Objetivos: Investigar possíveis alterações citogenéticas, através da técnica de bandamento de alta resolução, em indivíduos com anomalias craniofaciais associadas ao atraso no desenvolvimento neuropsicomotor e sem diagnóstico clínico-genético definido, com cariótipo (com bandas) prévio normal e estabelecer possível correlação entre o fenótipo dos indivíduos e as regiões cromossômicas alteradas. Local de execução: Laboratório de Citogenética Humana e Serviço de Genética Clínica, HRAC-USP, Bauru-SP. Indivíduos estudados e Resultados: O cariótipo de alta resolução de 16 indivíduos com anomalias craniofaciais associadas ao atraso no desenvolvimento neuropsicomotor pertencentes ao HRAC-USP, Bauru permitiu detectar alterações citogenéticas estruturais em 4 (25%) dos 16 indivíduos. Em 3 indivíduos detectou-se deleções em regiões subteloméricas (cromossomos 4p, 9p e 18q) e, em 1 indivíduo detectou-se adição de segmento cromossômico de origem desconhecida na região telomérica do cromossomo 12p. Conclusões: A frequência alta (25%) de alterações cromossômicas estruturais em regiões cromossômicas terminais (teloméricas e subteloméricas) mostra que a técnica de alta resolução é útil na identificação de alterações nessas regiões, portanto, indivíduos com anomalias craniofaciais e atraso mental, sem diagnóstico genético-clínico definido, cujo cariótipo convencional foi normal, devem ser, submetidos à análise dos cromossomos por meio do cariótipo de alta resolução antes do procedimento de CGHarray. / Objective: To investigate possible cytogenetic abnormalities through high resolution banding technique in individuals with craniofacial anomalies presenting previous normal karyotype, associated to neuropsychological development delay, without clinic-genetic diagnoses, and establish possible correlation between phenotype and possible candidate chromosomal regions. Local: Human Cytogenetic Laboratory and Clinical Genetic Service, HRAC-USP, Bauru, SP. Individuals and Results: High resolution karyotype of 16 individuals with craniofacial anomalies associated to neuropsychological development delay in follow-up at the HRAC-USP, Bauru allowed the detection of structural chromosomal abnormalities in 4 (25%) of them. Three individuals presented deletion in the subtelomeric region (chromosomes 4p, 9p, and 18q), and one individual presented an addition of an unknown chromosomal fragment in the telomeric region of chromosome 12p. Conclusions: The high frequency (25%) of structural chromosomal abnormalities in terminal region (telomeric and subtelomeric) shows that the high resolution technique is useful for identification of structural anomalies in these regions. Therefore, individuals with craniofacial anomalies associated to neuropsychological development delay without a definitive clinic-genetic diagnoses presenting a normal conventional karyotype, should be submitted to chromosomal analysis through high resolution karyotype before CGH-array procedure.

Introdução: A imagem de toda pessoa constitui um direito fundamental resguardado na Constituição Federal, um direito da personalidade, o que possibilita formas específicas de proteger o paciente com anomalia craniofacial, bem como resguardar os direitos dos profissionais responsáveis pela sua reabilitação. Objetivo: O objetivo deste trabalho consiste em verificar o direito constitucional à imagem dos indivíduos com anomalias craniofaciais e sua extensão prática no HRAC/USP. Metodologia: Este estudo prospectivo foi desenvolvido no HRAC/USP após aprovação do Comitê de Ética em Pesquisa em Seres Humanos. Para tanto, foi analisada a legislação que aborda o direito à imagem; as portarias internas da Instituição, com o desiderato de verificar a proteção aos pacientes, bem como os documentos que o HRAC/USP disponibiliza ao paciente na ocasião da inscrição. Resultados e Conclusão: A análise das portarias e demais documentos está apresentada sob a forma descritiva. É possível melhorar o nível de proteção da imagem do paciente com anomalia craniofacial, bem como dos profissionais que lidam com essas imagens, tudo de acordo com o ordenamento jurídico pátrio e os vários Códigos de Ética Profissional. / Introduction: The image of every person is a fundamental right safeguarded by the Federal Constitution, a personality right, which allows specific ways to protect the patient with craniofacial anomalies, as well as protect the rights of the professional who deals with that person daily. Objective: The aim of this study was to check the image constitutional right of individuals with craniofacial anomalies and its practical extension at HRAC/USP. Methods: This prospective study was developed at HRAC/USP after the Ethics Committee in Human Research approval. Therefore legislation that comprises the image right; internal ordinances of the institution, with the desideratum to check the protection of patients as well as the documents that the HRAC/USP provide to the patient at the time of registration were analyzed. Results and Conclusion: The analysis of the ordinances and documents is demonstrated in a descriptive form. The level of the patient with craniofacial anomalies image protection can be improved, as well as of the professionals who deal with these images, all according to the national legal framework and the various Codes of professional Ethics.

