Activities Of Glycolytic Enzymes Research Articles

Andrographis paniculata improves glucose regulation by enhancing insulin sensitivity and upregulating GLUT 4 expression in Wistar rats.

Although the hypoglycaemic effect of Andrographis paniculata (Burm.f.) Nees [Acanthaceae] has been documented, reports on its effect in an apparently healthy state are limited. This study investigated whether or not A. paniculata exerts hypoglycaemic effect in a non-diabetic state. It also explored the impact of A. paniculata on glycolytic enzymes and GLUT 4 protein expression, as a possible mode of action. Twenty male Wistar rats were randomly assigned into two groups (n = 10 rats/group). The control rats were vehicle-treated (0.5 ml of distilled water), while the A. paniculata-treated rats had 500 mg/kg of A. paniculata per os once daily for 35 days. A. paniculata treatment led to improved insulin sensitivity evidenced by increased HOMA-β (88.08 ± 2.13 vs. 120.80 ± 1.52, p < 0.0001), HOMA-S (283.60 ± 8.82 vs. 300.50 ± 9.30, p = 0.0189), and reduced TyG index (4.22 ± 0.04 vs. 3.95 ± 0.07, p < 0.0002) and HOMA-IR (0.32 ± 0.01 vs. 0.25 ± 0.01, p < 0.0001) when compared with the control. It also improved glucose regulation as depicted by reduced fasting blood glucose (3.77 ± 0.10 vs. 3.24 ± 0.11, p < 0.0001) and glycated hemoglobin (HbA1c; 7.69 ± 1.15 vs. 5.95 ± 0.82, p = 0.0245), and atherogenic dyslipidaemia, including AIP (-0.12 ± 0.03 vs. -0.26 ± 0.03, p < 0.0001) and CRI-I (2.70 ± 0.29 vs. 1.84 ± 0.27, p < 0.0001). These findings were accompanied by enhanced hepatic and muscular redox state, increased activities of glycolytic enzymes, upregulated GLUT 4 (0.80 ± 0.27 vs. 6.20 ± 0.84, p < 0.0001), and increased circulating nitric oxide (5.45 ± 0.24 vs. 6.79 ± 0.33, p = 0.0002). A. paniculata exerts positive effect on glucose metabolism and utilization by improving insulin sensitivity and upregulating the activities of glycolytic enzymes and GLUT 4 protein expression. This implies that A. paniculata may be beneficial in preventing insulin resistance and incident diabetes. Nonetheless, it should be used with caution to prevent hypoglycaemia in a non-diabetic state.

Activation patterns of intracellular signaling pathways in cardiac hypertrophy induced by different exercise modes in rats

Abstract Introduction Cardiac remodeling and hypertrophy cause as adaptive responses to physiological and pathological stimuli. Physiological cardiac hypertrophy is characterized by normal or enhanced cardiac function and myocardial metabolism, and induces concentric and eccentric hypertrophy by different exercise modes, without cardiac dysfunction and fibrosis. Each formative mechanism of cardiac hypertrophy is regulated by distinct and/or similar cellular signaling pathways. Activation of cardiac intracellular signaling pathway of phosphoinositide 3- kinase (PI3K) is involved in an underlying mechanism of developed eccentric cardiac hypertrophy by aerobic exercise training (AT). However, the activation patterns of intracellular signaling pathways of physiological cardiac hypertrophy by different exercise modes remain unclear. Purpose The purpose of this study was to investigate the activation patterns of intracellular signaling pathways in cardiac hypertrophy induced by different exercise modes, including AT, resistance training (RT), and high intensity interval training (HIIT). Methods Forty male 10-week-old Sprague-Dawley (SD) rats were divided into four groups; sedentary control (Con, n=10), AT (treadmill running, 60 min at 30 m/min, 5 days/wk for 8 wk, n=10), RT (ladder climbing, 8-10 sets/day, 3 d/wk for 8 wk, n=10), HIIT (14 repeats of 20-s swimming session with 10-s pause between sessions, 4 d/wk for 6 wk from 12-wk-old, n=10) groups. As a cardiac hypertrophic intracellular signaling pathways, PI3K protein expression level and mTOR and MAPK (ERK1/2, JNK1/2 and p38) phosphorylation levels in rat hearts were measured by Western blotting analysis. Results The hearts of rats in each training group developed cardiac hypertrophy. Moreover, the enzyme activity of oxidative phosphorylation in the skeletal muscle was promoted in the AT group, the oxidative phosphorylation and glycolytic enzyme activities were promoted in the HIIT group, and muscle hypertrophy occurred in the RT group. Levels of PI3K protein expression and mTOR phosphorylation in the heart were significantly higher in the AT, RT, and HIIT groups as compared to the Con group (each p&amp;lt;0.05). Additionally, p38 phosphorylation level in the heart was significantly higher in the RT group as compared to the Con, AT, and HIIT groups (each p&amp;lt;0.05). Furthermore, p44 ERK phosphorylation level in the heart of the RT group was significantly higher than that in the AT and HIIT groups (each p&amp;lt;0.05), but p42 ERK phosphorylation level did not differ among four groups. JNK1/2 (p46/p54) phosphorylation level in the heart was significantly higher in the RT group as compared to the Con group (p&amp;lt;0.05). Conclusion These findings suggest that the activation of PI3K-mTOR signaling pathway in the heart may be involved in the development of AT, RT and HIIT-induced cardiac hypertrophy, and the MAPK signaling activation may affect the development of cardiac hypertrophy by RT.

