Project description:Orofacial clefts (OFCs) are the most frequent craniofacial birth defects. An orofacial cleft (OFC) occurs as a result of deviations in palatogenesis. Cell proliferation, differentiation, adhesion, migration and apoptosis are crucial in palatogenesis. We hypothesized that deregulation of these processes in oral keratinocytes contributes to OFC. We performed microarray expression analysis on palatal keratinocytes from OFC and non-OFC individuals. Principal component analysis showed a clear difference in gene expression with 24 and 17% for the first and second component respectively. In OFC cells, 228 genes were differentially expressed (p<0.001). Gene ontology analysis showed enrichment of genes involved in β1 integrin-mediated adhesion and migration, as well as in P-cadherin expression. A scratch assay demonstrated reduced migration of OFC keratinocytes (343.6 ± 29.62 μm) vs. non-OFC keratinocytes (503.4 ± 41.81 μm, p<0.05). Our results indicate that adhesion and migration are deregulated in OFC keratinocytes, which might contribute to OFC pathogenesis.
Project description:Orofacial clefts (OFCs) are the most frequent craniofacial birth defects. An orofacial cleft (OFC) occurs as a result of deviations in palatogenesis. Cell proliferation, differentiation, adhesion, migration and apoptosis are crucial in palatogenesis. We hypothesized that deregulation of these processes in oral keratinocytes contributes to OFC. We performed microarray expression analysis on palatal keratinocytes from OFC and non-OFC individuals. Principal component analysis showed a clear difference in gene expression with 24% and 17% for the first and second component, respectively. In OFC cells, 228 genes were differentially expressed (p < 0.001). Gene ontology analysis showed enrichment of genes involved in ?1 integrin-mediated adhesion and migration, as well as in P-cadherin expression. A scratch assay demonstrated reduced migration of OFC keratinocytes (343.6 ± 29.62 ?m) vs. non-OFC keratinocytes (503.4 ± 41.81 ?m, p < 0.05). Our results indicate that adhesion and migration are deregulated in OFC keratinocytes, which might contribute to OFC pathogenesis.
Project description:Cleft palate is a common congenital anomaly with a live birth prevalence estimated to be 1:2500 live births, that results from failure of growth, elevation, adhesion and/or fusion of the palatal shelves during embryogenesis. Mutations in the gene encoding the transcription factor p63 result in cleft palate in humans and mice. To study the roles of P63 in periderm migration and medial edge epithelia in mice sub-mucous cleft palate, ÎNp63alpha was ectopically expressed in the palatal epithelia using a transgenic approach.
Project description:Background: In humans, cleft palate (CP) accounts for one of the largest number of birth defects with a complex genetic and environmental etiology. TGFM-NM-23 has been established as an important regulator of palatal fusion in mice and it has been shown that TGFM-NM-23-null mice exhibit CP without any other major deformities. However, the genes that regulate cellular decisions and molecular mechanisms maintained by the TGFM-NM-23 pathway throughout palatogenesis are predominantly unexplored. Our objective in this study was to analyze global transcriptome changes within the palate during different gestational ages within TGFM-NM-23 knockout mice to identify TGFM-NM-23-associated genes previously unknown to be associated with the development of cleft palate. We used deep sequencing technology, RNA-Seq, to analyze the transcriptome of TGFM-NM-23 knockout mice at crucial stages of palatogenesis, including palatal growth (E14.5), adhesion (E15.5), and fusion (E16.5). Results: The overall transcriptome analysis of TGFM-NM-23 wildtype mice (C57BL/6) reveals that almost 6000 genes were upregulated during the transition from E14.5 to E15.5 and more than 2000 were downregulated from E15.5 to E16.5. Using bioinformatics tools and databases, we identified the most comprehensive list of CP genes (n = 322) in which mutations cause CP either in humans or mice, and analyzed their expression patterns. The expression motifs of CP genes between TGFM-NM-23+/M-bM-^HM-^R and TGFM-NM-23M-bM-^HM-^R/M-bM-^HM-^R were not significantly different from each other, and the expression of the majority of CP genes remained unchanged from E14.5 to E16.5. Using these patterns, we identified 8 unique genes within TGFM-NM-23M-bM-^HM-^R/M-bM-^HM-^R mice (Chrng Foxc2, H19, Kcnj13, Lhx8, Meox2, Shh, and Six3), which may function as the primary contributors to the development of cleft palate in TGFM-NM-23M-bM-^HM-^R/M-bM-^HM-^R mice. When the significantly altered CP genes were overlaid with TGFM-NM-2 signaling, all of these genes followed the Smad-dependent pathway. Conclusions: Our study represents the first analysis of the palatal transcriptome of the mouse, as well as TGFM-NM-23 knockout mice, using deep sequencing methods. In this study, we characterized the critical regulation of palatal transcripts that may play key regulatory roles through crucial stages of palatal development. We identified potential causative CP genes in a TGFM-NM-23 knockout model, which may lead to a better understanding of the genetic mechanisms of palatogenesis and provide novel potential targets for gene therapy approaches to treat cleft palate. Palatal mRNA profiles of wild type (WT), TGFM-NM-23+/-, and TGFM-NM-23-/- mice at E14.5, E15.5, and E16.5 were generated by deep sequencing, in triplicate, using Illumina HiSeq2000
