RESUMEN
Our aims were to describe the distribution of alpha-smooth muscle actin (SMA)-containing cells in Dupuytren's tissue in vivo and to determine the effects of selected agents in regulating the expression of SMA in Dupuytren's cells in vitro. In selected hypercellular zones of Dupuytren's nodules up to 40% of the cells contained SMA, as shown by immunohistochemistry. A lower percentage (20%) of SMA-containing cells was found in regions of lower cellularity. A notable finding was that treatment in vitro of Dupuytren's cells with platelet-derived growth factor significantly reduced the content of SMA. Cells from the same patients showed a significant increase in expression of SMA in response to treatment with transforming growth factor, which confirmed recent findings. In addition, interferon-gamma, which has been previously used as a treatment for Dupuytren's disease in a clinical study, had no reproducible effect on the expression of this actin isoform. Our findings are of significance for the conservative management of contractures.
Asunto(s)
Actinas/metabolismo , Contractura de Dupuytren/metabolismo , Músculo Liso/metabolismo , Adulto , Anciano , Análisis de Varianza , Western Blotting , Femenino , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana EdadRESUMEN
The objective of the study was to investigate the behavior of porcine enamel, dentin, and cementum cells, isolated from tissue digests and growing out from explants, in monolayer culture and in a collagen-glycosaminoglycan (GAG) matrix for tissue engineering. A notable finding of the study was the expression of a contractile muscle actin isoform, alpha-smooth muscle actin (SMA), by each cell type and their contraction of the collagen-GAG scaffold. Of importance was the immunohistochemical demonstration that the majority of ameloblasts and odontoblasts in vivo contained SMA. Western blot analysis demonstrated the presence of SMA in all of the cell types. A large amount of SMA was found in the odontoblasts after the first passage. SMA expression in the enamel- and cementum-derived cells appeared to increase with time in culture and with passage number. The implications of this finding for tissue engineering and the possible roles for SMA in dental tissue cells are discussed.
Asunto(s)
Actinas/fisiología , Colágeno/fisiología , Glicosaminoglicanos/fisiología , Porcinos/fisiología , Ingeniería de Tejidos , Actinas/genética , Animales , Western Blotting , Técnicas de Cultivo de Célula , ADN/metabolismo , Cemento Dental/fisiología , Esmalte Dental/fisiología , Dentina/fisiología , Inmunohistoquímica , Mandíbula/fisiologíaRESUMEN
The finding of expression of a muscle actin isoform, alpha-smooth-muscle actin (SMA), by the stromal cells of several tissues prompted this study of SMA expression by cells derived from the porcine dental pulp. The SMA content of the cells increased with time in culture. These SMA-containing cells were found to have the capability to contract a collagen-glycosaminoglycan analog of extracellular matrix in vitro.
Asunto(s)
Actinas/análisis , Pulpa Dental/metabolismo , Matriz Extracelular/metabolismo , Actinas/genética , Actinas/fisiología , Análisis de Varianza , Animales , Anticuerpos Monoclonales , Western Blotting , Recuento de Células , Células Cultivadas , Sulfatos de Condroitina/química , Sulfatos de Condroitina/metabolismo , Colágeno Tipo I/química , Colágeno Tipo I/metabolismo , ADN/análisis , Pulpa Dental/citología , Liofilización , Regulación de la Expresión Génica , Inmunohistoquímica , Porosidad , Isoformas de Proteínas/análisis , Isoformas de Proteínas/genética , Isoformas de Proteínas/fisiología , Estadística como Asunto , Células del Estroma/metabolismo , Propiedades de Superficie , PorcinosRESUMEN
Lapine and canine marrow stromal cells were found to contain a contractile actin isoform, alpha-smooth muscle actin (SMA), by immunohistochemistry and Western blot analysis. The SMA was found to be incorporated into stress fibers that were prominently displayed by the cells in monolayer culture. The cell content of this actin isoform increased with passage number. The contractility of SMA-expressing stromal cells was demonstrated by their contraction of collagen-glycosaminoglycan analogs of extracellular matrix into which they were seeded. The demonstration that marrow-derived stromal cells express the SMA gene may explain recent findings of this expression in musculoskeletal connective tissue cells including osteoblasts, chondrocytes, and fibrochondrocytes that may be derived from this mesenchymal stem cell. The implications of these findings for tissue engineering strategies employing marrow stromal cells are also discussed.