Enzymes Of Energy Metabolism Research Articles

Early postmortem beef muscle proteome and metabolome variations due to supranutritional zinc and ractopamine hydrochloride supplementation.

It was hypothesized that the longissimus thoracis (LT) muscle proteome, phosphoproteome, and metabolome could explain postmortem metabolism and tenderness differences in muscle from cattle supplemented zinc (Zn) and/or ractopamine hydrochloride (RH). High percentage Angus steers (N = 20) were fed in a 2 × 2 factorial assigned to Zn and RH treatments: control (CON; n = 10; analyzed 36mg Zn/kg dry matter [DM]) or supranutritional Zn supplementation (SUPZN; n = 10; control diet + 60mg Zn/kg DM [from ZnSO4] + 60mg Zn/kg DM [from Zn-amino acid complex]) for the entire 89-d trial. During the 28 d before harvest, steers were blocked by body weight within Zn treatments to RH treatments of 0 (NO; n = 10) or 300mg (RAC; n = 10) per steer per day. Steers were harvested at the Iowa State Meat Laboratory, where pH decline (1, 3, 6, and 24h postmortem) was measured. At 24h postmortem, LT muscle sections were removed from carcasses, and steaks were analyzed for Warner-Bratzler shear force (WBSF) values at 1, 3, 7, and 14 d postmortem. Muscle samples were taken at 1h, 1, 3, 7, and 14 d postmortem for the following analysis: troponin-T degradation (1, 3, 7, and 14 d postmortem), myosin heavy chain analysis (1h postmortem), sarcoplasmic proteome analysis through tandem mass tagging analysis (1h and 1 d postmortem), metabolome analysis (1h and 1 d postmortem), and phosphoproteome analysis (1h postmortem). SUPZN-NO tended to have a lower (P = 0.06) pH at 6h postmortem and a lower WBSF value (P = 0.06) at 1 d postmortem. CON-RAC had a higher (P = 0.04) pH at 6h postmortem and WBSF value (P < 0.01) at 1 d postmortem. A lower pH at 6h postmortem and lower WBSF value at 1 d postmortem in the SUPZN-NO treatment was accompanied by more sorbitol and fructose at 1 d postmortem, and less myosin regulatory light chain 2 at 1h postmortem, and less adenosine monophosphate deaminase 1 (AMPD1) at 1 d postmortem than all other treatments. A higher pH at 6h postmortem and higher WBSF value at 1 d postmortem in CON-RAC and SUPZN-RAC was accompanied by more soluble structural proteins (troponin-T and myosin-7) at 1h postmortem than CON-NO. At 1h postmortem, CON-RAC had more glyceraldehyde-3-phosphate dehydrogenase than CON-NO or SUPZN-RAC. Differences in energy metabolism enzymes, metabolites, and structural proteins may affect ATP production, rigor development, and lactate buildup which may explain the differences in postmortem metabolism and tenderness development at 1 d postmortem.

Cryopreservation of Goldlined seabream Rhabdosargus sarba (Forsskål, 1775) sperm: CASA observation and enzyme activity evaluation

In this study, we developed an optimized cryopreservation protocol for goldlined seabream sperm through five small experimental groups: Diluting the sperm with a mixed cryoprotectant (containing 10 g/L glucose and 10% DMSO in an RS extender) at a ratio of 1:3, followed by equilibration at 4 °C for 30 min. Subsequently, the samples were subjected to liquid nitrogen steam fumigation at 5 cm above the surface for 5 min before drop in the liquid nitrogen. Using computer-assisted sperm analysis (CASA), we examined the motility parameters of the sperm before and after freezing for 2 days, as well as the changes in energy metabolism enzyme (T-ATP, LDH, SDH) activities and antioxidant enzyme (T-GSH, CAT, SOD, and GSH-px) activities at 0, 5, 10, and 20 days after freezing. After 250 days cryopreservation, fluorescence staining of sperm showed that most cell membranes were less damaged, and the fertilization rate of sperm after 250 days cryopreservation was 72.53 ± 7.32%. objective of this study was to select an effective cryopreservation protocol for goldlined seabream sperm and elucidate the physiological damage mechanisms before and after cryopreservation.

