Juliana Trindade Clemente-Napimoga

T-Helper Cell Type 17/Regulatory T-Cell Immunoregulatory Balance in Human Radicular Cysts and Periapical Granulomas

INTRODUCTION Cysts and granulomas are chronic periapical lesions mediated by a set of inflammatory mediators that develop to contain a periapical infection. This study analyzed the nature of the inflammatory infiltrate, presence of mast cells, and in situ expression of cytokines (interleukin [IL]-17 and transforming growth factor [TGF]-beta), chemokines (macrophage inflammatory protein [MIP]-1beta and monocyte chemotactic protein [MCP]-1), and nuclear transcription factor (FoxP3) in human periapical granulomas and cysts compared with a control group. METHODS Fifty-five lesions (25 periapical cysts, 25 periapical granulomas, and 5 controls) were analyzed. The type of inflammatory infiltrate was evaluated by hematoxylin-eosin staining, and the presence of mast cells was analyzed by toluidine blue staining. Indirect immunohistochemistry was used to evaluate the expression of cytokines, chemokines, and FoxP3. RESULTS The inflammatory infiltrate mainly consisted of mononuclear cells. In cysts, mononuclear infiltrates were significantly more frequent than mixed (polymorphonuclear/mononuclear) infiltrates (P = .04). Mixed inflammatory infiltrates were significantly more frequent in patients with sinus tract (P = .0001). The number of mast cells was significantly higher in granulomas than in cystic lesions (P = .02). A significant difference in the expression of IL-17 (P = .001) and TGF-beta (P = .003) was observed between cysts and granulomas and the control group. Significantly higher IL-17 levels were also observed in cases of patients with sinus tract (P = .03). CONCLUSIONS We observed that chronic periapical lesions might experience a reagudization process that is correlated with an increased leukocyte infiltration, with the predominance of neutrophils attracted by a chemokine milieu, as well as the increased presence of IL-17.

The Influence of Sex and Ovarian Hormones on Temporomandibular Joint Nociception in Rats

UNLABELLED The aim of this study was to investigate the influence of sex and ovarian hormones on formalin- and glutamate-induced temporomandibular joint (TMJ) nociception in rats. The influence of sex and ovarian hormones on the nociceptive behavior induced by formalin or glutamate was virtually the same. The nociceptive behavior of males was similar to that of females in the proestrus phase of the estrous cycle but was significantly lower than that in the diestrus phase. Since the serum level of estradiol but not of progesterone was significantly higher in the proestrus than in the diestrus phase, these data suggest that females with lower endogenous serum level of estradiol have an exacerbation of TMJ nociception. The nociceptive behavior of ovariectomized rats was similar to that of diestrus females and significantly greater than that of proestrus females. Although the administration of estradiol or progesterone in ovariectomized females significantly reduced TMJ nociception, the combination of both hormones did not increase the antinociceptive effect induced by each of them. These findings suggest that estradiol and progesterone decrease TMJ nociception in an independent way. PERSPECTIVE We report that ovarian hormones have an antinociceptive effect on the TMJ formalin and glutamate nociceptive behavior models. Therefore, the greater prevalence and severity of TMJ pain in women of reproductive age may be a consequence of hormonal fluctuation during the reproductive cycle, in that during low endogenous estradiol serum level TMJ pain sensitivity is increased, enhancing the risk of females experiencing TMJ pain.

15d-Prostaglandin J2 Inhibits Inflammatory Hypernociception: Involvement of Peripheral Opioid Receptor

