Energy Metabolism In Rats Research Articles

Phosphate Starvation by Energy Metabolism Disturbance in Candida albicansvip1Δ/Δ Induces Lipid Droplet Accumulation and Cell Membrane Damage.

Phosphorus in the form of phosphate (Pi) is an essential element for metabolic processes, including lipid metabolism. In yeast, the inositol polyphosphate kinase vip1 mediated synthesis of inositol heptakisphosphate (IP7) regulates the phosphate-responsive (PHO) signaling pathway, which plays an important role in response to Pi stress. The role of vip1 in Pi stress and lipid metabolism of Candida albicans has not yet been studied. We found that when vip1Δ/Δ was grown in glucose medium, if Pi was supplemented in the medium or mitochondrial Pi transporter was overexpressed in the strain, the lipid droplet (LD) content was reduced and membrane damage was alleviated. However, further studies showed that neither the addition of Pi nor the overexpression of the Pi transporter affected the energy balance of vip1Δ/Δ. In addition, the LD content of vip1Δ/Δ grown in Pi limitation medium PNMC was lower than that grown in SC, and the metabolic activity of vip1Δ/Δ grown in PNMC was also lower than that grown in SC medium. This suggests that the increase in Pi demand by a high energy metabolic rate is the cause of LD accumulation in vip1Δ/Δ. In addition, in the vip1Δ/Δ strains, the core transcription factor PHO4 in the PHO pathway was transported to the vacuole and degraded, which reduced the pathway activity. However, this does not mean that knocking out vip1 completely blocks the activation of the PHO pathway, because the LD content of vip1Δ/Δ grown in the medium with β-glycerol phosphate as the Pi source was significantly reduced. In summary, the increased Pi demand and the decreased PHO pathway activity in vip1Δ/Δ ultimately lead to LD accumulation and cell membrane damage.

Serum proteomic analysis reveals the differential dose effects of crocodile oil from Crocodylus siamensis on energy metabolism in rats.

Dietary fat composition is a potential major factor affecting energy metabolism. Crocodile oil (CO) is rich in mono- and poly-unsaturated fatty acids exhibiting anti-inflammatory and healing properties. This study investigated different levels of CO consumption on alterations and expression of proteins involved in energy metabolism in rats. Twenty-one male Sprague-Dawley rats were divided into three groups and administered sterile water (N) or different doses of CO [1% or 3% (v/w) CO] orally once daily for 8 weeks. Body weight gain, food intake, energy intake, blood lipid profiles, and serum energy-related metabolites were determined. The serum proteome was analyzed using shotgun proteomics, and the functions of several candidate proteins were classified using PANTHER software. There were no significant differences in body weight or energy intake were observed between groups. However, both CO-treated groups showed significantly decreased serum triglyceride (TG) levels (p < 0.05). Moreover, post-treatment serum TG levels in the 1%CO group were significantly lower than pre-treatment compared with other groups. The serum oxaloacetate level was also significantly higher in both CO groups than in the N group. The proteomic analysis classified 4,525 serum proteins and revealed more unique proteins involved in cellular metabolic activity in both CO-treated groups than in the N group. Self-organizing tree algorithm clustering of 295 shared differentially expressed proteins in both CO-treatment groups showed that upregulated hyper-expressed protein clusters in both CO groups were associated with catalytic activity and molecular activity on the same levels. CO simultaneously enhances energy metabolism and improves lipid profiles.

Oxygen consumption rates and respiratory carbon losses in three species of copepods(Acartia clausi, Calanus helgolandicus and Limnocalanus macrurus) during starvation

Calanoid copepods with different life cycle strategies demonstrate varied velocity in the utilization of energy resources during starvation. This study analyzes the influence of multiday starvation on the rate of total, basal and active energy metabolism in adult females of two Marmara Sea and one Baltic Sea species of copepods; epiplanktonic Acartia clausi unable to accumulate lipid reserves and mesoplanktonic Calanus helgolandicus with minor lipid reserves in the oil sac (approximately 7% of body volume) and the Baltic Sea copepod Limnocalanus macrurus in quasi-diapausing state with large lipid reserves in the oil sac (approximately 19% of body volume). Initially, total weight specific respiration rates were about 0.12 μg C per μg C body weight per day (d$^{-1}$) for both Marmara Sea species at 20 °C and 0.079 d$^{-1}$ in the Baltic L. macrurus at 14 °C, decreasing significantly by 1.6-2.5 times with starvation, while basal metabolic rates, measured in the same anesthetized individuals, was nearly constant during starvation. In this regard, the active metabolic rates, defined as the difference between the respiration rate of active and anesthetized individuals, decreased during starvation by 1.7 times in C. helgolandicus and by 4.7 and 6 times in A. clausi and L. macrurus, respectively. In A. clausi and C. helgolandicus with minimal lipid reserves, total daily energy expenditure (5.1% of initial body carbon content) was twice as high as in L. macrurus (2.2% of initial body carbon content daily), which has a large oil sac. Overall, the trend demonstrates that despite different energy reserves, a decrease in the total energy metabolism in copepods occurs due to a reduction in energy expenditure for locomotor activity.

