INTRODUÇÃO: Líquen plano pilar (LPP) e alopecia frontal fibrosante (AFF) são alopecias cicatriciais linfocíticas crônicas, caracterizadas pela destruição permanente da unidade pilossebácea. Neuropeptídeos como a substância P (SP) e o peptídeo relacionado ao gene da calcitonina (CGRP) têm sido implicados no metabolismo lipídico das glândulas sebáceas e na manutenção do estado inflamatório de diversas doenças. OBJETIVOS: 1. Quantificar e comparar a expressão dos neuropeptídeos SP e CGRP em amostras do couro cabeludo (áreas afetadas e aparentemente não afetadas) e séricas de pacientes com LPP e AFF, em relação a indivíduos sadios, utilizando a técnica de ELISA. 2. Analisar áreas afetadas e aparentemente não afetadas de pacientes com LPP e AFF através da imunofluorescência direta (IFD). MÉTODO: 20 pacientes (10 com LPP e 10 com AFF) e 11 indivíduos sadios foram submetidos a biópsias com punch de 4mm do couro cabeludo e coleta de amostras sanguíneas. Pacientes foram submetidos a biópsias das áreas afetadas e aparentemente não afetadas do couro cabeludo, as quais foram pareadas com amostras da região anterior e posterior do couro cabeludo dos indivíduos-controle. As amostras dos pacientes foram enviadas para análise histopatológica, IFD e teste de ELISA para SP e CGRP. As amostras dos controles foram submetidas à análise histopatológica e aos mesmos testes de ELISA. Sintomas (dor, prurido, queimação e formigamento) e sinais inflamatórios (eritema difuso, eritema peripilar e descamação peripilar) na região afetada dos pacientes também foram avaliados. Este estudo foi realizado nas Universidades de São Paulo (BRA) e de Minnesota (EUA), entre os anos de 2012 e 2014. RESULTADOS: A análise histopatológica evidenciou infiltrado perifolicular linfocítico típico em 70% das áreas aparentemente não afetadas do couro cabeludo de pacientes com LPP e AFF, além de fibrose e depósitos de mucina perifoliculares. Em relação à IFD, o resultado se mostrou positivo em 50% das amostras das áreas afetadas e em 40% das áreas aparentemente não afetadas dos pacientes com LPP, em comparação a 40% e 20% nos casos de AFF, respectivamente. No teste de ELISA, pacientes do grupo LPP e infiltrado histopatológico de moderado a intenso na área afetada, demonstraram maior expressão de SP na área afetada, em comparação àquela aparentemente não afetada (P=0,046). Já pacientes do grupo AFF com o mesmo grau histopatológico de inflamação, demonstraram maior expressão de SP na área aparentemente não afetada, em comparação à área afetada (P=0,050). No teste de ELISA para CGRP, pacientes com LPP e inflamação histopatológica de leve a ausente na área afetada, tiveram maior expressão deste neuropeptídeo na área aparentemente não afetada, em comparação à área afetada (P=0,048). Por outro lado, pacientes com AFF que tinham o mesmo grau de inflamação histopatológica, a expressão deste neuropeptídeo foi favorecida na área afetada, em relação àquela aparentemente não afetada (P=0,050). Todas as amostras séricas dos pacientes e controles e do couro cabeludo dos indivíduos-controle tiveram resultados indetectáveis para SP e CGRP no teste de ELISA. Nenhuma relação entre sinais e sintomas inflamatórios e expressão de SP e CGRP no teste de ELISA foi vista. CONCLUSÃO: O acometimento das áreas aparentemente não afetadas do couro cabeludo de pacientes com LPP e AFF ao exame histopatológico, sugere que ambas as doenças possam acometer de forma difusa esta região. Apesar da semelhança dos achados histopatológicos entre pacientes com LPP e AFF, resultados antagônicos dos neuropeptídeos encontrados no teste de ELISA apontam para mecanismos fisiopatogênicos distintos. A inflamação neurogênica poderia explicar a sintomatologia e contribuir para a patogênese destas doenças / INTRODUCTION: Lichen planopilaris (LPP) and frontal fibrosing alopecia (FFA) are primary lymphocytic cicatricial alopecias characterized by permanent destruction of the pilossebaceous unit. Neuropeptides such as substance P (SP) and calcitonin gene-related peptide (CGRP) are related to lipid metabolism in sebaceous glands and to the maintenance of many inflammatory chronic disorders. OBJECTIVES: 1. Quantify SP and CGRP expression in affected and in normal-appearing scalp areas and serum samples from patients with LPP and FFA, and compare to healthy controls using ELISA technique. 2. Compare affected and normal-appearing areas from patients with LPP and FFA, using direct immunofluoresce (DIF) technique. METHODS: Twenty patients (10 with LPP and 10 with FFA) and eleven healthy controls underwent 4mm-punch biopsies and blood extraction. Patients collected samples from affected and normal-appearing scalp areas, and controls collected from anterior and posterior scalp areas. Patients samples were sent to histopathologic examination, DIF and ELISA tests for SP and CGRP detection. Control samples were sent to histopathologic examination and to the same ELISA tests. Symptoms (pain, burning, itching and tingling) and signs of inflammation (diffuse erythema, perifollicular erythema and perifollicular scale) were also assessed. This study was done at the Universities of São Paulo (Brazil) and Minnesota (USA), between 2012 and 2014. RESULTS: Normal-appearing scalp areas from patients with LPP and FFA showed lymphocytic perifollicular typical inflammation in 70% of the cases, as well as perifollicular fibrosis and mucin deposits. DIF test was positive in 50% of the affected areas and in 40% of normalappearing areas from patients with LPP, comparing to 40% and 20% in the FFA group, respectively. In SP ELISA test, affected areas from patients with LPP that had histopathologic moderate or intense infiltrate showed more expression of SP in the affected scalp, comparing to normal-appearing areas (P=0,046). However, affected areas from patients with FFA that showed the same degree of histopathologic infiltrate had higher expression of SP in normalappearing scalp, comparing to affected scalp (P=0.050). In CGRP ELISA test, affected scalp from patients with LPP that had histopathologic mild or irrelevant infiltrate showed increased CGRP expression in normal-appearing scalp areas, comparing to affected scalp (P=0,048). Althought, affected areas with the same degree of histopathologic inflammation from patients with FFA had more CGRP, comparing to normal-appearing scalp (P=0,050). All serum samples and scalp samples from controls had undetectable results in SP and CGRP ELISA tests. No clinical relationship was found among symptoms, signs of inflammation, and neuropeptide expression. CONCLUSION: Normal-appearing scalp areas can show histopathologic inflammation suggesting that both LPP and FFA can be more generalized processes affecting the scalp. Although both diseases share similar histopathologic findings, the opposite results in the ELISA test point that these diseases may have diverse pathogenic mechanisms. Neurogenic inflammation possibly play an important role in the pathogenesis of both LPP and FFA and may explain the symptomatic scalp some patients refer

<p>Anabolic-androgenic steroids (AAS) have been used in clinics for decades. The misuse of AAS has previously been attributed merely to sport athletes, taking AAS with intentions to increase muscle mass, enhance physical performance and to improve results in competitions. Today, the misuse of AAS has spread to adolescents and young adults not connected to sports. Alarmingly, many reports are pointing at severe psychiatric adverse effects among AAS abusers, which include mood swings, mania, anxiety, depression and aggression. Numerous examples of severe and often unprovoked violence and brutal crimes have been connected to AAS abuse and there is a strong need for a better understanding of the underlying biochemical events that might account for the adverse behaviors induced by AAS. The general aim of this thesis was to study the effect of chronic AAS administration on neuropeptide circuits in the rat brain associated with the regulation of rewarding effects, memory, anxiety, depression and aggression, using nandrolone decanoate as a prototype AAS.</p><p>Results demonstrated that daily administration of AAS to rats in doses comparable to those taken by AAS abusers, in certain brain structures significantly affected, <i>a</i>) the levels of the opioid peptides dynorphin B and Met-enkephalin-Arg⁶Phe⁷, <i>b</i>) the levels of the tachykinin substance P (SP), <i>c</i>) the density of the SP neurokinin 1 (NK1) receptor, <i>d</i>) the level of the SP metabolite SP_1-7that frequently exerts opposite effects to SP, <i>e</i>) the SP_1-7generating enzyme substance P endopeptidase (SPE) and finally, <i>f</i>) the levels of the neuropeptide calcitonin gene-related peptide (CGRP) often co-localized with SP. The alterations seen in the levels and activities of these neurochemical components are in many aspects compatible with behaviors typified among AAS abusers.</p>

Anabolic-androgenic steroids (AAS) have been used in clinics for decades. The misuse of AAS has previously been attributed merely to sport athletes, taking AAS with intentions to increase muscle mass, enhance physical performance and to improve results in competitions. Today, the misuse of AAS has spread to adolescents and young adults not connected to sports. Alarmingly, many reports are pointing at severe psychiatric adverse effects among AAS abusers, which include mood swings, mania, anxiety, depression and aggression. Numerous examples of severe and often unprovoked violence and brutal crimes have been connected to AAS abuse and there is a strong need for a better understanding of the underlying biochemical events that might account for the adverse behaviors induced by AAS. The general aim of this thesis was to study the effect of chronic AAS administration on neuropeptide circuits in the rat brain associated with the regulation of rewarding effects, memory, anxiety, depression and aggression, using nandrolone decanoate as a prototype AAS. Results demonstrated that daily administration of AAS to rats in doses comparable to those taken by AAS abusers, in certain brain structures significantly affected, a) the levels of the opioid peptides dynorphin B and Met-enkephalin-Arg6Phe7, b) the levels of the tachykinin substance P (SP), c) the density of the SP neurokinin 1 (NK1) receptor, d) the level of the SP metabolite SP1-7 that frequently exerts opposite effects to SP, e) the SP1-7 generating enzyme substance P endopeptidase (SPE) and finally, f) the levels of the neuropeptide calcitonin gene-related peptide (CGRP) often co-localized with SP. The alterations seen in the levels and activities of these neurochemical components are in many aspects compatible with behaviors typified among AAS abusers.

INTRODUÇÃO: Líquen plano pilar (LPP) e alopecia frontal fibrosante (AFF) são alopecias cicatriciais linfocíticas crônicas, caracterizadas pela destruição permanente da unidade pilossebácea. Neuropeptídeos como a substância P (SP) e o peptídeo relacionado ao gene da calcitonina (CGRP) têm sido implicados no metabolismo lipídico das glândulas sebáceas e na manutenção do estado inflamatório de diversas doenças. OBJETIVOS: 1. Quantificar e comparar a expressão dos neuropeptídeos SP e CGRP em amostras do couro cabeludo (áreas afetadas e aparentemente não afetadas) e séricas de pacientes com LPP e AFF, em relação a indivíduos sadios, utilizando a técnica de ELISA. 2. Analisar áreas afetadas e aparentemente não afetadas de pacientes com LPP e AFF através da imunofluorescência direta (IFD). MÉTODO: 20 pacientes (10 com LPP e 10 com AFF) e 11 indivíduos sadios foram submetidos a biópsias com punch de 4mm do couro cabeludo e coleta de amostras sanguíneas. Pacientes foram submetidos a biópsias das áreas afetadas e aparentemente não afetadas do couro cabeludo, as quais foram pareadas com amostras da região anterior e posterior do couro cabeludo dos indivíduos-controle. As amostras dos pacientes foram enviadas para análise histopatológica, IFD e teste de ELISA para SP e CGRP. As amostras dos controles foram submetidas à análise histopatológica e aos mesmos testes de ELISA. Sintomas (dor, prurido, queimação e formigamento) e sinais inflamatórios (eritema difuso, eritema peripilar e descamação peripilar) na região afetada dos pacientes também foram avaliados. Este estudo foi realizado nas Universidades de São Paulo (BRA) e de Minnesota (EUA), entre os anos de 2012 e 2014. RESULTADOS: A análise histopatológica evidenciou infiltrado perifolicular linfocítico típico em 70% das áreas aparentemente não afetadas do couro cabeludo de pacientes com LPP e AFF, além de fibrose e depósitos de mucina perifoliculares. Em relação à IFD, o resultado se mostrou positivo em 50% das amostras das áreas afetadas e em 40% das áreas aparentemente não afetadas dos pacientes com LPP, em comparação a 40% e 20% nos casos de AFF, respectivamente. No teste de ELISA, pacientes do grupo LPP e infiltrado histopatológico de moderado a intenso na área afetada, demonstraram maior expressão de SP na área afetada, em comparação àquela aparentemente não afetada (P=0,046). Já pacientes do grupo AFF com o mesmo grau histopatológico de inflamação, demonstraram maior expressão de SP na área aparentemente não afetada, em comparação à área afetada (P=0,050). No teste de ELISA para CGRP, pacientes com LPP e inflamação histopatológica de leve a ausente na área afetada, tiveram maior expressão deste neuropeptídeo na área aparentemente não afetada, em comparação à área afetada (P=0,048). Por outro lado, pacientes com AFF que tinham o mesmo grau de inflamação histopatológica, a expressão deste neuropeptídeo foi favorecida na área afetada, em relação àquela aparentemente não afetada (P=0,050). Todas as amostras séricas dos pacientes e controles e do couro cabeludo dos indivíduos-controle tiveram resultados indetectáveis para SP e CGRP no teste de ELISA. Nenhuma relação entre sinais e sintomas inflamatórios e expressão de SP e CGRP no teste de ELISA foi vista. CONCLUSÃO: O acometimento das áreas aparentemente não afetadas do couro cabeludo de pacientes com LPP e AFF ao exame histopatológico, sugere que ambas as doenças possam acometer de forma difusa esta região. Apesar da semelhança dos achados histopatológicos entre pacientes com LPP e AFF, resultados antagônicos dos neuropeptídeos encontrados no teste de ELISA apontam para mecanismos fisiopatogênicos distintos. A inflamação neurogênica poderia explicar a sintomatologia e contribuir para a patogênese destas doenças / INTRODUCTION: Lichen planopilaris (LPP) and frontal fibrosing alopecia (FFA) are primary lymphocytic cicatricial alopecias characterized by permanent destruction of the pilossebaceous unit. Neuropeptides such as substance P (SP) and calcitonin gene-related peptide (CGRP) are related to lipid metabolism in sebaceous glands and to the maintenance of many inflammatory chronic disorders. OBJECTIVES: 1. Quantify SP and CGRP expression in affected and in normal-appearing scalp areas and serum samples from patients with LPP and FFA, and compare to healthy controls using ELISA technique. 2. Compare affected and normal-appearing areas from patients with LPP and FFA, using direct immunofluoresce (DIF) technique. METHODS: Twenty patients (10 with LPP and 10 with FFA) and eleven healthy controls underwent 4mm-punch biopsies and blood extraction. Patients collected samples from affected and normal-appearing scalp areas, and controls collected from anterior and posterior scalp areas. Patients samples were sent to histopathologic examination, DIF and ELISA tests for SP and CGRP detection. Control samples were sent to histopathologic examination and to the same ELISA tests. Symptoms (pain, burning, itching and tingling) and signs of inflammation (diffuse erythema, perifollicular erythema and perifollicular scale) were also assessed. This study was done at the Universities of São Paulo (Brazil) and Minnesota (USA), between 2012 and 2014. RESULTS: Normal-appearing scalp areas from patients with LPP and FFA showed lymphocytic perifollicular typical inflammation in 70% of the cases, as well as perifollicular fibrosis and mucin deposits. DIF test was positive in 50% of the affected areas and in 40% of normalappearing areas from patients with LPP, comparing to 40% and 20% in the FFA group, respectively. In SP ELISA test, affected areas from patients with LPP that had histopathologic moderate or intense infiltrate showed more expression of SP in the affected scalp, comparing to normal-appearing areas (P=0,046). However, affected areas from patients with FFA that showed the same degree of histopathologic