Higher Oxygen Consumption Research Articles

Autochthonous sources and drought conditions drive anomalous oxygen-consuming pollution increase in a sluice-controlled reservoir in eastern China

Freshwater reservoirs are an important type of inland waterbody. However, they can suffer from oxygen-consuming pollution, which can seriously threaten drinking water safety and negatively impact the health of aquatic ecosystems. Oxygen-consuming pollutants originate from both allochthonous and autochthonous sources, and have temporally and spatially heterogeneous drivers. Datanggang Reservoir, China, is located in a small agricultural watershed; it is controlled by multiple sluice gates. Anomalously high oxygen consumption indicators were observed in this reservoir in March 2021. Here, it was hypothesized that autochthonous sources were the primary drivers of oxygen-consuming pollution in the reservoir under drought conditions. Datasets of water quality, precipitation, primary productivity, and sediment were used to analyze water quality trends in the reservoir and inflow rivers, demonstrating the effects of allochthonous inputs and autochthonous pollution. No correlation was found between reservoir oxygen consumption indicators and allochthonous inputs; reservoir oxygen consumption indicators and chlorophyll-a concentration were significantly positively correlated (p < 0.05). Substantially lower precipitation and higher water temperature and pH (compared to historical levels) were also observed before the pollution event. Therefore, during this period the hydrological conditions, water temperature, pH, and other variables caused by short-term drought conditions may have facilitated phytoplankton growth in the reservoir. This contributed to a large increase in autochthonous oxygen-consuming pollutants, as reflected by the abnormally high indicators. Sediments contaminated with organic matter may also have been an important contributor. As the effects of environmental management and pollution control continue to emerge, exogenous pollutants imported from the land to reservoirs are currently effectively controlled. However, endogenous pollutants driven by a variety of factors, such as meteorology and hydrology, will likely become the main drivers of short-term changes in oxygen-consuming pollution in freshwater reservoirs in the foreseeable future.

Abstract 3795: Early seeding of Richter transformation in chronic lymphocytic leukemia

Abstract Introduction: Clonal evolution drives cancer development due to the emergence and/or selection of proliferatively advantageous subclones. Its understanding may facilitate the design of anticipation-based management strategies. Richter transformation (RT) is a paradigmatic tumor evolution in which chronic lymphocytic leukemia (CLL), an indolent neoplasia of mature B-cells, transforms into a high-grade lymphoma, usually diffuse large B-cell lymphoma (DLBCL), conferring a dismal prognosis. The evolutionary trajectories of RT and its driving (epi)genomic mechanisms remain largely unknown. Aims: To reconstruct the evolutionary history of RT and to reveal the molecular processes underlying this transformation. Methods: We characterized the whole genome (WGS), epigenome (DNA methylation, H3K27ac, ATAC-seq), and transcriptome (RNA-seq), combined with single-cell DNA and RNA sequencing analyses, of 19 CLL patients developing RT before (n=3) or after treatment with chemoimmunotherapy (n=6) and targeted therapies (BCR or BCL2 inhibitors, n=10). We analyzed 54 longitudinal samples covering up to 19 years of disease course. Results: Our WGS analyses uncovered that RT is characterized by a remarkable structural complexity. We also identified a novel treatment-independent RT-specific mutational process, which we named SBS-RT. The genetic driver landscape of RT is a compendium of alterations in genes involved in cell cycle, MYC, and NF-κB pathways, frequently targeted in single catastrophic events including chromothripsis and chromoplexy. The WGS-based phylogenic reconstruction and single-cell DNA/RNA-seq analyses identified a very early diversification of CLL leading to emergence of RT-cells carrying specific genetic drivers and transcriptomic profiles of RT already at CLL diagnosis. These small subclones were dormant for 6-19 years until rapid expansion associated with the clinical transformation. While the DNA methylome kept track of the cell of origin and proliferative history of RT cells, their chromatin configuration and transcriptional program converged into the overexpression of cell cycle regulators, Toll-like receptors, MYC, MTORC1, and OXPHOS related transcripts, as well as downregulation of BCR pathway. This phenotypic shift was related to de novo activation of key transcription factors. In vitro experiments confirmed that RT cells have a 4-fold higher oxygen consumption at routine respiration and electron transfer system capacity compared to CLL. The resistance of RT to BCR inhibition is consistent with its high OXPHOS and low BCR signaling, which mimics de novo DLBCL-OXPHOS insensitive to BCR inhibition. This OXPHOShigh-BCRlow transcriptional axis of RT can be exploited therapeutically. Conclusions: These findings demonstrate the early seeding of subclones driving advanced stages of cancer evolution and uncover therapeutic targets for the, once expanded, lethal Richter transformation. Citation Format: Ferran Nadeu, Romina Royo, Ramon Massoni-Badosa, Beatriz Garcia-Torre, Martí Duran-Ferrer, Kevin J. Dawson, Marta Kulis, Ander Diaz-Navarro, Neus Villamor, Juan L. Melero, Vicente Chapaprieta, Ana Dueso-Barroso, Julio Delgado, Riccardo Moia, Sara Ruiz-Gil, Domenica Marchese, Núria Verdaguer-Dot, Mónica Romo, Maria Rozman, Gerard Frigola, Alfredo Rivas-Delgado, Tycho Baumann, Miguel Alcoceba, Marcos González, Fina Climent, Pau Abrisqueta, Josep Castellví, Francesc Bosch, Marta Aymerich, Anna Enjuanes, Sílvia Ruiz-Gaspà, Armando López-Guillermo, Pedro Jares, Sílvia Beà, Dolors Colomer, Núria López-Bigas, Josep LlGelpí, David Torrents, Peter J. Campbell, Ivo Gut, Pablo M. Garcia-Roves, Davide Rossi, Gianluca Gaidano, Xose S. Puente, Holger Heyn, Francesco Maura, José I. Martín-Subero, Elías Campo. Early seeding of Richter transformation in chronic lymphocytic leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3795.

