Skeletal Muscle Gene Expression Signatures of Obese High and Low Responders to Endurance Exercise Training.

CONTEXT: Exercise training is known to improve glucose tolerance and reverse insulin resistance in people with obesity. However, some individuals fail to improve or even decline in their clinical traits following exercise intervention. OBJECTIVE: This study focused on gene expression and DNA methylation signatures in skeletal muscle of low (LRE) and high responders (RES) to 8 weeks of supervised endurance training. METHODS: We performed skeletal muscle gene expression and DNA methylation analyses in LRE and RES before and after exercise intervention. Additionally, we applied the least absolute shrinkage and selection operator (LASSO) approach to identify predictive marker genes of exercise outcome. RESULTS: We show that the two groups differ markedly already before the intervention. RES were characterized by lower expression of genes involved in DNA replication and repair, and higher expression of extracellular matrix (ECM) components. The LASSO approach identified several novel candidates (eg, ZCWPW2, FOXRED1, STK40) that have not been previously described in the context of obesity and exercise response. Following the intervention, LRE reacted with expression changes of genes related to inflammation and apoptosis, RES with genes related to mitochondrial function. LRE exhibited significantly higher expression of ECM components compared to RES, suggesting improper remodeling and potential negative effects on insulin sensitivity. Between 45% and 70% of differences in gene expression could be linked to differences in DNA methylation. CONCLUSION: Together, our data offer an insight into molecular mechanisms underlying differences in response to exercise and provide potential novel markers for the success of intervention.

Acute and long-term exercise adaptation of adipose tissue and skeletal muscle in humans: a matched transcriptomics approach after 8-week training-intervention.

BACKGROUND: Exercise exerts many health benefits by directly inducing molecular alterations in physically utilized skeletal muscle. Molecular adaptations of subcutaneous adipose tissue (SCAT) might also contribute to the prevention of metabolic diseases. AIM: To characterize the response of human SCAT based on changes in transcripts and mitochondrial respiration to acute and repeated bouts of exercise in comparison to skeletal muscle. METHODS: Sedentary participants (27 ± 4 yrs) with overweight or obesity underwent 8-week supervised endurance exercise 3×1h/week at 80% VO2peak. Before, 60 min after the first and last exercise bout and 5 days post intervention, biopsies were taken for transcriptomic analyses and high-resolution respirometry (n = 14, 8 female/6 male). RESULTS: In SCAT, we found 37 acutely regulated transcripts (FC > 1.2, FDR < 10%) after the first exercise bout compared to 394, respectively, in skeletal muscle. Regulation of only 5 transcripts overlapped between tissues highlighting their differential response. Upstream and enrichment analyses revealed reduced transcripts of lipid uptake, storage and lipogenesis directly after exercise in SCAT and point to ß-adrenergic regulation as potential major driver. The data also suggest an exercise-induced modulation of the circadian clock in SCAT. Neither term was associated with transcriptomic changes in skeletal muscle. No evidence for beigeing/browning was found in SCAT along with unchanged respiration. CONCLUSIONS: Adipose tissue responds completely distinct from adaptations of skeletal muscle to exercise. The acute and repeated reduction in transcripts of lipid storage and lipogenesis, interconnected with a modulated circadian rhythm, can counteract metabolic syndrome progression toward diabetes.

The Acute Cytokine Response to 30-Minute Exercise Bouts Before and After 8-Week Endurance Training in Individuals With Obesity.