Taurine reduces glycolysis of pig skeletal muscle by inhibiting HIF-1α signaling.

The aim of this study was to investigate the effect of taurine on skeletal muscle glycolysis in pigs. The results showed that dietary supplementation of taurine significantly reduced the activities of hexokinase (HK), phosphofructose kinase (PFK), and pyruvate kinase (PK) in finishing pigs. Meanwhile, taurine reduced the protein and mRNA expression levels of hypoxia inducible factor 1α (HIF-1α) and the mRNA expression of glycolytic enzyme related genes (such as HK type II, HK Ⅱ; pyruvate kinase M2, PKM2; lactate dehydrogenase A, LDHA). In addition, taurine reduced the expression of HIF-1α, lactate content, and the expression of glycolysis related genes in porcine myotubes. These results suggest that taurine may regulate glycolysis in skeletal muscle of finishing pigs through the HIF-1α signaling pathway. To further investigate the mechanism by which taurine affects skeletal glycolysis, HIF-1α activator dimethyloxalyl glycine (DMOG) was used to treat porcine myotubes, our results showed that DMOG significantly increased the protein and mRNA expression levels of HIF-1α, lactate content, and glycolytic enzyme (HK, PFK, PK, and LDH) activity, but taurine treatment significantly inhibited this effect. Taken together, these results of in vivo and in vitro experiments revealed that taurine reduces skeletal muscle glycolysis by inhibiting HIF-1α signaling.

Investigation of nanoparticles present in biochemic tissue salt Kalium phosphoricum in different potencies

BackgroundBiochemic tissue salts are defined as essential inorganic salts needed to maintain homoeostasis within living tissue. Kali phosphoricum is one of the twelve biochemic tissue salts. Nanomedicine is an expanding field, in which nanoparticles play an integral part and are known to exist in the natural world and can also be manufactured by scientists. This study sought to determine whether Kali phos included nanoparticles and whether may help to mitigate brain problems. Material and methodTo investigate whether potassium phosphate nanoparticles were present in Kali phos, ultraviolet-visible spectroscopy and Fourier transform infrared spectroscopy were used. To analyze the biochemical parameters, the homogenate of brain was incubated with lactose powder (control group), different potencies of Kali phos and K2HPO4. 25 % homogenate of normal brain tissue was made with the help of ice cold 0.02 M Tris-Cl (pH 7.4) buffer. Different antioxidant enzymes and glycolytic enzyme activities were measured. ResultsIt may be concluded from this investigation, utilizing these chosen potencies, that the biochemic tissue salt Kali phos does contain nanoparticles of potassium phosphate, adding to the development of the nanomedicine field. Lower potency remedies were more effective in modulating the level of antioxidant and glycolytic enzymes. ConclusionAlthough there is clearly a body of scientific evidence, mainstream medicine claims that there is simply an inadequate amount of such evidence. These results may expand the range of use and applications of biochemic tissue salts, lay the groundwork for the creation of empirical homoeopathic evidence, and bring innovative research avenues.

The enhancing effects of selenomethionine on harmine in attenuating pathological cardiac hypertrophy via glycolysis metabolism.

Pathological cardiac hypertrophy, a common feature in various cardiovascular diseases, can be more effectively managed through combination therapies using natural compounds. Harmine, a β-carboline alkaloid found in plants, possesses numerous pharmacological functions, including alleviating cardiac hypertrophy. Similarly, Selenomethionine (SE), a primary organic selenium source, has been shown to mitigate cardiac autophagy and alleviate injury. To explores the therapeutic potential of combining Harmine with SE to treat cardiac hypertrophy. The synergistic effects of SE and harmine against cardiac hypertrophy were assessed invitro with angiotensin II (AngII)-induced hypertrophy and invivo using a Myh6R404Q mouse model. Co-administration of SE and harmine significantly reduced hypertrophy-related markers, outperforming monotherapies. Transcriptomic and metabolic profiling revealed substantial alterations in key metabolic and signalling pathways, particularly those involved in energy metabolism. Notably, the combination therapy led to a marked reduction in the activity of key glycolytic enzymes. Importantly, the addition of the glycolysis inhibitor 2-deoxy-D-glucose (2-DG) did not further potentiate these effects, suggesting that the antihypertrophic action is predominantly mediated through glycolytic inhibition. These findings highlight the potential of SE and harmine as a promising combination therapy for the treatment of cardiac hypertrophy.

