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<p>Developmental toxicology is an important part of preclinical drug toxicology as well as environmental toxicology. Assessing reproductive and developmental toxicity is especially expensive and time demanding, since at least two generations of animals are needed in the tests. In light of this there is a great need for alternative test methods in many areas of developmental toxicity testing.</p><p>The complete set of RNA transcripts in any given organism is called the transcriptome. Proteomics refers to the study of the proteins in a given organism or cell population. The work of this thesis has focused on the use of high throughput screening methods in transcriptomics and proteomics to search for molecular markers of developmental toxicity.</p><p>We have studied the global gene expression effects of the developmentally toxic substance valproic acid (VPA) using microarray technology. Several genes were found that display the same gene expression pattern <i>in vivo</i> using mouse embryos as the pattern seen <i>in vitro</i> using the embryocarcinoma cell line P19. Based on these observations, the gene Gja1 was suggested as one potential molecular marker of VPA induced developmental toxicity and potential marker of histone deacetylase (HDAC) inhibition <i>in vitro</i>. </p><p>Using 2D-DIGE technology, which measures relative protein abundances, the effect of neonatal exposure to the flame retardant PBDE-99 was studied in mouse brain (cortex, hippocampus and striatum) 24 hr after exposure. Differentially expressed proteins in the cortex and the striatum indicate that PBDE-99 may alter neurite outgrowth.</p><p>Finally, we have suggested several improvements in the use of the 2D-DIGE technology. Novel methods for normalizing data were presented, with several advantages compared to existing methods. We have presented a method named DEPPS that makes use of all identified proteins in a dataset to make comprehensive remarks about biological processes affected.</p>

Developmental toxicology is an important part of preclinical drug toxicology as well as environmental toxicology. Assessing reproductive and developmental toxicity is especially expensive and time demanding, since at least two generations of animals are needed in the tests. In light of this there is a great need for alternative test methods in many areas of developmental toxicity testing. The complete set of RNA transcripts in any given organism is called the transcriptome. Proteomics refers to the study of the proteins in a given organism or cell population. The work of this thesis has focused on the use of high throughput screening methods in transcriptomics and proteomics to search for molecular markers of developmental toxicity. We have studied the global gene expression effects of the developmentally toxic substance valproic acid (VPA) using microarray technology. Several genes were found that display the same gene expression pattern in vivo using mouse embryos as the pattern seen in vitro using the embryocarcinoma cell line P19. Based on these observations, the gene Gja1 was suggested as one potential molecular marker of VPA induced developmental toxicity and potential marker of histone deacetylase (HDAC) inhibition in vitro. Using 2D-DIGE technology, which measures relative protein abundances, the effect of neonatal exposure to the flame retardant PBDE-99 was studied in mouse brain (cortex, hippocampus and striatum) 24 hr after exposure. Differentially expressed proteins in the cortex and the striatum indicate that PBDE-99 may alter neurite outgrowth. Finally, we have suggested several improvements in the use of the 2D-DIGE technology. Novel methods for normalizing data were presented, with several advantages compared to existing methods. We have presented a method named DEPPS that makes use of all identified proteins in a dataset to make comprehensive remarks about biological processes affected.

