Increased ATP Synthesis Research Articles

Phycocyanin attenuates skeletal muscle damage and fatigue via modulation of Nrf2 and IRS-1/AKT/mTOR pathway in exercise-induced oxidative stress in rats.

Prolonged strenuous exercise induces oxidative stress, leading to oxidative damage, skeletal muscle fatigue, and reduced exercise performance. The body compensates for oxidative stress through antioxidant actions, while related enzymes alone may not overcome excessive oxidative stress during prolonged strenuous exercise. Phycocyanin is an important antioxidant supplement derived from blue-green algae, which may be helpful in this type of situation. This study determined the effects of phycocyanin on exercise performance from prolonged strenuous exercise. Forty Sprague Dawley male rats were divided into 5 groups (n = 8 /group); Control group (C), Exercise group (E), and Exercise with supplement groups receiving low dose (Phycocyanin = 100 mg/kg BW; ELP) and high dose (Phycocyanin = 200 mg/kg BW; EHP) or vitamin C (Vitamin C = 200 mg/kg BW; VC). Phycocyanin was found to decrease oxidative damage markers, muscle fatigue, and muscle atrophy through the activated AKT/mTOR pathway. This was also found to have greater increases in antioxidants via Nrf2 signaling and increases ATP synthesis, GLUT4 transporters, and insulin signaling due to increased IRS-1/AKT signaling. In conclusion, phycocyanin was found to reduce oxidative damage and muscle atrophy, including an increase in insulin signaling in skeletal muscles leading to increased exercise performance in rats.

Docosahexaenoic acid supplementation during porcine oocyte in vitro maturation improves oocyte quality and embryonic development by enhancing the homeostasis of energy metabolism

Although supplementation with docosahexaenoic acid (DHA) during porcine oocyte IVM is well-established, the available data are limited due to the lack of consistency. Moreover, to our knowledge, the anti-oxidant effects of DHA on porcine oocytes have not been reported. Hence, this study aimed to examine the effects of DHA supplementation on the regulation of energy metabolism during porcine oocyte maturation to improve oocyte maturation and embryonic development. By supplementing the IVM medium with various DHA concentrations, 25 μM DHA was identified as the optimal concentration which improved intraoocyte glutathione content and enhanced embryonic development after parthenogenesis. Compared to embryos derived from the control group, those derived from SCNT or IVF showed significantly improved blastocyst formation upon DHA supplementation during IVM. In addition, various transcription factors associated with oocyte development and apoptosis in mature oocytes were beneficially regulated in the DHA-treated oocytes. Moreover, DHA improved the AMP-activated protein kinase (AMPK)-regulatory ability of porcine oocytes and ameliorated nuclear maturation and embryonic development, which were decreased by artificially downregulating AMPK. To our knowledge, this is the first study to examine the effects of DHA as an AMPK regulator on oocyte maturation and embryo development in pigs. Furthermore, DHA addition to the IVM medium upregulated the relative expression of genes associated with mitochondrial potential and lipid metabolism. Therefore, the membrane potential of mitochondria (evaluated based on the JC-1 aggregate/JC-1 monomer ratio) and the levels of fatty acids and lipid droplets in matured oocytes increased, resulting in increased ATP synthesis. In conclusion, the DHA treatment of porcine oocytes with 25 μM DHA during IVM enhances the homeostasis of energy metabolism by improving mitochondrial function and lipid metabolism, leading to improved quality of matured oocytes and enhanced embryonic developmental potential of in vitro produced (IVP) embryos. Thus, 25 μM DHA supplementation could serve as a tool for improving the quality of IVP embryos. The study findings provide a basis for further research on improving the production efficiency of cloned animals by securing high-quality matured oocytes and enhancing energy metabolism in mammalian oocytes, including those of pigs.

Delta opioid peptide [D-ala2, D-leu5]-Enkephalin’s ability to enhance mitophagy via TRPV4 to relieve ischemia/reperfusion injury in brain microvascular endothelial cells

BackgroundLocal brain tissue can suffer from ischaemia/reperfusion (I/R) injury, which lead to vascular endothelial damage. The peptide δ opioid receptor (δOR) agonist [D-ala2, D-leu5]-Enkephalin (DADLE) can reduce apoptosis caused by...

Glucose Regulation of β-Cell KATP Channels: Is a New Model Needed?