Methyl jasmonate suppressed the pericarp browning in postharvest longan fruit by modulating membrane lipid and energy metabolisms

Methyl jasmonate (MeJA) is an important bioactive metabolite in fruits and vegetables that regulates various physiological processes. The effects of MeJA on pericarp browning in longan fruit and its underlying mechanism were investigated. Results showed that treatment with 100 μM MeJA substantially suppressed the development of pericarp browning in harvested longan fruit. Compared to untreated fruit, MeJA-treated fruit exhibited reduced cell membrane permeability during storage. Meanwhile, MeJA-treated fruit displayed lower levels of phosphatidic acid and higher content of phosphatidylcholine, phosphatidylinositol, phosphatidylglycerol, and phosphatidylethanolamine through suppressing the activities of key enzymes involved in membrane lipids metabolism, such as phospholipases, lipase and lipoxygenase. Furthermore, MeJA treatment enhances the energy status of the fruit, evidenced by elevated the levels of adenosine triphosphate and energy charge. This effect could be attributed to the enhanced activities of various energy metabolism enzymes. Overall, all results suggest that MeJA is a promising agent for inhibiting pericarp browning in longan fruit through modulation of membrane lipid and energy metabolisms.

Activities of Energy Metabolism Enzymes in Atlantic Salmon Salmo salar L. Smolts and Parr Grown under Different Light Regimens.

Activities of enzymes of energy and carbohydrate metabolism in muscles and the liver were studied in Atlantic salmon Salmo salar L. smolts and parr grown under continuous or natural lighting and different feeding regimens in autumn followed by a short photoperiod in winter. Enzyme activities were found to differ between test and control salmon groups and between parr and smolts sampled at the end of the winter period. Smolts grown under continuous lighting and round-the-clock feeding differed from other groups by having higher cytochrome c oxidase (COX) activity and lower aldolase activity in muscles. Differences in aerobic metabolism in muscles between parr and smolts were found to be the same in all experimental groups, COX and aldolase activities being relatively higher in smolts. The pattern of changes in enzyme activities in the liver from parr to smolts differed between different experimental groups. Based on the results, the photoperiod was assumed to affect the activities of energy metabolism enzymes in salmon juveniles and may eventually affect the completion of smoltification.

Inflammation and mitochondria in the pathogenesis of chronic Chagas disease cardiomyopathy.

Chagas disease (CD), caused by the protozoan parasite Trypanosoma cruzi, is a neglected disease affecting around 6 million people. About 30% of CD patients develop chronic Chagas disease cardiomyopathy (CCC), an inflammatory cardiomyopathy that occurs decades after the initial infection, while most infected patients (60%) remain asymptomatic in the so-called indeterminate form (IF). Death results from heart failure or arrhythmia in a subset of CCC patients. Myocardial fibrosis, inflammation, and mitochondrial dysfunction are involved in the arrhythmia substrate and triggering events. Survival in CCC is worse than in other cardiomyopathies, which may be linked to a Th1-T cell rich myocarditis with abundant interferon (IFN)-γ and tumor necrosis factor (TNF)-α, selectively lower levels of mitochondrial energy metabolism enzymes in the heart, and reduced levels of high-energy phosphate, indicating poor adenosine triphosphate (ATP) production. IFN-γ and TNF-α signaling, which are constitutively upregulated in CD patients, negatively affect mitochondrial function in cardiomyocytes, recapitulating findings in CCC heart tissue. Genetic studies such as whole-exome sequencing (WES) in nuclear families with multiple CCC/IF cases has disclosed rare heterozygous pathogenic variants in mitochondrial and inflammatory genes segregating in CCC cases. In this minireview, we summarized studies showing how IFN-γ and TNF-α affect cell energy generation, mitochondrial health, and redox homeostasis in cardiomyocytes, in addition to human CD and mitochondria. We hypothesize that cytokine-induced mitochondrial dysfunction in genetically predisposed patients may be the underlying cause of CCC severity and we believe this mechanism may have a bearing on other inflammatory cardiomyopathies.

