA plus treadmill exercise (combination) groups (n＝8 in each of the latter 4 groups). The obesity model was established by feeding the rats with high fat diet. EA (2 Hz/15 Hz, 1 mA) was applied to bilateral "Zusanli" (ST36) and "Tianshu" (ST25) for 30 min, 5 times per week for a total of 8 weeks. Rats of the treadmill exercise group were forced to perform exercise on a treadmill (16 m/min) for 30 min, 5 times per week for a total of 8 weeks. Rats in the combination group received the above-mentioned two methods. During the treatment, rats in the control group were fed with normal fodder, rats in other groups were fed with high fat fodder, and their body weight was measured once a week. The expression levels of PGC-1α， fibronectin type Ⅲ domain containing 5 (FNDC5), AMPK mRNA and protein of skeletal muscle were measured by quantitative real-time PCR and Western blot，respectively. After modeling, the body weight was significantly increased (P<0.05), and the expression levels of PGC-1α and FNDC5 mRNA and protein, AMPK mRNA and phosphorylated AMPK (p-AMPK) protein in the skeletal muscle were considerably decreased in the model group relevant to the control group (P<0.05). Following the treatment, the body weight was significantly down-regulated, while the expression levels of PGC-1α and FNDC5 mRNAs and proteins, AMPK mRNA and p-AMPK protein were obviously up-regulated in the EA, treadmill exercise and combination groups relevant to the model group (P<0.05). The therapeutic effect of EA plus treadmill exercise was significantly superior to those of both simple EA and simple treadmill exercise in down-regulating the body weight, as well as in up-regulating the expression of PGC-1α and FNDC5 mRNAs and proteins, AMPK mRNA, and p-AMPK protein (P<0.05). Both EA and treadmill exercise can significantly increase the expression of PGC-1α， FNDC5 and p-AMPK in skeletal muscle of DIO rats, suggesting their efficacy in restoring fatty acid oxidation in skeletal muscle cells and improving mitochondrial function, which may contribute to their function in body reduction. The therapeutic effect of EA plus treadmill exercise is better than that of simple EA and simple treadmill exercise.

Danqi Tablet (丹七片) Regulates Energy Metabolism in Ischemic Heart Rat Model through AMPK/SIRT1-PGC-1α Pathway

To investigate the cardioprotective effect of Danqi Tablet (DQT, ) on ischemic heart model rats and the regulative effect on energy metabolism through peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α). Rat ischemic heart model was induced by ligation of left anterior descending coronary artery. Totally 40 Sprague-Dawley rats were randomly divided into sham group, model group, DQT group (1.5 mg/kg daily) and trimetazidine (TMZ) group (6.3 mg/kg daily) according to a random number table, 10 rats in each group. Twenty-eight days after continuous administration, cardiac function was assessed by echocardiography and the structures of myocardial cells were observed by hematoxylin-eosin staining. The level of adenosine triphosphate (ATP) in myocardial cells was measured by ATP assay kit. Expressions level of key transcriptional regulators, including PGC-1α, Sirtuin 1 (SIRT1), AMP-activated protein kinase (AMPK), and downstream targets of PGC-1α, such as mitofusin 1 (MFN1), mitofusin 2 (MFN2) and superoxide dismutase 2 (SOD2) were measured by Western blot. Expression level of PGC-1α was examined by immunohistochemical staining. The rat ischemic heart model was successfully induced and the heart function in model group was compromised. Compared with the model group, DQT exerted cardioprotective effects, up-regulated the ATP production in myocardial cells and inhibited the infiltration of inflammatory cells in the margin area of infarction of the myocardial tissues (P<0.01). The expressions of PGC-1α, SIRT1 and AMPK were increased in the DQT group (all P<0.05). Furthermore, the downstream targets, including MFN1, MFN2 and SOD2 were up-regulated (P<0.05 or P<0.01). Compared with the TMZ group, the expression levels of PGC-1α, MFN1 and SOD2 were increased by DQT treatment (P<0.05 or P<0.01). DQT regulated energy metabolism in rats with ischemic heart model through AMPK/SIRT1 -PGC-1α pathway. PGC-1α might serve as a promising target in the treatment of ischemic heart disease.

