Uniaxial cyclic tensile stretch inhibits osteogenic and odontogenic differentiation of human dental pulp stem cells. J Tissue Eng Regen Med

State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University, Chengdu, People's Republic of China.
Journal of Tissue Engineering and Regenerative Medicine (Impact Factor: 5.2). 05/2011; 5(5):347-53. DOI: 10.1002/term.319
Source: PubMed


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.

14 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: Dental pulp tissue contains stem cells that can differentiate into multiple lineages under specific culture conditions; the origin of these dental pulp stem cells, however, is still unknown. Here we have utilized an α-SMA-GFP transgenic mouse model to characterize expression of a-smooth muscle actin (SMA)-GFP in subpassages of pulp-tissue-derived dental pulp cells, as perivascular cells express α-SMA. During subculturing, percentages of cells expressing a-SMA increased significantly from passage 1 to 3. α-SMA-GFP-positive cells expanded faster than α-SMA-GFP-negative cells. The dental pulp cells at passage 3 were induced towards osteogenic, adipogenic or chondrogenic differentiation. All three differentiated cell lines expressed high levels of α-SMA (mineralized nodules, lipid droplets and chondrocyte pellets). GFP expression colocalized with differentiated osteoblasts, adipocytes and chondrocytes. Co-culturing the α-SMA-GFP-positive cells with human endothelial cells promoted formation of tube-like structures and robust vascular networks, in 3-D culture. Taken together, the a-SMA-GFP-positive cells were shown to have multilieange differentiation ability and to promote vascularization in a co-culture system with endothelial cells.
    Cell Proliferation 04/2012; 45(3):259-65. DOI:10.1111/j.1365-2184.2012.00818.x · 3.12 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Cells in situ are surrounded with defined structural elements formed by the nanomolecular extracellular matrix (ECM), and at the same time subjected to different mechanical stimuli arising from variety of physiological processes. In this study, using a nanotextured substrate mimicking the structural elements of the ECM and simulated microgravity, we wanted to develop a multifactorial model and understand better what guides cells in determining the morphological cell response. In our set-up, bone precursor cells from rat bone marrow were isolated and cultured on nanotextured polystyrene substrate (pitch 200 nm, depth 50 nm). Simulated microgravity was applied to the cells, using a random positioning machine (RPM). The results demonstrated that cells cultured on nanotextured substrate align parallel to the grooves and re-align significantly, but not completely, when subjected to simulated microgravity. The nanotextured substrate increased cell number and alkaline phosphatase (ALP) activity, whereas simulated microgravity decreased cells number and ALP activity. When the nanotextured substrate and simulated microgravity were combined together, the negative effect of the simulated microgravity ALP and cell number was reversed. In conclusion, absence of mechanical load in simulated microgravity has a negative effect on initial osteoblastogenesis, and nanotextured surfaces can partly reverse such a process. Copyright © 2012 John Wiley & Sons, Ltd.
    Journal of Tissue Engineering and Regenerative Medicine 09/2012; 8(12). DOI:10.1002/term.1600 · 5.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Dental pulp stem cells (DPSCs), which can differentiate into several types of cells, are subjected to mechanical stress by jaw movement and occlusal forces. In this study, we evaluated how the uniaxial mechanical stretch influences proliferation and differentiation of DPSCs. DPSCs were isolated and cultured from male Sprague-Dawley rats. Cultured DPSCs were identified by surface markers and the differentiation capabilities as adipocytes or osteoblasts. To examine the response to mechanical stress, uniaxial stretch was exposed to cultured DPSCs. We evaluated the impact of stretch on the intracellular signaling, proliferation, osteogenic differentiation, and gene expressions of DPSCs. Stretch increased the phosphorylation of Akt, ERK1/2, and p38 MAP kinase as well as the proliferation of DPSCs. The stretch-induced proliferation of DPSCs was abolished by the inhibition of the ERK pathway. On the other hand, stretch significantly decreased the osteogenic differentiation of DPSCs, but did not affect the adipogenic differentiation. We also confirmed mRNA expressions of osteocalcin and osteopontin were significantly suppressed by stretch. In conclusion, uniaxial stretch increased the proliferation of DPSCs, while suppressing osteogenic differentiation. These results suggest a crucial role of mechanical stretch in the preservation of DPSCs in dentin. Furthermore, mechanical stretch may be a useful tool for increasing the quantity of DPSCs in vitro for regenerative medicine.
    Tissue Engineering Part A 11/2012; 19(5-6). DOI:10.1089/ten.tea.2012.0099 · 4.64 Impact Factor
Show more