Effects of light quality and intensity on the juvenile physiological metabolism of Babylonia areolata

Babylonia areolata lives in bottom sediments during the day and emerges at night to forage. This study examined how different light qualities (blue, white, green, and red light) and intensities (0 and 2–32 μmol·m s−1) influence the growth and physiological activity of B. areolate juveniles. Changes in the activity of digestive enzymes, such as pepsin (PPS), lipase (LPS), and amylase (AMS), as well as energy metabolic enzymes, such as hexokinase (HK), pyruvate kinase (PK), lactic dehydrogenase (LDH) and succinic dehydrogenase (SDH), were also studied. The result showed that juveniles exhibited substantial variations under different light conditions. Specifically, the maximum bodyweight specific growth rates (SGR) under green, blue, red, and white light conditions were 3.56 ± 0.45 %·d−1, 3.03 ± 0.68 %·d−1, 3.01 ± 0.72 %·d−1 and 2.99 ± 0.73 %·d−1 at light intensities of 2 μmol·m−2·s−1, 4 μmol·m−2·s−1, 8 μmol·m−2·s−1 and 2 μmol·m−2·s−1, respectively. The shell length SGR, shell width SGR and body weight SGR in the dark group were not statistically different from those in the red light group at 2 μmol·m−2·s−1 (p > 0.05), while the body weight SGR of the dark group was significantly lower than that in other groups (p < 0.05). At the light intensity of 2 μmol·m−2·s−1, the activity of PPS in green and blue light was significantly higher than in red light (p < 0.05). The activity of HK in green light was considerably higher than that in darkness (p < 0.05), and there was no significant difference in the activity of LDH between the dark group and the red light group (p > 0.05), although the results of both groups were significantly higher than those of the blue and white light (p < 0.05). In addition, the activity of PPS, AMS, HK, PK, and LDH was considerably higher in darkness than in other light qualities (p < 0.05). Under different light qualities, the activity of all enzymes at the low light intensity was significantly higher than that at the high light intensity (p < 0.05), which coincided with growth characteristics. Therefore, blue and green light promoted the growth of juveniles at low light intensity (2 μmol·m−2·s−1), but darkness inhibited their growth. The findings of this study could be used as a foundation for optimizing lighting conditions and figuring out the optimum conditions for the growth and survival of B. areolata. Furthermore, this study could help explain how to control lighting conditions in real-world breeding situations.

Efficacy of verbascoside, echinacoside, crenatoside on altitude-induced fatigue in rats and possible mechanism.

To study the efficacy and mechanism of three phenylethanoid glycosides (PhGs) (verbascoside, echinacoside, and crenatoside) on altitude-induced fatigue in rats. Altitude-induced fatigue model rats were established in a large hypobaric chamber. Swimming time, energy storage substances, metabolic enzymes, and metabolites were used to evaluate the anti-fatigue activities and mechanism of three PhGs (verbascoside, echinacoside, and crenatoside) (150 mg/kg, intragastric administration) in the hypoxic environment. The three PhGs, especially verbascoside, could prolong the swimming time of rats, ameliorate the edema and inflammatory infiltration of liver and skeletal muscle, increase the level of energy storage substances, reduce the decomposition of proteins, and exhibit positive effects on the metabolism-related enzyme activity and metabolites. The PhGs, especially verbascoside, are very potential with anti-fatigue activity in hypoxia. The mechanism may be explained with regulation of energy metabolism and reduction of oxidative stress.

