Proliferator-activated Receptor Gamma Coactivator 1-alpha Research Articles

Upregulation of PGC-1α expression by pioglitazone mediates prevention of sepsis-induced acute lung injury.

The imbalance between pro-inflammatory M1 and anti-inflammatory M2 macrophages plays a critical role in the pathogenesis of sepsis-induced acute lung injury (ALI). Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) may modulate macrophage polarization toward the M2 phenotype by altering mitochondrial activity. This study aimed to investigate the role of the PGC-1α agonist pioglitazone (PGZ) in modulating sepsis-induced ALI. A mouse model of sepsis-induced ALI was established using cecal ligation and puncture (CLP). An in vitro model was created by stimulating MH-S cells with lipopolysaccharide (LPS). qRT-PCR was used to measure mRNA levels of M1 markers iNOS and MHC-II and M2 markers Arg1 and CD206 to evaluate macrophage polarization. Western blotting detected expression of peroxisome proliferator-activated receptor gamma (PPARγ) PGC-1α, and mitochondrial biogenesis proteins NRF1, NRF2, and mtTFA. To assess mitochondrial content and function, reactive oxygen species levels were detected by dihydroethidium staining, and mitochondrial DNA copy number was measured by qRT-PCR. In the CLP-induced ALI mouse model, lung tissues exhibited reduced PGC-1α expression. PGZ treatment rescued PGC-1α expression and alleviated lung injury, as evidenced by decreased lung wet-to-dry weight ratio, pro-inflammatory cytokine secretion (tumor necrosis factor-α, interleukin-1β, interleukin-6), and enhanced M2 macrophage polarization. Mechanistic investigations revealed that PGZ activated the PPARγ/PGC-1α/mitochondrial protection pathway to prevent sepsis-induced ALI by inhibiting M1 macrophage polarization. These results may provide new insights and evidence for developing PGZ as a potential ALI therapy.

Dietary supplementation with capsaicinoids alleviates obesity in mice fed a high-fat-high-fructose diet.

Capsaicinoids are the pungent compounds in chili peppers. The present study investigated the effect of capsaicinoids on obesity in mice induced by a high-fat-high-fructose diet. Thirty-two male C57BL/6J mice were randomly divided into four groups (n = 8) and fed one of the following diets, namely, a low-fat diet (LFD), a high-fat-high-fructose diet (HFF), an HFF + 0.015% capsaicinoids (LCP), and an HFF + 0.045% capsaicinoids (HCP), for 12 weeks. Results showed that capsaicinoids significantly reversed HFF-induced obesity. Supplementation with capsaicinoids improved glucose tolerance, reduced plasma lipids, and attenuated inflammation. Capsaicinoids also reduced hepatic lipid accumulation by upregulating the expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). In addition, capsaicinoids enhanced the production of fecal short-chain fatty acids (SCFAs) and increased the fecal excretion of lipids. Gut microbiota analysis revealed that capsaicinoids decreased the Firmicutes/Bacteroidetes ratio and beneficially reconstructed the microbial community. However, the effects of capsaicinoids on intestinal villus length and lipid tolerance were negligible. In conclusion, capsaicinoids effectively attenuated HFF-induced obesity and metabolic syndrome by favorably modulating lipid metabolism, improving SCFA production, and reshaping gut microbial structure.

Unveiling the anti-obesity potential of Kemuning (Murraya paniculata): A network pharmacology approach.

Obesity has become a global issue that affects the emergence of various chronic diseases such as diabetes mellitus, dysplasia, heart disorders, and cancer. In this study, an integration method was developed between the metabolite profile of the active compound of Murraya paniculata and the exploration of the targeting mechanism of adipose tissue using network pharmacology, molecular docking, molecular dynamics simulation, and in vitro tests. Network pharmacology results obtained with the skyline query technique using a block-nested loop (BNL) showed that histone acetyltransferase p300 (EP300), peroxisome proliferator-activated receptor gamma (PPARG), and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A) are potential targets for treating obesity. Enrichment analysis of these three proteins revealed their association with obesity, thermogenesis, energy metabolism, adipocytokines, fat cell differentiation, and glucose homeostasis. Metabolite profiling of M. paniculata leaves revealed sixteen active compounds, ten of which were selected for molecular docking based on drug-likeness and ADME results. Molecular docking results between PPARG and EP300 with the ten active compounds showed a binding affinity value of ≤ -5.0 kcal/mol in all dockings, indicating strong binding. The stability of the protein-ligand complex resulting from docking was examined using molecular dynamics simulations, and we observed the best average root mean square deviation (RMSD) of 0.99 Å for PPARG with trans-3-indoleacrylic acid, which was lower than with the native ligand BRL (2.02 Å). Furthermore, the RMSD was 2.70 Å for EP300 and the native ligand 99E, and the lowest RMSD with the ligand (1R,9S)-5-[(E)-2-(4-Chlorophenyl)vinyl]-11-(5-pyrimidinylcarbonyl)-7,11-diazatricyclo[7.3.1.02,7]trideca-2,4-dien-6-one was 3.33 Å. The in vitro tests to validate the potential of M. paniculata in treating obesity showed that there was a significant decrease in PPARG and EP300 gene expressions in 3T3-L1 mature adipocytes treated with M. paniculata ethanolic extract starting at concentrations 62.5 μg/ml and 15.625 μg/ml, respectively. These results indicate that M. paniculata can potentially treat obesity by disrupting adipocyte maturation and influencing intracellular lipid metabolism.

