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| Author(s): |
Ricardo Bonfante
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba |
| Defense date: | 2016-02-24 |
| Examining board members: |
Juliana Trindade Clemente Napimoga;
Heloísa Helena de Araújo Ferreira;
Ana Cláudia Rossi
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| Advisor: | Juliana Trindade Clemente Napimoga |
| Abstract | |
The temporomandibular joint (TMJ) is affected in 65% of patients with arthritis and pain is the primary complaint, especially during movement and function. The microglial cells responsible for innate immunity in the central nervous system are related as an important factor in the induction and maintenance of sensory disturbances followed by neuronal disorders or peripheral tissue injury or caused by chronic diseases, such as arthritis. This study standardized a protocol to induce albumin induced arthritis in the TMJ of rats and evaluated microglial cells of the trigeminal subnucleus caudalis (Vc) in the induction and development of persistent inflammatory hyperalgesia by the proposed protocol. Male Wistar rats (n=40) were sensitized by a subcutaneous injection of methylated bovine serum albumin (mBSA, 500?g) in an emulsion containing a phosphate buffered saline (PBS) and complete Freund's adjuvant (CFA). The mBSA dissolved in incomplete Freund's adjuvant (IFA) was injected at different sites on the back of the animals 7 and 14 days after the first immunization. Twenty-one days after the initial injection, albumin induced arthritis was induced in the TMJ of the immunized animals by an intra-articular injection of mBSA (Challenge) (10?g/TMJ/week) during 3 weeks. The hyperalgesia generated by the albumin induced arthritis in the TMJ was assessed by the nociceptive behavior of the animals by an intra-articular injection of a low dose of formalin (0.5%) 24 hours, 7 and 14 days after the last intra-articular injection of mBSA. After the behavioral testing, animals were euthanized and periarticular tissues and Vc removed for further analysis. The model of albumin induced arthritis in the TMJ of rats resulted in an increased nociceptive response observed 7 and 14 days after the last intra-articular injection of mBSA (p<0.05: ANOVA, Tukey test). It was observed that the nociceptive response is associated with a significant increase in the release of IL-12, IL-18 and ICAM-1 expression in periarticular tissues. There was no difference for the microglial expression (CD11b/c) and in the activation of p38 MAPK (p>0.05: ANOVA, Bonferroni test) between the tested groups. However, it was observed a significant increase in the release of Cathepsin S and Fractalkine in the Vc of the immunized animals 14 days after the experimental protocol (p<0.05: ANOVA, Bonferroni test). The expression of P2X7 receptor was found significantly increased on days 7 and 14 when compared to the control group (p<0.05: ANOVA, Bonferroni test). This new protocol of albumin induced arthritis in the TMJ of rats showed to be effective for the study of the mechanisms involved in the induction and maintenance of inflammatory pain in the generates changes in the activity of microglial cells of the Vc (AU) | |
| FAPESP's process: | 14/09975-7 - Evaluation of microglial cells involvement in induction and persistence of inflammatory hypernociception induced by rheumatoid arthritis in rats TMJ |
| Grantee: | Ricardo Bonfante |
| Support Opportunities: | Scholarships in Brazil - Master |