Dynamic changes of protein lactylation and their correlations with the glycolytic process during the postmortem acidification of broiler breast

This experiment aimed to reveal the dynamic changes of protein post-translational lactylation modifications and their correlations with the glycolytic process in broiler breast muscle within 48 h of postmortem acidification. The experiment involved 12 male AA broilers, 42 days old, with similar body weights (2.8 ± 0.05 kg). The breast fillets (Pectoralis major) were collected after slaughter, and samples were taken at various time points: 0, 15 min, 30 min, 45 min, 60 min, 2 h, 4 h, 6 h, 8 h, 12 h, 18 h, 24 h, 36 h, and 48 h postmortem. The results showed that the rate of glycogen decline in the muscle was highest at 45 min postmortem, and glycogen levels tended to stabilize at 8 h postmortem. The lactate content in the breast reached its highest level at 4 h postmortem and began to decrease, stabilizing at 24 h postmortem. Additionally, the glycolytic potential increased gradually in the first 4 h postmortem, decreased rapidly from 4 to 8 h. Similarly, lactylation modification levels were highest at 8 h postmortem, but stabilized at 12 h postmortem. During this process, the protein expression of the enzymatic lactylation modifier p300 showed no significant difference, while the content of the nonenzymatic lactylation substrate lactoylglutathione significantly decreased at 8 h and 24 h postmortem. Correlation analysis found that lactylation levels were negatively correlated with glycogen content, glucose content, glycolytic potential, and pH value, while positively correlated with lactate content. Besides, there was a positive correlation between lactylation levels and the protein expression of hexokinase, phosphoglycerate kinase 2, phosphoglucomutase 1, and triosephosphate isomerase. Additionally, lactylation levels were positively correlated with the activities of lactate dehydrogenase and phosphofructokinase. In summary, our experiment elucidated the dynamic changes in the entire glycolytic pathway in broiler pectoral muscle during acidification. During this process, lactylation modifications may participate in the glycolysis process by regulating the protein expression and activity of glycolytic enzymes.

Transcriptional regulation of multi-tissue mRNA expression by L-arabinose mitigates metabolic disorders in leptin receptor-deficient mice

L-arabinose, a sugar substitute, exhibits anti-diabetic effects due to its lower caloric content than conventional sugar. However, the comprehensive molecular mechanisms underlying its organ-to-organ interactions remain elusive in transgenic mouse models. Therefore, we investigated these anti-diabetic effects using mRNA sequencing analysis across multiple tissues. We used leptin receptor-deficient mice subjected to a normal diet with sucrose (SUC), SUC supplemented with erythritol (ERY), and SUC supplemented with L-arabinose (ARA) for 16 weeks. Prolonged supplementation with L-arabinose significantly lowered fasting blood glucose and HOMA-IR levels, improved glucose tolerance, and markedly reduced body fat in the leptin receptor-deficient mice without affecting food and energy intake. The ARA group exhibited decreased activities of gluconeogenic enzymes (PEPCK, G6Pase) and increased glycolytic enzyme activity, signifying enhanced insulin sensitivity. Additionally, significant alterations in gene expression related to fatty acid metabolism and insulin resistance were observed, including a notable increase in the transcription of genes essential for fatty acid oxidation. L-arabinose supplementation also led to improved myogenesis and a reduction in chronic inflammation, indicating potential efficacy in mitigating diabetic sarcopenia. Overall, this study positions L-arabinose supplementation as a promising therapeutic strategy for managing insulin resistance and its associated complications, meriting further investigation into its role in diabetes management.

Effects of kaempherol-3-rhamnoside on metabolic enzymes and AMPK in the liver tissue of STZ-induced diabetes in mice

Diabetes mellitus (DM) is a chronic metabolic disorder characterized by persistent hyperglycemia. It involves disturbances in carbohydrate, fat, and protein metabolism due to defects in insulin secretion, insulin action, or both. Novel therapeutic approaches are continuously being explored to enhance metabolic control and prevent complications associated with the disease. This study investigates the therapeutic potential of kaempherol-3-rhamnoside, a flavonoid, in managing diabetes by modulating the AMP-activated protein kinase (AMPK) pathway and improving metabolic enzyme activities in streptozotocin (STZ) -induced diabetic mice. Diabetic mice were treated with varying doses of kaempherol-3-rhamnoside and/or insulin over a 28-day period. Glycolytic and gluconeogenesis enzyme activities in the liver, fasting blood glucose levels, serum insulin levels, lipid profiles and oxidative stress markers were assessed. Treatment with kaempherol-3-rhamnoside significantly improved glycolytic enzyme activities, reduced fasting blood glucose, and enhanced insulin levels compared to diabetic controls. The compound also normalized lipid profiles and reduced oxidative stress in the liver, suggesting its potential in reversing diabetic dyslipidemia and oxidative damage. Furthermore, kaempherol-3-rhamnoside activated the AMPK pathway, indicating a mechanism through which it could exert its effects. Kaempherol-3-rhamnoside exhibits promising antidiabetic properties, potentially through AMPK pathway activation and metabolic enzyme modulation. These findings support its potential use as an adjunct therapy for diabetes management. Further clinical studies are warranted to validate these results in human subjects.