Evaluation of Mitochondrial Turnover Using Fluorescence Microscopy in Drosophila.

Mitochondrial dysfunction is associated with perturbations in the cellular oxidative status, changes in energy production and metabolic rate, and the onset of pathological processes. Classic methods of assessing mitochondrial dysfunction rely on indirect measures, such as evaluating mitochondrial DNA copy numbers, or direct but more costly and skilled techniques, such as electron microscopy. The protocol presented here was recently implemented to evaluate mitochondrial dysfunction in response to insecticide exposure in Drosophila melanogaster larvae, and it relies on the use of a previously established MitoTimer mutant strain. MitoTimer is a genetically engineered mitochondrial protein that shows green fluorescence when newly synthetized, irreversibly turning into red as mitochondria age. The protocol described here allows for the easy and direct assessment of shifts in mitochondrial turnover, with tissue-specific accuracy. This protocol can be adapted to assess changes in mitochondrial turnover in response to drugs, rearing conditions, and/or mutations in larva, pupa, or adult fruit flies.

Discussion on the application of ventilatory threshold in classification of physical workload in plateau

Objective: To explore the application of the first ventilatory threshold (VT1) and the second ventilatory threshold (VT2) in the classification of physical workload for plateau workers, to provide reference for formulating the classification in plateau. Methods: In August 2018, 88 male workers from substations at different altitudes (500 m, 2000 m, 3000 m and 4000 m) of a company were selected as study subjects by cluster sampling. They were divided into plain group and plateau groups.The intensities of workload were simulated by power bicycle, and physiologic parameters, including VO(2), heart rate (HR) and energy metabolic rate per body surface area (E/BSA) , were recorded in test system when reaching VT1, VT2 and peak oxygen uptake (VO(2)Peak) . The ratios of VT1, VT2 and VO(2)Peak to the quiet and work potential at different altitudes were compared. Results: In a quiet state, compared with the plain group, the HR and E/BSA of the workers in the 2000 m and 3000 m groups increased, and the differences were statistically significant (P<0.05) . At VT2, compared with the plain group, the HR of the workers in the 4000 m group decreased, the difference was statistically significant (P<0.05) . VO(2) and E/BSA of workers in each plateau group were lower than those in the plain group at VO(2)Peak, and the differences were statistically significant (P<0.05) . At VT2 and VO(2)Peak, the ratios of VO(2), HR, and E/BSA relative to the quiet state of the workers in each plateau group were lower than those of the plain group, and the differences were statistically significant (P<0.05) . In the quiet state and VT1, compared with the plain group, the remaining percentages of VO(2) and E/BSA of workers in each plateau group decreased, and the differences were statistically significant (P<0.05) . Taking VT1, VT2 and VO(2)Peak as cut-off points and VO(2), HR and E/BSA as indicators, the physical workload in plateau could be divided into four levels, namely medium, heavy, extremely heavy and extreme physical workload. Conclusion: It is practicable to use ventilatory threshold to classification of physical workload. VT1 and VT2 can be applied to the classification in plateau to supplement and optimize current national standard of physical workload.