<p>The tumor suppressor protein p53, encoded by Tp53 gene, is a transcription factor that regulates cell cycle arrest and apoptosis following cellular stresses that compromise DNA integrity and normal cellular function. Tp53 is mutated in approximately 50% of human cancers, thereby allowing cancer cells to replicate uncontrollably. In cancers in which Tp53 is not mutated, p53 is frequently functionally inactivated through other mechanisms. For example, Mdm2, a proximal negative regulator p53 is often overexpressed in cancers in which p53 is wild-type. Mdm2 is E3 ubiquitin ligase that binds to and targets p53 for proteasomal degradation and as well as inhibits p53 transcriptional activity. Pharmacological disruption of the Mdm2-p53 interaction in cancer cells with wild-type p53 is currently being explored as a strategy to enhance p53-mediated cell death in response to conventional chemotherapeutics. Nutlin-3, an Mdm2 inhibitor, promotes cell death in cultured cells from human medulloblastoma (MB), a common cerebellar pediatric cancer, suggesting that Mdm2 is a promising target to treat this tumor type. Consistent with this idea, studies in a mouse model of MB have shown that loss of Mdm2 limits the development of preneoplastic lesion in the cerebellum. The developing nature of the cerebellum in the youngest of MB patients is a major contributing factor to the side-effects resulting from current MB therapies. Studies in adult rodents suggest that nutlin-3 is non-genotoxic in normal homeostatic tissues; however the effects of nutlin-3 have not been evaluated in developing tissues. To gain insight into the potential side effects of p53 activation on the developing cerebellum, the pharmacological effects of Mdm2 inhibition in Granule Neuron Precursor cells (GNPs) was mimicked genetically using a mouse model in which Mdm2 could be selectively deleted in postnatal GNPs. My studies revealed that deletion of Mdm2 in GNPs led to a reduction in cerebellum size but did not negatively impact gross motor coordination. These results suggest that Mdm2 inhibitors may promote the killing of MB tumor cells of pediatric patients without minimal side effects on normal cerebellum development</p> <p>In addition to cancer, p53 has an important role guarding proliferating cells during development. Activation of p53 has been implicated in the pathology of several human congenital syndromes, and mice lacking Mdm2 die in utero due to p53-mediated apoptosis. These studies highlight the need for p53 function to be tightly regulated as even modest decreases or increases in p53 function can promote cancer or disrupt normal development, respectively. During the course of my studies on Mdm2 inhibition in MB, it was serendipitously discovered that in the absence of a wild-type level of Mdm2, the phenotypic consequences of p53 activation on the developing mouse embryo were strongly influenced by the genetic background. On a 129S6/B6 F1 hybrid genetic background, mice expressing ~30% the wild-type level of Mdm2 were viable, while mice on an inbred C57BL/6 genetic background died at birth and exhibited an array of craniofacial abnormalities including coloboma, exencephaly, and cleft palate. This is the first demonstration of a role for Mdm2 in craniofacial development. The genotype-dependence, further, indicates the presence of additional genes affecting craniofacial dysmorphology. In human pleiotropic malformation syndromes, there is often clinical variability amongst individuals with an identical underlying mutation at the major effect locus. Currently, the modifier genes that influence craniofacial dysmorphology are unknown. The allelic variants encoded by the divergent genetic backgrounds that increase the penetrance and expressivity of craniofacial malformations in the Mdm2 hypomorphic mice identify the gene and protein networks governing craniofacial development. In the future, it will be important to determine the genes that are differentially expressed between mice that express low levels of Mdm2 in C57BL/6 and 129S6/B6 F1 genetic backgrounds. The results from this comparison are predicted to lead to the identification of candidate genes that influence craniofacial development through the modulation of p53 function.</p>

