Submitted by Angela Maria de Oliveira (amolivei@uepg.br) on 2017-10-19T16:57:47Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Ana Paula Prestes.pdf: 3605204 bytes, checksum: c04bdcd5fbd85e3c01286278cea6ad0c (MD5) / Made available in DSpace on 2017-10-19T16:57:48Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Ana Paula Prestes.pdf: 3605204 bytes, checksum: c04bdcd5fbd85e3c01286278cea6ad0c (MD5) Previous issue date: 2016-03-30 / Processos inflamatórios estão associados ao aumento dos níveis plasmáticos de bradicinina (BK) e de seus metabólitos des-Arg9-bradicinina (DABK) e des-Arg10-Lysbradicinina. A ação das cininas é mediada pela ativação dos receptores B1 e B2. A BK age preferencialmente a partir da estimulação dos receptores B2 constitutivos. Em contrapartida, os metabólitos da BK atuam nos receptores B1 que são expressos somente em tecidos que sofreram trauma prévio ou infecção. Estudos propõem que a ação dos receptores B1 esteja correlacionada a processos inflamatórios crônicos tais como a periodontite. Desta maneira, o propósito deste trabalho foi investigar a participação dos receptores B1 e B2 para cininas na inflamação sistêmica e nas alterações cardiovasculares induzidas pela periodontite em ratos. Quatorze dias após a colocação de ligaduras para a indução da periodontite ou realização do procedimento de falso-operado, os animais foram submetidos ao experimento de edema de pata para diferentes agentes flogísticos – carragenina, BK, DABK, serotonina, histamina e prostaglandina E2. Além da avaliação edematogênica, a migração de células polimorfonucleares e a permeabilidade vascular no tecido da pata foram avaliadas após a indução do edema de pata mediado por carragenina. No mesmo intervalo de tempo realizou-se a avaliação das alterações na pressão arterial média para os agonistas dos receptores B1 e B2. Os níveis plasmáticos e teciduais (tecido da pata) de TNF-α e IL-β foram quantificados após três, sete e quatorze dias da indução da periodontite. A quantificação protéica do receptor B1 para cininas foi realizada 14 dias após a indução da periodontite. Os resultados obtidos para o procedimento de edema de pata mediado por carragenina demonstraram um aumento estatisticamente significativo no edema, na migração de células polimorfonucleares e na permeabilidade vascular nos animais do grupo ligadura. Nenhuma diferença entre os grupos ligadura e falso-operado foram observadas no edema de pata induzido por serotonina, histamina e prostaglandina E2. Nenhuma diferença entre os grupos ligadura e falso-operado foram observadas no edema de pata induzido por BK. Intessantemente, o grupo ligadura apresentou um aumento estatisticamente significativo no edema de pata induzido por DABK. Dessa maneira, o edema induzido por DABK caracterizou a participação dos receptores B1 no edema de pata no grupo ligadura, mas não foi observada uma alteração na quantificação protéica deste receptor entre os grupos experimentais. As alterações na pressão arterial média induzidas pelos agonistas da BK e DABK foram similares. Os níveis plasmáticos de TNF-α foram superiores no grupo ligadura após 3 dias da indução da periodontite. Em contrapartida, os níveis teciduais de IL-1β foram superiores no grupo ligadura. Os dados obtidos sugerem que a periodontite pode promover alterações na resposta inflamatória em tecidos distantes da cavidade oral. Dessa maneira, as alterações nos parâmetros inflamatórios podem alterar a ativação dos receptores B1 e esses receptores contribuírem nas alterações inflamatórias sistêmicas induzidas pela periodontite. / The inflammatory process is associated with increased plasma levels of bradykinin (BK) and its metabolites des-Arg9-bradykinin (DABK) and des-Arg10-lys-bradykinin. The kinins effects are mediated through B1 and B2 receptors activation. BK acts preferentially in the constitutive B2 receptors. In contrast, BK metabolites act in the B1 receptors that are expressed only in tissues that have undergone previous trauma or infection. Studies suggest that the action of the B1 receptor is correlated to chronic inflammatory processes such as periodontitis. Thus, the purpose of this study was to investigate the involvement of B1 and B2 kinin receptors in systemic inflammation and cardiovascular changes induced by periodontitis in rats. Fourteen days after the induction of periodontitis by ligature placement or sham procedure, animals were underwent to the paw edema procedure induced for different phogistic agents – carragenan, BK, DABK, serotonin and prostaglandin E2. In addition to the paw edema procedure the migration of polymorphonuclear cells and vascular permeability changes were evaluated after carrageenan-induced paw edema. In the same period of time the assessment of changes in mean arterial pressure for B1 and B2 receptors agonists were determinate. The plasma and tissue levels (paw tissue) of TNF-α and IL-1β were quantified after three, seven and fourteen days of periodontitis induction. The protein quantification (western-blotting) of B1 receptor was determinate after fourteen days of periodontitis induction. The results obtained for paw edema procedure mediated by carrageenan demonstrated a statistically significant increase in the edema, polymorphonuclear cells migration and vascular permeability in the ligature group. No differences between the ligature and sham group were observed in paw edema induced by serotonin, histamine and prostaglandin E2. No differences between the ligature and sham group were observed in BK-induced paw edema. Interestingly, the DABK-induced paw edema was increased at ligature group. Therefore the increase at edema induced by DABK-indicate the activation of the B1 receptors in the paw edema in ligature group, but changes in protein quantification of B1 receptor were not observed between experimental groups. The changes in blood pressure induced by BK and DABK agonist were similar. The plasma levels of TNF-α were higher in the ligature group after three days of periodontitis induction. In contrast, tissue levels of IL-1β were higher in the ligature group. The data suggest that periodontitis can promote changes in inflammatory response in tissues distant from oral cavity. Thus, alterations in inflammatory parameters can increase the expression of B1 receptors, and these receptors may contribute in the systemic inflammatory changes induced by periodontitis.

