In vivo and in vitro radiotherapy increased dentin enzymatic activity

Author(s)

Cunha, Sandra Ribeiro ; Maravic, Tatjana ; Comba, Allegra ; Ramos, Pedro Augusto ; Tay, Franklin R. ; Pashley, David H. ; Fregnani, Eduardo Rodrigues ; Aranha, Ana Cecilia ; Mazzoni, Annalisa ; Breschi, Lorenzo

• Document type: Journal article
• Source: Journal of Dentistry; v. 100, p. 6-pg., 2020-09-01.

Abstract

Objectives: The present study investigated the effects of in vitro and in-vivo radiotherapy on endogenous enzy-matic activity in dentin using gelatin zymography and in-situ zymography. Methods: Gelatin zymographic assays were performed on protein extracts obtained from dentin powder of sound non-irradiated (NRT), in vitro irradiated (VTRT) and in vivo irradiated (VIRT) human teeth. Their proteolytic activities were quantified using band densitometric evaluation. For in-situ zymography, dentin specimens from NRT, VIRT and VTRT were covered with fluorescein-conjugated gelatin and examined with confocal laser -scanning microscopy. Fluorescence intensity emitted by the hydrolyzed fluorescein-conjugated gelatin was quantified and statistically analyzed. In-situ zymography data were statistically analyzed using Kruskal-Wallis ANOVA and Dunn's multiple comparison procedures (alpha = 0.05). Results: No difference between in vitro and in vivo radiotherapy treatment was found. Both VTRT and VIRT groups showed increase in MMP-9 expression when compared to NRT group. Significant increases (p < 0.05) in gelatinolytic activity (26 % for VTRT; 55 % for VIRT) were observed when compared to the NRT group. Conclusion: Radiotherapy increase endogenous enzymatic activity in non-restored dentin. (AU)

• FAPESP's process: 15/20297-3 - The effects of radiotherapy on the endogenous proteases of sound and restored dentin
• Grantee: Sandra Ribeiro de Barros da Cunha
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 17/01777-0 - The effects of ionizing radiation on the distribution of cysteine-cathepsins in restored and sound dentin
• Grantee: Sandra Ribeiro de Barros da Cunha
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate