Approximately 1 in 6 infants are born prematurely each year. Typically, these infants spend 25 days in the Neonatal Intensive Care Unit (NICU) where they experience 10-18 painful and inflammatory procedures each day. Remarkably, pre-emptive analgesics and/or anesthesia are administered less than 30% of the time. Unalleviated pain during the perinatal period is associated with permanent decreases in pain sensitivity, blunted cortisol responses and high rates of neuropsychiatric disorders. To date, the mechanism(s) by which these long-term changes in stress and pain behavior occur, and whether such alterations can be prevented by appropriate analgesia at the time of injury, remains unclear. We have previously reported in rats that inflammation experienced on the day of birth permanently upregulates central opioid tone, resulting in a significant reduction in adult pain sensitivity. However, the impact on early life pain on anxiety- and stress-related behavior and HPA axis regulation is not known. Therefore the goal of this dissertation was to determine the long-term impact of a single neonatal inflammatory pain experience on adult anxiety- and stress-related responses. Neuroanatomical changes in stress-associated neurocircuits were also examined. As the endogenous pain control system and HPA axis are in a state of exaggerated developmental plasticity early in postnatal life, and these systems work in concert to respond to noxious or aversive stimuli, this dissertation research aimed to answer the following questions: (1) Does neonatal injury produce deficits in adult stress-related behavior and alter stress-related neuroanatomy through an opioid-dependent mechanism? (2) Does neonatal injury alter receptor systems regulating the activation and termination of the stress response in adulthood? (3) Are stress- and pain-related neurotransmitters altered within the first week following early life pain? (4) Is early activation of the pain system necessary for the long-term changes in anxiety- and stress-related behavior? Together these studies demonstrate the degree, severity and preventability of the long-term deficits in stress responding associated with a single painful experience early in life. The goal of this research is to promote change in the treatment of infant pain in the NICU to reduce long-term sensory and mental health complications associated with prematurity.

No description available.

Approximately 1 in 6 infants are born prematurely each year. Typically, these infants spend 25 days in the Neonatal Intensive Care Unit (NICU) where they experience 10-18 painful and inflammatory procedures each day. Remarkably, pre-emptive analgesics and/or anesthesia are administered less than 30% of the time. Unalleviated pain during the perinatal period is associated with permanent decreases in pain sensitivity, blunted cortisol responses and high rates of neuropsychiatric disorders. To date, the mechanism(s) by which these long-term changes in stress and pain behavior occur, and whether such alterations can be prevented by appropriate analgesia at the time of injury, remains unclear. We have previously reported in rats that inflammation experienced on the day of birth permanently upregulates central opioid tone, resulting in a significant reduction in adult pain sensitivity. However, the impact on early life pain on anxiety- and stress-related behavior and HPA axis regulation is not known. Therefore the goal of this dissertation was to determine the long-term impact of a single neonatal inflammatory pain experience on adult anxiety- and stress-related responses. Neuroanatomical changes in stress-associated neurocircuits were also examined. As the endogenous pain control system and HPA axis are in a state of exaggerated developmental plasticity early in postnatal life, and these systems work in concert to respond to noxious or aversive stimuli, this dissertation research aimed to answer the following questions: (1) Does neonatal injury produce deficits in adult stress-related behavior and alter stress-related neuroanatomy through an opioid-dependent mechanism? (2) Does neonatal injury alter receptor systems regulating the activation and termination of the stress response in adulthood? (3) Are stress- and pain-related neurotransmitters altered within the first week following early life pain? (4) Is early activation of the pain system necessary for the long-term changes in anxiety- and stress-related behavior? Together these studies demonstrate the degree, severity and preventability of the long-term deficits in stress responding associated with a single painful experience early in life. The goal of this research is to promote change in the treatment of infant pain in the NICU to reduce long-term sensory and mental health complications associated with prematurity.

