Dentin-derived BMP-2 and Odontoblast Differentiation

Abstract

It is known that stem cells from exfoliated deciduous teeth (SHED) can be induced to differentiate into odontoblasts. However, the nature of dentin-derived morphogenic signals required for dental pulp stem cell differentiation remains unclear. The hypothesis underlying this work is that dentin-derived Bone Morphogenetic Proteins (BMP) are necessary for the differentiation of SHED into odontoblasts. We observed that SHED express markers of odontoblastic differentiation (DSPP, DMP-1, MEPE) when seeded in human tooth slice/scaffolds and cultured in vitro, or implanted subcutaneously into immunodeficient mice. In contrast, SHED cultured in deproteinized tooth slice/scaffolds, or scaffolds without a tooth slice, do not express these markers. SHED express the BMP receptors BMPR-IA, BMPR-IB, and BMPR-II. Notably, blockade of BMP-2 signaling inhibited the expression of markers of odontoblastic differentiation by SHED cultured in tooth slice/scaffolds. Collectively, this work demonstrates that dentin-derived BMP-2 is required to induce the differentiation of SHED into odontoblasts.

Effect of EDTA on TGF-β1 released from the dentin matrix and its influence on dental pulp stem cell migration

“…4,8 In contrast, PBS was chosen due to its inability to properly dissolve the mineral or organic components of dentin. 4,8 Considering that NaOCl denatures proteins found in the dentin matrix, 17 we employed this solution for five days to remove the organic content from dentin in an attempt to eliminate the effect of dentin matrix molecules on SHED. As expected, EDTA was a significantly more effective extractant of TGF-b1 than PBS and NaOCl.…”

“…4 Two irrigants currently used during cleaning and shaping of the root canal are ethylenediaminetetraacetic acid (EDTA) 13 and sodium hypochlorite (NaOCl). 14, 15,16,17 EDTA is a final irrigant that causes dentin demineralization and provides excellent cleaning of the canal walls. 13 It acts on the inorganic components of the smear layer, leading to decalcification of the peri-and intertubular dentin.…”

“…18 NaOCl is an auxiliary irrigant that is used during root canal instrumentation to promote debridement, lubrication, disinfection, tissue dissolution, collagen layer removal and dentin dehydration ,14, 15,16 and that also causes protein denaturation. 17 EDTA condit ion i ng of dent i ne promotes adhesion, migration and differentiation of the pulp stem cells from permanent teeth. 3 In addition, various soluble proteins extracted from the dentine matrix are able to exert a direct biological effect on dental pulp stem cells in promoting mineralized tissue repair mechanisms.…”

Influence of Poly-L-Lactic Acid Scaffold's Pore Size on the Proliferation and Differentiation of Dental Pulp Stem Cells

“…Teeth were transversely sectioned at the cervical region with a diamond blade at low speed under cooling with sterile phosphate-buffered saline (PBS) to obtain 1-mm thick tooth slices. The pulp tissue was thoroughly removed with sterile forceps and the dentin was conditioned for 1 min with ethylenediamine tetraacetic acid (EDTA) and washed again with PBS (18). Sodium chloride was sieved (150-250 µm and 250-425mm) and filled the pulp chamber.…”

“…In addition, for bone tissue engineering a range of pore sizes comprising 100-150 and 150-200 µm have shown substantial bone ingrowth, while a smaller range (75-100 µm) results in the formation of an non-mineralized osteoid tissue (14,17). Besides, DPSC are able to attach and proliferate into PLLA scaffolds with a pore size ranging from 250-425 µm, prepared in a tooth slice/scaffold (TS/S) model and produce a de novo pulp-like tissue (10,18). Therefore, this study aims to evaluate the influence of PLLA scaffold's pore size on the proliferation and differentiation of DPSC using the TS/S model.…”