Kristian Kiilerich's research while affiliated with IT University of Copenhagen and other places

Publications (14)

Article
In recognition of the policies of Diabetes , specifically that “[a]t the time of submission, authors should disclose details of related papers they have authored […], similar papers in press, and any …
Article
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This study aimed at determining the effects of bed rest on the skeletal muscle leptin signaling system. Deltoid and vastus lateralis muscle biopsies and blood samples were obtained from 12 healthy young men (mean ± SD, BMI 22.8 ± 2.7 kg/m(2)) before and after 7 days of bed rest. Leptin receptor isoforms (OB-Rs), suppressor of cytokine signaling 3 (...
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The aim was to assess mRNA and/or protein levels of heat shock proteins, cytokines, growth regulating, and metabolic proteins in myalgic muscle at rest and in response to work tasks and prolonged exercise training. A randomized controlled trial included 28 females with trapezius myalgia and 16 healthy controls. Those with myalgia performed ~7 hrs r...
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To elucidate the molecular mechanisms behind physical inactivity-induced insulin resistance in skeletal muscle, 12 young, healthy male subjects completed 7 days of bed rest with vastus lateralis muscle biopsies obtained before and after. In six of the subjects, muscle biopsies were taken from both legs before and after a 3-h hyperinsulinemic euglyc...
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The transcriptional coactivator peroxisome proliferator-activated receptor (PPAR)-γ coactivator (PGC)-1α plays a role in regulation of several metabolic pathways. By use of whole body PGC-1α knockout (KO) mice, we investigated the role of PGC-1α in fasting, acute exercise and exercise training-induced regulation of key proteins in gluconeogenesis a...
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The aim was to test the hypothesis that 7 days of bed rest reduces mitochondrial number and expression and activity of oxidative proteins in human skeletal muscle but that exercise-induced intracellular signaling as well as mRNA and microRNA (miR) responses are maintained after bed rest. Twelve young, healthy male subjects completed 7 days of bed r...
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To test the hypothesis that physical inactivity impairs the exercise-induced modulation of pyruvate dehydrogenase (PDH), six healthy normally physically active male subjects completed 7 days of bed rest. Before and immediately after the bed rest, the subjects completed an oral glucose tolerance test (OGTT) and a one-legged knee extensor exercise bo...
Article
The study's purpose was to examine the effects of a short-term period with intensified training or training cessation of trained soccer players on VO(2) kinetics at 75% maximal aerobic speed, oxidative enzymes, and performance in repeated high-intensity exercise. After the last match of the season, 18 elite soccer players were, for a 2-wk period, a...
Article
The aim of this study was to test the hypothesis that interleukin (IL)-6 plays a role in exercise-induced peroxisome proliferator-activated receptor γ co-activator (PGC)-1α and tumor necrosis factor (TNF)-α mRNA responses in skeletal muscle and to examine the potential IL-6-mediated AMP-activated protein kinase (AMPK) regulation in these responses....
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The aim of this study was to test whether the transcriptional coactivator peroxisome proliferator-activated receptor (PPAR)-γ coactivator (PGC)1α regulates the content of pyruvate dehydrogenase (PDH)-E1α and influences PDH activity through regulation of pyruvate dehydrogenase kinase-4 (PDK4) expression and subsequently PDH phosphorylation. PGC-1α w...
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Lifestyle-related diseases are rapidly increasing at least in part due to less physical activity. The health beneficial effects of regular physical activity include metabolic adaptations in skeletal muscle, which are thought to be elicited by cumulative effects of transient gene responses to each single exercise, but how is this regulated? A potent...
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To test the hypothesis that free fatty acid (FFA) and muscle glycogen modify exercise-induced regulation of PDH (pyruvate dehydrogenase) in human skeletal muscle through regulation of PDK4 expression. On two occasions, healthy male subjects lowered (by exercise) muscle glycogen in one leg (LOW) relative to the contra-lateral leg (CON) the day befor...
Article
The aim of the present study was to test the hypothesis that peroxisome proliferator activated receptor-gamma coactivator (PGC) 1alpha is required for exercise-induced adaptive gene responses in skeletal muscle. Whole body PGC-1alpha knockout (KO) and littermate wild-type (WT) mice performed a single treadmill-running exercise bout. Soleus and whit...
Article
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To test the hypothesis that pyruvate dehydrogenase (PDH) is differentially regulated in specific human muscles, regulation of PDH was examined in triceps, deltoid, and vastus lateralis at rest and during intense exercise. To elicit considerable glycogen use, subjects performed 30 min of exhaustive arm cycling on two occasions and leg cycling exerci...