Les anomalies du tube neural (ATN), incluant l'anencéphalie et le spina-bifida, représentent un groupe de malformations congénitales très fréquentes chez l'homme. Ces anomalies sont causées par un défaut partiel ou complet de la fermeture du tube neurale au cours de l'embryogenèse. Les ATN ont une étiologie complexe et multifactorielle impliquant des facteurs environnementaux et génétiques. La voie de signalisation non-canonique du Frizzled (Fz)/Dishevelled (Dvl) contrôle la polarité cellulaire planaire (PCP) et le processus morphogénétique appelé l’extension convergente qui est essentiel pour la gastrulation et la fermeture du tube neural. Très important, des mutations des gènes de cette voie étaient fortement associées aux ATN chez la souris et l’humain. Scribble est un gène de la voie PCP qui cause une sévère ATN chez la souris Circletail. Notre étude vise à analyser le rôle de SCRIBBLE1 dans les ATN humains par des analyses de séquence de son cadre de lecture et ses jonctions exon-introns. Notre étude comporte 396 patients recrutés au Centre Spina Bifida de l’hôpital Gaslini en Gènes, Italie et 83 patients recrutés au Centre Spina Bifida de l’hôpital Sainte Justine. Les patients sont affectés par plusieurs formes d’ATN. Nous avons identifié neuf mutations rares et non synonymes chez 10 patients, p.Asp93Ala (c. 435G>A), p.Gly145Arg (c. 278A>C), p.Gly263Ser (c. 786C>A), p.Gly469Ser (c. 1405G>A), p.Pro649His (c. 1946C>A), p.Gln808His (c. 2424G>T), p.Val1066Met (c. 3196G>A), p.Arg1150Gln (c. 3480G>A) et p.Thr1422Met (c. 4266C>T). Cinque mutations, p.Gly263Ser, p.Pro649His, p.Gln808His, p.Arg1150Gln, p.Thr1422Met, étaient absentes dans les contrôles analysés et prédites d’être pathogéniques in silico. Cette étude montre que des mutations rares dans SCRIB1 pourraient augmenter le risque des ATN dans une fraction des patients. L’identification des gènes prédisposant aux ATN nous aidera à mieux comprendre les mécanismes pathogéniques impliqués dans ces maladies. / Neural tube defects (NTDs), including anencephaly and spina bifida, represent a group of very common birth defects in humans. These anomalies are caused by a partial or complete failure of neural tube closure during embryogenesis. NTDs have a multifactorial etiology involving environmental and genetic factors. The non-canonical signaling pathway Frizzled (Fz) / Dishevelled (Dvl) controls the planar cell polarity (PCP) and the morphogenetic process called convergent extension (CE) which is essential for gastrulation and neural tube closure. Importantly, mutations in genes of this pathway were strongly associated with NTDs in mice and humans. Scribble is a PCP gene that causes a severe NTD mouse Circletail. Scribble binds to another PCP protein, Stbm / Vang, and they cooperate together for the stability of the PCP pathway. Our study aims at investigating the role of SCRIBBLE1 in human NTDs by sequence analyses of its open reading frame and exon-intron junctions. The cohort included in this study consisted of 396 patients recruited at the Spina Bifida Centre of Gaslini Hospital in Genoa, Italy, and 83 patients recruited at the Spina Bifida Center of the Sainte Justine Hospital, Montreal, Canada. Patients were affected by several forms of NTDs. We identified nine non-synonymous and rare mutations in 10 patients: p.Asp93Ala (c. 435G>A), p.Gly145Arg (c. 278A>C), p.Gly263Ser (c. 786C>A), p.Gly469Ser (c. 1405G>A), p.Pro649His (c. 1946C>A), p.Gln808His (c. 2424G>T), p.Val1066Met (c. 3196G>A), p.Arg1150Gln (c. 3480G>A) and p.Thr1422Met (c. 4266C>T). Five of those mutations, p.Gly263Ser, p.Pro649His, p.Gln808His, p.Arg1150Gln, p.Thr1422Met, were absent in all controls analyzed and were predicted to be pathogenic using bioinformatics. Our study demonstrates that rare mutations in SCRIB1 could predispose to NTDs in a fraction of patients. The identification of genes that predispose to ATN will help us better understand the pathogenic mechanisms involved in these diseases.

Neural tube defects (NTDs) are serious birth defects that affect 3,000 pregnancies in the United States annually. All women of childbearing age are recommended to consume 400 micrograms of folic acid daily for the prevention of NTDs. Women aged 18 to 24 years have multiple risk factors for having an NTD-affected pregnancy and should be targeted by efforts to promote folic acid consumption. Survey data capturing folic acid awareness, knowledge, and supplementation behavior of women aged 18 to 24 years who are not contemplating pregnancy were examined to identify the relationship of folic acid awareness and knowledge to daily supplementation with folic acid in an effort to predict the effectiveness of education-only interventions. Results of the study suggested that awareness and knowledge was not consistently related to daily supplementation. An evaluation of qualitative data using the Health Belief Model offers explanations for the findings and recommendations for targeting these at-risk women.

