Cellular differentiation can be affected by the extracellular environment, particularly extracellular substrates. The nanotopography of the substrate may be involved in the mechanisms of cellular differentiation in vi...Cellular differentiation can be affected by the extracellular environment, particularly extracellular substrates. The nanotopography of the substrate may be involved in the mechanisms of cellular differentiation in vivo. Organelles are major players in various cellular functions; however, the influence of nano- topography on organelles has not yet been elucidated. In the present study, a micropit-nanotube topography （MNT） was fabricated on the titanium surface, and organelle-specific fluorescent probes were used to detect the intracellular organelle organization of MG63 cells. Communication between organelles, identified by organelle-specific GTPase expression, was evaluated by quantitative polymerase chain reaction and western blotting. Transmission electron microscopy was performed to evaluate the organelle structure. There were no significant differences in organelle distribution or number between the MNT and flat surface. However, organelle-specific GTPases on the MNT were dramatically downregulated. In addition, obvious endoplasmic reticulum lumen dilation was observed on the MNT surface, and the unfolded protein response （UPR） was also initiated. Regarding the relationships among organelle trafficking, UPR, and osteogenic differentiation, our findings may provide important insights into the signal transduction induced by nanotopography.展开更多
基金This work was granted by the National Natural Science Foundation of China （Nos. 81470785 and 81530051） and Program for Changjiang Scholars and Innovative Research Team in University （No. IRT13051）. We appreciate the grant from Department of Oral and Maxillofacial Surgery, School of Stomatology, the Fourth Military Medical University. The authors also thank the help from Department of Toxicology, the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, Shaanxi Provincial Key Lab of Free Radical Biology and Medicine, School of Public Health.
文摘Cellular differentiation can be affected by the extracellular environment, particularly extracellular substrates. The nanotopography of the substrate may be involved in the mechanisms of cellular differentiation in vivo. Organelles are major players in various cellular functions; however, the influence of nano- topography on organelles has not yet been elucidated. In the present study, a micropit-nanotube topography （MNT） was fabricated on the titanium surface, and organelle-specific fluorescent probes were used to detect the intracellular organelle organization of MG63 cells. Communication between organelles, identified by organelle-specific GTPase expression, was evaluated by quantitative polymerase chain reaction and western blotting. Transmission electron microscopy was performed to evaluate the organelle structure. There were no significant differences in organelle distribution or number between the MNT and flat surface. However, organelle-specific GTPases on the MNT were dramatically downregulated. In addition, obvious endoplasmic reticulum lumen dilation was observed on the MNT surface, and the unfolded protein response （UPR） was also initiated. Regarding the relationships among organelle trafficking, UPR, and osteogenic differentiation, our findings may provide important insights into the signal transduction induced by nanotopography.