A systematic review and meta-analysis of the effect of treadmill desks on energy expenditure, sitting time and cardiometabolic health in adults

BackgroundAs the health risks of sedentary working environments become more clear, greater emphasis on the implementation of walking interventions to reduce sitting time is needed. In this systematic review and meta-analysis, we investigate the role of treadmill-desk interventions on energy expenditure, sitting time, and cardiometabolic health in adults with sedentary occupations.MethodsRelevant studies published in English were identified using CINAHL, EMBASE, MEDLINE, Web of Science, Scopus, and PubMed databases up to December 2020. Random effects meta-analysis models were used to pool study results.ResultsThirteen relevant studies (six workplaces and seven laboratories) were found with a total of 351 participants. Pooled analysis of laboratory studies showed a significant increase in energy expenditure (105.23 kcal per hour, 95% confidence interval [CI]: 90.41 to 120.4), as well as metabolic rate (5.0 mL/kg/min, 95% CI: 3.35 to 6.64), among treadmill desk users compared to sitting conditions. No evidence of significant differences in blood pressure were found. In workplace studies, we observed a significant reduction in sitting time over a 24-h period (− 1.73 min per hour, 95% CI: − 3.3 to − 0.17) among users of treadmill desks, compared to a conventional desk. However, there were no evidence of statistically significant changes in other metabolic outcomes.ConclusionsTreadmill desks offer a feasible and effective intervention to increase energy expenditure and metabolic rate and reduce sitting time while performing work-related tasks. Future studies are needed to increase generalizability to different workplace settings and further evaluate their impact on cardiometabolic health.

Cellular and Metabolite Changes in the Secondary Phloem of Chinese Fir (Cuninghamia lanceolata (Lamb.) Hook.) during Dormancy Release

Wood in the cold temperate zone is the product of the alternation of the growing season and the dormant period of trees, but our knowledge of the process of dormancy release in trees remains limited. Chinese fir (Cuninghamia lanceolata (Lamb.) Hook.) was used to investigate cellular and metabolite changes in the secondary phloem tissue during dormancy release. The sampling dates were 2 March, 28 March, and 13 April. The microsections of wood-forming tissue were prepared using the paraffin embedding technique to observe the formation of cambium cells; metabolites in secondary phloem cells were extracted using a methanol/chloroform organic solvent system. The results showed that the secondary phloem consists of phloem fibers, sieve cells and phloem parenchyma. The cells were regularly arranged in continuous tangential bands and were in the order of Phloem fiber-Sieve cell-Phloem parenchyma-Sieve cell-Phloem parenchyma-Sieve cell-Phloem parenchyma-Sieve cell-Sieve cell-Phloem parenchyma-. The Chinese fir cambium was in dormancy on 2 March and 28 March, while on 13 April, it was already in the active stage and two layers of xylem cells with several layers of phloem cells were newly formed. The width of the cambium zone increased from 18.7 ± 5.7 μm to 76.5 ± 3.0 μm and the average radial diameter of sieve cells expanded from 15.4 ± 7.5 μm to 21.5 ± 7.4 μm after dormancy release. The cambium zone width and the average radial diameter of sieve cells before and after dormancy release were significantly different (p &lt; 0.01). The phloem parenchyma cells without resin were squeezed and deformed by the sieve cells, and the width of the phloem during the active period was 197.0 ± 8.5 μm, which was larger than that during the dormant period. Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)-based metabolomics was employed to analyze the secondary phloem of Chinese fir on 28 March and 13 April. Thirty-nine differential metabolites during dormancy release were detected. The results showed that the composition of Chinese fir metabolites was different before and after dormancy release. The relative increase in pyruvic acid and ascorbic acid contents proved that the rate of energy metabolism in Chinese fir increased substantially after dormancy release. Changes in cell development and the composition of metabolites revealed that the dormancy release of Chinese fir was at early April and the formation period of phloem tissue is earlier than xylem tissue.

Mate Choice, Sex Roles and Sexual Cognition in Vertebrates: Mate Choice Turns Cognition or Cognition Turns Mate Choice?

The idea of “smart is sexy,” meaning superior cognition provides competitive benefits in mate choice and, therefore, evolutionary advantages in terms of reproductive fitness, is both exciting and captivating. Cognitively flexible individuals perceive and adapt more dynamically to (unpredictable) environmental changes. The sex roles that females and males adopt within their populations can vary greatly in response to the prevalent mating system. Based on how cognition determines these grossly divergent sex roles, different selection pressures could possibly shape the (progressive) evolution of cognitive abilities, suggesting the potential to induce sexual dimorphisms in superior cognitive abilities. Associations between an individual’s mating success, sexual traits and its cognitive abilities have been found consistently across vertebrate species and taxa, providing evidence that sexual selection may well shape the supporting cognitive prerequisites. Yet, while superior cognitive abilities provide benefits such as higher feeding success, improved antipredator behavior, or more favorable mate choice, they also claim costs such as higher energy levels and metabolic rates, which in turn may reduce fecundity, growth, or immune response. There is compelling evidence in a variety of vertebrate taxa that females appear to prefer skilled problem-solver males, i.e., they prefer those that appear to have better cognitive abilities. Consequently, cognition is also likely to have substantial effects on sexual selection processes. How the choosing sex assesses the cognitive abilities of potential mates has not been explored conclusively yet. Do cognitive skills guide an individual’s mate choice and does learning change an individual’s mate choice decisions? How and to which extent do individuals use their own cognitive skills to assess those of their conspecifics when choosing a mate? How does an individual’s role within a mating system influence the choice of the choosing sex in this context? Drawing on several examples from the vertebrate world, this review aims to elucidate various aspects associated with cognitive sex differences, the different roles of males and females in social and sexual interactions, and the potential influence of cognition on mate choice decisions. Finally, future perspectives aim to identify ways to answer the central question of how the triad of sex, cognition, and mate choice interacts.

