Related Experiment Video
Updated: Aug 27, 2026

Accessing the Cytotoxicity and Cell Response to Biomaterials
Published on: July 8, 2021
Proliferation of dental pulp fibroblasts in response to thrombin involves mitogen-activated protein kinase signalling
R Gruber1, C Jindra, B Kandler
1Department of Oral Surgery, School of Dentistry, University of Vienna, Austria. reinhard.gruber@akh-wien.ac.at
Aim:
To examine the involvement of mitogen-activated protein kinases (MAPK) signalling on thrombin-stimulated human dental pulp fibroblasts (DPF).
Methodology:
Dental pulp fibroblasts were isolated from dental pulp connective tissue of third molars and expanded in vitro. Expression of thrombin receptors was analysed by RT-PCR, and cell proliferation was measured by 3[H]-thymidine incorporation assay. Phosphorylation levels of MAPK were determined by Western blot analysis, and alkaline phosphatase activity was measured to serve as a marker for odontogenic differentiation. Statistical analysis was performed by Student's t-test.
Results:
Dental pulp fibroblasts express the thrombin receptors protease-activated receptor-1 (PAR-1), PAR-3 and PAR-4. Measurement of 3[H]-thymidine incorporation revealed a dose-dependent increase of DNA synthesis in response to thrombin treatment. The thrombin-induced mitogenic activity was decreased by the extracellular signal-regulated protein kinase (ERK) signalling inhibitor PD98059 (P < 0.05), and by SB203580 (P < 0.05), a p38 MAPK inhibitor. Western blot analysis demonstrated increased phosphorylation of ERK in DPF following stimulation with thrombin, while p38 MAPK and c-Jun NH2-terminal kinase (JNK) were not activated. Alkaline phosphatase activity of DPF remained unchanged upon incubation with thrombin.
Conclusions:
These results suggest that signalling via MAPK mediates the mitogenic activity of thrombin on DPF and may thus play a role during the early stages of pulp repair.
Related Concept Videos
Intracellular Signaling Affects Focal Adhesions
Some...
Mitogens and the Cell Cycle
TGF - β Signaling Pathway
Clot Retraction and Fibrinolysis
MAPK Signaling Cascades
Regulation of Angiogenesis and Blood Supply

