Caspase‐3/caspase‐8, bax and bcl2 in pulps of human primary teeth with physiological root resorption

Abstract

OBJECTIVE. Physiological root resorption is a programmed event that takes place in primary teeth leading to elimination of all root structures. The mechanism behind pulp elimination indicates apoptosis, but its pathway has not been well characterised yet. To better understand this event, we evaluated the gene expression of bax, bcl-2, caspase-3 and caspase-8 through real-time polymerase chain reaction (PCR) and immunohistochemistry expression of Caspase-8 and Bax in pulps. METHODS. Samples were split into two groups: pulps from primary teeth with physiological root resorption (n = 40) and control (n =40), pulps from permanent teeth. Samples of each group were split into PCR (n = 20) and immunohistochemistry (n = 20). RESULTS. Pulps from primary teeth showed a higher caspase-3 mRNA level than pulps from permanent teeth. The expression of bax gene was more intense than caspase-8 but both did not show difference between groups. The bcl-2 mRNA level was incipient and similar between groups. Histopath slides did not show any evidence of inflammatory infiltration, which implies that extrinsic via is not likely to be involved. Immunohistochemistry reaction to Bax and Caspase-8 supported PCR results. CONCLUSIONS. Pulp apoptosis is likely to occur via caspase-3 activation through the mitochondrial pathway.

Caspase‑9 was involved in cell apoptosis in human dental pulp stem cells from deciduous teeth

“…Moreover, higher expression level of all three genes in the HDPSCs from deciduous teeth might indicate higher possibility of apoptosis pathways comparing with the HDPSCs from adult permanent teeth, though it needs further confirmation. The higher expression of caspase-3 in HDPSCs from deciduous teeth was consistent with previous study, while caspase-8 expression show some differences (21). The expression difference of caspase-8 might be due to the examined materials we used in this study instead of deciduous teeth and adult permanent teeth.…”

Dental findings in 14q terminal deletion syndrome

“…Homozygous deletions of JAG2 in mice cause severe craniofacial abnormalities (Jiang et al, 1998), and whereas heterozygous mice appear normal, DECIPHER (Firth et al, 2009) assigns JAG2 a haploinsufficiency index of 5.7%, strongly suggesting that dosage effects are different in humans compared with mice. SIVA1 in particular has been shown to induce apoptosis in a caspase-dependent manner (Py et al, 2004), and caspase activity has been detected in resorbing primary tooth pulp (Rodrigues et al, 2012). Impaired apoptosis, which has been suggested to play a role in pulp elimination during root resorption (Rodrigues et al, 2009), may contribute toward primary tooth over-retention because of haploinsufficiency of proapoptotic genes in the deleted region.…”

Advances in the Study of the Mechanisms of Physiological Root Resorption in Deciduous Teeth

“…Rodrigues et al proposed that apoptosis might be involved in the elimination of dental pulp during physiological root resorption ( 49 ). In order to better understand this event, they further explored the apoptotic pathway, suggesting that apoptosis of dental pulp cells in this physiological process was more likely to occur through the activation of caspase-3 by the mitochondrial pathway, an intrinsic pathway ( 50 ). The current understanding of the signaling system in apoptosis is still not comprehensive, and the relatively clear pathways of apoptosis mainly include intrinsic pathway mediated by mitochondria and extrinsic pathway mediated by death receptor ( 51 ).…”