Gegenstand der Dissertationsschrift ist die Untersuchung des Effektes einer Hemmung der Leukotrienbiosynthese auf die Entwicklung des Schädel-Hirn-Traumas (SHT) nach experimenteller fokaler Kontusionsverletzung im Rattenmodell. Die Ergebnisse der Arbeit wurden im Jahre 2011 in einer Publikation veröffentlicht. Das SHT ist eine schwerwiegende globale Erkrankung mit hoher Inzidenz und Mortalität. Diese führt zu hohen Kosten für das Gesundheitssystem, zum einen durch die akute Behandlung im Krankenhaus, zum anderen durch die sich daran anschließenden rehabilitativen Maßnahmen. Nach der primär biomechanischen Verletzung des Hirns, die nicht beeinflussbar ist, bietet die anschließende sekundäre Hirnschädigung aufgrund verschiedener Stoffwechselprozesse Angriffspunkte für eine (medikamentöse) Therapie des SHT. Die sekundären Hirnschäden werden maßgeblich durch die Entwicklung eines perikontusionellen Hirnödems und dem daraus resultierenden Anstieg des intrakraniellen Druckes beeinflusst. Wie in vorangegangenen Untersuchungen gezeigt werden konnte, kam es nach experimentellem SHT zu einem signifikanten Anstieg der Leukotrienwerte im Liquor von Ratten. Dies warf die Frage nach der Rolle der Leukotriene (LT) im posttraumatischen Hirnstoffwechsel bezüglich der Ödementwicklung auf. Ziel dieser Arbeit war der Nachweis einer direkten Beteiligung von Leukotrienen an der sekundären Hirnschädigung und das Aufzeigen eines möglichen therapeutischen Zuganges durch Substitution von Leukotrienbiosynthesehemmern. Dafür wurde bei adulten Ratten ein fokales SHT induziert. Anschließend wurden in zwei Therapiegruppen zwei unterschiedlich wirkende Leukotrieninhibitoren mehrmalig oral verabreicht und die Ausprägung des SHTs nach 24 bzw. 72 Stunden mittels Magnetresonanztomographie (MRT) und immunhistochemischen Aufarbeitung der Hirne mit einer nicht therapierten Kontrollgruppe verglichen. Bei einem dieser LT-Inhibitoren handelte es sich um ein Weihrauchpräparat, das als Nahrungsergänzungsmittel bereits zu erhalten ist und somit auch potentiell am Menschen zur Anwendung kommen kann. Die Ergebnisse waren vielversprechend und zeigten in beiden Therapiegruppen ein verringertes Kontusionsvolumen im MRT und immunhistochemisch einen geringeren Verlust von Neuronen im perikontusionellen Bereich. Somit scheinen Leukotriene einen Anteil an den sekundären Schädigungsprozessen nach SHT zu tragen. Weitere Untersuchungen, vor allem bezüglich eines eventuell verbesserten klinischen Outcome durch Leukotrienbiosynthesehemmung, erscheinen sinnvoll um den potentiellen Einsatz von LT-Synthesehemmstoffen in der Therapie des SHT in Erwägung ziehen zu können.:1. Abkürzungsverzeichnis 2. Bibliographische Beschreibung 3. Einleitung: Schädel-Hirn-Trauma 3.1. Einteilung 3.2. Epidemiologie 3.3 Klinik und Therapie 3.4 Posttraumatisches Hirnödem 3.5 Experimentelles Schädel-Hirn-Trauma 3.6 Leukotriene, MK886 und Boscari 4. Originalpublikation 5. Zusammenfassung der Arbeit 6. Referenzen 7. Anlagen 7.1 Erklärung über die eigenständige Abfassung der Arbeit 7.3 Danksagung

Indiana University-Purdue University Indianapolis (IUPUI) / Type II nephronophthisis (NPHP2) is an autosomal recessive renal cystic disorder characterized by mutations in the inversin gene. Humans and mice with mutations in inversin have enlarged cystic kidneys. Increased kidney size in NPHP2 may involve altered cell growth, apoptosis, electrolyte transport and fluid accumulation in the cysts. To test this hypothesis, histology and transcriptome analysis were performed on one-day old wild-type and inv/inv mice to uncover molecular pathways altered in the mutant mice. Histology of inv/inv mice kidneys showed dilated cystic tubules compared to wild type. Pathway analysis of transcriptome data showed that inversin exerts its effects on kidneys, at least in part, through the transcriptional regulation of genes implicated in inflammation, immune response, cellular metabolism, cell cycle and ion transport. Genes involved in inflammation or immune response were upregulated whereas the genes involved in cell cycle progression and ion transport were downregulated. To validate the array findings from inv/inv mice kidneys, functional consequence of inversin loss on transepithelial ion transport was measured by electrophysiological techniques in shRNA mediated inversin-depleted renal cell type isolated from mouse cortical collecting duct (mCCD). Depletion of inversin decreased vasopressin-induced Na+ absorption, but did not alter Cl- secretion in mCCD cells. Addition of amiloride, a specific blocker of the epithelial sodium channel (ENaC), abolished basal ion transport in