La voie de la polarité planaire cellulaire (PCP), aussi connue sous le nom de la voie non-canonique du Frizzled/Dishevelled, contrôle le processus morphogénétique de l'extension convergente (CE) qui est essentiel pour la gastrulation et la formation du tube neural pendant l'embryogenèse. La signalisation du PCP a été récemment associée avec des anomalies du tube neural (ATN) dans des modèles animaux et chez l'humain. Prickle1 est une protéine centrale de la voie PCP, exprimée dans la ligne primitive et le mésoderme pendant l'embryogenèse de la souris. La perte ou le gain de fonction de Prickle1 mène à des mouvements de CE fautifs chez le poisson zèbre et la grenouille. PRICKLE1 interagit directement avec deux autres membres de la voie PCP, Dishevelled et Strabismus/Vang. Dans notre étude, nous avons investigué le rôle de PRICKLE1 dans l'étiologie des ATN dans une cohorte de 810 patients par le re-séquençage de son cadre de lecture et des jonctions exon-intron. Le potentiel pathogénique des mutations ainsi identifiées a été évalué par des méthodes bioinformatiques, suivi par une validation fonctionnelle in vivo dans un système poisson zèbre. Nous avons identifié dans notre cohorte un total de 9 nouvelles mutations dont sept: p.Ile69Thr, p.Asn81His, p.Thr275Met, p.Arg682Cys et p.Ser739Phe, p.Val550Met et p.Asp771Asn qui affectent des acides aminés conservés. Ces mutations ont été prédites in silico d’affecter la fonction de la protéine et sont absentes dans une large cohorte de contrôles de même origine ethnique. La co-injection de ces variantes avec le gène prickle1a de type sauvage chez l’embryon de poisson zèbre a démontré qu’une mutation, p.Arg682Cys, modifie dans un sens négatif le phénotype du défaut de la CE produit par pk1 de type sauvage. Notre étude démontre que PK1 peut agir comme facteur prédisposant pour les ATN chez l’humain et élargit encore plus nos connaissances sur le rôle des gènes de la PCP dans la pathogenèse de ces malformations. / The planar cell polarity pathway (PCP) or the non-canonical Frizzled/Dishevelled pathway controls the morphogenetic process of convergent extension (CE) that is essential during embryogenesis for gastrulation and neural tube formation. Recently, PCP signalling was associated with neural tube defects (NTD) in humans and animal models. The core PCP protein, Prickle1, is expressed in the primitive streak and mesoderm during mouse embryogenesis. Both gain and loss of function of Prickle1 cause faulty CE movements in zebrafish and the frog. PRICKLE1 physically interacts with two other core PCP members, Dishevelled and Strabismus/Vang. In the present study we investigated the role of PRICKLE1 in the aetiology of NTDs in a large cohort of 810 patients through resequencing of its open reading frame and exon-intron junctions. The pathogenicity of the identified mutations was assessed through bioinformatics methods followed by a functional validation in a zebrafish system, in vivo. We identified in our cohort a total of nine novel mutations, of which seven affected conserved amino acids: p.Ile69Thr, p.Asn81His, p.Thr275Met, p.Arg682Cys, p.Ser739Phe, p.Val550Met and p.Asp771As. These mutations were predicted to affect the function of the protein in silico and were absent in a large cohort of ethnically-matched controls. Co-injection of these variants with the wild type pk1 in zebrafish oocytes revealed that one mutation, p.Arg682Cys, antagonized the CE phenotype induced by the wild-type zebrafish prickle1a in a dominant fashion. Our study demonstrates that PRICKLE1 can represent a predisposing factor for human NTDs and further expands our knowledge on the role that PCP genes in the pathogenesis of these malformations.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2007. / Härtill 5 uppsatser.

No description available.