CONTEXT: One acute bout of exercise leads to a rapid increase in the systemic cytokine concentration. Regular exercise might alter the cytokine response, in particular in beforehand untrained and obese individuals. OBJECTIVE: Using a proximity extension assay, we studied the effects of acute exercise as well as endurance training on a panel of 92 cytokines related to inflammation. METHODS: A total of 22 individuals (30 ± 9 years; peak oxygen uptake [VO2peak] 25.2 ± 4.2 mL/[kg × min]; body mass index [BMI] 31.7 ± 4.4) participated in an 8-week endurance exercise intervention. Blood samples were collected before and immediately after 30 minutes' ergometer exercise at 80% VO2peak. RESULTS: Before and after the training intervention, 40 and 37 cytokines, respectively, were acutely increased more than 1.2-fold (Benjamini-Hochberg [BH]-adjusted P < .05). The exercise intervention did not change the acute increase in cytokines nor the resting cytokine levels, whereas fitness was improved and adiposity reduced. The increase in fitness led to a slight increase in power output when exercising at the same heart rate, which might explain the comparable increase in cytokines before and after the intervention. The largest acute increase was found for OSM, TGFA, CXCL1 and 5, and TNFSF14 (≥ 1.9-fold, BH-adjusted P < .001). The transcript levels of these proteins in whole blood were also elevated, particularly in the trained state. Only the acute increase in IL6 (1.3-fold) was related to the increase in lactate, confirming the lactate-driven secretion of IL6. CONCLUSION: Our comprehensive proteomics approach detected several underexplored serum exerkines with up to now less understood function in the adaptation to exercise.

Label-Free Determination of the Kinetic Parameters of Protein-Aptamer Interaction by Surface Plasmon Resonance.

Due to their high specificity and affinity to target molecules, aptamers can be used as powerful tools in diagnostics, therapeutics, and environmental or food analytics. For the use in various applications, the detailed characterization of their binding behavior is an important step after selection to determine the interaction strength between the aptamer and its target and to find the best kinetics depending on the field of application. The surface plasmon resonance (SPR) spectroscopy is a powerful technology to investigate important parameters in molecular interaction, for example, kinetics, affinity, and specificity. The most-used system is the Biacore™ SPR system which comprises an optical biosensor for label-free monitoring of binding events in real time based on SPR. This biophysical phenomenon describes the changes in refractive index on a sensor surface which can be used to measure binding events and to determine kinetic constants. In this chapter, a detailed protocol for the determination of kinetic constants for protein-aptamer interaction is provided. An 82-nt long ssDNA aptamer which are targeted against human urokinase is used as a model system for determination of binding and dissociation constants using Biacore™ SPR technology. A detailed note section provides useful tips and pitfalls at the end of this chapter.

Exercise restores brain insulin sensitivity in sedentary adults who are overweight and obese.

BACKGROUNDInsulin resistance of the brain can unfavorably affect long-term weight maintenance and body fat distribution. Little is known if and how brain insulin sensitivity can be restored in humans. We aimed to evaluate the effects of an exercise intervention on insulin sensitivity of the brain and how this relates to exercise-induced changes in whole-body metabolism and behavior.METHODSIn this clinical trial, sedentary participants who were overweight and obese underwent an 8-week supervised aerobic training intervention. Brain insulin sensitivity was assessed in 21 participants (14 women, 7 men; age range 21-59 years; BMI range 27.5-45.5 kg/m2) using functional MRI, combined with intranasal administration of insulin, before and after the intervention.RESULTSThe exercise program resulted in enhanced brain insulin action to the level of a person of healthy weight, demonstrated by increased insulin-induced striatal activity and strengthened hippocampal functional connectivity. Improved brain insulin action correlated with increased mitochondrial respiration in skeletal muscle, reductions in visceral fat and hunger, as well as improved cognition. Mediation analyses suggest that improved brain insulin responsiveness helps mediate the peripheral exercise effects leading to healthier body fat distribution and reduced perception of hunger.CONCLUSIONOur study demonstrates that an 8-week exercise intervention in sedentary individuals can restore insulin action in the brain. Hence, the ameliorating benefits of exercise toward brain insulin resistance may provide an objective therapeutic target in humans in the challenge to reduce diabetes risk factors.TRIAL REGISTRATIONClinicalTrials.gov (NCT03151590).FUNDINGBMBF/DZD 01GI0925.

The use of high-affinity polyhistidine binders as masking probes for the selection of an NDM-1 specific aptamer.

