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Analysis of matrix metalloproteinase expression in glial cells satellites of the trigeminal ganglia of rats with persistent inflammation of the temporomandibular joint subjected to low intensity laser therapy

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Amanda de Carvalho Desiderá
Total Authors: 1
Document type: Doctoral Thesis
Press: Ribeirão Preto.
Institution: Universidade de São Paulo (USP). Faculdade de Odontologia de Ribeirão Preto
Defense date:
Examining board members:
Christie Ramos Andrade Leite Panissi; Thiago Mattar Cunha; Daniela Aparecida de Godoi Gonçalves; João Paulo Mardegan Issa; Luciano José Pereira
Advisor: Christie Ramos Andrade Leite Panissi

Pain is one of the main symptomatology able to lead individuals to seek medical and dental treatment. In dentistry it is estimated that about 40-75% of the population is a carrier of orofacial pain source and has at least one sign or symptom of temporomandibular disorders (TMD). The TMD corresponds to a pathological condition of multifactorial affecting the temporomandibular joint (TMJ) and masticatory muscles, causing pain in the orofacial region well as changes in the performance of mouth movements. The main sign of this disease is joint inflammation, which generates pain related structures. The inflammation leads to release of mediators such as substance P, calcitonin-related peptide gene (CGRP), and tumor necrosis factor (TNF-α) and interleukin-1β (IL-1β). These mediators sensitize terminal fiber nerves and nociceptive information goes to the first synaptic station, the trigeminal ganglion. The persistent inflammation when promotes the expression of metalloproteinase (MMP), whose operation modifies the extracellular matrix may therefore modulate neuronal pathways perception. Satellite glial cells (CSGs) are involved in neuronal microenvironment support, and possibly cells that act in the modulation of nociceptive pathways perception. Knowing deeper into the mechanisms of pain modulation, are sought noninvasive therapeutic effective to alleviate the painful symptoms arising from the DTM. The low level laser therapy (LLLT) is shown as an effective treatment, but their dose-dependent effect produces ambiguous results. In this context, this study aimed to verify the inflammatory biomarkers present in the synovial fluid in rats with persistent inflammation of the ATM, or not treated with LLLT. Wistar rats (200-240g, n = 440 - CEUA 2013.1.1111.58.7), which received CFA administration (Complete Freund\'s Adjuvant) or 0.9% saline (SAL) intraarticular and underwent (LLLT) or not applying laser temporomandibular region on the first day, 1 hour after inflammation induction, and after days 3, 5, 7 and 10. Our results showed that LLLT reduces polymorphonuclear cells present in the joint capsule of the TMJ, and also of reactive oxygen species (reduction in myeloperoxidase activity - MPO). Still, there was a reduction in expression of MMP-2 and MMP-9 in the synovial fluid of rats with persistent inflammation induced by the intraarticular administration of CFA. Pro-inflammatory cytokines (IL-1α, IL-1β, IL-6, IL-12p70, IFN-ϒ, GM-CSF and TNF-α) analyzed synovial fluid showed a significant increase in its expression induced by TMJ 20 inflammation, and LLLT reduced expression of these cytokines. However, the photostimulation in the absence of inflammation stimulated the expression of cytokines IL-2, IL-5, IL-12p70, GM-CSF. Furthermore, photodynamic therapy increased expression of anti-inflammatory cytokines IL-4, IL-10 and IL-13 in rats with TMJ inflammation. Analysis of immunofluorescence for MMP-2 and MMP-9 co-located to support cells showed that the most significant expression was located in neurons, and results indicate that LLLT at a dose of 60 J/cm² did not reduce the expression of these gelatinases in the ganglion trigeminal. (AU)

FAPESP's process: 13/15588-3 - Analysis of matrix metalloproteinases expression in satellite glial cells of the trigeminal ganglion of rats with persistent temporomandibular joint inflammation undergoing low level lasertherapy.
Grantee:Amanda de Carvalho Desiderá
Support type: Scholarships in Brazil - Doctorate