Effect of calcium spray at flowering combined with post-harvest 1-MCP treatment on the preservation of grapes

These tests were carried out to find out how calcium and 1-MCP treatment affected the preservation of grapes, as grapes are highly susceptible to decay during post-harvest storage. The grapes were treated with 5 g/L calcium at the flowering stage, followed by 1 μL/L 1-MCP treatment after harvesting.When grapevines were treated with a combination of calcium and 1-MCP, the marketable fruit rate (At day 56 of storage, the 1-MCP + Ca2+ treatment group was still 93%, an increase of 29.03% compared to the control group.) and quality improved (At day 28 of storage, the VC content of the 1-MCP + Ca2+ treated group was 4.35 mg/100g, an increase of 25.01% compared to the control group.), while the fruit weight loss rate decreased (At day 56 of storage, the weight loss of the control group was 6.97%, an increase of 39.43% compared to the 1-MCP + Ca2+ treated group.).According to the experimental results, there are several reasons for this. First, in the early stages of fruit storage, the concentration of soluble pectin and soluble fiber, as well as the activities of pectinase and cellulase (related gene levels) were decreased. Secondly, the activity of antioxidant enzymes was increased, while MDA content was decreased. Third, during fruit storage, the respiratory intensity and ethylene release rate were reduced, as was the activity of energy metabolism enzymes. As a result, the aging and deterioration of the fruit during storage were delayed. Principal component analysis revealed that the calcium and 1-MCP combination therapy slowed the decline in grape berry quality, followed by the calcium-treated and 1-MCP-treated fruits. In contrast, grape berry quality declined the most rapidly in the control group.

Lycorine promotes IDH1 acetylation to induce mitochondrial dynamics imbalance in colorectal cancer cells

Isocitrate dehydrogenase (IDH) 1 and 2, as essential enzymes in energy metabolism, contribute to the survival and drug resistance of a variety of solid tumors, especially for colorectal cancer (CRC). However, the underlying molecular mechanism still remains unclear. In this study, IDH1 was identified as a crucial cellular target of a natural-derived anti-CRC small molecule lycorine, using the unbiased thermal proteome profiling (TPP) strategy. We found that lycorine directly targeted a unique C-terminal domain of IDH1, and disrupted IDH1 interaction with deacetylase sirtuin 1 (SIRT1), thereby significantly promoting IDH1 acetylation modification. Then, lycorine noticeably triggered oxidative stress in CRC cells to cause mitochondrial membranes injury, and subsequently facilitated mitochondrial fission. Specific knockdown of IDH1 or SIRT1 markedly aggrieved lycorine-mediated oxidative stress and mitochondrial fragmentation in CRC cells. Furthermore, the combination of lycorine and sirtuins blocker nicotinamide (NAM) exhibited a synergic therapeutic effect in CRC cells. Collectively, our results reveal that IDH1 may serve as a promising therapeutic target for CRC via pharmacologically driving oxidative stress-dependent mitochondrial dynamics imbalance.

Evaluation of light irradiation on anthocyanins and energy metabolism of grape (Vitis vinifera L.) during storage

Grape is the world’s economic horticultural crop; it is perishable due to various pathogens and abiotic stress attributed to water loss-induced issues. To address these postharvest problems, this research investigates the effects of light irradiation on anthocyanins synthesis and energy metabolism in stored grapes to enhance their postharvest quality. The activities of chlorophyllase (1.17 U gk−1), Mg-dechelatase (351.69 U gk−1), chlorophyll-degraded peroxidase (3.49 U gk−1), and pheophytinase (0.85 U gk−1) were significantly higher in the control fruit than in the treated fruit at the end of storage. The red-light treatment showed higher levels of anthocyanins biosynthesis-related enzymes than green, blue-light, and control treatments. Additionally, light irradiation resulted in a decrease in adenosine triphosphate, adenosine diphosphate, adenosine monophosphate, and energy charge. This was attributed to decreased activity of energy metabolism enzymes, reduced nicotinamide adenine dinucleotide phosphate content, and increased nicotinamide adenine dinucleotide content. These findings offer a theoretical foundation for optimizing grape coloration and energy metabolism during storage, thus prolonging the shelf-life of grapes by improving quality attributes. This research highlights the potential of light irradiation as a technique for enhancing the postharvest quality of agricultural products.