infiltrate had higher expression of SP in normalappearing scalp, comparing to affected scalp (P=0.050). In CGRP ELISA test, affected scalp from patients with LPP that had histopathologic mild or irrelevant infiltrate showed increased CGRP expression in normal-appearing scalp areas, comparing to affected scalp (P=0,048). Althought, affected areas with the same degree of histopathologic inflammation from patients with FFA had more CGRP, comparing to normal-appearing scalp (P=0,050). All serum samples and scalp samples from controls had undetectable results in SP and CGRP ELISA tests. No clinical relationship was found among symptoms, signs of inflammation, and neuropeptide expression. CONCLUSION: Normal-appearing scalp areas can show histopathologic inflammation suggesting that both LPP and FFA can be more generalized processes affecting the scalp. Although both diseases share similar histopathologic findings, the opposite results in the ELISA test point that these diseases may have diverse pathogenic mechanisms. Neurogenic inflammation possibly play an important role in the pathogenesis of both LPP and FFA and may explain the symptomatic scalp some patients refer

Microtubule targeting agents (MTAs) are chemotherapeutics commonly used in the treatment of breast, ovarian, lung, and lymphoma cancers. There are two main classes of MTAs based upon their effects on microtubule stability. The two classes are the destabilizing agents, which include the drug vincristine, and the stabilizing agents, which include paclitaxel and epothilone B. These drugs are highly effective antineoplastics, but their use is often accompanied by several side effects, one of which is peripheral neuropathy. Peripheral neuropathy can be characterized by burning pain, tingling, loss of proprioception, or numbness in the hands and feet. In some patients, the MTA-induced peripheral neuropathy is debilitating and dose-limiting; however, there are no effective prevention strategies or treatment options for peripheral neuropathy as the mechanisms mediating this side effect are unknown. The goal of this work was to investigate MTA-induced effects on neuronal activity and morphology in order to elucidate the underlying mechanisms involved in the development of MTA-induced peripheral neuropathy. As an indicator of sensory neuronal activity, the basal and stimulated release of the putative nociceptive peptide, calcitonin gene-related peptide (CGRP), was measured from sensory neurons in culture after exposure to the MTAs paclitaxel, epothilone B, and vincristine. Neurite length and branching were also measured in sensory neuronal cultures after treatment with these MTAs. The results described in this thesis demonstrate that MTAs alter the stimulated release of CGRP from sensory neurons in differential ways depending on the MTA agent employed, the CGRP evoking-stimulus used, the concentration of the MTA agent, the duration of exposure to the MTA agent, and the presence of NGF. It was also observed that MTA agents decrease neurite length and branching, independent of the concentration of NGF in the culture media. Thus, this thesis describes MTA-induced alterations of sensory neuronal sensitivity and neurite morphology and begins to elucidate the underlying mechanisms involved in MTA-induced alterations of sensory neurons. These findings will undoubtedly be used to help elucidate the mechanisms underlying MTA-induced peripheral neuropathy.

Les récepteurs couplés aux protéines G (RCPGs) constituent la plus grande classe de récepteurs membranaires impliqués dans la transmission des signaux extracellulaires. Traditionnellement, la transmission de la signalisation par les RCPGs implique l’activation d’une protéine G hétéro-trimérique qui pourra à son tour moduler l’activité de divers effecteurs intracellulaires. Ce schéma classique de signalisation s’est complexifié au fils des années et l’on sait maintenant qu’en plus d’interagir avec les protéines G, les RCPGs s’associent avec une panoplie d’autres protéines afin de transmettre adéquatement les signaux extracellulaires. En particulier, la découverte d’une famille de protéines transmembranaires modulant la fonction des RCPGs, baptisées protéines modifiant l’activité des récepteurs (« receptor activity-modifying proteins » ; RAMPs), a changé la façon de concevoir la signalisation par certains RCPGs. Dans le cas du récepteur similaire au récepteur de la calcitonine (« calcitonin-like receptor » ; CLR), l’association avec les RAMPs permet l’acheminement à la surface cellulaire du récepteur tout en modulant ses propriétés pharmacologiques. Lorsqu’il est associé avec RAMP1, le CLR fonctionne comme un récepteur du peptide relié au gène de la calcitonine (« calcitonin gene-related peptide » ; CGRP), alors qu’il devient un récepteur de l’adrénomedulline lorsqu’il interagit avec RAMP2 ou RAMP3. D’autre part, en plus d’interagir avec des protéines accessoires transmembranaires telles les RAMPs, les RCPGs peuvent aussi s’associer entre eux pour former des oligomères de récepteurs. Dans cette thèse, nous nous sommes penchés sur les interactions entre les RCPGs et les RAMPs, et plus particulièrement sur l’interrelation entre ce type d’association RCPG/RAMP et l’assemblage en oligomères de récepteurs, en utilisant le récepteur du CGRP comme modèle d’étude. Une première étude nous a tout d’abord permis de confirmer l’interaction entre le récepteur CLR et RAMP1, dans un contexte de cellules vivantes. Nous avons démontré que ce complexe CLR/RAMP1 active la protéine G et recrute la protéine de signalisation -arrestine suite à une stimulation par le CGRP. Ensuite, nous avons déterminé que même s’il doit obligatoirement former un hétéro-oligomère avec les RAMPs pour être actif, le CLR conserve malgré tout sa capacité à interagir avec d’autres RCPGs. En plus d’observer la présence d’homo-oligomère de CLR, nous