The emergence of carbapenemase-producing multi-drug resistant Enterobacteriaceae poses a dramatic, world-wide health risk. Limited treatment options and a lack of easy-to-use methods for the detection of infections with multi-drug resistant bacteria leave the health-care system with a fast-growing challenge. Aptamers are single stranded DNA or RNA molecules that bind to their targets with high affinity and specificity and can therefore serve as outstanding detection probes. However, an effective aptamer selection process is often hampered by non-specific binding. When selections are carried out against recombinant proteins, purification tags (e.g. polyhistidine) serve as attractive side targets, which may impede protein target binding. In this study, aptamer selection was carried out against N-terminally hexa-histidine tagged New Delhi metallo-ß-lactamase 1. After 14 selection rounds binding to polyhistidine was detected rather than to New Delhi metallo-ß-lactamase 1. Hence, the selection strategy was changed. As one aptamer candidate showed remarkable binding affinity to polyhistidine, it was used as a masking probe and selection was restarted from selection round 10. Finally, after three consecutive selection rounds, an aptamer with specific binding properties to New Delhi metallo-ß-lactamase 1 was identified. This aptamer may serve as a much-needed detection probe for New Delhi metallo-ß-lactamase 1 expressing Enterobacteriaceae.

Exercise-Induced N-Lactoylphenylalanine Predicts Adipose Tissue Loss during Endurance Training in Overweight and Obese Humans.

Physical exercise is a powerful measure to prevent cardiometabolic diseases. However, the individual response to lifestyle interventions is variable and cannot, to date, be predicted. N-Lactoylphenylalanine (Lac-Phe) produced during exercise has recently been shown to mediate weight loss in obese mice. Lac-Phe could also contribute to, and potentially explain differences in, the effectiveness of exercise interventions in humans. Sedentary overweight and obese subjects completed an 8-week supervised endurance exercise intervention (n = 22). Before and after the intervention, plasma levels of Lac-Phe were determined by UHPLC-MS in the resting state and immediately after an acute bout of endurance exercise. Adipose tissue volume was quantified using MRI. Acute exercise caused a pronounced increase in Lac-Phe, both before and after the intervention. Higher levels of Lac-Phe after acute exercise were associated with a greater reduction in abdominal subcutaneous and, to a lower degree, visceral adipose tissue during the intervention. Lac-Phe produced during physical activity could contribute to weight loss by acting as a signaling molecule that regulates food intake, as previously shown in mice. Quantification of Lac-Phe during an exercise test could be employed as a tool to predict and potentially improve the individual response to exercise-based lifestyle interventions in overweight humans and those with obesity.

TGF-ß Induction of miR-143/145 Is Associated to Exercise Response by Influencing Differentiation and Insulin Signaling Molecules in Human Skeletal Muscle.

Physical training improves insulin sensitivity and can prevent type 2 diabetes (T2D). However, approximately 20% of individuals lack a beneficial outcome in glycemic control. TGF-ß, identified as a possible upstream regulator involved in this low response, is also a potent regulator of microRNAs (miRNAs). The aim of this study was to elucidate the potential impact of TGF-ß-driven miRNAs on individual exercise response. Non-targeted long and sncRNA sequencing analyses of TGF-ß1-treated human skeletal muscle cells corroborated the effects of TGF-ß1 on muscle cell differentiation, the induction of extracellular matrix components, and identified several TGF-ß1-regulated miRNAs. qPCR validated a potent upregulation of miR-143-3p/145-5p and miR-181a2-5p by TGF-ß1 in both human myoblasts and differentiated myotubes. Healthy subjects who were overweight or obese participated in a supervised 8-week endurance training intervention (n = 40) and were categorized as responder or low responder in glycemic control based on fold change ISIMats (≥+1.1 or <+1.1, respectively). In skeletal muscle biopsies of low responders, TGF-ß signaling and miR-143/145 cluster levels were induced by training at much higher rates than among responders. Target-mining revealed HDACs, MYHs, and insulin signaling components INSR and IRS1 as potential miR-143/145 cluster targets. All these targets were down-regulated in TGF-ß1-treated myotubes. Transfection of miR-143-3p/145-5p mimics in differentiated myotubes validated MYH1, MYH4, and IRS1 as miR-143/145 cluster targets. Elevated TGF-ß signaling and miR-143/145 cluster induction in skeletal muscle of low responders might obstruct improvements in insulin sensitivity by training in two ways: by a negative impact of miR-143-3p on muscle cell fusion and myofiber functionality and by directly impairing insulin signaling via a reduction in INSR by TGF-ß and finetuned IRS1 suppression by miR-143-3p.