Role of TRDMT1/DNMT2 in stress adaptation and its influence on transcriptome and proteome dynamics under osmotic stress in Physcomitrium patens.

Early land plants such as the moss Physcomitrium patens lack several morphological traits that offer protection to tracheophytes from environmental stresses. These plants instead have evolved several physiological and biochemical mechanisms that facilitate them to adapt to terrestrial stresses such as drought. We have previously shown that loss-of-function mutants of tRNA (cytosine(38)-C(5))-methyltransferase TRDMT1/DNMT2 in P. patens are highly sensitive to oxidative and osmotic stress. To gain insight into the role of PpTRDMT1/PpDNMT2 in modulating genetic networks under osmotic stress, genome-wide transcriptome and proteome studies were undertaken in wild-type and ppdnmt2 plants. Transcriptome analysis revealed 375 genes to be differentially expressed in the ppdnmt2 under stress compared to the WT. Most of these genes are affiliated with carbohydrate metabolic pathways, photosynthesis, cell wall biogenesis, pathways related to isotropic and polarised cell growth and transcription factors among others. Histochemical staining showed elevated levels of reactive oxygen species in ppdnmt2 while transmission electron microscopy revealed no distinct defects in the ultrastructure of chloroplasts. Immunoprecipitation using PpDNMT2-specific antibody coupled with mass spectrometry revealed core proteins of the glycolytic pathway, antioxidant enzymes, proteins of amino acid biosynthetic pathways and photosynthesis-related proteins among others to co-purify with PpTRDMT1/PpDNMT2 under osmotic stress. Yeast two-hybrid assays, protein deletion and α-galactosidase assays showed the cytosol glycolytic protein glyceraldehyde 3-phosphate dehydrogenase to bind to the catalytic motifs in PpTRDMT1/PpDNMT2. Results presented in this study allow us to better understand genetic networks linking enzymes of energy metabolism, epigenetic processes and RNA pol II-mediated transcription during osmotic stress tolerance in P. patens.

Plasma proteome of growing tumors

Early detection of cancer is vital for the best chance of successful treatment, but half of all cancers are diagnosed at an advanced stage. A simple and reliable blood screening test applied routinely would therefore address a major unmet medical need. To gain insight into the value of protein biomarkers in early detection and stratification of cancer we determined the time course of changes in the plasma proteome of mice carrying transplanted human lung, breast, colon, or ovarian tumors. For protein measurements we used an aptamer-based assay which simultaneously measures ~ 5000 proteins. Along with tumor lineage-specific biomarkers, we also found 15 markers shared among all cancer types that included the energy metabolism enzymes glyceraldehyde-3-phosphate dehydrogenase, glucose-6-phophate isomerase and dihydrolipoyl dehydrogenase as well as several important biomarkers for maintaining protein, lipid, nucleotide, or carbohydrate balance such as tryptophanyl t-RNA synthetase and nucleoside diphosphate kinase. Using significantly altered proteins in the tumor bearing mice, we developed models to stratify tumor types and to estimate the minimum detectable tumor volume. Finally, we identified significantly enriched common and unique biological pathways among the eight tumor cell lines tested.

Energy metabolism: a new target for gastric cancer treatment.

