RESUMO

The aim of this study was to evaluate the resorption process during the repair of autogenous bone grafts with or without coverage by an expanded polytetrafluoroethylene (e-PTFE) membrane in female rats with estrogen deficiency using the immunohistochemical technique. Eighty female rats were randomly divided into two groups (OVX and SHAM). The 40 female rats in the OVX group were subjected to ovariectomy, and the 40 female rats in the SHAM group were subjected to simulated ovariectomy. The two groups were further divided in subgroup E, which was subjected to surgery for placement of autogenous bone graft (ABG), and subgroup ME, in which the ABG was covered with an e-PTFE membrane. The animals were killed at 0, 7, 21, 45 and 60 days. The specimens were analyzed using immunohistochemistry for the bone resorption markers RANK, RANK-L and Osteoprotegerin (OPG). A higher remodeling rate was observed at 7 and 21 days after the autogenous bone grafts, when the markers were more intensely expressed. At the final time point, the specimens presented similar characteristics to those observed at the initial time point. The expression of immunohistochemical markers was not altered by the estrogen deficiency. The presence of the e-PTFE membrane delayed the bone resorption process, influencing the immunohistochemical expression of markers.

Assuntos

Regeneração Óssea/fisiologia , Transplante Ósseo , Estrogênios/deficiência , Osteoprotegerina/fisiologia , Ligante RANK/fisiologia , Receptor Ativador de Fator Nuclear kappa-B/fisiologia , Animais , Biomarcadores/metabolismo , Reabsorção Óssea/fisiopatologia , Feminino , Imuno-Histoquímica , Osteoclastos/fisiologia , Ovariectomia , Distribuição Aleatória , Ratos Wistar , Fatores de Tempo , Transplante Autólogo

RESUMO

OBJECTIVE: Leukocyte-associated immunoglobulin-like receptor-1 is an inhibitory receptor primarily expressed by immune cells. This study was undertaken to define the role of this molecule in osteoclast differentiation and rheumatoid arthritis. METHODS: In vitro osteoclast assays were performed to characterize the role of Leukocyte-associated immunoglobulin-like receptor-1 in murine and human osteoclastogenesis. Human Leukocyte-associated immunoglobulin-like receptor-1 expression was assessed by immunohistochemistry staining in the synovium of patients with rheumatoid arthritis. The levels of soluble Human Leukocyte-associated immunoglobulin-like receptor-1 were determined by enzyme-linked immunosorbent assay. RESULTS: We found that multinucleated osteoclast formation from mouse bone marrow cells was inhibited by treatment with a monoclonal antibody against mouse Leukocyte-associated immunoglobulin-like receptor-1 in vitro. By immunohistochemistry, we found that Leukocyte-associated immunoglobulin-like receptor-1 was mainly expressed by macrophages in the inflamed synovial tissue of rheumatoid arthritis patients. In addition, serum and synovial fluid levels of soluble Leukocyte-associated immunoglobulin-like receptor-1 were higher in rheumatoid arthritis patients compared to healthy controls or osteoarthritis patients. Moreover, overexpression of Leukocyte-associated immunoglobulin-like receptor-1 in CD14+ monocytes from healthy volunteers also inhibited human osteoclastogenesis. CONCLUSION: Collectively, these data demonstrate for the first time that Leukocyte-associated immunoglobulin-like receptor-1 inhibits osteoclastogenesis. Therefore, these results may have therapeutic implications for the treatment of rheumatoid arthritis.

Assuntos

Artrite Reumatoide/metabolismo , Osteoclastos/citologia , Receptores Imunológicos/fisiologia , Adulto , Idoso , Animais , Artrite Reumatoide/imunologia , Artrite Reumatoide/patologia , Células da Medula Óssea/patologia , Diferenciação Celular/fisiologia , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Receptores de Lipopolissacarídeos/sangue , Masculino , Camundongos , Pessoa de Meia-Idade , Osteoclastos/efeitos dos fármacos , Osteoprotegerina/fisiologia , Ligante RANK/sangue , Receptores Imunológicos/análise , Receptores Imunológicos/antagonistas & inibidores , Membrana Sinovial/metabolismo

