ORCID Profile
0000-0002-0254-762X
Current Organisation
University of Birmingham
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Publisher: IMR Press
Date: 2008
DOI: 10.2741/2765
Abstract: The cumulative stressors of exercise manifest themselves at a cellular level by threatening the protein homeostasis of the cell. In these conditions, Heat Shock Proteins (HSP) are synthesised to chaperone mis-folded and denatured proteins. As such, the intracellular HSP response is thought to aid cell survival in the face of otherwise lethal cellular stress. Recently, the inducible isoform of the 70 Kda heat shock protein family, Hsp72 has been detected in the extracellular environment. Furthermore, the release of this protein into the circulation has been shown to occur in response to a range of exercise bouts. The present review summarises the current research on the exercise Hsp72 response, the possible mediators and mechanisms of extracellular (e)Hsp72 release, and the possible biological significance of this systemic response. In particular, the possible role of eHsp72 in the modulation of immunity during exercise is discussed.
Publisher: Georg Thieme Verlag KG
Date: 07-2004
Abstract: The purpose of the current research was to test the hypothesis that exercise induced leukocyte heat shock protein (HSP) expression is increased during periods of intensified exercise training. Seven male endurance cyclists carried out tests of maximal oxygen consumption and endurance capacity. These standard exercise tests were carried out prior to and following 6 days of prescribed intensified training. S led leukocytes were examined for Hsp27 and Hsp70 expression using a Fluorescence Activated Cell Scanner (EPICS XL, Coulter). During a period of overreaching, as signified by a drop in time to fatigue following the intensified training period (p = 0.02), the number of extracellular Hsp27 positive granulocytes increased in response to the VO(2)max test. Acute, intracellular HSP responses were observed in both baseline and overreached conditions. The present study showed that a period of intensified training caused adaptations in the acute heat shock protein exercise response, reflected by a greater increase of cell surface HSP positive leukocytes following heavy training.
Publisher: Wiley
Date: 29-11-2019
Abstract: Protein signaling between tissues, or tissue cross-talk is becoming recognized as a fundamental biological process that is incompletely understood. Shotgun proteomic analyses of tissues and plasma to explore this concept are regularly challenged by high dynamic range of protein abundance, which limits the identification of lower abundance proteins. In this viewpoint article, it is highlighted how a focus on proteins contained within extracellular vesicles (EVs) not only partially addresses this issue, but can also reveal an underappreciated complexity of the circulating proteome in various physiological and pathological contexts. Furthermore, how quantitative proteomics can inform EV mediated crosstalk is highlighted and the importance of high coverage, sensitive proteomic analyses of EVs to identify both the optimal methods to isolate EV subtypes of interest and proteins that characterize them is stressed.
Publisher: Springer Science and Business Media LLC
Date: 12-09-2016
DOI: 10.1038/NRD.2016.153
Abstract: Exercise reduces the risk of a multitude of disorders, from metabolic disease to cancer, but the molecular mechanisms mediating the protective effects of exercise are not completely understood. The realization that skeletal muscle is an endocrine organ capable of secreting proteins termed 'myokines', which participate in tissue crosstalk, provided a critical link in the exercise-health paradigm. However, the myokine field is still emerging, and several challenges remain in the discovery and validation of myokines. This Review considers these challenges and highlights some recently identified novel myokines with the potential to be therapeutically exploited in the treatment of metabolic disease and cancer.
Publisher: Wiley
Date: 11-03-2014
DOI: 10.1038/ICB.2014.16
Abstract: The lack of physical activity and overnutrition in our modern lifestyle culminates in what we now experience as the current obesity and diabetes pandemic. Medical research performed over the past 20 years identified chronic low-grade inflammation as a mediator of these metabolic disorders. Hence, finding therapeutic strategies against this underlying inflammation and identifying molecules implicated in this process is of significant importance. Following the observation of an increased plasma concentration of interleukin-6 (IL-6) in obese patients, this protein, known predominantly as a pro-inflammatory cytokine, came into focus. In an attempt to clarify its importance, several studies implicated IL-6 as a co-inducer of the development of obesity-associated insulin resistance, which precedes the development of type 2 diabetes. However, the identification of IL-6 as a myokine, a protein produced and secreted by skeletal muscle to fulfil paracrine or endocrine roles in the insulin-sensitizing effects following exercise, provides a contrasting and hence paradoxical identity of this protein in the context of metabolism. We review here the literature considering the complex, pleiotropic role of IL-6 in the context of metabolism in health and disease.