A study of the influence of lead pollution on the anticoagulant activity of Whitmania pigra based on pharmacodynamics and metabolomics research

Whitmania pigra Whitman (leech, also called Shuizhi in China, abbreviated as SZ), which has been used as a traditional Chinese medicine in the treatment of blood stasis syndrome (BSS) for a long time, is vulnerable to lead pollution in aquaculture environments. SZ has good anticoagulant activity. However, there are few studies on the influence of lead pollution on it. Therefore, we carried out the following researches to explore the influence of lead pollution on the anticoagulant activity of SZ and its mechanism. Firstly, the acute blood stasis model of rats was established by subcutaneous injection of adrenaline hydrochloride and ice water bath. Then unpolluted SZ (UPS) and lead-polluted SZ (LPS) were extracted. Next, the blood stasis model rats were administrated by gavage and the rats in normal control (NC) group and blood stasis model (BM) group were given the same amount of normal saline. Finally, the blood of the rats was collected to detect the coagulation function and hemorheology indexes. The metabolomics of rat plasma was studied by ultra-high-performance liquid chromatography coupled with orbitrap mass spectrometry (UPLC-Orbitrap-MS) technology. Principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA) and Hierarchical clustering analysis (HCA) were used to perform metabolomics analysis. MetPA analysis was used to search for related metabolic pathways. The results of coagulation function and hemorheology showed that lead pollution could decrease the anticoagulant activity of SZ. The OPLS-DA score plots indicated that the plasma metabolites of rats in LPS group were close to BM group, while UPS group tended to be close to NC group both in the positive and negative ion mode. Hierarchical cluster analysis (HCA) suggested that UPS group and NC group were clustered into a branch, while LPS group and BM group were clustered into a branch. To sum up, lead pollution will reduce the anticoagulant activity of SZ. And lead pollution reduces the anticoagulant activity of SZ probably by influencing the metabolic pathways such as sphingolipid metabolism, amino acid metabolism and energy metabolism in rats.

Dimming the Powerhouse: Mitochondrial Dysfunction in the Liver and Skeletal Muscle of Intrauterine Growth Restricted Fetuses.

Intrauterine growth restriction (IUGR) of the fetus, resulting from placental insufficiency (PI), is characterized by low fetal oxygen and nutrient concentrations that stunt growth rates of metabolic organs. Numerous animal models of IUGR recapitulate pathophysiological conditions found in human fetuses with IUGR. These models provide insight into metabolic dysfunction in skeletal muscle and liver. For example, cellular energy production and metabolic rate are decreased in the skeletal muscle and liver of IUGR fetuses. These metabolic adaptations demonstrate that fundamental processes in mitochondria, such as substrate utilization and oxidative phosphorylation, are tempered in response to low oxygen and nutrient availability. As a central metabolic organelle, mitochondria coordinate cellular metabolism by coupling oxygen consumption to substrate utilization in concert with tissue energy demand and accretion. In IUGR fetuses, reducing mitochondrial metabolic capacity in response to nutrient restriction is advantageous to ensure fetal survival. If permanent, however, these adaptations may predispose IUGR fetuses toward metabolic diseases throughout life. Furthermore, these mitochondrial defects may underscore developmental programming that results in the sequela of metabolic pathologies. In this review, we examine how reduced nutrient availability in IUGR fetuses impacts skeletal muscle and liver substrate catabolism, and discuss how enzymatic processes governing mitochondrial function, such as the tricarboxylic acid cycle and electron transport chain, are regulated. Understanding how deficiencies in oxygen and substrate metabolism in response to placental restriction regulate skeletal muscle and liver metabolism is essential given the importance of these tissues in the development of later lifer metabolic dysfunction.