Pancreatic fat cells of humans with type 2 diabetes display reduced adipogenic and lipolytic activity.

Obesity, especially visceral fat accumulation, increases the risk of type 2 diabetes (T2D). The purpose of this study was to investigate the impact of T2D on the pancreatic fat depot. Pancreatic fat pads from 17 partial pancreatectomized patients (PPP) were collected, pancreatic preadipocytes isolated, and in vitro differentiated. Patients were grouped using HbA1c into normal glucose tolerant (NGT), prediabetic (PD), and T2D. Transcriptome profiles of preadipocytes and adipocytes were assessed by RNAseq. Insulin sensitivity was estimated by quantifying AKT phosphorylation on Western blots. Lipogenic capacity was assessed with oil red O staining, lipolytic activity via fatty acid release. Secreted factors were measured using ELISA. Comparative transcriptome analysis of preadipocytes and adipocytes indicates defective upregulation of genes governing adipogenesis (NR1H3), lipogenesis (FASN, SCD, ELOVL6, and FADS1), and lipolysis (LIPE) during differentiation of cells from T2D-PPP. In addition, the ratio of leptin/adiponectin mRNA was higher in T2D than in NGT-PPP. Preadipocytes and adipocytes of NGT-PPP were more insulin sensitive than T2D-PPP cells in regard to AKT phosphorylation. Triglyceride accumulation was similar in NGT and T2D adipocytes. Despite a high expression of the receptors NPR1 and NPR2 in NGT and T2D adipocytes, lipolysis was stimulated by ANP 1.74-fold in NGT cells only. This stimulation was further increased by the PDE5 inhibitor dipyridamole (3.09-fold). Dipyridamole and forskolin increased lipolysis receptor independently 1.88-fold and 1.48-fold, respectively, solely in NGT cells. In conclusion, the metabolic status persistently affects differentiation and lipolysis of pancreatic adipocytes. These alterations could aggravate the development of T2D.

Aryl Hydrocarbon Receptor Signaling Is Functional in Immune Cells of Rainbow Trout (Oncorhynchus mykiss).

The arylhydrocarbon receptor (AhR) is an important signaling pathway in the immune system of mammals. In addition to its physiological functions, the receptor mediates the immunotoxic actions of a diverse range of environmental contaminants that bind to and activate the AhR, including planar halogenated aromatic hydrocarbons (PHAHs or dioxin-like compounds) and polynuclear aromatic hydrocarbons (PAHs). AhR-binding xenobiotics are immunotoxic not only to mammals but to teleost fish as well. To date, however, it is unknown if the AhR pathway is active in the immune system of fish and thus may act as molecular initiating event in the immunotoxicity of AhR-binding xenobiotics to fish. The present study aims to examine the presence of functional AhR signaling in immune cells of rainbow trout (Oncorhynchus mykiss). Focus is given to the toxicologically relevant AhR2 clade. By means of RT-qPCR and in situ hybdridization, we show that immune cells of rainbow trout express ahr 2α and ahr 2ß mRNA; this applies for immune cells isolated from the head kidney and from the peripheral blood. Furthermore, we show that in vivo as well as in vitro exposure to the AhR ligand, benzo(a)pyrene (BaP), causes upregulation of the AhR-regulated gene, cytochrome p4501a, in rainbow trout immune cells, and that this induction is inhibited by co-treatment with an AhR antagonist. Taken together, these findings provide evidence that functional AhR signaling exists in the immune cells of the teleost species, rainbow trout.

Response of Mitochondrial Respiration in Adipose Tissue and Muscle to 8 Weeks of Endurance Exercise in Obese Subjects.