INTRODUCTION Des réponses thérapeutiques variables aux glucocorticoïdes (GCs) sont observées parmi les patients atteints de la leucémie lymphoblastique aiguë (LLA). Les protéines Bax et Bim ont déjà montré un rôle important dans l’apoptose des cellules leucémiques. L’expression de Bax était plus basse chez les patients leucémiques résistants au médicament, de même une sensibilité diminuée aux GCs a été associée avec une expression réduite de Bim. La différence dans l’expression pourrait être due à des polymorphismes présents dans ces gènes et donc être associés avec la résistance aux GCs. MÉTHODE Dix-huit polymorphismes en régions régulatrices, 2 polymorphismes exoniques et 7 polymorphismes en région 3’UTR de ces gènes ont été analysés chez les témoins (n=50) et ont permis de déterminer un nombre minimal de polymorphismes suffisants pour définir les haplotypes (tagSNPs). Ces 8 polymorphismes ont ensuite été génotypés chez 286 enfants atteints de la LLA et ont été testés pour l’issue de la maladie par l’analyse de survie. RÉSULTATS Une survie sans évènement et une survie sans rechute diminuées ont été observées pour l’haplotype 3 (p=0,03 et p=0,02). Une survie globale diminuée a été associée avec l’homozygotie pour l’allèle exonique T298C>T (p=0,03), de même que pour les haplotypes 1 et 4 (p=0,04 et p=0,02) du gène Bim. CONCLUSION Les polymorphismes ont été associés avec une survie diminuée chez des enfants atteints de LLA. Il reste à tester d’autres polymorphismes présents dans ces deux gènes ainsi qu’à définir leurs fonctions afin de comprendre leurs rôles dans la réponse aux GCs. / INTRODUCTION Variable therapeutic responses to glucocorticoids (GCs) are observed for acute lymphoblastic leukemia (ALL) patients. Proteins Bax and Bim have already shown to play a major role in mediating GC-induced apoptosis in leukemia cells. Bax expression was lower in drug-resistant leukemia samples; likewise lower sensitivity to GC was associated with reduced Bim expression. The difference in the expression can be due to polymorphisms in these genes and therefore associated to GC resistance. METHOD Eighteen polymorphisms in the regulatory region, two exonic polymorphisms and seven polymorphisms in 3’UTR of these genes were analysed in controls (n=50) and have permitted to determine a minimal number of polymorphisms sufficient to define haplotypes (tagSNPs). These 8 single nucleotide polymorphisms (SNPs) were then genotyped in 286 LLA children and were tested for disease outcome by survival analysis. RESULTS A diminished event free survival and a diminished relapse free survival were observed for haplotype 3 (p=0,03 and p=0,02). A diminished overall survival was associated with the exonic T298C>T allele (p=0,03) and with haplotypes 1 and 4 (p=004 and p=0,02) of Bim gene. CONCLUSION Bax and Bim were associated with a diminished survival in LLA children. We still have to test other polymorphisms located in these genes and to define their functions in order to understand their roles in GC response.