avons constaté que tout comme les RCPGs, les RAMPs peuvent eux-aussi s’associer entre eux pour former des complexes oligomériques pouvant comprendre différents sous-types (RAMP1/RAMP2 et RAMP1/RAMP3). Cette observation de la présence d’homo-oligomères de CLR et de RAMP1, nous a amené à nous questionner sur la stœchiométrie d’interaction du complexe CLR/RAMP1. Dans une deuxième étude ayant pour but d’établir la composition moléculaire du récepteur CGRP1 in vivo, nous avons développé une nouvelle approche permettant l’étude de l’interaction entre trois protéines dans un contexte de cellules vivantes. Cette technique baptisée BRET/BiFC, est basée sur le transfert d’énergie de résonance de bioluminescence entre un donneur luminescent, la Renilla luciférase, et un accepteur fluorescent, la protéine fluorescente jaune (YFP), reconstituée suite au ré-assemblage de ces deux fragments. En utilisant cette approche, nous avons pu déterminer que le récepteur CGRP1 est constitué d’un homo-oligomère de CLR interagissant avec un monomère de RAMP1. En démontrant un assemblage oligomérique asymétrique pour le récepteur CGRP1 à partir d’une nouvelle approche biophysique, nous croyons que les travaux présentés dans cette thèse ont contribué à élargir nos connaissances sur le fonctionnement de la grande famille des RCPGs, et seront utile à la poursuite des recherches sur les complexes protéiques impliqués dans la signalisation. / G protein coupled receptors (GPCRs) constitute the largest family of membrane receptors involved in signal transduction. Traditionally, signal transduction by GPCRs involves the activation of a hetero-trimeric G protein which will then modulate the activity of several intracellular effectors. We can now appreciate the fact that in addition to their interaction with G proteins, GPCRs also associate with several other proteins, in order to allow proper signal transduction. In particular, the discovery of a family of proteins called receptor activity-modifying proteins (RAMPs) has challenged the traditional views of signal transduction by some GPCRs. In the case of the calcitonin-like receptor (CLR), the association with RAMPs allows the proper cell surface targeting of the receptor in addition to modulate it’s pharmacological properties. Co-expression of CLR with RAMP1 leads to a calcitonin gene-related peptide (CGRP) receptor, whereas CLR association with RAMP2 or RAMP3 promotes the formation of an adrenomedullin receptor. In addition to their interaction with transmembrane accessory proteins such as RAMPs, GPCRs can also interact with other receptors to form receptors oligomers. In this thesis, we were interested in the interactions between GPCRs and RAMPs, and particularly, in the link between these GPCR/RAMP interactions and the assembly of receptor oligomers, using CGRP1 receptor as a model. We first confirmed the interaction between CLR and RAMP1 in living cells. We showed that this CLR/RAMP1 complex activates G proteins and recruits the signalling protein -arrestin upon CGRP stimulation. Next, we demonstrated that even if the CLR requires hetero-oligomeric assembly with RAMPs in order to be active, this receptor can still interact with other GPCRs. In addition to CLR homo-oligomers, we observed that RAMPs can also self-associate to form oligomeric complexes which can involve different subtypes (RAMP1/RAMP2 and RAMP1/RAMP3). This observation of the presence of CLR and RAMP1 homo-oligomers raised the question of the stoiechiometry of interaction of the CLR/RAMP1 complex. In order to establish the molecular composition of the CGRP1 receptor in vivo, we developed a novel approach allowing the detection of the interaction between three proteins in living cells. This method called BRET/BiFC is based on the bioluminescence resonance energy transfer between a luminescent energy donor, Renilla luciferase, and a fluorescent energy acceptor, the yellow fluorescent protein (YFP), reconstituted after the re-association of its two fragments. Using this approach, we showed that the CGRP1 receptor consist of a homo-oligomer of CLR interacting with a monomer of RAMP1. By demonstrating the asymmetrical organization of the CGRP1 receptor complex using a novel biophysical approach, we believe that the results presented herein have contributed to increase our knowledge of the mechanisms of function of the large family of GPCRs and will be useful for the pursuit of research on protein complexes involved in signalling pathways.

INTRODUÇÃO: A toxina botulínica tipo A (TXB-A) tem sido testada no tratamento da rinite, principalmente nos casos de rinite idiopática. Sugere-se que um estado de hiper-reatividade do nervo trigêmeo esteja envolvido na fisiopatologia da rinite idiopática. O nervo trigêmeo possui fibras sensitivas não mielinizadas tipo C (FSNMT-C) que contém os neuropeptídeos substância P (SP) e peptídeo relacionado ao gene da calcitonina (CGRP). O óxido nítrico (NO) produzido pelas enzimas óxido nítrico sintase (NOS) também está envolvido nesse processo de neurorregulação nasal. O transporte mucociliar, mecanismo primário de defesa do sistema respiratório, é formado pelo batimento ciliar e muco nasal, e esses componentes podem ser influenciados por diferentes neuropeptídeos e neurotransmissores presentes na mucosa nasal. OBJETIVO: O objetivo deste estudo foi avaliar o efeito da TXB-A sobre a expressão da SP, CGRP e óxido nítrico sintase neural (nNOS), além de sua influência sobre o transporte mucociliar nasal em coelhos. MÉTODOS: Coelhos machos saudáveis da linhagem Nova Zelândia foram divididos em dois grupos: o grupo tratamento recebeu TXB-A (25UI) na concha nasomaxilar (CNM) do lado direito e soro fisiológico a 0,9% (SF0,9%) na CNM esquerda. O grupo controle recebeu SF0,9% na CNM direita e nenhuma intervenção na CNM esquerda. Foram investigados os efeitos da TXB-A sobre a expressão da