RESUMO
Recombinant human (rh) bone morphogenetic protein 12 (BMP12) is proved to induce the formation of tendon and ligament tissues in animal experiments. But the roles of BMP12 on tissue regeneration in human tendons remain unexplored. In the present study, healthy human patellar tendon samples were collected for histological examination and preparation of tendon fibroblast culture. Immunohistochemical staining showed that BMP12 was detected on healthy patellar tendon samples, only located on active tenoblasts and perivascular mesenchymal cells but not in interstitial tenocytes. The expression of PCNA and procollagen type I also exhibited a similar distribution. It indicates that BMP12 may be involved in matrix remodeling process in adult tissues. In vitro studies showed that rhBMP12 could increase proliferation of tendon fibroblasts and increase the gene expression of procollagen type I and type III, but decrease the gene expression of decorin in tendon fibroblasts culture. Our findings suggest that BMP12 may play a role in early phases of tissue regeneration in tendons.
Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Divisão Celular/fisiologia , Matriz Extracelular/metabolismo , Fibroblastos/fisiologia , Ligamento Patelar/metabolismo , Fator de Crescimento Transformador beta , Adolescente , Adulto , Biglicano , Proteínas Morfogenéticas Ósseas/genética , Células Cultivadas , Decorina , Proteínas da Matriz Extracelular , Feminino , Fibroblastos/citologia , Fatores de Diferenciação de Crescimento , Humanos , Masculino , Ligamento Patelar/citologia , Pró-Colágeno/genética , Pró-Colágeno/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , Proteoglicanas/genética , Proteoglicanas/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMO
Patellar tendinosis is characterized by longstanding localized and activity-related pain, swelling and tenderness on palpation, and characteristic features on magnetic resonance imaging and ultrasonography and during surgical excision. Histologic examination of tendinosis tissues shows disrupted collagen matrix, increased cellularity, and increased proteoglycan stainability, but lack of inflammatory cell infiltration despite the clinical signs resembling inflammation. Disturbances in inflammatory response may be associated with the development of tendinosis. Expression of cyclooxygenase-2 and transforming growth factor-beta1 were detected in tendinosis, and the in vitro production of prostaglandin E2 by tendinosis and healthy tendon fibroblast cultures also was observed. Eleven patients with patellar tendinosis and 12 control subjects with healthy patellar tendons, but deficient anterior cruciate ligaments, were included in the current study. The percentages of immunopositive cells in tendinosis samples for cyclooxygenase-2 and transforming growth factor-beta1 were 66.75 and 56.40, respectively, which were significantly higher than those of the control subjects (25.15 and 23.06 respectively). Tendinosis fibroblast culture also produced more prostaglandin E2 and active transforming growth factor-beta1. These findings indicate the involvement of prostaglandins and cytokines that may explain the clinical symptoms and nonhealing features of tendinosis.