Mitochondria-derived peptide is an effective target for treating streptozotocin induced painful diabetic neuropathy through induction of activated protein kinase/peroxisome proliferator-activated receptor gamma coactivator 1alpha -mediated mitochondrial biogenesis.

Painful Diabetic Neuropathy (PDN) is a common diabetes complication that frequently causes severe hyperalgesia and allodynia and presents treatment challenges. Mitochondrial-derived peptide (MOTS-c), a novel mitochondrial-derived peptide, has been shown to regulate glucose metabolism, insulin sensitivity, and inflammatory responses. This study aimed to evaluate the effects of MOTS-c in streptozocin (STZ)-induced PDN model and investigate the putative underlying mechanisms. We found that endogenous MOTS-c levels in plasma and spinal dorsal horn were significantly lower in STZ-treated mice than in control animals. Accordingly, MOTS-c treatment significantly improves STZ-induced weight loss, elevation of blood glucose, mechanical allodynia, and thermal hyperalgesia; however, these effects were blocked by dorsomorphin, an adenosine monophosphate-activated protein kinase (AMPK) inhibitor. In addition, MOTS-c treatment significantly enhanced AMPKα1/2 phosphorylation and PGC-1α expression in the lumbar spinal cord of PDN mice. Mechanistic studies indicated that MOTS-c significantly restored mitochondrial biogenesis, inhibited microglia activation, and decreased the production of pro-inflammatory factors, which contributed to the alleviation of pain. Moreover, MOTS-c decreased STZ-induced pain hypersensitivity in PDN mice by activating AMPK/PGC-1α signaling pathway. This provides the pharmacological and biological evidence for developing mitochondrial peptide-based therapeutic agents for PDN.

Protective Effect of Dihydromyricetin Against ExerciseInduced Muscle Damage and Its Mechanism

Objective To investigate the protective effect of dihydromyricetin (DHM) against exercise-induced muscle damage (EIMD) in mice and its potential mechanism.Methods Adult male C57BL/6J mice were randomly divided into control group (CG), exercise group (EG), and exercise + 100 mg/kg weight ·d DHM (DHM) group. The intervention lasted for four weeks, during which the animals in the EG and DHM groups were subjected to exercise training for 1 h per day. The day after the training, a 90-min treadmill exercise (slope: 0 and speed: 18 m/min) was conducted in both EG and DHM groups. Samples of blood and gastrocnemius muscles were harvested from the three groups 24 h after the exercise, followed by the measurement of serum creatine kinase (CK) and lactate dehydrogenase (LDH) activities, total superoxide dismutase (T-SOD) activity, malondialdehyde (MDA), and skeletal muscle mitochondrial enzyme complex I and II activities. Histological changes in the skeletal muscle were observed by transmission electron microscopy, and the protein expressions of mitochondrial function-related pathways were detected by Western blotting.Results Skeletal muscle morphological changes and mitochondrial damage were alleviated in the DHM group compared to those in the EG. The activities of EIMD markers CK and LDH and the level of lipid peroxidation were notably repressed and the serum T-SOD activity was enhanced after DHM intervention. Western blotting demonstrated that the expressions of sirtuin type 3 (SIRT3), estrogen-related receptor alpha, and peroxisome proliferator-activated receptor-gamma coactivator-1 alpha in the skeletal muscle of mice increased after the DHM intervention.Conclusion DHM can relieve EIMD in mice, possibly by promoting the recovery of the mitochondrial structure and function in the skeletal muscle of mice after high-intensity exercise via the activation of the SIRT3 signaling pathway.

Gromwell (Lithospermum erythrorhizon) Attenuates High-Fat-Induced Skeletal Muscle Wasting by Increasing Protein Synthesis and Mitochondrial Biogenesis.