L'axe hypothalamo-hypophyso-surrénalien (HPA) permet de maintenir l'homéostasie de l'organisme face à divers stress. Qu'ils soient de nature psychologique, physique ou inflammatoire/infectieux, les stress provoquent la synthèse et la libération de CRH par l'hypothalamus. Les cellules corticotropes hypophysaires perçoivent ce signal et en réaction, produisent et sécrètent l'ACTH. Ceci induit la synthèse des glucocorticoïdes (Gc) par le cortex surrénalien; ces stéroïdes mettent le système métabolique en état d’alerte pour la réponse au stress et à l’agression. Les Gc ont le rôle essentiel de contrôler les défenses de l'organisme, en plus d'exercer une rétro-inhibition sur l'axe HPA. L'ACTH est une petite hormone peptidique produite par le clivage d'un précurseur: la pro-opiomélanocortine (POMC). À cause de sa position critique dans la normalisation de l'homéostasie, le contrôle transcriptionnel du gène Pomc a fait l'objet d'études approfondies au cours des dernières décennies. Nous savons maintenant que la région promotrice du gène Pomc permet une expression ciblée dans les cellules POMC hypophysaires. L'étude du locus Pomc par des technologies génomiques m'a permis de découvrir un nouvel élément de régulation qui est conservé à travers l'évolution des mammifères. La caractérisation de cet enhancer a démontré qu'il dirige une expression restreinte à l'hypophyse, et plus particulièrement dans les cellules corticotropes. De façon intéressante, l'activité de cet élément dépend d'un nouveau site de liaison recrutant un homodimère du facteur de transcription Tpit, dont l'expression est également limitée aux cellules POMC de l'hypophyse. La découverte de cet enhancer ajoute une toute nouvelle dimension à la régulation de l'expression de POMC. Les cytokines pro-inflammatoires IL6/LIF et les Gc sont connus pour leur antagonisme sur la réaction inflammatoire et sur le promoteur Pomc via l'action des facteurs de transcription Stat3 et GR respectivement. L'analyse génomique des sites liés ii par ces deux facteurs nous a révélé une interrelation complexe et a permis de définir un code transcriptionnel entre ces voies de signalisation. En plus de leur action par interaction directe avec l’ADN au niveau des séquences régulatrices, ces facteurs interagissent directement entre eux avec des résultats transcriptionnels différents. Ainsi, le recrutement de GR par contact protéine:protéine (tethering) sur Stat3 étant lié à l'ADN provoque un antagonisme transcriptionnel. Inversement, le tethering de Stat3 sur GR supporte une action synergique, tout comme leur co-recrutement à l'ADN sur des sites contigus ou composites. Lors d'une activation soutenue, ce synergisme entre les voies IL6/LIF et Gc induit une réponse innée de défense cellulaire. Ainsi lors d'un stress majeur, ce mécanisme de défense est mis en branle dans toutes les cellules et tissus. En somme, les travaux présentés dans cette thèse définissent les mécanismes transcriptionnels engagés dans le combat de l'organisme contre les stress. Plus particulièrement, ces mécanismes ont été décrits au niveau de la réponse globale des corticotropes et du gène Pomc. Il est essentiel pour l'organisme d'induire adéquatement ces mécanismes afin de faire face aux stress et d'éviter des dérèglements comme les maladies inflammatoires et métaboliques. / The hypothalamo-pituitary-adrenal (HPA) axis regulates homeostasis in various conditions of stress contributing to both the stress response and its termination. Psychological, physical or inflammatory/infectious stresses all prompt the synthesis and secretion of hypothalamic CRH. The pituitary corticotrope cells receive this signal and in turn, secrete ACTH which triggers the synthesis of glucocorticoids (Gc) by the adrenal cortex; these steroids induce a general state of alertness in order to fight or flight aggressions and stresses. Glucocorticoids have the critical role to restrict the stress response by exerting a negative feedback on the HPA axis. ACTH is a small peptidic hormone produced after cleavage of a precursor protein: pro-opiomelanocortin (POMC). Due to its critical role in homeostasis, transcriptional control of the Pomc gene has been intensely studied during the last decades. Previous investigations identified a promoter region that is sufficient for expression of Pomc in the appropriate pituitary cells. Genome-wide studies of the Pomc locus led me to discover a novel regulatory element that is conserved throughout mammalian evolution. The activity of this enhancer is restricted to the pituitary, and more precisely to the corticotrope lineage. Interestingly, its activity depends on a novel transcription factor binding motif that binds homodimers of Tpit, a transcription factor that is only found in pituitary POMC cells. The discovery of this enhancer adds a new dimension in the control of pituitary Pomc expression. The IL6/LIF pro-inflammatory cytokines and the glucocorticoids are well known for their antagonism in control of the inflammatory response; at the Pomc promoter, their action is mediated by the transcription factors Stat3 and GR, respectively. The analysis of genomic sites bound by these two factors revealed a complex relationship and led us to define a transcription regulatory code linking these signalling pathways. In addition to their direct DNA interaction with cognate regulatory sequences, these factors iv interact with each other with different outcomes. Thus, the recruitment of GR on DNAbound Stat3 through protein:protein contacts (tethering) results in transcriptional antagonism. Conversely, Stat3 tethering to GR produces synergism; this is also the case when the two factors are co-recruited to DNA on contiguous or composite binding sites. Prolonged activation of the IL6/LIF and Gc pathways elicits a synergistic innate cell defense response in all cells and tissues. In summary, this doctoral work has defined transcriptional mechanisms that mediate and control the stress response. In particular, pituitary components of the stress response were defined at the level of the Pomc gene and as a global response of corticotrope cells. This response is critical for appropriate organism defense during stresses such as those produced in inflammatory and metabolic diseases.

No description available.

Teneurin C-terminal associated peptides (TCAP) are a family of bioactive peptides found on the terminal exon of the four teneurin genes. TCAP-1 is found within brain regions that modulate the activity of corticotropin-releasing factor (CRF), which is the principal neuropeptide regulator of the hypothalamic-pituitary-adrenal (HPA) axis. TCAP-1 has suppressive effects on CRF-induced anxiety behaviours in rats. However, previous studies determined that TCAP-1 does not act directly on the CRF receptors (CRFR). Thus, I postulate that TCAP-1 may act centrally to modify elements of the HPA axis. Using an immortalized mouse hippocampal cell line, I tested the hypothesis that TCAP acts either downstream of CRFR activation, or on the regulation of the glucocorticoid receptors (GCR), which modulate CRF actions. These studies indicate that TCAP-1 represents a novel peptide in the regulation of stress related systems, which acts independently of either CRF-, or glucocorticoid- mediated signal transduction and transcription.