SP, CGRP e nNOS no tecido de CNM por meio da imuno-histoquímica. Para esta análise, dividiu-se o tecido em camada externa (CE, acima da membrana basal) e camada interna (CI, abaixo da membrana basal). Avaliou-se também a presença de apoptose celular, a frequência de batimento ciliar (FBC), o perfil histoquímico do muco nasal (glicoproteínas ácidas e neutras) e a espessura do epitélio (ESP-CE). RESULTADOS: Foi observado um aumento significativo na quantidade de células apoptóticas na CNM do grupo tratamento que recebeu TXB-A em comparação aos controles (p <= 0,001). A CNM do grupo tratamento que recebeu SF0,9% exibiu um aumento na quantidade de células apoptóticas na CI ao comparar com os controles (CNM SF0,9%, p=0,035) (CNM sem intervenção, p=0,022), e também um aumento da expressão de SP na CE em comparação aos controles (CNM SF0,9%, p=0,021) (CNM sem intervenção, p=0,040). A expressão de CGRP apresentou um aumento na CNM do grupo tratamento que recebeu TXB-A em comparação à CNM sem intervenção (p=0,008). A FBC, expressão de nNOS, perfil histoquímico do muco nasal e ESP-CE não apresentaram diferenças significativas. DISCUSSÃO: O aumento da expressão de CGRP e SP pode ter sido causado por inibição de sua exocitose vesicular pela TXB-A, levando ao seu acúmulo intracelular. Não foram observadas diferenças significativas na FBC ou perfil histoquímico do muco nasal, indicando que o aumento da expressão de CGRP e SP não foi associado à inflamação. O aumento da quantidade de células apoptóticas e da expressão de SP na CNM SF0,9% do grupo tratamento pode ter sido causado por um efeito central da TXB-A. CONCLUSÃO: A administração nasal de TXB-A aumentou a expressão de CGRP e SP, possivelmente por acúmulo intracelular por causa da inibição da sua exocitose, mas sem alterar a FBC e o perfil histoquímico do muco nasal / INTRODUCTION: Botulinum toxin type A (BoNT-A) has been assessed in the treatment of rhinitis, especially in cases of idiopathic rhinitis. Trigeminal hyper-responsiveness appears to be involved in the pathological process of idiopathic rhinitis. Trigeminal nociceptive type C unmyelinated sensory fibers contain the neuropeptides calcitonin gene-related peptide (CGRP) and substance P (SP). Nitric oxide (NO) produced by the enzyme nitric oxide synthase (NOS) are also involved in this nasal neurorregulation process. The mucociliary clearance, primary defense system of the respiratory system, is composed by the ciliary beat and nasal mucus. These components can be influenced by different nasal neuropeptides and neurotransmitters. OBJECTIVE: The aim of this study was to evaluate the effect of BoNT-A on the expression of SP, CGRP and neural nitric oxide synthase (nNOS), and its influence on nasal mucociliary clearance in rabbits. METHODS: Healthy New Zealand male rabbits were divided into two groups: the treatment group was challenged with BoNT-A (25UI) in the right nasomaxillary turbinate (NMT) and saline (SF0.9%) in the left NMT. The control group received SF0.9% in the right NMT and no-intervention in the left NMT. We investigated the effects of BoNT-A on SP, CGRP and nNOS expression in the NMT tissue by immunohistochemistry. Each area of interest was subdivided into an internal layer (IL: below the basement membrane) and outer layer (OL: above the basement membrane) for analysis. It was also assessed signs of cellular apoptosis, ciliary beat frequency (CBF), mucus histochemical profile (acidic and neutral glycoproteins) and epithelial thickness (EP-TH). RESULTS: It was observed a significant increase in the amount of apoptotic cells in the BoNT-A-challanged NMT compared with controls (p <= 0.001). The NMT of treatment group which received only SF0.9% showed an increase in the amount of apoptotic cells in the IL compared with controls (NMT SF0.9%, p = 0.035) (NMT no-intervention, p = 0.022), and also an increase in the SP expression in the OL compared with controls (NMT SF0.9%, p = 0.021) (NMT no-intervention, p = 0.040). CGRP expression showed higher expression in the BoNT-A-challanged NMT compared with no-intervention NMT (p=0.008). The CBF, nNOS expression, mucus histochemical profile and EP-TH did not show significant differences. DISCUSSION: The increased CGRP and SP expression could be due to inhibition of vesicular exocytosis by BoNT-A, leading to CGRP and SP intracellular accumulation. No significant differences in CBF or mucus histochemical profile were observed, indicating that the increased CGRP and SP expression was not associated with inflammation. The increase in the amount of apoptotic cells and SP expression in the SF0.9% NMT of treatment group may be due to a central effect of BoNT-A. CONCLUSION: Nasal administration of BoNT-A increased SP and CGRP expression, possibly via inhibition of their release, but did not change the CBF or mucus profile

Les récepteurs couplés aux protéines G (RCPGs) constituent la plus grande classe de récepteurs membranaires impliqués dans la transmission des signaux extracellulaires. Traditionnellement, la transmission de la signalisation par les RCPGs implique l’activation d’une protéine G hétéro-trimérique qui pourra à son tour moduler l’activité de divers effecteurs intracellulaires. Ce schéma classique de signalisation s’est complexifié au fils des années et l’on sait maintenant qu’en plus d’interagir avec les protéines G, les RCPGs s’associent avec une panoplie d’autres protéines afin de transmettre adéquatement les signaux extracellulaires. En particulier, la découverte d’une famille de protéines transmembranaires modulant la fonction des RCPGs, baptisées protéines modifiant l’activité des récepteurs (« receptor activity-modifying proteins » ; RAMPs), a changé la façon de concevoir la signalisation par certains RCPGs. Dans le cas du récepteur similaire au récepteur de la calcitonine (« calcitonin-like receptor » ; CLR), l’association avec