Gastric cancer is the fifth most common malignancy worldwide having the fourth highest mortality rate. Energy metabolism is key and closely linked to tumour development. Most important in the reprogramming of cancer metabolism is the Warburg effect, which suggests that tumour cells will utilise glycolysis even with normal oxygen levels. Various molecules exert their effects by acting on enzymes in the glycolytic pathway, integral to glycolysis. Second, mitochondrial abnormalities in the reprogramming of energy metabolism, with consequences for glutamine metabolism, the tricarboxylic acid cycle and oxidative phosphorylation, abnormal fatty acid oxidation and plasma lipoprotein metabolism are important components of tumour metabolism. Third, inflammation-induced oxidative stress is a danger signal for cancer. Fourth, patterns of signalling pathways involve all aspects of metabolic transduction, and many clinical drugs exert their anticancer effects through energy metabolic signalling. This review summarises research on energy metabolism genes, enzymes and proteins and transduction pathways associated with gastric cancer, and discusses the mechanisms affecting their effects on postoperative treatment resistance and prognoses of gastric cancer. We believe that an in-depth understanding of energy metabolism reprogramming will aid the diagnosis and subsequent treatment of gastric cancer.

Lipopolysaccharide impairs neurodevelopment and induces changes in astroglial reactivity, antioxidant defenses and bioenergetics in the cerebral cortex of neonatal rats.

Neonates have an immature immune system, which increases their vulnerability to infectious agents and inflammatory insults. The administration of the immunostimulatory agent lipopolysaccharide (LPS) has been shown to induce the expression of pro-inflammatory cytokines and cause behavior alterations in rodents at different ages. However, the effects of LPS administration during the neonatal period and its consequences during immune system maturation remain to be elucidated. We showed here that a single intraperitoneal administration of LPS in rats on postnatal day (PND) 7 caused early and variable alterations in TNF-α, S100B and GFAP levels in the cerebral cortex, CSF and serum of the animals, indicating long-term induction of neuroinflammation and astroglial reactivity. However, on PND 21, only GFAP levels were increased by LPS. Additionally, LPS induced oxidative stress and altered energy metabolism enzymes in the cerebral cortex on PND 21, and caused neurodevelopment impairment over time. These data suggest that neuroinflammation induction during the neonatal period induces glial reactivity, oxidative stress and bioenergetic disruption that may lead to neurodevelopment impairment and cognitive deficit in adult life.

Transcriptomic analysis of the insecticidal activities of methyl benzoate against red flour beetle Tribolium castaneum (Herbst) larvae

Methyl benzoate (MB) is a common component of floral scents released by many plants. Recent research showed that MB was an alternative insecticide to control insect pests. However, the molecular mechanisms of insect pests in responses to MB are largely unknown, which limits the future applications of this promising insecticidal candidate. In this study, the total transcriptomic analysis for red flour beetle larvae after MB fumigation was performed. Of the 430 identified differentially expressed genes, 197 were upregulated and 233 were downregulated. GO and KEGG pathway enrichment were used to interpret gene classification/function and metabolic/signaling pathways, respectively. And we performed RT-qPCR to validate expressional profiles of identified DEGs. Genes that are involved in energy metabolism, xenobiotic metabolism, and digestive enzymes were shown to be differentially expressed, suggesting that MB have an impact on these physiological processes. This research will enrich our knowledge about the mechanisms of MB-fumigation response genes for stored-product pests. A better understanding of molecular response to MB will facilitate future applications to control stored-product pests.

EFFECT OF SALINITY ON THE ACTIVITY OF OXIDOREDUCTASES IN TISSUES OF THE ARK CLAM ANADARA KAGOSHIMENSIS (TOKUNAGA, 1906), A BLACK SEA INVADER