Gromwell (Lithospermum erythrorhizon, LE) can mitigate obesity-induced skeletal muscle atrophy in C2C12 myotubes and high-fat diet (HFD)-induced obese mice. The purpose of this study was to investigate the anti-skeletal muscle atrophy effects of LE and the underlying molecular mechanism. C2C12 myotubes were pretreated with LE or shikonin, and active component of LE, for 24 h and then treated with 500 μM palmitic acid (PA) for an additional 24 h. Additionally, mice were fed a HFD for 8 weeks to induced obesity, and then fed either the same diet or a version containing 0.25% LE for 10 weeks. LE attenuated PA-induced myotubes atrophy in differentiated C2C12 myotubes. The supplementation of LE to obese mice significantly increased skeletal muscle weight, lean body mass, muscle strength, and exercise performance compared with those in the HFD group. LE supplementation not only suppressed obesity-induced skeletal muscle lipid accumulation, but also downregulated TNF-α and atrophic genes. LE increased protein synthesis in the skeletal muscle via the mTOR pathway. We observed LE induced increase of mitochondrial biogenesis and upregulation of oxidative phosphorylation related genes in the skeletal muscles. Furthermore, LE increased the expression of peroxisome proliferator-activated receptor-gamma coactivator-1 alpha and the phosphorylation of adenosine monophosphate-activated protein kinase. Collectively, LE may be useful in ameliorating the detrimental effects of obesity-induced skeletal muscle atrophy through the increase of protein synthesis and mitochondrial biogenesis of skeletal muscle.

Malvidin promotes PGC-1α/Nrf2 signaling to attenuate the inflammatory response and restore mitochondrial activity in septic acute kidney injury

Acute kidney injury (AKI) in sepsis is a vital and dangerous organ failure caused by an infection-induced dysregulation of the host reaction. Malvidin possesses significant anti-inflammatory and antioxidant bioactivities. This study explored the critical roles of malvidin in sepsis AKI and the crosstalk among mitochondrial function, nucleotide-binding oligomerization-like receptor 3 (NLRP3) inflammasome and nuclear factor erythroid 2 (Nrf2) signaling pathway. First, C57BL/6 mice were administered lipopolysaccharide intraperitoneally for 6 h to create an AKI model of sepsis. Hematoxylin-eosin staining and serum biomarker assays showed that malvidin protected from AKI in sepsis. Real-time fluorescence quantitative polymerase chain reaction analysis revealed that malvidin was able to inhibit inflammatory cytokines and mediators. Western blot assays indicated that malvidin suppressed NLRP3 inflammasome activation and enhanced antioxidant properties. Additionally, human renal tubular epithelial cells were stimulated by lipopolysaccharide/adenosine triphosphate to establish an NLRP3 inflammasome activation model in vitro, and in line with findings in vivo, malvidin significantly inhibited NLRP3 inflammasome activation. Furthermore, our data indicate that malvidin restored mitochondrial quality and function, reduced reactive oxygen species production, increased mitochondrial membrane potential, enhanced mitochondrial DNA copy number, and promoted peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) nuclear translocation. Moreover, inhibitor blockade assays indicated that both PGC-1α and Nrf2 affected the inhibition of the NLRP3 inflammasome by malvidin. Finally, immunoprecipitation assays showed that malvidin promoted PGC-1α and Nrf2 interactions. Overall, malvidin alleviated lipopolysaccharide-induced sepsis AKI, improved mitochondrial function and mitochondrial biogenesis, and inhibited the NLRP3 inflammasome through the PGC-1α/Nrf2 signaling pathway, suggesting that malvidin might translate into clinical applications for sepsis AKI therapy.

Hesperidin counteracts chlorpyrifos-induced neurotoxicity by regulating oxidative stress, inflammation, and apoptosis in rats.

Chlorpyrifos (CPF), considered one of the most potent organophosphates, causes a variety of human disorders including neurotoxicity. The current study was designed to evaluate the efficacy of hesperidin (HSP) in ameliorating CPF-induced neurotoxicity in rats. In the study, rats were treated with HSP (orally, 50 and 100mg/kg) 30min after giving CPF (orally, 6.75mg/kg) for 28 consecutive days. Molecular, biochemical, and histological methods were used to investigate cholinergic enzymes, oxidative stress, inflammation, and apoptosis in the brain tissue. CPF intoxication resulted in inhibition of acetylcholinesterase (AChE) and butrylcholinesterase (BChE) enzymes, reduced antioxidant status [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione (GSH)], and elevation of malondialdehyde (MDA) levels and carbonic anhydrase (CA) activities. CPF increased histopathological changes and immunohistochemical expressions of 8-OHdG in brain tissue. CPF also increased levels of glial fibrillary acidic protein (GFAP) and nuclear factor kappa B (NF-κB) while decreased levels of nuclear factor erythroid 2-related factor 2 (Nrf-2), heme oxygenase-1 (HO-1) and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α). Furthermore, CPF increased mRNA transcript levels of caspase-3, Bax, PARP-1, and VEGF, which are associated with apoptosis and endothelial damage in rat brain tissues. HSP treatment was found to protect brain tissue by reducing CPF-induced neurotoxicity. Overall, this study supports that HSP can be used to reduce CPF-induced neurotoxicity.