The canonical model of glucose-induced increase in insulin secretion involves the metabolism of glucose via glycolysis and the citrate cycle, resulting in increased ATP synthesis by the respiratory chain and the closure of ATP-sensitive K+ (KATP) channels. The resulting plasma membrane depolarization, followed by Ca2+ influx through L-type Ca2+ channels, then induces insulin granule fusion. Merrins and colleagues have recently proposed an alternative model whereby KATP channels are controlled by pyruvate kinase, using glycolytic and mitochondrial phosphoenolpyruvate (PEP) to generate microdomains of high ATP/ADP immediately adjacent to KATP channels. This model presents several challenges. First, how mitochondrially generated PEP, but not ATP produced abundantly by the mitochondrial F1F0-ATP synthase, can gain access to the proposed microdomains is unclear. Second, ATP/ADP fluctuations imaged immediately beneath the plasma membrane closely resemble those in the bulk cytosol. Third, ADP privation of the respiratory chain at high glucose, suggested to drive alternating, phased-locked generation by mitochondria of ATP or PEP, has yet to be directly demonstrated. Finally, the approaches used to explore these questions may be complicated by off-target effects. We suggest instead that Ca2+ changes, well known to affect both ATP generation and consumption, likely drive cytosolic ATP/ADP oscillations that in turn regulate KATP channels and membrane potential. Thus, it remains to be demonstrated that a new model is required to replace the existing, mitochondrial bioenergetics-based model.

The Potential of Bioactive Fish Collagen Oligopeptides against Hydrogen Peroxide-Induced NIH/3T3 and HUVEC Damage: The Involvement of the Mitochondria.

Extensive in vivo investigations have demonstrated the antioxidant properties of fish collagen oligopeptides (FCOPs). One of the main causes of aging and chronic non-communicable diseases is oxidative stress. Therefore, FCOPs have a broad range of applications in illness prevention and delaying aging from the standpoint of the "food is medicine" theory. However, the mechanisms that underpin the antioxidant activity of FCOPs are not completely understood. The specific objective of this essay was to investigate the antioxidant effect of FCOPs and its possible mechanism at the cellular level. Mouse embryonic fibroblasts NIH/3T3 and human vein endothelial cells (HUVECs) were exposed to 200 µM hydrogen peroxide containing different concentrations of FCOPs for 4 h and were supplemented with different concentrations of FCOPs for 24 h. Normal growth medium without FCOPs was applied for control cells. An array of assays was used to evaluate the implications of FCOPs on cellular oxidative stress status, cellular homeostasis, inflammatory levels, and mitochondrial function. We found that FCOPs exerted a protective effect by inhibiting reactive oxygen species (ROS) production, enhancing superoxide dismutase (SOD) and endothelial nitric oxide synthase (eNOS) activities and cell viability, inhibiting cell cycle arrest in the G1 phase, suppressing interleukin-1β (IL-1β), IL-6, matrix metalloproteinase-3 (MMP-3) and intercellular adhesion molecule-1(ICAM-1) secretion, downregulating nuclear factor-kappa B (NF-κB) activity, protecting mitochondrial membrane potential, and increasing ATP synthesis and NAD+ activities in both cells. FCOPs had a stronger antioxidant impact on NIH/3T3 than on HUVECs, simultaneously increasing glutathione peroxidase (GSH-Px) activity and decreasing malondialdehyde (MDA) content in NIH/3T3. These findings indicate that FCOPs have antioxidant effects on different tissue cells damaged by oxidative stress. FCOPs were therefore found to promote cellular homeostasis, inhibit inflammation, and protect mitochondria. Meanwhile, better health outcomes will be achieved by thoroughly investigating the effective dose and intervention time of FCOPs, as the absorption efficiency of FCOPs varies in different tissue cells.

Dietary supplementation with probiotics promotes weight loss by reshaping the gut microbiome and energy metabolism in obese dogs.