Inflammatory processes in, or in close vicinity of, the skeleton often lead to loss of bone tissue. Different cytokines have been shown to be involved as stimulators of inflammatory induced osteoclastic bone resorption. During inflammatory processes also the kallikrein-kinin system is activated, leading to production of kinins that can cause pain, vasodilation and increased permeability of vessels. Kinins can also induce bone resorption in vitro. All cytokines and kinins that stimulate bone resorption stimulate in parallell prostaglandin synthesis, and prostaglandins, per se, have also been shown to induce bone resorption. The aim of this project was to increase the knowledge about the mechanisms involved in the interactions between different inflammatory mediators (i.e. kinins, cytokines and prostaglandins) suggested to be involved in the pathogenesis of inflammatory bone resorbing diseases. Human osteoblasts (MG-63) are equipped with both kinin B1 and B2 receptors linked to prostaglandin release and the stimulation of prostaglandin release are likely mediated via separate molecular mechanisms (Paper I). Activation of B1 or B2 receptors causes synergistic stimulation of PGE2 synthesis induced by either interleukin-1b (IL-1b) or tumour necrosis factor-a (TNF-a) (Paper II). The molecular mechanism involves increased expression of cyclooxygenase-2 (COX-2) and results in synergistic potentiation of receptor activator of NF-kB ligand (RANKL) protein expression. The synergistic interaction is dependent on the activation of NF-kB and the mitogen-activated protein kinases (MAPK) p38 and JNK (Paper II). The synergistic increase in RANKL expression might be an explanation why kinins potentiate IL-1b induced bone resorption, a mechanism likely to be important in inflammation induced bone resorption in diseases such as periodontal disease and rheumatoid arthritis. The synergism between kinins and IL-1b or TNF-a might also be dependent on regulation of kinin receptors, since both IL-1b and TNF-a markedly upregulated B1 and B2 receptors, both at the mRNA level and protein level (Paper III). This upregulation is not further potentiated by the kinins, and different kinin receptor agonists do not regulate the receptors for IL-1b or TNF-a, in MG-63 cells. No other cytokines known to stimulate bone resorption regulates the expressions of B1 and B2 receptors. The IL-1b- or TNF-a-induced enhancements of B1 and B2 receptor expressions involve activation of NF-kB and MAPK. The enhancement of kinin receptors may also be an important mechanism in the synergistic interactions between the two pro-inflammatory cytokines and kinins (paper III). IL-4 and IL-13 are two cytokines that have been shown to inhibit bone resorption. We have shown that COX-2 and both B1 and B2 receptors are down-regulated by IL-4 and IL-13, via a ‘signal transducer and activator of transcription6’ (STAT6) dependent pathway, which might be an important regulatory mechanism in inflammation induced bone resorption (paper IV). In conclusion, the mechanisms behind the synergistic potentiation of prostaglandin formation and increased bone resorption caused by co-stimulation with kinins and IL-1b or TNF-a seem to involve both potentiation of COX-2 and subsequently increased levels of RANKL, as well as upregulation of B1 and B2 kinin receptors. Interestingly, IL-4 and IL-13 decreased the expressions of COX-2 and both B1 and B2 receptors. These events might be important in the regulation of inflammation induced bone resorption in diseases such as periodontitis and rheumatoid arthritis.