Gamma-Aminobutyric Acid (GABA) Avoids Deterioration of Transport Water Quality, Regulates Plasma Biochemical Indices, Energy Metabolism, and Antioxidant Capacity of Tawny Puffer (Takifugui flavidus) under Transport Stress.

Live fish transportation is crucial for managing aquaculture but can pose health risks to fish due to stressors encountered during transportation. Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter that plays a crucial role in the central nervous system and is considered to exhibit anti-stress effects. This study aims to investigate the effects of GABA on the transport water quality, plasma biochemical indices, energy metabolism, and antioxidant capacity of tawny puffer (Takifugu flavidus) under transport stress. Tawny puffer were pretreated by immersing in aquariums containing GABA (final concentrations at 0, 5, 50, and 150 mg/L) seawater for 3 days; then, simulated transport was conducted using oxygen-filled polyethylene bags containing the same concentration of GABA seawater as the pretreatment period. Water samples, plasma, and liver were collected after 0, 6, and 12 h of transport. The results revealed that with the prolongation of transportation time, the control group's water quality deteriorated, stress-related plasma biochemical indices increased, glycolytic substrate contents decreased, glycolytic enzyme activities and product contents increased, and aerobic metabolic enzyme activities exhibited initial increases followed by declines, ATPase activities decreased, antioxidant enzyme activities decreased, and the lipid peroxidation marker contents increased. It is noteworthy that GABA treatment could avoid water quality deterioration during transportation, inhibit an elevation in stress-related biochemical indicators, regulate energy metabolism, and reduce oxidative damage in tawny puffer, especially at 50 and 150 mg/L concentrations. In summary, GABA treatment can effectively alleviate the transport stress of tawny puffer.

Titanium dioxide nanoparticles induce energy perturbation by stimulating glycolytic metabolic profile in rats

The safety of titanium dioxide nanoparticles (TiO2-NPs) remains uncertain due to a scarcity of data regarding its absorption, distribution, elimination, and potential adverse effects following oral exposure. As emerging evidence suggests perturbations in energy metabolism play a pivotal role in the toxicity induced by various toxicants, this investigation aimed to assess the effect of TiO2-NPs on the activities of specific glycolytic enzymes in rats. In this study, seventy-two (72) male Wistar rats (200 ± 20g) were divided into 12 groups, each consisting of 6 animals. The rats were orally exposed to TiO2-NPs (8-12nm) at doses of 50, 150, and 250 mg/kg body weight (BW) for durations of 4, 8, and 12 weeks. The control groups received distilled water. The results showed that, except for the 150 mg/kg BW dose of 12 weeks, TiO2-NPs exposure led to an up-regulation in hexokinase activity in lymphocytes, plasma, erythrocytes, and the liver. Hepatic and lymphocyte aldolase activities were also up-regulated, except at 8 and 12 weeks for the 50 and 150 mg/kg BW doses, where slight decreases were observed. Plasma aldolase increased, except at 12 weeks for 150 mg/kg BW dose, while erythrocyte aldolase increased only during the 4 and 8-week exposure but decreased throughout the 12-week exposure. Notably, compared to erythrocyte lactate dehydrogenase activity, which decreased, a consistent pattern observed in lymphocytes, plasma, and hepatic enzymes was a down-regulation at 8 and 12 weeks for the 50 and 150 mg/kg BW doses of TiO2-NPs. In other instances, and time intervals, lactate dehydrogenase was up-regulated. The data from this study underscores that exposure to TiO2-NPs can disrupt the glycolytic pathway of energy metabolism, particularly during the initial 4 weeks of exposure. These perturbations are characterized by increased glycolytic enzymes activity in the lymphocytes, plasma, and the liver.

