title: Time-lapse Raman imaging of osteoblast differentiation.
abstract: Osteoblastic mineralization occurs during the early stages of bone formation. During this mineralization, hydroxyapatite (HA), a major component of bone, is synthesized, generating hard tissue. Many of the mechanisms driving biomineralization remain unclear because the traditional biochemical assays used to investigate them are destructive techniques incompatible with viable cells. To determine the temporal changes in mineralization-related biomolecules at mineralization spots, we performed time-lapse Raman imaging of mouse osteoblasts at a subcellular resolution throughout the mineralization process. Raman imaging enabled us to analyze the dynamics of the related biomolecules at mineralization spots throughout the entire process of mineralization. Here, we stimulated KUSA-A1 cells to differentiate into osteoblasts and conducted time-lapse Raman imaging on them every 4 hours for 24 hours, beginning 5 days after the stimulation. The HA and cytochrome c Raman bands were used as markers for osteoblastic mineralization and apoptosis. From the Raman images successfully acquired throughout the mineralization process, we found that β-carotene acts as a biomarker that indicates the initiation of osteoblastic mineralization. A fluctuation of cytochrome c concentration, which indicates cell apoptosis, was also observed during mineralization. We expect time-lapse Raman imaging to help us to further elucidate osteoblastic mineralization mechanisms that have previously been unobservable.
authors.affiliation: Department of Applied Physics, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Hashimoto
authors.affiliation: Institute of Photonics and Biomedicine, Graduate School of Science, East China University of Science and Technology, 130 Meilong Rd., Shanghai, 200237, China.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Yamaguchi
authors.affiliation: Department of Applied Physics, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Liang-da
authors.initials: LD
authors.lastname: Chiu
authors.affiliation: Department of Periodontology, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Chiaki
authors.initials: C
authors.lastname: Morimoto
authors.affiliation: Department of Applied Physics, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Katsumasa
authors.initials: K
authors.lastname: Fujita
authors.affiliation: Department of Periodontology, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Masahide
authors.initials: M
authors.lastname: Takedachi
authors.affiliation: Department of Applied Physics, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kawata
authors.affiliation: Department of Periodontology, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Murakami
authors.affiliation: Department of Applied Physics, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors.forename: Eiichi
authors.initials: E
authors.lastname: Tamiya
mesh_terms: D000818:Animals; D002113:Calcification, Physiologic / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D045304:Cytochromes c / Q000378:metabolism; D051379:Mice; D008853:Microscopy / Q000379:methods*; D010006:Osteoblasts / Q000166:cytology* / Q000502:physiology*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D059008:Time-Lapse Imaging / Q000379:methods*; D019207:beta Carotene / Q000378:metabolism
chemical_list: D019207:beta Carotene; D045304:Cytochromes c