Obesity and overweight among companion animals are significant concerns, paralleling the issues observed in human populations. Recent research has highlighted the potential benefits of various probiotics in addressing weight-related changes, obesity, and associated pathologies. In this study, we delved into the beneficial probiotic mechanisms in high-fat-induced obese canines, revealing that Enterococcus faecium IDCC 2102 (IDCC 2102) and Bifidobacterium lactis IDCC 4301 (IDCC 4301) have the capacity to mitigate the increase in body weight and lipid accumulation in obese canines subjected to a high-fat diet and hyperlipidemic Caenorhabditis elegans (C. elegans) strain VS29. Both IDCC 2102 and IDCC 4301 demonstrated the ability to reduce systemic inflammation and hormonal disruptions induced by obesity. Notably, these probiotics induced modifications in the microbiota by promoting lactic acid bacteria, including Lactobacillaceae, Ruminococcaceae, and S24-7, with concomitant activation of pyruvate metabolism. IDCC 4301, through the generation of bacterial short-chain fatty acids and carboxylic acids, facilitated glycolysis and contributed to ATP synthesis. Meanwhile, IDCC 2102 produced bacterial metabolites such as acetic acid and butyric acid, exhibiting a particular ability to stimulate dopamine synthesis in a canine model. This stimulation led to the restoration of eating behavior and improvements in glucose and insulin tolerance. In summary, we propose novel probiotics for the treatment of obese animals based on the modifications induced by IDCC 2102 and IDCC 4301. These probiotics enhanced systemic energy utilization in response to high caloric intake, thereby preventing lipid accumulation and restoring stability to the fecal microbiota. Consequently, this intervention resulted in a reduction in systemic inflammation caused by the high-fat diet.IMPORTANCEProbiotic supplementation affected commensal bacterial proliferation, and administering probiotics increased glycolysis and activated pyruvate metabolism in the body, which is related to propanate metabolism as a result of pyruvate metabolism activation boosting bacterial fatty acid production via dopamine and carboxylic acid specialized pathways, hence contributing to increased ATP synthesis and energy metabolism activity.

Potential role of mitochondrial dysfunction in arrhythmogenesis in coronary artery disease

Introduction. Coronary artery disease (CAD) continues to be the most common pathology in the structure of cardiovascular diseases over the past decades, both in Russia and around the world. In the normal condition, the mitochondria of all body cells have the same function capabilities due to the carriage of the same genome. Therefore, it is possible to assess the respiration activity of cardiomyocyte mitochondria by the respiration of mitochondria from peripheral blood leukocytes.Aim: To compare respiratory activity of mitochondria of peripheral blood leukocytes in patients diagnosed with coronary artery disease and coronary artery disease with developed cardiac rhythm disorders (CRD).Material and methods. The studied groups included 45 patients with CAD without CRD and 39 patients with CAD complicated by CRD. Mitochondria were isolated from peripheral blood leukocytes by differential centrifugation. The rate of oxygen loss in pyruvate-malate and succinate incubation buffers was measured when isolated mitochondria were introduced, as well as when palmitic acid was added to the medium. Oxygen consumption rate for the V3 (active phosphorylating) and V4 (nonphosphorylating) metabolic sates was determined, and on their basis respiratory control coefficient was calculating using the formula V3/V4. Statistical data processing was carried out using STATISTICA 13.0 software.Results. Oxygen consumption rate in mitochondria of patients with uncomplicated CAD and CAD with CRD had no significant differences in either pyruvate-malate or succinate buffers. When palmitic acid was added to the incubation medium, the mitochondria of CAD patients without CRD significantly increased oxygen consumption rate in both incubation media. Mitochondria of CAD patients with CRD did not change oxygen consumption rate in both metabolic states after the addition of palmitic acid in incubation media.Conclusion. On the basis of the data obtained, it can be concluded that the function capabilities of mitochondria in the complicated course of CAD has been exhausted, which manifests itself in the inability to increase ATP synthesis in response to the introduction of additional substrates.

Effect of Burosumab on Muscle Function and Strength, and Rates of ATP Synthesis in Skeletal Muscle in Adults With XLH.

In clinical trials, burosumab ameliorates symptoms of pain, fatigue, and stiffness and improves performance on certain muscle function studies in patients with X-linked hypophosphatemia (XLH). This work aimed to determine if burosumab increases adenosine triphosphate (ATP) synthesis in skeletal muscle of treatment-naive adults with XLH, and if so, whether that correlates with improved muscle function. Ten untreated, symptomatic adults with XLH had ATP synthesis rates measured in the right calf using the 31P magnetic resonance spectroscopy saturation transfer technique. Baseline muscle function tests and symptoms of pain, fatigue, stiffness, and lower-extremity joint pain were quantified. All participants were treated with burosumab, 1 mg/kg every 4 weeks for 12 weeks. ATP synthesis rates and muscle function tests were repeated 2 weeks ("peak") and 4 weeks ("trough") after the third dose of burosumab. All symptoms improved with treatment. Performance on the 6-Minute Walk Test (6MWT) and Sit to Stand (STS) tests also improved. Muscle strength and ATP synthesis rates did not change over the 3 months of the study. When individuals whose performances on the 6MWT and STS test were at or better than the median outcome for those tests were compared to those whose outcomes were below the median, no difference was observed in the rate of change in ATP synthesis. Intracellular muscle concentrations of phosphate were normal. The improvement in the 6MWT and STS test without changes in muscle strength or ATP synthesis rates suggests that reductions in pain, fatigue, and stiffness may partly explain the improved performance. Intracellular phosphate in skeletal muscle is insulated from hypophosphatemia in XLH.

