RESUMO
BACKGROUNDS: Matrix stiffness has been found to regulate cell morphology, while both cell morphology and matrix stiffness are verified as important factors directing BMSCs (bone marrow mesenchymal stem cells) differentiation. This study aimed to investigate whether matrix stiffness depended on cell morphology to regulate osteogenesis and adipogenesis of BMSCs on 2D substrates. METHODS AND RESULTS: First, we seeded BMSCs on tissue culture plates (TCPs) with different fibronectin (FN) concentrations and cytoskeleton inhibitor cytochalasin D, and FN was found to promote cell spreading and osteogenesis while inhibiting adipogenesis of BMSCs through F-actin reorganization. Based on these, we modulated BMSCs morphology on 0.5 kPa and 32 kPa CytoSoft® substrates through FN. High concentration of FN (300 µg/ml) coated on 0.5 kPa substrates promoted cell spreading to similar levels with 32 kPa substrates coated with 100 µg/ml of FN, and cells in both groups dominantly commit osteogenesis. On the other hand, low FN concentration (30 µg/ml) on 32 kPa substrates induced restricted cell morphology similar with 0.5 kPa substrates coated with 100 µg/ml of FN, and cells in both groups mainly commit adipogenesis. Immunofluorescence indicated nuclear translocation and higher intensity of YAP/TAZ when cells spread to larger areas, regardless of matrix stiffness. However, when cell spreading areas were fixed as similar levels, matrix stiffness didn't significantly affect YAP/TAZ intensity or location. CONCLUSIONS: Matrix stiffness failed to regulate BMSCs differentiation and YAP/TAZ activity without corresponding cell morphology. Cell spreading area could mediate effects of matrix stiffness on osteogenesis and adipogenesis of BMSCs.
Assuntos
Células-Tronco Mesenquimais , Osteogênese , Adipogenia , Diferenciação Celular , Células CultivadasAssuntos
Autofagia/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Proteínas de Ligação a RNA/efeitos dos fármacos , Proteína Sequestossoma-1/efeitos dos fármacos , Ácido Silícico/química , Adenina/análogos & derivados , Adenina/química , Fosfatase Alcalina/metabolismo , Animais , Antígenos Glicosídicos Associados a Tumores/metabolismo , Densidade Óssea/efeitos dos fármacos , Calcificação Fisiológica/efeitos dos fármacos , Linhagem Celular , Colágeno/química , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Feminino , Glicoproteínas/metabolismo , Humanos , Camundongos , Proteínas Associadas aos Microtúbulos/metabolismo , Modelos Animais , Osteoblastos/citologia , Osteogênese , Proteínas de Ligação a RNA/genética , Ratos Wistar , Proteína Sequestossoma-1/genéticaRESUMO
Bone tissue is remodeled through the catabolic function of the osteoclasts and the anabolic function of the osteoblasts. The process of bone homeostasis and metabolism has been identified to be co-ordinated with several local and systemic factors, of which mechanical stimulation acts as an important regulator. Very recent studies have shown a mutual effect between bone and other organs, which means bone influences the activity of other organs and is also influenced by other organs and systems of the body, especially the nervous system. With the discovery of neuropeptide (calcitonin gene-related peptide, vasoactive intestinal peptide, substance P, and neuropeptide Y) and neurotransmitter in bone and the adrenergic receptor observed in osteoclasts and osteoblasts, the function of peripheral nervous system including sympathetic and sensor nerves in bone resorption and its reaction to on osteoclasts and osteoblasts under mechanical stimulus cannot be ignored. Taken together, bone tissue is not only the mechanical transmitter, but as well the receptor of neural system under mechanical loading. This review aims to summarize the relationship among bone, nervous system, and mechanotransduction.