Cationic antimicrobial peptide NRC-03 induces oral squamous cell carcinoma cell apoptosis via CypD-mPTP axis-mediated mitochondrial oxidative stress

Pleurocidin-family cationic antimicrobial peptide NRC-03 exhibits potent and selective cytotoxicity towards cancer cells. However, the anticancer effect of NRC-03 in oral squamous cell carcinoma (OSCC) and the molecular mechanism of NRC-03 induced cancer cell death is still unclear. This study focused to investigate mitochondrial oxidative stress-mediated altered mitochondrial function involved in NRC-03-induced apoptosis of OSCC cells. NRC-03 entered the OSCC cells more easily than that of normal cells and bound to mitochondria as well as the nucleus, causing cell membrane blebbing, mitochondria swelling, and DNA fragmentation. NRC-03 induced high oxygen consumption, reactive oxygen species (ROS) release, mitochondrial dysfunction, and apoptosis in OSCC cells. Non-specific antioxidant N-acetyl-l-cysteine (NAC), or mitochondria-specific antioxidant mitoquinone (MitoQ) alleviated NRC-03-induced apoptosis and mitochondrial dysfunction indicated that NRC-03 exerts a cytotoxic effect in cancer cells via inducing cellular and mitochondrial oxidative stress. Moreover, the expression of cyclophilin D (CypD), the key component of mitochondrial permeability transition pore (mPTP), was upregulated in NRC-03-treated cancer cells. Blockade of CypD by siRNA-mediated depletion or pharmacological inhibitor cyclosporine A (CsA) significantly suppressed NRC-03-induced mitochondrial oxidative stress, mitochondrial dysfunction, and apoptosis. NRC-03 also activated MAPK/ERK and NF-κB pathways. Importantly, intratumoral administration of NRC-03 inhibited the growth of CAL-27 cells-derived tumors on xenografted animal models. Taken together, our study indicates that NRC-03 induces apoptosis in OSCC cells via the CypD-mPTP axis mediated mitochondrial oxidative stress.

Hydrocarbon exposure effect on energetic metabolism and immune response in Crassostrea virginica

Crassostrea virginica was exposed to different light crude oil levels to assess the effect on transcriptomic response and metabolic rate. The exposure time was 21 days, and levels of 100 and 200 μg/L were used, including a control. The most significant difference among treatments was the overexpression of several genes associated with energy production, reactive oxygen species (ROS) regulation, immune system response, and inflammatory response. Also, a hydrocarbon concentration-related pattern was identified in ROS regulation, with a gene expression ratio near 1.8:1 between 200 and 100 μg/L treatments. Statistical analysis showed no interaction effect for metabolic rate; however, significant differences were found for oil concentration and time factors, with a higher oxygen consumption at 200 μg/L. Our findings provide novel information about the metabolic response of C. virginica during hydrocarbons exposure. In addition, our results point out which biological processes should be investigated as targets for searching bioindicators.

Ignition and combustion of boron particles coated by modified materials with various action mechanisms

Coating boron particles with materials having multiple mechanisms of action is a promising way to promote the ignition and combustion properties of boron. The differences in thermal oxidation properties and ignition combustion characteristics of micron-sized boron composite particles (namely, AP@B, FR@B, and GAP@B) coated with 20 wt% ammonium perchlorate (AP), fluoropolymer (FR), or glycidyl azide polymer (GAP) were comparatively investigated using TG–DSC and CO2 laser ignition test systems. The results showed that the starting reaction temperature and activation energy of the composite particles were significantly reduced by the lower pyrolysis temperatures of the three modified materials. However, their oxidation phase lagged behind that of the original boron particles, most likely because the coating agglomerated 27% of the fine boron particles (<0.1 μm) into micron-sized particles. In addition, the slow heating approach did not allow the particles to reach the ignition temperature immediately and may indirectly aggravate the oxide layer thickness. Nevertheless, the coating modifier effectively promoted energy release (the heat release was increased by 93.76%, 28.65%, and 24.20% for FR@B, GAP@B, and AP@B, respectively). Generally, the ignition delay time (ti) decreases, whereas the combustion time (tc), self-sustaining combustion time (tf), maximum combustion temperature (Tmax) and burnout rate (α) increase after the coating of modified materials. First, AP decomposition produced O2 and other gases to provide an oxidant for boron combustion and disperse the particles into space, which promotes extremely rapid energy release. Thus, the Tmax and α of AP@B were significantly enhanced. Second, FR pyrolysis gas production can vaporize B2O3 and then promote the exposure of internal boron to react with oxygen. Thus, the tf and α of FR@B were significantly enhanced. However, the Tmax value was not the highest since the highest calorific value (up to 15,094 J•g−1) of FR@B is released at a slow rate. Finally, GAP can significantly shorten ti due to its lower activation energy, and this modification effect can be significantly improved by increasing the O2 content. Since boron is characterized by high oxygen consumption, increasing the oxygen partial pressure can significantly promote ignition and combustion. The Tmax values of four samples in a mixed O2–N2 environment under 1.0 MPa even exceeded the boiling point of B2O3, which is favorable for the reaction of internal boron with oxygen due to the gasification of the oxide layer at this time.

Genetic and genomic analysis of oxygen consumption in mice.

We estimated genetic parameters for oxygen consumption (OC), OC per metabolic body weight (OCMBW) and body weight at three through 8 weeks of age in divergently selected mice populations, with an animal model considering maternal genetic, common litter environmental and cytoplasmic inheritance effects. Cytoplasmic inheritance was considered based on maternal lineage information. With respect to OC, estimated direct heritability was moderate (0.32) and the estimated proportion of the variance of cytoplasmic inheritance effects to the phenotypic variance was very low (0.01), implying that causal genes for OC could be located on autosomes. To assess this hypothesis, we attempted to identify possible candidate causal genes through selective signature detection with the results of pooled whole-genome resequencing using pooled DNA samples from high and low OC mice. We made a list of possible candidate causal genes for OC, including those relating to electron transport chain and ATP-binding proteins (Ndufa12, Sdhc, Atp10b, etc.), Prr16 encoding Largen protein, Cry1 encoding a key component of the circadian core oscillator and so on. The results, although careful interpretation must be required, could contribute to elucidate the genetic mechanism of OC, an indicator for maintenance energy requirement, and therefore feed efficiency.

Endosulfan causes oxidative stress in the liver and brain that involves inhibition of NADH dehydrogenase and altered antioxidant enzyme status in rat

Endosulfan, a neurotoxic, highly persistent organochlorine insecticide, is known for its acute and chronic toxicity. We have shown that a single sublethal dose of endosulfan caused high induction of oxidative stress in the liver and brain by altering the antioxidant status, as shown by reduction in the antioxidant enzymes SOD, GPx, GST, GR along with increased ROS and lipid peroxidation. The cerebral region in the brain showed a higher level of oxidative stress than the cerebellum, revealing differential sensitivity of the brain regions to endosulfan. Depletion of natural antioxidants causes the imbalance of redox status in cells, and the role of mitochondrial distress causally related to the cellular oxidative stress in vivo is not well understood. We have shown that reduction in the mitochondrial NADH dehydrogenase activity in the brain is associated with the induction of ROS in endosulfan-treated rats. Although oxidative stress is induced in both the liver and brain, the oxidative damage to the brain has implications for the toxic outcome in view of the brain's lower antioxidant defenses and high oxygen consumption.

Thermal operation of superlayer space in Romelt furnace

From the point of metallurgical heat engineering, the Romelt process is promising for processing industrial waste, poor ores and secondary metals without their preliminary preparation and the use of coke. But one of the main disadvantages of this process is high specific consumption of oxygen and fuel for the production of 1 ton of primary metal. The peculiarity of the Romelt process is that the main amount of heat required for implementation of the technological process is supplied to the bubbling layer from the superlayer space due to afterburning of the exhaust gases with technical oxygen. Heat transfer is carried out by a radiation-convective mechanism. Any changes in the afterburning process are possible, if they do not entail an unacceptable change in temperature in combustion zone. In the work, a study was conducted to reduce the specific oxygen consumption per 1 ton of primary metal, based on the data of melting a mixture of blast furnace and converter slurries for pig iron. The authors studied the possibility of reducing the specific oxygen consumption supplied to the superlayer space of the furnace for afterburning gases leaving the bubbling layer during the Romelt process. When using blast heating supplied to the lower tuyeres and oxygen heating supplied to the afterburning zone, it is possible to reduce the specific oxygen consumption per 1 ton of cast iron by 11 % without reducing the furnace performance. In the afterburning zone, it is recommended to use oxygen heated up to 400 °C in the recuperator with simultaneous supply of a blast heated up to 600 °C to the lower tuyeres.

Right ventricular myocardial energetic model for evaluating right heart function in pulmonary arterial hypertension.

BackgroundPulmonary arterial hypertension (PAH) increases right ventricular (RV) workload and decreases myocardial oxygen reserve, eventually leading to poor cardiac output. This study created and assessed a novel model of RV work output based on RV hemodynamics and oxygen supply, allowing new insight into causal mechanisms of RV dysfunction.MethodsThe RV function model was built upon an earlier, left ventricular model and further adjusted for more accurate clinical use. The model assumes that RV total power output (1) is the sum of isovolumic and stroke power and (2) is linearly related to its right coronary artery oxygen supply. Thus, when right coronary artery flow is limited or isovolumic power is elevated, less energy is available for producing cardiac output. The original and adjusted models were validated via data from patients with idiopathic PAH (n = 14) and large animals (n = 6) that underwent acute pulmonary banding with or without hypoxia.ResultsBoth models demonstrated strong, significant correlations between RV oxygen consumption rate and RV total power output for PAH patients (original model, R 2 = 0.66; adjusted model, R 2 = 0.78) and sheep (original, R 2 = 0.85; adjusted, R 2 = 0.86). Furthermore, the models demonstrate a significant inverse relationship between required oxygen consumption and RV efficiency (stroke power/total power) (p < 0.001). Lastly, higher NYHA class was indicative of lower RV efficiency and higher oxygen consumption (p = 0.013).ConclusionRight ventricular total power output can be accurately estimated directly from pulmonary hemodynamics and right coronary perfusion during PAH. This model highlights the increased vulnerability of PAH patients with compromised right coronary flow coupled with high afterload.

Flexible Thermal Sensitivity of Mitochondrial Oxygen Consumption and Substrate Oxidation in Flying Insect Species.

Mitochondria have been suggested to be paramount for temperature adaptation in insects. Considering the large range of environments colonized by this taxon, we hypothesized that species surviving large temperature changes would be those with the most flexible mitochondria. We thus investigated the responses of mitochondrial oxidative phosphorylation (OXPHOS) to temperature in three flying insects: the honeybee (Apis mellifera carnica), the fruit fly (Drosophila melanogaster) and the Colorado potato beetle (Leptinotarsa decemlineata). Specifically, we measured oxygen consumption in permeabilized flight muscles of these species at 6, 12, 18, 24, 30, 36, 42 and 45°C, sequentially using complex I substrates, proline, succinate, and glycerol-3-phosphate (G3P). Complex I respiration rates (CI-OXPHOS) were very sensitive to temperature in honeybees and fruit flies with high oxygen consumption at mid-range temperatures but a sharp decline at high temperatures. Proline oxidation triggers a major increase in respiration only in potato beetles, following the same pattern as CI-OXPHOS for honeybees and fruit flies. Moreover, both succinate and G3P oxidation allowed an important increase in respiration at high temperatures in honeybees and fruit flies (and to a lesser extent in potato beetles). However, when reaching 45°C, this G3P-induced respiration rate dropped dramatically in fruit flies. These results demonstrate that mitochondrial functions are more resilient to high temperatures in honeybees compared to fruit flies. They also indicate an important but species-specific mitochondrial flexibility for substrate oxidation to sustain high oxygen consumption levels at high temperatures and suggest previously unknown adaptive mechanisms of flying insects’ mitochondria to temperature.

The Role of Oxidative Stress in Skeletal Muscle Myogenesis and Muscle Disease.

The contractile activity, high oxygen consumption and metabolic rate of skeletal muscle cause it to continuously produce moderate levels of oxidant species, such as reactive oxygen species (ROS) and reactive nitrogen species (RNS). Under normal physiological conditions, there is a dynamic balance between the production and elimination of ROS/RNS. However, when the oxidation products exceed the antioxidant defense capacity, the body enters a state of oxidative stress. Myogenesis is an important process to maintain muscle homeostasis and the physiological function of skeletal muscle. Accumulating evidence suggests that oxidative stress plays a key role in myogenesis and skeletal muscle physiology and pathology. In this review, we summarize the sources of reactive oxygen species in skeletal muscle and the causes of oxidative stress and analyze the key role of oxidative stress in myogenesis. Then, we discuss the relationship between oxidative stress and muscle homeostasis and physiopathology. This work systematically summarizes the role of oxidative stress in myogenesis and muscle diseases and provides targets for subsequent antioxidant therapy and repair of inflammatory damage in noninflammatory muscle diseases.

Dysfunctional breathing diagnosed by cardiopulmonary exercise testing in 'long COVID' patients with persistent dyspnoea.

Background‘Long COVID’-associated dyspnoea may persist for months after SARS-CoV-2 infection. Among the causes of persistent dyspnoea, dysfunctional breathing (DB), defined as an erratic or inappropriate ventilation at rest or exercise, has been observed, but little is known about its occurrence and pathophysiology among individuals with ‘long COVID’. We aimed to describe the occurrence and identify clinical predictors of DB among patients following SARS-CoV-2 infection.MethodsCardiopulmonary exercise testing (CPET) was performed in 51 SARS-CoV-2 patients (median age, 64 years (IQR, 15)); male, 66.7%) living with ‘long COVID’ and persistent dyspnoea. CPET was classified into three dominant patterns: respiratory limitation with gas exchange abnormalities (RL); normal CPET or O2 delivery/utilisation impairment (D); and DB. Non-parametric and χ2 tests were applied to analyse the association between CPET dominant patterns and demographics, pulmonary function tests and SARS-CoV-2 severity.ResultsAmong 51 patients, DB mostly without hyperventilation was found in 29.4% (n=15), RL in 54.9% (n=28) and D in 15.7% (n=8). When compared with RL individuals, patients with DB were younger, had significantly less severe initial infection, a better transfer capacity for carbon monoxide (median 85% (IQR, 28)), higher oxygen consumption (22.9 mL/min/kg (IQR, 5.5)), a better ventilatory efficiency slope (31.6 (IQR, 12.8)), and a higher SpO2 (95% (IQR, 3)).ConclusionsOur findings suggest that DB without hyperventilation could be an important pathophysiological mechanism of disabling dyspnoea in younger outpatients following SARS-CoV-2 infection, which appears to be a feature of COVID-19 not described in other viral diseases.

Aldehyde replacement advances efficient hydrogen production in electrolyser

The high energy consumption and production of undesired oxygen greatly restrict the wide adoption of water electrolysis for hydrogen production. In a paper recently published in Nature Catalysis, Wang and coworkers rationally introduce aldehydes for oxidation at anode to replace oxygen evolution reaction, which can produce hydrogen and value-added products at low potential, realizing efficient bipolar hydrogen production with high-purity. Moreover, these aldehydes are biomass-derived and contribute to sustainable hydrogen production.

Factores ambientales condicionantes del metabolismo de una laguna pampeana

Pampean shallow lakes naturally have water nitrogen and phosphorous concentrations that allow the development of dense beds of submerged aquatic vegetation, phytoplankton, or free-floating aquatic plants. In recent years, the eutrophication of these shallow lakes has increased due to the intensification of agriculture, use of fertilization and livestock. Phytoplankton- induced turbidity inhibits the growth of the submerged aquatic vegetation leading to phytoplankton dominance. This is the case of the Lobos shallow lake, which in a period greater than 20 years has remained as an organic turbid shallow lake, with cyanobacteria dominance. The study of the ecosystem metabolism can give relevant information about how the trophic state of a shallow lake drives production, respiration and net metabolism, and the potential consequences for aquatic biota. We evaluated the Lobos shallow lake metabolism using diel changes in dissolved oxygen concentrations during autumn and spring. Gross primary production showed lower values and variability in Autumn (1.57±1.33 g O2.m-2.día-1) than in Spring (20.45±18.00 g O2.m-2.día-1). Although there was high production during the day, respiration was also high, especially in Spring, where there was higher density of planktonic organisms principally cyanobacteria, exceeding net production in both seasons. Thus, we found mainly low or negative values for the net metabolism in Lobos shallow lake. A high oxygen consumption occurred during spring and at the lowest depth, coinciding with the highest chlorophyll-a concentrations, particulate matter, and lowest water transparency. We conclude that Lobos shallow lake was predominantly heterotrophic during study period. High nutrient concentrations will likely increase the factors that produce stress and negative impacts on aquatic fauna.

Oxidative status of planarians is differently affected by PAHs: 3-5 Benzene ring compounds

Planarians are promising model animals and are increasing in importance for ecotoxicological studies. However, there is scarce to no information regarding polycyclic aromatic hydrocarbons (PAHs) specific toxicity towards planarians at the biochemical level. We aimed to uncover how vital physiological functions, such as, neurophysiology, detoxification and oxidative stress status, and cellular energy allocation are affected on the freshwater planarian Girardia tigrina by low and high molecular weight PAHs – phenanthrene, pyrene and benzo[a]pyrene (B[a]P). Phenanthrene affected planarian antioxidant defences and detoxification, increasing glutathione levels and activity of glutathione-S-transferase (GST), the latter in a dose-dependent way (from 75 to 300 µg L−1). Phenanthrene also decreased carbohydrates in planarians exposed to 150 and 300 µg L−1. Pyrene caused higher oxygen consumption and decreased energy budget in planarians exposed to 75 and 150 µg L−1. B[a]P exposure decreased G. tigrina GST activity in a dose-dependent way. Lower lipid peroxidation levels were measured in planarians exposed to 2.5 and 75 µg L−1 of pyrene and at 37.5, 75 and 150 µg L−1 of B[a]P. The present data indicate that each of these PAHs seems to elicit distinct biochemical responses in planarians, possibly pointing to different biochemical interactions and/or metabolisation of each compound, with B[a]P causing the most severe effects.

Exploring the effects of artesunate and fuzheng huayu decoction on mitochondria in the treatment of schistosomiasis liver fibrosis

