Dental stem cells

Abstract

Introduction: Teeth are complex organs containing two separate mineral and hard<br><br>tissues. Loosing teeth is not life threatening but it is important in clinic and<br><br>appearance. Today, new therapies are being used in modern dentistry, but they are not<br><br>completely successful. To overcome these problems, new approaches are being<br><br>developed to use stem cells and tissue engineering in order to repair and regenerate<br><br>teeth.<br><br>Teeth contain different stem cells with epithelial and mesenchymal origins. In this<br><br>review we will discuss dental mesenchymal stem cells.<br><br>Dental pulp stem cells (DPSCs): DPSCs are isolated from human dental pulp. These<br><br>adherent cells share same characters with BM-MSCs and exhibit high proliferation<br><br>and colony formation. They are multipotent and express MSCs markers like CD146<br><br>and STRO-1. DPSCs can differentiate into odontoblastic, adipogenic and osteoblastic<br><br>cell types. In vivo transplantation into immune compromised mice demonstrated the<br><br>ability of DPSCs to generate dentine/pulp-like complex. They could also differentiate<br><br>into active neurons and showed potential for cell therapy of neuronal disorders.<br><br>Stem cells from human exfoliated deciduous teeth (SHEDs): SHEDs are isolated<br><br>from pulp of human exfoliated deciduous teeth. They show high proliferation, colony<br><br>formation and differentiation capacity into odontoblasts, adipoctyes and neurons.<br><br>Compared with DPSCs, SHEDs exhibit higher proliferation rate, ability to form<br><br>spherical aggregates and can also generate bone in vivo and they are not capable of<br><br>generating dentine/pulp-like structure. It has been shown that transplantation of SHED<br><br>spheres into the striatum of parkinsonian rats partially improved the apomorphine<br><br>evoked rotation of behavioral disorders. These data suggested that SHEDs can be<br><br>considered as a source of stem cells in alleviating Parkinson\\\\\\\\\\\\\\'s disease.<br><br>Periodontal ligament stem cells (PDLSCs): Periodontal tissue plays the main role in<br><br>maintaining teeth and contains stem cells that show differentiation ability into<br><br>cementoblasts, adipocytes and fibroblasts. Like BM-MSCs, PDLSCs are CD146 and<br><br>STRO-1 positive and can form cementum/PDL-like structures, when they are<br><br>transplanted into immune compromised mice.<br><br>Root apical papilla stem cells (SCAPs): Dental papilla which has not developed<br><br>completely, contains MSCs that can differentiate into odontoblast-like cells. These<br><br>cells are called SCAPs. They also have the potential to differentiate into adipocytes<br><br>and neurons. Compared to DPSCs, SCAPs exhibit high proliferation capacity. By cotransplanting<br><br>SCAPs and PDLSCs into tooth sockets of mini pigs, dentine and<br><br>periodontal ligament were formed. These data showed that SCAPs, along with<br><br>PDLSCs, can generate biological root.<br><br>Concluding remarks: Despite all the progress, there are still lots of obstacles to use<br><br>stem cells in teeth regeneration and repair. Teeth are a viable source of adult<br><br>mesenchymal stem cells for a wide range of clinical applications. Dental pulp cells<br><br>grow well in culture and, interestingly, the proportion of cells with stem cell<br><br>properties appears to increase with passage.