Recent Genome Wide Association Studies (GWAS) have identified a series of single nucleotide polymorphism (SNP)s that are associated with Alzheimer’s disease (AD). One of the SNPs, rs3851179 (G/A), is near the gene phosphatidylinositol-binding clathrin assembly protein (PICALM). To evaluate whether this SNP is associated with PICALM expression, we quantified PICALM mRNA in 56 brain cDNA samples. Using linear regression analysis, we analyzed PICALM expression relative to rs3851179, AD status, and cell type specific markers. An association was detected between rs3851179 and PICALM, microvessel mRNA, glial fibrillary acidic protein (GFAP) mRNA, and synaptophysin (SYN) mRNA. To gain clarity into other possible SNP mechanisms, we searched brain cDNA for PICALM splice variants. We identified several PICALM splice variants involving exons 13-19. To identify and gain an estimation of relative abundance of splice variants, we PCR-amplified across exons 13-20 in cDNA from six individuals, three rs3851179 GG individuals and three rs3851179 AA individuals. Sequencing the cloned isoforms we found that PICALM lacking exon 13 (delta 13) is the most abundant isoform. Other isoforms detected included deletion of exon 18-19. We targeted the latter part of the gene, exon 17-20, to investigate unequal allelic expression using next generation sequencing. Individuals heterozygous for rs76719109 (n= 35), located in exon 17, were used to study the abundance of G/T allele in cDNA and genomic DNA. When we analyzed the T:G allelic ratio, the variant lacking exons 18 and 19 showed unequal allelic expression (p-value < 0.001) in a subset of individuals. One individual was an outlier, showing overall unequal allelic expression, which maybe be harboring a rare mutation capable of modifying PICALM expression. The PICALM intronic SNP rs588076 was associated with delta 18-19 isoform splicing (p-value < 0.001). In conclusion, this study gained a greater insight into the role of AD genetics in PICALM expression and splicing.

The diffusible soluble oligomeric amyloid β-peptide (Aβ) has been identified as a toxic agent in Alzheimer’s disease that can cause synaptic dysfunction and memory loss, indicating its role as potential therapeutic targets for AD treatment. Recently an oligomer-specific sandwich biotin-avidin interaction based assay identified the Aβ oligomer dissociation potency of a series of dihydroxybenzoic acid (DHBA) isomers. Because the sandwich assay is an ensemble method providing limited size information, fluorescence correlation spectroscopy (FCS) was employed to provide single molecule resolution of the disassembly mechanism. Using FCS coupled with atomic force microscopy, we investigated the size distribution of fluorescein labeled synthetic Aβ oligomers at physiological concentrations, and monitored in real time the change of size and mole fraction of oligomers in the presence of dissociating agents or conditions. The higher-order dissociation process caused by DHBA isomers produced no transient oligomeric intermediates, a desirable feature for an anti-oligomer therapeutic. Urea and guanidine hydrochloride, in contrast, produced a linear dissociation with a progressive decrease of size and mole fraction of oligomers. FCS allows the facile distinction of small molecule Aβ oligomer dissociators that do not produce stable potentially toxic oligomeric Aβ intermediates.

