OBJECTIVETo study the feasibility of osteogenic phenotype expression by human skin fibroblasts induced in polyglycolic acid (PGA) foams and the effect of tumor necrosis factor-alpha (TNF-alpha) on the expression of bone morphogenetic protein (BMP) receptors.

METHODSThe fibroblasts were isolated, purified from human skin. (1) Fibroblasts were seeded onto PGA foams. The cell-PGA complexes were cultured in RCCS for 6 weeks, in the media of TNF-alpha (50 U/ml) and BMP-2 (0.1 microg/ml). 1 d, 3 and 6 weeks later, cells and extracellular matrix were investigated by electron microscopic and histochemistry observation respectively. Secretion of osteogenic markers were analyzed by biochemical methods. (2) Fibroblasts were seeded on the glass fragments or culture flasks and treated with TNF-alpha (50 U/ml) in different usage (one-time, all-time). The RT-PCR method and the immunohistochemistry fluorescence staining were used to examine the influence of TNF-alpha on the mRNA expression and the protein expression of the type I BMP receptors at 2, 4, 6, 8 d after treatment.

RESULTSFibroblasts seeded on the PGA foams formed 3-dimensional matrix 3 weeks after seeding, which was demonstrated as osteo-tissue by tetracycline labeling and ARS staining. Cells secreted much more bone-specific alkaline phosphatase (B-AKP) and osteocalcin (OCN) into supernatant than the cells that were cultured in the media without TNF-a and BMP2. Eight days after all-time usage, the TNF-alpha (50 U/ml) increased the expression of the mRNA and protein of the type IB BMP receptor.

CONCLUSIONSFibroblasts on 3-D cell-foam structures can express osteoblastic phenotype under certain inducing conditions. The numerous fibroblasts in body would be a promising resource for cell seeds candidate of tissue- engineered bone. TNF-alpha provides the essential condition for BMP2's target effect on fibroblasts, and combined use of TNF-alpha and BMP2 is one of the regulating factors.

Bone Morphogenetic Protein 2 ; Bone Morphogenetic Protein Receptors, Type I ; biosynthesis ; genetics ; Bone Morphogenetic Protein Receptors, Type II ; biosynthesis ; genetics ; Bone Morphogenetic Proteins ; pharmacology ; Cell Culture Techniques ; methods ; Cell Differentiation ; drug effects ; Cells, Cultured ; Drug Synergism ; Fibroblasts ; cytology ; drug effects ; metabolism ; Humans ; Phenotype ; Polyglycolic Acid ; Transforming Growth Factor beta ; pharmacology ; Tumor Necrosis Factor-alpha ; pharmacology

OBJECTIVETo observe the expression pattern of bone morphogenetic protein receptor IA (BMPR IA) in rats after contusive spinal cord injury.

METHODSThe expressions of BMPR IA, IB, and II were detected by immunochemistry in the spinal cord of normal adult rats, and the expression of BMPR IA was detected in the infinite horizons impactor model at 1, 3, 7, 14, 30, and 60 days after spinal cord injury.

RESULTSIn the spinal cord of normal adult rats, BMPR IA and II were expressed predominantly in the oligodentrocytes and neurons in the grey matter, and also in some astrocytes and numerous microglia cells. Only a low level of BMPR IB expression was detected in the neurons of the grey matter. After spinal cord injury, the expression of BMP IA markedly increased with sustained strong expression in the astrocytes till one month after the injury; its expression was also increased obviously in the microglia cells activated by the injury.

CONCLUSIONThe expression of BMPR IA increases significantly in the astrocytes and activated microglia cells in rats after contusive spinal cord injury, suggesting the involvement of BMP signaling pathway in the physiological and pathological role of glia cells.

Animals ; Astrocytes ; metabolism ; Bone Morphogenetic Protein Receptors, Type I ; metabolism ; Female ; Microglia ; metabolism ; Rats ; Rats, Sprague-Dawley ; Spinal Cord Injuries ; metabolism

OBJECTIVETo investigate the probabilities of core-biding factor a1 (Cbfa1) expression by human skin fibroblasts induced in vitro.