RESUMO

OBJECTIVE: Leukocyte-associated immunoglobulin-like receptor-1 is an inhibitory receptor primarily expressed by immune cells. This study was undertaken to define the role of this molecule in osteoclast differentiation and rheumatoid arthritis. METHODS: In vitro osteoclast assays were performed to characterize the role of Leukocyte-associated immunoglobulin-like receptor-1 in murine and human osteoclastogenesis. Human Leukocyte-associated immunoglobulin-like receptor-1 expression was assessed by immunohistochemistry staining in the synovium of patients with rheumatoid arthritis. The levels of soluble Human Leukocyte-associated immunoglobulin-like receptor-1 were determined by enzyme-linked immunosorbent assay. RESULTS: We found that multinucleated osteoclast formation from mouse bone marrow cells was inhibited by treatment with a monoclonal antibody against mouse Leukocyte-associated immunoglobulin-like receptor-1 in vitro. By immunohistochemistry, we found that Leukocyte-associated immunoglobulin-like receptor-1 was mainly expressed by macrophages in the inflamed synovial tissue of rheumatoid arthritis patients. In addition, serum and synovial fluid levels of soluble Leukocyte-associated immunoglobulin-like receptor-1 were higher in rheumatoid arthritis patients compared to healthy controls or osteoarthritis patients. Moreover, overexpression of Leukocyte-associated immunoglobulin-like receptor-1 in CD14+ monocytes from healthy volunteers also inhibited human osteoclastogenesis. CONCLUSION: Collectively, these data demonstrate for the first time that Leukocyte-associated immunoglobulin-like receptor-1 inhibits osteoclastogenesis. Therefore, these results may have therapeutic implications for the treatment of rheumatoid arthritis. .

Assuntos

Adulto , Idoso , Animais , Feminino , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Artrite Reumatoide/metabolismo , Osteoclastos/citologia , Receptores Imunológicos/fisiologia , /sangue , Artrite Reumatoide/imunologia , Artrite Reumatoide/patologia , Células da Medula Óssea/patologia , Diferenciação Celular/fisiologia , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Imuno-Histoquímica , Osteoclastos/efeitos dos fármacos , Osteoprotegerina/fisiologia , Ligante RANK/sangue , Receptores Imunológicos/análise , Receptores Imunológicos/antagonistas & inibidores , Membrana Sinovial/metabolismo

RESUMO

OBJECTIVES: Little information is available on the molecular events that occur during graft incorporation over time. The calvarial bone (Cb) grafts have been reported to produce greater responses compared with other donor regions in maxillofacial reconstructions, but the scientific evidences for this are still lacking. The objectives of this study are (1) to study the morphological pattern of Cb onlay bone grafts and compare them with the biological events through immunohistochemical responses and (2) to establish the effects of perforations in maintaining the volume and bone density of the receptor bed. MATERIAL AND METHODS: Sixty New Zealand White rabbits were submitted to Cb onlay bone grafts on the mandible. In 30 rabbits, the receptor bed was perforated (perforated group), while for the remaining animals the bed was kept intact (non-perforated group). Six animals from each group were sacrificed at 5, 7, 10, 20 and 60 days after surgery. Histological sections from the grafted area were prepared for immunohistochemical and histological analyses. Immuno-labeling was found for proteins Osteoprotegerin (OPG), receptor activator of nuclear factor-kappabeta ligand (RANKL), alkaline phosphatase (ALP), osteopontin (OPN), vascular endothelial growth factor (VEGF), tartrate-resistant acid phosphatase (TRAP), Type I collagen (COL I) and osteocalcin (OC). The tomography examination [computerized tomography (CT) scan] was conducted just after surgery and at the sacrifice. RESULTS: The histological findings revealed that the perforations contributed to higher bone deposition during the initial stages at the graft-receptor bed interface, accelerating the graft incorporation process. The results of the CT scan showed lower resorption for the perforated group (P

Assuntos

Transplante Ósseo/fisiologia , Sobrevivência de Enxerto/fisiologia , Osseointegração/fisiologia , Osteogênese/fisiologia , Crânio/cirurgia , Fosfatase Ácida/fisiologia , Fosfatase Alcalina/fisiologia , Animais , Reabsorção Óssea/metabolismo , Transplante Ósseo/métodos , Colágeno Tipo I/fisiologia , Imuno-Histoquímica , Isoenzimas/fisiologia , Masculino , Osteocalcina/fisiologia , Osteopontina/fisiologia , Osteoprotegerina/fisiologia , Ligante RANK/fisiologia , Coelhos , Estatísticas não Paramétricas , Fosfatase Ácida Resistente a Tartarato , Tomografia Computadorizada por Raios X , Fator A de Crescimento do Endotélio Vascular/fisiologia