In-vivo Hepatoprotective Evaluation of Sicyos edulis on Wistar Albino Rats

The liver is known for synthesising enzymes, metabolism, and excretion of drugs and food. However, during biological processes, the abnormality occurs in the liver, which becomes a significant global health burden in humans, characterised by loss of synthetic function, breakdown of blood, irregular vitamin K, and localised, permanent changes to parenchymal cells. The study was designed to research the Phytochemical and biological screening of Sicyos edulis leaf for hepatoprotective activity on laboratory animals using paracetamol and methotrexate model for acute incidence. The study evaluated liver toxicity in healthy Wistar albino rats using two in vivo models. Each study group consists of six animals. In the first model, paracetamol p.o. for seven days. Similarly, in the second model, methotrexate was administered (single dose treatment) to animals with 20mg/kg, b.w., p.o. Both models were challenged with methanolic extract of Sicyos edulis leaf (MESEL) of doses 100mg/kg (low) and 200 mg/kg (high) p.o. for seven days, respectively. On day 8th, the blood samples were collected from the tail vein and analysed for various biochemical parameters. MESEL successfully restored the elevated serum biomarker levels in our study. The decrease in aspartate aminotransferase was observed by removing toxic metabolites, the reduction in alanine aminotransferase was due to an increase in ATP synthesis in mitochondria, thereby modulating the balance of liver energy metabolism, and the decrease in alkaline phosphates is due to tissue regeneration, an increase in total protein denotes the restoration of protein imbalance from acute liver injury. At different concentrations, all these effects strengthen the liver, regulate body metabolism, and ultimately inhibit further liver cell damage in favour of their regeneration. Our study also evidences the protective action of MESEL in rats against the Paracetamol and methotrexate model. The study reveals hepatocyte regeneration followed by hepatic restoration in pre-clinical settings. Keywords: Acute liver disease, Sicyos edulis, Silymarin, Methotrexate, Liver enzymes

Brain photobiomodulation therapy on neurological and psychological diseases.

Photobiomodulation (PBM) therapy is an innovative treatment for neurological and psychological conditions. Complex IV of the mitochondrial respiratory chain can be stimulated by red light, which increases ATP synthesis. In addition, the ion channels' light absorption causes the release of Ca2+, which activates transcription factors and changes gene expression. Neuronal metabolism is improved by brain PBM therapy, which also promotes synaptogenesis and neurogenesis as well as anti-inflammatory. Its depression-treating potential is attracting attention for other conditions, including Parkinson's disease and dementia. Giving enough dosage for optimum stimulation using the transcranial PBM technique is challenging because of the rapidly increasing attenuation of light transmission in tissue. Different strategies like intranasal and intracranial light delivery systems have been proposed to overcome this restriction. The most recent preclinical and clinical data on the effectiveness of brain PBM therapy are studied in this review article.

Ginsenoside Rc, an Active Component of Panax ginseng, Alleviates Oxidative Stress-Induced Muscle Atrophy via Improvement of Mitochondrial Biogenesis.