The 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) is an endogenous ligand of peroxisome proliferator-activated receptors γ (PPAR-γ) and is now recognized as a potent anti-inflammatory mediator. However, information regarding the influence of 15d-PGJ2 on inflammatory pain is still unknown. In this study, we evaluated the effect of 15d-PGJ2 upon inflammatory hypernociception and the mechanisms involved in this effect. We observed that intraplantar administration of 15d-PGJ2 (30–300 ng/paw) inhibits the mechanical hypernociception induced by both carrageenan (100 μg/paw) and the directly acting hypernociceptive mediator, prostaglandin E2 (PGE2). Moreover, 15d-PGJ2 [100 ng/temporomandibular joint (TMJ)] inhibits formalin-induced TMJ hypernociception. On the other hand, the direct administration of 15d-PGJ2 into the dorsal root ganglion was ineffective in blocking PGE2-induced hypernociception. In addition, the 15d-PGJ2 antinociceptive effect was enhanced by the increase of macrophage population in paw tissue due to local injection of thioglycollate, suggesting the involvement of these cells on the 15d-PGJ2-antinociceptive effect. Moreover, the antinociceptive effect of 15d-PGJ2 was also blocked by naloxone and by the PPAR-γ antagonist 2-chloro-5-nitro-N-phenylbenzamide (GW9662), suggesting the involvement of peripheral opioids and PPAR-γ receptor in the process. Similar to opioids, the 15d-PGJ2 antinociceptive action depends on the nitric oxide/cGMP/protein kinase G \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \((\mathrm{PKG}){/}\mathrm{K}_{\mathrm{ATP}}^{+}\) \end{document} channel pathway because it was prevented by the pretreatment with the inhibitors of nitric-oxide synthase (NG-monomethyl-l-arginine acetate), guanylate cyclase]1H-(1,2,4)-oxadiazolo(4,2-α)quinoxalin-1-one[, PKG [indolo[2,3-a]pyrrolo[3,4-c]carbazole aglycone (KT5823)], or with the ATP-sensitive potassium channel blocker glibenclamide. Taken together, these results demonstrate for the first time that 15d-PGJ2 inhibits inflammatory hypernociception via PPAR-γ activation. This effect seems to be dependent on endogenous opioids and local macrophages.

Activation of peripheral κ/δ opioid receptors mediates 15-deoxy-Δ12,14-prostaglandin J2 induced-antinociception in rat temporomandibular joint

This study assessed the effect of the agonist 15d-PGJ(2) administered into the rat temporomandibular joint (TMJ) on nociceptive behavioral and the anti-inflammatory potential of this prostaglandin on TMJ. It was observed that 15-deoxy-(Delta12,14)-prostaglandin J(2) (15d-PGJ(2)) significantly reduced formalin-induced nociceptive behavior in a dose dependent manner, however injection of 15d-PGJ(2) into the contralateral TMJ failed to reduce such effects. This antinociceptive effect is dependent on peroxisome proliferator-activated receptors-gamma (PPAR-gamma) since pre-treatment with GW9662 (PPAR-gamma receptor antagonist) blocked the antinociceptive effect of 15d-PGJ(2) in the TMJ. In addition, the antinociceptive effect of 15d-PGJ(2) was also blocked by naloxone suggesting the involvement of peripheral opioids in the process. Confirming this hypothesis pre-treatment with kappa, delta, but not mu receptor antagonists significantly reduced the antinociceptive effect of 15d-PGJ(2) in the TMJ. Similarly to opioid agonists, the 15d-PGJ(2) antinociceptive action depends on the nitric oxide (NO)/guanilate cyclase (cGMP)/ATP-sensitive potassium channel blocker(K(+)(ATP)) channel pathway since it was prevented by the pre-treatment with the inhibitors of nitric oxide synthase (NOS; aminoguanidine), cGMP (ODQ), or the K(+)(ATP) (glibenclamide). In addition, 15d-PGJ(2) (100 ng/TMJ) inhibits 5-HT-induced TMJ hypernociception. Besides, TMJ treated with 15d-PGJ(2) showed lower vascular permeability, assessed by Evans Blue extravasation, and also lower neutrophil migration induced by carrageenan administration. Taken together, these results demonstrate that 15d-PGJ(2) has a potential peripheral antinociceptive and anti-inflammatory effect in the TMJ via PPAR-gamma activation. The results also suggest that 15d-PGJ(2) induced-peripheral antinociceptive response in the TMJ is mediated by kappa/delta opioid receptors by the activation of the intracellular l-arginine/NO/cGMP/K(+)(ATP) channel pathway. The pharmacological properties of the peripheral administration of 15d-PGJ(2) highlight the potential use of this PPAR-gamma agonist on TMJ inflammatory pain conditions.

Quercetin inhibits inflammatory bone resorption in a mouse periodontitis model.

Periodontitis is a disease that leads to bone destruction and represents the main cause of tooth loss in adults. The development of aggressive periodontitis has been associated with increased inflammatory response that is induced by the presence of a subgingival biofilm containing Aggregatibacter actinomycetemcomitans. The flavonoid quercetin (1) is widespread in vegetables and fruits and exhibits many biological properties for possible medical and clinical applications such as its anti-inflamatory and antioxidant effects. Thus, in the present study, the properties of 1 have been evaluated in bone loss and inflammation using a mouse periodontitis model induced by A. actinomycetemcomitans infection. Subcutaneous treatment with 1 reduced A. actinomycetemcomitans-induced bone loss and IL-1β, TNF-α, IL-17, RANKL, and ICAM-1 production in the gingival tissue without affecting bacterial counts. These results demonstrated that quercetin exhibits protective effects in A. actinomycetemcomitans-induced periodontitis in mice by modulating cytokine and ICAM-1 production.