Publisher: Wiley
Date: 23-07-2020
DOI: 10.1111/SMS.13759
Abstract: The systemic response to exercise is dose‐dependent and involves a complex gene expression regulation and cross‐talk between tissues. This context ARISES the need for analyzing the influence of exercise dose on the profile of circulating microRNAs (c‐miRNAs), as emerging posttranscriptional regulators and intercellular communicators. Thus, we hypothesized that different exercise doses will determine specific c‐miRNA signatures that will highlight its potential as exercise dose biomarker. Nine active middle‐aged males completed a 10‐km race (10K), a half‐marathon (HM), and a marathon (M). Blood s les were collected immediately before and after races. Plasma RNA was extracted, and a global screening of 752 microRNAs was analyzed using RT‐qPCR. Three different c‐miRNA profiles were defined according to the three doses. In 10K, 14 c‐miRNAs were found to be differentially expressed between pre‐ and post‐exercise, 13 upregulated and 1 downregulated. Regarding HM, 13 c‐miRNAs were found to be differentially modulated, in all the cases upregulated. A total of 28 c‐miRNAs were found to be differentially expressed in M, 21 overexpressed and 7 repressed after this race. We had also found 3 common c‐miRNAs between 10K and M and 2 common c‐miRNAs between 10K and HM. In silico analysis supported a close association between exercise dose c‐miRNA profiles and cellular pathways linked to energy metabolism and cell cycle. In conclusion, we have observed that different exercise doses induced specific c‐miRNA profiles. So, our results point to c‐miRNAs as emerging exercise dose biomarkers and as one of regulatory mechanisms modulating the response to endurance exercise.
Publisher: American Physiological Society
Date: 07-2019
DOI: 10.1152/AJPENDO.00433.2018
Abstract: The health-promoting effects of physical activity to prevent and treat metabolic disorders are numerous. However, the underlying molecular mechanisms are not yet completely deciphered. In recent years, studies have referred to the liver as an endocrine organ, since it releases specific proteins called hepatokines. Some of these hepatokines are involved in whole body metabolic homeostasis and are theorized to participate in the development of metabolic disease. In this regard, the present review describes the role of Fibroblast Growth Factor 21, Fetuin-A, Angiopoietin-like protein 4, and Follistatin in metabolic disease and their production in response to acute exercise. Also, we discuss the potential role of hepatokines in mediating the beneficial effects of regular exercise and the future challenges to the discovery of new exercise-induced hepatokines.
Publisher: Wiley
Date: 29-04-2023
DOI: 10.1113/JP282468
Abstract: Extracellular vesicles (EVs) can be released from most cells in the body and act as intercellular messengers transferring information in their cargo to affect cellular function. A growing body of evidence suggests that a subset of EVs, referred to here as ‘small extracellular vesicles’ (sEVs), can accelerate or slow the processes of ageing and age‐related diseases dependent on their molecular cargo and cellular origin. Continued exploration of the vast complexity of the sEV cargo aims to further characterise these systemic vehicles that may be targeted to ameliorate age‐related pathologies. Marked progress in the development of mass spectrometry‐based technologies means that it is now possible to characterise a significant proportion of the proteome of sEVs (surface and cargo) via unbiased proteomics. This information is vital for identifying biomarkers and the development of sEV‐based therapeutics in the context of ageing. Although exercise and physical activity are prominent features in maintaining health in advancing years, the mechanisms responsible are unclear. A potential mechanism by which plasma sEVs released during exercise could influence ageing and senescence is via the increased delivery of cargo proteins that function as antioxidant enzymes or inhibitors of senescence. These have been observed to increase in sEVs following acute and chronic exercise, as identified via independent interrogation of high coverage, publicly available proteomic datasets. Establishing tropism and exchange of functionally active proteins by these processes represents a promising line of enquiry in implicating sEVs as biologically relevant mediators of the ageing process. image
Publisher: Elsevier BV
Date: 2012
DOI: 10.1016/J.CMET.2011.12.004
Abstract: The role of the cytokine interleukin-6 (IL-6) in metabolic homeostasis is the subject of conjecture. Recent work in Nature Medicine (Ellingsgaard et al., 2011) demonstrates that IL-6 released from skeletal muscle during exercise mediates crosstalk between insulin-sensitive tissues, intestinal L cells, and pancreatic islets to adapt to changes in insulin demand.