Immunomodulatory Effect of a New Ingredients Group Extracted from Astragalus Through Membrane Separation Technique.

IntroductionAstragalus is a commonly used traditional Chinese medicine in China, which has been widely applied to enhance the immunomodulatory function of the body. The main bioactive components are complicated. To explore the role of the components, various techniques have been applied in Astragalus extraction. Membrane separation technique featured with green processing condition and high efficiency is of signification interest in the application of Astragalus treatment.MethodsIn this study, a new ingredients group A4 was separated from Astragalus using membrane separation technique. The quantification and identification of A4 were achieved by UV-vis spectrometry and UPLC-MS measurements. Pathological approaches along with serum metabolomics were utilized to study the immunoprotective effects of the extracts and explore the underlying mechanisms on metabolic activity.ResultsIt was observed that A4 could promote the secretion of IL-2 and IFN-γ, stimulate the activated CD4+CD25+ and CD8+ CD25+ T lymphocytes in splenocytes and protect rat spleen to some extent. Seven crucial biomarkers that related to immunity regulations were screened out and identified through serum metabonomic analysis coupled with nuclear magnetic resonance. The enrichment analysis revealed that A4 alleviated the immune dysfunction by modulating amino acid metabolism and energy metabolism for the first time.ConclusionThe new ingredients group A4 isolated from the Astragalus membrane can reduce the immune dysfunction by regulating the amino acid metabolism and energy metabolism of rats.

The levels of relaxin and amino acids play a critical role in women with variable degree of preparedness for labour

Underlying biochemical factors that contribute towards the preparedness for labour and ripening of the cervix remain largely unknown. We aimed to characterize metabolic and hormonal determinants that constitute the preparedness for labour in women.&#x0D; The aim of the research was to study the content of relaxin and amino acids involved in its formation in primiparous pregnant women with various degrees of birth preparedness.&#x0D; Materials and methods: Prospective study has been conducted on 115 primiparous women at 38-40 weeks of gestation. Biochemical methods were used to analyse relaxin and amino acid levels in pregnant women with varying degree of birth preparedness. Results: the obtained data from the study indicate importance role of relaxin in the underlying pathogenesis in women with variable degree of preparedness for labour. The results allow to use the levels of relaxin serum as a predictor of the state of the birth canal. Furthermore, the amino acids are known to participate in various critical metabolic processes and play an important role is orchestrating many essential pathways in the body. We present the analysis of amino acids involved in the formation of relaxin in the serum of pregnant women. Our analysis has shown that amino acid imbalance leads to disruption of energy metabolism and blood flow rate, resulting in metabolic, structural and functional changes in the cervix at the onset of labour. Conclusion: considering the mechanisms of the possible influence of relaxin and amino acids on the cervical ripening, we concluded that correcting amino acid imbalance and normalising relaxin levels should be included in preinduction of labour therapeutic regimen. This would be an important step in improving the perinatal outcomes

Salt-inducible kinase 2 regulates energy metabolism in rats with cerebral ischemia-reperfusion.

To investigate the effects of salt-inducible kinase 2 (SIK2) on energy metabolism in rats with cerebral ischemia-reperfusion. Adult SD male rats were divided into 5 groups: sham group, ischemia group, reperfusion group, adenovirus no-load group, and SIK2 overexpression group with 5 animals in each group. The middle cerebral artery occlusion (MCAO) was induced with the modified Zea-Longa line thrombus method to establish the cerebral ischemia reperfusion model. Eight days before the MCAO, SIK2 overexpression was induced by injecting 7 μL adenovirus in the right ventricle, then MCAO was performed for followed by reperfusion HE staining was used to observe the pathological changes of cerebral tissue in rats; TTC staining was used to observe the volume of cerebral infarct. The levels of adenosine triphosphate (ATP) and adenosine diphosphate (ADP) in rat brain tissue were detected by ELISA; the levels of SIK2 and hypoxia-inducible factor 1α (HIF-1α) in the rat brain tissues were detected by RT-qPCR and Western blotting. Compared with the sham group, SIK2 level was decreased in the ischemia group, and it was further declined in the reperfusion group (<0.05). Compared with the sham group and ischemic group, the pathological injury in reperfusion group were more severe, and the infarct size was larger; compared with the reperfusion group and adenovirus no-load group, the pathological injury of the SIK2 overexpression group was milder, and the infarct size is less. Compared with the sharn group, HIF-1α was increased in both ischemia group and reperfusion group, especially in ischemia group (all <0.05); HIF-1α level in the SIK2 overexpression group was higher than that in the reperfusion group and adenovirus no-load group (all <0.05). ATP level in ischemia group and reperfusion group was lower than that in the sham group, and the reperfusion group decreased more significantly than the ischemia group (<0.05); ADP content was increased in the ischemia and reperfusion group, and the ADP content in reperfusion group was significantly higher than that in the ischemia group (<0.05). ATP level in the SIK2 overexpression group was higher than that in the reperfusion group and adenovirus no-load group (all <0.05), and ADP was decreased in the SIK2 overexpression group (all <0.05). SIK2 can up-regulate the ATP level and down-regulate the ADP level in rat brain tissue and alleviate cerebral ischemia-reperfusion injury by increase the level of HIF-1α.

