Abstract Reactive oxygen species (ROS) act as intracellular compartmentalized second messengers, mediating metabolic stress-adaptation. In skeletal muscle fibers, ROS have been suggested to stimulate glucose transporter 4 (GLUT4)-dependent transport during artificially evoked contraction ex vivo, but whether myocellular production is stimulated by in vivo exercise control metabolism unclear. Here, we combined humans and mice with fluorescent dyes, genetically-encoded biosensors, NADPH...

Abstract Background Skeletal muscle wasting is often associated with insulin resistance. A major regulator of mass the transforming growth factor β (TGF‐β) superfamily, including activin A, which causes atrophy. TGF‐β superfamily ligands also negatively regulate insulin‐sensitive proteins, but whether this pathway contributes to action remains be determined. Methods To elucidate if action, we used an adeno‐associated virus gene editing approach overexpress inhibitor, follistatin (Fst288), in...

Reactive oxygen species (ROS) have been proposed as signaling molecules mediating exercise training adaptation, but the ROS source has remained unclear. This study aimed to investigate if increased NADPH oxidase (NOX)2-dependent activity during is required for long-term high-intensity interval (HIIT) in skeletal muscle using a mouse model lacking functional NOX2 complex due absent p47phox (Ncf1) subunit expression (ncf1* mutation).HIIT was investigated after an acute bout of and chronic...

Microtubules serve as tracks for long-range intracellular trafficking of glucose transporter 4 (GLUT4), but the role this process in skeletal muscle and insulin resistance is unclear. Here, we used fixed live-cell imaging to study microtubule-based GLUT4 human mouse fibers L6 rat cells. We found localized on microtubules fibers. Pharmacological microtubule disruption using Nocodazole (Noco) prevented depleted GLUT4-enriched structures at nucleation sites a fully reversible manner. Using...

Abstract Background Metabolic dysfunction and cachexia are associated with poor cancer prognosis. With no pharmacological treatments, it is crucial to define the molecular mechanisms causing cancer‐induced metabolic cachexia. Adenosine monophosphate‐activated protein kinase (AMPK) connects muscle mass regulation. As AMPK could be a potential treatment target, important determine function for in cancer‐associated We therefore established AMPK's roles dysfunction, insulin resistance Methods In...

Key points Exercise is a potent physiological stimulus to clear blood glucose from the circulation into skeletal muscle. The mammalian target of rapamycin complex 2 (mTORC2) an important regulator muscle uptake in response insulin stimulation. Here we report for first time that activity mTORC2 mouse increases during exercise. We further show exercise decreased lacks activity. also provide novel identifications new substrates Abstract insulin‐resistant Thus, elucidating signalling network may...

Abstract Activation of the sympathetic nervous system causes pronounced metabolic changes that are mediated by multiple adrenergic receptor subtypes. Systemic treatment with β 2- agonists results in beneficial effects, including improved glucose homeostasis. To elucidate underlying cellular and molecular mechanisms, we chronically treated wild-type mice several newly developed mutant mouse strains clenbuterol, a selective 2 -adrenergic agonist. Clenbuterol administration caused improvements...

For three-dimensional (3D) bioprinting to fulfill its promise and enable the automated fabrication of complex tissue-mimicking constructs, there is a need for developing bioinks that are not only printable biocompatible but also have integrated cell-instructive properties. Toward this goal, we here present scalable technique generating nanofiber 3D printing inks with unique tissue-guiding capabilities. Our core methodology relies on tailoring size dispersibility cellulose fibrils through...

The production of reactive oxygen species (ROS) by NADPH oxidase (NOX) 2 has been linked to both insulin resistance and exercise training adaptations in skeletal muscle. This study explores the previously unexamined role NOX2 interplay between diet-induced (ET). Using a mouse model that harbors point mutation essential regulatory subunit, p47phox (Ncf1*), we investigated impact this on various metabolic adaptations. Wild-type (WT) Ncf1* mice were assigned three groups: chow diet, 60% energy...

Abstract The kinases AMPK, and mTOR as part of either mTORC1 or mTORC2, are major orchestrators cellular growth metabolism. Phosphorylation Ser1261 is reportedly stimulated by both insulin AMPK activation a regulator mTORC2 activity. Intrigued the possibilities that might be convergence point between signaling in skeletal muscle, we investigated regulation function this site using combination human exercise, transgenic mouse, cell culture models. phosphorylation on did not respond to any our...

AMP-activated protein kinase (AMPK) occurs as heterotrimeric complexes in which a catalytic subunit (α1/α2) is bound to one of two β subunits (β1/β2) and three γ (γ1/γ2/γ3). The ability selectively activate specific isoforms would be useful research tool promising strategy combat diseases such cancer Type 2 diabetes. We report that the AMPK activator PT-1 increased activity γ1- but not γ3-containing incubated mouse muscle. AMPK-dependent phosphorylation autophagy-regulating ULK1 (unc-51-like...

Exercise is a cornerstone in the management of skeletal muscle insulin-resistance. A well-established benefit single bout exercise increased insulin sensitivity for hours post-exercise previously exercised musculature. Although rodent studies suggest that insulin-sensitization phenomenon involves enhanced insulin-stimulated GLUT4 cell surface translocation and might involve intramuscular redistribution GLUT4, conservation to humans unknown. Healthy young males underwent an...

