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Proceedings. Biological Sciences Jun 2024Hyperoxia has been shown to expand the aerobic capacity of some fishes, although there have been very few studies examining the underlying mechanisms and how they vary...
Hyperoxia has been shown to expand the aerobic capacity of some fishes, although there have been very few studies examining the underlying mechanisms and how they vary across different exposure durations. Here, we investigated the cardiorespiratory function of yellowtail kingfish () acutely (~20 h) and chronically (3-5 weeks) acclimated to hyperoxia (~200% air saturation). Our results show that the aerobic performance of kingfish is limited in normoxia and increases with environmental hyperoxia. The aerobic scope was elevated in both hyperoxia treatments driven by a ~33% increase in maximum O uptake (MO), although the mechanisms differed across treatments. Fish acutely transferred to hyperoxia primarily elevated tissue O extraction, while increased stroke volume-mediated maximum cardiac output was the main driving factor in chronically acclimated fish. Still, an improved O delivery to the heart in chronic hyperoxia was not the only explanatory factor as such. Here, maximum cardiac output only increased in chronic hyperoxia compared with normoxia when plastic ventricular growth occurred, as increased stroke volume was partly enabled by an ~8%-12% larger relative ventricular mass. Our findings suggest that hyperoxia may be used long term to boost cardiorespiratory function potentially rendering fish more resilient to metabolically challenging events and stages in their life cycle.
Topics: Animals; Perciformes; Oxygen Consumption; Hyperoxia; Acclimatization; Oxygen; Cardiac Output
PubMed: 38889794
DOI: 10.1098/rspb.2023.2557 -
Biology Open Jun 2024Zebrafish have become a widely used vertebrate model in physiology and reliable measures of their metabolic rate are needed. We have developed a 3D-printed respirometer...
Zebrafish have become a widely used vertebrate model in physiology and reliable measures of their metabolic rate are needed. We have developed a 3D-printed respirometer and swim tunnel system and used it for obtaining accurate measurement of standard metabolic rate (SMR) and maximal, aerobic metabolic rate (MMR) in zebrafish under rest and maximal exercise, respectively. We compared a slow (stepwise) protocol to a fast (continuous) protocol for determining MMR. The fast protocol yielded slightly (but not significantly) higher oxygen consumption rates than the slow protocol and the data, in contrast to the slow protocol, followed a normal distribution. These findings point to the fast protocol as a fast and reliable method for obtaining accurate values of MMR in zebrafish. We make the 3D drawings for printing the system available to researchers, to help streamline the field of metabolic research in zebrafish and other smaller fish species.
Topics: Zebrafish; Animals; Printing, Three-Dimensional; Oxygen Consumption; Swimming; Energy Metabolism; Basal Metabolism
PubMed: 38887971
DOI: 10.1242/bio.060375 -
Tobacco Induced Diseases 2024In this study, we investigate the effects of smoking on pain scores, vital signs, and analgesic consumption in the intraoperative and postoperative period in patients...
INTRODUCTION
In this study, we investigate the effects of smoking on pain scores, vital signs, and analgesic consumption in the intraoperative and postoperative period in patients undergoing tympanomastoidectomy surgery.
METHODS
A total of 100 patients with American Society of Anesthesiologists I-II status, aged 18-55 years, and who were planned to undergo tympanomastoidectomy surgery were divided into two groups: smokers (Group 1) and non-smokers (Group 2). The patients were compared for preoperative, intraoperative, and 24-hour postoperative carboxyhemoglobin, blood pressure, oxygen saturation, respiratory rate, heart rate, pain intensity and verbal numerical rating scales, the extent of patient-controlled tramadol dose, nausea, and vomiting.
RESULTS
There were 50 individuals in each group. Postoperative analgesic consumption and pain scores were higher in Group 1, and the first postoperative pain was felt earlier. Furthermore, in Group 1, preoperative carboxyhemoglobin levels and postoperative nausea were statistically higher before, after, and at the tenth minute after induction, whereas oxygen saturation was lower. The two groups had no statistical difference regarding intraoperative and postoperative vital signs. Postoperative analgesic consumption was not affected by age or gender.
