Gene expression of growth factors with angiogenic potential in human dental pulp tissue from teeth with complete and incomplete root development.

AIM: To quantify the expression of angiogenic growth factors (ANG2, VEGFA, TGFß1) and their corresponding receptors (VEGFR1, VGFR2, NRP1 and TGFßR1) in human dental pulps from extracted third molars with complete and incomplete root development. METHODOLOGY: Fifty-six dental pulp samples obtained from freshly extracted human third molars were divided equally into two groups according to their stage of root development; 28 third molars with complete root development and 28 third molars with incomplete root development. All samples were processed and total RNA was extracted, cDNA was then synthetized for each sample and the target genes expression profiles for ANG2, VEGFA, VEGFR1, VEGFR2, NRP1, TGFß1 and TGFßR1 were obtained by RT2-PCR. The data was analysed with a Student's t-test to compare the replicate ∆∆Ct values for each gene. RESULTS: Teeth with incomplete root development were associated with a significantly greater gene expression of TGFßR1 (P = 0.03), whereas in teeth with complete root development the genes that had significantly greater expression were VEGFA (P = 0.04). CONCLUSION: The angiogenic growth factors (ANG2, VEGFA, TGFß1) and their receptors (NRP1, VEGFR1, VEGFR2 and TGFßR1) were expressed in pulps of teeth with complete and incomplete root development measured by RT2-PCR, with TGFBR1 genes being significantly different in teeth with incomplete root development and VEGFA genes in teeth with complete root development.

Angiogenic mechanisms of human dental pulp and their relationship with substance P expression in response to occlusal trauma.

Angiogenesis is the formation of new blood vessels based on a pre-existing vasculature. It comprises two processes, sprouting of endothelial cells and the division of vessels due to abnormal growth of the microvasculature. It has been demonstrated that substance P (SP) can induce angiogenesis either by modulating endothelial cell growth (direct mechanism) or by attracting cells with angiogenic potential to the injury site (indirect mechanism). Therefore, the purpose of this article is to review the angiogenic mechanisms that regulate mineralized tissue formation in human dental pulp tissue and their relationship with SP expression as a defence response to stimuli such as the masticatory function and occlusal trauma. Articles included in this review were searched in PubMed, Scopus and ISI Web of Science databases, combining the following keywords: human dentine pulp, angiogenesis, angiogenic growth factors, neuropeptides, substance P, neurogenic inflammation, dentine matrix, dentinogenesis, occlusal trauma and dental occlusion. It is concluded that human dental pulp tissue responds to occlusal trauma and masticatory function with a neurogenic inflammatory phenomenon in which SP plays an important role in the direct and indirect mechanisms of angiogenesis by the action evoked via NK1 receptors at different cells, such as fibroblasts, endothelial and inflammatory cells, leading to new blood vessel formation which are needed to stimulate mineralized tissue formation as a defence mechanism.