Objective: To compare the effects of artesunate (Art) and fuzheng huayu decoction on mitochondrial autophagy in the treatment of schistosomiasis liver fibrosis. Methods: Eighty C57BL/6 female mice were randomly divided into healthy control group, infection group, Art treatment group and Fuzheng Huayu Decoction treatment group, with 20 mice in each group. Mice in the infection group and treatment group were infected with 16 Schistosoma japonicum cercariae. After 6 weeks, praziquantel (300 mg/kg) was used for 2 days to kill the worms. The Art treatment group was treated with intraperitoneal injection of 100 mg/kg/day, while the Fuzheng Huayu Decoction treatment group was fed 16g of fuzheng huayu decoction per 1kg per day. After 6 weeks, fresh liver tissues of the four groups were collected. Masson staining and Western blot were used to observe the succinate dehydrogenase subunit A (SDHA) and malate dehydrogenase (MDH2), citrate synthase (CS), ketoglutarate dehydrogenase (OGDH), and target of rapamycin 1 (mTORC1) pathway involved in mitochondrial tricarboxylic acid cycle in liver tissues. The relative expression levels of adenylate activated protein kinase (AMPK) and mitochondrial autophagy pathway kinase (PINK1) were detected. Liver tissue samples were extracted from each group to detect the mitochondrial oxygen consumption rate. Two-way ANOVA was used to compare the significance and difference between two sets of samples. Results: Masson staining showed that the infection group mice had significantly higher liver fibrosis area than the healthy control group, while the Art treatment group and Fuzheng Huayu Decoction treatment group mice had lower liver fibrosis area than the infection group. Western blot analysis showed that the infection group (0.82 ± 0.05) had significantly lower relative expression of SDHA protein than the healthy control group (1.00 ± 0.05) (t = 11.23, P = 0.0035), while the Art treatment group (0.73 ± 0.05) had significantly higher relative expression of SDHA protein than the infection group (t = 10.79, P = 0.0073). However, there was no significant change in Fuzheng Huayu Decoction treatment group (0.98±0.05) (t = 1.925, P = 0.1266). The relative expression of p-AMPK protein was significantly higher in the infection group (1.15 ±0.05) than in the healthy control group (0.98 ± 0.07, t = 12.18, P = 0.0029), and the expression of p-AMPK in the Art treatment group (0.50 ± 0.05) was significantly lower than the infection group (t = 11.78, P = 0.0032). The relative protein expression of AMPK was significantly lower in the infection group (0.80 ± 0.05) than in the healthy control group (1.00 ± 0.05, t = 10.53, P = 0.0046). The expression of AMPK was significantly lower in the Art treatment group (0.54 ± 0.05) than in the infection group (T = 13.98, P = 0.0036). The relative expression of p-mTORC1 protein (0.93 ± 0.08) was not significantly different in the infection group than in the healthy control group (t = 2.28, P = 0.065), while the Art treatment group (0.63 ± 0.05) had significantly lower relative expression of p-mTORC1 protein than the infection group (t = 10.58, P = 0.029). The expression of p-mTORC1/ m-TORC1 was not significantly different in the infection group (0.98 ± 0.03) than in the healthy control group (0.97 ± 0.03, t = 0.98, P = 0.085), while the Art treatment group (0.63 ± 0.05) had significantly lower relative expression of p-mTORC1/ m-TORC1 than the infection group (t = 14.58, P = 0. 009). The relative protein expression of PINK1 was significantly lower in the infection group (0.55 ± 0.05) than in the healthy control group (1.00 ± 0.03, t = 13.49, P = 0.0011), while the Art treatment group (1.21 ± 0.05, t = 9.98, P = 0.0046) and Fuzheng Huayu Decoction treatment group (1.31 ±0.35, t = 6.98, P = 0.027) had significantly higher relative protein expression of PINK1 than the infection group. Mitochondrial function tests showed that after adding substrate complex II, the oxygen consumption of the infection group was lower than the healthy control group, while the Art treatment group and the Fuzheng Huayu Decoction treatment group had higher oxygen consumption than the infection group. The oxygen consumption was significantly lower after adding the substrate complex III in the infection group than the healthy control group, while the Art treatment group and Fuzheng Huayu Decoction treatment group had higher oxygen consumption than the infection group. Conclusion: Art can alleviate schistosomiasis liver fibrosis by inhibiting AMPK/mTORC1 signaling pathway activity and enhancing mitochondrial oxygen consumption, autophagy and SDHA expression.

Irradiation Causes Alterations of Polyamine, Purine, and Sulfur Metabolism in Red Blood Cells and Multiple Organs.

Investigating the metabolic effects of radiation is critical to understand the impact of radiotherapy, space travel, and exposure to environmental radiation. In patients undergoing hemopoietic stem cell transplantation, iron overload is a common risk factor for poor outcomes. However, no studies have interrogated the multiorgan effects of these treatments concurrently. Herein, we use a model that recapitulates transfusional iron overload, a condition often observed in chronically transfused patients. We applied an omics approach to investigate the impact of both the iron load and irradiation on the host metabolome. The results revealed dose-dependent effects of irradiation in the red blood cells, plasma, spleen, and liver energy and redox metabolism. Increases in polyamines and purine salvage metabolites were observed in organs with high oxygen consumption including the heart, kidneys, and brain. Irradiation also impacted the metabolism of the duodenum, colon, and stool, suggesting a potential effect on the microbiome. Iron infusion affected the response to radiation in the organs and blood, especially in erythrocyte polyamines and spleen antioxidant metabolism, and affected glucose, methionine, and glutathione systems and tryptophan metabolism in the liver, stool, and the brain. Together, the results suggest that radiation impacts metabolism on a multiorgan level with a significant interaction of the host iron status.

Local pH and oxygen concentration at the interface of Zn alloys in Tris-HCl or HEPES buffered Hanks’ balanced salt solution

Although Tris-HCl and HEPES are typically used pH buffers for in vitro studies, they are recently proven to be unable to stabilize local pH at Mg interface in simulated body fluids. In this study, local pH close to physiological (7.1–7.5) was found at metal/fluid interface of pure Zn, Zn-0.8 wt%Ca and Zn-0.8 wt%Mg alloys in Tris-HCl or HEPES buffered Hanks’ balanced salt solution (HBSS) at 37 °C under hydrodynamic conditions. High rate oxygen consumption was detected above Zn alloys in various HBSS electrolytes. These findings support the previous recommendation of using synthetic pH buffers for in vitro studies of biodegradable Zn-based alloys.