CircHIPK3 relieves vascular calcification via mediating SIRT1/PGC-1α/MFN2 pathway by interacting with FUS

BackgroundCircular RNAs (circRNAs) have been reported to regulate the biological processes of human diseases. CircHIPK3 has been implicated in vascular calcification, but the downstream regulatory mechanisms remain unclear. Our study aimed to understand the regulatory function of circHIPK3 in vascular calcification.MethodsCircHIPK3 expression in atherosclerosis (AS) serum samples and vascular smooth muscle cells (VSMCs) calcification model was assessed by quantitative real-time polymerase chain reaction (qRT-PCR). The binding relationships between fused in sarcoma (FUS) and circHIPK3 or sirtuin 1 (SIRT1) were verified by RNA immunoprecipitation (RIP) assay and RNA pull-down assays. Alkaline phosphatase (ALP) activity and alizarin red staining assays were performed to evaluate the biological effect of β-glycerophosphate (β-GP) and circHIPK3 on calcium deposition. qRT-PCR and western blot assays were used to examine the effect of β-GP, circHIPK3, SIRT1, mitofusin 2 (MFN2), and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) on VSMCs calcification and the expression of calcification-related proteins.ResultsIn AS serum samples and VSMCs calcification model, the expression of circHIPK3 was significantly reduced. CircHIPK3 overexpression inhibited ALP activity and calcium deposition in β-GP-induced VSMCs. Moreover, circHIPK3 could recruit FUS to further stabilize SIRT1 mRNA. CircHIPK3 promoted MFN2 expression to alleviate VSMCs calcification via activating SIRT1/PGC-1α signaling.ConclusionThe positive regulation of circHIPK3/FUS/SIRT1/PGC-1α/MFN2 signaling pathway contributed to the alleviate VSMCs calcification, revealing a novel regulatory axis for vascular calcification.

Functional and transcriptional sequelae of cardiomyocyte telomere shortening and their pathologic relevance in dilated cardiomyopathy and ischemic heart failure

Abstract Background Heart failure (HF) is associated with cardiomyocyte (CM) telomere shortening. Sequelae have been described with the telomere-p53-mitochondrion model. P53 deficiency only partially ameliorates mitochondrial defects in telomerase deficient mice hinting at additional pathways. Purpose We assessed the cardiac phenotype and transcriptome of early/advanced telomere shortening and evaluated the pathological relevance by correlation to published HF datasets. Methods Male (6-8w) telomerase RNA-component deficient mice, early (generation 2, mTRG2) and advanced (mTRG5) were phenotyped vs age-matched C57BL/6 mice (B6). Adult CMs from mTRG2/G5 vs B6 mice were characterized (live imaging, quantitative fluorescence in situ hybridization (Q-FISH) and transcriptome analysis (microarray Mouse MTA 1.0)). Gene expression analysis was performed (Ingenuity Pathway Analysis, Qiagen) and correlated to comparable datasets from > 120 000 curated datasets. Results CMs exhibited significant telomere shortening in mTR(-/-) mice increasing with every generation (mTRG2/G5 p<0.0001 vs B6). In parallel, echocardiography revealed increasing defects of left ventricular (LV) systolic function (LVEF, mTRG5 <0.01 vs B6), LV global longitudinal strain mTRG2/G5 p<0.001 vs B6) and LV contractile reserve (mTRG2/G5 p<0.05 vs B6). Live imaging showed increasing impairment of mitochondrial polarization with all energy substrates (mTRG2/G5 p<0.0001 vs B6). Transcriptome analysis revealed 357/2906 differentially expressed genes (DEGs) in mTRG2/G5-CMs vs B6-CMs (fold change <-1.5 or >1.5 and p-value <0.05). Upstream Regulator (UR) analysis revealed significant overrepresentation of numerous regulators including angiotensinogen (z-score 7.5, p-value 1.1E-32), transforming growth factor (TGF)-b1 (z-score 7.5, p-value 2.2E-60), interleukin (IL)-1 (z-score 5.6, p-value 1.1E-26), IL-6 (expression fold change 11.3, z-score 6.9 p-value 2.65E-32), IL-17A (z-score 4.8, p-value 4.4E-27) and NFkB (z-score 6.0 p-value 4.9E-19). Activation of TP53 (z-score 5.8, p-value 5.3E-31) and inhibition of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A) (z-score -4.4, p-value 6.3E-19) confirmed the relevance of the p53-mitochondrion-axis. Analysis matching revealed a significant overlap of gene expression patterns in the same direction (positive z-score) between mTR-/--mice and all comparable datasets of dilated (DCM) and ischemic cardiomyopathy (ICM) (human/mouse), the overlap increasing with increasing telomere shortening (e.g. DCM vs mTRG2: z-score 17.7, UR p-value 1.5E-16; DCM vs mTRG5: z-score 56.8, UR-value 1.5E-62). Matching to datasets after cardiac regeneration (e.g. after left ventricular assist device implantation) revealed a reversal of gene expression patterns (negative z-score). Conclusions Our results reveal the large extent of transcriptional alterations upon cardiac telomere shortening and support their central role in the pathogenesis of HF.