Quantitative magnetic resonance imaging (MRI) was used to assess global and regional cerebral volumes in patients with a clinical diagnosis of subcortical vascular dementia (VD) and Alzheimer’s disease (AD). Whole brain volume, cerebrospinal fluid volume, volumes of the temporal, frontal and parietal lobes, the cerebellum and the amygdala-hippocampus complex were determined using a personal computer-based software. Seventeen patients with VD, 22 patients with AD and 13 healthy controls were included. Analysis of covariance using age as covariate demonstrated significant mean differences between controls and dementia groups with respect to all morphological parameters. However, apart from the volume of the cerebellum no significant volumetric differences were found between VD and AD. These results indicate that MRI-based volumetry allows differentiation between AD or VD from normal controls and that measurement of cerebellar volume may be of use to separate vascular and degenerative dementia. However, since the distribution of cerebral atrophy in both dementia groups is very similar, it is suggested that the atrophic changes are not specific to the underlying cause but rather reflect the selective vulnerability of neuronal structures. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Aujourd’hui, malgré la description des mécanismes à l’origine du développement de la dépression et de la MA, aucun traitement curatif n’existe pour ces pathologies suggérant l’implication d’un autre phénomène. L’un des processus retrouvé communément dans ces pathologies est la neuroinflammation. Or pour le moment, les essais cliniques entrepris dans la MA afin de réduire la neuroinflammation n’ont pas permis d’aboutir à une amélioration significative des symptômes. L’une des raisons de cet échec serait une mauvaise fenêtre thérapeutique qui aurait pour conséquence d’exacerber les effets délétères de la neuroinflammation. Ceci met en lumière la méconnaissance de la cinétique de la neuroinflammation dans la MA. Ainsi notre travail de thèse avait pour but, d’une part, d’étudier l’impact d’anti-inflammatoires comparativement à celui d’antidépresseur dans la dépression chez la souris, et d’autre part, d’étudier l’impact de l’utilisation d’antidépresseur et d’anti-inflammatoires dans un modèle murin de MA. / Today, despite the description of the mechanisms underlying the development of depression and AD (Alzheimer’s disease), no cure exists for these diseases suggesting the involvement of another phenomenon. One of the processes commonly found in these pathologies is neuroinflammation. However, clinical trials undertaken in the AD to reduce neuroinflammation have not led to a significant improvement of symptoms. One reason for this failure could be a bad therapeutic window which would result in the increase of deleterious effects of neuroinflammation. This highlights the lack of understanding of the kinetics of neuroinflammation in AD.

Infectious and neurodegenerative diseases continue to be a major concern worldwide. In spite of the great advances in drug therapy for treating various infectious and neurodegenerative diseases, there is still an urgent need for new and improved drugs due to increasing drug resistance among pathogens, emergence of new pathogens, ease of transmission of infections, ineffective available treatments, toxicity associated with current standard of care, aging populations and the lack of better alternative treatment options. The first part of this manuscript (chapters 1 - 5) describes the synthesis of novel agents active against Leishmania donovani. According to the World Health Organization (WHO), a significant number of deaths worldwide can be attributed to infectious diseases – particularly neglected tropical diseases (NTDs), one of which is leishmaniasis - a complex and clinically diverse disease transmitted through the bite of an infected female phlebotomine sand-fly. The pathogen that causes leishmaniasis develops through a complex life cycle via different morphological changes. Its clinical presentations range from the less severe (cutaneous) to lethal/fatal (visceral) forms depending upon the level of systemic involvement, infecting species and the endemic environment. Treatments (and vaccines) must be species-specific to be particularly effective since sensitivity to commonly used drugs is largely species-specific. Heat shock protein 90 (Hsp 90) has been shown to promote the differentiation of the protozoan parasite that causes leishmaniasis from the promastigote stage to the amastigote pathogenic stages. To this end a series of compounds were prepared based on known Hsp 90 inhibitors, SNX2112 and XL888. The synthetic approach allows the probing of a hydrophobic pocket and rapid access to a collection of anti-leishmanial compounds. The most active compound, was found to be more than twice as active as the climivally used drug, miltefosine, in an infected J774 macrophage at IC50 = 0.65 µM. The second part of this manuscript (chapters 6 - 9) describes the synthesis novel anti-Alzheimer’s agents. Alzheimer’s disease is a progressive neurodegenerative disease believed to be caused by tau hyperphosphorylation and plaque aggregation in the brain. It is known to affect about 44 million people worldwide and it is marked as the 6th leading cause of death in the United States. Slingshot homology-1 (SSH1) proteins, important protein phosphatases, are promising targets for the discovery of a new generation of small molecule inhibitors as treatment for Alzheimer’s disease, since SSH1 is known to contribute to both tau hyperphosphorylation and plaque aggregation in the brain. Through structure and activity relationships (SAR) studies, two (2) series of compounds were synthesized, thiazoles and pyridones, bearing a carboxylic acid or phosphonic acid functionality as inhibitors of SSH1 enzymes. In the preliminary screening efforts against SSH1 phosphatase activity, the thiazole series were found to be more potent at inhibiting the phosphatase activity than the pyridone series. Among the active thiazole series, eight (8) analogs exhibited significant inhibitory activity over the initial hit compound, observed via phosphatase inhibition curves (using a pNPP phosphatase assay). Further investigations into the molecular target (SSH1) are currently underway.