Citations

... Prolonged bed rest is associated with an increased risk of post-operative complications after surgery. Prolonged immobility has been shown to increase the risk of venous thromboembo‐ lism [30], result in loss of muscle bulk and strength [31], increase insulin resistance [32], reduce pulmonary function and tissue oxygenation and increase levels of hospital associated depres‐ sion [33]. All of these complications increase patient length of hospital stay (LOS) and, in some cases such as venous thromboembolisation and decreased pulmonary function, can threaten life. ...
... Furthermore, systemic changes in circulating proteins produced by adipose tissue (such as increased leptin and adiponectin) have been reported with both short (7-14 days) and longterm (60 days) bed rest (19)(20)(21). Thus, there is some indication that adipose tissue may be affected by physical inactivity, but existing observations come from relatively short-term studies and, to date, none have undertaken a broad characterisation of adipose tissue in response to bed rest. ...
... Despite that oxidative stress is involved in NMDs, and exercise induces ROS production, some types of training increase mRNA levels and the expression of metabolic muscle proteins. In particular, a moderate and regular physical exercise has been suggested as non-pharmacological treatment for the NMDs (Sjøgaard et al., 2013). ...
... 12,26 Furthermore, bed rest has been demonstrated to diminish glucose uptake and insulin signaling by insulindependent tissues. 27 The patients in this study were on combined nutrition with oral intake and enteral and parenteral feeding. The individualized SPN provides up to 250 g/d of glucose and up to 30% of total calories from lipid emulsions, which may cause glucose overload and hypertriglyceridemia, which contribute to HG. Addition-ally, the infusion rate is another significant predictor of HG in patients during PN. ...
... As discussed, PGC-1α is a major activator of mitochondrial biogenesis and as such improved mitochondrial function/turnover may mediate the beneficial effects of exercise on hepatic function. This is supported by several studies [135][136][137]. ...
... Beyond the impact of disuse on myofibrillar proteins and skeletal muscle atrophy, bed rest evokes substantial losses in several proteins, found in skeletal muscle, not directly involved in the contractile process. Specifically, 7 days of bed rest reduced metabolic protein content as evidenced by a 15% reduction in mitochondrial DNA/nuclear DNA content, a 45% reduction in hexokinase and sirtuin 1 protein content, and an 8% reduction in 3-hydroxyacyl-CoA dehydrogenase and citrate synthase activity (218). Downregulation of several enzymes associated with oxidative (malate dehydrogenase) and glycolytic metabolism (lactate dehydrogenase), along with creatine kinase, indicates a general impairment in energy metabolism during disuse (198,219). ...
... Indeed, it was demonstrated that merely 1 wk of bed rest leads to a 1.4-kg loss of muscle mass, as assessed via dual-energy X-ray absorptiometry (DXA), in healthy, young individuals (47). This muscle atrophy is accompanied by a severe metabolic decline, such that 7-9 days of strict bed rest leads to an ϳ30% decline in insulin sensitivity and glucose tolerance (2,14,47,84,97,143), which cannot be explained by bed rest-induced changes in plasma volume (33,36). This demonstrates that interventional strategies should not only focus on preventing muscle loss during a period of disuse but also aim to attenuate the decline in metabolic health that occurs during disuse in a bed rest model. ...
... Lastly, IL-6-STAT3 signalling may contribute to some muscular adaptations that occur after training, such as the induction of mitochondrial biogenesis and increased mitochondrial activity 77 driven by PGC-1α (ref. 78 ). Intriguingly, this effect appears to be restricted to specific muscle tissues 79 . ...
... Isolated HIIT-SM have been performed between 9 and 21 days, during which 9 to 24 sessions were conducted [9][10][11][12][13][17][18][19]. This concept is discussed to promise a rapid increase in performance, but usually reduces the total training volume during this period of about 30% compared to regular training weeks, especially for elite athletes [20]. Although multiple studies have demonstrated the effectiveness of HIIT-SM to improve endurance performance [9][10][11][12][13] others have been less conclusive [16][17][18][19]. ...
... Although we were not able to detect significant alterations in PDK levels in NSCs upon 24 h of TUDCA treatment (data not shown), we cannot exclude that TUDCA might reduce PDK levels at early time-points. On the other hand, PCG1-α, a major player of mitochondria biogenesis, is capable of increasing PDHE1-α protein content (Kiilerich et al., 2010). Thus, it is tempting to speculate that TUDCAinduced upregulation of PDHE1-α could be linked with the downregulation of ACAT1 protein expression and/or its already described effect on PCG1-α, a master regulator of mitochondrial biomass and activity Soares et al., 2018). ...