RESUMEN
Induced pluripotent stem cells (iPSCs) can differentiate into mineralizing cells and thus have a great potential in application in engineered bone substitutes with bioactive scaffolds in regeneration medicine. In the current study we characterized and demonstrated the pluripotency and osteogenic differentiation of mouse iPSCs. To enhance the osteogenic differentiation of iPSCs, we then transduced the iPSCs with the potent transcription factor, nuclear matrix protein SATB2. We observed that in SATB2-overexpressing iPSCs there were increased mineral nodule formation and elevated mRNA levels of key osteogenic genes, osterix (OSX), Runx2, bone sialoprotein (BSP) and osteocalcin (OCN). Moreover, the mRNA levels of HoxA2 was reduced after SATB2 overexpression in iPSCs. The SATB2-overexpressing iPSCs were then combined with silk scaffolds and transplanted into critical-size calvarial bone defects created in nude mice. Five weeks post-surgery, radiological and micro-CT analysis revealed enhanced new bone formation in calvarial defects in SATB2 group. Histological analysis also showed increased new bone formation and mineralization in the SATB2 group. In conclusion, the results demonstrate that SATB2 facilitates the differentiation of iPSCs towards osteoblast-lineage cells by repressing HoxA2 and augmenting the functions of the osteoblast determinants Runx2, BSP and OCN.
Asunto(s)
Regeneración Ósea/fisiología , Células Madre Pluripotentes Inducidas/fisiología , Proteínas de Unión a la Región de Fijación a la Matriz/metabolismo , Seda/química , Cráneo/patología , Ingeniería de Tejidos/instrumentación , Andamios del Tejido/química , Factores de Transcripción/metabolismo , Animales , Materiales Biocompatibles/química , Materiales Biocompatibles/metabolismo , Diferenciación Celular , Células Cultivadas , Subunidad alfa 1 del Factor de Unión al Sitio Principal/genética , Subunidad alfa 1 del Factor de Unión al Sitio Principal/metabolismo , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Células Madre Pluripotentes Inducidas/citología , Sialoproteína de Unión a Integrina/genética , Sialoproteína de Unión a Integrina/metabolismo , Ensayo de Materiales , Proteínas de Unión a la Región de Fijación a la Matriz/genética , Ratones , Ratones Desnudos , Osteocalcina/genética , Osteocalcina/metabolismo , Cráneo/citología , Cráneo/metabolismo , Factor de Transcripción Sp7 , Ingeniería de Tejidos/métodos , Factores de Transcripción/genética , Transducción Genética , Cicatrización de Heridas/fisiologíaRESUMEN
OBJECTIVE: To study the distribution and expression of fibromodulin, decorin and biglycan in developing normal periodontal tissues, so as to understand its role in periodontal tissue formation. METHODS: Thirty six BALB/c mice in different developing stages were killed and their bilateral mandibular first molars with surrounding alveolar bones and gingival tissues were taken out, Power Vision two steps immunohistochemical method with anti-fibromodulin, anti-decorin and anti-biglycan was used to detect the tissue distribution and cellular localization of fibromodulin and related proteoglycans, decorin and biglycan. RESULTS: Fibromodulin was strongly expressed in the subcutaneous gingival connective tissue, periodontal ligament, mainly in gingival and periodontal fibroblasts as well as their matrices. Strong expression was also noted in the area close to the interfaces of periodontal ligament-alveolar bone and periodontal ligament-cementum. Decorin was strongly expressed in the area of gingival connective tissue, periodontal ligament and the surface of alveolar bone, while biglycan was stained evidently in gingival connective tissue throughout the period of investigation, but negative in the surface of alveolar bone and osteoblasts. CONCLUSIONS: Fibromodulin may interact with decorin and biglycan to regulate the network formation of gingival connective tissues and periodontal collagen fibers, and may be involved in mineralization of the alveolar bone and cementum.
Asunto(s)
Proceso Alveolar/citología , Proteínas de la Matriz Extracelular/análisis , Encía/química , Osteoblastos/química , Ligamento Periodontal/química , Proteoglicanos/análisis , Proceso Alveolar/crecimiento & desarrollo , Animales , Biglicano , Decorina , Fibromodulina , Encía/crecimiento & desarrollo , Inmunohistoquímica , Ratones , Ratones Endogámicos BALB C , Ligamento Periodontal/crecimiento & desarrollo , Germen Dentario/químicaRESUMEN
PURPOSE: To study the distribution of dentin matrix protein 1, osteopontin and bone sialoprotein during cementum formation and cementoblasts differentiation in mouse. METHODS: Thirty six BALB/c postnatal mice were divided into four groups according to the developing stages, nine in each was subdivided into three parts randomly to examine the location of DMP1, OPN and BSP, a tooth developing study model was built and examined using histological methods correspondingly. PV two steps immunohistochemical assay was used to localize the distribution of the three regulatory factors timely and spatially. Repeated measures ANOVA and statistical analysis software of CMIAS were used to analyze the intensity of the dyed images. RESULTS: There was a series expression of the three regulatory proteins. DMP1 was expressed in the dental follicle cells in day 5 of postnatal stages and negatively expressed when the cell began to differentiate; meanwhile, since day 10 and on OPN was positively located in cementoblasts until the root developed completely; but BSP was expressed in the same cell in day 15 to 20, and then decreased to be negative. There were significant differences statistically among the three factors in each stage observed in the study except OPN between day 15 and 25. CONCLUSIONS: There are different locations timely and spatially among the three proteins, it hints that they play important different roles during the differentiation of cementoblasts and formation of cementum.