Human Odontoblast Culture Method: The Expression of Collagen and Matrix Metalloproteinases (MMPs)

Abstract

Studies on mature human odontoblasts have suffered for the lack of in vitro models. We recently introduced a human odontoblast and pulp tissue organ culture method, in which the odontoblasts are cultured in the pulp chamber after removal of the pulp tissue, and the pulp tissue can be cultured separately (Tjäderhane et al., 1998a). With this method, we have studied the effects of growth factors on the expression of collagen and extracellular matrix (ECM)-degrading enzymes, matrix metalloproteinases (MMPs), in mature human odontoblasts. TGF-beta 1 was selected because of its ability to regulate the response of the dentin-pulp complex to external irritation. The effect of TGF-beta 1 (10 ng/mL) on pro alpha 1(I) collagen mRNA was analyzed by quantitative PCR, and type I procollagen propeptide (PINP) was analyzed from conditioned culture media with RIA. Odontoblast media were also assayed for respective type III procollagen propeptide (PIIINP). TGF-beta had a negligible effect on collagen mRNA expression or protein synthesis, indicating that TGF-beta alone does not markedly induce dentin matrix formation per se in the human dentin-pulp complex (Palosaari et al., 2001). However, TGF-beta 1 seems to regulate MMP expression in mature human odontoblasts differentially. A strong down-regulation of MMP-8 (Palosaari et al., 2000), a modest down-regulation of MMP-20 (Tjäderhane et al., 2000), and considerable up-regulation of MMP-9, with no apparent effect on MMP-2 expression (Tjäderhane et al., 1998b), indicate that growth factors may affect the matrix synthesis by controlling the expression and activity of MMPs instead of collagen synthesis. The altered expression of MMPs may result in altered ECM formation, which in turn may contribute to the formation of atubular reparative dentin.

Microarray expression profiling of human dental pulp from single subject

“…11 In particular, growth factors like fibroblast growth factor may regulate the expression of collagen and extracellular matrix (ECM)-degrading enzymes, in mature human odontoblasts. 12 …”

Effect of accelerated aging on the bonding performance of fluoridated adhesive resins

“…MMPs are a family of host-derived proteolytic enzymes trapped within the mineralized dentin matrix that can hydrolyze the organic matrix of demineralized dentin [30][31][32] . Most MMPs are synthesized and released from odontoblasts in the form of proenzymes that require activation to degrade extracellular matrix components 33) . Unfortunately, they can also be activated by modern self-etch and etch-and-rinse adhesives 34,35) .…”

Aumento de longevidad de restauraciones de resinas compuestas y de su unión adhesiva. Revisión de tema

“…Es sabido que la matriz dentinaria contiene metaloproteinasas de la matriz (MMP) [135][136][137] El pre-tratamiento de la dentina con clorhexidina (CHX) al 0,2% durante 60 s, inhibe la actividad colagenolítica a niveles cercanos a cero 142 por medio de la inhibición de la actividad de las MMP en la capa híbrida aumentando su longevidad, lamentablemente estos estudios se han realizado in vivo por el período máximo de 14 meses, 143 observándose en Clases V, que no disminuye sus valores adhesivos. Otros compuestos como EDTA (ácido etilen diamino tetracético) además de la CHX ejercen la acción inhibitoria de las MMP en la degradación del colágeno en dentinas desmineralizadas, la degradación de las MMP fue reducida en dentina infiltrada con resina y la presencia de otro elemento como el zinc ejerció un efecto protector adicional.…”

“…It is well known that the dentin matrix contains matrix metalloproteinases (MMPs) [135][136][137] and that some of these MMPs attack collagen (MMP 8 and 20) and gelatin (MMP 2 and 9). 136,138 Dentin contains MMP 2 and 20, 138,139 and the activity of MMPs derived from host enzymes degrade the hybrid layer in vivo.…”