Effect of different intensities aerobic exercise to cardiac angiogenesis regulation on Wistar rats

The adaptation response of myocardium angiogenesis stimulated by specific exercise intensities remains unclear. The aims of this study is to explore the effect of different intensities aerobic exercise to cardiac angiogenesis regulation via HIF-1α, PGC-1α, VEGF, and CD34+ in Wistar rats. Wistar rats were divided into control and exercise groups. Exercise groups were trained on a treadmill for 12 weeks, 30 min/day for 5 days with low, moderate, and high-intensity groups. The rats were sacrificed, and the myocardium was collected and preserved at -80°C until used. Cardiac protein samples were extracted and run for Western blotting using the specific antibodies: hypoxia-inducible factor (HIF)-1α, Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), vascular endothelial growth factor (VEGF), and Cluster of differentiation 34 (CD34+). Results showed that protein expression of HIF-1α, PGC-1α, VEGF, and CD34+ was increased significantly by different intensities in the exercise group compared to the control. A correlation statistics test showed that there was a strong correlation effect of HIF-1α on VEGF protein expression in low (p=0.047) and high intensity exercise groups (p=0.009), but no effect was found in the moderate groups. In addition, there was a significant strong effect of PGC-1α on VEGF protein expression in the moderate groups (p=0.037), but no effect was found in other groups. In conclusion, different exercise intensities induce a different modulation pattern of proteins which might be responsible for cardiac adaptation, especially angiogenesis.

5-Aza-2'-deoxycytidine-mediated DNA hypomethylation with and without concurrent insulin resistance suppresses myotube mitochondrial capacity.

Type 2 diabetes is characterized by elevated blood glucose and reduced insulin sensitivity in target tissues. Moreover, reduced mitochondrial metabolism and expressional profile of genes governing mitochondrial metabolism (such as peroxisome proliferator-activated receptor gamma coactivator 1-alpha [PGC-1α]) are also reduced during insulin resistance. Epigenetic regulation via DNA methylation of genes including PGC-1α may contribute to diminished mitochondrial capacity, while hypomethylation of PGC-1α (such as that invoked by exercise) has been associated with increased PGC-1α expression and favorable metabolic outcomes. The purpose of the present report is to characterize the effects of DNA hypomethylation on myotube metabolism and expression of several related metabolic targets. C2C12 myotubes were treated with 5-Aza-2'-deoxycytidine (5-Aza) for either 24 or 72 hboth with and without hyperinsulinemic-induced insulin resistance. Mitochondrial and glycolytic metabolism were measured via oxygen consumption and extracellular acidification rate, respectively. Metabolic gene and protein expression were assessed via quantitative real time polymerase chain reactionand western blot analysis, respectively. Though expression of PGC-1α and other related targets remained unaltered, insulin resistance and 5-Aza treatment significantly reduced mitochondrial metabolism. Similarly, peak glycolytic metabolism was diminished by 5-Aza-treated cells, while basal glycolytic metabolism was unaltered. 5-Aza also reduced the expression of branched-chain amino acid(BCAA) catabolic components, however BCAA utilization was enhanced during insulin resistance with 5-Aza treatment. Together the present work provides proof-of-concept evidence of the potential role of DNA methylation in the regulation of mitochondrial metabolism and the potential interactions with insulin resistance in a model of skeletal muscle.

Cannabidiol Mitigates Lipopolysaccharide-Induced Pancreatic Pathology: A Promising Therapeutic Strategy.