Effect of gonadal steroid hormones on formalin-induced temporomandibular joint inflammation

We have recently demonstrated that gonadal steroid hormones decrease formalin‐induced temporomandibular joint nociception in rats. Given that the attenuation of inflammation is a potential mechanism underlying this antinociceptive effect, we evaluated the effect of gonadal steroid hormones on formalin‐induced temporomandibular joint inflammation. Plasma extravasation, a major sign of acute inflammation, and neutrophil migration, an important event related to tissue injury, were evaluated. Formalin induced significantly lower temporomandibular joint plasma extravasation and neutrophil migration in proestrus females than in males and in diestrus females. Since estradiol serum level is high in proestrus females and low in diestrus females and in males, these findings suggest that the high physiological level of estradiol decreases temporomandibular joint inflammation. Estradiol but not progesterone administration in ovariectomized females significantly decreased formalin‐induced plasma extravasation and neutrophil migration, an effect that was blocked by the estrogen receptor antagonist ICI 182780. Plasma extravasation and neutrophil migration were not affected by orchiectomy, but testosterone or estradiol administration in orchidectomized males significantly decreased them. The androgen receptor antagonist flutamide blocked the anti‐inflammatory effect of testosterone while ICI 182780 blocked that of estradiol in males. Previous intravenous administration of a nonspecific selectin inhibitor significantly decreased formalin‐induced temporomandibular joint nociception and neutrophil migration in males, revealing a potent and positive correlation between temporomandibular joint nociception and inflammation. Taken together, these findings demonstrate a pronounced anti‐inflammatory effect of estradiol and testosterone in the temporomandibular joint region and suggest that this effect may mediate, at least in part, the antinociceptive effect of these hormones.

Gonadal hormones decrease temporomandibular joint κ-mediated antinociception through a down-regulation in the expression of kappa opioid receptors in the trigeminal ganglia

We have previously demonstrated that activation of kappa-opioid receptor located in the temporomandibular joint (TMJ) of rats induces a significantly greater TMJ antinociception in diestrus females than in proestrus females (higher estradiol serum levels than diestrus) and males. These findings indicate that gonadal hormones decrease TMJ kappa-mediated antinociception. The aim of this study was to investigate some of the mechanisms by which gonadal hormones decrease TMJ kappa-mediated antinociception. Western blot analysis demonstrated a significantly lower kappa-opioid receptor expression in the trigeminal ganglia of intact males than in intact and ovariechtomized (OVX) females and orchidectomized (ORX) males. In females, kappa-opioid receptor expression in the trigeminal ganglia was significantly lower in proestrus than in diestrus and OVX females. Taken together these findings suggest that gonadal hormones, especially male gonadal hormones, down-regulate kappa-opioid receptor expression. Co-application of the NOS inhibitor L-NMMA or the NO-sensitive guanylyl cyclase inhibitor ODQ with the kappa-opioid receptor agonist U50,488 blocked TMJ kappa-mediated antinociception in males and females. These findings suggest that antinociception induced by activation of kappa opioid receptors in the TMJ region is mediated by the L-arginine/NO/cGMP pathway in both sexes. Despite the involvement of the L-arginine/NO/cGMP pathway in TMJ kappa-mediated antinociception in both sexes, gonadal hormones do not diminish the activity of this pathway to decrease TMJ kappa-mediated antinociception. Alternatively, they significantly reduce kappa-opioid receptor expression in the trigeminal ganglia.

Local kappa opioid receptor activation decreases temporomandibular joint inflammation.

In an attempt to decrease central side effects associated with the use of opioids, some strategies have been developed by targeting peripheral opioid receptors. In this context, kappa receptors are of major interest, since, in contrast to other opioid receptors, their activation is not associated with potent peripheral side effects. We have recently demonstrated that local activation of kappa opioid receptors significantly decreases formalin-induced temporomandibular joint nociception; however, whether it also decreases temporomandibular joint inflammation is not known. To address this issue, we evaluated if a specific kappa opioid receptor agonist, U50,488 (trans-(1S,2S)-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl)cyclohexyl] benzeneacetamide hydrochloride hydrate), administered into the temporomandibular joint decreases formalin-induced plasma extravasation and neutrophil migration. Ipsilateral, but not contralateral, administration of U50,488 into the temporomandibular joint blocked formalin-induced plasma extravasation and neutrophil migration in a dose-dependent manner. This anti-inflammatory effect was reversed by the ipsilateral, but not contralateral, administration of the kappa opioid receptor antagonist nor-BNI (nor-binaltorphimine dihydrochloride). This study demonstrates that local activation of kappa opioid receptors decreases two important parameters of temporomandibular joint inflammation, that is, plasma extravasation and neutrophil migration, in a dose-dependent and antagonist-reversible manner. This anti-inflammatory effect taken together with the potent antinociceptive effect, suggests that drugs targeting peripheral kappa opioid receptors are promising for the treatment of inflammatory temporomandibular joint pain and probably, other articular pain conditions with an inflammatory basis.