Effects of endurance training under calorie restriction on energy substrate metabolism in mouse skeletal muscle and liver

We investigated whether calorie restriction (CR) enhances metabolic adaptations to endurance training (ET). Ten-week-old male Institute of Cancer Research (ICR) mice were fed ad libitum or subjected to 30% CR. The mice were subdivided into sedentary and ET groups. The ET group performed treadmill running (20–25 m/min, 30 min, 5 days/week) for 5 weeks. We found that CR decreased glycolytic enzyme activity and monocarboxylate transporter (MCT) 4 protein content, while enhancing glucose transporter 4 protein content in the plantaris and soleus muscles. Although ET and CR individually increased citrate synthase activity in the plantaris muscle, the ET-induced increase in respiratory chain complex I protein content was counteracted by CR. In the soleus muscle, mitochondrial enzyme activity and protein levels were increased by ET, but decreased by CR. It has been suggested that CR partially interferes with skeletal muscle adaptation to ET.

Unravelling the metabolic rewiring in the context of doxorubicin-induced cardiotoxicity: Fuel preference changes from fatty acids to glucose oxidation

Doxorubicin (DOX) is a highly effective chemotherapeutic agent whose clinical use is hindered by the onset of cardiotoxic effects, resulting in reduced ejection fraction within the first year from treatment initiation. Recently it has been demonstrated that DOX accumulates within mitochondria, leading to disruption of metabolic processes and energetic imbalance. We previously described that phosphoinositide 3-kinase γ (PI3Kγ) contributes to DOX-induced cardiotoxicity, causing autophagy inhibition and accumulation of damaged mitochondria. Here we intend to describe the maladaptive metabolic rewiring occurring in DOX-treated hearts and the contribution of PI3Kγ signalling to this process. Metabolomic analysis of DOX-treated WT hearts revealed an accumulation of TCA cycle metabolites due to a cycle slowdown, with reduced levels of pyruvate, unchanged abundance of lactate and increased Acetyl-CoA production. Moreover, the activity of glycolytic enzymes was upregulated, and fatty acid oxidation downregulated, after DOX, indicative of increased glucose oxidation. In agreement, oxygen consumption was increased in after pyruvate supplementation, with the formation of cytotoxic ROS rather than energy production. These metabolic changes were fully prevented in KD hearts. Interestingly, they failed to increase glucose oxidation in response to DOX even with autophagy inhibition, indicating that PI3Kγ likely controls the fuel preference after DOX through an autophagy-independent mechanism. In vitro experiments showed that inhibition of PI3Kγ inhibits pyruvate dehydrogenase (PDH), the key enzyme of Randle cycle regulating the switch from fatty acids to glucose usage, while decreasing DOX-induced mobilization of GLUT-4-carrying vesicles to the plasma membrane and limiting the ensuing glucose uptake. These results demonstrate that PI3Kγ promotes a maladaptive metabolic rewiring in DOX-treated hearts, through a two-pronged mechanism controlling PDH activation and GLUT-4-mediated glucose uptake.

Erjingpill bionic cerebrospinal fluid alleviates LPS-induced inflammatory response in BV2 cells by inhibiting glycolysis via mTOR

Ethnopharmacological relevanceErjingpill, a well-known prescription documented in the classic Chinese medical text “Shengji Zonglu,” has been proven to have effective alleviating effects on neuroinflammation in Alzheimer's disease (AD). Although the alterations in microglial cell glycolysis are known to play a crucial role in the development of neuroinflammation, it remains unclear whether the anti-neuroinflammatory effects of Erjingpill are associated with its impact on microglial cell glycolysis. Aim of the studyThis study aims to determine whether Erjingpill exerts anti-neuroinflammatory effects by influencing microglial cell glycolysis. Materials and methodsFirstly, Erjingpill decoction was prepared into an Erjingpill bionic cerebrospinal fluid (EBCF) through a process of in vitro intestinal absorption, hepatocyte incubation, and blood-brain barrier (BBB) transcytosis. Subsequently, UPLC/Q-TOF-MS/MS technology was used to analyze the compounds in Erjingpill and EBCF. Next, an in vitro neuroinflammation model was established by LPS-induced BV2 cells. The impact of EBCF on BV2 cell proliferation activity was evaluated using the CCK-8 assay, while the NO release was assessed using the Griess assay. Additionally, mRNA levels of pro-inflammatory factors (IL-1β, IL-6, TNF-α, and COX-2), anti-inflammatory factors (IL-10, IL-4, Arg-1, and TGF-β), M1 microglial markers (iNOS, CD86), M2 microglial markers (CD36, CD206), and glycolytic enzymes (HK2, GLUT1, PKM, and LDHA) were measured using qPCR. Furthermore, protein expression of microglial activation marker Iba-1, M1 marker iNOS, and M2 marker CD206 were identified through immunofluorescence, while concentrations of pro-inflammatory cytokines IL-1β and TNF-α were measured using ELISA. Enzymatic activity of glycolytic enzymes (HK, PK, and LDH) was assessed using assay kits, and the protein levels of pro-inflammatory factors (IL-1β, iNOS, and COX-2), anti-inflammatory factors (IL-10 and Arg-1), and key glycolytic proteins GLUT1 and PI3K/AKT/mTOR were detected by Western blot. ResultsThrough the analysis of Erjingpill and EBCF, 144 compounds were identified in Erjingpill and 40 compounds were identified in EBCF. The results demonstrated that EBCF effectively inhibited the elevation of inflammatory factors and glycolysis levels in LPS-induced BV2 cells, promoted polarization of M1 microglial cells towards the M2 phenotype, and suppressed the PI3K/AKT/mTOR inflammatory pathway. Moreover, EBCF alleviated LPS-induced BV2 cell inflammatory response by modulating mTOR to inhibit glycolysis. ConclusionsEBCF exhibits significant anti-neuroinflammatory effects, likely attributed to its modulation of mTOR to inhibit microglial cell glycolysis. This study furnishes experimental evidence supporting the clinical utilization of Erjingpill for preventing and treating AD.

