Study of bisphosphonate effects on clastic cells during endochondral ossification in the rat knee and in primary cultures: morphological and molecular approaches.

Author(s)

Eloiza de Rezende

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2013-12-06

Examining board members

Victor Elias Arana Chavez; Jarbas Arruda Bauer; Luciane Portas Capelo; Cecilia Helena de Azevedo Gouveia Ferreira; Fernanda Paula Yamamoto Silva

• Advisor: Victor Elias Arana Chavez

Abstract

In endochondral ossification, clastic cells (Oc) resorb the calcified cartilage, while osteoblasts (Ob) form new bone. Bisphosphonates (Bps) inhibit the action of Oc. The effect of the Bps alendronate (Aln) and etidronate (Etn) on the knees of young rats (in vivo) and in primary cultures of Oc (in vitro) was evaluated. The specimens were analyzed by SEM, TEM, and LM or TRAP histochemistry. RNA was extracted to analysis by RT-PRC and protein to analysis by WB. RNA and protein were also extracted after the treatment of cultures with Bps. Rats treated with Etn exhibited a disorganized epiphyseal plate containing large area of cartilage; SEM showed few bone trabeculae with resorption lacunae, which were not observed in Aln specimens. Aln showed numerous latent Oc by TRAP histochemistry and TEM. In vivo, the Bps decreased the expression of all analyzed genes; in vitro, Aln decreased only the expression of Runx2 as well as SPP1, which expression was less with Etn. Protein expression varied among the groups. Aln is more potent for inhibiting the Oc, while Etn acts on Ob. (AU)

• FAPESP's process: 10/07509-8 - "IN VIVO" AND IN PRIMARY CULTURE STUDY OF THE EFFECT ON BISPHOSPHONATES ON CLASTIC CELLS DURING THE ENDOCHONDRAL OSSIFICATION OF RAT KNEES
• Grantee: Eloiza de Rezende
• Support Opportunities: Scholarships in Brazil - Doctorate