title: Texture analyses show synergetic effects of biomechanical and biochemical stimulation on mesenchymal stem cell differentiation into early phase osteoblasts.
abstract: We investigated the structural complexity and texture of the cytoskeleton and nucleus in human mesenchymal stem cells during early phase differentiation into osteoblasts according to the differentiation-induction method: mechanical and/or chemical stimuli. For this, fractal dimension and a number of parameters utilizing the gray-level co-occurrence matrix (GLCM) were calculated based on single-cell images after confirmation of differentiation by immunofluorescence staining. The F-actin and nuclear fractal dimensions were greater in both stimulus groups compared with the control group. The GLCM values for energy and homogeneity were lower in fibers of the F-actin cytoskeleton, indicating a dispersed F-actin arrangement during differentiation. In the nuclei of both stimulus groups, higher values for energy and homogeneity were calculated, indicating that the chromatin arrangement was chaotic during the early phase of differentiation. It was shown and confirmed that combined stimulation with mechanical and chemical factors accelerated differentiation, even in the early phase. Fractal dimension analysis and GLCM methods have the potential to provide a framework for further investigation of stem cell differentiation.
authors.affiliation: Department of Biomedical Engineering, Inje University, Gimhae, Gyeongnam, 621-749, Korea.
authors.forename: So Hee
authors.initials: SH
authors.lastname: Park
authors.affiliation: Cardiovascular and Metabolic Disease Center, Inje University, Busan, 633-165, Korea.
authors.forename: Ji Won
authors.initials: JW
authors.lastname: Shin
authors.affiliation: Department of Biomedical Engineering, Inje University, Gimhae, Gyeongnam, 621-749, Korea.
authors.forename: Yun Gyeong
authors.initials: YG
authors.lastname: Kang
authors.affiliation: Department of Biomedical Engineering, Inje University, Gimhae, Gyeongnam, 621-749, Korea.
authors.forename: Jin-Sook
authors.initials: JS
authors.lastname: Hyun
authors.affiliation: Department of Biomedical Engineering, Inje University, Gimhae, Gyeongnam, 621-749, Korea.
authors.forename: Min Jae
authors.initials: MJ
authors.lastname: Oh
authors.affiliation: Department of Biomedical Engineering, Inje University, Gimhae, Gyeongnam, 621-749, Korea.
authors.forename: Jung-Woog
authors.initials: JW
authors.lastname: Shin
mesh_terms: D001696:Biomechanical Phenomena / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology*; D002467:Cell Nucleus / Q000502:physiology; D003599:Cytoskeleton / Q000502:physiology; D017709:Fractals; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000502:physiology; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D010006:Osteoblasts / Q000166:cytology* / Q000502:physiology