title: Nanotopography directs mesenchymal stem cells to osteoblast lineage through regulation of microRNA-SMAD-BMP-2 circuit.
abstract: The aim of this study was to investigate if chemically produced nanotopography on titanium (Ti) surface induces osteoblast differentiation of cultured human bone marrow mesenchymal stem cells (hMSCs) by regulating the expression of microRNAs (miRs). It was demonstrated that Ti with nanotopography induces osteoblast differentiation of hMSCs as evidenced by upregulation of osteoblast specific markers compared with untreated (control) Ti at day 4. At this time-point, miR-sequencing analysis revealed that 20 miRs were upregulated (>twofold) while 20 miRs were downregulated (>threefold) in hMSCs grown on Ti with nanotopography compared with control Ti. Three miRs, namely miR-4448, -4708, and -4773, which were significantly downregulated (>fivefold) by Ti with nanotopography affect osteoblast differentiation of hMSCs. These miRs directly target SMAD1 and SMAD4, both key transducers of the bone morphogenetic protein 2 (BMP-2) osteogenic signal, which were upregulated by Ti with nanotopography. Overexpression of miR-4448, -4708, and 4773 in MC3T3-E1 pre-osteoblasts noticeably inhibited gene and protein expression of SMAD1 and SMAD4 and therefore repressed the gene expression of key bone markers. Additionally, it was observed that the treatment with BMP-2 displayed a higher osteogenic effect on MC3T3-E1 cells grown on Ti with nanotopography compared with control Ti, suggesting that the BMP-2 signaling pathway was more effective on this surface. Taken together, these results indicate that a complex regulatory network involving a miR-SMAD-BMP-2 circuit governs the osteoblast differentiation induced by Ti with nanotopography. J. Cell. Physiol. 229: 1690-1696, 2014. © 2014 Wiley Periodicals, Inc.
authors.affiliation: Cell Culture Laboratory, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Rogerio B
authors.initials: RB
authors.lastname: Kato
authors.forename: Bhaskar
authors.initials: B
authors.lastname: Roy
authors.forename: Fabiola S
authors.initials: FS
authors.lastname: De Oliveira
authors.forename: Emanuela P
authors.initials: EP
authors.lastname: Ferraz
authors.forename: Paulo T
authors.initials: PT
authors.lastname: De Oliveira
authors.forename: Austin G
authors.initials: AG
authors.lastname: Kemper
authors.forename: Mohammad Q
authors.initials: MQ
authors.lastname: Hassan
authors.forename: Adalberto L
authors.initials: AL
authors.lastname: Rosa
authors.forename: Marcio M
authors.initials: MM
authors.lastname: Beloti
mesh_terms: D000469:Alkaline Phosphatase / Q000235:genetics / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D055396:Bone Morphogenetic Protein 2 / Q000235:genetics* / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D002460:Cell Line; D019070:Cell Lineage / Q000187:drug effects / Q000235:genetics; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics / Q000378:metabolism; D005260:Female; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D051379:Mice; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008875:Middle Aged; D053758:Nanoparticles / Q000737:chemistry*; D010006:Osteoblasts / Q000166:cytology*; D015675:Osteocalcin / Q000378:metabolism; D053495:Osteopontin / Q000378:metabolism; D051785:Smad Proteins / Q000235:genetics*; D014025:Titanium / Q000494:pharmacology; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics
chemical_list: D015415:Biomarkers; D055396:Bone Morphogenetic Protein 2; D050659:Core Binding Factor Alpha 1 Subunit; D035683:MicroRNAs; C493709:RUNX2 protein, human; D051785:Smad Proteins; D015675:Osteocalcin; D053495:Osteopontin; D014025:Titanium; D000469:Alkaline Phosphatase