CONTEXT: Exercise training improves glycemic control and increases mitochondrial content and respiration capacity in skeletal muscle. Rodent studies suggest that training increases mitochondrial respiration in adipose tissue. OBJECTIVE: To assess the effects of endurance training on respiratory capacities of human skeletal muscle and abdominal subcutaneous adipose tissue and to study the correlation with improvement in insulin sensitivity. DESIGN: Using high-resolution respirometry, we analyzed biopsies from 25 sedentary (VO2 peak 25.1 ± 4.0 VO2 mL/[kg*min]) subjects (16 female, 9 male; 29.8 ± 8.4 years) with obesity (body mass index [BMI] 31.5 ± 4.3 kg/m2), who did not have diabetes. They performed a supervised endurance training over 8 weeks (3 × 1 hour/week at 80% VO2 peak). RESULTS: Based on change in insulin sensitivity after intervention (using the Matsuda insulin sensitivity index [ISIMats]), subjects were grouped in subgroups as responders (>15% increase in ISIMats) and low-responders. The response in ISIMats was correlated to a reduction of subcutaneous and visceral adipose tissue volume. Both groups exhibited similar increases in fitness, respiratory capacity, and abundance of mitochondrial enzymes in skeletal muscle fibers. Respiratory capacities in subcutaneous adipose tissue were not altered by the intervention. Compared with muscle fibers, adipose tissue respiration showed a preference for ß-oxidation and complex II substrates. Respiratory capacities were higher in adipose tissue from female participants. CONCLUSION: Our data show that the improvement of peripheral insulin sensitivity after endurance training is not directly related to an increase in mitochondrial respiratory capacities in skeletal muscle and occurs without an increase in the respiratory capacity of subcutaneous adipose tissue.

Uptake of silica nanoparticles in the brain and effects on neuronal differentiation using different in vitro models.

Nanomedicine offers a promising tool for therapies of brain diseases, but they may be associated with potential adverse effects. The aim of this study was to investigate the uptake of silica-nanoparticles engineered for laser-tissue soldering in the brain using SH-SY5Y cells, dissociated and organotypic slice cultures from rat hippocampus. Nanoparticles were predominantly taken up by microglial cells in the hippocampal cultures but nanoparticles were also found in differentiated SH-SY5Y cells. The uptake was time- and concentration-dependent in primary hippocampal cells. Transmission electron microscopy experiments demonstrated nanoparticle aggregates and single particles in the cytoplasm. Nanoparticles were found in the endoplasmic reticulum, but not in other cellular compartments. Nanoparticle exposure did not impair cell viability and neuroinflammation in primary hippocampal cultures at all times investigated. Neurite outgrowth was not significantly altered in SH-SY5Y cells, but the neuronal differentiation markers indicated a reduction in neuronal differentiation induction after nanoparticle exposure.

Evaluation of endocytosis of silica particles used in biodegradable implants in the brain.

Silica nanoparticles embedded in a biodegradable scaffold have been proposed to offer several advantages when used in laser-tissue-soldering of blood vessels in the brain. During degradation, these nanoparticles are likely to be released into the surrounding brain tissue. The aim of this study was to investigate possible cellular uptake mechanism(s) of the two silica nanoparticle types in microglial cells as well as their effect on autophagy and inflammatory cytokines. The nanoparticle uptake was analysed quantitatively using high-content analysis. Nanoparticle incubation did not modulate cytokine secretion and autophagy at any time point investigated. The nanoparticles were taken up by the microglia cells in a time- and particle-dependent manner. The maximal uptake was reached after 4hours and the nanoparticles were found in the endoplasmic reticulum and lysosomes. Macropinocytosis and phagocytosis were predominantly responsible for the uptake, whereas clathrin- and caveolin-independent endocytosis were involved to a minor extent.

The teleostean liver as an immunological organ: Intrahepatic immune cells (IHICs) in healthy and benzo[a]pyrene challenged rainbow trout (Oncorhynchus mykiss).

The existence of a resident population of intrahepatic immune cells (IHICs) is well documented for mammalian vertebrates, however, it is uncertain whether IHICs are present in the liver of teleostean fish. In the present study we investigated whether trout liver contains an IHIC population, and if so, what the relative cellular composition of this population is. The results provide clear evidence for the existence of an IHIC population in trout liver, which constitutes 15-29% of the non-hepatocytes in the liver, and with a cellular composition different to that of the blood leukocyte population. We also analyzed the response of IHICs to a non-infectious liver challenge with the hepatotoxic and immunotoxic chemical, benzo[a]pyrene (BaP). Juvenile trout were treated with BaP (25 or 100mg/kgbw) at levels sufficient to induce the molecular pathway of BaP metabolism while not causing pathological and inflammatory liver changes. The IHIC population responded to the BaP treatments in a way that differed from the responses of the leukocyte populations in trout blood and spleen, suggesting that IHICs are an independently regulated immune cell population.