Publisher: Informa UK Limited
Date: 10-2007
DOI: 10.1080/02640410601113676
Abstract: The aim of the present study was to determine the effect of a carbohydrate mouthwash on running time-trial performance. On two separate occasions, seven recreationally active males (VO2max 57.8 ml x kg(-1) x min(-1), s = 3.7) completed a preloaded (15 min at 65%VO2max) time-trial of 45 min in duration on a motorized treadmill. At 6-min intervals during the preload and time-trial, participants were given either a 6% maltodextrin, 3% lemon juice solution (carbohydrate trial) or a 3% lemon juice placebo mouthwash (placebo trial) in a double-blind, randomized crossover design. Heart rate, oxygen consumption (VO2), respiratory exchange ratio (RER), and ratings of perceived exertion (RPE) were measured during the preload, and blood glucose and lactate were measured before and after the preload and time-trial. There were no significant differences in distance covered between trials (carbohydrate: 9333 m, s = 988 placebo: 9309 m, s = 993). Furthermore, there were no significant between-trial differences in heart rate and running speed during the time-trial, or VO2, RER or RPE during the preload. Blood lactate and glucose increased as a result of the exercise protocol, with no between-trial differences. In conclusion, there was no positive effect of a carbohydrate mouthwash on running performance of approximately 1 h duration.
Publisher: Wiley
Date: 16-03-2023
DOI: 10.1113/JP284047
Abstract: Small extracellular vesicles (sEVs) are released from all cell types and participate in the intercellular exchange of proteins, lipids, metabolites and nucleic acids. Proteomic, flow cytometry and nanoparticle tracking analyses suggest sEVs are released into circulation with exercise. However, interpretation of these data may be influenced by sources of bias introduced by different analytical approaches. Seven healthy participants carried out a high intensity intermittent training (HIIT) cycle protocol consisting of 4 × 30 s at a work‐rate corresponding to 200% of in idual max power (watts) interspersed by 4.5 min of active recovery. EDTA‐treated blood was collected before and immediately after the final effort. Platelet‐poor (PPP) and platelet‐free (PFP) plasma was derived by one or two centrifugal spins at 2500 g , respectively (15 min, room temperature). Platelets were counted on an automated haemocytometer. Plasma s les were assessed with the Exoview R100 platform, which immobilises sEVs expressing common tetraspanin markers CD9, CD63, CD81 and CD41a on microfluidic chips and with the aid of fluorescence imaging, counts their abundance at a single sEV resolution, importantly, without a pre‐isolation step. There was a lower number of platelets in the PFP than PPP, which was associated with a lower number of CD9, CD63 and CD41a positive sEVs. HIIT induced an increase in fluorescence counts in CD9, CD63 and CD81 positive sEVs in both PPP and PFP. These data support the concept that sEVs are released into circulation with exercise. Furthermore, platelet‐free plasma is the preferred, representative analyte to study sEV dynamics and phenotype during exercise. image Small extracellular vesicles (sEV) are nano‐sized particles containing protein, metabolites, lipid and RNA that can be transferred from cell to cell. Previous findings implicate that sEVs are released into circulation with exhaustive, aerobic exercise, but since there is no gold standard method to isolate sEVs, these findings may be subject to bias introduced by different approaches. Here, we use a novel method to immobilise and image sEVs, at single‐vesicle resolution, to show sEVs are released into circulation with high intensity intermittent exercise. Since platelet depletion of plasma results in a reduction in sEVs, platelet‐free plasma is the preferred analyte to examine sEV dynamics and phenotype in the context of exercise.
Publisher: Wiley
Date: 09-2013
DOI: 10.1111/DOM.12170
Abstract: Obesity and type 2 diabetes are now the most prevalent metabolic diseases in the Western world and the development of new strategies to treat these metabolic diseases is most warranted. Obesity results in a state of chronic low-grade inflammation in metabolically active tissues such as the liver, adipose tissue, brain and skeletal muscle. Work in our laboratory has focussed on the role of the cytokine interleukin-6 (IL)-6 and other IL-6-like cytokines that signal through the gp130 receptor complex. We have focussed on the role of blocking IL-6 trans-signalling to prevent inflammation on the one hand, and activating membrane-bound signalling to promote insulin sensitivity on the other hand. Since the cloning of the IL-6 gene nearly 30 years ago, a pattern has emerged associating IL-6 with a number of diseases associated with inflammation including rheumatoid arthritis (RA), Crohn's disease and several cancers. Accordingly, tocilizumab, an IL-6 receptor-inhibiting monoclonal antibody, is now useful for the treatment of RA. However, this may not be the most optimal strategy to block inflammation associated with IL-6 and may result in unwanted side effects that, paradoxically, could actually promote metabolic disease.
