RESUMO
Plastin 3 (PLS3), a protein involved in the formation of filamentous actin (F-actin) bundles, appears to be important in human bone health, on the basis of pathogenic variants in PLS3 in five families with X-linked osteoporosis and osteoporotic fractures that we report here. The bone-regulatory properties of PLS3 were supported by in vivo analyses in zebrafish. Furthermore, in an additional five families (described in less detail) referred for diagnosis or ruling out of osteogenesis imperfecta type I, a rare variant (rs140121121) in PLS3 was found. This variant was also associated with a risk of fracture among elderly heterozygous women that was two times as high as that among noncarriers, which indicates that genetic variation in PLS3 is a novel etiologic factor involved in common, multi-factorial osteoporosis.
Assuntos
Fraturas Ósseas/genética , Glicoproteínas de Membrana/genética , Proteínas dos Microfilamentos/genética , Osteoporose/genética , Adulto , Animais , Densidade Óssea/genética , Remodelação Óssea/genética , Criança , Pré-Escolar , Feminino , Fraturas Ósseas/etiologia , Doenças Genéticas Ligadas ao Cromossomo X/genética , Heterozigoto , Humanos , Masculino , Mutação , Osteoporose/complicações , Linhagem , Polimorfismo de Nucleotídeo Único , Fatores de Risco , Adulto Jovem , Peixe-ZebraRESUMO
To analyze the effect of intramedullary reaming on fracture healing, we investigated whether or not cortical reamings contain viable bone cells. There are several tissue components contained in medullary reamings including blood, bone marrow and cortical bone. This study is focused on the cortical reamings, which are produced during reaming of the medullary cavity. They may stimulate fracture healing but it is still unclear if they contain vital bone cells. We tested the hypothesis that these cortical reamings are a source of viable bone cells and compared cell cultures with cultivated cells from iliac crest biopsies. Responses of protein content and ALP activity to vitD stimulation in the cells were considered as properties of viability. Ten in tact living sheep femora were fully reamed and the cortical reamings were cultivated in a standard manner and compared with cultivated cells from ipsi-lateral iliac crest biopsies from the same animals. Cells started to grow from the reamings as well as the iliac crest within 2-5 days, and covered the entire culture flask within 9-13 days. Protein content and ALP activity in cells from both reamings and iliac crest were significantly responsive to vitD stimulation. Cortical reamings from intramedullary nailing have osteoblastic potential and contain living bone cells similar to bone cells from the iliac crest. These findings may further explain the superior healing of fractures, treated with reamed nailing.
Assuntos
Transplante Ósseo , Fraturas do Fêmur/cirurgia , Fêmur/citologia , Consolidação da Fratura/fisiologia , Osteoblastos/fisiologia , Fosfatase Alcalina/metabolismo , Animais , Pinos Ortopédicos , Divisão Celular/efeitos dos fármacos , Separação Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Feminino , Fêmur/fisiologia , Fêmur/cirurgia , Ílio/citologia , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Ovinos , Vitamina D/farmacologiaRESUMO
Osteocytes can be isolated from chicken calvaria using mild EDTA treatment alternating with collagenase treatment. The cell population obtained contains both osteoblasts and osteocytes. A pure population of osteocytes is obtained following immunomagnetic separation with the osteocyte-specific monoclonal antibody MAb OB7.3.