Immunostaining of skeletal tissues.

Immunohistochemistry (IHC) is a routinely used technique in clinical diagnosis of pathological conditions and in basic research. It combines anatomical, immunological, and biochemical methods and relies on the specific binding of an antibody to an antigen. Using the technique with mineralised tissues is more complicated than with soft tissues.

Functional mesenchymal stem cell niches in adult mouse knee joint synovium in vivo.

Objective: We previously reported that human synovium contains cells that, after culture expansion, display properties of mesenchymal stem cells (MSCs). The objective of this study was to identify MSCs in native synovium in vivo.

Methods: To identify stem cells in the synovium in vivo, a double nucleoside analog cell-labeling scheme was used in a mouse model of joint-surface injury.

Mesenchymal stem cells: a perspective from in vitro cultures to in vivo migration and niches.

Mesenchymal Stromal Progenitor/Stem Cells (MSCs) are a rare population of non-hematopoietic stromal cells, present in the bone marrow and most connective tissues of the body. They are capable of differentiation into mesenchymal tissues such as bone, cartilage, adipose tissue and muscle. In the absence of specific markers, MSCs have been defined following isolation and culture expansion, by their expression of various molecules including CD90, CD105 and CD73 and absence of markers like CD34, CD45, and CD14.

Mesenchymal stem cells from development to postnatal joint homeostasis, aging, and disease.

Joint morphogenesis involves signaling pathways and growth factors that recur in the adult life with less redundancy to safeguard joint homeostasis. Loss of such homeostasis due to abnormal signaling networks as in aging could lead to diseases such as osteoarthritis. Stem cells are the cellular counterpart and targets of the morphogenetic signals, and they function to maintain the tissues by ensuring replacement of cells lost to physiological turnover, injury, aging, and disease.

Yap is a novel regulator of C2C12 myogenesis.

The expression, regulation and function of mammalian Hippo pathway members in skeletal muscle is largely unknown. The aim of this study was thus to test the hypothesis that core members of the mammalian Hippo pathway are expressed in skeletal muscle and that the transcriptional co-factor Yap, a core member of the Hippo pathway, regulates C2C12 myogenesis. We found that the major components of the mammalian Hippo pathway including Yap are all expressed in skeletal muscles, C2C12 myoblasts and myotubes.

Distinct mesenchymal progenitor cell subsets in the adult human synovium.

Objective: To analyse the heterogeneity at the single-cell level of human mesenchymal progenitor cells from SM.

Methods: Cell populations were enzymatically released from the knee joint synovium of adult human individuals. Single cell-derived clonal populations were obtained by limiting dilution and serially passaged to determine growth rates.