Background: Lipopolysaccharides (LPSs) are a component of certain types of bacteria and can induce an inflammatory response in the body, including in the pancreas. Cannabidiol (CBD), a nonpsychoactive compound found in cannabis, has been shown to have anti-inflammatory effects and may offer potential therapeutic benefits for conditions involving inflammation and damage. The aim of this study was to investigate any potential preventative effects of CBD on experimental LPS-induced pancreatic pathology in rats. Materials and Methods: Thirty-two rats were randomly divided into four groups as control, LPS (5 mg/kg, intraperitoneally [i.p.]), LPS+CBD, and CBD (5 mg/kg, i.p.) groups. Six hours after administering LPS, the rats were euthanized, and blood and pancreatic tissue samples were taken for biochemical, polymerase chain reaction (PCR), histopathological, and immunohistochemical examinations. Results: The results indicated that LPS decreased serum glucose levels and increased lipase levels. It also caused severe hyperemia, increased vacuolization in endocrine cells, edema, and slight inflammatory cell infiltrations at the histopathological examination. Insulin and amylin expressions decreased during immunohistochemical analyses. At the PCR analysis, Silent Information Regulator 2 homolog 1 and peroxisome proliferator-activated receptor gamma coactivator-1 alpha expressions decreased and tumor protein p53 expressions increased in the LPS group. CBD improved the biochemical, PCR, histopathological, and immunohistochemical results. Conclusions: The findings of the current investigation demonstrated that LPS damages both the endocrine and exocrine pancreas. However, CBD demonstrated marked ameliorative effects in the pancreas in LPS induced rat model pancreatitis.

Verbascoside Elicits Its Beneficial Effects by Enhancing Mitochondrial Spare Respiratory Capacity and the Nrf2/HO-1 Mediated Antioxidant System in a Murine Skeletal Muscle Cell Line.

Muscle weakness and muscle loss characterize many physio-pathological conditions, including sarcopenia and many forms of muscular dystrophy, which are often also associated with mitochondrial dysfunction. Verbascoside, a phenylethanoid glycoside of plant origin, also named acteoside, has shown strong antioxidant and anti-fatigue activity in different animal models, but the molecular mechanisms underlying these effects are not completely understood. This study aimed to investigate the influence of verbascoside on mitochondrial function and its protective role against H2O2-induced oxidative damage in murine C2C12 myoblasts and myotubes pre-treated with verbascoside for 24 h and exposed to H2O2. We examined the effects of verbascoside on cell viability, intracellular reactive oxygen species (ROS) production and mitochondrial function through high-resolution respirometry. Moreover, we verified whether verbascoside was able to stimulate nuclear factor erythroid 2-related factor (Nrf2) activity through Western blotting and confocal fluorescence microscopy, and to modulate the transcription of its target genes, such as heme oxygenase-1 (HO-1) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), by Real Time PCR. We found that verbascoside (1) improved mitochondrial function by increasing mitochondrial spare respiratory capacity; (2) mitigated the decrease in cell viability induced by H2O2 and reduced ROS levels; (3) promoted the phosphorylation of Nrf2 and its nuclear translocation; (4) increased the transcription levels of HO-1 and, in myoblasts but not in myotubes, those of PGC-1α. These findings contribute to explaining verbascoside's ability to relieve muscular fatigue and could have positive repercussions for the development of therapies aimed at counteracting muscle weakness and mitochondrial dysfunction.

Electroacupuncture Mediates Fat Metabolism and Autophagy via a Sirt3-Dependent Mechanism in Mice Fed High-Fat Diet.

This study investigates the therapeutic potential of electroacupuncture (EA) on obesity, focusing on its influence on autophagy and energy metabolism, utilizing a high-fat diet (HFD)-induced mouse model. Treatment with EA significantly reduces body weight, fat deposition, and lipid accumulation in HFD-fed mice. Additionally, EA effectively ameliorates metabolic imbalances, reducing blood glucose levels and plasma markers of liver function. At the molecular level, EA enhances the expression of thermogenesis-associated genes in brown adipose tissue and decreases p53 expression, suggesting a decrease in apoptosis. Autophagy in white adipose tissue is inhibited by EA, as demonstrated by the suppression of key autophagy-related proteins. Further experiments highlight the critical role of Sirtuin 3 (Sirt3) in EA's anti-obesity effects. Sirt3 supplementation combined with EA results in reduced body weight, fat deposition, and lipid accumulation, along with modulations in key metabolic indicators. Moreover, EA's modulatory effect on uncoupling protein 1 (Ucp1), Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (Pgc-1α), and p53 is found to be Sirt3 dependent. In conclusion, EA exerts beneficial effects against obesity through Sirt3-dependent modulation of autophagy and energy metabolism, indicating a potential therapeutic approach for obesity and related metabolic disorders.