Effect of salinity on the activity of the enzymes of energy metabolism and antioxidant protection: malate dehydrogenase (MDH, 1.1.1.37), lactate dehydrogenase (LDH, 1.1.1.27), and catalase (1.11.1.6) was studied in the tissues of anadara. Four groups of adult molluscs (shell length of 37.0-55.5 mm) were exposed to different salinity (15‰, 25‰, 35‰ and 45‰) for two days at a water temperature of 21 °C and constant aeration (6.5± 0.3 mg O2/L). MDH activity reached its maximum value in the tissue of the foot and hepatopancreas at a native salinity for the invader - 35‰, that exceeded 1.7-fold ( p &lt;0.05) its values under 15 and 25‰ in both tissues; in the gills that activity of the enzyme remained at a constant level. A trend towards an increase in LDH activity in the foot and gills by 24-48% was found under salinity of 25-35‰ against the background of extremely low activity of the enzyme in the hepatopancreas in all experiments. A negative correlation ( r ) between the MDH/LDH index and LDH activity (from -0.66 to -0.82, p &lt;0.05) was found in the foot and gills. The maximum activity of catalase in the foot, gills, and hepatopancreas was noted in the salinity range of 25-35‰. In the gills, a significant correlation was found between the activity of catalase and LDH at 25‰ ( r = 0.72, p &lt;0.05) and 35‰ ( r = 0.96, p &lt;0.05), as well as the activity of catalase and MDH ( r = 0.71-0.89, p &lt;0.05) over the studied salinity range. In the anadara a synchronous decrease in the activity of oxidoreductases beyond the optimal salinity (25-35‰) may be one of the reasons for the slowdown in the growth of molluscs in water bodies where salinity is not optimal.

How Can Different Land Use Impact Aquatic Organisms? An Evaluation of Metabolic Alterations During Embryonic Development of Freshwater Fish, Rhamdia quelen

Chemical compounds used in agricultural activities are constantly leaching to water bodies where they can potentially cause damage to non-target organisms. In this study, we attempt to understand how the change in land use and exposure to xenobiotic substances may alter the metabolism and neurotoxicity during the development of native fish. Embryonic development of Rhamdia quelen was used as a quality indicator of two different aquatic environments, a stream considered impacted (Tormenta) and another reference (Manoel Gomes). The eggs were exposed to water collected from the reference and impacted streams during the development period (12h, 24h, 48h, and, 72h). Changes in the activity of energy metabolism enzymes (HK, PFK, LDH, CS, MDH) and the antioxidant defense system (CAT, GPX, GR, GST) were observed in animals exposed to impacted stream water. The entry of xenobiotic compounds into rivers through the leaching of chemical molecules existent in the soil causes activation of enzymes with a detoxification function. Furthermore, inhibition of cholinesterase enzyme activity indicates contamination by anticholinesterase compounds such as organophosphates and carbamates. Sites with constant use of these compounds can trigger harmful effects to organisms in the early stages of fish development and alter the body's metabolic and defense enzymatic activities.

Influence of Isolated Resistance Exercise on Cardiac Remodeling, Myocardial Oxidative Stress, and Metabolism in Infarcted Rats.

Exercise is an important therapeutic strategy for preventing and treating myocardial infarction (MI)-induced cardiac remodeling and heart failure. However, the myocardial effects of resistance exercise on infarcted hearts are not completely established. In this study, we investigated the effects of resistance exercise on structural, functional, and molecular cardiac alterations in infarcted rats. Three months after MI induction or simulated surgery, Wistar rats were assigned into three groups: Sham (n = 14); MI (n = 9); and exercised MI (MI-Ex, n = 13). Exercised rats performed, 3 times a week for 12 weeks, four climbs on a ladder with progressive loads. Cardiac structure and left ventricle (LV) function were analyzed by echocardiogram. Myocyte diameters were evaluated in hematoxylin- and eosin-stained histological sections as the smallest distance between borders drawn across the nucleus. Myocardial energy metabolism, lipid hydroperoxide, malondialdehyde, protein carbonylation, and antioxidant enzyme activities were evaluated by spectrophotometry. Gene expressions of NADPH oxidase subunits were evaluated by RT-PCR. Statistical analyses were performed using ANOVA and Tukey or Kruskal-Wallis and Dunn's test. Mortality did not differ between the MI-Ex and MI groups. MI had dilated left atrium and LV, with LV systolic dysfunction. Exercise increased the maximum load-carrying capacity, with no changes in cardiac structure or LV function. Myocyte diameters were lower in MI than in Sham and MI-Ex. Lactate dehydrogenase and creatine kinase activity were lower in MI than in Sham. Citrate synthase and catalase activity were lower in MI and MI-Ex than in Sham. Lipid hydroperoxide concentration was lower in MI-Ex than in MI. Nox2 and p22phox gene expressions were higher in MI-Ex than in Sham. Gene expression of Nox4 was higher in MI and MI-Ex than in Sham, and p47phox was lower in MI than in Sham. Late resistance exercise was safe in infarcted rats. Resistance exercise improved maximum load-carrying capacity, reduced myocardial oxidative stress, and preserved myocardial metabolism, with no changes in cardiac structure or left ventricle function in infarcted rats.