Loss of skeletal muscle mass and function has detrimental effects on quality of life, morbidity, and mortality, and is particularly relevant in aging societies. The enhancement of mitochondrial function has shown promise in promoting muscle differentiation and function. Ginsenoside Rc (gRc), a major component of ginseng, has various pharmacological activities; however, its effect on muscle loss remains poorly explored. In this study, we examined the effects of gRc on the hydrogen peroxide (H2O2)-induced reduction of cell viability in C2C12 myoblasts and myotubes and H2O2-induced myotube degradation. In addition, we investigated the effects of gRc on the production of intracellular reactive oxygen species (ROS) and mitochondrial superoxide, ATP generation, and peroxisome proliferator-activated receptor-gamma co-activator 1α (PGC-1α) activity in myoblasts and myotubes under H2O2 treatment. Furthermore, to elucidate the mechanism of action of gRc, we conducted a transcriptome analysis of myotubes treated with or without gRc under H2O2 treatment. gRc effectively suppressed H2O2-induced cytotoxicity, intracellular ROS, and mitochondrial superoxide production, restored PGC-1α promoter activity, and increased ATP synthesis. Moreover, gRc significantly affected the expression levels of genes involved in maintaining mitochondrial mass and biogenesis, while downregulating genes associated with muscle degradation in C2C12 myotubes under oxidative stress. We provide compelling evidence supporting the potential of gRc as a promising treatment for muscle loss and weakness. Further investigations of the pharmacological effects of gRc under various pathological conditions of muscle loss will contribute to the clinical development of gRc as a therapeutic intervention.

Exploring the Role of NCX1 and NCX3 in an In Vitro Model of Metabolism Impairment: Potential Neuroprotective Targets for Alzheimer's Disease.

Alzheimer's disease (AD) is a widespread neurodegenerative disorder, affecting a large number of elderly individuals worldwide. Mitochondrial dysfunction, metabolic alterations, and oxidative stress are regarded as cooperating drivers of the progression of AD. In particular, metabolic impairment amplifies the production of reactive oxygen species (ROS), resulting in detrimental alterations to intracellular Ca2+ regulatory processes. The Na+/Ca2+ exchanger (NCX) proteins are key pathophysiological determinants of Ca2+ and Na+ homeostasis, operating at both the plasma membrane and mitochondria levels. Our study aimed to explore the role of NCX1 and NCX3 in retinoic acid (RA) differentiated SH-SY5Y cells treated with glyceraldehyde (GA), to induce impairment of the default glucose metabolism that typically precedes Aβ deposition or Tau protein phosphorylation in AD. By using an RNA interference-mediated approach to silence either NCX1 or NCX3 expression, we found that, in GA-treated cells, the knocking-down of NCX3 ameliorated cell viability, increased the intracellular ATP production, and reduced the oxidative damage. Remarkably, NCX3 silencing also prevented the enhancement of Aβ and pTau levels and normalized the GA-induced decrease in NCX reverse-mode activity. By contrast, the knocking-down of NCX1 was totally ineffective in preventing GA-induced cytotoxicity except for the increase in ATP synthesis. These findings indicate that NCX3 and NCX1 may differently influence the evolution of AD pathology fostered by glucose metabolic dysfunction, thus providing a potential target for preventing AD.

PER2 Promotes Odontoblastic/Osteogenic Differentiation of Dental Pulp Stem Cells by Modulating Mitochondrial Metabolism.

Human dental pulp stem cells (hDPSCs) possess remarkable self-renewal and multilineage differentiation ability. PER2, an essential circadian molecule, regulates various physiological processes. Evidence suggests that circadian rhythm and PER2 participate in physiological functions of DPSCs. However, the influence of PER2 on DPSCs' differentiation remains largely unknown. This study aimed to explore the effect and potential mechanism of PER2 on hDPSCs' differentiation. Dental pulp tissues were extracted, and hDPSCs were cultured for in vitro and in vivo experiments. Dorsal subcutaneous transplantation was performed in 6-week-old male BALB/c mice. The hDPSCs' odontoblastic/osteogenic differentiation was assessed, and mitochondrial metabolism was evaluated. The results indicated PER2 expression increasing during hDPSCs' odontoblastic/osteogenic differentiation. Gain- and loss-of function studies confirmed that PER2 promoted alkaline phosphatase (ALP) activity, mineralized nodules deposition, mRNA expression of DSPP, DMP1, COL1A1 and protein expression of DSPP and DMP1 in hDPSCs. Furthermore, PER2 enhanced collagen deposition, osteodentine-like tissue formation and DSPP expression in vivo. Mitochondrial metabolic evaluation aimed to investigate the mechanism of PER2-mediated hDPSC odontoblastic/osteogenic differentiation, which showed that PER2 increased ATP synthesis, elevated mitochondrial membrane potential and changed expression of proteins regulating mitochondrial dynamics. This study demonstrated that PER2 promoted hDPSCs' odontoblastic/osteogenic differentiation, which involved mitochondrial metabolic change.