A novel polysaccharide of Undaria pinnatifida: Structural characterization, carboxymethylation and hypoglycemic activity in vivo

A new polysaccharide (UPP) was isolated and purified from Undaria pinnatifida with a low molecular weight of 8.34 kDa. The UPP was modified to obtain carboxymethylated polysaccharide (CM-UPP). UPP and CM-UPP were characterized by FT-IR, Ion chromatography, Congo red, DSC, SEM and NMR, and their hypoglycemic activity in vivo was investigated using the STZ-induced diabetes mice model. UPP mainly contained Ara, Gal, Glc and Man at a molar ratio of 0.18: 0.13: 2.06: 1, and CM-UPP added two alduronic acids including GalA and GlcA. CM-UPP had been prepared successfully and the carboxymethylation reaction might occur partially at the C-2 and C-4 position. There were no triple helix structures in both UPP and CM-UPP. In vivo hypoglycemic activity studies showed that both UPP and CM-UPP could alleviate symptoms of high blood glucose, improve blood lipid level, oxidative stress state and liver glycolytic enzyme activity in diabetic mice. Under the same dose, CM-UPP showed a more significant effect than UPP. These results indicated that carboxymethylation was an effective way to enhance the hypoglycemic activitiy of polysaccharide. UPP and CM-UPP could be potential therapeutic agents of T2DM.

Exploring the mechanisms of metabolic adaptations to cardiotoxic doxorubicin

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Leducq Foundation Background Doxorubicin (DOX) is an anthracycline chemotherapeutic agent whose clinical application is hindered by the emergence of early and late cardiotoxic effects. Recent findings demonstrated that DOX damages cardiac mitochondria, with subsequent metabolic perturbation and energetic imbalance. We previously observed that phosphoinositide 3-kinase γ (PI3Kγ) contributes to DOX-induced cardiotoxicity, mediating mitophagy inhibition and accumulation of damaged mitochondria into cardiac cells. Objective Here we intend to describe the cardiotoxic metabolic phenotype of DOX-treated hearts, unravelling the contribution of PI3Kγ signalling to this process. Methods Wild-type (WT) and knock-in mice expressing a kinase-inactive PI3Kγ (kinase-dead; KD) were treated with DOX at day 0, 7 and 14 (cumulative dose 12 mg/kg). To explore the contribution of PI3Kγ on the early cardiac metabolic rewiring, metabolomic analysis, mitochondrial respiration capacity and glycolytic enzymes activity were evaluated at day 3. To investigate the role of autophagy, mice were infected with an adeno-associated virus 9 (AAV9) carrying a vector expressing a short-hairpin RNA against ATG7 (ATG7sh). To test the role of PI3Kγ in glycolysis regulation, glucose uptake and plasma membrane exposure of GLUT-4 were measured in neonatal mouse cardiomyocytes with DOX acute treatment (1µM for 3h). To evaluate the contribution of different substrates to oxygen consumption, OROBOROS analysis were performed on myocardial slices from mice sacrificed at day 3 and 42. Results DOX-treated cardiomyocytes exhibited a metabolic phenotype characterized by glucose as the primary energy substrate, with increased uptake and augmented glycolytic enzymes activity. Metabolomic analysis of DOX-treated hearts indicated diminished pyruvate levels, the glycolysis end-product, unaltered lactate but increased Acetyl-CoA quantity, suggesting enhanced glucose processing for the TCA cycle. Accordingly, oxygen consumption after pyruvate supplementation significantly increased in DOX-treated condition, resulting in the generation of cytotoxic ROS rather than energy production. This was mainly due to DOX-induced mitochondrial damage, with impaired fatty acid oxidation and electron transport chain activity, resulting in TCA cycle slow-down, with accumulation of cardiotoxic glucose-derived intermediates. These metabolic alterations were completely prevented in KD hearts. In vitro experiments demonstrated that inhibiting PI3Kγ reduced the activity of pyruvate dehydrogenase (PDH), the key enzyme of Randle cycle, regulating the switch from fatty acids to glucose usage, while decreasing DOX-induced mobilization of GLUT-4-carrying vesicles to the plasma membrane, limiting subsequent glucose uptake. Conclusion These results demonstrate that DOX promotes an early metabolic rewiring with PI3Kγ-dependent increased glucose uptake and modulation of the Randle cycle towards augmented glucose utilization.

