A melatonina (MEL), hormônio sintetizado pela glândula pineal apenas durante a noite, é um marcador circadiano interno. A sua produção depende de uma via neural temporizada pelo núcleo supraquiasmático (NSQ), que culmina na liberação rítmica noturna de noradrenalina na pineal, através de fibras simpáticas vindas do gânglio cervical superior (GCS). Sabendo que a pineal é essencialmente rítmica, foram estudados o relógio molecular da glândula pineal de ratos após GCSx e seus efeitos no relógio molecular do fígado e do NSQ. A GCSx alterou o relógio molecular da pineal, além de reduzir e tornar arrítmica a via de síntese de MEL. O fígado, um oscilador periférico, manteve a robustez de seu relógio, enquanto que o NSQ, oscilador central, teve sua expressão alterada, tanto no grupo GCSx, quanto após a remoção da pineal (PINX). O NSQ coordena os ritmos de atividade motora e temperatura, os quais exibiram alterações após a GCSx, sendo tais alterações ainda mais intensas após a PINX, com a redução da temperatura e aumento da atividade ao longo do tempo. Em conjunto, esses dados demonstram a complexidade do sistema circadiano e a importância da inervação simpática da pineal para, direta ou indiretamente, mantê-la inalterada. / Melatonin (MEL), a hormone synthesized by the pineal gland on the dark phase, is an internal circadian marker. Its production relies on a neural pathway timed by suprachiasmatic nuclei (SCN), which ends with the rhythmic release of norepinephrine by sympathetic fibers from the superior cervical ganglia (SCG). Since the pineal gland is essentially a rhythmic structure, the aim of this study were evaluate the molecular clock of pineal gland after the superior cervical ganglia ablation (SCGx) and its effects on liver and SCN molecular clocks. The SCGs modified the molecular clock of pineal gland and, in addition, the MEL synthesis pathway was decreased and became arrhythmic. Besides that, the molecular clock of liver maintained its robustness, while the SCN\'s, the master clock, was changed in SGCx and after pineal removal. The SCN coordinates the rhythms of motor activity and temperature. Those are changed after SCGx, although the removal of pineal gland had changed them more, decreasing the temperature and increasing motor activity over the time. Together, these data show the complexity of the circadian system and the relevance of pineal sympathetic innervation to, direct or indireclty, maintain it unaltered.

Les services de Neurochirurgie du Groupement Hospitalier Est de Lyon ont une expérience reconnue pour l’exérèse des tumeurs des régions périventriculaires du système nerveux central notamment au niveau de la région pinéale. Dans ce contexte neurochirurgical favorable et avec l’opportunité d’utiliser des techniques de biologie moléculaire, notre objectif a été l’identification de marqueurs diagnostiques pour chaque type tumoral par une étude transcriptomique en microarray, la caractérisation d’un sous-type de tumeur du parenchyme pinéal (TPP) pléïomorphe, l’évaluation de la synthèse de mélatonine par les TPP et l’étude du transcriptome de certains organes circumventriculaires (OCV) microdisséqués chez le rat. L’analyse du transcriptome des tumeurs périventriculaires a permis de regrouper les tumeurs par leur signature moléculaire et d’identifier des marqueurs diagnostiques pour chaque type tumoral. De nouveaux marqueurs pronostiques potentiels (HoxD13, Prame, CD24 et Pou4f2 et gènes de la voie Aurora kinase B) sont proposés en vue d’améliorer la classification des TPP. Pour ces dernières, une étude multicentrique a permis de caractériser un sous-type tumoral, les tumeurs pléïomorphes, souvent surgradées. L’étude des TPP ex vivo et in vivo montre leur capacité de synthèse de mélatonine. Toutefois, nous n’avons pu obtenir une lignée de cellules tumorales stable. La microdissection des OCV du rat, parfois vestigiaux chez l’homme et qui pourraient être à l’origine de tumeurs périventriculaires, a permis d’étudier leur transcriptome et de mettre en évidence des marqueurs nouveaux ou déjà associés dans la littérature à ces structures / Neurosurgery of periventricular tumors, especially of pineal region tumors, is well developed at the Neurosurgical Hospital in Lyon. Taking opportunity of this background, our objective was identification of new diagnostic markers for each of these tumors using microarray transcriptome analysis, characterisation of a pleomorphic pineal parenchyma tumor (PPT) subtype, evaluation of melatonin synthesis in PPTs and the microarray analysis of molecular signature of some of circumventricular organs (CVO) after their laser microdissection in rat. The microarray analysis of periventricular tumors allowed molecular classification of the tumours and revealed different diagnostic markers for each type of tumors. Potentially new prognostic candidate genes (HoxD13, Prame, CD24 and Pou4f2 and Aurora kinase B pathway genes) are proposed for improvement of PPT classification. A PPT multicenter study allowed the characterisation of a pleomorphic subtype frequently managed as a higher grade tumour in the literature. The study of PPT ex vivo and in vivo showed their preserved capacity for melatonin production. However a stable PPT cell line culture could not be obtained. The laser microdissection of OCV in rat, sometimes vestigial in humans and potentially at the origin of the periventricular tumors, associated with a microarray study highlighted some potentially new or already described specific markers of these structures

