Search results for "Myogenesi"

Expression of the rat connexin 39 (rCx39) gene in myoblasts and myotubes in developing and regenerating skeletal muscles: an in situ hybridization st…

2005

We report a detailed analysis of the expression pattern of the recently identified rat connexin gene, named rat connexin 39 (rCx39), both during embryonic development and in adult life. Qualitative and quantitative reverse transcription/polymerase chain reaction analysis showed intense expression of rCx39 restricted to differentiating skeletal muscles, with a peak of expression detected at 18 days of embryonic life, followed by a rapid decline to undetectable levels within the first week of postnatal life. A combination of the in situ hybridization technique for the detection of rCx39 mRNA and immunohistochemistry for myogenin, a myoblast-specific marker, allowed us to establish that the mR…

Neonatal form of nemaline myopathy, muscle immaturity, and a microvascular injury.

1990

An infant with a neonatal form of nemaline myopathy showed ultrastructural features of muscle immaturity. Immaturity was characterized by an abnormal presence of myotubes, as well as cells in clusters within a common basement membrane and a great number of satellite cells adhering to very small muscle fibers. In addition, degenerative changes and a severe microvascular lesion were observed. The pathologic findings in the muscle of this patient were those of neonatal nemaline myopathy complicating severe microvascular injury, possibly induced by an unknown toxic agent. ( J Child Neurol 1990;5:122-126).

2020

Skeletal muscle atrophy is characterized by a decrease in muscle fiber size as a result of a decreased protein synthesis, which leads to degradation of contractile muscle fibers. It can occur after denervation and immobilization, and glucocorticoids (GCs) may also increase protein breakdown contributing to the loss of muscle mass and myofibrillar proteins. GCs are already used in vitro to induce atrophic conditions, but until now no studies with primary human skeletal muscle existed. Therefore, this study deals with the effects of the GC dexamethasone (dex) on primary human myoblasts and myotubes. After incubation with 1, 10, and 100 µM dex for 48 and 72 h, gene and protein expression analy…

The potassium channels TASK2 and TREK1 regulate functional differentiation of murine skeletal muscle cells.

2015

Two-pore domain potassium (K2P) channels influence basic cellular parameters such as resting membrane potential, cellular excitability, or intracellular Ca2+-concentration [Ca2+]i. While the physiological importance of K2P channels in different organ systems (e.g., heart, central nervous system, or immune system) has become increasingly clear over the last decade, their expression profile and functional role in skeletal muscle cells (SkMC) remain largely unknown. The mouse SkMC cell line C2C12, wild-type mouse muscle tissue, and primary mouse muscle cells (PMMs) were analyzed using quantitative PCR, Western blotting, and immunohistochemical stainings as well as functional analysis includin…

Arsenic promotes NF-Κb-mediated fibroblast dysfunction and matrix remodeling to impair muscle stem cell function

2016

Abstract Arsenic is a global health hazard that impacts over 140 million individuals worldwide. Epidemiological studies reveal prominent muscle dysfunction and mobility declines following arsenic exposure; yet, mechanisms underlying such declines are unknown. The objective of this study was to test the novel hypothesis that arsenic drives a maladaptive fibroblast phenotype to promote pathogenic myomatrix remodeling and compromise the muscle stem (satellite) cell (MuSC) niche. Mice were exposed to environmentally relevant levels of arsenic in drinking water before receiving a local muscle injury. Arsenic-exposed muscles displayed pathogenic matrix remodeling, defective myofiber regeneration …

PROX1 transcription factor controls rhabdomyosarcoma growth, stemness, myogenic properties and therapeutic targets

2022

Funding Information: ACKNOWLEDGMENTS. We would like to thank Dr. Tuomas Tammela and Dr. Monika Ehnmann for providing RMS cell lines and Dr. Jenny Högström for discussions and comments during the project. Kirsi Mattinen, Jefim Brodkin, Maxime Laird, Manon Gruchet, Ilse Paetau, Tanja Laakkonen, and Tapio Tainola are acknowledged for their excellent technical help. We also thank the Laboratory Animal Center at the University of Helsinki for expert animal care, the Biomedicum Imaging Unit for microscope support, the Biomedicum Functional Genomics Unit for the RNAseq experiments and the FIMM Technology Centre High Throughput Biomedicine for the drug sensitivity and resistance testing. Our first …

The early response of αB-crystallin to a single bout of aerobic exercise in mouse skeletal muscles depends upon fiber oxidative features

2019

Besides its substantial role in eye lens, αB-crystallin (HSPB5) retains fundamental function in striated muscle during physiological or pathological modifications. In this study, we aimed to analyse the cellular and molecular factors driving the functional response of HSPB5 protein in different muscles from mice subjected to an acute bout of non-damaging endurance exercise or in C2C12 myocytes upon exposure to pro-oxidant environment, chosen as “in vivo” and “in vitro” models of a physiological stressing conditions, respectively.To this end, red (GR) and white gastrocnemius (GW), as sources of slow-oxidative and fast-glycolytic/oxidative fibers, as well as the soleus (SOL), mainly composed …

Murine muscle engineered from dermal precursors: an in vitro model for skeletal muscle generation, degeneration and fatty infiltration.

2013

Skeletal muscle can be engineered by converting dermal precursors into muscle progenitors and differentiated myocytes. However, the efficiency of muscle development remains relatively low and it is currently unclear if this is due to poor characterization of the myogenic precursors, the protocols used for cell differentiation, or a combination of both. In this study, we characterized myogenic precursors present in murine dermospheres, and evaluated mature myotubes grown in a novel three-dimensional culture system. After 5-7 days of differentiation, we observed isolated, twitching myotubes followed by spontaneous contractions of the entire tissue-engineered muscle construct on an extracellul…

Absence of dysferlin alters myogenin expression and delays human muscle differentiation 'in vitro'

2006

Mutations in dysferlin cause a type of muscular dystrophy known as dysferlinopathy. Dysferlin may be involved in muscle repair and differentiation. We compared normal human skeletal muscle cultures expressing dysferlin with muscle cultures from dysferlinopathy patients. We quantified the fusion index of myoblasts as a measure of muscle development and conducted optic and electronic microscopy, immunofluorescence, Western blot, flow cytometry, and real-time PCR at different developmental stages. Short interference RNA was used to corroborate the results obtained in dysferlin-deficient cultures. A luciferase reporter assay was performed to study myogenin activity in dysferlin-deficient cultur…

Exercise-Induced Activation and Translocation of αB-Crystallin in Skeletal Muscle Depends upon Fiber Type and Oxidative Stress

2016

Alpha B-crystallin (CRYAB) is a member of the small heat shock proteins implicated in various biological functions, particularly in skeletal muscle tissue [1], where it results to be modulated following exercise-induced reactive oxygen species (ROS) [2]. In this work we aimed to analyse the CRYAB response to acute exercise with respect muscle fiber composition and to identify the underlying molecular mechanism by the utilization of the C2C12 “in vitro” cellular model. Our results highlighted as acute exercise determines a specific increase of phospho-CRYAB both in the red, but not white, gastrocnemius (GS), with an higher amount of oxidative and oxidative-glycolytic fibers, and in soleus (S…