Objetivos: Determinar a precisão das mensurações de dois pontos anatômicos craniométricos pré-estabelecidos, glabela e espinha nasal anterior, para verificar a possibilidade deles serem locais potenciais para a colocação de implantes, visando à retenção de próteses nasais. Métodos: Vinte e seis crânios secos de humanos, divididos em dois grupos iguais dos gêneros masculino e feminino, escaneados por meio de um aparelho tomógrafo espiral, de alta resolução, contínuo, com cortes axiais de 1 mm de espessura, produzidos com 1 mm de intervalo de reconstrução, por 2 segundos de tempo com filtro para tecido ósseo. As imagens obtidas foram armazenadas e transferidas para um workstation, contendo o programa de visualização e-film 1.5.3, para o processamento das imagens dos cortes axiais. A leitura destas mensurações foram realizadas independentemente por dois observadores em duas vezes cada um. Os dados obtidos foram submetidos à análise estatística, com duas variáveis, glabela e espinha nasal anterior, levando-se em consideração um fator de variação: gênero masculino e feminino. Resultados: Os valores médios obtidos para a espinha nasal anterior foram de 12,04 mm no gênero masculino e 11,62 mm no gênero feminino e, para a glabela, de 4,06 mm no gênero masculino e 3,60 no gênero feminino. Conclusões: Os pontos craniométricos avaliados apresentaram valores indicativos da possibilidade de serem utilizados para a colocação de implantes, principalmente, a espinha nasal anterior. Quanto ao gênero, na espinha nasal anterior não houve diferença entre os sexos, e na glabela houve uma pequena diferença estatisticamente insignificante. / Objectives: To determine the precision of the measurements of two preestablished craniometric anatomical points, the glabella and anterior nasal spine, in order to verify their possibility as potential locations for placing implants aimed at the retention of nasal prostheses. Methods: Twenty-six dry human crania (13 male and 13 female) were scanned by means of continuous high-resolution spiral tomography equipment, with axial slices of 1 mm in thickness that were produced with reconstruction intervals of 1mm and a record length of 2 seconds, using a filter for bone tissue. The images obtained were stored and transferred to a workstation containing the e-film 1.5.3 imaging software, to process the axial slice images. The readings of these measurements were done independently by two observers, twice for each measurement. The data obtained were submitted by means of statistical analysis using two variables (glabella and anterior nasal spine) and taking into consideration one variation factor (male or female gender). Results: The mean values obtained for the anterior nasal spine were 12.04 mm for males and 11.62 mm for females. For the glabella they were 4.06 mm for males and 3.60 for females. Conclusions: The craniometric points evaluated presented values that indicated the possibility that they could be utilized for placing implants , particularly the anterior nasal spine. With regard to gender, there was no difference for the anterior nasal spine and a small, statistically non-significant difference for the glabella.

The regenerative tissues such as hair follicles, intestine and teeth have a particular microenvironment known as “stem cell niche” which houses stem cells and act as a signaling center to control stem cell fate. The precise and timely regulation of stem cell renewal and differentiation is essential for tissue formation, growth and homeostasis over the course of a lifetime. However, the molecular underpinning to control this regulation is poorly understood. To address this issue, we use the continuously growing mouse incisor as a model to study the gene regulatory network which controls dental epithelial stem cell (DESC) maintenance, growth and craniofacial morphogenesis. We found FoxO6, a transcription factor mainly expressed in the brain and craniofacial region, control DESC proliferation by regulating Hippo signaling. FoxO6 loss-of-function mice undergo increases in cell proliferation which finally leads to lengthening of the incisors, expansion of the face and skull and enlargement of the mandible and maxilla. We have screened three human FOXO6 single nucleotide polymorphisms which are associated with facial morphology ranging from retrognathism to prognathism. Our study also reveals that Sox2 and Lef-1, two markers for early craniofacial development, are regulated by Pitx2 to control DESC maintenance, differentiation and craniofacial development. Conditional Sox2 deletion in the oral and dental epithelia results in severe craniofacial defects, including ankyloglossia, cleft palate, arrested incisor development and abnormal molar development. The loss of Sox2 in DESCs leads to impaired stem cell proliferation, migration and subsequent dissolution of the tooth germ. On the other hand, conditional overexpression of Lef-1 in oral and dental epithelial region increases DESC proliferation and creates a new labial cervical loop stem cell compartment in dental epithelial stem cell niche, which produces rapidly growing long “tusk-like” incisors. Interestingly, Lef-1 overexpression rescues the tooth arrest defects but not the ankyloglossia or cleft palate in Sox2 conditional deletion mice. Our data also reveal that miRNA and histone remodeler are involved in regulating DESC proliferation and craniofacial morphogenesis. We describe a miR-23a/b:Hmgn2:Pitx2 signaling pathway in regulating dental epithelial cell growth and differentiation. Pitx2 activates expression of amelogenin which is the major protein component for enamel deposition. This activation can be repressed by the chromatin-associated factor Hmgn2. miR-23a and miR-23b directly target Hmgn2, leading to the release of the Hmgn2 inhibition of Pitx2 transcriptional activity and thus enhance Amelogenin production. Phenotypically, ablation of Hmgn2 in mice results in an overgrowth of incisors with increased Amelogenin expression. The findings in this study increase our current understanding of the molecular regulation of dental epithelial stem cell fate. It not only highlights new gene regulatory network that controls dental stem cell maintenance, growth and craniofacial morphogenesis, but also sheds new light on developing novel stem cell therapy or gene therapy for tooth regeneration and dental diseases.

Clefts of the lip and/or palate (CL/P) are one of the most common birth defects in the world occurring about every 1 in 700 live births. Individuals with non-syndromic clefting (NSCL/P) account for about 70% of all cleft cases and exhibit a cleft only whereas syndromic occurrences (SCL/P) include additional cognitive or structural abnormalities. Linkage, genome-wide association, candidate gene, animal model, sequencing and copy number variant (CNV) analyses have been used to study CL/P and have established that it is a heterogeneous, complex disorder. However, the impact of identified sequence variants on protein structure and the contribution of structural genetic variation to CL/P remains poorly understood. In our first analysis we reassessed the phenotype of a 30-year-old individual of SCL/P and noticed phenotypic overlap with Hartsfield syndrome, a rare syndrome resulting from sequence variants in Fibroblast growth factor 1 (FGFR1). We sequenced the coding region of FGFR1 and identified a novel, de novo variant. Due to the fact sequence variants in FGFR1 contribute to multiple syndromes encompassing a wide phenotypic spectrum, we performed an extensive literature search to record every published sequence variant of FGFR1 and mapped it to the protein structure by disease and phenotype. Although no statistically significant protein domain-phenotype correlations were identified, many regions neared significance. This work stresses the need for systematic, comprehensive phenotyping of patients and provides a method for assessing the impact of the location of sequence variants within the 3D structure of the protein. Although rare and common CNVs have been identified in individuals with CL/P, prior to our work no large-scale studies