Effects of myostatin deficiency on PGC-1α and FNDC5 expression in three different murine muscle types

Myostatin (MSTN) is a key negative regulator of muscle growth and development. Skeletal, cardiac, and smooth muscles were isolated from MSTN knockout (MSTN−∕−) and control mice to investigate the effect of knocking out MSTN on peroxisome proliferator-activated receptor 1 coactivator (PGC-1α)-III and fibronectin domain 5 (FNDC5) expression. Various molecular biology techniques were used to analyze the changes in PGC-1α-FNDC5 in different muscle types from MSTN−∕− mice. The expression levels of PGC-1α and FNDC5 in the skeletal, cardiac, and smooth muscles of MSTN−∕− mice differed from those in the skeletal, cardiac, and smooth muscles of normal mice. This study revealed that knocking out MSTN resulted in inconsistent PGC-1α and FNDC5 expression in specific muscles. It proved for the first time that MSTN deletion attenuated the expression of PGC-1α and FNDC5 in three different murine muscle types. MSTN deletion may have additional effects on the status ofFNDC5 expression. Further research, however, is needed to confirm this conclusion.

Disruption of mitochondrial homeostasis with artemisinin unravels anti-angiogenesis effects via auto-paracrine mechanisms.

Rationale: Tumor angiogenesis promotes tumor development, progression, growth, and metastasis. Metronomic chemotherapy involves the frequent administration of low-dose chemotherapeutic agents to block angiogenic activity and reduce side effects.Methods: MDA-MB-231 cells were treated with various concentrations of artemisinin (ART) and vinorelbine (NVB) and the cytotoxic effects of ART/NVB were determined using the CCK-8 assay. Mitochondrial reactive oxygen species (ROS) levels, mitochondrial membrane potential (∆Ψm) and mass were assessed using MitoSOX, TMRE and MitoTracker green staining. Western blot analysis was used to quantify the expression of autophagy-related proteins. Herein, by using bioinformatics analysis and experimental verification, we identified CREB as a master in MDA-MB-231 cells.Results: We found that artemisinin (ART), which exhibits anti-angiogenic and anti-cancer effects via mitochondrial regulation, synergized with vinorelbine (NVB) to inhibit MDA-MB-231 cell proliferation. ART and NVB cooperated to regulate mitochondrial biogenesis. CREB acted as a crucial regulator of PGC1α and VEGF, which played critical roles in NVB-dependent growth factor depletion. Moreover, CREB suppression significantly reversed mitochondrial dysfunction following ART/NVB co-treatment. In addition, combination treatment with ART and NVB significantly suppressed tumor growth in a nude mouse xenograft model, with downregulated CREB and PGC1α expression levels observed in tumor biopsies, in agreement with our in vitro and ex vivo data.Conclusions: These findings support the hypothesis that ART affects cancer and endothelial cells by targeting the auto-paracrine effects of VEGF to suppress mitochondrial biogenesis, angiogenesis, and migration between cancer cells and endothelial cells.

AdipoRon prevents l-thyroxine or isoproterenol-induced cardiac hypertrophy through regulating the AMPK-related pathway.

Cardiac hypertrophy is a risk factor which can intrigue heart failure. In the present study, we explored whether AdipoRon attenuates isoprenaline (ISO) or l-thyroxine-induced cardiac hypertrophy in Sprague-Dawley (SD) rats and whether the anti-hypertrophy effect is mediated by AMPK-related pathway. Here, cardiac hypertrophy was induced by injection of l-thyroxine or ISO in SD rats. In the treatment group, AdipoRon was co-administered. We examined the effects of AdipoRon on cardiac hypertrophy and hypertrophy signaling pathway. The weight of SD rats was recorded every day. Rats were killed for collection of blood and heart under anesthesia. The left heart weight and heart weight were weighed. Paraffin-embedded heart tissue regions (4 μm) were stained with hematoxylin and eosin or Masson to detect left heart hypertrophy and myocardial fibrosis. The serum BNP levels were determined by using an enzyme-linked immunosorbent assay. The mRNA levels of ANP, BNP, PGC-1α, and ERRα were evaluated by real-time PCR analysis. The protein expression levels of PGC-1α, ERRα, and pAMPK/AMPK were determined by western blot analysis. The results showed that AdipoRon significantly reversed heart weight (HW)/body weight (BW) ratio, left ventricular (LV)/BW ratio, serum BNP level and the mRNA level of ANP and BNP induced by ISO or l-thyroxine. ISO or l-thyroxine reduced both the mRNA level and protein level of ERRα and PGC-1α, and also reduced the protein level of pAMPK/AMPK. However, AdipoRon reversed ISO or l-thyroxine-induced changes of pAMPK/AMPK, ERRα, and PGC-1α. Our data indicated that the effects of AdipoRon are mediated partly by activating AMPK-related pathway, and AdipoRon plays a potential role in the prevention of cardiac hypertrophy.

