MicroRNAs (miRNAs) are small, noncoding RNAs that play a critical role in regulating gene expression post-transcriptionally. They are involved in various developmental and physiological processes, and their dysregulation is linked to various diseases. Skeletal muscle-specific miRNAs, including miR-1, play a crucial role in the development and maintenance of skeletal muscle.
View Article and Find Full Text PDFA detailed understanding of molecular responses to a hypertrophic stimulus in skeletal muscle leads to therapeutic advances aimed at promoting muscle mass. To decode the molecular factors regulating skeletal muscle mass, we utilized a 24-h time course of human muscle biopsies after a bout of resistance exercise. Our findings indicate: (1) the DNA methylome response at 30 min corresponds to upregulated genes at 3 h, (2) a burst of translation- and transcription-initiation factor-coding transcripts occurs between 3 and 8 h, (3) changes to global protein-coding gene expression peaks at 8 h, (4) ribosome-related genes dominate the mRNA landscape between 8 and 24 h, (5) methylation-regulated MYC is a highly influential transcription factor throughout recovery.
View Article and Find Full Text PDFJ Adolesc Health
December 2024
Purpose: The purpose of this article is to evaluate the relationship between exposure to poor air quality (AQ) and self-reported symptoms among young adults with asthma during wildfire smoke season.
Methods: Sixty seven young adults (aged 18-26 years) completed the Asthma Control Test and reported asthma symptoms at three time points (baseline, 4 weeks, and 8 weeks) during wildfire season as part of a clinical trial. Bivariate correlations between Asthma Control Test and AQ measures were examined followed by predictive linear regression.
Major power outages have risen over the last two decades, largely due to more extreme weather conditions. However, there is a lack of knowledge on the distribution of power outages and its relationship to social vulnerability and co-occurring hazards. We examined the associations between localized outages and social vulnerability factors (demographic characteristics), controlling for environmental factors (weather), in Washington State between 2018-2021.
View Article and Find Full Text PDFRoberts et al. have provided an insightful counterpoint to our review article on the utility of the synergist ablation model. The purpose of this review is to provide some further dialogue regarding the strengths and weaknesses of the synergist ablation model.
View Article and Find Full Text PDFIn cell biology, ribosomal RNA (rRNA) 2'-methyl (2'--Me) is the most prevalent posttranscriptional chemical modification contributing to ribosome heterogeneity. The modification involves a family of small nucleolar RNAs (snoRNAs) and is specified by box C/D snoRNAs (SNORDs). Given the importance of ribosome biogenesis for skeletal muscle growth, we asked if rRNA 2'--Me in nascent ribosomes synthesized in response to a growth stimulus is an unrecognized mode of ribosome heterogeneity in muscle.
View Article and Find Full Text PDFbioRxiv
March 2024
Molecular control of recovery after exercise in muscle is temporally dynamic. A time course of biopsies around resistance exercise (RE) combined with -omics is necessary to better comprehend the molecular contributions of skeletal muscle adaptation in humans. Vastus lateralis biopsies before and 30 minutes, 3-, 8-, and 24-hours after acute RE were collected.
View Article and Find Full Text PDFOf the "Yamanaka factors" Oct3/4 , Sox2 , Klf4 , and c-Myc (OSKM), the transcription factor c-Myc ( Myc ) is the most responsive to exercise in skeletal muscle and is enriched within the muscle fiber. We hypothesize that the pulsatile induction of MYC protein after bouts of exercise can serve to epigenetically reprogram skeletal muscle toward a more resilient and functional state.
View Article and Find Full Text PDFAim: The aim of this observational study was to determine the immune status and function in young adults with cerebral palsy (CP) in comparison to typically developing individuals.
Method: Blood samples from 12 individuals with CP (five males, seven females; mean age: 25 years 1 month (5 years 9 months); age range: 19-38 years) and 17 typically developing individuals (eight males, nine females; mean age: 31 years 4 months (6 years 2 months); age range: 20-40 years) were collected before, immediately after, and 1 hour after 45 minutes of frame running or running respectively. Independent t-tests were used to compare heart rate, level of exertion, and baseline cell proportions between groups.
Function (Oxf)
December 2023
The central dogma of molecular biology dictates the general flow of molecular information from DNA that leads to a functional cellular outcome. In skeletal muscle fibers, the extent to which global myonuclear transcriptional alterations, accounting for epigenetic and post-transcriptional influences, contribute to an adaptive stress response is not clearly defined. In this investigation, we leveraged an integrated analysis of the myonucleus-specific DNA methylome and transcriptome, as well as myonuclear small RNA profiling to molecularly define the early phase of skeletal muscle fiber hypertrophy.
View Article and Find Full Text PDFMicroRNAs (miRs) control stem cell biology and fate. Ubiquitously expressed and conserved miR-16 was the first miR implicated in tumorigenesis. miR-16 is low in muscle during developmental hypertrophy and regeneration.
View Article and Find Full Text PDFAm J Phys Med Rehabil
January 2024
Objectives: The aim of the study were to (1) investigate what physical and physiological parameters are most important for Frame Running capacity, a parasport for individuals with ambulatory difficulties, and (2) determine whether Frame Running capacity can be predicted in athletes with cerebral palsy.