Non-invasive assessment of metabolic responses to food restriction using urinary triiodothyronine and cortisol measurement in macaques

Regulation of energy allocation and metabolic rate plays an important role in determining behavior and fitness in wild animals, calling for the validation of non-invasive markers of energetic condition. Recently, the thyroid hormone triiodothyronine (T3) has emerged as a promising marker as concentrations decrease to lower the metabolic rate during energetically challenging periods. However, it remains largely unclear whether T3 merely represents an alternative or provides additional information compared to other compounds involved in the regulation of energy acquisition and allocation, like cortisol and C-peptide, as few joint measurements have been conducted to date in non-invasively collected samples. We aimed to validate the non-invasive measurement of immunoreactive urinary total T3 (uTT3), in comparison to urinary cortisol (uCort) and urinary C-peptide (uCP), as a marker of metabolic response to variation in food intake in macaques, and to address a number of issues regarding the collection, storage and processing of samples which are important for application of uTT3 measurements under field conditions. We used daily samples and body mass measures from a prior food restriction-refeeding experiment over 4 weeks with six captive macaques and analyzed concentrations of uTT3 and uCort in samples collected prior to (fasting) and after morning feeding (non-fasting). Concentrations of uTT3 decreased in response to restriction in food supply and were also lower during weeks of food restriction compared to weeks of refeeding. Variation in uTT3 also correlated positively with variation in body mass and concentrations of uCP. As expected, uCort showed the reverse pattern, increasing during food restriction and decreasing following refeeding, but was not associated with variation in body mass. Generally, compared to fasting samples, concentrations were higher in post-morning feeding, i.e. non-fasting, samples for uTT3 but not uCort. Contamination of urine samples with fecal matter, but not soil, and exposure to UV light led to a decrease in uTT3. uTT3 was largely unaffected by repeated freeze–thaw cycles and by refrigeration for medium-term storage (2 days) but degraded substantially when stored at ambient temperature for the same period. In conclusion, uTT3 measurements inform on the effect of food intake and its associated metabolic response to variation in energetic status. Since uTT3 is reasonably robust to many issues associated with collection and storage of urine samples under field conditions, it is a promising biomarker for studies of energetic condition and basal metabolic rate in wild macaques.

Microplastic consumption and physiological response in Acartia clausi and Centropages typicus: Possible roles of feeding mechanisms

Multi-day experiments were carried out with two Marmara Sea calanoid copepod species: Acartia clausi and Centropages typicus, to assess the possible role of the type of feeding on the consumption of microplastics and its influence on the rate of energy metabolism of these species. In a mixture of microplastic beads (6μm diameter) and algae Rhodomonas salina (5–10μm size range) with equal concentrations of about 5000 cells/beads mL −1 the ambush feeder A. clausi consumed almost 5 times less microplastic 858.8 ± 294.1 beads ind −1 day −1 than the cruising feeder C. typicus and halved its consumption of microplastics alone, while C. typicus, on the contrary, increased its consumption rate of pure microplastics to 20237.4 ± 7020.41 beads ind −1 day −1. Both types of reaction to microplastics lead to a decrease in the respiratory rates of the copepods. During the 5 days of maintenance on a solely microplastic diet, the respiration rates of A. clausi and C. typicus decreased 2.2 and 3.4 times, respectively, due to a decrease in the energy spent on motor activity, whilst maintaining basal metabolic energy. It has been shown that in A. clausi, consuming microplastics, a decrease in respiration rate occurs in the same way as in individuals starving in filtered water. A more rapid respiration rate decrease in Centropages typicus consuming microplastics may be due to the greater energy expenditure on microplastic beads capture and egestion via fecal pellets. Acartia clausi seems to exhibit a better strategy in dealing with the adverse consequences of microplastics consumption in comparison to Centropages typicus.