Secreted osteoclastogenic factor of activated T cells (SOFAT), a novel osteoclast activator, in chronic periodontitis

A novel activated human T cell-secreted cytokine, referred as secreted osteoclastogenic factor of activated T cells (SOFAT), that induce osteoclastogenesis in a RANKL-independent manner was recently described. This study evaluated the role of SOFAT in periodontal tissues and periodontitis. Gingival biopsies were harvested from systemically healthy non-periodontitis (n=15) and chronic periodontitis patients (n=15). The mRNA and protein levels of SOFAT were measured by qPCR and by enzyme-linked immunosorbent assay, respectively. Moreover, RAW 264.7 cells were cultured with SOFAT or Receptor activator of nuclear factor-kB ligand (RANKL) and stained for tartrate-resistant acid phosphatase (TRAP). Also, mice received a palatal injection between the first and second upper molar of SOFAT (100 ng/ml) or saline solution (0.9%). The upper jaw was removed, histologically processed and stained with hematoxilin and eosin to observe the presence of osteoclast-like cells. The mRNA and protein levels of SOFAT were significantly higher in the gingival tissue of the periodontitis group when compared to non-periodontitis one (p<0.05). In addition, SOFAT potently induced TRAP-positive multinucleated cell formation by RAW 264.7 cells as well as induced the formation of osteoclast-like cells in the periodontal ligament in mice. The present study demonstrated that SOFAT may play an important role in periodontitis.

Antinoceptive and Anti-inflammatory Activities of the Ethanolic Extract, Fractions and Flavones Isolated from Mimosa tenuiflora (Willd.) Poir (Leguminosae)

The bark of Mimosa tenuiflora (Willd.) Poiret (Leguminosae family), popularly known as “jurema preta” in Brazil, is used by the population of Contendas of Sincorá (Bahia State, Brazil) for the treatment of coughs and wound healing. Thus, the aim of this study was to evaluate the antinociceptive and anti-inflammatory activities of the bark ethanol extract (EEMT) and solvent soluble fractions (hexane—H, DCM—D, EtOAc—E and BuOH—B) of the extract in vivo. Additionally, we synthesized 5,7-dihidroxy-4’-methoxyflavanone (isosakuranetin) and isolated the compound sakuranetin, and both compounds were also tested. The anti-inflammatory and antinociceptive assays performed were: writhing test; nociception induced by intraplantar formalin injection; leukocyte recruitment to the peritoneal cavity; evaluation of vascular permeability (Evans blue test); and evaluation of mechanical hypernociception (von Frey test). Production of TNF-α, IL-10, myeloperoxidase and the expression of ICAM-1 were also evaluated. Statistical analysis was performed by one-way ANOVA followed by the Bonferroni post-test (n = 8), with P < 0.05. The EEMT showed antinociceptive activities in writhing test (100–200 mg/kg), in the second phase of the formalin test (50–200 mg/kg), and in mechanical hypernociception (100 mg/kg). EEMT showed an anti-inflammatory effect by reducing neutrophil migration to the peritoneal cavity and in the plantar tissue detected by the reduction of myeloperoxidase activity (100 mg/kg), reduction of IL-10 levels and expression of ICAM-1 in the peritoneal exudate and the mesentery (100 mg/kg), respectively. The four soluble EEMT fractions showed good results in tests for antinociceptive (H, D, E, B) and anti-inflammation (H, D, E). Only sakuranetin showed reduction of the writhing and neutrophil migration (200 mg/kg). Thus, the EEMT and soluble fractions of M. tenuiflora bark demonstrated great antinociceptive and anti-inflammatory activities, as also sakuranetin. More studies should be conducted to elucidate the mechanism of action of this compound. To the best of our knowledge, this is the first report on the antinociceptive activity of the M. tenuiflora fractions and the bioactive isolated compound sakuranetin in vivo.