High-intensity muscle contractions (HiMCs) are known to increase c-Myc expression that is stimulate ribosome biogenesis and protein synthesis in most cells. However, although mRNA transcription translation have been shown be upregulated following resistance exercise concomitantly with increased biogenesis, this connection has not tested directly. We investigated the effect of adeno-associated virus (AAV)-mediated overexpression, or without fasting percutaneous electrical stimulation-induced...

Exercise increases muscle glucose uptake independently of insulin signaling and represents a cornerstone for the prevention metabolic disorders. Pharmacological activation exercise-responsive AMPK in skeletal has been proven successful as therapeutic approach to treat disorders by improving homeostasis through regulation uptake. However, conflicting observations cloud proposed role necessary regulator during exercise. We show that human absence exercise exercise-stimulated AMPKγ3 activity...

AMP-activated protein kinase (AMPK)-dependent Raptor Ser792 phosphorylation does not influence mechanistic target of rapamycin complex 1 (mTORC1)-S6K1 activation by intense muscle contraction. α2 -AMPK activity-deficient mice have lower contraction-stimulated synthesis. Increasing glycogen activates mTORC1-S6K1. Normalizing content rescues reduced synthesis in AMPK-deficient mice.The mechansitic signalling pathway regulates growth-related and is antagonized (AMPK) multiple cell types....

Key points Muscle contractions increase protein synthesis in a mechanistic target of rapamycin (mTOR)‐dependent manner, yet it is unclear which/how mTOR complexes regulate muscle synthesis. We investigated the requirement Complex 2 (mTORC2) contraction‐stimulated mTORC2 inhibition by muscle‐specific Rictor knockout (Rictor mKO) did not prevent contraction‐induced Rapamycin prevented mKO but wild‐type mice. Abstract Protein increases following contractions. Previous studies have shown that...

Studies in skeletal muscle cell cultures suggest that the cortical actin cytoskeleton is a major requirement for insulin-stimulated glucose transport, implicating β-actin isoform, which many types main isoform. However, it not clear plays such role mature muscle. Neither dependency of transport on nor reorganization upon have been tested To investigate fully differentiated muscle, we performed detailed characterization wild type and muscle-specific knockout (KO) mice. The effects KO were...

Skeletal muscle (SKM) insulin resistance plays a central role in the pathogenesis of type 2 diabetes. Because G-protein–coupled receptors (GPCRs) represent excellent drug targets, we hypothesized that activation specific functional classes SKM GPCRs might lead to improved glucose homeostasis At present, little is known about vivo metabolic roles various distinct GPCR signaling pathways operative SKM. In this study, tested hypothesis selective Gq can improve uptake and whole-body under...

Muscle-specific genetic ablation of p21-activated kinase (PAK)2, but not whole-body PAK1 knockout, impairs glucose tolerance in mice. Insulin-stimulated uptake partly relies on PAK2 glycolytic extensor digitorum longus muscle By contrast to previous reports, is dispensable for insulin-stimulated mouse muscle.The group I (PAK) isoforms and are activated response insulin skeletal PAK1/2 signalling impaired insulin-resistant human muscle. Interestingly, has been suggested be required...

The small molecule kinase inhibitor SBI-0206965 was originally described as a specific of ULK1/2. More recently, it reported to effectively inhibit AMPK and several studies now report its use an inhibitor. Currently, we investigated the specificity in incubated mouse skeletal muscle, measuring effect on analog 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR)-stimulated AMPK-dependent glucose transport insulin-stimulated AMPK-independent uptake. Pre-treatment with 10 µM for 50 min...

Metabolic dysfunction and insulin resistance are emerging as hallmarks of cancer cachexia, impair prognosis. Yet, the molecular mechanisms underlying impaired metabolic regulation not fully understood. To elucidate behind cancer-induced in muscle, we isolated extensor digitorum longus (EDL) soleus muscles from Lewis Lung Carcinoma tumor-bearing mice. Three weeks after tumor inoculation, were stimulated with or without a submaximal dose (1.5 nM). Glucose transport was measured using...

Aim Muscle contraction stimulates skeletal muscle glucose transport. Since it occurs independently of insulin, is an important alternative pathway to increase transport in insulin-resistant states, but the intracellular signaling mechanisms are not fully understood. activates group I p21-activated kinases (PAKs) mouse and human muscle. PAK1 PAK2 downstream targets Rac1, which a key regulator contraction-stimulated Thus, could be effectors Rac1 The current study aimed test hypothesis that...

Chronic ad libitum low protein-high carbohydrate diet (LPHC) increases health- and life-span in mice. A periodized (p) LPHC regimen would be a more practical long-term human lifestyle intervention, but the metabolic benefits of pLPHC are not known. Also, interactions between exercise training have been investigated. Presently, we aimed to provide proof-of-concept data mice efficacy explore potential with concurrent training. detailed phenotypic molecular characterization undergoing different...

New Findings What is the central question of this study? Resolving mechanism(s) leading to glucose transporter 4 (GLUT4) translocation muscle surface membrane has great therapeutic potential. However, measurement GLUT4 technically challenging. Here, we asked whether electroporation GLUT4‐7 myc ‐GFP into skeletal could be used as a tool study in vivo . main finding and its importance? By acutely inducing expression muscle, verified that exercise AICAR stimulation increased presence sarcolemma...