both inversin knockdown and control cells indicating ENaC involvement. Loss of inversin decreased Na+ absorption and this effect, in part, was mediated by transcriptional and post-translational regulation of ENaC mediators. To better understand inversin function in renal cells, transcriptome analysis was performed in control and inversin-depleted mCCD cells. Pathway analysis showed that inversin-depletion altered the genes represented in cell cycle, cellular assembly and organization, DNA replication, cell proliferation and ion transport in this isolated renal cell type. In concordance with the array data from inv/inv mice kidneys, a decrease in the expression of cell cycle, ion transport and apoptotic genes were observed accompanied by an upregulation of genes implicated in inflammatory or immune response indicating a direct effect of inversin on renal cells. Together, this study utilized a combination of transcriptome and functional analyses to unravel the role of inversin in renal cells. These data demonstrate that loss of inversin can cause a delay in cell cycle progression with a decrease in cell proliferation and apoptosis which in turn can perturb the development of the renal tubule. Also, a decrease in Na+ reabsorption together with differential regulation of other ion transporters can result in altered electrolyte transport contributing to cystogenesis, cyst growth, fluid accumulation and cyst expansion in NPHP2.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第19273号 / 医博第4037号 / 新制||医||1011(附属図書館) / 32275 / 京都大学大学院医学研究科医学専攻 / (主査)教授 渡邉 大, 教授 村井 俊哉, 教授 高橋 淳 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Introduction: Obsessive-compulsive disorder (OCD) is a complex disorder that is associated with significantly impaired functioning. The current prevailing model of OCD implicates dysfunction of the serotonergic neurotransmitter system and fronto-striatal neural networks, but challenges in replicating findings within OCD samples are often attributed to clinical heterogeneity. OCD symptoms that develop or worsen within the perinatal period appears to reflect a distinct subtype of the disorder, but the genetic and neurobiological factors that contributes to its presentation in women is poorly understood. In this dissertation, we aimed to review the literature on the genetic architecture of OCD, identify potential gene candidates for perinatal OCD and analyze one serotonin system gene according to OCD and possible subtypes using meta-analytic techniques. Based on these findings, we then tested the association of serotonergic candidate gene polymorphisms with the presence of infant-related obsessive-compulsive symptoms (OCS). Lastly, we investigated the cortical morphological features associated with perinatal OCD and OCS symptom severity in postpartum mothers. Results: From prior reports in the literature and our own meta-analytic investigation, polymorphic variants in genes coding for the serotonergic transporter and serotonin 2A receptor subtype (SLC6A4 and HTR2A, respectively) appear to be candidates for perinatal OCD due to their association in female samples. However, upon investigation in our perinatal sample (n=107), we found no evidence to support the association of the 5-HTTLPR polymorphism of SLC6A4 with perinatal-related OCS, but larger samples are needed to confirm this finding. Due to technical challenges, the HTR2A polymorphism remains to be tested. Our novel whole-brain explorations revealed distinct cortical morphology associated with symptom worsening across the perinatal period, irrespective of diagnosis. Cortical parameters were not able to differentiate mothers with and without OCD; however, OCD mothers displayed positive correlations between cortical surface area and symptom severity in widespread regions, including the frontal, parietal, temporal and occipital cortex. Conclusions: Overall, this body of work aimed to fill the gap in the literature by exploring the possible genetic and cortical correlates of perinatal-related OCS and OCD. While 5-HTTLPR or HTR2A are candidates for perinatal OCD, it is not yet clear whether they increase susceptibility for the development of infant-related OCS in the perinatal period. Distinct cortical alterations in surface area appeared alongside OCS exacerbation in the postpartum period in regions that extend beyond the frontoparietal network. This suggests that additional neural networks may be contributing to symptom severity and that the cortical plasticity that occurs across the perinatal period may predispose women for risk of OCD. Future studies should continue to use a multiple perspective