CONCLUSIONS
Smoking changes postoperative pain management, especially for this kind of operation, and these patients feel more pain and need more postoperative analgesic doses. Therefore, effective postoperative pain control should take account of smoking behavior, and analgesic doses may need to be adjusted for patients who smoke.
PubMed: 38887600
DOI: 10.18332/tid/189301 -
Burns & Trauma 2024Due to vasculature injury and increased oxygen consumption, the early wound microenvironment is typically in a hypoxic state. We observed enhanced cell migration ability...
BACKGROUND
Due to vasculature injury and increased oxygen consumption, the early wound microenvironment is typically in a hypoxic state. We observed enhanced cell migration ability under early short-term hypoxia. CCL2 belongs to the CC chemokine family and was found to be increased in early hypoxic wounds and enriched in the extracellular signal-regulated kinase (ERK)1/2 pathway in our previous study. However, the underlying mechanism through which the CCL2-ERK1/2 pathway regulates wound healing under early short-term hypoxia remains unclear. Activation of epithelial-mesenchymal transition (EMT) is a key process in cancer cell metastasis, during which epithelial cells acquire the characteristics of mesenchymal cells and enhance cell motility and migration ability. However, the relationship between epithelial cell migration and EMT under early short-term hypoxia has yet to be explored.
METHODS
HaCaT cells were cultured to verify the effect of early short-term hypoxia on migration through cell scratch assays. Lentiviruses with silenced or overexpressed CCL2 were used to explore the relationship between CCL2 and migration under short-term hypoxia. An acute full-thickness cutaneous wound rat model was established with the application of an ERK inhibitor to reveal the hidden role of the ERK1/2 pathway in the early stage of wound healing. The EMT process was verified in all the above experiments through western blotting.
RESULTS
In our study, we found that short-term hypoxia promoted cell migration. Mechanistically, hypoxia promoted cell migration through mediating CCL2. Overexpression of CCL2 via lentivirus promoted cell migration, while silencing CCL2 via lentivirus inhibited cell migration and the production of related downstream proteins. In addition, we found that CCL2 was enriched in the ERK1/2 pathway, and the application of an ERK inhibitor and verified the upstream and downstream relationships between the CCL2 pathway and ERK1/2. Western blot results both and demonstrated that early short-term hypoxia promotes epidermal cell migration by activating the CCL2-ERK1/2 pathway and EMT during wound healing.
CONCLUSIONS
Our work demonstrated that hypoxia in the early stage serves as a stimulus for triggering wound healing through activating the CCL2-ERK1/2 pathway and EMT, which promote epidermal cell migration and accelerate wound closure. These findings provide additional detailed insights into the mechanism of wound healing and new targets for clinical treatment.
PubMed: 38887221
DOI: 10.1093/burnst/tkae017 -
Deletion of endothelial IGFBP5 protects against ischaemic hindlimb injury by promoting angiogenesis.Clinical and Translational Medicine Jun 2024Angiogenesis is critical for forming new blood vessels from antedating vascular vessels. The endothelium is essential for angiogenesis, vascular remodelling and...
BACKGROUND
Angiogenesis is critical for forming new blood vessels from antedating vascular vessels. The endothelium is essential for angiogenesis, vascular remodelling and minimisation of functional deficits following ischaemia. The insulin-like growth factor (IGF) family is crucial for angiogenesis. Insulin-like growth factor-binding protein 5 (IGFBP5), a binding protein of the IGF family, may have places in angiogenesis, but the mechanisms are not yet completely understood. We sought to probe whether IGFBP5 is involved in pathological angiogenesis and uncover the molecular mechanisms behind it.