An in vitro toxicity evaluation of gold-, PLLA- and PCL-coated silica nanoparticles in neuronal cells for nanoparticle-assisted laser-tissue soldering.

The uptake of silica (Si) and gold (Au) nanoparticles (NPs) engineered for laser-tissue soldering in the brain was investigated using microglial cells and undifferentiated and differentiated SH-SY5Y cells. It is not known what effects NPs elicit once entering the brain. Cellular uptake, cytotoxicity, apoptosis, and the potential induction of oxidative stress by means of depletion of glutathione levels were determined after NP exposure at concentrations of 10(3) and 10(9)NPs/ml. Au-, silica poly (ε-caprolactone) (Si-PCL-) and silica poly-L-lactide (Si-PLLA)-NPs were taken up by all cells investigated. Aggregates and single NPs were found in membrane-surrounded vacuoles and the cytoplasm, but not in the nucleus. Both NP concentrations investigated did not result in cytotoxicity or apoptosis, but reduced glutathione (GSH) levels predominantly at 6 and 24h, but not after 12 h of NP exposure in the microglial cells. NP exposure-induced GSH depletion was concentration-dependent in both cell lines. Si-PCL-NPs induced the strongest effect of GSH depletion followed by Si-PLLA-NPs and Au-NPs. NP size seems to be an important characteristic for this effect. Overall, Au-NPs are most promising for laser-assisted vascular soldering in the brain. Further studies are necessary to further evaluate possible effects of these NPs in neuronal cells.

Tissue-specific metabolism of benzo[a]pyrene in rainbow trout (Oncorhynchus mykiss): a comparison between the liver and immune organs.

Polycyclic aromatic hydrocarbons (PAHs) are immunotoxicants in fish. In mammals, phase I metabolites are believed to be critically involved in the immunotoxicity of PAHs. This mechanism has been suggested for fish as well. The present study investigates the capacity of immune organs (head kidney, spleen) of rainbow trout, Oncorhynchus mykiss, to metabolize the prototypic PAH, benzo[a]pyrene (BaP). To this end, we analyzed 1) the induction of enzymatic capacity measured as 7-ethoxyresorufin-O-deethylase (EROD) activity in immune organs compared with liver, 2) the organ profiles of BaP metabolites generated in vivo, and 3) rates of microsomal BaP metabolite production in vitro. All measurements were done for control fish and for fish treated with an intraperitoneal injection of 15 mg BaP/kg body weight. In exposed trout, the liver, head kidney, and spleen contained similar levels of BaP, whereas EROD induction differed significantly between the organs, with liver showing the highest induction factor (132.8×), followed by head kidney (38.4×) and spleen (1.4×). Likewise, rates of microsomal metabolite formation experienced the highest induction in the liver of BaP-exposed trout, followed by the head kidney and spleen. Microsomes from control fish displayed tissue-specific differences in metabolite production. In contrast, in BaP-exposed trout, microsomes of all organs produced the potentially immunotoxic BaP-7,8-dihydrodiol as the main metabolite. The findings from this study show that PAHs, like BaP, are distributed into immune organs of fish and provide the first evidence that immune organs possess inducible PAH metabolism leading to in situ production of potentially immunotoxic PAH metabolites.

Immunotoxic effects of environmental toxicants in fish - how to assess them?