approach, that utilizes genetic and neurobiological techniques, in order to provide greater insight into the etiology of perinatal OCD. / Dissertation / Doctor of Philosophy (PhD) / Women are at greater risk for the development of mental illness in the time surrounding pregnancy and postpartum, known as the perinatal period. In the case of perinatal obsessive-compulsive disorder (OCD), mothers may experience unique worries in regard to their parenting or fears that their baby may be harmed. While these worries are common, they can become disruptive when persistent and impact the mother’s mood and ability to bond with the infant. Our current understanding of OCD includes the influence of genetic factors and brain changes, but little is understood about what factors may increase risk for OCD in the perinatal period. In this thesis, we aimed to review whether certain alterations within DNA segments, known as gene variants, may be linked to the development of OCD in females and if these gene changes, as well as differences in brain structures in postpartum mothers, are associated with OCD symptoms during the perinatal period. The genes we examined are important for regulating a chemical signaling substance in the brain known as serotonin. Based on our results, we did not find a relationship between serotonin gene variants and OCD symptoms in perinatal women. We also found no differences when comparing the cortical brain structures between mothers with OCD and healthy mothers; however, we observed that measures of surface area across several cortical brain regions were related to symptom worsening from pregnancy to postpartum, and also with symptom severity in postpartum mothers with OCD. These results suggest that there are widespread brain changes during the postpartum period that may increase a mother’s risk for developing OCD. Overall, the work in this thesis provides the first glimpse into potential risk factors for perinatal OCD.

During the epithelial-to-mesenchymal transition, the intracellular cytoskeleton undergoes severe reorganization which allows epithelial cells to transition into a motile mesenchymal phenotype. Among the different cytoskeletal elements, the intermediate filaments keratin (in epithelial cells) and vimentin (in mesenchymal cells) have been demonstrated to be useful and reliable histological markers. In this study, we assess the potential invasiveness of six human breast carcinoma cell lines and two mouse fibroblasts cells lines through single cell migration assays in confinement. We find that the keratin and vimentin networks behave mechanically the same when cells crawl through narrow channels and that vimentin protein expression does not strongly correlate to single cells invasiveness. Instead, we find that what determines successful migration through confining spaces is the ability of cells to mechanically switch from a substrate-dependent stress fibers based contractility to a substrate-independent cortical contractility, which is not linked to their tumor phenotype.

Because event-related potentials (ERPs) can reflect individual differences in intellectual ability, individual differences in college grade-point average (GPA) may be associated with specific individual ERP waves, such as the P300. However, P300 amplitude is higher in women than in men and varies across the menstrual cycle, factors that could confound the association between GPA and ERPs. In this regard, our objective was to determine whether differences in GPA are reflected in ERPs while standardling for sex and menstrual phase. After participants provided informed consent, we obtained GPAs from 22 right-handed college students (11 male, age range 22 to 26 and 10 female, age range 17 to 24) at a university with high admission and retention standards. We assessed menstrual phase by measuring luteinizing hormone levels across the cycle. We then obtained ERPs for each male participant and ERPs during each phase of the menstrual cycle for each female participant in an object-recognition visual pop-out protocol using Net Station Software (Electrical Geodesics, Inc., Eugene, Oregon) and E-prime Software (Psychology Software Tools, Inc., Sharpsburg, Pennsylvania). Males had larger P300s than females. The male and female high GPA was significantly different from the low GPA male and female groups. High GPA in females and males were associated with a positive peak at approximately 689 ms that was not present in the low-GPA male group and was significantly diminished in low-GPA females. Electro-cortical processing of cognitive stimuli differs between college students with high and low GPAs.

Finding neural correlates of intelligence and cognitive abilities in the developing brain during childhood may be important in many ways, such as predicting and understanding educational abilities or making clinical evaluations of patients. Even if substantial contemporary research has established relationships between brain structures and general intelligence, little is known about the lingual gyri and their links to IQ. In this thesis it is examined (1) whether cortical thickness in the right and left lingual gyri is associated with different levels of IQ in childrenand (2) if the rate of change in cortical thickness located in the lingual gyri is associated with change in Performance IQ (PIQ). Neuroimaging data originated from a study by Solé-Casals and colleagues (2019) as well as a dataset from a study by Suárez-Pellicioni and colleagues(2019). Both datasets were downloaded from the OpenNeuro library of brain imaging data. Neuroimaging metrics of twenty-nine boys of approximately twelve years of age were utilizedto test the hypothesis that higher IQ is related to thinner cortical thickness in lingual gyri. Neuroimaging metrics of twenty-one girls and fifteen boys under fourteen years of age utilized to examine if the rate of change in cortical thickness is related to a change in Performance IQ.Results revealed that high IQ was related to thinner cortical thickness at the age of twelve. Further results indicated that rate of thinning of the cortex in the lingual gyri is correlated to change in Performance IQ. The present thesis adds to the growing evidence that regional cortical thickness and change of cortical thickness are relevant biomarkers for intelligence. Future research with larger sample sizes and longitudinal design with additional points in timemight be needed to confirm the results of the present thesis.

Individuals diagnosed with autism spectrum disorder often experience difficulty during speech-in-noise (SIN) processing tasks. However, it remains unclear how behavioral and cortical mechanisms of auditory processing explain variability in SIN performance in adults with ASD and their neurotypical counterparts. The proposed research explored variability in SIN as it relates to behavioral, perceptual, and objective measures of auditory processing. Results showed significant differences between groups in SIN thresholds. In addition, neurotypicals outperformed the ASD group on measures of sustained auditory attention characterized by reduced impulsivity, increased inhibition, and increased selective auditory attention. Individuals with ASD showed decreased acceptance of noise as compared to neurotypical peers. Overall, results highlighted auditory processing deficits in individuals with ASD that contribute to SIN performance.

Le sommeil s’avère crucial pour le bien-être de l’organisme. En particulier, le sommeil est une période privilégiée pour le maintien et la plasticité du cortex. En outre, de nombreuses études ont démontré son importance dans les processus de mise à l’échelle des synapses neuronales, la consolidation mnésique, la régularisation des émotions ainsi que la performance cognitive. La période et la structure du sommeil sont gouvernées par deux processus, soit la pression homéostatique et le rythme circadien. Le rythme circadien endogène, généré par le noyau suprachiasmatique de l’hypothalamus, se maintient synchronisé au rythme jour-nuit environnemental par l’information photique provenant des cellules ganglionnaires intrinsèquement photoréceptrices de la rétine. Par conséquent, la lumière et le fonctionnement de la rétine s’avèrent importants pour le maintien du rythme circadien et, en conséquence, le sommeil. De ce fait, il n’est pas surprenant que la cécité soit reliée à une plus grande fréquence de troubles du sommeil. Ceux-ci proviennent, du moins en partie, de rythmes circadiens non-synchronisés ou en libre cours causé par l’absence d’information photique. La cécité induit aussi une modulation anatomique et fonctionnelle du cortex, en particulier dans les aires visuelles. Cette réorganisation corticale peut, donc, aussi moduler l’activité corticale lors de l’état de sommeil. Les études, qui font l’objet de cette présente thèse, visent à investiguer les effets de la cécité sur la période et la structure du sommeil. En particulier, des données comportementales et physiologiques furent comparées entre un groupe de participants avec cécité, ne reportant aucune perception visuelle résiduelle, et un groupe contrôle de participants ayant une vision normale. La cécité