Effects of myostatin gene knockout on white fat browning and related gene expression in type 2 diabetic mice.

Myostatin (Mstn) plays an important role in adipocyte growth, differentiation and metabolism, leading to the development of obesity. We aimed to explore the effect of Mstn on white fat browning in a mouse model of type 2 diabetes mellitus (T2DM). Twelve wild-type (WT), 12 heterozygous (Mstn(+/-)) and 12 homozygous (Mstn(-/-)) male mice were randomly divided into 6 groups: WT, Mstn(+/-), Mstn(-/-), WT+DM, Mstn(+/-)+DM, and Mstn(-/-)+DM. The first 3 groups were fed normal chow, while the last 3 were fed high-fat diet and administered streptozotocin to generate T2DM. Subsequently, body mass, length, and white and brown fat masses were measured, after which Lee's index, white-brown ratio and fat index were calculated. The serum free fatty acid (FFA) levels were detected using enzyme-linked immunosorbent assay (ELISA). Hematoxylin and eosin (H&E) staining was used to analyze white and brown fat cell morphology. The relative expression levels of peroxisome proliferator-activated receptor-gamma (PPARγ), peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1α), uncoupling protein 1 (UCP1), and cluster of differentiation 137 (CD137) protein were determined with western blotting. The Mstn(-/-) group displayed higher levels of PPARγ, PGC-1α and CD137 proteins in white and brown fat compared to the WT and Mstn(+/-) groups, while the expression level of UCP1 protein in the Mstn(-/-) group was higher than in the WT group. The expression levels of PPARγ, PGC-1α, UCP1, and CD137 proteins in the WT+DM group were lower than in the WT group. Moreover, PPARγ, PGC-1α, UCP1, and CD137 proteins were more highly expressed in the Mstn(-/-)+DM group compared to the WT+DM and Mstn(+/-)+DM groups. The Mstn gene inhibition antagonizes obesity phenotypes, such as white fat accumulation and lipid metabolism derangement caused by T2DM, thus promoting white fat browning.

Hyperbaric oxygen therapy restores wound healing in irradiated gingiva to a similar level to that in healthy gingiva.

This study aimed to investigate the involvement of mitochondrial biogenesis, and determine the extent of fibroblast proliferation and cellular apoptosis, in the gingiva of patients who had undergone head and neck radiation, after receiving hyperbaric oxygen therapy (HBOT), in comparison with normal gingiva. A total of 16 patients who had undergone head and neck radiation with HBOT and six healthy subjects were included in the study. After the completion of radiation therapy, patients received HBOT at 2 ATA for 90 minutes per session, and for 20 sessions per patient. Samples of gingival tissues were then taken. The levels of: transforming growth factor beta (TGF-β); phospho-nuclear factor kappa-light-chain-enhancer of activated B cells (p-NFϰB); nuclear factor kappa-light-chain-enhancer of activated B cells (NFϰB); proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α); phospho-dynamin-related protein 1 at ser616 (p-Drp1ser616); dynamin-related protein 1 (Drp1); Bcl-2-associated X-protein (Bax); and B-cell lymphoma 2 (Bcl-2) were determined using a Western blot. Independent t-test and Chi-squared tests were used in the study. There were no differences in the levels of TGF-β, p-NFϰB, NFϰB, p-Drp1ser616, Drp1, Bax and Bcl-2 between the two groups. However, the level of PGC-1α was greater in irradiated gingival tissues with HBOT than in the healthy gingiva. Radiation-induced impaired wound healing can be improved by HBOT as indicated by levels of apoptosis, mitochondrial dynamics, cell proliferation and inflammation in irradiated gingiva with HBOT to a similar level to normal healthy gingiva. These findings may occur through an increase in mitochondrial biogenesis following HBOT.

