RESUMO
The cytoskeleton mediates various cellular processes such as differentiation and fusion, including in the filopodia and podosomes. However, apart from cell migration and formation of the sealing zone, little is known regarding the changes and related regulatory mechanisms of the cytoskeleton and additional roles of the filopodia and podosomes during the differentiation and fusion of osteoclasts. The cytomorphology and cytoskeleton of osteoclasts in the differentiation process were evaluated using tartrate-resistant acid phosphatase staining and immunofluorescence staining. Moreover, the expression levels of Rho GTPases and enzymes related to osteoclast differentiation and bone resorption were detected by quantitative reverse transcription-polymerase chain reaction. We detected 3 types of filopodia in osteoclast precursors and only 1 type of filopodia in undifferentiated cells. Mature osteoclasts were completely devoid of filopodia. Interestingly, cell fusion was highly specific, and the fusion initially occurred to the filopodia. Confocal images revealed that F-actin and microtubules significantly differed among fused cells. These results suggest that filopodia and podosomes not only play important roles in cell migration and the formation of sealing zones but also in the pre-fusion selectivity of 2 cells and the movement direction of the cell nucleus and cytoplasm during the fusion process. In addition, cdc42v1, RhoU, and RhoF regulate the formation of 3 types of filopodia during various stages of differentiation, while Rac1, Rac2, and filament A may be associated with cell selectivity during the fusion process.
Assuntos
Citoesqueleto de Actina/metabolismo , Osteoclastos/metabolismo , Pseudópodes/metabolismo , Fosfatase Ácida/genética , Fosfatase Ácida/metabolismo , Citoesqueleto de Actina/ultraestrutura , Actinas/genética , Actinas/metabolismo , Animais , Catepsina K/genética , Catepsina K/metabolismo , Adesão Celular , Diferenciação Celular , Fusão Celular , Linhagem Celular , Movimento Celular , Núcleo Celular/metabolismo , Núcleo Celular/ultraestrutura , Citoplasma/metabolismo , Citoplasma/ultraestrutura , Filaminas/genética , Filaminas/metabolismo , Expressão Gênica , Perfilação da Expressão Gênica , Isoenzimas/genética , Isoenzimas/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Microtúbulos/metabolismo , Microtúbulos/ultraestrutura , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Osteoclastos/ultraestrutura , Pseudópodes/ultraestrutura , Fosfatase Ácida Resistente a Tartarato , Tubulina (Proteína)/genética , Tubulina (Proteína)/metabolismo , Proteínas rho de Ligação ao GTP/genética , Proteínas rho de Ligação ao GTP/metabolismoRESUMO
OBJECTIVE: To investigate risk factors, stroke pattern and outcome in stroke patients with cancer. METHODS: A retrospective review of all stroke patients with cancer (n = 69) admitted to Bankstown-Lidcombe Hospital, Sydney, Australia, between January 1999 and December 2004 was conducted, and comparison made to age- and gender-matched non-cancer stroke patients admitted to the same hospital during the same period. RESULTS: Vascular risk factors did not significantly differ between cancer and non-cancer groups. There was a trend towards greater risk of intracerebral haemorrhage in the cancer group vs the non-cancer group. Previous deep vein thrombosis was more common, and prothrombin time and activated partial thromboplastin time were prolonged in the cancer group vs the non-cancer group. More patients died in hospital in the cancer group vs the non-cancer group. CONCLUSIONS: Coagulation disorders are more likely to be seen in stroke patients with cancer, and patients with cancer have a higher in-hospital post-stroke mortality.