Introdução: A Doença de Alzheimer (DA) é uma desordem neurodegenerativa e a forma mais comum de demência. Processos inflamatórios parecem desempenhar importante papel na fisiopatologia da DA. A neuroinflamação é caracterizada pela ativação da microglia e a liberação de citocinas inflamatórias, tais como IL-1β, IL-6 e TNF-α. Porém, não se sabe qual é a real contribuição destes marcadores inflamatórios no desenvolvimento da DA. Objetivos: A proposta deste estudo é avaliar a possível relação entre marcadores inflamatórios no liquido cefalorraquidiano de indivíduos com comprometimento cognitivo leve amnéstico (CCL-a), com 60 anos ou mais, e comparar com controles saudáveis da mesma faixa etária. Métodos: Foram examinadas as concentrações de IL-1β, IL-6 e TNF-α no líquido cefalorraquidiano de sujeitos com CCL-a e em controles pelo método ELISA. Diagnósticos de CCL-a foram baseados na anamnese e nos critérios de Petersen, corroborados pela escala CDR. Para avaliar a função cognitiva o teste de memória e reconhecimento de palavras do CERAD e o Teste do Relógio foram aplicados aos participantes. Para a avaliação de sintomas depressivos usou-se o GDS. Resultados: Este estudo demonstrou diminuição significativa nos níveis de IL-1β (13.735 vs 22.932 pg/mL; p <0.001) e TNF-α (1.913 vs 2.627 pg/mL; p: 0.002), mas não nos níveis da IL-6 (4.178 vs 5.689 pg/mL; p: 0.106), entre casos e controles. Indivíduos com IL-1β < 17 pg/mL possuem 7.2 (CI: 1.5-36; p: 0.016) mais chances de evoluírem à CCL-a. Além disso, houve correlação positiva entre IL-1β e a pontuação da lista de palavras do CERAD (rs: 0.299; p: 0.046). A análise de regressão linear mostrou que os níveis de IL-1β podem explicar 13.7% (β: 24.545; p: 0.012) da variância da pontuação do CERAD, o que sugere uma dependência linear direta. Conclusões: A neuroinflamação, mediada pela IL-1β e pelo TNF-α, provavelmente possui importante papel na prevenção de CCL-a. / Introduction: Alzheimer Disease (AD) is a neurodegenerative disorder and the most common form of dementia. Inflammatory processes may play a significant role at the pathophysiology of AD. Neuroinflammation is characterized by activation of microglia and the release of inflammatory cytokines, such as IL-1β, IL-6 and TNF-α. Although, it is unknown what is the real contribution of these inflammatory markers in the development of AD. Aims: The purpose of this study is to assess the possibly relationship between inflammatory markers in CSF of amnestic MCI subjects, with sixty years or older, and compare to aged healthy controls. Methods: We examined concentrations of IL-1β, IL-6 and TNF-α at CSF of amnestic MCI subjects and controls by ELISA. MCI diagnoses were based on anamnesis and Petersen criteria, corroborated by CDR. To assess the cognitive function the word list memory test and word recognition of CERAD and Clock Drawing Test were applied to subjects, and to evaluated depression symptoms the GDS was used. Results: This study demonstrated significant diminish in the levels of IL-1β (13.735 vs 22.932 pg/mL; p <0.001) and TNF-α (1.913 vs 2.627 pg/mL; p: 0.002), but not IL-6 (1.913 vs 2.627 pg/mL; p: 0.002), between cases and controls. Individuals with IL-1β < 17 pg/mL were at a 7.2 (CI: 1.5-36; p: 0.016) increased odds of aMCI. Furthermore, there was a positive correlation between IL-1β and the CERAD word list score (rs: 0.299; p: 0.046). The linear regression analysis showed that IL-1β levels can explain 13.7% (β: 24.545; p: 0.012) of the variance on this CERAD subscore, suggesting a direct linear dependence. Conclusion: Neuroinflamation mediated by IL-1β and TNF-α may play an important role in preventing aMCI.

