Uniaxial cyclic tensile stretch inhibits osteogenic and odontogenic differentiation of human dental pulp stem cells.
ABSTRACT As the most important organs of occlusion, teeth are subjected to a variety of mechanical stresses. These stresses are transmitted into the dental pulp tissue and affect the dental pulp stem cells. In this study, human dental pulp stem cells were isolated from human impacted third molars and their multilineage differentiation abilities were tested. Human dental pulp stem cells were then exposed to cyclic tensile stretch. The results showed that the cyclic tensile stretch inhibited the expression of osteogenic marker genes and proteins such as BMP-2, OCN and ALP. Simultaneously, odontogenic marker genes and proteins such as DSPP, DSP and BSP were also inhibited by the mechanical stress. It was concluded that cyclic tensile stretch inhibits the osteogenic and odontogenic differentiation of dental pulp stem cells.
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ABSTRACT: Mechanical loading has been widely considered to be a crucial regulatory factor for growth plate development, but the exact mechanisms of this regulation are still not completely understood. In the growth plate, parathyroid hormone-related protein (PTHrP) regulates chondrocyte differentiation and longitudinal growth. Cyclic mechanical strain has been demonstrated to influence growth plate chondrocyte differentiation and metabolism, whereas the relationship between cyclic mechanical strain and PTHrP expression is not clear. The objective of this study was to investigate whether shortterm cyclic tensile strain regulates PTHrP expression in postnatal growth plate chondrocytes in vitro and to explore whether the organization of cytoskeletal F-actin microfilaments is involved in this process. To this end, we obtained growth plate chondrocytes from 2-week-old Sprague-Dawley rats and sorted prehypertrophic and hypertrophic chondrocytes using immunomagnetic beads coated with anti-CD200 antibody. The sorted chondrocytes were subjected to cyclic tensile strain of varying magnitude and duration at a frequency of 0.5 Hz. We found that cyclic strain regulates PTHrP expression in a magnitude- and time-dependent manner. Incubation of chondrocytes with cytochalasin D, an actin microfilament-disrupting reagent, blocked the induction of PTHrP expression in response to strain. The results suggest that short-term cyclic tensile strain induces PTHrP expression in postnatal growth plate prehypertrophic and hypertrophic chondrocytes and that PTHrP expression by these chondrocytes may subsequently affect growth plate development. The results also support the idea that the organization of cytoskeletal F-actin microfilaments plays an important role in mechanotransduction.Bone 07/2013; · 4.46 Impact Factor
Dataset: Hata Tissue Eng Part A 2012
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ABSTRACT: Background: Stem cells due to their great potential in tissue engineering can take place between the various treatment techniques established. A lot of research on these cells and the effect of various chemical and mechanical stimuli is done, that mechanical forces have a non-negligible contribution. The purpose of this study was to investigate the effects of the mechanical forces on differentiation of mesenchymal stem cells in to different lineage during the recent 12 years. Method and materials: In this systematic review, using PUBMED database and searching topics like “human mesenchymal stem cell”, “strain,”, “mechanical loading,”, “differentiation”, in the literature from 2000 to July 2012, studies evaluating the effects of mechanical forces on differentiation of human mesenchymal stem cells were studied. Results: In total, 46 articles were evaluated qualitatively. In most studies, the mechanical forces were lead to expected differentiation. Studies show that the combination of two forces will be increased differentiation. Amount of applied strain has critical effect on the type of differentiation. Conclusion: On the basis of this literature review, we can conclude that modern advances in the field of application of mechanical forces on stem cells can be used in order to improve tissue engineering treatments. Key words : Human Mesenchymal stem cell, strain, mechanical loading, differentiationJournal of Islamic Dental Association of Iran. 01/2013; 25(4).