Anti-inflammatory and analgesic potentials of fermented Citrullus vulgaris with mutant and non-mutant strains of Bacillus subtilis to produce condiment (ogiri)

BackgroundOxidative stress leading to degenerative diseases has become the leading cause of health issues. The use of non-steroidal anti-inflammatory drugs have be associated with complications. The development of nutraceuticals/functional foods that can modulate oxidative stress becomes very necessary. Mutated Bacillus subtilis (B. subtilis) have been reported to produce D-ribose, having ameliorative effects on pro-inflammatory cytokine and increased ATP synthesis. AimsThe present study investigated analgesic and anti-inflammatory effects of ogiri samples fermented with mutant (modified) and non-mutant strains of B. subtilis in α-carrageenan-induced rats. MethodsInflammation and pain were induced via α-carrageenan, while indomethacin and ogiri samples were used for treatment. Mobility and inflammatory volumes, pro-inflammatory cytokines, E-NTPDase activities, antioxidant activities and levels, hepatic and renal markers were investigated. ResultsIt was shown that some of the ogiri fermented with mutant strains of Bacillus subtilis samples ameliorated α-carrageenan-induced inflammatory oedema and painful movements. The percentage inhibition ranged from 18.69 ± 1.98–66.35 ± 2.97, with high percentage inhibition of oedema observed with samples IDC22, AAC70, AAC65, AAH22, AAD10, AAD51, and AAD30 (67.02 ± 1.98, 66.35 ± 2.97, 61.21 ± 2.31, 63.55 ± 1.32, 61.22 ± 2.31, 59.81 ± 0.66 and 59.35 ± 2.32) respectively. The reduction rate and mobility ranged from 5.30 to 10.40 mm and 169.00–288.50 min. The samples mentioned above also showed better amelioration with reduction rates (10.4, 9.85, 9.65, 10.1, 9.85. 9.85 and 9.70), and mobility values (257.00, 273.50, 261.00, 268.00, 271.50, 258.50, and 257.50) than other samples. The E-NTPDase activity ranged from 10.191 to 13.369 and showed energy restoration on some ogiri samples AAC70, AAC65, AAC22, AAH22, AAD10, AAD51, and AAD30 (12.558, 11.882, 11.288, 11.242, 12.324, 11.807 and 11.616) compared to the standard drug (9.798). Pro-inflammatory cytokines, inflammatory markers, antioxidants, hepatic and renal enzymes, and concentrations altered were restored in the same samples mentioned above. ConclusionThe modified ogiri samples, especially AAC70, can be applied as analgesic and anti-inflammatory agents.

Effect of Direct Current Electric Fields on Cone Like Retinal Photoreceptor Cells.

Studies show that electric fields are used as therapy during nerve and tissue injuries along with trans-retinal stimulation. However, cellular and molecular changes induced by such treatments remain largely unknown especially in retinal photoreceptor cells. In vitro studies show that direct current electric fields (dcEF) were known to influence cell division, polarity, shape, and motility. Here we could characterize for the first time the reactions of 661W, a retinal cone photoreceptor especially regarding organelle polarization, membrane polarization of mitochondria, O2 consumption, ATP/ADP ratio and gene expression. The 661W cells were stimulated with a constant dcEF of field strength 5 V/cm during 30 min or 5 h depending on the parameters studied. In response to dcEF, the cells aligned perpendicular to the field by forming a leading edge with extended membrane protrusions towards the cathode. Using immunofluorescence and live cell imaging, we show that the cell membrane depolarized at the cathodal side. The microtubules spread into the direction of migration. Also, the microtubule organization center re-oriented into this direction. Concomitantly with the microtubules, actin filaments reorganized in an asymmetrical fashion mainly at the cathodal side. The Golgi apparatus, which is involved in many steps of actin synthesis, moved to the cathodal side. In the last 2 h of the 5 h experiment, microtubules positioned themselves at the rear (anodal side), like the nucleus. The averaged displacement of the whole cells under dcEF was 155% of control for 3 V/cm and 235% for 5 V/cm. The average speed increased by 142% and 243% respectively. Inside the cells mitochondria moved to the cathodal side, where the energy consuming producing processes take place. In this line, we measured an increase in ATP production and O2 consumption. Mitochondrial calcium was found more on the anodal side, at the site of the nucleus with its calcium delivering endoplasmic reticulum. In addition, oxymetry studies reveal an increased ATP synthesis by 115.2% and oxygen consumption by 113.3% 3 h after dcEF stimulation. An analysis of differentially expressed genes by RNA sequencing revealed an upregulation of genes involved in cellular movement, cell to cell and intracellular signaling, molecular transport, assembly and organization. The mechanisms found can enhance our understanding regarding the beneficial effects of EF treatment in retinal diseases.

