ABSTRACT
Title
Role of annexin A1 in mouse myoblast cell differentiation
Authors
V. Bizzarro1,2, B. Fontanella1, S. Franceschelli1, M. Pirozzi3, H. Christian4, L. Parente1, A. Petrella1
1Department of Pharmaceutical and Biomedical Sciences, University of Salerno, Salerno, Italy
2Stem Cells and Development, Dept. of Developmental Biology, Pasteur Institute, CNRS URA 2578, Paris, France
3Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy.
4 Laboratory for Cellular Endocrinology, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
1Department of Pharmaceutical and Biomedical Sciences, University of Salerno, Salerno, Italy
2Stem Cells and Development, Dept. of Developmental Biology, Pasteur Institute, CNRS URA 2578, Paris, France
3Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy.
4 Laboratory for Cellular Endocrinology, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
Abstract
Annexin A1 (ANXA1, lipocortin-1) is the first characterized member of the annexin superfamily of proteins, so called since their main property is to bind (i.e. to annex) to cellular membranes in a Ca2+-dependent manner. ANXA1 has been involved in a broad range of molecular and cellular processes, including anti-inflammatory signalling, kinase activities in signal transduction, maintenance of cytoskeleton and extracellular matrix integrity, tissue growth, apoptosis and differentiation. On the basis of these evidences, we investigated the expression and the role of ANXA1 in an in vitro model, using the C2C12 mouse myoblast cell line and in an in vivo model using Tg:Pax7nGFP mice.
The results show that ANXA1 expression increases during differentiation and that the down-regulation of ANXA1 significantly inhibited the differentiation process. ANXA1 is expressed in vivo in both quiescent and activated satellite cells and its expression increases in activated satellite cells. Furthermore, ANXA1 is highly localized in the cells that migrate in the lumen of regenerating fibers after an acute injury. After 3 days of differentiation, ANXA1 translocatesat C2C12 plasma membrane and it is secreted in the culture medium of 5 days of differentiation.
Endogenous ANXA1 co-localized with actin fibers at the protruding ends of undifferentiated but not differentiated cells suggesting a role of the protein in cell migration via a possible FPR receptor activation. Furthermore, ANXA1 neutralizing antibody reduced MyHC expression, decreased myotube formation and significantly inhibited cell migration.
In a muscle single fiber ex vivo system ANXA1 seems to localize mainly on Pax7-positive cell plasma membrane proximity while an ANXA1 neutralizing antibody seems to inhibit satellite cell migration.
The data reported here suggest for the first time that ANXA1 has a role in skeletal muscle differentiation as it does in other tissues and models. Thus modulating the migration of satellite cells, ANXA1 may contribute to the regeneration of skeletal muscle tissue.
The results show that ANXA1 expression increases during differentiation and that the down-regulation of ANXA1 significantly inhibited the differentiation process. ANXA1 is expressed in vivo in both quiescent and activated satellite cells and its expression increases in activated satellite cells. Furthermore, ANXA1 is highly localized in the cells that migrate in the lumen of regenerating fibers after an acute injury. After 3 days of differentiation, ANXA1 translocatesat C2C12 plasma membrane and it is secreted in the culture medium of 5 days of differentiation.
Endogenous ANXA1 co-localized with actin fibers at the protruding ends of undifferentiated but not differentiated cells suggesting a role of the protein in cell migration via a possible FPR receptor activation. Furthermore, ANXA1 neutralizing antibody reduced MyHC expression, decreased myotube formation and significantly inhibited cell migration.
In a muscle single fiber ex vivo system ANXA1 seems to localize mainly on Pax7-positive cell plasma membrane proximity while an ANXA1 neutralizing antibody seems to inhibit satellite cell migration.
The data reported here suggest for the first time that ANXA1 has a role in skeletal muscle differentiation as it does in other tissues and models. Thus modulating the migration of satellite cells, ANXA1 may contribute to the regeneration of skeletal muscle tissue.