The aim of this study was to quantify the training effects of wearing calf-loaded wearable resistance (WR) during a netball specific warm-up in female netball athletes. Twenty-nine high school female netball athletes were matched for change of direction (COD) speed and randomly allocated to either WR training or an unloaded group. Both groups performed the same warm-up two times per week for 6 weeks, with the WR group wearing 1%-1.
View Article and Find Full Text PDFAbstractIsland vertebrates that are small on the mainland tend to be larger and exhibit tamer behavior than their mainland conspecifics-a combined set of characteristics known as "island syndrome." Such island-specific traits are often attributed to lower predation pressure on islands than on the mainland. While the morphology and behavior of island vertebrates has received significant attention, relatively few studies have compared physiological traits between island and mainland populations.
View Article and Find Full Text PDFBi-functional enzyme FicD regulates the endoplasmic reticulum chaperone BiP using AMPylation and deAMPylation during ER homeostasis and stress, respectively. Human FicD with an arginine-to-serine mutation disrupts FicD deAMPylation activity resulting in severe neonatal diabetes. We generated the mutation in mice to create a pre-clinical murine model for neonatal diabetes.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
September 2024
During homeostasis, the endoplasmic reticulum (ER) maintains productive transmembrane and secretory protein folding that is vital for proper cellular function. The ER-resident HSP70 chaperone, binding immunoglobulin protein (BiP), plays a pivotal role in sensing ER stress to activate the unfolded protein response (UPR). BiP function is regulated by the bifunctional enzyme filamentation induced by cyclic-AMP domain protein (FicD) that mediates AMPylation and deAMPylation of BiP in response to changes in ER stress.
View Article and Find Full Text PDFThe root nodules of actinorhizal plants are home to nitrogen-fixing bacterial symbionts, known as Frankia, along with a small percentage of other microorganisms. These include fungal endophytes and non-Frankia bacteria. The taxonomic and functional diversity of the microbial consortia within these root nodules is not well understood.
View Article and Find Full Text PDFThe unfolded protein response (UPR) is a cellular stress response that is activated when misfolded proteins accumulate in the endoplasmic reticulum (ER). Regulation of the UPR response must be adapted to the needs of the cell as prolonged UPR responses can result in disrupted cellular function and tissue damage. Previously, we discovered that the enzyme FicD (also known as Fic or HYPE) through its AMPylation and deAMPylation activity can modulate the UPR response via post-translational modification of BiP.
View Article and Find Full Text PDFThe unfolded protein response (UPR) is a cellular stress response that is activated when misfolded proteins accumulate in the endoplasmic reticulum (ER). The UPR elicits a signaling cascade that results in an upregulation of protein folding machinery and cell survival signals. However, prolonged UPR responses can result in elevated cellular inflammation, damage, and even cell death.
View Article and Find Full Text PDFUnlabelled: During homeostasis, the endoplasmic reticulum (ER) maintains productive transmembrane and secretory protein folding that is vital for proper cellular function. The ER-resident HSP70 chaperone, BiP, plays a pivotal role in sensing ER stress to activate the unfolded protein response (UPR). BiP function is regulated by the bifunctional enzyme FicD that mediates AMPylation and deAMPylation of BiP in response to changes in ER stress.
View Article and Find Full Text PDFMetabolic Syndrome (MetS) raises cardiovascular disease risk. Extracellular vesicles (EVs) have emerged as important mediators of insulin sensitivity, although few studies on vascular function exist in humans. We determined the effect of insulin on EVs in relation to vascular function.
View Article and Find Full Text PDFJ Appl Physiol (1985)
December 2022
Exercise has systemic health benefits in people, in part, through improving whole body insulin sensitivity. The brain is an insulin-sensitive organ that is often underdiscussed relative to skeletal muscle, liver, and adipose tissue. Although brain insulin action may have only subtle impacts on peripheral regulation of systemic glucose homeostasis, it is important for weight regulation as well as mental health.
View Article and Find Full Text PDFFungal endophytes are critical members of the plant microbiome, but their community dynamics throughout an entire growing season are underexplored. Additionally, most fungal endophyte research has centred on seed-reproducing hosts, while spore-reproducing plants also host endophytes and may be colonized by unique community members. In order to examine annual fungal endophyte community dynamics in a spore-reproducing host, we explored endophytes in a single population of ferns, Polystichum munitum, in the Pacific Northwest.
View Article and Find Full Text PDFThe proper balance of synthesis, folding, modification, and degradation of proteins, also known as protein homeostasis, is vital to cellular health and function. The unfolded protein response (UPR) is activated when the mechanisms maintaining protein homeostasis in the endoplasmic reticulum become overwhelmed. However, prolonged or strong UPR responses can result in elevated inflammation and cellular damage.
View Article and Find Full Text PDFAm J Physiol Endocrinol Metab
October 2022
Elevated extracellular vesicles (EVs) are associated with glucose dysmetabolism. However, the effects of insulin on EVs and subsequent relationships with insulin sensitivity, substrate oxidation, and inflammation are unknown. We tested the hypothesis that insulin would lower EVs and relate to insulin action.