Project description:Background: In humans, cleft palate (CP) accounts for one of the largest number of birth defects with a complex genetic and environmental etiology. TGFβ3 has been established as an important regulator of palatal fusion in mice and it has been shown that TGFβ3-null mice exhibit CP without any other major deformities. However, the genes that regulate cellular decisions and molecular mechanisms maintained by the TGFβ3 pathway throughout palatogenesis are predominantly unexplored. Our objective in this study was to analyze global transcriptome changes within the palate during different gestational ages within TGFβ3 knockout mice to identify TGFβ3-associated genes previously unknown to be associated with the development of cleft palate. We used deep sequencing technology, RNA-Seq, to analyze the transcriptome of TGFβ3 knockout mice at crucial stages of palatogenesis, including palatal growth (E14.5), adhesion (E15.5), and fusion (E16.5). Results: The overall transcriptome analysis of TGFβ3 wildtype mice (C57BL/6) reveals that almost 6000 genes were upregulated during the transition from E14.5 to E15.5 and more than 2000 were downregulated from E15.5 to E16.5. Using bioinformatics tools and databases, we identified the most comprehensive list of CP genes (n = 322) in which mutations cause CP either in humans or mice, and analyzed their expression patterns. The expression motifs of CP genes between TGFβ3+/− and TGFβ3−/− were not significantly different from each other, and the expression of the majority of CP genes remained unchanged from E14.5 to E16.5. Using these patterns, we identified 8 unique genes within TGFβ3−/− mice (Chrng Foxc2, H19, Kcnj13, Lhx8, Meox2, Shh, and Six3), which may function as the primary contributors to the development of cleft palate in TGFβ3−/− mice. When the significantly altered CP genes were overlaid with TGFβ signaling, all of these genes followed the Smad-dependent pathway. Conclusions: Our study represents the first analysis of the palatal transcriptome of the mouse, as well as TGFβ3 knockout mice, using deep sequencing methods. In this study, we characterized the critical regulation of palatal transcripts that may play key regulatory roles through crucial stages of palatal development. We identified potential causative CP genes in a TGFβ3 knockout model, which may lead to a better understanding of the genetic mechanisms of palatogenesis and provide novel potential targets for gene therapy approaches to treat cleft palate.
Project description:Orofacial clefts of the lip and palate are widely recognized to result from complex gene–environment interactions, but inadequate understanding of environmental risk factors has stymied development of prevention strategies. We interrogated the role of DNA methylation, an environmentally malleable epigenetic mechanism, in orofacial development. Expression of the key DNA methyltransferase enzyme DNMT1 was detected throughout palate morphogenesis in the epithelium and underlying cranial neural crest cell (cNCC) mesenchyme, a highly proliferative multipotent stem cell population that forms orofacial connective tissue. Genetic and pharmacologic manipulations of DNMT activity were then applied to define the tissue- and timing-dependent requirement of DNA methylation in orofacial development. cNCC-specific Dnmt1 inactivation targeting initial palate outgrowth resulted in OFCs, while later targeting during palatal shelf elevation and elongation did not. Conditional Dnmt1 deletion reduced cNCC proliferation and subsequent differentiation trajectory, resulting in attenuated outgrowth of the palatal shelves and altered development of cNCC-derived skeletal elements. Finally, we found that the cellular mechanisms of cleft pathogenesis observed in vivo can be recapitulated by pharmacologically reducing DNA methylation in multipotent cNCCs cultured in vitro. These findings demonstrate that DNA methylation is a crucial epigenetic regulator of cNCC biology, define a critical period of development in which its disruption directly causes OFCs, and provide opportunities to identify environmental influences that contribute to OFC risk.
Project description:Deletion of Tbx1, a member of the T-box transcription factor gene family, results in abnormal epithelial fusion between the palatal shelves and the mandible, which induces cleft palate by inhibiting elevation of the palatal shelves. We used microarrays to determine the downstream genes of Tbx1 during palatogenesis and identified distinct classes of dysregulated genes.
Project description:The overall goal of this project is to investigate the role of TGF-beta signaling in palate development in order to discover candidate therapeutics for preventing and treating congenital birth defects. Here, we conducted gene expression profiling of embryonic palatal tissue from wild type mice as well as those with a neural crest specific conditional inactivation of the Tgfbr2 gene. The latter mice provide a model of cleft palate formation. To investigate the mechanism of cleft palate resulting from mutations in TGFBR2, we analyzed neural crest specific conditional inactivation of Tgfbr2 in mice (Tgfbr2fl/fl;Wnt1-Cre). We performed microarray analyses using the palatal tissue of Tgfbr2fl/fl;Wnt1-Cre mice at embryonic day E13.5 (prior to palatal fusion, n=6 per genotype) and E14.5 (during palatal fusion, n=5 per genotype) to examine the genes regulated by Tgf-beta during palate formation.
Project description:Mutations in the transcription factor p63 underlie of a series of human malformation syndromes which are defined by a combination of epidermal, limb and craniofacial abnormalities including cleft lip and palate. Transcription profiling was performed to determine the role of p63 in vivo mouse palatal shelves. Microarray analysis was done of palatal shelves dissected from E14.0 wild-type versus p63-null mouse embryos.