No description available.

Introdução: A Doença de Alzheimer (DA) é uma desordem neurodegenerativa e a forma mais comum de demência. Processos inflamatórios parecem desempenhar importante papel na fisiopatologia da DA. A neuroinflamação é caracterizada pela ativação da microglia e a liberação de citocinas inflamatórias, tais como IL-1β, IL-6 e TNF-α. Porém, não se sabe qual é a real contribuição destes marcadores inflamatórios no desenvolvimento da DA. Objetivos: A proposta deste estudo é avaliar a possível relação entre marcadores inflamatórios no liquido cefalorraquidiano de indivíduos com comprometimento cognitivo leve amnéstico (CCL-a), com 60 anos ou mais, e comparar com controles saudáveis da mesma faixa etária. Métodos: Foram examinadas as concentrações de IL-1β, IL-6 e TNF-α no líquido cefalorraquidiano de sujeitos com CCL-a e em controles pelo método ELISA. Diagnósticos de CCL-a foram baseados na anamnese e nos critérios de Petersen, corroborados pela escala CDR. Para avaliar a função cognitiva o teste de memória e reconhecimento de palavras do CERAD e o Teste do Relógio foram aplicados aos participantes. Para a avaliação de sintomas depressivos usou-se o GDS. Resultados: Este estudo demonstrou diminuição significativa nos níveis de IL-1β (13.735 vs 22.932 pg/mL; p <0.001) e TNF-α (1.913 vs 2.627 pg/mL; p: 0.002), mas não nos níveis da IL-6 (4.178 vs 5.689 pg/mL; p: 0.106), entre casos e controles. Indivíduos com IL-1β < 17 pg/mL possuem 7.2 (CI: 1.5-36; p: 0.016) mais chances de evoluírem à CCL-a. Além disso, houve correlação positiva entre IL-1β e a pontuação da lista de palavras do CERAD (rs: 0.299; p: 0.046). A análise de regressão linear mostrou que os níveis de IL-1β podem explicar 13.7% (β: 24.545; p: 0.012) da variância da pontuação do CERAD, o que sugere uma dependência linear direta. Conclusões: A neuroinflamação, mediada pela IL-1β e pelo TNF-α, provavelmente possui importante papel na prevenção de CCL-a. / Introduction: Alzheimer Disease (AD) is a neurodegenerative disorder and the most common form of dementia. Inflammatory processes may play a significant role at the pathophysiology of AD. Neuroinflammation is characterized by activation of microglia and the release of inflammatory cytokines, such as IL-1β, IL-6 and TNF-α. Although, it is unknown what is the real contribution of these inflammatory markers in the development of AD. Aims: The purpose of this study is to assess the possibly relationship between inflammatory markers in CSF of amnestic MCI subjects, with sixty years or older, and compare to aged healthy controls. Methods: We examined concentrations of IL-1β, IL-6 and TNF-α at CSF of amnestic MCI subjects and controls by ELISA. MCI diagnoses were based on anamnesis and Petersen criteria, corroborated by CDR. To assess the cognitive function the word list memory test and word recognition of CERAD and Clock Drawing Test were applied to subjects, and to evaluated depression symptoms the GDS was used. Results: This study demonstrated significant diminish in the levels of IL-1β (13.735 vs 22.932 pg/mL; p <0.001) and TNF-α (1.913 vs 2.627 pg/mL; p: 0.002), but not IL-6 (1.913 vs 2.627 pg/mL; p: 0.002), between cases and controls. Individuals with IL-1β < 17 pg/mL were at a 7.2 (CI: 1.5-36; p: 0.016) increased odds of aMCI. Furthermore, there was a positive correlation between IL-1β and the CERAD word list score (rs: 0.299; p: 0.046). The linear regression analysis showed that IL-1β levels can explain 13.7% (β: 24.545; p: 0.012) of the variance on this CERAD subscore, suggesting a direct linear dependence. Conclusion: Neuroinflamation mediated by IL-1β and TNF-α may play an important role in preventing aMCI.

