Satellite Cells – Just Now

  • The Drosophila ZAD zinc finger protein Kipferl guides Rhino to piRNA clusters
    by Lisa Baumgartner on October 4, 2022 at 10:00 am

    RNA interference systems depend on the synthesis of small RNA precursors whose sequences define the target spectrum of these silencing pathways. The Drosophila Heterochromatin Protein 1 (HP1) variant Rhino permits transcription of PIWI-interacting RNA (piRNA) precursors within transposon-rich heterochromatic loci in germline cells. Current models propose that Rhino’s specific chromatin occupancy at piRNA source loci is determined by histone marks and maternally inherited piRNAs, but also imply…

  • Chromatin remodelers HELLS, WDHD1 and BAZ1A are dynamically expressed during mouse spermatogenesis
    by Ram Prakash Yadav on October 4, 2022 at 10:00 am

    Heterochromatin is dynamically formed and organized in differentiating male germ cells, and its proper regulation is a prerequisite for normal spermatogenesis. While heterochromatin is generally transcriptionally silent, we have previously shown that major satellite repeat (MSR) DNA in the pericentric heterochromatin (PCH) is transcribed during spermatogenesis. We have also shown that DICER associates with PCH and is involved in the regulation of MSR-derived transcripts. To shed light on the…

  • Muscle injury induces a transient senescence-like state that is required for myofiber growth during muscle regeneration
    by Laura V Young on October 3, 2022 at 10:00 am

    Cellular senescence is the irreversible arrest of normally dividing cells and is driven by the cell cycle inhibitors Cdkn2a, Cdkn1a, and Trp53. Senescent cells are implicated in chronic diseases and tissue repair through their increased secretion of pro-inflammatory factors known as the senescence-associated secretory phenotype (SASP). Here, we use spatial transcriptomics and single-cell RNA sequencing (scRNAseq) to demonstrate that cells displaying senescent characteristics are “transiently”…

  • Differential expression patterns of genes associated with metabolisms, muscle growth and repair in Pectoralis major muscles of fast- and medium-growing chickens
    by Yuwares Malila on October 3, 2022 at 10:00 am

    The aim of this study was to investigate the expression of genes related to muscle growth, hypoxia and oxidative stress responses, a multi-substrate serine/threonine-protein kinase (AMPK) and AMPK-related kinases, carbohydrate metabolism, satellite cells activities and fibro- adipogenic progenitors (FAPs) in fast-growing (FG) (n = 30) and medium-growing (MG) chickens (n = 30). Pectoralis major muscles were collected at 7d, 14d, 21d, 28d, 35d and 42d of age. According to their macroscopic…

  • Retinoic acid and RARγ maintain satellite cell quiescence through regulation of translation initiation
    by Wenzhe Luo on September 29, 2022 at 10:00 am

    In adult skeletal muscle, satellite cells are in a quiescent state, which is essential for the future activation of muscle homeostasis and regeneration. Multiple studies have investigated satellite cell proliferation and differentiation, but the molecular mechanisms that safeguard the quiescence of satellite cells remain largely unknown. In this study, we purposely activated dormant satellite cells by using various stimuli and captured the in vivo-preserved features from quiescence to activation…

  • Exosome biopotentiated hydrogel restores damaged skeletal muscle in a porcine model of stress urinary incontinence
    by Tyler J Rolland on September 29, 2022 at 10:00 am

    Urinary incontinence afflicts up to 40% of adult women in the United States. Stress urinary incontinence (SUI) accounts for approximately one-third of these cases, precipitating ~200,000 surgical procedures annually. Continence is maintained through the interplay of sub-urethral support and urethral sphincter coaptation, particularly during activities that increase intra-abdominal pressure. Currently, surgical correction of SUI focuses on the re-establishment of sub-urethral support. However,…

  • Loss of full-length dystrophin expression results in major cell-autonomous abnormalities in proliferating myoblasts
    by Maxime R F Gosselin on September 27, 2022 at 10:00 am

    Duchenne muscular dystrophy (DMD) affects myofibers and muscle stem cells, causing progressive muscle degeneration and repair defects. It was unknown whether dystrophic myoblasts-the effector cells of muscle growth and regeneration-are affected. Using transcriptomic, genome-scale metabolic modelling and functional analyses, we demonstrate, for the first time, convergent abnormalities in primary mouse and human dystrophic myoblasts. In Dmd^(mdx) myoblasts lacking full-length dystrophin, the…

  • The fibrotic niche impairs satellite cell function and muscle regeneration in mouse models of Marfan syndrome
    by Meiricris Tomaz da Silva on September 27, 2022 at 10:00 am

    CONCLUSION: The fibrotic niche, caused by Fbn1 mutations, reduces the myogenic potential of satellite cells, affecting structural and functional muscle regeneration. In addition, the fibrosis inhibitor Ang-(1-7) partially counteracts satellite cell abnormalities and restores myofiber size and contractile force in regenerating muscles.

