Publications by authors named "Jesper Havelund"

A single bout of exercise improves muscle insulin sensitivity for up to 48 hours via the AMP-activated protein kinase (AMPK). Limb ischemia activates AMPK in muscle, and subsequent reperfusion enhances insulin-stimulated vasodilation, potentially eliciting a more pronounced exercise effect with reduced workload. Here, we investigated the combined effect of upper leg intermittent ischemia-reperfusion (IIR) and continuous knee-extension exercise on muscle insulin sensitivity regulation.

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Tumor necrosis factor (TNF) is highly upregulated after ischemic stroke and plays a crucial role in shaping the neuroinflammatory response that follows. Therapies aimed at inhibiting detrimental soluble (sol)TNF-TNF receptor 1 (TNFR1) signaling are gaining interest as new treatment options for neuroinflammatory conditions. We previously demonstrated that XPro1595, a selective solTNF inhibitor, decreased inflammation and improved functional outcome in the acute phase of experimental stroke.

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Nicotinamide adenine dinucleotide (NAD) is a ubiquitous electron carrier essential for energy metabolism and post-translational modification of numerous regulatory proteins. Dysregulations of NAD metabolism are widely regarded as detrimental to health, with NAD depletion commonly implicated in aging. However, the extent to which cellular NAD concentration can decline without adverse consequences remains unclear.

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The liver is essential for normal fatty acid utilization during fasting. Circulating fatty acids are taken up by hepatocytes and esterified as triacylglycerols for either oxidative metabolization and ketogenesis or export. Whereas the regulation of fatty acid oxidation in hepatocytes is well understood, the uptake and retention of non-esterified fatty acids by hepatocytes is not.

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Glucagon is secreted from the pancreatic alpha cells and regulates not only hepatic glucose production, but also hepatic lipid and amino acid metabolism. Thus, glucagon provides a switch from hepatic glucose and lipid storage towards lipid and amino acid breakdown fueling glucose production during fasting. However, the effects of genetic deletion of the glucagon receptor on lipid metabolism are unclear.

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Despite recent treatment advances, non-small cell lung cancer (NSCLC) remains one of the leading causes of cancer-related deaths worldwide, and therefore it necessitates the exploration of new therapy options. One commonly shared feature of malignant cells is their ability to hijack metabolic pathways to confer survival or proliferation. In this study, we highlight the importance of the polyol pathway (PP) in NSCLC metabolism.

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Several health-beneficial effects are associated with intake of medium-chain triacylglycerol (MCT); however, the underlying mechanisms are unknown. Furthermore, it remains uncertain whether the acute metabolic effects of MCT differ between lean individuals and individuals with obesity-and whether these effects are sustained following chronic intake. This study aimed to elucidate the postprandial physiological and metabolic effects of MCT before and after 8 days intake compared with intake of energy-matched triacylglycerol consisting of long-chain fatty acids (long-chain triacylglycerols, LCT) using a randomized cross-over design in lean individuals ( = 8) and individuals with obesity ( = 8).

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Motivation: The post-processing and analysis of large-scale untargeted metabolomics data face significant challenges due to the intricate nature of correction, filtration, imputation, and normalization steps. Manual execution across various applications often leads to inefficiencies, human-induced errors, and inconsistencies within the workflow.

Results: Addressing these issues, we introduce MetaboLink, a novel web application designed to process LC-MS metabolomics datasets combining established methodologies and offering flexibility and ease of implementation.

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The fetal development of organs and functions is vulnerable to perturbation by maternal inflammation which may increase susceptibility to disorders after birth. Because it is not well understood how the placenta and fetus respond to acute lung- inflammation, we characterize the response to maternal pulmonary lipopolysaccharide exposure across 24 h in maternal and fetal organs using multi-omics, imaging and integrative analyses. Unlike maternal organs, which mount strong inflammatory immune responses, the placenta upregulates immuno-modulatory genes, in particular the IL-6 signaling suppressor Socs3.

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Context: Given the promising effects of prolonged treatment with beta2-agonist on insulin sensitivity in animals and nondiabetic individuals, the beta2-adrenergic receptor has been proposed as a target to counter peripheral insulin resistance. On the other hand, rodent studies also reveal that beta2-agonists acutely impair insulin action, posing a potential caveat for their use in treating insulin resistance.

Objective: To assess the impact of beta2-agonist on muscle insulin action and glucose metabolism and identify the underlying mechanism(s) in 10 insulin-resistant subjects.

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Disturbances in gut microbiota are prevalent in inflammatory bowel disease (IBD), which includes ulcerative colitis (UC). However, whether these disturbances contribute to development of the disease or are a result of the disease is unclear. In pairs of human twins discordant for IBD, the healthy twin has a higher risk of developing IBD and a gut microbiota that is more similar to that of IBD patients as compared with healthy individuals.

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Pseudoexons are nonfunctional intronic sequences that can be activated by deep-intronic sequence variation. Activation increases pseudoexon inclusion in mRNA and interferes with normal gene expression. The c.

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Oncogene-induced senescence (OIS) is a persistent anti-proliferative response that acts as a barrier against malignant transformation. During OIS, cells undergo dynamic remodeling, which involves alterations in protein and organelle homeostasis through autophagy. Here, we show that ribosomes are selectively targeted for degradation by autophagy during OIS.