Introdução: A Doença de Alzheimer (DA) é uma desordem neurodegenerativa e a forma mais comum de demência. Processos inflamatórios parecem desempenhar importante papel na fisiopatologia da DA. A neuroinflamação é caracterizada pela ativação da microglia e a liberação de citocinas inflamatórias, tais como IL-1β, IL-6 e TNF-α. Porém, não se sabe qual é a real contribuição destes marcadores inflamatórios no desenvolvimento da DA. Objetivos: A proposta deste estudo é avaliar a possível relação entre marcadores inflamatórios no liquido cefalorraquidiano de indivíduos com comprometimento cognitivo leve amnéstico (CCL-a), com 60 anos ou mais, e comparar com controles saudáveis da mesma faixa etária. Métodos: Foram examinadas as concentrações de IL-1β, IL-6 e TNF-α no líquido cefalorraquidiano de sujeitos com CCL-a e em controles pelo método ELISA. Diagnósticos de CCL-a foram baseados na anamnese e nos critérios de Petersen, corroborados pela escala CDR. Para avaliar a função cognitiva o teste de memória e reconhecimento de palavras do CERAD e o Teste do Relógio foram aplicados aos participantes. Para a avaliação de sintomas depressivos usou-se o GDS. Resultados: Este estudo demonstrou diminuição significativa nos níveis de IL-1β (13.735 vs 22.932 pg/mL; p <0.001) e TNF-α (1.913 vs 2.627 pg/mL; p: 0.002), mas não nos níveis da IL-6 (4.178 vs 5.689 pg/mL; p: 0.106), entre casos e controles. Indivíduos com IL-1β < 17 pg/mL possuem 7.2 (CI: 1.5-36; p: 0.016) mais chances de evoluírem à CCL-a. Além disso, houve correlação positiva entre IL-1β e a pontuação da lista de palavras do CERAD (rs: 0.299; p: 0.046). A análise de regressão linear mostrou que os níveis de IL-1β podem explicar 13.7% (β: 24.545; p: 0.012) da variância da pontuação do CERAD, o que sugere uma dependência linear direta. Conclusões: A neuroinflamação, mediada pela IL-1β e pelo TNF-α, provavelmente possui importante papel na prevenção de CCL-a. / Introduction: Alzheimer Disease (AD) is a neurodegenerative disorder and the most common form of dementia. Inflammatory processes may play a significant role at the pathophysiology of AD. Neuroinflammation is characterized by activation of microglia and the release of inflammatory cytokines, such as IL-1β, IL-6 and TNF-α. Although, it is unknown what is the real contribution of these inflammatory markers in the development of AD. Aims: The purpose of this study is to assess the possibly relationship between inflammatory markers in CSF of amnestic MCI subjects, with sixty years or older, and compare to aged healthy controls. Methods: We examined concentrations of IL-1β, IL-6 and TNF-α at CSF of amnestic MCI subjects and controls by ELISA. MCI diagnoses were based on anamnesis and Petersen criteria, corroborated by CDR. To assess the cognitive function the word list memory test and word recognition of CERAD and Clock Drawing Test were applied to subjects, and to evaluated depression symptoms the GDS was used. Results: This study demonstrated significant diminish in the levels of IL-1β (13.735 vs 22.932 pg/mL; p <0.001) and TNF-α (1.913 vs 2.627 pg/mL; p: 0.002), but not IL-6 (1.913 vs 2.627 pg/mL; p: 0.002), between cases and controls. Individuals with IL-1β < 17 pg/mL were at a 7.2 (CI: 1.5-36; p: 0.016) increased odds of aMCI. Furthermore, there was a positive correlation between IL-1β and the CERAD word list score (rs: 0.299; p: 0.046). The linear regression analysis showed that IL-1β levels can explain 13.7% (β: 24.545; p: 0.012) of the variance on this CERAD subscore, suggesting a direct linear dependence. Conclusion: Neuroinflamation mediated by IL-1β and TNF-α may play an important role in preventing aMCI.

Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-10-18T19:17:10Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertacao -Gilderlanio Santana de Araujo.pdf: 9533988 bytes, checksum: 951b1cf090729a87ebf3a8741ff00ad4 (MD5) / Made available in DSpace on 2016-10-18T19:17:10Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertacao -Gilderlanio Santana de Araujo.pdf: 9533988 bytes, checksum: 951b1cf090729a87ebf3a8741ff00ad4 (MD5) Previous issue date: 2013-03-07 / FACEPE / O desenvolvimento de técnicas de genotipagem de baixo custo (SNP arrays) e as anotações de milhares de polimorfismos de nucleotídeo único (SNPs) em bancos de dados públicos têm originado um crescente número de estudos de associação em escala genômica (do inglês, Genome-Wide Associations Studies - GWAS). Nesses estudos, um enorme número de SNPs (centenas de milhares) são avaliados com métodos estatísticos univariados de forma a encontrar SNPs associados a um determinado fenótipo. Testes univariados são incapazes de capturar relações de alta ordem entre os SNPs, algo comum em doenças genéticas complexas e são afetados pela alta correlação entre SNPs na mesma região genômica. Métodos de aprendizado de máquina, como o Random Forest (RF), têm sido aplicados em dados de GWAS para realizar a previsão de riscos de doenças e capturar os SNPs associados às mesmas. Apesar de RF ser um método com reconhecido desempenho em dados de alta dimensionalidade e na captura de relações não-lineares, o uso de todos os SNPs presentes em um estudo GWAS é computacionalmente inviável. Neste estudo propomos o uso de redes biológicas para a seleção inicial de SNPs candidatos a serem usados pela RF. A partir de um conjunto inicial de genes já relacionados à doença na literatura, usamos ferramentas de redes de interação gene-gene, para encontrar novos genes que possam estar associados a doença. Logo, é possível extrair um número reduzido de SNPs tornando a aplicação do método RF viável. Os experimentos realizados nesse estudo concentram-se em investigar quais polimorfismos podem influenciar na suscetibilidade à doença de Alzheimer (DA) e ao comprometimento cognitivo leve (MCI). O resultado final das análises é a delineação de uma metodologia para o uso de RF, para a análise de dados de GWAS, assim como a caracterização de potenciais fatores de riscos da DA. / The development of low cost genotyping techniques (SNP arrays) and annotations of thousands of single nucleotide polymorphisms (SNPs) in public databases has led to an increasing number of Genome-Wide Associations Studies (GWAS). In these studies, a large number of SNPs (hundreds of thousands) are evaluated with univariate statistical methods in order to find SNPs associated with a particular phenotype. Univariate tests are unable to capture high-order relationships among SNPs, which are common in complex genetic diseases, and are affected by the high correlation between SNPs at the same genomic region. Machine learning methods, such as the Random Forest (RF), have been applied to GWAS data to perform the prediction of the risk of diseases and capture a set of SNPs associated with them. Although, RF is a method with recognized performance in high dimensional data and capacity to capture non-linear relationships, the use of all SNPs present in GWAS data is computationally intractable. In this study we propose the use of biological networks for the initial selection of candidate SNPs to be used by RF. From an initial set of genes already related to a disease based on the literature, we use tools for construct gene-gene interaction networks, to find novel genes that might be associated with disease. Therefore, it is possible to extract a small number of SNPs making the method RF feasible. The experiments conducted in this study focus on investigating which polymorphisms may influence the susceptibility of Alzheimer’s disease (AD) and mild cognitive impairment (MCI). This work presents a delineation of a methodology on using RF for analysis of GWAS data, and characterization of potential risk factors for AD.