Publisher: Wiley
Date: 05-03-2020
Publisher: American Physiological Society
Date: 10-2007
DOI: 10.1152/JAPPLPHYSIOL.00484.2007
Abstract: The contribution of heat and exercise related stress to the release of heat shock protein 72 (HSP72) is currently unknown. The purpose of the present study was to determine the combined and independent effects of heat and exercise on the extracellular (e)HSP72 response. Eleven moderately trained male volunteers [means ± SD: age 21 ± 4 yr body mass 75.7 ± 7.7 kg maximal oxygen uptake (V̇o 2 max ) 57.8 ± 3.3 ml·kg −1 ·min −1 ] completed four 2-h, heat-manipulated, water-immersion trials. Trials were exercise-induced heat (EIH rectal temperature change +2.2°C), cl ed exercise (CEx 0°C), passive heating (PHT +2.3°C), and control (Con 0°C). Exercise trials (EIH and CEx) comprised deep-water running at 58.5 ± 2.4 and 59.1 ± 1.7% v̇o 2 max. eHSP72 and catecholamine concentrations were determined by ELISA and HPLC, respectively, pre- and postimmersion. All trials induced an eHSP72 response ( P 0.05) with postimmersion values significantly greater on EIH compared with other trials (6.0 ± 3.4 CEx 3.8 ± 2.6 PHT 2.7 ± 2.1 Con 2.2 ± 1.9 ng/ml). Exercising with a thermal cl blunted the eHSP72 response, but postimmersion values were also greater than Con. PHT induced a large catecholamine response, but postimmersion eHSP72 values did not reach significance vs. Con. Given that exercising with a thermal cl evoked a significant increase in plasma eHSP72 concentration, exercise-related stressors other than heat appeared influential in stimulating HSP72 release. Moreover, the catecholamine data from PHT suggest neither epinephrine nor norepinephrine was solely responsible for eHSP72 release.
Publisher: American Physiological Society
Date: 2008
DOI: 10.1152/JAPPLPHYSIOL.00792.2007
Abstract: The purpose of this study was to investigate the effects of prolonged exercise with and without a thermal cl on neutrophil trafficking, bacterial-stimulated neutrophil degranulation, stress hormones, and cytokine responses. Thirteen healthy male volunteers (means ± SE: age 21 ± 1 yr mass 74.9 ± 2.1 kg maximal oxygen uptake 58 ± 1 ml·kg −1 ·min −1 ) completed four randomly assigned, 2-h water-immersion trials separated by 7 days. Trials were exercise-induced heating (EX-H: water temperature 36°C), exercise with a thermal cl (EX-C: 24°C), passive heating (PA-H: 38.5°C), and control (CON: 35°C). EX-H and EX-C was comprised of 2 h of deep water running at 58% maximal oxygen uptake. Blood s les were collected at pre-, post-, and 1 h postimmersion. Core body temperature was unaltered on CON, cl ed on EX-C (−0.02°C), and rose by 2.23°C and 2.31°C on EX-H and PA-H, respectively. Exercising with a thermal cl did not blunt the neutrophilia postexercise (EX-C postexercise: 9.6 ± 1.1 and EX-H postexercise: 9.8 ± 1.0 × 10 9 /liter). Neutrophil degranulation decreased ( P 0.01) similarly immediately after PA-H (−21%), EX-C, and EX-H (−28%). EX-C blunted the circulating norepinephrine, cortisol, granulocyte-colony stimulating factor, and IL-6 response ( P 0.01) but not the plasma epinephrine and serum growth hormone response. These results show a similar neutrophilia and decrease in neutrophil degranulation after prolonged exercise with and without a thermal cl . As such, the rise in core body temperature does not appear to mediate neutrophil trafficking and degranulation responses to prolonged exercise. In addition, these results suggest a limited role for cortisol, granulocyte-colony stimulating factor, and IL-6 in the observed neutrophil responses to prolonged exercise.