les RAMPs permet l’acheminement à la surface cellulaire du récepteur tout en modulant ses propriétés pharmacologiques. Lorsqu’il est associé avec RAMP1, le CLR fonctionne comme un récepteur du peptide relié au gène de la calcitonine (« calcitonin gene-related peptide » ; CGRP), alors qu’il devient un récepteur de l’adrénomedulline lorsqu’il interagit avec RAMP2 ou RAMP3. D’autre part, en plus d’interagir avec des protéines accessoires transmembranaires telles les RAMPs, les RCPGs peuvent aussi s’associer entre eux pour former des oligomères de récepteurs. Dans cette thèse, nous nous sommes penchés sur les interactions entre les RCPGs et les RAMPs, et plus particulièrement sur l’interrelation entre ce type d’association RCPG/RAMP et l’assemblage en oligomères de récepteurs, en utilisant le récepteur du CGRP comme modèle d’étude. Une première étude nous a tout d’abord permis de confirmer l’interaction entre le récepteur CLR et RAMP1, dans un contexte de cellules vivantes. Nous avons démontré que ce complexe CLR/RAMP1 active la protéine G et recrute la protéine de signalisation -arrestine suite à une stimulation par le CGRP. Ensuite, nous avons déterminé que même s’il doit obligatoirement former un hétéro-oligomère avec les RAMPs pour être actif, le CLR conserve malgré tout sa capacité à interagir avec d’autres RCPGs. En plus d’observer la présence d’homo-oligomère de CLR, nous avons constaté que tout comme les RCPGs, les RAMPs peuvent eux-aussi s’associer entre eux pour former des complexes oligomériques pouvant comprendre différents sous-types (RAMP1/RAMP2 et RAMP1/RAMP3). Cette observation de la présence d’homo-oligomères de CLR et de RAMP1, nous a amené à nous questionner sur la stœchiométrie d’interaction du complexe CLR/RAMP1. Dans une deuxième étude ayant pour but d’établir la composition moléculaire du récepteur CGRP1 in vivo, nous avons développé une nouvelle approche permettant l’étude de l’interaction entre trois protéines dans un contexte de cellules vivantes. Cette technique baptisée BRET/BiFC, est basée sur le transfert d’énergie de résonance de bioluminescence entre un donneur luminescent, la Renilla luciférase, et un accepteur fluorescent, la protéine fluorescente jaune (YFP), reconstituée suite au ré-assemblage de ces deux fragments. En utilisant cette approche, nous avons pu déterminer que le récepteur CGRP1 est constitué d’un homo-oligomère de CLR interagissant avec un monomère de RAMP1. En démontrant un assemblage oligomérique asymétrique pour le récepteur CGRP1 à partir d’une nouvelle approche biophysique, nous croyons que les travaux présentés dans cette thèse ont contribué à élargir nos connaissances sur le fonctionnement de la grande famille des RCPGs, et seront utile à la poursuite des recherches sur les complexes protéiques impliqués dans la signalisation. / G protein coupled receptors (GPCRs) constitute the largest family of membrane receptors involved in signal transduction. Traditionally, signal transduction by GPCRs involves the activation of a hetero-trimeric G protein which will then modulate the activity of several intracellular effectors. We can now appreciate the fact that in addition to their interaction with G proteins, GPCRs also associate with several other proteins, in order to allow proper signal transduction. In particular, the discovery of a family of proteins called receptor activity-modifying proteins (RAMPs) has challenged the traditional views of signal transduction by some GPCRs. In the case of the calcitonin-like receptor (CLR), the association with RAMPs allows the proper cell surface targeting of the receptor in addition to modulate it’s pharmacological properties. Co-expression of CLR with RAMP1 leads to a calcitonin gene-related peptide (CGRP) receptor, whereas CLR association with RAMP2 or RAMP3 promotes the formation of an adrenomedullin receptor. In addition to their interaction with transmembrane accessory proteins such as RAMPs, GPCRs can also interact with other receptors to form receptors oligomers. In this thesis, we were interested in the interactions between GPCRs and RAMPs, and particularly, in the link between these GPCR/RAMP interactions and the assembly of receptor oligomers, using CGRP1 receptor as a model. We first confirmed the interaction between CLR and RAMP1 in living cells. We showed that this CLR/RAMP1 complex activates G proteins and recruits the signalling protein -arrestin upon CGRP stimulation. Next, we demonstrated that even if the CLR requires hetero-oligomeric assembly with RAMPs in order to be active, this receptor can still interact with other GPCRs. In addition to CLR homo-oligomers, we observed that RAMPs can also self-associate to form oligomeric complexes which can involve different subtypes (RAMP1/RAMP2 and RAMP1/RAMP3). This observation of the presence of CLR and RAMP1 homo-oligomers raised the question of the stoiechiometry of interaction of the CLR/RAMP1 complex. In order to establish the molecular composition of the CGRP1 receptor in vivo, we developed a novel approach allowing the detection of the interaction between three proteins in living cells. This method called BRET/BiFC is based on the bioluminescence resonance energy transfer between a luminescent energy donor, Renilla luciferase, and a fluorescent energy acceptor, the yellow fluorescent protein (YFP), reconstituted after the re-association of its two fragments. Using this approach, we showed that the CGRP1 receptor consist of a homo-oligomer of CLR interacting with a monomer of RAMP1. By demonstrating the asymmetrical organization of the CGRP1 receptor complex using a novel biophysical approach, we believe that the results presented herein have contributed to increase our knowledge of the mechanisms of function of the large family of GPCRs and will be useful for the pursuit of research on protein complexes involved in signalling pathways.

