No abstract

A new field of dental medicine seeks to exploit nature's solution for repairing damaged tissues, through the process of regeneration. Most adult mammalian tissues have limited regenerative capacities, but in lower vertebrates, the molecular machinery for regeneration is an elemental part of their genetic makeup. Accumulating data suggest that the molecular pathways responsible for the regenerative capacity of teleosts, amphibians, and reptiles have fallen into disuse in mammals but that they can be "jumpstarted" by the selective activation of key molecules. The Wnt family of secreted proteins constitutes one such critical pathway: Wnt proteins rank among the most potent and ubiquitous stem cell self-renewing factors, with tremendous potential for promoting human tissue regeneration. Wnt reporter and lineage-tracing strains of mice have been employed to create molecular maps of Wnt responsiveness in the craniofacial tissues, and these patterns of Wnt signaling colocalize with stem/progenitor populations in the rodent incisor apex, the dental pulp, the alveolar bone, the periodontal ligament, the cementum, and oral mucosa. The importance of Wnt signaling in both the maintenance and healing of these craniofacial tissues is summarized, and the therapeutic potential of Wnt-based strategies to accelerate healing through activation of endogenous stem cells is highlighted.

No abstract

No abstract

The collapse of lubrication function caused by changes of synovial fluid (SF) is regarded as the main aetiology of temporomandibular disorders (TMD). Hyaluronan (HA) is one of the principal components of SF. Both physicochemical properties and cell biological functions of HA mainly depend on its molecular size. The present study was designed to analyse the HA molecular size and boundary-lubricating ability of SF in the patients with TMD and compare them with that from normal controls. Temporomandibular disorders patients were divided into three subgroups: displaced disc with reduction (DDR), disc without reduction (DDNR) and disc perforation (DP). After obtaining SF samples, we analysed the molecular size of HA by high-performance liquid chromatography, and boundary-lubricating ability (coefficient of friction, COF) of SF by a friction apparatus. The results suggested that there was no significant difference in molecular size of HA among the groups of health control, DDR and DDNR, while the DP group presented a lower molecular size when compared to other ones. Boundary-lubricating ability test showed that COF of SF in TMD patients were significantly higher than that of healthy controls. In the patients' subgroups, no statistical difference was observed between the group of DDR and DDNR, while DP group presented a higher COF when compared to the group of DDR or/and DDNR. Collectively, the increased values of COF, which corresponded to the decrease of HA molecular size, indicated that the distinct changes of HA molecular size and boundary-lubricating ability in the SF occurred with TMD.