RESUMO
RT-PCR was used to analyze the expression of a series of mRNAs coding for proteoglycans aggrecan, versican, biglycan, decorin, fibromodulin and also hyaluronan synthase 1 in specimens obtained during discectomy of the temporomandibular joint in patients with unilateral signs and symptoms of chronic closed lock (eight patients) and painful clicking (seven patients). Regarding the disc, aggrecan expression was higher in patients with chronic closed lock. As for the posterior disc attachment specimens, patients with chronic closed lock showed a tendency for higher expression of biglycan and hyaluronan synthase 1. The degradation of matrix in patients with chronic closed lock of the temporomandibular joint seems not to be caused by a reduced synthesis and the degenerative process seen in these patients is one with low turnover similar to the situation in primary osteoarthrosis of hyaline cartilage. The results indicate that any treatment should intervene early in the disease process of chronic closed lock in order to prevent the development of a degenerative process.
Assuntos
Proteoglicanas/biossíntese , Disco da Articulação Temporomandibular/metabolismo , Transtornos da Articulação Temporomandibular/metabolismo , Adulto , Agrecanas , Análise de Variância , Biglicano , Proteoglicanas de Sulfatos de Condroitina/biossíntese , Doença Crônica , Decorina , Proteínas da Matriz Extracelular/biossíntese , Feminino , Fibromodulina , Glucuronosiltransferase/biossíntese , Humanos , Hialuronan Sintases , Lectinas Tipo C , Masculino , Pessoa de Meia-Idade , Osteoartrite/metabolismo , RNA Mensageiro/biossíntese , Disco da Articulação Temporomandibular/cirurgia , VersicanasRESUMO
The aim was to investigate the content of 4- and 6-sulphated glycosaminoglycans (GAGs) in specimens from temporomandibular joint disc and posterior disc attachment in patients with painful clicking and chronic closed lock. Nineteen patients (19 joints) with a clinical diagnosis of painful clicking were compared with 22 patients (22 joints) with a clinical diagnosis of chronic closed lock. Specimens were obtained from the disc and the posterior disc attachment, and their content of glycosaminoglycans analysed by means of capillary zone electrophoresis. These were significant differences in the amount of glycosaminoglycans between the two groups, values in patients with painful clicking being comparable to those of normal individuals, while patients having chronic closed lock showed significantly reduced values. Both groups showed higher values in the posterior disc attachment when compared to the disc and similar pattern of glycosaminoglycan sulphation. The results suggest that these two patient groups have distinctly different patterns of tissue reactions. In patients with chronic closed lock there was an altered composition of matrix, this change involving both disc and posterior disc attachment.