Publisher: Springer Science and Business Media LLC
Date: 05-12-2010
Publisher: Elsevier BV
Date: 11-2014
Publisher: Elsevier BV
Date: 2018
DOI: 10.1016/J.CMET.2017.12.001
Abstract: Exercise stimulates the release of molecules into the circulation, supporting the concept that inter-tissue signaling proteins are important mediators of adaptations to exercise. Recognizing that many circulating proteins are packaged in extracellular vesicles (EVs), we employed quantitative proteomic techniques to characterize the exercise-induced secretion of EV-contained proteins. Following a 1-hr bout of cycling exercise in healthy humans, we observed an increase in the circulation of over 300 proteins, with a notable enrichment of several classes of proteins that compose exosomes and small vesicles. Pulse-chase and intravital imaging experiments suggested EVs liberated by exercise have a propensity to localize in the liver and can transfer their protein cargo. Moreover, by employing arteriovenous balance studies across the contracting human limb, we identified several novel candidate myokines, released into circulation independently of classical secretion. These data identify a new paradigm by which tissue crosstalk during exercise can exert systemic biological effects.
Publisher: American Physiological Society
Date: 10-2006
DOI: 10.1152/JAPPLPHYSIOL.00409.2006
Abstract: The stimulus for the release of 72-kDa heat shock protein (HSP72) during exercise in humans is currently unclear. Recent evidence in an animal model is suggestive of an involvement of catecholamines. The present study, therefore, investigated the effect of caffeine supplementation, a known stimulator of sympathetic activity, on the extracellular (e)HSP72 response to prolonged exercise. Ten healthy male endurance-trained cyclists were recruited (age: 21 ± 1 yr, maximum O 2 uptake 61.1 ± 1.7 ml·kg −1 ·min −1 , mean ± SE). Each subject was randomly assigned to ingest either 6 mg/kg body mass of caffeine (Caff) or placebo (Pla) 60 min before one of two 90-min bouts of cycling at 74 ± 1% maximum O 2 uptake. Trials were performed at least 7 days apart in a counterbalanced design. Venous blood s les were collected by venepuncture at pretreatment, preexercise, postexercise, and 1 h postexercise. Serum caffeine and plasma catecholamines were determined using a spectrophotometric assay and high-performance liquid chromatography, respectively. Plasma HSP72 and cortisol were determined by ELISA. Serum caffeine concentrations were significantly increased throughout Caff, while no increases were detected in Pla. Caffeine supplementation and exercise was associated with a greater eHSP72 response than exercise alone (postexercise Caff 8.6 ± 1.3 ng/ml Pla 5.9 ± 0.9 ng/ml). This greater eHSP72 response was associated with a greater epinephrine response to exercise in Caff. There was a significant increase in norepinephrine and cortisol, with no intertrial differences. The present data suggest that, in humans, catecholamines may be an important mediator of the exercise-induced increase in eHSP72 concentration.
Publisher: American Physiological Society
Date: 05-2018
DOI: 10.1152/PHYSIOLGENOMICS.00127.2017
Abstract: Exercise stimulates a wide array of biological processes, but the mechanisms involved are incompletely understood. Many previous studies have adopted transcriptomic analyses of skeletal muscle to address particular research questions, a process that ultimately results in the collection of large amounts of publicly available data that has not been fully integrated or interrogated. To maximize the use of these available transcriptomic exercise data sets, we have downloaded and reanalyzed them and formulated the data into a searchable online tool, geneXX. GeneXX is highly intuitive and free and provides immediate information regarding the response of a transcript of interest to exercise in skeletal muscle. To demonstrate its utility, we carried out a meta-analysis on the included data sets and show transcript changes in skeletal muscle that persist regardless of sex, exercise mode, and duration, some of which have had minimal attention in the context of exercise. We also demonstrate how geneXX can be used to formulate novel hypotheses on the complex effects of exercise, using preliminary data already generated. This resource represents a valuable tool for researchers with interests in human skeletal muscle adaptation to exercise.