Targeted metabolomics reveals the aberrant energy status in diabetic peripheral neuropathy and the neuroprotective mechanism of traditional Chinese medicine JinMaiTong

Diabetic peripheral neuropathy (DPN) is a common and devastating complication of diabetes, for which effective therapies are currently lacking. Disturbed energy status plays a crucial role in DPN pathogenesis. However, the integrated profile of energy metabolism, especially the central carbohydrate metabolism, remains unclear in DPN. Here, we developed a metabolomics approach by targeting 56 metabolites using high-performance ion chromatography-tandem mass spectrometry (HPIC-MS/MS) to illustrate the integrative characteristics of central carbohydrate metabolism in patients with DPN and streptozotocin-induced DPN rats. Furthermore, JinMaiTong (JMT), a traditional Chinese medicine (TCM) formula, was found to be effective for DPN, improving the peripheral neurological function and alleviating the neuropathology of DPN rats even after demyelination and axonal degeneration. JMT ameliorated DPN by regulating the aberrant energy balance and mitochondrial functions, including excessive glycolysis restoration, tricarboxylic acid cycle improvement, and increased adenosine triphosphate (ATP) generation. Bioenergetic profile was aberrant in cultured rat Schwann cells under high-glucose conditions, which was remarkably corrected by JMT treatment. In-vivo and in-vitro studies revealed that these effects of JMT were mainly attributed to the activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK) and downstream peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). Our results expand the therapeutic framework for DPN and suggest the integrative modulation of energy metabolism using TCMs, such as JMT, as an effective strategy for its treatment.

Testosterone deficiency impairs cardiac interfibrillar mitochondrial function and myocardial contractility while inducing oxidative stress.

Clinical studies have shown that low levels of endogenous testosterone are associated with cardiovascular diseases. Considering the intimate connection between oxidative metabolism and myocardial contractility, we determined the effects of testosterone deficiency on the two spatially distinct subpopulations of cardiac mitochondria, subsarcolemmal (SSM) and interfibrillar (IFM). We assessed cardiac function and cardiac mitochondria structure of SSM and IFM after 12 weeks of testosterone deficiency in male Wistar rats. Results show that low testosterone reduced myocardial contractility. Orchidectomy increased total left ventricular mitochondrial protein in the SSM, but not in IFM. The membrane potential, size and internal complexity in the IFM after orchidectomy were higher compared to the SHAM group. However, the rate of oxidative phosphorylation with all substrates in the IFM after orchidectomy was lower compared to the SHAM group. Testosterone replacement restored these changes. In the testosterone-deficient SSM group, oxidative phosphorylation was decreased with palmitoyl-L-carnitine as substrate; however, the mitochondrial calcium retention capacity in IFM was increased. There was no difference in swelling of the mitochondria in either group. These changes in IFM were followed by a reduction in phosphorylated form of AMP-activated protein kinase (p-AMPK-α), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) translocation to mitochondria and decreased mitochondrial transcription factor A (TFAM). Testosterone deficiency increased NADPH oxidase (NOX), angiotensin converting enzyme (ACE) protein expression and reduced mitochondrial antioxidant proteins such as manganese superoxide dismutase (Mn-SOD) and catalase in the IFM. Treatment with apocynin (1.5 mM in drinking water) normalized myocardial contractility and interfibrillar mitochondrial function in the testosterone depleted animals. In conclusion, our findings demonstrate that testosterone deficiency leads to reduced myocardial contractility and impaired cardiac interfibrillar mitochondrial function. Our data suggest the involvement of reactive oxygen species, with a possibility of NOX as an enzymatic source.

A high fat, high sugar diet induces hepatic Peroxisome proliferator-activated receptor gamma coactivator 1-alpha promoter hypermethylation in male Wistar rats

Previously we reported that a high fat, high sugar (HFHS) diet induced adiposity, hyperinsulinaemia, hyperleptinaemia, hypertriglyceridaemia and increased liver mass in male Wistar rats. In the present study, the mechanisms underlying the increased liver mass were further elucidated by assessing hepatic lipid accumulation and the expression and methylation status of key metabolic genes using histology, quantitative real-time PCR and pyrosequencing, respectively. The HFHS diet induced hepatic steatosis, increased hepatic triglycerides (1.8-fold, p < 0.001), and increased the expression of sterol regulatory element-binding transcription factor 1 (Srebf1) (2.0-fold, p < 0.001) and peroxisome proliferator-activated receptor gamma (Pparg) (1.7-fold, p = 0.017) in the liver. The expression of peroxisome proliferator-activated receptor gamma coactivator 1 alpha (Pgc1a) was decreased (2.6-fold, p < 0.010), which was accompanied by hypermethylation (p = 0.018) of a conserved CpG site in the promoter of Pgc1a in HFHS fed rats compared to controls. In silico analysis identified putative binding sites for CCAAT/enhancer-binding protein beta (C/EBPß) and hepatocyte nuclear factor 1 (HNF1) within proximity to the hypermethylated CpG. As Pgc1a is a co-activator of several transcription factors regulating multiple metabolic pathways, hypermethylation of this conserved CpG site in the promoter of Pgc1a may be one possible mechanism contributing to the development of hepatic steatosis in response to a HFHS diet. However, further work is required to confirm the role of Pgc1a in steatosis.