2-Deoxy-D-glucose Alleviates Cancer Cachexia-Induced Muscle Wasting by Enhancing Ketone Metabolism and Inhibiting the Cori Cycle.

Cachexia is characterized by progressive weight loss accompanied by the loss of specific skeletal muscle and adipose tissue. Increased lactate production, either due to the Warburg effect from tumors or accelerated glycolysis effects from cachectic muscle, is the most dangerous factor for cancer cachexia. This study aimed to explore the efficiency of 2-deoxy-D-glucose (2-DG) in blocking Cori cycle activity and its therapeutic effect on cachexia-associated muscle wasting. A C26 adenocarcinoma xenograft model was used to study cancer cachectic metabolic derangements. Tumor-free lean mass, hindlimb muscle morphology, and fiber-type composition were measured after in vivo 2-DG administration. Activation of the ubiquitin-dependent proteasome pathway (UPS) and autophagic–lysosomal pathway (ALP) was further assessed. The cachectic skeletal muscles of tumor-bearing mice exhibited altered glucose and lipid metabolism, decreased carbohydrate utilization, and increased lipid β-oxidation. Significantly increased gluconeogenesis and decreased ketogenesis were observed in cachectic mouse livers. 2-DG significantly ameliorated cancer cachexia-associated muscle wasting and decreased cachectic-associated lean mass levels and fiber cross-sectional areas. 2-DG inhibited protein degradation-associated UPS and ALP, increased ketogenesis in the liver, and promoted ketone metabolism in skeletal muscle, thus enhancing mitochondrial bioenergetic capacity. 2-DG effectively prevents muscle wasting by increasing ATP synthesis efficiency via the ketone metabolic pathway and blocking the abnormal Cori cycle.

Yang-xin-xue keli exerts therapeutic effects via regulating mitochondrial homeostasis and function in doxorubicin-induced rat heart failure.

Background: Heart failure, especially chronic heart failure, is generally induced by the accumulation of reactive oxygen species (ROS), as well as the subsequent loss of mitochondrial permeability transition pore (mPTP) openings and pathological mitochondrial dysfunction. Herein, we explored the therapeutic effects of the Chinese medicine Yangxin Keli (YXXKL) on chronic heart failure and its underlying working mechanism. Methods: To mimic oxidative stress-induced chronic heart failure, a rat heart failure model was induced by the administration of DOX. Transthoracic echocardiography was performed to confirm the successful establishment of the heart failure model by observing significantly decreased cardiac function in the rats. Mitochondrial membrane potential, function, and ATP synthesis activity were measured after YXXKL was employed. Results The administration of YXXKL not only significantly improved cardiac function but also reversed the myocardium loss and fibrosis induced via DOX. Moreover, the administration of YXXKL also increased ATP synthesis and mitochondrial DNA mass in left ventricular tissues, which indicated that mitochondria may be a key target of YXXKL. Thus, we employed rat cardiomyocyte H9c2 and primary rat cardiac myocytes (RCMs) to induce oxidative stress-induced myocardial injury via DOX treatment. YXXKL-medicated serum promoted cell proliferation, which was inhibited by the addition of IC30 DOX, and the serum also inhibited cell apoptosis, which was promoted by the addition of IC50 DOX. YXKL-medicated serum was able to scavenge ROS and maintain the mitochondrial membrane potential as well as promote mitochondrial function, including the promotion of ATP synthesis, mitochondrial DNA mass, and transcriptional activity. Furthermore, we also observed that YXXKL-medicated serum inhibited DOX-induced autophagy/mitophagy by scavenging ROS. Conclusion: Taken together, we conclude that YXXKLI may exert therapeutic effects on oxidative stress-related heart failure via the regulation of mitochondria.