Vibration Emissions Reduce Boar Sperm Quality via Disrupting Its Metabolism.

Artificial insemination (AI) with liquid-preserved semen has recently become common in pig breeding. The semen doses are produced in a centralized manner at the boar stud and then subsequently distributed and transported to sow farms. However, vibration emissions during transportation by logistic vehicles may adversely affect the quality of boar sperm. Therefore, this study aimed to explore the impact of vibration-induced emissions on sperm quality and function under simulated transportation conditions. Each time, ejaculates from all 15 boars were collected and then pooled together to minimize individual variations, and the sample was split using an extender for dilution. Different rotational speeds (0 rpm, 80 rpm, 140 rpm, 200 rpm) were utilized to simulate varying intensities of vibration exposure using an orbital shaker, considering different transportation times (0 h, 3 h, and 6 h). Subsequently, evaluations were conducted regarding sperm motility, plasma membrane integrity, acrosome integrity, mitochondrial function, adenosine triphosphate (ATP) levels, mitochondrial reactive oxygen species (ROS) levels, pH, glycolytic pathway enzyme activities, and capacitation following exposure to vibration emissions. Both vibration time and intensity impact sperm motility, plasma membrane integrity, and acrosomal integrity. Vibration exposure significantly reduced sperm ATP levels, mitochondrial membrane potential, and the levels of mitochondria-encoded proteins (MT-ND1, MT-ND6) (p < 0.05). After vibration emission treatment, the pH value and mitochondrial ROS levels significantly increased (p < 0.05). Inhibition of sperm glycolysis was observed, with reduced activities of hexokinase (HK), pyruvate kinase (PK), and lactate dehydrogenase (LDH), along with decreased lactate levels (p < 0.05). Additionally, sperm tyrosine phosphorylation levels were significantly reduced by vibration emissions compared to the control group (p < 0.05). After the vibration emission treatment, the number of sperm bound to each square millimeter of oviduct explants decreased significantly compared to the control group (p < 0.05). Similarly, compared to the control group, using semen subjected to vibration stress for AI results in significantly reduced pregnancy rates, total born litter size, live-born litter size, and healthy born litter size (p < 0.05).

An integrated analysis of transcriptome and metabolome to reveal the effects of temperature stress on energy metabolism and physiological responses in Schizothorax wangchiachii muscles

The unique hydrological situation of Jinsha River and the construction and operation of large hydropower stations may cause resident Schizothorax wangchiachii to experience acute changes in water temperature. To reveal the response mechanisms of S. wangchiachii to high and low temperature stress, we conducted a stress experiment. Compared with the control group, the activity of antioxidant enzymes (SOD\\CAT) increased first and then decreased at high temperature, while MDA activity in the low temperature group continued to increase slowly. The activities of glycolytic enzymes were increased initially and then decreased including HK and PFK, but PK activity continued to increase throughout the stress period. Transcriptome sequencing showed that a large number of genes in muscle tissues were differentially expressed after high and low temperature stress, and the main enriched pathways included glycosaminoglycan biosynthesis, lysine degradation, glycerolipid metabolism, the PPAR signaling pathway, and the adipocytokine signaling pathway. Significant metabolic pathways were identified as enriched according to the metabolic differences,such as glycerophospholipid metabolism, qRT-PCR was used to verify gene expression. The results suggested that both high temperature and low temperature stress induced physiological responses in S. wangchiachii that maintained homeostasis by regulating glucolipid metabolism and amino acid degradation. This study revealed the response mechanisms of S. wangchiachii to high and low temperature stress, information that may serve as a reference for the study of responses in other fish to environmental changes in the upper reaches of the Yangtze River or where they are displaced by hydropower station construction.

Regulation of carbohydrate metabolism and insulin secretion in diabetic rats following treatment with Hypericum perforatum L. hairy root aqueous methanol extract