Numerous environmental chemicals, both long-known toxicants such as persistent organic pollutants as well as emerging contaminants such as pharmaceuticals, are known to modulate immune parameters of wildlife species, what can have adverse consequences for the fitness of individuals including their capability to resist pathogen infections. Despite frequent field observations of impaired immunocompetence and increased disease incidence in contaminant-exposed wildlife populations, the potential relevance of immunotoxic effects for the ecological impact of chemicals is rarely considered in ecotoxicological risk assessment. A limiting factor in the assessment of immunotoxic effects might be the complexity of the immune system what makes it difficult (1) to select appropriate exposure and effect parameters out of the many immune parameters which could be measured, and (2) to evaluate the significance of the selected parameters for the overall fitness and immunocompetence of the organism. Here, we present - on the example of teleost fishes - a brief discussion of how to assess chemical impact on the immune system using parameters at different levels of complexity and integration: immune mediators, humoral immune effectors, cellular immune defenses, macroscopical and microscopical responses of lymphoid tissues and organs, and host resistance to pathogens. Importantly, adverse effects of chemicals on immunocompetence may be detectable only after immune system activation, e.g., after pathogen challenge, but not in the resting immune system of non-infected fish. Current limitations to further development and implementation of immunotoxicity assays and parameters in ecotoxicological risk assessment are not primarily due to technological constraints, but are related from insufficient knowledge of (1) possible modes of action in the immune system, (2) the importance of intra- and inter-species immune system variability for the response against chemical stressors, and (3) deficits in conceptual and mechanistic assessment of combination effects of chemicals and pathogens.

Elite female soccer players perform more high-intensity running when playing in international games compared with domestic league games.

The purpose of this study was to compare movement pattern, fatigue development, and heart rate (HR) for top-class elite female players when playing international (INT) vs. domestic league games (DOM). Video-based time-motion analyses and HR recordings were performed on 17 players during INT and DOM. The distances covered in high-intensity running (HIR) and sprinting were longer (p < 0.05) in INT compared with DOM. More (p < 0.05) HIR was covered in INT than DOM during first and second half. Additionally, more (p < 0.05) sprinting occurred in INT compared with DOM in the first half. In both game types, the amount of HIR was reduced by 24-27% (p < 0.05) in the last 15-minute period compared with the first four 15-minute periods of the game. The midfielders covered longer (p < 0.05) distances with HIR in INT than in DOM over the entire game and in the most intense 5-minute period of the games, whereas no differences were observed between the game types for defenders. No difference in the HR response was found between INT and DOM. In conclusion, more HIR and sprinting occur in international compared with domestic games, which may affect the fatigue development for players in physically demanding roles. Thus, our results are important to coaches to prepare players to meet the challenges of international soccer games and show that the ability to perform intense intermittent exercise should be trained regularly in elite female players.

Monitoring daunorubicin-induced alterations in protein expression in pancreas carcinoma cells by two-dimensional gel electrophoresis.

Tumors of the pancreas are characterized by a high intrinsic potency to develop chemoresistance towards cytotoxic drugs, which is the main cause of ineffective treatment. The phenomenon of multidrug resistance is known to be a multifactorial event in which several mechanisms act simultaneously. We investigated the response of pancreas tumor cells after exposure to the anthracycline daunorubicin (DRC), a well-known antitumor agent in chemotherapy, by two-dimensional gel electrophoresis (2-DE). DRC is known to cause DNA damage and to affect tumor cell growth. Importantly, we aimed at investigating alterations in the protein expression pattern after first contact of the tumor cells with DRC, thus simulating a situation close to clinical chemotherapy and elucidating cell survival strategies following initial drug exposure. A concentration dependent up-regulation of a variety of proteins was observed, indicating that cell response to DRC involves multiple signaling events. Since the p53 tumor suppressor is essentially involved in the regulation of cell growth and controlled cell death (apoptosis) after cellular stress (like DNA damage), we investigated the role of p53 in DRC-resistant and -sensitive pancreas carcinoma cells by measuring p53 transcriptional transactivation activities. No differences in p53 activities were observed in response to DRC treatment in both pancreas cell lines, whereas mamma carcinoma cells (MCF-7), possessing wild-type p53, demonstrated the expected increase in p53 transcriptional transactivation activity. Hence, the tested pancreas carcinoma cells harbor a mutant, nonfunctional p53. We additionally analyzed the steady state protein levels of the cyclin dependent kinase inhibitor p21(CIP1), which is known to be involved in cell cycle control. Interestingly, p21(CIP1 )was induced by DRC in sensitive cells in a concentration dependent manner and was highest in resistant cells. In conclusion, our results suggest that the induction of proteins by DRC in pancreas carcinoma cells, as observed by 2-DE, occurs independently from p53 signaling events, but is probably associated with increased levels of p21(CIP1).