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Article Synopsis
  • EMT is a process that helps cancer cells spread and become resistant to treatment, making it a big challenge in fighting cancer.
  • Researchers found that short-chain fatty acids like propionate can help stop this process in lung cancer cells, making them less aggressive.
  • Propionate not only helps lung cancer cells stick together but also reduces their ability to spread in mice, showing promise for new treatments in the future.
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Hepatic lipid metabolism is highly dynamic, and disruption of several circadian transcriptional regulators results in hepatic steatosis. This includes genetic disruption of the glucocorticoid receptor (GR) as the liver develops. To address the functional role of GR in the adult liver, we used an acute hepatocyte-specific GR knockout model to study temporal hepatic lipid metabolism governed by GR at several preprandial and postprandial circadian timepoints.

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Article Synopsis
  • The study investigates how obesity during pregnancy influences maternal metabolites in early pregnancy, specifically in the first trimester.
  • Researchers analyzed maternal serum samples from 111 non-smoking women to identify metabolites associated with obesity indicators using advanced metabolomics techniques.
  • The analysis revealed 15 key metabolites linked to measures like BMI and insulin levels, with palmitoleoyl ethanolamine and N-acetyl-L-alanine being notably associated with C-peptide levels, suggesting a significant metabolic shift related to obesity in pregnant women.
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Molecular clocks in the periphery coordinate tissue-specific daily biorhythms by integrating input from the hypothalamic master clock and intracellular metabolic signals. One such key metabolic signal is the cellular concentration of NAD, which oscillates along with its biosynthetic enzyme, nicotinamide phosphoribosyltransferase (NAMPT). NAD levels feed back into the clock to influence rhythmicity of biological functions, yet whether this metabolic fine-tuning occurs ubiquitously across cell types and is a core clock feature is unknown.

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Article Synopsis
  • Scientists studied how a high-fat diet affects bones in female mice that had their ovaries removed, mimicking postmenopausal women.
  • Mice on a high-fat diet gained a lot of weight and showed poor sugar control, which negatively impacted their bone health.
  • The results suggest that both obesity and lack of estrogen make bones weaker, leading to more fat in bone marrow and less bone strength.
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Context: Glucose-dependent insulinotropic polypeptide (GIP) has been proposed to exert insulin-independent effects on lipid and bone metabolism.

Objective: We investigated the effects of a 6-day subcutaneous GIP infusion on circulating lipids, white adipose tissue (WAT), brown adipose tissue (BAT), hepatic fat content, inflammatory markers, respiratory exchange ratio (RER), and bone homeostasis in patients with type 1 diabetes.

Methods: In a randomized, placebo-controlled, double-blind, crossover study, 20 men with type 1 diabetes underwent a 6-day continuous subcutaneous infusion with GIP (6 pmol/kg/min) and placebo (saline), with an interposed 7-day washout period.

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Fasting metabolism and immunity are tightly linked; however, it is largely unknown how immune cells contribute to metabolic homeostasis during fasting in healthy subjects. Here, we combined cell-type-resolved genomics and computational approaches to map crosstalk between hepatocytes and liver macrophages during fasting. We identified the glucocorticoid receptor (GR) as a key driver of fasting-induced reprogramming of the macrophage secretome including fasting-suppressed cytokines and showed that lack of macrophage GR impaired induction of ketogenesis during fasting as well as endotoxemia.

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The transition from a fasted to a fed state is associated with extensive transcriptional remodeling in hepatocytes facilitated by hormonal- and nutritional-regulated transcription factors. Here, we use a liver-specific glucocorticoid receptor (GR) knockout (L-GRKO) model to investigate the temporal hepatic expression of GR target genes in response to feeding. Interestingly, in addition to the well-described fasting-regulated genes, we identify a subset of hepatic feeding-induced genes that requires GR for full expression.

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Article Synopsis
  • Alzheimer's Disease (AD) is a complicated illness, and scientists are exploring new ways to understand what causes it by looking at specific substances (metabolites) in our bodies.
  • In a study, researchers tested blood samples from people with AD, those with Mild Cognitive Impairment (MCI), and healthy individuals to find important differences in these substances.
  • They found six specific metabolites in blood that could help identify AD, but no significant differences were seen in extracellular vesicles (EVs), suggesting that more research is needed to use EVs effectively in studying this disease.
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PARK2 (parkin) mutations cause early-onset Parkinson's disease (PD). Parkin is an ubiquitin E3 ligase that participates in several cellular functions, including mitochondrial homeostasis. However, the specific metabolomic changes caused by parkin depletion remain unknown.

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One of the most fundamental challenges for all living organisms is to sense and respond to alternating nutritional conditions in order to adapt their metabolism and physiology to promote survival and achieve balanced growth. Here, we applied metabolomics and lipidomics to examine temporal regulation of metabolism during starvation in wild-type Caenorhabditis elegans and in animals lacking the transcription factor HLH-30. Our findings show for the first time that starvation alters the abundance of hundreds of metabolites and lipid species in a temporal- and HLH-30-dependent manner.

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Mitochondrial dysfunction after transient cerebral ischemia can be monitored by cerebral microdialysis (CMD) using changes in the lactate and pyruvate concentrations and ratio. Other metabolites associated with mitochondrial (dys)function are, e.g.

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