Effects of fluoxetine on immunoinflammatory responses associated with periodontal disease

Author(s)

Luciana Salles Branco de Almeida

• Document type: Doctoral Thesis
• Press: Piracicaba, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba
• Defense date: 2011-01-21

Examining board members

Pedro Luiz Rosalen; Antonio Luiz Amaral Pereira; Marcia Pinto Alves Mayer; Carina Deny; Karina Cogo Müller

• Advisor: Pedro Luiz Rosalen; Gilson Cesar Nobre Franco

Abstract

Fluoxetine is a selective serotonin reuptake inhibitor presenting immunomodulatory and anti-inflammatory properties. The aim of this study was to evaluate the fluoxetine effects on immunoinflammatory response associated with periodontal disease (PD). The in vitro study evaluated the effects of fluoxetine on antigen-presentation capacity of dendritic cells (DCs). Bone marrow DCs obtained from C57BL/6 wild type mice were differentiated using GM-CSF (20 ng/mL). DCs were treated with fluoxetine (concentrations of 0.01, 0.1 or 1 ?M) for subsequent cytokine/chemokine assays (ELISA) and analysis of expression of MHC-class II and co-stimulatory molecules (CD80, CD86, PD-L1, ICOS-L) to T cell activation using flow cytometry. Fluoxetine was also applied to cultures with both DCs and Aggregatibacter actinomycetemcomitans (Aa)-reactive T cells (×Aa-T), which were used for analysis of T cells proliferation/activation using thymidine and ELISA assays. Desipramine, a selective norepinephrine reuptake inhibitor, was also tested in vitro for comparison to fluoxetine. In vivo, male Wistar rats received ligature placement around mandibular first molars and were randomly assigned into three experimental groups (n=10/group): 1) Control rats (without ligature); 2) rats with ligature + placebo (saline; oral gavage); 3) rats with ligature + fluoxetine (20 mg/kg/day in saline; oral gavage). Histometric and histological analyses were performed for measurement of loss of bone in furcation region (H&E stain) and collagen fibers (picrosirius red stain) in the connective tissue of rats submitted to 15 days of PD induction. Gingival tissues were collected from animals submitted to 3 days of PD induction for analyses of mRNA expression of IL-1?, COX-2, MMP-9 and iNOS using RT-PCR, measurement of total protein concentration and MMP-9 activity using zymogram. Fluoxetine suppressed IL 12, IL-1?, TNF-?, RANTES and MIP-1??production by LPS-stimulated DCs (P < 0.05, ANOVA, Student's t test), as well as significantly reduced the expression of ICOS-L. Fluoxetine suppressed the proliferation of ×Aa-T stimulated with Aa-antigen presentation by DCs from co-cultures. When applied to ×Aa-T/DCs co-cultures, serotonin (5-HT) increased T cell proliferation, indicating that fluoxetine effects are independent of 5-HT. Desipramine effects were similar to those of fluoxetine. In the in vivo study, fluoxetine reduced alveolar bone loss as compared to ligature group (P < 0.05, ANOVA, Student's t test) and maintained collagen fibers levels similarly to control group (P > 0.05). Fluoxetine reduced IL-1??and COX-2 expression, as well as MMP-9 activity, from gingival tissues when compared to ligature group (P < 0.05). Altogether, data showed that fluoxetine can modulate the antigenpresentation capacity of DCs and reduce inflammatory response and loss of bone and collagen associated with PD. In conclusion, fluoxetine can modulate both immune and inflammatory responses on PD, suggesting that it may constitute a new therapeutic approach for modulation of host response in periodontal therapy (AU)

• FAPESP's process: 08/00566-6 - In vivo evaluation of the activity of fluoxetine and desipramine in host response in periodontal disease
• Grantee: Luciana Salles Branco de Almeida
• Support Opportunities: Scholarships in Brazil - Doctorate