Publisher: MDPI AG
Date: 28-09-2020
DOI: 10.3390/CELLS9102182
Abstract: Physical activity has systemic effects on the body, affecting almost every organ. It is important not only for general health and wellbeing, but also in the prevention of diseases. The mechanisms behind the therapeutic effects of physical activity are not completely understood however, studies indicate these benefits are not confined to simply managing energy balance and body weight. They also include systemic factors which are released into the circulation during exercise and which appear to underlie the myriad of benefits exercise can elicit. It was shown that along with a number of classical cytokines, active tissues also engage in inter-tissue communication via extracellular vesicles (EVs), specifically exosomes and other small EVs, which are able to deliver biomolecules to cells and alter their metabolism. Thus, EVs may play a role in the acute and systemic adaptations that take place during and after physical activity, and may be therapeutically useful in the treatment of a range of diseases, including metabolic disorders such as type 2 diabetes and obesity and the focus of this review, neurological disorders such as Alzheimer’s disease.
Publisher: American Physiological Society
Date: 10-2019
DOI: 10.1152/AJPENDO.00206.2019
Abstract: It has been suggested that interleukin-6 (IL-6) produced by adipocytes in obesity leads to liver insulin resistance, although this hypothesis has never been definitively tested. Accordingly, we did so by generating adipocyte-specific IL-6-deficient (AdipoIL-6 −/− ) mice and studying them in the context of diet-induced and genetic obesity. Mice carrying two floxed alleles of IL-6 (C57Bl/6J) were crossed with Cre recombinase-overexpressing mice driven by the adiponectin promoter to generate AdipoIL-6 −/− mice. AdipoIL-6 −/− and floxed littermate controls were fed a standard chow or high-fat diet (HFD) for 16 wk and comprehensively metabolically phenotyped. In addition to a diet-induced obesity model, we also examined the role of adipocyte-derived IL-6 in a genetic model of obesity and insulin resistance by crossing the AdipoIL-6 −/− mice with leptin-deficient ( ob/ob) mice. As expected, mice on HFD and ob/ob mice displayed marked weight gain and increased fat mass compared with chow-fed and ob/+ (littermate control) animals, respectively. However, deletion of IL-6 from adipocytes in either model had no effect on glucose tolerance or fasting hyperinsulinemia. We concluded that adipocyte-specific IL-6 does not contribute to whole body glucose intolerance in obese mice.
Publisher: Elsevier
Date: 2006
Publisher: Elsevier BV
Date: 12-2003
DOI: 10.1016/S0022-3999(03)00073-4
Abstract: Chronic stress has been associated with impaired response to influenza vaccination in the elderly. This study investigated whether mild, intermittent stress experienced by young, healthy adults has a similar effect. Antibody and psychological status were determined prevaccination and 5 weeks and 5 months later a fourfold increase in antibody to at least one viral strain was considered protective. At 5 months, unprotected participants reported significantly more life events and tended to report more perceived stress than those who were protected. Psychological stress is detrimental to long-term maintenance of antibody levels following vaccination in young, healthy adults.
Publisher: Springer Science and Business Media LLC
Date: 07-10-2008
Publisher: Springer Science and Business Media LLC
Date: 2006
DOI: 10.2165/00007256-200636110-00003
Abstract: Athletes, military personnel, fire fighters, mountaineers and astronauts may be required to perform in environmental extremes (e.g. heat, cold, high altitude and microgravity). Exercising in hot versus thermoneutral conditions (where core temperature is > or = 1 degrees C higher in hot conditions) augments circulating stress hormones, catecholamines and cytokines with associated increases in circulating leukocytes. Studies that have cl ed the rise in core temperature during exercise (by exercising in cool water) demonstrate a large contribution of the rise in core temperature in the leukocytosis and cytokinaemia of exercise. However, with the exception of lowered stimulated lymphocyte responses after exercise in the heat, and in exertional heat illness patients (core temperature > 40 degrees C), recent laboratory studies show a limited effect of exercise in the heat on neutrophil function, monocyte function, natural killer cell activity and mucosal immunity. Therefore, most of the available evidence does not support the contention that exercising in the heat poses a greater threat to immune function (vs thermoneutral conditions). From a critical standpoint, due to ethical committee restrictions, most laboratory studies have evoked modest core temperature responses ( 40.6 degrees C) and identify the effects of acclimatisation on neuroendocrine and immune responses to exercise-heat stress. Laboratory studies can provide useful information by, for ex le, applying the thermal cl model to examine the involvement of the rise in core temperature in the functional immune modifications associated with prolonged exercise. Studies investigating the effects of cold, high altitude and microgravity on immunity and infection incidence are often hindered by extraneous stressors (e.g. isolation). Nevertheless, the available evidence does not support the popular belief that short- or long-term cold exposure, with or without exercise, suppresses immunity and increases infection incidence. In fact, controlled laboratory studies indicate immuno-stimulatory effects of cold exposure. Although some evidence shows that ascent to high altitude increases infection incidence, clear conclusions are difficult to make because of some overlap with the symptoms of acute mountain sickness. Studies have reported suppressed cell-mediated immunity in mountaineers at high altitude and in astronauts after re-entering the normal gravity environment however, the impact of this finding on resistance to infection remains unclear.
Publisher: Springer Science and Business Media LLC
Date: 2006
DOI: 10.1379/CSC-212.1
Abstract: Heat shock protein 72 (Hsp72) has been detected in the peripheral circulation of humans. Because intracellular Hsp72 binds to aggregated proteins, we hypothesized that postexercise plasma-derived Hsp72 concentrations would be greater than serum-derived Hsp72 because of binding of Hsp72 to aggregated clotting proteins in serum. Postexercise serum, heparin, and ethylenediaminetetraacetic acid (EDTA) s les were collected from 9 recreationally active males and were analyzed for Hsp72 by enzyme-linked immunosorbent assay. In line with our hypothesis, EDTA-treated blood was significantly higher in Hsp72 concentration than all other treatments (P < or = 0.001), whilst heparin plasma (LH) was significantly higher than serum derived on ice (SI) and at room temperature (SR) (P < 0.05 EDTA: 6.46 +/- 0.76, LH: 2.73 +/- 2.26, SI: 0.13 +/- 0.24, SR: 0.20 +/- 0.32 ng/mL). Because previous research has tended to report serum data at the lowest point of the detectable range of the assay, it is recommended that EDTA specimen tubes be used in future investigations.
Publisher: Wiley
Date: 11-10-2013
Publisher: Informa UK Limited
Date: 12-2003
DOI: 10.1080/0264041031000140464
Abstract: The significance of in vitro changes in immune function accompanying exercise training is unclear. To determine the effect of exercise on the response of the intact immune system to a challenge in vivo, we measured the speed and overall immunoglobulin G (IgG) response to influenza vaccination in humans engaged in different intensities of activity. Male participants (n = 21) were split into heavy and light training groups. Venous blood s les were collected 0, 2, 4, 7, 10 and 14 days after vaccination with trivalent influenza vaccine, and also 12 months after initial vaccination. Serum IgG was determined by enzyme-linked immunosorbant assay. There was a significant difference in baseline IgG between groups, but no difference in IgG concentration 14 days after vaccination. The IgG concentration remained elevated 12 months post-vaccination in the heavy training group. The results suggest a positive relationship between habitual physical activity and baseline antibody concentrations, which, in turn, affects the relative magnitude (fold or percentage increase) of the antibody response to vaccination. The training loads of the participants in this study had no effect on overall IgG measured 14 days after vaccination.
Publisher: Elsevier BV
Date: 03-2012
Publisher: The Endocrine Society
Date: 2011
DOI: 10.1210/EN.2010-0868
Abstract: Follistatin is a member of the TGF-β super family and inhibits the action of myostatin to regulate skeletal muscle growth. The regulation of follistatin during physical exercise is unclear but may be important because physical activity is a major intervention to prevent age-related sarcopenia. First, healthy subjects performed either bicycle or one-legged knee extensor exercise. Arterial-venous differences were assessed during the one-legged knee extensor experiment. Next, mice performed 1 h of swimming, and the expression of follistatin was examined in various tissues using quantitative PCR. Western blotting assessed follistatin protein content in the liver. IL-6 and epinephrine were investigated as drivers of follistatin secretion. After 3 h of bicycle exercise, plasma follistatin increased 3 h into recovery with a peak of 7-fold. No net release of follistatin could be detected from the exercising limb. In mice performing a bout of swimming exercise, increases in plasma follistatin as well as follistatin mRNA and protein expression in the liver were observed. IL-6 infusion to healthy young men did not affect the follistatin concentration in the circulation. When mice were stimulated with epinephrine, no increase in the hepatic mRNA of follistatin was observed. This is the first study to demonstrate that plasma follistatin is increased during exercise and most likely originates from the liver. These data introduce new perspectives regarding muscle-liver cross talk during exercise and during recovery from exercise.
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Martin Whitham.