of rare CNVs for the identification of novel clefting genes had been performed. For our second set of analyses, we conducted two such studies, first focusing on a smaller cohort of 140 individuals with NSCL/P from the Philippines to establish our informatic and functional validation pipeline. We used whole-genome tiling arrays to assess rare deletions overlapping genes not previously implicated in clefting, and identified one deletion overlapping Isthmin1 (ISM1) and a deletion just 3’ of the gene in a second affected individual. Functional validation of Ism1 in Xenopus laevis showed strong expression in structures necessary for craniofacial development, and morpholino and CRISPR/Cas9 knockdown of Ism1 resulted in a median cleft lip in some embryos, establishing ISM1 as a novel craniofacial patterning gene. We then expanded our study and assessed genomic CNVs in 1021 individuals with NSCL/P and 81 individuals with SCL/P, finding no differences in CNV number, load or burden between these groups. We also identified 8 putative clefting genes overlapped by deletions in two or more individuals but at a rare (< 1% frequency) in the cohort. Functional validation of these genes using CRISPR/Cas9 in zebrafish and Xenopus tropicalis is currently underway. This work has identified a novel sequence variant leading to the diagnosis of Hartsfield syndrome in an individual with SCL/P, developed an innovative method for assessing the impact of sequence variation on protein structure, improved our understanding of the contribution of CNVs to SCL/P and NSCL/P and identified several putative novel clefting loci which may help explain a portion of the missing heritability of CL/P.

The precise role that genes play in early craniofacial development and postnatal craniofacial growth are essential to understand dento-facial development overall. However, genotype-phenotype correlations between genetic variation of early craniofacial genes and adult craniofacial phenotypes is poorly understood. Thus, this thesis focused on identifying the genetic etiology underlying phenotypic variations present in malocclusion conditions. First, we performed genotype-phenotype association analyses between common variants in 82 craniofacial genes and phenotypic variations extracted from 2D and 3D pre-treatment dental records of individuals with malocclusion. This effort identified that variant rs2189000 upstream of TWIST1 is highly associated with mandibular body length and inclination and cranial base angulations which can lead to malocclusion. Next, via cell based functional assays, we discovered that rs2189000 disrupts a PITX2 binding site and also showed the direct regulation of TWIST1 expression by the PITX2 gene. Finally, we identified abnormal craniofacial phenotypes and malocclusion in Twist1 deleted mice including asymmetric snouts, domed cranial vaults, and changes in size and inclination of the cranial base, palate and mandible resulting in malocclusion and resembling the human phenotypes observed. Also, premature calcification of calvarial sutures and cranial base synchondroses were also observed in the mutant mice indicating a possible biological mechanism for the abnormal phenotypes detected. These results confirm that TWIST1 is an important regulator of postnatal growth and that genetic variation in TWIST1 can result in malocclusion. The continued identification of genetic etiological factors and their role in craniofacial growth will impact treatment and prevention of malocclusion and other craniofacial conditions

Orofacial clefts are a heterogeneous group of craniofacial malformations that affect the lip and/or palate and represent the most common craniofacial birth defect in humans. In 30% of patients the cleft is accompanied by additional physical or cognitive abnormalities. Hundreds of these clefting syndromes have been described, many of which have Mendelian inheritance patterns. The most common of these is Van der Woude syndrome (VWS), caused by mutations in the transcription factor IRF6 (Kondo et al. 2002). The other 70% of patients lack additional features and are considered nonsyndromic. The etiology of nonsyndromic clefts is complex and involves the combined action of multiple genetic variants interacting with environmental factors. A common approach for identifying genetic risk factor for complex disorders such as nonsyndromic cleft lip with or without cleft palate (NSCL/P) is the genome wide association study (GWAS). We pursued a locus on 1p22 shown to be associated with NSCL/P by Beaty et al. (2010). Through a combination of expression studies in a mouse model and mutation screening in NSCL/P patients, we identified ARHGAP29 as a novel gene for NSCL/P and the likely etiologic gene at this locus. We identified eight rare variants in NSCL/P patients absent in controls including a nonsense and a frameshift mutation. These rare variants are reminiscent of previous resequencing studies that