était d’origine congénitale chez la moitié des participants et elle fut acquise plus tard dans la vie chez les autres participants aveugles. Les présentes études rapportent sur la qualité de leur sommeil, le rythme éveil-sommeil, la phase du rythme circadien, ainsi que la macro- et microstructure de leur sommeil. En lien avec les études antérieures, les aveugles démontrent une plus grande fréquence de phases anormales du rythme circadien, de troubles du sommeil et de déstabilisation du rythme éveil-sommeil. De plus, bien que la structure du sommeil demeure généralement présente en absence de vision, certaines modulations électrophysiologiques furent observées. En particulier, des différences dans l’activité corticale lors du sommeil NREM observées entre les aveugles congénitaux et les aveugles tardifs suggèrent que la réorganisation corticale, provenant de la perte de vision, peut être observée lors du sommeil. De plus, la modulation des aires corticales visuelles associée avec la cécité résulte en une absence de certaines composantes caractéristiques des différents stades du sommeil. Notamment, l’oscillation occipitale de fréquence alpha observée lors d’un état de repos et lors de l’endormissement se voit absente chez les aveugles. Les résultats démontrent que la modulation du rythme circadien ainsi que la réorganisation corticale associée avec la cécité agissent sur la période et la structure caractéristique du sommeil. / Sleep is a crucial state for the wellbeing of humans. More specifically, sleep is a privileged period for cortical maintenance and plasticity. Accordingly, numerous studies have demonstrated the importance of sleep in synaptic downscaling processes, memory consolidation, emotional regulation, as well as cognitive performance. The timing and structure of sleep is shown to be governed by two main processes: the homeostatic pressure and the circadian rhythm. In turn, the endogenous circadian rhythm, produced by the suprachiasmatic nucleus of the hypothalamus, is entrained to the day-night environmental cycle by photic input from the intrinsically photoreceptive retinal ganglion cells. Thus, light is necessary for the proper entrainment of the circadian rhythm, and consequently, for sleep. It is, therefore, not surprising that blindness is associated with a greater incidence of sleep disturbances. Specifically, these disturbances can be, in part, explained by abnormal or free-running circadian rhythms resulting from the absence of photic input. Further, absence of visual input also induces anatomical and functional changes throughout the brain, and specifically in the visual cortical areas. Such cortical reorganisation could, potentially, also modulate the cortical activity of sleep. The studies that compose the present thesis aim to expand upon the effects of blindness on the timing and structure of sleep. Specifically, both behavioural and physiological data were collected and compared between a group of blind participants, reporting no conscious light perception, and a control group of normal sighted participants. In the blind group, half of the participants were born blind, while the other half had acquired blindness later in life. The studies report on the various components of sleep, including its quality, the sleep-wake rhythm, the phase of the circadian rhythm, as well as its macro- and microstructure. In line with previous studies, a larger incidence of abnormal circadian phase, sleep disturbances, and reduced sleepiv wake stability were observed in the blind group. Further, although the macro- and microstructure of sleep remains generally present in the absence of vision, certain electrophysiological differences were, nevertheless, observed. Differences in NREM cortical activity observed between the congenitally and late blind participants suggest that the cortical reorganisation associated with the absence of vision may be detected through electrophysiological recordings of sleep. Further, modulations of cortical activity in blindness also resulted in the absence of certain characteristics of the different stages of sleep. Namely, occipital alpha oscillations, typically observed during a quiet resting state and in the transition from wake to sleep, are absent in blind individuals. These results, therefore, demonstrate that both the circadian rhythm abnormalities and the cortical reorganisation that is associated with the absence of vision can influence both the timing and the structure of sleep in blind individuals.

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