Teneurin C-terminal associated peptides (TCAP) are a family of bioactive peptides found on the terminal exon of the four teneurin genes. TCAP-1 is found within brain regions that modulate the activity of corticotropin-releasing factor (CRF), which is the principal neuropeptide regulator of the hypothalamic-pituitary-adrenal (HPA) axis. TCAP-1 has suppressive effects on CRF-induced anxiety behaviours in rats. However, previous studies determined that TCAP-1 does not act directly on the CRF receptors (CRFR). Thus, I postulate that TCAP-1 may act centrally to modify elements of the HPA axis. Using an immortalized mouse hippocampal cell line, I tested the hypothesis that TCAP acts either downstream of CRFR activation, or on the regulation of the glucocorticoid receptors (GCR), which modulate CRF actions. These studies indicate that TCAP-1 represents a novel peptide in the regulation of stress related systems, which acts independently of either CRF-, or glucocorticoid- mediated signal transduction and transcription.

A modulação da resposta inflamatória uterina equina recebe atenção, devido a um distúrbio imunológico, que parece ocorrer em uma população de éguas, classificadas como suscetíveis à endometrite. O objetivo deste estudo foi verificar o efeito da corticoterapia aplicada na presença e na ausência de inflamação uterina sobre a proteômica e a concentração de óxido nítrico no líquido endometrial de éguas suscetíveis à endometrite. Éguas foram sincronizadas com 5 mg de prostaglandina F2α e após a verificação dos sinais de estro foram submetidas a quatro tratamentos. O primeiro foi o Controle, que não recebeu nenhum tipo de tratamento. O segundo foi o GC, onde as éguas receberam aplicação de um glicocorticóide, a cada 12 horas, por três dias consecutivos. O terceiro foi o Infectado, onde as éguas receberam uma infusão intrauterina de Streptococcus zoopepidemicus (1x109/mL) e o quarto foi o GC + Infectado, onde as éguas receberam a aplicação do glicocorticóide e a infusão intrauterina descrita acima. Doze horas após o final de cada tratamento, amostras de líquido endometrial puro e de lavados uterinos foram coletadas para análise proteômica e determinação de óxido nítrico, respectivamente. O primeiro artigo relata os dados preliminares da análise proteômica, com a contagem das bandas protéicas e a observação de 33 bandas protéicas no Controle, 54 no GC, 51 no Infectado e 72 no GC + Infectado. A corticoterapia pode induzir o aparecimento de um número maior de bandas protéicas, pois os géis com as maiores contagens foram nos tratamentos onde ela foi aplicada. No segundo artigo, foi realizada a identificação das bandas protéicas significativas, em relação à densidade óptica relativa e à frequência. A corticoterapia provocou uma alteração na proteômica do líquido endometrial, caracterizada pelo aumento e diminuição na densidade óptica relativa e na frequência de proteínas da fase aguda da inflamação, com as maiores alterações observadas quando a corticoterapia foi aplicada na presença do processo infeccioso. A infusão de Streptococcus zooepidemicus provocou alterações na proteômica do líquido endometrial, caracterizadas pelo aumento e diminuição na densidade óptica relativa e na frequência de proteínas da fase aguda da inflamação. Os resultados do estudo indicam que a corticoterapia provoca alterações imunológicas no endométrio equino, não apenas como depressiva, mas estimuladora da defesa local, através de uma ação imunomoduladora. No terceiro artigo, foi realizada a determinação da concentração de óxido nítrico, não sendo observada diferença significativa nos quatro tratamentos. Portanto, a corticoterapia provoca alterações proteômicas no líquido endometrial de éguas suscetíveis em estro, onde a presença de um estímulo inflamatório causado pela infusão intrauterina bacteriana induz a uma maior alteração, do que a ausência. A infecção do lúmen uterino provoca alterações proteômicas no líquido endometrial e a corticoterapia não influencia a concentração de óxido nítrico de éguas em estro. / The modulation of the equine uterine inflammatory response recieves much attention, due to an immunological disorder, which appears to happen in a population of mares, classified as suscetipble to endometritis. The aim of this study was to verify the effect of corticotherapy applied in the presence and in the absence of uterine inflammation on the proteomics and nitric oxide concentration of the endometrial fluid of mares susceptible to endometritis. Mares were synchronized with 5 mg prostaglandin F2α and after the observation of the signs of estrus were submitted to four treatments. The first was the Control, which did not recieve any kind of treatment. The second was the GC, where mares recieved the administration of a glucocorticoid, each 12 hours, for three consecutive days. The third was the Infected, where mares received an intrauterine infusion of Streptococcus zoopepidemicus (1x109/mL) and the fourth was the GC + Infected, where mares received the administration of glucocorticoid and intrauterine infusion as described above. Twelve hours after the end of each treatment, pure endometrial fluid and uterine flushings were collected for proteomic analysis and nitric oxide determination, respectively. The first article reports the preliminary data of the proteomic analysis, where protein band counts were done, being observed 33 protein bands in Control, 54 in GC, 51 in Infected and 72 in GC + Infected. Corticotherapy can induce the appearance of a higher number of protein bands, because the gels with the highest counts were in the treatments where it was applied. In the second article, the identification of the significative protein bands was done, regarding the relative optic density and frequency. Corticotherapy provoked an alteration in the endometrial proteomics, characterized by an increase and a decrease on the relative optic density and frequency of inflammatory acute phase proteins, with the major alterations observed when corticotherapy was applied in the presence of an infectious process. Streptococcus zooepidemicus infusion provoked alterations in the endometrial fluid proteomics, characterized by an increase and a decrease on the relative optic density and frequency of inflammatory acute phase proteins. Results from this study indicate that corticotherapy provokes immunological alterations in the equine endometrium, not only as depressor, but enhancer of local defense, through an immunomodulatory action. In the third article, the nitric oxide concentration was determined, with no significative diference observed in the four treatments. So, corticotherapy provokes alterations in the proteomics of the endometrial fluid of susceptible mares in estrus, where the presence of an inflammatory stimulus caused by intrauterine bacterial infusion induces a major alteration, than the absence. Uterine lumen infection provokes alterations in the proteomics of the endometrial fluid and corticotherapy does not influence nitric oxide concentration in mares in estrus.

