Publications by authors named "Laerke Bertholdt"

White adipose tissue is a major energy reserve for the body and is essential for providing fatty acids for other tissues when needed. Skeletal muscle interleukin-6 (IL-6) has been shown to be secreted from the working muscle and has been suggested to signal to adipose tissue and enhance lipolysis. The aim of the present study was to investigate the role of skeletal muscle IL-6 in visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) lipolysis and glyceroneogenesis with prolonged moderate-intensity exercise and high-intensity exercise in mice.

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The present study aimed at investigating fasting-induced responses in regulators and markers of autophagy in vastus lateralis muscle from untrained and trained human subjects. Untrained and trained subjects (based on maximum oxygen uptake, muscle citrate synthase activity, and oxidative phosphorylation protein level) fasted for 36 h with vastus lateralis muscle biopsies obtained at 2, 12, 24, and 36 h after a standardized meal. Fasting reduced ( P < 0.

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The liver and adipose tissue are important tissues in whole-body metabolic regulation during fasting. Interleukin 6 (IL-6) is a cytokine shown to be secreted from contracting muscle in humans and suggested to signal to the liver and adipose tissue. Furthermore, skeletal muscle IL-6 has been proposed to play a role during fasting.

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The aim of the present study was to examine the influence of training state on fasting-induced skeletal muscle pyruvate dehydrogenase (PDH) regulation, including PDH phosphorylation. Trained and untrained subjects, matched for skeletal muscle CS activity and OXPHOS protein, fasted for 36 h after receiving a standardized meal. Respiratory exchange ratio (RER) was measured and blood as well as vastus lateralis muscle biopsies were obtained 2, 12, 24, and 36 h after the meal.

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An acute bout of exercise imposes a major challenge on whole-body metabolism and metabolic adjustments are needed in multiple tissues during recovery to reestablish metabolic homeostasis. It is currently unresolved how this regulation is orchestrated between tissues. This study was undertaken to clarify the role of skeletal muscle derived interleukin 6 (IL-6) in the coordination of the metabolic responses during recovery from acute exercise.

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Recruitment of fatty acids from adipose tissue is increased during fasting. However, the molecular mechanisms behind fasting-induced metabolic regulation in human adipose tissue and the potential impact of training state in this are unknown. Therefore the aim of the present study was to investigate 1) fasting-induced regulation of lipolysis and glyceroneogenesis in human adipose tissue as well as 2) the impact of training state on basal oxidative capacity and fasting-induced metabolic regulation in human adipose tissue.

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High-fat diet (HFD) induces several changes to the pathways regulating energy homeostasis and changes the expression of the hepatic cytochrome p450 (Cyp) enzyme-system. Despite these pervious findings, it is still unclear how the effects of HFD and especially HFD in combination with treadmill running affect hepatic Cyp expression. In this study, we investigated the mRNA and protein expression of selected Cyp's in mice subjected to 16 weeks of HFD and treadmill running.

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The gene expression of the cytochrome P450 (CYP) enzyme family is regulated by numerous factors. Fasting has been shown to induce increased hepatic CYP mRNA in both humans and animals. However, the coordinated regulation of CYP, CYP-regulating transcription factors, and transcriptional co-factors in the liver linking energy metabolism to detoxification has never been investigated.

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Pyruvate dehydrogenase (PDH) is the gateway enzyme for carbohydrate-derived pyruvate feeding into the TCA cycle. PDH may play a central role in regulating substrate shifts during exercise, but the influence of training state on PDH regulation during exercise is not fully elucidated. The purpose of this study was to investigate the impact of training state on post-translational regulation of PDHa activity during submaximal and exhaustive exercise.

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The liver is essential in maintaining and regulating glucose homeostasis during prolonged exercise. IL-6 has been shown to be secreted from skeletal muscle during exercise and has been suggested to signal to the liver. Therefore, the aim of this study was to investigate the role of skeletal muscle IL-6 on hepatic glucose regulation and substrate choice during prolonged exercise.

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Fasting prompts a metabolic shift in substrate utilization from carbohydrate to predominant fat oxidation in skeletal muscle, and pyruvate dehydrogenase (PDH) is seen as a controlling link between the competitive oxidation of carbohydrate and fat during metabolic challenges like fasting. Interleukin (IL)-6 has been proposed to be released from muscle with concomitant effects on both glucose and fat utilization. The aim was to test the hypothesis that muscle IL-6 has a regulatory impact on fasting-induced suppression of skeletal muscle PDH.

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Pyruvate dehydrogenase (PDH) plays a key role in the regulation of skeletal muscle substrate utilization. IL-6 is produced in skeletal muscle during exercise in a duration dependent manner and has been reported to increase whole body fatty acid oxidation, muscle glucose uptake and decrease PDHa activity in skeletal muscle of fed mice. The aim of the present study was to examine whether muscle IL-6 contributes to exercise-induced PDH regulation in skeletal muscle.

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Interleukin (IL)-6 is released from skeletal muscle (SkM) during exercise and has been shown to affect hepatic metabolism. It is, however, unknown whether SkM IL-6 is involved in the regulation of exercise training-induced counteraction of changes in carbohydrate and lipid metabolism in the liver in response to high-fat diet (HFD) feeding. Male SkM-specific IL-6 KO (MKO) and Floxed mice were subjected to Chow diet, HFD or HFD combined with exercise training (HFD ExTr) for 16 weeks.

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Objective: To investigate the role of skeletal muscle (SkM) interleukin (IL)-6 in the regulation of adipose tissue metabolism.

Methods: Muscle-specific IL-6 knockout (IL-6 MKO) and IL-6(loxP/loxP) (Floxed) mice were subjected to standard rodent diet (Chow), high-fat diet (HFD), or HFD in combination with exercise training (HFD ExTr) for 16 weeks.

Results: Total fat mass increased (P < 0.

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