INTRODUÇÃO: A toxina botulínica tipo A (TXB-A) tem sido testada no tratamento da rinite, principalmente nos casos de rinite idiopática. Sugere-se que um estado de hiper-reatividade do nervo trigêmeo esteja envolvido na fisiopatologia da rinite idiopática. O nervo trigêmeo possui fibras sensitivas não mielinizadas tipo C (FSNMT-C) que contém os neuropeptídeos substância P (SP) e peptídeo relacionado ao gene da calcitonina (CGRP). O óxido nítrico (NO) produzido pelas enzimas óxido nítrico sintase (NOS) também está envolvido nesse processo de neurorregulação nasal. O transporte mucociliar, mecanismo primário de defesa do sistema respiratório, é formado pelo batimento ciliar e muco nasal, e esses componentes podem ser influenciados por diferentes neuropeptídeos e neurotransmissores presentes na mucosa nasal. OBJETIVO: O objetivo deste estudo foi avaliar o efeito da TXB-A sobre a expressão da SP, CGRP e óxido nítrico sintase neural (nNOS), além de sua influência sobre o transporte mucociliar nasal em coelhos. MÉTODOS: Coelhos machos saudáveis da linhagem Nova Zelândia foram divididos em dois grupos: o grupo tratamento recebeu TXB-A (25UI) na concha nasomaxilar (CNM) do lado direito e soro fisiológico a 0,9% (SF0,9%) na CNM esquerda. O grupo controle recebeu SF0,9% na CNM direita e nenhuma intervenção na CNM esquerda. Foram investigados os efeitos da TXB-A sobre a expressão da SP, CGRP e nNOS no tecido de CNM por meio da imuno-histoquímica. Para esta análise, dividiu-se o tecido em camada externa (CE, acima da membrana basal) e camada interna (CI, abaixo da membrana basal). Avaliou-se também a presença de apoptose celular, a frequência de batimento ciliar (FBC), o perfil histoquímico do muco nasal (glicoproteínas ácidas e neutras) e a espessura do epitélio (ESP-CE). RESULTADOS: Foi observado um aumento significativo na quantidade de células apoptóticas na CNM do grupo tratamento que recebeu TXB-A em comparação aos controles (p <= 0,001). A CNM do grupo tratamento que recebeu SF0,9% exibiu um aumento na quantidade de células apoptóticas na CI ao comparar com os controles (CNM SF0,9%, p=0,035) (CNM sem intervenção, p=0,022), e também um aumento da expressão de SP na CE em comparação aos controles (CNM SF0,9%, p=0,021) (CNM sem intervenção, p=0,040). A expressão de CGRP apresentou um aumento na CNM do grupo tratamento que recebeu TXB-A em comparação à CNM sem intervenção (p=0,008). A FBC, expressão de nNOS, perfil histoquímico do muco nasal e ESP-CE não apresentaram diferenças significativas. DISCUSSÃO: O aumento da expressão de CGRP e SP pode ter sido causado por inibição de sua exocitose vesicular pela TXB-A, levando ao seu acúmulo intracelular. Não foram observadas diferenças significativas na FBC ou perfil histoquímico do muco nasal, indicando que o aumento da expressão de CGRP e SP não foi associado à inflamação. O aumento da quantidade de células apoptóticas e da expressão de SP na CNM SF0,9% do grupo tratamento pode ter sido causado por um efeito central da TXB-A. CONCLUSÃO: A administração nasal de TXB-A aumentou a expressão de CGRP e SP, possivelmente por acúmulo intracelular por causa da inibição da sua exocitose, mas sem alterar a FBC e o perfil histoquímico do muco nasal / INTRODUCTION: Botulinum toxin type A (BoNT-A) has been assessed in the treatment of rhinitis, especially in cases of idiopathic rhinitis. Trigeminal hyper-responsiveness appears to be involved in the pathological process of idiopathic rhinitis. Trigeminal nociceptive type C unmyelinated sensory fibers contain the neuropeptides calcitonin gene-related peptide (CGRP) and substance P (SP). Nitric oxide (NO) produced by the enzyme nitric oxide synthase (NOS) are also involved in this nasal neurorregulation process. The mucociliary clearance, primary defense system of the respiratory system, is composed by the ciliary beat and nasal mucus. These components can be influenced by different nasal neuropeptides and neurotransmitters. OBJECTIVE: The aim of this study was to evaluate the effect of BoNT-A on the expression of SP, CGRP and neural nitric oxide synthase (nNOS), and its influence on nasal mucociliary clearance in rabbits. METHODS: Healthy New Zealand male rabbits were divided into two groups: the treatment group was challenged with BoNT-A (25UI) in the right nasomaxillary turbinate (NMT) and saline (SF0.9%) in the left NMT. The control group received SF0.9% in the right NMT and no-intervention in the left NMT. We investigated the effects of BoNT-A on SP, CGRP and nNOS expression in the NMT tissue by immunohistochemistry. Each area of interest was subdivided into an internal layer (IL: below the basement membrane) and outer layer (OL: above the basement membrane) for analysis. It was also assessed signs of cellular apoptosis, ciliary beat frequency (CBF), mucus histochemical profile (acidic and neutral glycoproteins) and epithelial thickness (EP-TH). RESULTS: It was observed a significant increase in the amount of apoptotic cells in the BoNT-A-challanged NMT compared with controls (p <= 0.001). The NMT of treatment group which received only SF0.9% showed an increase in the amount of apoptotic cells in the IL compared with controls (NMT SF0.9%, p = 0.035) (NMT no-intervention, p = 0.022), and also an increase in the SP expression in the OL compared with controls (NMT SF0.9%, p = 0.021) (NMT no-intervention, p = 0.040). CGRP expression showed higher expression in the BoNT-A-challanged NMT compared with no-intervention NMT (p=0.008). The CBF, nNOS expression, mucus histochemical profile and EP-TH did not show significant differences. DISCUSSION: The increased CGRP and SP expression could be due to inhibition of vesicular exocytosis by BoNT-A, leading to CGRP and SP intracellular accumulation. No significant differences in CBF or mucus histochemical profile were observed, indicating that the increased CGRP and SP expression was not associated with inflammation. The increase in the amount of apoptotic cells and SP expression in the SF0.9% NMT of treatment group may be due to a central effect of BoNT-A. CONCLUSION: Nasal administration of BoNT-A increased SP and CGRP expression, possibly via inhibition of their release, but did not change the CBF or mucus profile