The Effects of Peanut Oligopeptides on Exercise-Induced Fatigue in Mice and Its Underlying Mechanism

The aim of this study was to clarify the anti-fatigue effect of peanut oligopeptides (POPs) in mice and to investigate its possible underlying mechanism. A total of 150 male ICR mice were randomly assigned into five groups: control, whey protein (0.50 g/kg·bw), and three peanut peptide groups (0.25, 0.50, and 1.00 g/kg·bw). All the mice were treated with intra-gastric administration for 30 days. Following the intervention, a weight-loaded swimming test, blood lactate concentration, glycogen content, the activities of antioxidant factors and energy metabolism enzymes, and the function of mitochondria in the skeletal muscle were examined. The results show that POP intervention significantly prolonged the exhaustive swimming time, decreased blood lactate concentration levels, regulated the process of energy metabolism, and increased the level of antioxidant enzymes, muscle glycogen, and expressions of mtTFA and NRF-1 in the mitochondria of the gastrocnemius muscle. The results suggest that POPs produce an anti-fatigue effect in the animals, and they may exert this effect through the mechanism of improving the animals' antioxidant capacity to reduce oxidative damage levels and regulating the process of energy metabolism.

Proteomic and toxicological analysis of the response of dinoflagellate Alexandrium catenella to changes in NaNO3 concentration

Dinoflagellates of the genus Alexandrium cause Harmful Algal Blooms (HABs) in coastal waters worldwide, damaging marine environments, aquaculture, and human health. They synthesize potent neurotoxic alkaloids known as PSTs (i.e., Paralytic Shellfish Toxins), the etiological agents of PSP (i.e., Paralytic Shellfish Poisoning). In recent decades, the eutrophication of coastal waters with inorganic nitrogen (e.g., nitrate, nitrite, and ammonia) has increased the frequency and scale of HABs. PSTs concentrations within Alexandrium cells can increase by up to 76% after a nitrogen enrichment event; however, the mechanisms that underlie their biosynthesis in dinoflagellates remains unclear. This study combines mass spectrometry, bioinformatics, and toxicology and investigates the expression profiles of PSTs in Alexandrium catenella grown in 0.4, 0.9 and 1.3 mM NaNO3. Pathway analysis of protein expression revealed that tRNA amino acylation, glycolysis, TCA cycle and pigment biosynthesis were upregulated in 0.4 mM and downregulated in 1.3 mM NaNO3 compared to those grown in 0.9 mM NaNO3. Conversely, ATP synthesis, photosynthesis and arginine biosynthesis were downregulated in 0.4 mM and upregulated in 1.3 mM NaNO3. Additionally, the expression of proteins involved in PST biosynthesis (sxtA, sxtG, sxtV, sxtW and sxtZ) and overall PST production like STX, NEO, C1, C2, GTX1-6 and dcGTX2 was higher at lower nitrate concentrations. Therefore, increased nitrogen concentrations increase protein synthesis, photosynthesis, and energy metabolism and decrease enzyme expression in PST biosynthesis and production. This research provides new clues about how the changes in the nitrate concentration can modulate different metabolic pathways and the expression of PST biosynthesis in toxigenic dinoflagellates.