Design: Athletes with cerebral palsy ( N = 62, Gross Motor Classification System I-V; 2/26/11/21/2) completed a 6-min Frame Running test. Before the 6-min Frame Running test, muscle thickness, passive range of motion (hip, knee, ankle), selective motor control, and spasticity (hip, knee, ankle) were measured in both legs.
Cumulative evidence supports the hypothesis that hypoxia acts as a regulator of muscle mass. However, the underlying molecular mechanisms remain incompletely understood, particularly in human muscle. Here we examined the effect of hypoxia on signaling pathways related to ribosome biogenesis and myogenic activity following an acute bout of resistance exercise.
View Article and Find Full Text PDFIn this study, the properties of circulating extracellular vesicles (EVs) were examined in cerebral palsy (CP) and typically developed (TD) individuals at rest and after aerobic exercise, focusing on the size, concentration, and microRNA cargo of EVs. Nine adult individuals with CP performed a single exercise bout consisting of 45 min of Frame Running, and TD participants completed either 45 min of cycling ( = 10; TD EX) or were enrolled as controls with no exercise ( = 10; TD CON). Blood was drawn before and 30 min after exercise and analyzed for EV concentration, size, and microRNA content.
View Article and Find Full Text PDFObliterating skeletal muscle Orai1 expression improves muscle pathology in the mdx mouse model of DMD—could Orai1 emerge as a potential drug target?
View Article and Find Full Text PDFObjective: Self-monitoring asthma control is a key component of asthma management. Few studies have reported usability and acceptability of portable spirometry among young adults with asthma. Portable spirometry offers a practical solution to monitoring airway narrowing at home.
View Article and Find Full Text PDFObjective: The purpose of this study was to assess health-related responses to wildfire smoke on social media. We examined whether seasonal wildfire smoke is an active topic on Twitter, the correlation between fine particulate matter (PM ) and Twitter search terms, and dimensions of community-level expression to wildfire smoke through tweets.
Design: Search terms were identified using a conceptual model developed and refined by healthcare providers and public health experts.
Circulating microRNAs (miRNAs) have become increasingly popular biomarker candidates in various diseases. However, heparin-based anticoagulants might affect the detection of target miRNAs in blood samples during quantitative polymerase chain reaction (qPCR)-based analysis of miRNAs involving RNA extraction, cDNA synthesis and the polymerase catalyzed reaction. Because low-molecular-weight heparins (LMWH) are widely used in routine healthcare, we aimed to investigate whether a prophylactic dose of the LMWH tinzaparin influences qPCR-based quantification of circulating miRNAs.
View Article and Find Full Text PDFPurpose: This study aimed to explore the feasibility of using time-matched uniaxial accelerometers for measuring movement in daily life in children with cerebral palsy (CP) before and after botulinum toxin injections.
Methods: This observational study of clinical care with a pre-post design was set in the home and school environment. Participants included eleven children (4-13 years of age) with CP (GMFCS I-III).
Myc is a powerful transcription factor implicated in epigenetic reprogramming, cellular plasticity, and rapid growth as well as tumorigenesis. Cancer in skeletal muscle is extremely rare despite marked and sustained Myc induction during loading-induced hypertrophy. Here, we investigated global, actively transcribed, stable, and myonucleus-specific transcriptomes following an acute hypertrophic stimulus in mouse plantaris.
View Article and Find Full Text PDFPurpose: To determine the physiological response and association to peak oxygen uptake of the 6-minute Frame Running test (6-MFRT) in persons with cerebral palsy (CP).
Methods: Twenty-four participants with CP, Gross Motor Function Classification System II/III/IV, performed the 6-MFRT. Distance, peak heart rate (HR peak ), peak respiratory exchange ratio (RER peak ), and peak oxygen uptake ( O 2peak ) were measured.
Accurate determination of skeletal muscle size is of great importance in multiple settings including resistance exercise, aging, disease, and disuse. Ultrasound (US) measurement of muscle thickness (MT) is a method of relatively high availability and low cost. The present study aims to evaluate a multisite ultrasonographic protocol for measurement of MT with respect to reproducibility and correlation to gold-standard measurements of muscle volume (MV) with magnetic resonance imaging (MRI) in children.
View Article and Find Full Text PDFIntroduction: The ischaemic pain of acute compartment syndrome (ACS) can be difficult to discriminate from the pain linked to an associated fracture. Lacking objective measures, the decision to perform fasciotomy is based on clinical findings and performed at a low level of suspicion. Biomarkers of muscle cell damage may help to identify and monitor patients at risk, similar to current routines for patients with acute myocardial infarction.
View Article and Find Full Text PDFObjective: Frame Running (RaceRunning) allows people with moderate-to-severe mobility impairments to participate in physical activity using a 3-wheeled frame with a saddle and handlebars. The aim of this study was to investigate athlete-perceived impact of Frame Running on aspects of physical fitness, functional mobility and psychosocial outcomes.
Design: Survey.