METHODS AND RESULTS
IGFBP5 expression was elevated in the vascular endothelium of gastrocnemius muscle from critical limb ischaemia patients and hindlimb ischaemic (HLI) mice and hypoxic human umbilical vein endothelial cells (HUVECs). In vivo, loss of endothelial IGFBP5 (IGFBP5) facilitated the recovery of blood vessel function and limb necrosis in HLI mice. Moreover, skin damage healing and aortic ring sprouting were faster in IGFBP5 mice than in control mice. In vitro, the genetic inhibition of IGFBP5 in HUVECs significantly promoted tube formation, cell proliferation and migration by mediating the phosphorylation of IGF1R, Erk1/2 and Akt. Intriguingly, pharmacological treatment of HUVECs with recombinant human IGFBP5 ensued a contrasting effect on angiogenesis by inhibiting the IGF1 or IGF2 function. Genetic inhibition of IGFBP5 promoted cellular oxygen consumption and extracellular acidification rates via IGF1R-mediated glycolytic adenosine triphosphate (ATP) metabolism. Mechanistically, IGFBP5 exerted its role via E3 ubiquitin ligase Von Hippel-Lindau (VHL)-regulated HIF1α stability. Furthermore, the knockdown of the endothelial IGF1R partially abolished the reformative effect of IGFBP5 mice post-HLI.
CONCLUSION
Our findings demonstrate that IGFBP5 ablation enhances angiogenesis by promoting ATP metabolism and stabilising HIF1α, implying IGFBP5 is a novel therapeutic target for treating abnormal angiogenesis-related conditions.
Topics: Animals; Insulin-Like Growth Factor Binding Protein 5; Mice; Hindlimb; Humans; Human Umbilical Vein Endothelial Cells; Ischemia; Disease Models, Animal; Male; Neovascularization, Physiologic; Angiogenesis
PubMed: 38886900
DOI: 10.1002/ctm2.1725 -
Molecular Metabolism Jun 2024The transcriptional coactivator PGC-1α has been implicated in the regulation of multiple metabolic processes. However, the previously reported metabolic phenotypes of...
The transcriptional coactivator PGC-1α has been implicated in the regulation of multiple metabolic processes. However, the previously reported metabolic phenotypes of mice deficient in PGC-1α have been inconsistent. PGC-1α exists as multiple isoforms, including variants transcribed from an alternative first exon. We show here that alternative PGC-1α variants are the main entity that increases PGC-1α during exercise. These variants, unlike the canonical isoform of PGC-1α, are robustly upregulated in human skeletal muscle after exercise. Furthermore, the extent of this upregulation correlates with oxygen consumption. Mice lacking these variants manifest impaired energy expenditure during exercise, leading to the development of obesity and hyperinsulinemia. The alternative variants are also upregulated in brown adipose tissue in response to cold exposure, and mice lacking these variants are intolerant of a cold environment. Our findings thus indicate that an increase in PGC-1α expression, attributable mostly to upregulation of alternative variants, is pivotal for adaptive enhancement of energy expenditure and heat production and thereby essential for the regulation of whole-body energy metabolism.
PubMed: 38885788
DOI: 10.1016/j.molmet.2024.101968 -
PloS One 2024The human forearm model is commonly employed in physiological investigations exploring local vascular function and oxygen delivery; however, the effect of arm dominance...