METHODSThe fibroblasts were isolated, purified from human skin, and were grown in incubation in the media of TNF-alpha, BMP-2, and combined TNF-alpha and BMP-2 at certain concentrations, respectively. The changes in biological features of these fibroblasts correlated with osteogenesis were detected by immunohistochemistry and RT-PCR assay.

RESULTSTNF-alpha could switch phenotype of collagen in fibroblasts from Type I and III to Type I and induce fibroblasts to express Ras and BMP type I receptor (BMPR-IA). TNF-alpha in combination with BMP-2 could induce fibroblasts to express Cbfa1 and osteocalcin mRNA.

CONCLUSIONHuman skin fibroblast could be induced into pro-osteoblast expressing Cbfa1, an osteoblast-specific transcription factor and a regulation of osteoblast differentiation, and combined use of TNF-alpha and BMP-2 was one of the regulating factors.

Bone Morphogenetic Protein 2 ; Bone Morphogenetic Protein Receptors, Type I ; Bone Morphogenetic Proteins ; pharmacology ; Cells, Cultured ; Collagen ; biosynthesis ; Core Binding Factor Alpha 1 Subunit ; Core Binding Factors ; Fibroblasts ; metabolism ; Humans ; Neoplasm Proteins ; Osteocalcin ; biosynthesis ; Protein-Serine-Threonine Kinases ; biosynthesis ; RNA, Messenger ; analysis ; Receptors, Growth Factor ; biosynthesis ; Skin ; cytology ; Transcription Factors ; biosynthesis ; genetics ; Transforming Growth Factor beta ; Tumor Necrosis Factor-alpha ; pharmacology

Adenomatous Polyposis Coli ; genetics ; metabolism ; pathology ; Bone Morphogenetic Protein Receptors, Type I ; genetics ; metabolism ; Colorectal Neoplasms, Hereditary Nonpolyposis ; genetics ; metabolism ; pathology ; Genes, APC ; Genetic Predisposition to Disease ; Hamartoma Syndrome, Multiple ; genetics ; metabolism ; pathology ; Humans ; Microsatellite Instability ; Mutation ; PTEN Phosphohydrolase ; genetics ; metabolism ; Peutz-Jeghers Syndrome ; genetics ; metabolism ; pathology ; Protein-Serine-Threonine Kinases ; genetics ; metabolism ; Proto-Oncogene Proteins B-raf ; genetics ; metabolism

To investigate the function of ALK3 gene, the gene regulation and the signaling pathway related to ventricular septum defect during heart development. The model mice with ALK3 gene knock-out via alpha-MHC-Cre/lox P system were bred. The mRNA expression level of control group was compared with that of experiment group and ALK3 downstream genes were screened using PCR-select cDNA subtraction microarray. The mRNA of control group was extracted from E11.5 normal mouse hearts, and that of experiment group, from E11.5 hearts of mice with alpha-MHC Cre(+/-) ALK3(F/+) genotype. It was found that the mice with ALK3 gene knock-out produced heart defects involving the interventricular septum. The platelet-activating factors acetylhydrolase and the transcription factor Pax-8 and so on, were down-regulated. However, the Protein Tyrosine Kinase (PTK) of Focal Adhesion Kinase (FAK) subfamily and beta subtype protein 14-3-3 were up-regulated in the alpha-MHC Cre(+/-) ALK3(F/-) mice. These data provide support that ALK3 gene played an important role during heart development. The platelet-activating factors acetylhydrolase and Pax-8 genes could be important ALK3 downstream genes in the BMP signaling pathway during interventricular septum development. PTK and beta subtype protein 14-3-3 might be regulatory factors in this pathway.
1-Alkyl-2-acetylglycerophosphocholine Esterase ; genetics ; metabolism ; 14-3-3 Proteins ; genetics ; metabolism ; Animals ; Bone Morphogenetic Protein Receptors, Type I ; genetics ; metabolism ; Genotype ; Heart Septal Defects, Ventricular ; genetics ; Mice ; Mice, Knockout ; Oligonucleotide Array Sequence Analysis ; PAX8 Transcription Factor ; Paired Box Transcription Factors ; genetics ; metabolism ; Protein-Tyrosine Kinases ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Signal Transduction ; genetics ; physiology