A pineal participa da sincronização do organismo pela síntese de melatonina. Diabetes é um distúrbio metabólico caracterizado por hiperglicemia. Diante da controvérsia sobre a síntese de melatonina em animais diabéticos, esse trabalho objetivou avaliar as alterações da glândula pineal mediante o diabetes induzido por STZ (60mg/kg, i.p.). Ratos wistar (250-280g, 12h/12h claro/escuro) foram utilizados em todos os procedimentos que envolveram técnicas de FACS, microdiálise, HPLC, radiometria da atividade enzimática e qPCR. Os resultados mostraram que o diabetes causa diminuição (50%) e perda do perfil mono/bifásico da síntese pineal de melatonina, que não é causada por necrose ou apoptose dos pinealócitos e reflete um desarranjo no metabolismo pineal, evidenciado pela diminuição na atividade da AANAT (55%). Observou-se também um desbalanço rítmico de fatores determinantes como a expressão do receptor ß1 e a atividade e expressão das enzimas TPH1 e HIOMT. A menor concentração de melatonina circulante pode ser um fator contribuinte para o desenvolvimento da doença. / The gland is involved in the organism synchronization via its hormone melatonin. Diabetes involves hyperglicemia and insulin synthesis/signaling impairment. The aim of this work was to evaluate the pineal melatonin synthesis in STZ-diabetic rats (60mg/kg, i.p.). Male wistar rats (250-280g, 12h/12h light/dark) were used as the animal model and FACS, microdialysis, HPLC, enzyme activity assay and qPCR were the techniques used to evaluate the pineal phisiology. The results show a decrease in pineal melatonin (50%) and a circadian profile impairment that were not due to necrosis or apoptosis. This finding reflects an important impairment in the pineal metabolism that was related to a decrease in AANAT activity (55%). An alteration in the rhthmicity of important factors, such as the ß1-adrenergic receptor expression and the TPH1 and HIOMT activity and expression, was also observed. This decrease in circulating melatonin may be of fundamental importance to the establishment and maintenance of diabetes.

Bibliography: leaves 168-187. / viii, a-f, 187, [51] leaves, [12] leaves of plates : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Investigates the environmental control of seasonal reproduction and the role of the pineal in the transmission of multiple environmental signals to the reproductive axis. The principle species studied was the highly seasonal native Australian bush rat, Rattus fuscipes greyi. / Thesis (Ph.D.)--University of Adelaide, Dept. of Obstetrics and Gynaecology, 1994

No description available.

