ABSTRACT
Melanoma inhibitory activity (MIA), also referred to as cartilage-derived retinoic acid-sensitive protein (CD-RAP), an 11-kDa secreted protein, is mainly expressed in cartilaginous tissue during embryogenesis and adulthood. Currently, the function of MIA in cartilage tissue is not understood. Here, we describe that MIA acts as a chemotactic factor on the mesenchymal stem cell line C3H10T1/2, stimulating cell migration significantly at concentrations from 0.24 to 240 ng/ml, while inhibiting cell migration at higher doses of 2.4 microg/ml. When analyzing the role of MIA during differentiation processes, we show that MIA by itself is not capable to induce the differentiation of murine or human mesenchymal stem cells. However, MIA influences the action of bone morphogenetic protein (BMP)-2 and transforming growth factor (TGF)-beta 3 during mesenchymal stem cell differentiation, supporting the chondrogenic phenotype while inhibiting osteogenic differentiation. Quantitative RT-PCR analysis revealed the up-regulation of the cartilage markers MIA, collagen type II and aggrecan in human mesenchymal stem cell (HMSC) cultures differentiated in the presence of MIA and TGF-beta 3 or BMP-2 when compared to HMSC cultures differentiated in the presence of TGF-beta 3 or BMP-2 alone. Further, MIA down-regulates gene expression of osteopontin and osteocalcin in BMP-2 treated HMSC cultures inhibiting the osteogenic potential of BMP-2. In the case of human primary chondrocytes MIA stimulates extracellular matrix deposition, increasing the glycosaminoglycan content. Therefore, we postulate that MIA is an important regulator during chondrogenic differentiation and maintenance of cartilage.
Subject(s)
Cell Differentiation , Chondrocytes/cytology , Mesenchymal Stem Cells/cytology , Neoplasm Proteins/physiology , Adult , Aggrecans , Animals , Bone Morphogenetic Protein 2 , Bone Morphogenetic Proteins/metabolism , Cartilage/cytology , Cartilage/metabolism , Cell Movement , Cells, Cultured , Chemotaxis , Chondrocytes/metabolism , Chondrogenesis , Collagen Type II/metabolism , Extracellular Matrix/metabolism , Extracellular Matrix Proteins/metabolism , Female , Gene Expression Regulation , Glycosaminoglycans/metabolism , Humans , Lectins, C-Type/metabolism , Male , Mesenchymal Stem Cells/metabolism , Mice , Middle Aged , Neoplasm Proteins/genetics , Osteocalcin/metabolism , Osteogenesis , Osteopontin , Proteoglycans/metabolism , RNA, Messenger/metabolism , Recombinant Proteins/genetics , Recombinant Proteins/isolation & purification , Recombinant Proteins/metabolism , Sialoglycoproteins/metabolism , Transforming Growth Factor beta/metabolism , Transforming Growth Factor beta3Subject(s)
Cell Culture Techniques/methods , Culture Media/chemistry , Stem Cells/cytology , Animals , Embryo, Mammalian , MiceABSTRACT
Knotted (Kn) genes are expressed within restricted domains of the plant meristems and play a key role in the control of plant morphogenesis. We have isolated the Kn-related gene Meis2 in mouse, which labels the lateral somitic compartment and its derivatives during early mouse embryogenesis and later becomes a marker for the dorso-ectodermal region overlying cells of the paraxial mesoderm. Meis2 is also highly expressed in specific areas of the developing central nervous system from embryonic day 9 (e9) onward. In later developmental stages, a strong expression is detectable in differentiating nuclei and regions of the forebrain, midbrain, hindbrain, and spinal cord. This temporal and spatial expression pattern suggests that Meis2 may play an important role in the cascade of induction leading to somitic differentiation as well as in brain regionalization and histogenesis.
Subject(s)
Arabidopsis Proteins , Gene Expression Regulation, Developmental , Homeodomain Proteins/genetics , Prosencephalon/embryology , Somites/metabolism , Amino Acid Sequence , Animals , Branchial Region/embryology , Cell Differentiation , Central Nervous System/embryology , Female , In Situ Hybridization , Male , Membrane Proteins/genetics , Mice , Molecular Sequence Data , Plant Proteins/genetics , Qa-SNARE Proteins , Sequence AlignmentABSTRACT
Mice lacking TGF-beta 3 exhibit an incompletely penetrant failure of the palatal shelves to fuse leading to cleft palate. The defect appears to result from impaired adhesion of the apposing medial edge epithelia of the palatal shelves and subsequent elimination of the mid-line epithelial seam. No craniofacial abnormalities were observed. This result demonstrates that TGF-beta 3 affects palatal shelf fusion by an intrinsic, primary mechanism rather than by effects secondary to craniofacial defects.
Subject(s)
Cleft Palate/genetics , Homeodomain Proteins , Palate/embryology , Repressor Proteins , Transcription Factors , Transforming Growth Factor beta/physiology , Animals , Base Sequence , Cleft Palate/embryology , Cytoskeletal Proteins/analysis , DNA-Binding Proteins/analysis , Extracellular Matrix Proteins/analysis , Goosecoid Protein , Mesoderm , Mice , Mice, Inbred C57BL , Mice, Knockout , Molecular Sequence Data , Morphogenesis , Palate/chemistry , Transforming Growth Factor beta/analysisABSTRACT
Transforming growth factor-beta 1 (TGF-beta 1) is a multifunctional growth factor that has profound regulatory effects on many developmental and physiological processes. Disruption of the TGF-beta 1 gene by homologous recombination in murine embryonic stem cells enables mice to be generated that carry the disrupted allele. Animals homozygous for the mutated TGF-beta 1 allele show no gross developmental abnormalities, but about 20 days after birth they succumb to a wasting syndrome accompanied by a multifocal, mixed inflammatory cell response and tissue necrosis, leading to organ failure and death. TGF-beta 1-deficient mice may be valuable models for human immune and inflammatory disorders, including autoimmune diseases, transplant rejection and graft versus host reactions.