Metformin Increases Cardiac Rupture After Myocardial Infarction via the AMPK-MTOR/PGC-1α Signaling Pathway in Rats with Acute Myocardial Infarction.

BackgroundCardiac rupture often occurs after acute myocardial infarction due to complex and unclear pathogenesis. This study investigated whether metformin increases the incidence of cardiac rupture after myocardial infarction through the AMPK-MTOR/PGC-1α signaling pathway.Material/MethodsAn acute myocardial infarction (MI) mouse model was established. A series of experiments involving RT-qPCR, Western blot, TUNEL staining, and Masson staining were performed in this study.ResultsMyocardial infarction occurred, resulting in the cardiac rupture, and the expression level of PGC-1α increased in the cardiac myocardium. Meanwhile, the proportion of myocardial NT-PGC-1α/PGC-1α decreased. The expression level of myocardial PGC-1α in MI mice with cardiac rupture after MI was significantly higher than that in the mice without cardiac rupture, and the ratio of myocardial NT-PGC-1α/PGC-1α was low. In addition, increasing the dose of metformin significantly increased the incidence of cardiac rupture after myocardial infarction in MI mice. High-dose metformin caused cardiac rupture in MI mice. Moreover, high-dose metformin (Met 2.0 nM) reduces the proportion of NT-PGC-1α/PGC-1α in primary cardiomyocytes of SD mice (SD-NRVCs [Neonatal rat ventricular cardiomyocytes]), and its effect was inhibited by Compound C (AMPK inhibitor). Further, after 3 days of treatment with high-dose metformin in MI mice, myocardial fibrin synthesis decreased and fibrosis was significantly inhibited. Meanwhile, cardiomyocyte apoptosis increased significantly. With the increase in metformin concentration, the expression level of myocardial LC3b gradually increased in MI mice, suggesting that metformin enhances the autophagy of cardiomyocytes.ConclusionsThese results suggest that metformin increases cardiac rupture after myocardial infarction through the AMPK-MTOR/PGC-1α signaling pathway.

Effects of eicosapentaenoic acid intake on denervation-induced mitochondrial adaptation in mouse skeletal muscle

Eicosapentaenoic acid (EPA) is an omega-3 polyunsaturated fatty acid that is abundant in fish oil, and has anti-inflammatory or anti-obesity effects. However, the effects of EPA supplementation on mitochondrial content and dynamics (fusion and fission) in skeletal muscle has not been elucidated. We investigated the effects of EPA intake for 4 weeks on denervation-induced mitochondrial adaptation in mice skeletal muscle. ICR mice (male, 8 weeks old) were daily administrated olive oil (control) or EPA at a dose of 300 mg/kg body weight by gavage for 4 weeks. After 2 weeks of oil intake, mice underwent unilateral sciatic nerve transection surgery. The hindlimb without surgery served as the sham-operated control. Body and skeletal muscle weights did not differ between the control and the EPA groups. Peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) and oxidative phosphorylation (OXPHOS) proteins were significantly decreased by denervation surgery. Denervation also induced the reduction of mitochondrial fusion molecules and the increase of mitochondrial fission molecules. Expression levels of PGC-1α and mitochondrial respiration protein MTCO1 were higher in the EPA group than in the control (olive oil) group. In addition, the EPA group contained higher levels of mitochondrial fusion protein OPA1. Our results suggest that EPA intake prevents the reduction of mitochondrial content and fusion proteins in denervated skeletal muscle.

Bamboo shoot fiber improves insulin sensitivity in high-fat diet-fed mice

The aim of this study was to evaluate the role of bamboo shoot fiber (BSF) in regulating insulin sensitivity in mice. Two BSFs were obtained from D. hamiltonii and D. latiforus. C57BL/6 mice were fed a low-fat diet or a high-fat diet with 10% fiber as cellulose (HFC), or two BSFs (HFDH or HFDL) for 13 weeks. Compared with the HFC group, HFDH and HFDL groups exhibited considerably less body weight gain, lower levels of fasting glucose and insulin, and lower values of glucose areas under the curve during glucose and insulin tolerance tests. BSF groups also had lower glucoses stimulated insulin concentrations. In addition, more phosphorylation of Akt in insulin target tissues was associated with higher protein expression levels of PGC-1α and phosphorylated AMPK and p38 in BSF fed mice. These results indicated that BSF improved insulin sensitivity in high-fat diet-fed mice through enhancing insulin signaling and activating PGC-1α.