Raumforderungen der PR haben ihren Ursprung zum einen in den pinealen Geweben und zum anderen in den heterogenen Strukturen des ZNS. Aufgrund ihrer anatomischen Lage im Bereich der zirkumventrikulären GP und des Hirnstammes bedeuten sie im fortgeschrittenen Stadium für die Patienten eine massiv eingeschränkte Lebensqualität bei zunehmend schlechter Prognose. Die Heterogenität dieser Tumoren stellt die Medizin jedoch vor eine große diagnostische und therapeutische Herausforderung. Entscheidend für eine optimale Therapie ist eine eindeutige Charakterisierung dieser Raumforderungen. In dieser Arbeit ist es erstmals gelungen, neben pineal-parenchymalen Raumforderungen und Keimzelltumoren der PR, pilozytische Astrozytome, einen solid-fibrösen und einen neuroendokrinen Tumor der PR molekularzytogenetisch zu charakterisieren. Die Karzinogenese der Raumforderungen der PR ist nicht abschließend geklärt. Von Tumoren, die einer histologischen Zellpopulation entsprächen, wären in Regelhaftigkeit identische genetische Veränderungen zu erwarten. Die Analysen in dieser Arbeit zeigen zum einen übereinstimmende molekularzytogenetische Veränderungen der Chromosomen 7, 9, 12 und 17 mit zuvor beschriebenen Tumoren der PR. Zudem konnte erstmals eine Vielzahl neuer chromosomaler Veränderungen beschrieben werden. Diese molekulargenetische Heterogenität stellt die aktuelle Zuordnung der Raumforderungen der PR nicht in Frage, unterstreicht jedoch, dass eine weitere histologische Charakterisierung notwendig ist, um Subgruppen zu identifizieren. Sie zeigt, dass klassische Konzepte der Tumorigenese die molekularzytogenetische Heterogenität dieser Tumoren nur unzureichend beschreiben und durch progressivere Tumormodelle ergänzt werden müssen (Berger et al. 2011). Tumoren und Raumforderungen der PR entsprechen im Kindesalter 3-8% und im Erwachsenenalter weniger als 1% aller intrazerebralen Raumforderungen (Edwards et al. 1988; Regis et al. 1996; Rickert et al. 2001), so dass Untersuchungen größerer Patienten-kollektive über einen längeren Zeitraum schwierig sind. Die molekular¬zytogenetische Zuordnung der in dieser Arbeit untersuchten Raumforderungen unterstützt und ergänzt die Charakterisierung der Tumorentitäten. Auch wenn nur eine geringe Tumoranzahl über einen längeren Zeitraum untersucht werden konnte, so ist anzunehmen, dass es möglich sein wird, einzelnen histologischen Entitäten ein zytogenetisches Muster zuzuordnen, wenn größere Tumorkollektive der PR untersucht werden. So kann die Diagnostik erweitert und eine prognostische Bedeutung zum Wohle der Patienten erlangt werden.

Estruturas da glândula pineal humana foram estudadas empregando os métodos de microscopia de luz, microscopia eletrônica de varredura, microscopia de varredura por espectrometria de raio-x e difração de raio-x. As peças para microscopia de luz foram fixadas em solução de formalina a 10% durante 48h e incluídas em parafina. Para a microscopia eletrônica de varredura, as peças foram fixadas em solução de Karnovsky modificada, sendo que parte das peças foram fraturadas em nitrogênio líquido para o exame das características internas do corpo píneal. Os resultados evidenciaram que o corpo píneal apresenta formações calcáreas distribuídas no interior do tecido conjuntivo. As formações calcáreas possuem tamanhos e formas diferentes. As estruturas calcáreas apresentam uma cápsula constituída pelo tecido conjuntivo. Na porção interna, a estrutura calcárea é constituída por uma série de !ameias concêntricas, com porosidade de aspecto amorfo. Evidenciou-se pela análise de difração de raio-x, a estrutura cristalina formada pelos átomos de vários elementos que compõem a formação calc área . / The structure of human pineal gland was studied by optic microscopy, scanning eletromicroscopy, spectrometer x-ray scanning eletron microscopy with energy dispersion (EDS). The tissues to analysis by optic microscopy were fixed in formalin at 1O % during 48 h and put in parffin. For S.E.M., the tissues were fixed in modified Kamovsky solution, and a part of the material was fracturated in liquid nitrogen to analysis of internal characteristic of the pineal body. The results showed that the pineal body has calcareon concretion distributed in the connective tissue. In the internai position, the calcareon structure was made of concentrics lamelae with amorf aspect. The x-ray difractor showed the cristalin structure of the atom arrangement of the elements that compose the calcarean concretions.