Hairy root (HR) cultures of Hypericum perforatum L. have shown promise in controlling hyperglycemia, regulating blood lipid and enzyme profiles, and improving metabolic function in vivo. These benefits are mainly attributed to the phenolic acids, flavonoids, and xanthones present in HR extracts. However, the specific mechanism underlying these effects remains unclear. This study was performed to elucidate the biochemical and molecular mechanisms driving HR the antihyperglycemic and antidiabetic effects of HR extracts. HR extract (200 mg/kg body weight) was administered daily for 14 days to healthy rats and rats with streptozotocin-induced diabetes, with glibenclamide serving as a positive control. The phenolic composition of the HR extracts was confirmed through high-performance liquid chromatography/diode array detection/electrospray ionization mass spectrometry (HPLC/DAD/ESI-MSn ) analysis. The results showed that HR extract treatment increased the plasma insulin level and pancreatic poly (adenosine diphosphate-ribose) polymerase (PARP) activity in diabetic rats, thus normalizing blood glucose levels. Additionally, it reduced the activity of gluconeogenic enzymes, increased the activity of glycolytic enzymes, and normalized the glycogen content in the liver. HR extract-treated rats also exhibited increased hepatic adenosine monophosphate-activated protein kinase (AMPK) mRNA expression and a decreased protein kinase Cε (PKCε) concentration. In conclusion, HR extract demonstrated insulinotropic effects and effectively regulated hepatic carbohydrate metabolism in diabetic rats by modulating AMPK expression and the PKCε concentration. These findings suggest the potential use of HR extract as an herbal medicine for diabetes treatment and a source of antidiabetic drug development.

Integrated multiple-omics reveals the regulatory mechanism underlying the effects of homologous Bacillus tequilensis (GCB-3) on growth performance of grass carp (Ctenopharyngodon idellus)

The purpose of this study was to investigate the regulatory mechanism of Bacillus tequilensis (GCB-3) in improving the growth performance of grass carp by microbiome and targeted metabolomics analysis. Fish were fed with different amounts of GCB-3 including B0 (0 CFU/g), B6 (1×106 CFU/g), B7 (1×107 CFU/g), B8 (1×108 CFU/g), and B9 (1×109 CFU/g) for 8 weeks. The results indicate that with the increase of dietary GCB-3 concentration, grass carp showed a significant linear trend in growth performance, and appetite factors showed a significant linear and quadratic trend, the growth performance and appetite-promoting factors in the B8 group reach their maximum value in the B8 group. Microbiome analysis found that Proteobacteria and Actinobacteria were the most abundant phylum in the gut microbiota of grass carp. The functional potential predicted that GCB-3 affected the synthesis and degradation of carbohydrates, amino acids, fatty acids and lipids. It found that GCB-3 also affected the tricarboxylic acid (TCA) cycle VII (acetate-producers) pathway. The results of targeted metabolomics showed a significant linear and quadratic increase in intestinal acetate with GCB-3 concentration and a maximum in the B8 group. The results of the correlation analysis showed a significant positive correlation between Actinobacteria abundance and acetic acid content, and also between TCA cycle VII (acetate-producers) pathway abundance and Actinobacteria abundance and acetic acid content. In B8 group, grass carp showed a faster regulation speed of blood glucose levels after glucose injection, and the GLP-1 content remained stable. The activities of glycolytic enzymes, lipolytic enzymes, protein metabolism enzymes, and their related mRNA expression levels in grass carp showed a linear or quadratic increasing trend. However, the expression levels of gluconeogenic enzymes and fatty acid synthesis enzyme related mRNA showed an opposite trend. In summary, the addition of 1×108 CFU/g GCB-3 in grass carp feed can improve the abundance of dominant bacterial phyla in the intestine, especially Actinobacteria, increase the concentration of intestinal acetate, provide substrate for the TCA cycle VII (acetate-producers) pathway, thereby regulating the nutrient metabolism of grass carp and ultimately promoting growth.

Better maintenance of enzymatic capacity and higher levels of substrate transporter proteins in skeletal muscle of aging female mice.

This study investigated sex-specific differences in high-energy phosphate, glycolytic, and mitochondrial enzyme activities and also metabolite transporter protein levels in the skeletal muscles of adult (5 months old), middle-aged (12 months old), and advanced-aged (24 months old) mice. While gastrocnemius glycogen content increased with age regardless of sex, gastrocnemius triglyceride levels increased only in advanced-aged female mice. Aging decreased creatine kinase and adenylate kinase activities in the plantaris muscle of both sexes and in the soleus muscle of male mice but not in female mice. Irrespective of sex, phosphofructokinase and lactate dehydrogenase (LDH) activities decreased in the plantaris and soleus muscles. Additionally, hexokinase activity in the plantaris muscle and LDH activity in the soleus muscle decreased to a greater extent in aged male mice compared with those in aged female mice. Mitochondrial enzyme activities increased in the plantaris muscle of aged female mice but did not change in male mice. The protein content of the glucose transporter 4 in the aged plantaris muscle and fatty acid translocase/cluster of differentiation 36 increased in the aged plantaris and soleus muscles of both sexes, with a significantly higher content in female mice. These findings suggest that females possess a better ability to maintain metabolic enzyme activity and higher levels of metabolite transport proteins in skeletal muscle during aging, despite alterations in lipid metabolism. Our data provide a basis for studying muscle metabolism in the context of age-dependent metabolic perturbations and diseases that affect females and males differently.