Temperature effect on water dynamics in tetramer phosphofructokinase matrix and the super-arrhenius respiration rate

Advances in understanding the temperature effect on water dynamics in cellular respiration are important for the modeling of integrated energy processes and metabolic rates. For more than half a century, experimental studies have contributed to the understanding of the catalytic role of water in respiration combustion, yet the detailed water dynamics remains elusive. We combine a super-Arrhenius model that links the temperature-dependent exponential growth rate of a population of plant cells to respiration, and an experiment on isotope labeled 18O2 uptake to H218O transport role and to a rate-limiting step of cellular respiration. We use Phosphofructokinase (PFK-1) as a prototype because this enzyme is known to be a pacemaker (a rate-limiting enzyme) in the glycolysis process of respiration. The characterization shows that PFK-1 water matrix dynamics are crucial for examining how respiration (PFK-1 tetramer complex breathing) rates respond to temperature change through a water and nano-channel network created by the enzyme folding surfaces, at both short and long (evolutionary) timescales. We not only reveal the nano-channel water network of PFK-1 tetramer hydration topography but also clarify how temperature drives the underlying respiration rates by mapping the channels of water diffusion with distinct dynamics in space and time. The results show that the PFK-1 assembly tetramer possesses a sustainable capacity in the regulation of the water network toward metabolic rates. The implications and limitations of the reciprocal-activation–reciprocal-temperature relationship for interpreting PFK-1 tetramer mechanisms are briefly discussed.

Bioenergetics and abnormal functional connectivity in psychotic disorders.

Psychotic Disorders such as schizophrenia (SZ) and bipolar disorder (BD) are characterized by abnormal functional connectivity (FC) within neural networks such as the default mode network (DMN), as well as attenuated anticorrelation between DMN and task-positive networks (TPN). Bioenergetic processes are critical for synaptic connectivity and are also abnormal in psychotic disorders. We therefore examined the association between brain energy metabolism and FC in psychotic disorders. 31P magnetization transfer spectroscopy from medial prefrontal cortex (MPFC) and whole-brain fMRI data were collected from demographically matched groups of SZ, BD, and healthy control (HC) subjects. The creatine kinase (CK) reaction flux calculated from spectroscopy was used as an index of regional energy production rate. FC maps were generated with MPFC as the seed region. Compared to HC, SZ showed significantly lower CK flux, while both BD and SZ patients showed decreased anticorrelation between MPFC and TPN. CK flux was significantly correlated with FC between MPFC and other DMN nodes in HC. This positive correlation was reduced modestly in BD and strongly in SZ. CK flux was negatively correlated with the anticorrelation between MPFC and TPN in HC, but this relationship was not observed in BD or SZ. These results indicate that MPFC energy metabolism rates are associated with stronger FC within networks and stronger anticorrelation between networks in HC. However, this association is decreased in SZ and BD, where bioenergetic and FC abnormalities are evident. This pattern may suggest that impairment in energy production in psychotic disorders underlies the impaired neural connectivity.

Short-term dietary restriction ameliorates brain injury after cardiac arrest by modulation of mitochondrial biogenesis and energy metabolism in rats.

BackgroundDietary restriction (DR) is a well-known intervention that increases lifespan and resistance to multiple forms of acute stress, including ischemia reperfusion injury. However, the effect of DR on neurological injury after cardiac arrest (CA) remains unknown.MethodsThe effect of short-term DR (one week of 70% reduced daily diet) on neurological injury was investigated in rats using an asphyxial CA model. The survival curve was obtained using Kaplan-Meier survival analysis. Serum S-100β levels were detected by enzyme linked immunosorbent assay. Cellular apoptosis and neuronal damage were assessed by terminal deoxyribonucleotide transferase dUTP nick end labeling assay and Nissl staining. The oxidative stress was evaluated by immunohistochemical staining of 8-hydroxy-2'-deoxyguanosine (8-OHdG). Mitochondrial biogenesis was examined by electron microscopy and mitochondrial DNA copy number determination. The protein expression was detected by western blot. The reactive oxygen species (ROS) and metabolite levels were measured by corresponding test kits.ResultsShort-term DR significantly improved 3-day survival, neurologic deficit scores (NDS) and decreased serum S-100β levels after CA. Short-term DR also significantly attenuated cellular apoptosis, neuronal damage and oxidative stress in the brain after CA. In addition, short-term DR increased mitochondrial biogenesis as well as brain PGC-1α and SIRT1 protein expression after CA. Moreover, short-term DR increased adenosine triphosphate, β-hydroxybutyrate, acetyl-CoA levels and nicotinamide adenine dinucleotide (NAD+)/reduced form of NAD+ (NADH) ratios as well as decreased serum lactate levels.ConclusionsReduction of oxidative stress, upregulation of mitochondrial biogenesis and increase of ketone body metabolism may play a crucial role in preserving neuronal function after CA under short-term DR.