Differential hepatic mitochondrial function and gluconeogenic gene expression in 2 Holstein strains in a pasture-based system

The objective of this study was to assess hepatic ATP synthesis in Holstein cows of North American and New Zealand origins and the gluconeogenic pathway, one of the pathways with the highest ATP demands in the ruminant liver. Autumn-calving Holstein cows of New Zealand and North American origins were managed in a pasture-based system with supplementation of concentrate that represented approximately 33% of the predicted dry matter intake during 2017, 2018, and 2019, and hepatic biopsies were taken during mid-lactation at 174 ± 23 days in milk. Cows of both strains produced similar levels of solids-corrected milk, and no differences in body condition score were found. Plasma glucose concentrations were higher for cows of New Zealand versus North American origin. Hepatic mitochondrial function evaluated measuring oxygen consumption rates showed that mitochondrial parameters related to ATP synthesis and maximum respiratory rate were increased for cows of New Zealand compared with North American origin. However, hepatic gene expression of pyruvate carboxylase, phosphoenolpyruvate carboxykinase, and pyruvate dehydrogenase kinase was increased in North American compared with New Zealand cows. These results altogether suggest an increased activity of the tricarboxylic cycle in New Zealand cows, leading to increased ATP synthesis, whereas North American cows pull tricarboxylic cycle intermediates toward gluconeogenesis. The fact that this occurs during mid-lactation could account for the increased persistency of North American cows, especially in a pasture-based system. In addition, we observed an augmented mitochondrial density in New Zealand cows, which could be related to feed efficiency mechanisms. In sum, our results contribute to the elucidation of hepatic molecular mechanisms in dairy cows in production systems with higher inclusion of pastures.

Drosophila ZIP13 over-expression or transferrin1 RNAi influences the muscle degeneration of Pink1 RNAi by elevating iron levels in mitochondria.

Disruption of iron homeostasis in the brain of Parkinson's disease (PD) patients has been reported for many years, but the underlying mechanisms remain unclear. To investigate iron metabolism genes related to PTEN-induced kinase 1 (Pink1) and parkin (E3 ubiquitin ligase), two PD-associated proteins that function to coordinate mitochondrial turnover via induction of selective mitophagy, we conducted a genetic screen in Drosophila and found that altered expression of genes involved in iron metabolism, such as Drosophila ZIP13 (dZIP13) or transferrin1 (Tsf1), significantly influences the disease progression related to Pink1 but not parkin. Several phenotypes of Pink1 mutant and Pink1 RNAi but not parkin mutant were significantly rescued by over-expression (OE) of dZIP13 (dZIP13 OE) or silencing of Tsf1 (Tsf1 RNAi) in the flight muscles. The rescue effects of dZIP13 OE or Tsf1 RNAi were not exerted through mitochondrial disruption or mitophagy; instead, the iron levels in mitochondira were significantly increased, resulting in enhanced activities of enzymes participating in respiration and increased ATP synthesis. Consistently, the rescue effects of dZIP13 OE or Tsf1 RNAi on Pink1 RNAi can be inhibited by decreasing the iron levels in mitochondria through mitoferrin (dmfrn) RNAi. This study suggests that dZIP13, Tsf1, and dmfrn might act independently of parkin in a parallel pathway downstream of Pink1 by modulating respiration and indicates that manipulation of iron levels in mitochondria may provide a novel therapeutic strategy for PD associated with Pink1.

ATP Synthase K+- and H+-Fluxes Drive ATP Synthesis and Enable Mitochondrial K+-"Uniporter" Function: I. Characterization of Ion Fluxes.

ATP synthase (F1Fo) synthesizes daily our body's weight in ATP, whose production-rate can be transiently increased several-fold to meet changes in energy utilization. Using purified mammalian F1Fo-reconstituted proteoliposomes and isolated mitochondria, we show F1Fo can utilize both ΔΨm-driven H+- and K+-transport to synthesize ATP under physiological pH=7.2 and K+ = 140mEq/L conditions. Purely K+-driven ATP synthesis from single F1Fo molecules measured by bioluminescence photon detection could be directly demonstrated along with simultaneous measurements of unitary K+ currents by voltage clamp, both blocked by specific Fo inhibitors. In the presence of K+, compared to osmotically-matched conditions in which this cation is absent, isolated mitochondria display 3.5-fold higher rates of ATP synthesis, at the expense of 2.6-fold higher rates of oxygen consumption, these fluxes being driven by a 2.7:1 K+: H+ stoichiometry. The excellent agreement between the functional data obtained from purified F1Fo single molecule experiments and ATP synthase studied in the intact mitochondrion under unaltered OxPhos coupling by K+ presence, is entirely consistent with K+ transport through the ATP synthase driving the observed increase in ATP synthesis. Thus, both K+ (harnessing ΔΨm) and H+ (harnessing its chemical potential energy, ΔμH) drive ATP generation during normal physiology.