reported rare coding mutations in 20 different candidate genes for NSCL/P. We reviewed these variants and compared them with variants found in over 7000 exomes from the 1000 Genomes Project (1kGP) and NHLBI Exome Sequencing Project (ESP) to identify the variants and genes most likely to contain etiologic rare variants. We found good support for a role for rare variants in NSCL/P, particularly for MSX1 and genes of the FGF signaling pathway. We next performed several studies to understand the genetic architecture of syndromic forms of clefting, focusing on VWS and popliteal pterygium syndrome (PPS), which is allelic to VWS. We compiled all of the nearly 300 published IRF6 mutations and compared the distribution of these mutations with IRF6 variants obtained from the 1kGP and ESP exomes. We found that mutations causing VWS were significantly over-represented in the DNA-binding domain and for the most part were absent from control exomes, indicating that they are likely to be truly causative for VWS or PPS. These mutations in VWS and PPS only account for 70% of VWS and 97% of PPS. We next hypothesized that mutations in RIPK4, which causes an autosomal recessive pterygia syndrome, could underlie the remaining VWS and/or PPS cases. We found novel homozygous mutations in RIPK4 in two PPS patients. This result has significant clinical ramifications, as counseling of recurrence risk is very different for PPS patients whose disease is caused by dominant IRF6 mutations compared to recessive RIPK4 mutations. Finally, to understand the variable expressivity of VWS and PPS we performed an association study to identify genetic modifiers. We also looked for genotype-phenotype correlations between the type and location of IRF6 mutations. Although we did not find strong evidence that the candidate genes we selected from GWAS of NSCL/P or other clefting syndromes are modifiers of the VWS or PPS phenotypes, several marginal associations suggest that members of the IRF6 gene regulatory network could act as modifiers. Finally, we found evidence of a larger genotype-phenotype correlation by demonstrating that mutation-negative VWS families have a deficiency of cleft lip phenotypes. Together this work has advanced our understanding of the genetic basis of this diverse set of cleft lip and palate disorders, informing both the biology of craniofacial development and the clinical care of patients affected by these disorders.

A novel injectable hydrogel system for cell delivery in craniofacial bone tissue engineering was developed in this work. The hydrogel employs a dual solidification mechanism by containing units that gel upon temperature increase to physiological temperature and groups that allow for covalent crosslinking. The successful synthesis of macromers for hydrogel fabrication was demonstrated and structure-property relations were established. The hydrophilic-hydrophobic balance of the macromers was found to be an important design criterion towards their resulting thermal gelation properties. When tested with cells in vitro , macromers with different molecular compositions, molecular weights and transition temperatures were all found to be cytocompatible. The introduction of a chemically crosslinkable group in the macromers resulted in hydrogels with improved stability. The effect of the addition of these highly reactive groups on cell viability was evaluated and parameters that enable viable cell encapsulation in the hydrogels were determined. It was shown that there was a dose- and time-dependent effect of the macromers on cell viability. Increased degrees of modification were found to decrease the thermal transition temperature as well as the cytocompatibility of the macromers. Hydrogels were fabricated at physiological temperature upon physical gelation and chemical crosslinking with the addition of a thermal free radical initiator system. The swelling behavior of the hydrogels was characterized and it was found to be controlled by the chemistry of the macromer end group, the concentration of the initiator system used, the fabrication interval as well as the incubation temperature and medium. In order to evaluate the hydrogels as cell carriers, mesenchymal stems cells were encapsulated in the hydrogels over a 21-day period. Cells retained their viability over the duration of the study and exhibited markers of osteogenic differentiation when cultured with appropriate supplements. These findings hold promise for the use of these hydrogel systems for cell encapsulation in tissue engineering applications.

Abstract: Archosauria, the "ruling reptiles," characterized along their stem by relatively large, macrocarnivorous animals, are today represented by two enormously successful but divergent extant clades: Aves, the birds, and Crocodylia, the crocodiles and alligators. This thesis seeks to characterize major transformations in the cranial region of archosaurs, a prominent theme in their evolution.