RESUMO
The gp130 receptor and its binding partners play a central role in cytokine signalling. Ciliary neurotrophic factor (CNTF) is one of the cytokines that signals through the gp130 receptor complex. CNTF has previously been shown to be a negative regulator of trabecular bone remodelling and important for motor neuron development. Since haematopoietic cell maintenance and differentiation is dependent on the bone marrow (BM) microenvironment, where cells of the osteoblastic lineage are important regulators, we hypothesised that CNTF may also have important roles in regulating haematopoiesis. Analysis of haematopoietic parameters in male and female Cntf(-/-) mice at 12 and 24 weeks of age revealed altered B lymphopoiesis. Strikingly, the B lymphocyte phenotype differed based on sex, age and also the BM microenvironment in which the B cells develop. When BM cells from wildtype mice were transplanted into Cntf(-/-) mice, there were minimal effects on B lymphopoiesis or bone parameters. However, when Cntf(-/-) BM cells were transplanted into a wildtype BM microenvironment, there were changes in both haematopoiesis and bone parameters. Our data reveal that haematopoietic cell-derived CNTF has roles in regulating BM B cell lymphopoiesis and both trabecular and cortical bone, the latter in a sex-dependent manner.
Assuntos
Linfócitos B/metabolismo , Diferenciação Celular/genética , Fator Neurotrófico Ciliar/genética , Hematopoese/genética , Animais , Linfócitos B/citologia , Células da Medula Óssea/metabolismo , Remodelação Óssea/genética , Microambiente Celular/genética , Fator Neurotrófico Ciliar/metabolismo , Receptor gp130 de Citocina/genética , Receptor gp130 de Citocina/metabolismo , Feminino , Ativação Linfocitária/genética , Masculino , Camundongos , Camundongos Transgênicos , Transdução de Sinais/genéticaRESUMO
Information about the development and function of human macrophage lineage populations, such as osteoclasts, is limited because of the lack of defined in vitro systems for their large-scale generation. Two M-CSF-containing cytokine cocktails were found under serum-free conditions to expand dramatically and to differentiate over time human CD34(+) hemopoietic stem cells into nonadherent and adherent macrophage populations. These populations exhibited increasing degrees of maturity over a 3-week period characterized by morphology, surface marker expression (CD11b, CD86, CD64, CD14, and c-Fms), phagocytic function, and gene-expression profiling using quantitative PCR and microarray analysis (principal component analysis, k-means clustering, and gene ontology classification). As assessed by the last criterion, the adherent population obtained at 3 weeks from the one protocol tested had high similarity to the well-studied peripheral blood monocyte-derived macrophages. The one population tested could be induced to differentiate into osteoclasts in the presence of M-CSF and receptor activator of NF-kappaB ligand, as judged by morphology, gene expression, and bone-resorbing ability. In addition to the large numbers of macrophage lineage cells able to be produced, this replicating system may be suitable for the molecular analysis of macrophage lineage commitment and progression and for gene targeting and delivery.