Objetivo: Verificar se há diferença entre o consumo habitual de folato entre mães de crianças com Síndrome de Down e mães de crianças sem malformações. Métodos: Foi realizado um estudo de caso-controle, com um total de 100 mães das quais 50, incluídas no grupo caso, apresentavam filhos com Síndrome de Down e 50, consideradas grupo controle,tinham filhos sem malformações congênitas. Aplicou-se um questionário de consumo habitual de alimentos contendo questões relativas à classificação sócio-econômica e ao consumo de alimentos-fonte e alimentos fortificados com esta vitamina. Todas participantes assinaram o Termo de Consentimento Livre e Esclarecido. Resultados: Entre as variáveis analisadas, somente a quantidade de ácido fólico consumida habitualmente e a idade no momento do nascimento do filho, diferiram-se significantemente entre os grupos. Mães caso consumiram em média 359,1 μg/dia (dp ± 91,9) de folato, enquanto as mães do grupo controle, 425,5 μg/dia (dp± 104,3), (p=0,001). A idade que tiveram seus filhos foi no grupo caso 27, 5 anos (dp± 4,8) de e no grupo controle de 25,4 (dp ±5,3), (p=0,042). Somente 3,4% das entrevistadas relataram uso de ácido fólico ou polivitamínicos de forma periconcepcional ou em algum momento da gestação. Conclusões: Embora pelo presente estudo tenha havido diferença significativa entre o consumo de folato no grupo caso e no controle é importante que não se descarte possíveis fatores bioquímicos envolvidos e aqui não avaliados. / Objective: Check if exists difference between the usual consumption of folate in mothers of children with Down Syndrome and in mothers of children without congenital abnormalities. Methods: A case-control study was accomplished, with a sample of 100 mothers from which, 50 had children with Down Syndrome and 50, considered group control, children without congenital abnormalities. A questionnaire of quantitative frequency was applied containing questions related to the socioeconomic class and the food-source consumption, and foods fortified with folic acid. All participants signed the Informed Consent Form. Results: Among the variables in analysis, only the daily amount of folic acid consumed and the age that the mothers had their babies were significant different between the two groups. Mothers of children with Down Syndrome consumed 359,1 μg/day (dp ± 91,9) of folate, while the mothers of control group consumed, 425,5 μg/day (dp± 104,3), (p=0,001). The age that they had their babies were in group case 27, 5 years (dp± 4,8) and in the control group, 25,4 (dp ±5,3), (p=0,042). Only 3,4% of the interviewee related use of folic acid or others vitamines before or during the pregnancy. Conclusion: Although in the present study has been a significant difference between the consumption of folate in the case group and in the control, is important not to discard possible biochemical factors involved and here not evaluated.

Objetivo: Verificar se há diferença entre o consumo habitual de folato entre mães de crianças com Síndrome de Down e mães de crianças sem malformações. Métodos: Foi realizado um estudo de caso-controle, com um total de 100 mães das quais 50, incluídas no grupo caso, apresentavam filhos com Síndrome de Down e 50, consideradas grupo controle,tinham filhos sem malformações congênitas. Aplicou-se um questionário de consumo habitual de alimentos contendo questões relativas à classificação sócio-econômica e ao consumo de alimentos-fonte e alimentos fortificados com esta vitamina. Todas participantes assinaram o Termo de Consentimento Livre e Esclarecido. Resultados: Entre as variáveis analisadas, somente a quantidade de ácido fólico consumida habitualmente e a idade no momento do nascimento do filho, diferiram-se significantemente entre os grupos. Mães caso consumiram em média 359,1 μg/dia (dp ± 91,9) de folato, enquanto as mães do grupo controle, 425,5 μg/dia (dp± 104,3), (p=0,001). A idade que tiveram seus filhos foi no grupo caso 27, 5 anos (dp± 4,8) de e no grupo controle de 25,4 (dp ±5,3), (p=0,042). Somente 3,4% das entrevistadas relataram uso de ácido fólico ou polivitamínicos de forma periconcepcional ou em algum momento da gestação. Conclusões: Embora pelo presente estudo tenha havido diferença significativa entre o consumo de folato no grupo caso e no controle é importante que não se descarte possíveis fatores bioquímicos envolvidos e aqui não avaliados. / Objective: Check if exists difference between the usual consumption of folate in mothers of children with Down Syndrome and in mothers of children without congenital abnormalities. Methods: A case-control study was accomplished, with a sample of 100 mothers from which, 50 had children with Down Syndrome and 50, considered group control, children without congenital abnormalities. A questionnaire of quantitative frequency was applied containing questions related to the socioeconomic class and the food-source consumption, and foods fortified with folic acid. All participants signed the Informed Consent Form. Results: Among the variables in analysis, only the daily amount of folic acid consumed and the age that the mothers had their babies were significant different between the two groups. Mothers of children with Down Syndrome consumed 359,1 μg/day (dp ± 91,9) of folate, while the mothers of control group consumed, 425,5 μg/day (dp± 104,3), (p=0,001). The age that they had their babies were in group case 27, 5 years (dp± 4,8) and in the control group, 25,4 (dp ±5,3), (p=0,042). Only 3,4% of the interviewee related use of folic acid or others vitamines before or during the pregnancy. Conclusion: Although in the present study has been a significant difference between the consumption of folate in the case group and in the control, is important not to discard possible biochemical factors involved and here not evaluated.