  • Bottom-associated phytoplankton bloom and its expansion in the Arctic Ocean
    by Takuhei Shiozaki on September 27, 2022 at 10:00 am

    Phytoplankton production in the Arctic Ocean is increasing due to global warming-induced sea ice loss, which is generally assessed through satellite observations of surface chlorophyll. Here we show that a diatom bloom can occur near the seafloor rather than at the surface in the open Arctic Ocean. Light can reach the seafloor underlying nutrient-rich bottom water after the spring bloom because the surface water becomes oligotrophic and increases transparency in the region of shallow Arctic…

  • Supplementation with uric and ascorbic acid protects stored red blood cells through enhancement of non-enzymatic antioxidant activity and metabolic rewiring
    by Vassilis L Tzounakas on September 26, 2022 at 10:00 am

    Redox imbalance and oxidative stress have emerged as generative causes of the structural and functional degradation of red blood cells (RBC) that happens during their hypothermic storage at blood banks. The aim of the present study was to examine whether the antioxidant enhancement of stored RBC units following uric (UA) and/or ascorbic acid (AA) supplementation can improve their storability as well as post-transfusion phenotypes and recovery by using in vitro and animal models, respectively….

  • Innate immune activation: Parallels in alcohol use disorder and Alzheimer’s disease
    by Adriana Ramos on September 26, 2022 at 10:00 am

    Alcohol use disorder is associated with systemic inflammation and organ dysfunction especially in the liver and the brain. For more than a decade, studies have highlighted alcohol abuse-mediated impairment of brain function and acceleration of neurodegeneration through inflammatory mechanisms that directly involve innate immune cells. Furthermore, recent studies indicate overlapping genetic risk factors between alcohol use and neurodegenerative disorders, specifically regarding the role of…

  • miR-106b is a novel target to promote muscle regeneration and restore satellite stem cell function in injured Duchenne dystrophic muscle
    by Lara Rodriguez-Outeiriño on September 26, 2022 at 10:00 am

    Satellite cells (SCs), muscle stem cells, display functional heterogeneity, and dramatic changes linked to their regenerative capabilities are associated with muscle-wasting diseases. SC behavior is related to endogenous expression of the myogenic transcription factor MYF5 and the propensity to enter into the cell cycle. Here, we report a role for miR-106b reinforcing MYF5 inhibition and blocking cell proliferation in a subset of highly quiescent SC population. miR-106b down-regulation occurs…

  • Assessing and enhancing migration of human myogenic progenitors using directed iPS cell differentiation and advanced tissue modelling
    by SungWoo Choi on September 26, 2022 at 10:00 am

    Muscle satellite stem cells (MuSCs) are responsible for skeletal muscle growth and regeneration. Despite their differentiation potential, human MuSCs have limited in vitro expansion and in vivo migration capacity, limiting their use in cell therapies for diseases affecting multiple skeletal muscles. Several protocols have been developed to derive MuSC-like progenitors from human induced pluripotent stem (iPS) cells (hiPSCs) to establish a source of myogenic cells with controllable proliferation…

  • Immunofluorescence Labeling of Skeletal Muscle in Development, Regeneration, and Disease
    by Marie E Esper on September 24, 2022 at 10:00 am

    Skeletal muscle is composed of long multinucleated cells, termed myofibers, that are formed through the activation and differentiation of resident muscle stem cells, called satellite cells. In healthy individuals, skeletal muscle enables voluntary locomotion while also playing a role in energy metabolism and thermoregulation. As skeletal muscle is integral to everyday processes, perturbations to skeletal muscle function can have devastating consequences. Here we describe an integral tool in…

  • Human centromere repositioning activates transcription and opens chromatin fibre structure
    by Catherine Naughton on September 24, 2022 at 10:00 am

    Human centromeres appear as constrictions on mitotic chromosomes and form a platform for kinetochore assembly in mitosis. Biophysical experiments led to a suggestion that repetitive DNA at centromeric regions form a compact scaffold necessary for function, but this was revised when neocentromeres were discovered on non-repetitive DNA. To test whether centromeres have a special chromatin structure we have analysed the architecture of a neocentromere. Centromere repositioning is accompanied by RNA…