The human forearm model is commonly employed in physiological investigations exploring local vascular function and oxygen delivery; however, the effect of arm dominance on exercising forearm hemodynamics and skeletal muscle oxygen saturation (SmO2) in untrained individuals is poorly understood. Therefore, the purpose of this study was to explore the effect of self-identified arm dominance on forearm hemodynamics and SmO2 in untrained individuals during submaximal, non-ischemic forearm exercise. Twenty healthy individuals (23±4 years, 50% female; 80% right-handed) completed three-minute bouts of supine rhythmic (1 second contraction: 2 second relaxation duty cycle) forearm handgrip exercise at both absolute (10kg; 98N) and relative (30% of maximal voluntary contraction) intensities in each forearm. Beat-by-beat measures of forearm blood flow (FBF; ml/min), mean arterial blood pressure (MAP; mmHg) and flexor digitorum superficialis SmO2 (%) were obtained throughout and averaged during the final 30 seconds of rest, exercise, and recovery while forearm vascular conductance was calculated (FVC; ml/min/100mmHg). Data are Δ from rest (mean±SD). Absolute force production did not differ between non-dominant and dominant arms (97±11 vs. 98±13 N, p = 0.606) whereas relative force production in females did (69±24 vs. 82±25 N, p = 0.001). At both exercise intensities, FBFRELAX, FVCRELAX, MAPRELAX, and the time constant tau for FBF and SmO2 were unaffected by arm dominance (all p>0.05). While arm dominance did not influence SmO2 during absolute intensity exercise (p = 0.506), the non-dominant arm in females experienced an attenuated reduction in SmO2 during relative intensity exercise (-14±10 vs. -19±8%, p = 0.026)-though exercise intensity was also reduced (p = 0.001). The present investigation has demonstrated that arm dominance in untrained individuals does not impact forearm hemodynamics or SmO2 during handgrip exercise.
Topics: Humans; Female; Muscle, Skeletal; Forearm; Hemodynamics; Male; Exercise; Adult; Young Adult; Hand Strength; Arm; Regional Blood Flow; Oxygen; Oxygen Consumption
PubMed: 38885214
DOI: 10.1371/journal.pone.0305539 -
Swiss Medical Weekly Jun 2024Anthracycline-based chemotherapy has well-known cardiotoxic effects, butmay also cause skeletal muscle myopathy and negatively affect cardiorespiratory fitness and... (Observational Study)
Observational Study
AIMS
Anthracycline-based chemotherapy has well-known cardiotoxic effects, butmay also cause skeletal muscle myopathy and negatively affect cardiorespiratory fitness and quality of life. The effectiveness of exercise training in improving cardiorespiratory fitness and quality of life during chemotherapy is highly variable. We set out to determine how the effect of exercise training on cardiorespiratory fitness (primary outcome) and quality of life (secondary outcome) in cancer patients is affected by the type of therapy they receive (cardiotoxic therapy with or without anthracyclines; non-cardiotoxic therapy) and the timing of the exercise training (during or after therapy).
METHODS
Consecutive patients with cancer who participated in an exercise-based cardio-oncology rehabilitation programme at a university hospital in Switzerland between January 2014 and February 2022 were eligible. Patients were grouped based on chemotherapy (anthracycline vs non-anthracycline) and timing of exercise training (during vs after chemotherapy). Peak oxygen uptake (VO2) was assessed with cardiopulmonary exercise testing (n = 200), and quality of life with the Functional Assessment of Cancer Therapies questionnaire (n = 77). Robust linear models were performed for change in peak VO2 including type and timing of cardiotoxic therapies, age, training impulse and baseline peak VO2; change in quality of life was analysed with cumulative linked models.
RESULTS
In all patients with valid VO2 (n = 164), median change in peak VO2 from before to after exercise training was 2.3 ml/kg/min (range: -10.1-15.9). The highest median change in peak VO2 was 4.1 ml/kg/min (interquartile range [IQR]: 0.7-7.7) in patients who completed exercise training during non-anthracycline cardiotoxic or non-cardiotoxic therapies, followed by 2.8 ml/kg/min (IQR: 1.2-5.3) and 2.3 ml/kg/min (IQR: 0.1-4.6) in patients who completed exercise training after anthracycline and after non-anthracycline cardiotoxic or non-cardiotoxic therapies, respectively. In patients who completed exercise training during anthracycline therapy, peak VO2 decreased by a median of -2.1 ml/kg/min (IQR: -4.7-2.0). In the robust linear model, there was a significant interaction between type and timing of cancer treatment for anthracycline therapy, with greater increases in peak VO2 when exercise training was performed after anthracycline therapy. For quality of life, higher baseline scores were negatively associated with changes in quality of life.