A pineal participa da sincronização do organismo pela síntese de melatonina. Diabetes é um distúrbio metabólico caracterizado por hiperglicemia. Diante da controvérsia sobre a síntese de melatonina em animais diabéticos, esse trabalho objetivou avaliar as alterações da glândula pineal mediante o diabetes induzido por STZ (60mg/kg, i.p.). Ratos wistar (250-280g, 12h/12h claro/escuro) foram utilizados em todos os procedimentos que envolveram técnicas de FACS, microdiálise, HPLC, radiometria da atividade enzimática e qPCR. Os resultados mostraram que o diabetes causa diminuição (50%) e perda do perfil mono/bifásico da síntese pineal de melatonina, que não é causada por necrose ou apoptose dos pinealócitos e reflete um desarranjo no metabolismo pineal, evidenciado pela diminuição na atividade da AANAT (55%). Observou-se também um desbalanço rítmico de fatores determinantes como a expressão do receptor ß1 e a atividade e expressão das enzimas TPH1 e HIOMT. A menor concentração de melatonina circulante pode ser um fator contribuinte para o desenvolvimento da doença. / The gland is involved in the organism synchronization via its hormone melatonin. Diabetes involves hyperglicemia and insulin synthesis/signaling impairment. The aim of this work was to evaluate the pineal melatonin synthesis in STZ-diabetic rats (60mg/kg, i.p.). Male wistar rats (250-280g, 12h/12h light/dark) were used as the animal model and FACS, microdialysis, HPLC, enzyme activity assay and qPCR were the techniques used to evaluate the pineal phisiology. The results show a decrease in pineal melatonin (50%) and a circadian profile impairment that were not due to necrosis or apoptosis. This finding reflects an important impairment in the pineal metabolism that was related to a decrease in AANAT activity (55%). An alteration in the rhthmicity of important factors, such as the ß1-adrenergic receptor expression and the TPH1 and HIOMT activity and expression, was also observed. This decrease in circulating melatonin may be of fundamental importance to the establishment and maintenance of diabetes.

Circadian rhythm is a biological rhythm with period of about 24 hours. Circadian rhythm is universal in phyla from bacteria to mammals and exists in different level from gene expression to behavior. Circadian system consists of three components: 1) a self-sustained oscillator; 2) an input pathway which can alter the phase of the oscillator; and 3) an output such as gene expression, enzyme activity, hormone production, heart rate, body temperature or locomotor activities. The way the oscillator regulates its outputs is complicated, in that on one hand usually the oscillator is not the only factor affecting the outputs, and on the other, the oscillator itself is incorporated in intricate pathways. Chicken pineal cell culture is a well-established in vitro model to study circadian rhythm. It contains a self-sustained oscillator which can be phase-shifted by light as input and rhythmically releases melatonin as an output. Here I have characterized the role of norepinephrine (NE), the sympathetic regulatory input of pineal gland, and the microenvironment of pineal cells in melatonin rhythmicity of cultured chicken pineal cells. Chapter 1 of this dissertation provides a review of circadian rhythm with a focus on melatonin regulation in pineal gland. Chapter 2 describes the methods to build up a fraction collector which offers high time resolution of sampling for a superfusion system. Chapter 3 is a technical report of a melatonin enzyme-linked immunosorbent assay suitable for high throughput measurement of melatonin. Chapter 4 presents data demonstrating that daily administration of NE recovers damped melatonin rhythm in constant darkness. In addition, NE does not change the expression of clock genes but the recovery effect of NE depends on the internal clock. Furthermore, the data indicates that NE administration stimulates the gene expression of phosphodiesterase 4D (PDE4D) and adenylate cyclase 1 (AC1) in a time order, potentially corresponding to the trough and peak of recovered melatonin rhythm. Chapter 5 presents data showing that the amplitude of melatonin rhythm in cultured pineal cells is affected by microenvironments of the cell culture and connexin plays a role in this effect. Finally, in Chapter 6 I discuss how the results of each chapter demonstrate multiple regulatory mechanism of the melatonin rhythm of chicken pineal cells. Furthermore, I discuss the implications of this work in the field of developmental biology and how the current data will shape future investigations. My dissertation incorporates engineering, immunocytochemistry, chicken genetics, and biochemical analyses, and will help in better understanding the regulation mechanism of output in a circadian system.

The biological clock are responsible for entraining of circadian rhytms in many physiological and behavioral functions, including the activity of immune system. In mammals, the biological clock are located in the suprachiasmatic nuclei of the hypothalamus and also on the periphery. The main oscillator in suprachiamatic nuclei synchronizes the phases of the peripheral oscillators in tissues and the other brain areas and it also drives synthesis of melatonin in the pineal gland. Its endogenous period Tau (τ) is being synchronized with external 24-hour day under normal conditions, mostly by the light-dark cycles during the day and night and also by non-photic stimuli. By the application of endotoxin, disruption of normal endogenous conditions in organism causes activation of the immune response, behavioral changes and phase shifts of the circadian rhythmicity. This work examines effect of acute application endotoxin lipopolysaccharid on the cellular signaling cascades in the cells of suprachiasmatic nuclei and pineal gland. Our data indicate, that levels of phosphorylated forms of kinases GSK3β, ERK1/2 and levels of phosphorylated forms transcription factors STAT3 are substantially modificated after administration of lipopolysaccharid in the suprachiasmatic nuclei and especially in the pineal gland of...