Environmental drivers and sources of stream oxygen consumption in an agricultural lake catchment

The combination of ongoing climate change and the historical loss of streams and wetland areas have presented new ecological challenges. These challenges became evident during a massive fish kill in Lake Fil, Denmark, in August 2018. We know that high amounts of labile organic matter entered the lake after a particularly heavy rainfall that followed a long period of heat and drought. Bacteria decomposed the organic matter, resulting in a quickly deoxygenated lake and an extensive fish kill. However, we do not know whether there is spatial variation in the amount of transportable labile matter across the catchment area. Identifying catchment ‘hotspots’ that sustain particularly high oxygen consumption rates will help managers to pursue interventions that can promote a high ecological quality of Lake Fil and its catchment. The method we developed to identify hotspots can be used by practitioners everywhere to prepare for and mitigate events similar to the 2018 disaster at Lake Fil. To identify hotspots in the stream network that feeds into Lake Fil, we measured oxygen consumption rates and environmental variables at 13 sites on five occasions. We found that oxygen consumption rates varied 2–16-fold between sites and 2–13-fold between sampling days. Oxygen consumption rates were positively related to the concentration of tryptophan-like material and ammonium but negatively related to the complexity of humic substances. Together, these variables accounted for 65% of the variation in the oxygen consumption rate across sub-catchments. High levels of tryptophan-like material and dissolved nutrients derive from intensive agricultural land use in the catchment. However, all oxygen consumption rates measured in this paper were apparently lower than those during the fish kill of August 2018, when the catchment fed higher concentrations of labile organic matter into the lake. The risk of anoxic water and fish kills can be mitigated by reducing and dispersing the input of labile organic matter following shifting periods of drought and heavy rain, which can be done by creating wetlands in the stream network or by implementing biogas facilities, thereby reducing pulses of organic matter and nutrients entering the stream.

Identification of Candidate Genes Associated With Hypoxia Tolerance in Trachinotus blochii Using Bulked Segregant Analysis and RNA-Seq.

Golden Pompano (Trachinotus blochii) has rapidly developed into the one of the main valuable fish species in Chinese marine aquaculture. Due to its rapid growth, active metabolism, and high oxygen consumption, hypoxia will increase its mortality and cause serious economic losses. We constructed two experimental groups of fish with different degrees of tolerance to hypoxia, used BSR-Seq analysis based on genome and genetic linkage groups to locate SNPs and genes that were related to the differences in hypoxia tolerance. The results showed that hypoxia tolerance SNPs of golden pompano may be jointly determined by multiple linkage groups, especially linkage groups 18 and 22. There were 768 and 348 candidate genes located in the candidate regions of the brain and liver, respectively. These genes were mainly involved in anaerobic energy metabolism, stress response, immune response, waste discharge, and cell death. The prostaglandin-endoperoxide synthase 2 (PTGS2) on LG8, which is involved in the metabolism of arachidonic acid, has a G/A nonsynonymous mutation at position 20641628, and the encoded amino acid was changed from hydrophobic aspartic acid to asparaginate. The specific pathway of the RIG-I-like receptor signaling pathway in the liver may mediate the metabolic system and the immune system, linking glucose metabolism with immune regulation. The death of the hypoxia-intolerant group may be due to the accumulation of lactic acid caused by the activation of anaerobic glycolysis during the early stage of hypoxia stress, and the activation of type I interferon was inhibited, which resulted in decreased immunity. Among the genes involved in the RIG-I-like receptor signaling pathway, the CYLD Lysine 63 Deubiquitinase (CYLD) located on LG16 had a G/T nonsynonymous mutation at position 13629651, and the encoded amino acid was changed from alanine acid to valine. The interferon induced with helicase C domain 1 (Ifih1) located on LG18 has a G/C nonsynonymous mutation at position 16153700, and the encoded hydrophilic glycine was changed to hydrophobic alanine. Our findings suggest these SNPs may assist in the molecular breeding of hypoxia-tolerant golden pompano, and speculate that the balance of glucose and lipid metabolism plays a key role in Trachinotus blochii under acute hypoxia.