A biophysical approach to quantify skeletal stem cells trans-differentiation as a model for the study of osteoporosis

• Published in: Biophysical chemistry Vol. 229; pp. 84 - 92
• Main Authors: Petecchia, L., Viti, F., Sbrana, F., Vassalli, M., Gavazzo, P.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-10-2017
• Subjects: Adipocyte; Adipocytes - cytology; Adipocytes - metabolism; Biophysical Phenomena; Bone Marrow Cells - cytology; Cell Differentiation; Cell Lineage; Cell Transdifferentiation; Cells, Cultured; Fatty Acid-Binding Protein 7 - genetics; Fatty Acid-Binding Protein 7 - metabolism; Holography; Humans; Imaging, Three-Dimensional; Mesenchymal Stromal Cells - cytology; Mesenchymal Stromal Cells - metabolism; Microscopy, Phase-Contrast; Models, Biological; Morphometry; Osteoblast; Osteoblasts - cytology; Osteoblasts - metabolism; Osteocalcin - genetics; Osteocalcin - metabolism; Osteoporosis - metabolism; Osteoporosis - physiopathology; Quantitative phase imaging; Real time qPCR; Real-Time Polymerase Chain Reaction; RNA - isolation & purification; RNA - metabolism; Tumor Suppressor Proteins - genetics; Tumor Suppressor Proteins - metabolism; Quantitative phase imaging; Osteoblast; Adipocyte; Real time qPCR; Morphometry
• ISSN: 0301-4622; 1873-4200
• DOI: 10.1016/j.bpc.2017.05.011

The stroma of human bone marrow contains a population of skeletal stem cells (hBM-MSC) which are common ancestors, among the others, of osteoblasts and adipocytes. It has been proposed that the imbalance between hBM-MSC osteogenesis and adipogenesis, which naturally accompanies bone marrow senescence, may contribute to the development of bone-associated diseases, like osteoporosis. The possibility to reproduce this mechanism in vitro has been demonstrated, providing a good model to disclose the details of the complex bone-fat generation homeostasis. Nevertheless, the lack of a simple approach to quantitatively assess the actual stage of a cellular population hindered the adoption of this in vitro model.
In this work, the direct differentiation of hBM-MSCs towards a single (osteo or adipo) lineage was characterized using quantitative biophysical and biological approaches, together with the parallel process of trans-differentiation from one lineage to the other. The results confirm that the original plasticity of hBM-MSCs is maintained along the initial stages of the differentiation, showing that in vitro conversion of pre-osteoblasts into adipocytes and, vice versa, of pre-adipocytes into osteoblasts is extremely efficient, comparable with the direct differentiation. Moreover, a method based on digital holography is proposed, providing a quantitative indication of the phenotype stage along differentiation.
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•Direct and trans-differentiation of pre-osteoblast in adipocyte behave similarly.•Trans-differentiation of pre-osteoblasts into adipocytes is extremely efficient.•Along the initial stages of differentiation hBM-MSCs maintain original plasticity.•QPI can support quantitative cell morphology studies.