Effect of Uygur medicine maturants on related factors of liver energy metabolism in rats

Objective: To investigate the effects of five Uygur medicine maturants on the related factors of liver energy metabolism in rats. Methods: After 30 days of preparation and intragastric administration, the weight changes of rats were observed. Enzyme-linked immunosorbent assay (ELISA) was used to detect Na[Formula: see text] K[Formula: see text] ATPase, Ca2[Formula: see text] Mg2[Formula: see text] ATPase and succinate dehydrogenase (SDH) activities; hepatic glycogen (HG) and muscle glycogen (MG) content, plasma triiodothyronine (T3), tetraiodothyronine (T4), and thyrotropin (TSH) content were detected. Results: The Kan (blood) quality regulator reduced the weight of rats, the Sapra regulator increased the weight of rats, the Savda maturant group, and the Balham maturant group increased the Na[Formula: see text] K[Formula: see text] ATPase, Ca2[Formula: see text] Mg2[Formula: see text] ATP, SDH activity, HG, MG, T3, T4, and TSH content of rats significantly, while the other groups had no significant effect on the energy metabolism-related factors. Conclusion: Five kinds of Uygur medicine maturants have effects on the related factors of energy metabolism in the liver of normal rats, and their elevation of serum thyroxine level is related, among which the effects of the Savda maturant group and the Balham maturant group are more significant.

Novel natural plant protein and mimetic peptides rescues aberrant brain‐energy metabolism and Alzheimer’s disease pathology

AbstractBackgroundExtensive evidence has indicated that a high rate of cholesterol biogenesis and abnormal neuronal energy metabolism play key roles in Alzheimer’s disease (AD) pathogenesis. Here, for the first time, we used protein and peptide, a plant protein homolog of mammalian adiponectin, to determine its therapeutic efficacy in different AD models.MethodMice were grouped before treatment as follows: WT and Transgenic mice (APP/PS1 and Adipo‐/‐ mice) were administered via intraperitoneal injection with 3 types of solution (saline, osmotin and osmotin mimetic peptide). Mice were decapitated at the age of 5, 9, 12 or 16 months. Protein samples were analyzed by immunobloting as well as immunofluorescence. Brain sections were analyzed by immune histochemistry. LTP was measured by mEPSC.ResultOsmotin, natural plant protein, and its mimetic peptide treatment modulated adiponectin receptor 1 (AdipoR1), significantly induced AMPK/SIRT1 activation, and reduced SREBP2 expression in both in vivo and in vitro AD and Adiponectin deficient mice. Osmotin acts Via AdipoR1/AMPK/SIRT1/SREBP2 and TNFR1 signaling pathway, Osmotin and its mimetic peptide significantly diminished amyloidogenic Aβ production, abundance and aggregation, accompanied by improved pre‐ and post‐synaptic dysfunction, cognitive impairment, memory deficits. Most importantly, it reversed the suppression of long‐term potentiation (LTP) in AD mice. Interestingly, AdipoR1, AMPK, and SIRT1 silencing not only abolished Osmotin capability but also further enhanced AD pathology by increasing SREBP2, APP, and β‐secretase (BACE1) expression and the levels of toxic Aβ production. Likewise, mimetic peptide mechanistically instigates AdipoR1/AMPK signaling and consequently suppressed the hyperactivated TNF‐α/TNFR1 signaling in both in vivo and in vitro models of AD.ConclusionOsmotin and its mimetic peptide mitigate aberrant brain‐energy metabolism and AD pathology in in vivo and in vitro AD models via regulating AdipoR1/AMPK/SIRT1/SREBP2/TNFR1 signaling pathway. These results suggest that Osmotin and peptide‐based mimetics can be a potential candidate for AD treatment.