title: Nano-topography sensing by osteoclasts.
abstract: Bone resorption by osteoclasts depends on the assembly of a specialized, actin-rich adhesive 'sealing zone' that delimits the area designed for degradation. In this study, we show that the level of roughness of the underlying adhesive surface has a profound effect on the formation and stability of the sealing zone and the associated F-actin. As our primary model substrate, we use 'smooth' and 'rough' calcite crystals with average topography values of 12 nm and 530 nm, respectively. We show that the smooth surfaces induce the formation of small and unstable actin rings with a typical lifespan of approximately 8 minutes, whereas the sealing zones formed on the rough calcite surfaces are considerably larger, and remain stable for more than 6 hours. It was further observed that steps or sub-micrometer cracks on the smooth surface stimulate local ring formation, raising the possibility that similar imperfections on bone surfaces may stimulate local osteoclast resorptive activity. The mechanisms whereby the physical properties of the substrate influence osteoclast behavior and their involvement in osteoclast function are discussed.
authors.affiliation: Department of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Dafna
authors.initials: D
authors.lastname: Geblinger
authors.forename: Lia
authors.initials: L
authors.lastname: Addadi
authors.forename: Benjamin
authors.initials: B
authors.lastname: Geiger
mesh_terms: D000042:Absorption / Q000187:drug effects; D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002119:Calcium Carbonate / Q000494:pharmacology; D002460:Cell Line; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D049329:Nanostructures / Q000737:chemistry*; D010010:Osteoclasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D013499:Surface Properties / Q000187:drug effects; D013997:Time Factors; D019096:Vitronectin / Q000378:metabolism / Q000494:pharmacology
chemical_list: D019096:Vitronectin; D002119:Calcium Carbonate