Orientadora: Profª Drª Raquel Vecchio Fornari / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Neurociência e Cognição, 2015. / O objetivo deste trabalho foi avaliar os efeitos da corticosterona na consolidação da memória recente e remota de ratos Wistar submetidos ao condicionamento de medo ao contexto. Os animais receberam 1 choque com duração de 1 segundo e intensidade de 0,6mA durante o treino e, em seguida, foi administrada uma injeção subcutânea de corticosterona nas doses de 0,3mg/kg, 1mg/kg, 3mg/kg ou salina. Os testes ocorreram em 2 dias e em 2 contextos distintos: o contexto do treino e um novo contexto. Os animais foram testados de forma contrabalanceada, ou seja, um grupo passou primeiro pelo contexto do treino enquanto o outro foi testado no novo contexto. No segundo dia, os animais foram testados no contexto oposto ao do primeiro dia, a fim de verificar se a ordem em que eram testados causaria alguma interferência na resposta de congelamento dos animais. Os resultados mostraram que a ordem em que foram expostos aos contextos não exerceu influência na resposta de condicionamento. Os animais testados 48 horas após o treino (memória recente), mostraram discriminar entre o contexto do treino e o novo contexto. Os animais que foram testados 29 dias após o treino (memória remota), apresentaram uma generalização do medo ao contexto. O mesmo grupo de animais que passou pelos testes de memória recente foi re-testado nos dois contextos 26 dias depois. Esses animais conseguiram discriminar entre os dois contextos, sugerindo que as sessões de teste para memória recente podem ter funcionado como sessões de reativação da memória. No entanto, em nenhum dos experimentos foi obtido resultado significativo com as diferentes doses de corticosterona em comparação com os animais do grupo controle. / The aim of this study was to evaluate the effects of corticosterone in the consolidation of recent and remote memory of Wistar rats subjected to contextual fear conditioning. For the 3 minutes training session, the animals received a footshock (1s, 0.6mA) after 2 minutes of free exploration. Immediately after training, the rats received corticosterone subcutaneously at doses of either 0.3mg/kg, 1mg/kg, 3mg/kg or saline. Two days later, the animals were tested in 2 different contexts in a counterbalanced fashion, that is, one group was first tested in the same context of training while the other was presented to a new context. On the second test day, the animals were tested in the opposite context to verify a possible effect of context order in their freezing response. The results showed that the order in which the rats were exposed to the contexts did not interfere with their responses. The animals tested for recent memory, 48 hours after training, discriminated between the training context and the new one. In turn, the animals tested 29 days after training, for remote memory, displayed a generalized fear to both contexts. The same group of animals that had gone through the recent memory test was re-exposed to both contexts 26 days later. The results revealed that these rats were still able to discriminate between the two contexts, suggesting that the recent memory test may have worked as a memory reactivation session. However, no effect of treatment with corticosterone was found in the experiments.