CONCLUSION
In our cohort, the increase in cardiorespiratory fitness was diminished when exercise training was performed concurrently with anthracyclines. For patients with cardiotoxic treatments other than anthracyclines, cardiorespiratory fitness and quality of life was not associated with timing of exercise training.
Topics: Humans; Male; Female; Cardiorespiratory Fitness; Quality of Life; Middle Aged; Anthracyclines; Longitudinal Studies; Neoplasms; Switzerland; Exercise Therapy; Exercise Test; Cardiac Rehabilitation; Cardiotoxicity; Time Factors; Aged; Oxygen Consumption
PubMed: 38885132
DOI: 10.57187/s.3588 -
Scientific Reports Jun 2024Acute kidney injury (AKI) is a systemic disease that affects energy metabolism in various remote organs in murine models of ischemic AKI. However, AKI-mediated effects...
Acute kidney injury (AKI) is a systemic disease that affects energy metabolism in various remote organs in murine models of ischemic AKI. However, AKI-mediated effects in the liver have not been comprehensively assessed. After inducing ischemic AKI in 8-10-week-old, male C57BL/6 mice, mass spectrometry metabolomics revealed that the liver had the most distinct phenotype 24 h after AKI versus 4 h and 7 days. Follow up studies with in vivo [C]-glucose tracing on liver and kidney 24 h after AKI revealed 4 major findings: (1) increased flux through glycolysis and the tricarboxylic (TCA) cycle in both kidney and liver; (2) depleted hepatic glutathione levels and its intermediates despite unchanged level of reactive oxygen species, suggesting glutathione consumption exceeds production due to systemic oxidative stress after AKI; (3) hepatic ATP depletion despite unchanged rate of mitochondrial respiration, suggesting increased ATP consumption relative to production; (4) increased hepatic and renal urea cycle intermediates suggesting hypercatabolism and upregulation of the urea cycle independent of impaired renal clearance of nitrogenous waste. Taken together, this is the first study to describe the hepatic metabolome after ischemic AKI in a murine model and demonstrates that there is significant liver-kidney crosstalk after AKI.
Topics: Animals; Acute Kidney Injury; Liver; Glutathione; Energy Metabolism; Kidney; Male; Mice; Mice, Inbred C57BL; Ischemia; Metabolomics; Disease Models, Animal; Oxidative Stress; Glycolysis; Metabolome
PubMed: 38879688
DOI: 10.1038/s41598-024-64586-4 -
New Biotechnology Jun 2024Regulatory authorities in biopharmaceutical industry emphasize process design by process understanding but applicable tools that are easy to implement are still missing....
Regulatory authorities in biopharmaceutical industry emphasize process design by process understanding but applicable tools that are easy to implement are still missing. Soft sensors are a promising tool for the implementation of the Quality by Design (QbD) approach and Process Analytical Technology (PAT). In particular, the correlation between viable cell counting and oxygen consumption was investigated, but problems remained: Either the process had to be modified for excluding CO in pH control, or complex ka models had to be set up for specific processes. In this work, a non-invasive soft sensor for simplified on-line cell counting based on dynamic oxygen uptake rate was developed with no need of special equipment. The dynamic oxygen uptake rates were determined by automated and periodic interruptions of gas supply in DASGIP® bioreactor systems, realized by a programmed Visual Basic script in the DASware® control software. With off-line cell counting, the two parameters were correlated based on linear regression and led to a robust model with a correlation coefficient of 0.92. Avoidance of oxygen starvation was achieved by gas flow reactivation at a certain minimum dissolved oxygen concentration. The soft sensor model was established in the exponential growth phase of a Chinese Hamster Ovary fed-batch process. Control studies showed no impact on cell growth by the discontinuous gas supply. This soft sensor is the first to be presented that does not require any specialized additional equipment as the methodology relies solely on the direct measurement of oxygen consumed by the cells in the bioreactor.
PubMed: 38878999
DOI: 10.1016/j.nbt.2024.06.001