View Article and Find Full Text PDFContext: People characterized as late chronotype have elevated type 2 diabetes and cardiovascular disease risk compared to early chronotype. It is unclear how chronotype is associated with insulin sensitivity, metabolic flexibility, or plasma TCA cycle intermediates concentration, amino acids (AA), and/or beta-oxidation.
Objective: This study examined these metabolic associations with chronotype.
Introduction: Nocturnal systolic blood pressure (SBP) dipping is independently related to cardiovascular disease risk, but it is unclear if vascular insulin sensitivity associates with SBP dipping in patients with metabolic syndrome (MetS).
Methods: Eighteen adults with MetS (ATP III criteria 3.3 ± 0.
Endoplasmic reticulum (ER) calcium (Ca ) stores are critical to proteostasis, intracellular signaling, and cellular bioenergetics. Through forward genetic screening in mice, we identified two members of a new complex, Pacs1 and Wdr37, which are required for normal ER Ca handling in lymphocytes. Deletion of Pacs1 or Wdr37 caused peripheral lymphopenia that was linked to blunted Ca release from the ER after antigen receptor stimulation.
View Article and Find Full Text PDFFront Endocrinol (Lausanne)
June 2021
Metformin and exercise independently improve glycemic control. Metformin traditionally is considered to reduce hepatic glucose production, while exercise training is thought to stimulate skeletal muscle glucose disposal. Collectively, combining treatments would lead to the anticipation for additive glucose regulatory effects.
View Article and Find Full Text PDFIsland rodents are often larger and live at higher population densities than their mainland counterparts, characteristics that have been referred to as "island syndrome". Island syndrome has been well studied, but few studies have tested for island-mainland differences in stress physiology. We evaluated island syndrome within the context of stress physiology of white-footed mice () captured from 11 islands and five mainland sites in Thousand Islands National Park, Ontario, Canada.
View Article and Find Full Text PDFObjectives: To investigate injury incidence and the influence of physical fitness parameters on the risk of severe injuries in players on rugby sevens university teams.
Design: Prospective cohort study.
Methods: Rugby players from three universities (N=104; 90M:14F; 20.
Sea otters (Enhydra lutris) inhabiting the Aleutian Islands have stabilized at low abundance levels following a decline and currently exhibit restricted habitat-utilization patterns. Possible explanations for restricted habitat use by sea otters can be classified into two fundamentally different processes, bottom-up and top-down forcing. Bottom-up hypotheses argue that changes in the availability or nutritional quality of prey resources have led to the selective use of habitats that support the highest quality prey.
View Article and Find Full Text PDFHibernation is an energy-saving adaptation that involves a profound suppression of physical activity that can continue for 6-8 months in highly seasonal environments. While immobility and disuse generate muscle loss in most mammalian species, in contrast, hibernating bears and ground squirrels demonstrate limited muscle atrophy over the prolonged periods of physical inactivity during winter, suggesting that hibernating mammals have adaptive mechanisms to prevent disuse muscle atrophy. To identify common transcriptional programmes that underlie molecular mechanisms preventing muscle loss, we conducted a large-scale gene expression screen in hind limb muscles comparing hibernating and summer-active black bears and arctic ground squirrels using custom 9600 probe cDNA microarrays.
View Article and Find Full Text PDFPhysical inactivity reduces mechanical load on the skeleton, which leads to losses of bone mass and strength in non-hibernating mammalian species. Although bears are largely inactive during hibernation, they show no loss in bone mass and strength. To obtain insight into molecular mechanisms preventing disuse bone loss, we conducted a large-scale screen of transcriptional changes in trabecular bone comparing winter hibernating and summer non-hibernating black bears using a custom 12,800 probe cDNA microarray.
View Article and Find Full Text PDFTwo chromomycin SA analogs, chromomycin SA(3) and chromomycin SA(2), along with deacetylchromomycin A(3) and five previously reported chromomycin analogs were isolated from a marine-derived Streptomyces sp. The structures of the new compounds were determined by spectroscopic methods including 1D and 2D NMR techniques, HRMS and chemical methods. Chromomycin SA(3) and chromomycin SA(2) are the first naturally occuring chromomycin analogs with truncated side-chains.
View Article and Find Full Text PDFBackground: Hibernation is an adaptive strategy to survive in highly seasonal or unpredictable environments. The molecular and genetic basis of hibernation physiology in mammals has only recently been studied using large scale genomic approaches. We analyzed gene expression in the American black bear, Ursus americanus, using a custom 12,800 cDNA probe microarray to detect differences in expression that occur in heart and liver during winter hibernation in comparison to summer active animals.
View Article and Find Full Text PDFBackground: Species of the bear family (Ursidae) are important organisms for research in molecular evolution, comparative physiology and conservation biology, but relatively little genetic sequence information is available for this group. Here we report the development and analyses of the first large scale Expressed Sequence Tag (EST) resource for the American black bear (Ursus americanus).
Results: Comprehensive analyses of molecular functions, alternative splicing, and tissue-specific expression of 38,757 black bear EST sequences were conducted using the dog genome as a reference.