TGFbeta isoforms and decorin gene expression are modified in fibroblasts obtained from non-syndromic cleft lip and palate subjects

The important role of MDM2, RPL5, and TP53 in mycophenolic acid-induced cleft lip and palate

Mycophenolate embryopathy (MPE) is a mycophenolic acid (MPA)-induced congenital malformation with distinctive symptoms. Cleft lip/palate (CLP) is one of the most common symptoms of MPE. The aim of this study was to screen and verify hub genes involved in MPA-induced CLP and to explore the potential molecular mechanisms underlying MPE.Overlapping genes related to MPA and CLP were obtained from the GeneCards database. These genes were further analyzed via bioinformatics. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis results were visualized with the Cytoscape ClueGO plug-in. Gene protein-protein interaction (PPI) networks were constructed based on data obtained from the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database.Overall, 58 genes related to MPA and CLP were identified. The genes most relevant to MPA-induced CLP included ABCB1, COL1A1, Rac1, TGFβ1, EDN1, and TP53, as well as the TP53-associated genes MDM2 and RPL5. GO analysis demonstrated gene enrichment regarding such terms as ear, mesenchymal, striated muscle, and ureteric development. KEGG analysis demonstrated gene enrichment in such pathways as the HIF-1 signaling pathway, glycosylphosphatidylinositol-anchor biosynthesis, the TNF signaling pathway, and hematopoietic stem cell development.Bioinformatic analysis was performed on the genes currently known to be associated with MPA-induced CLP pathogenesis. MPA-induced CLP is mediated by multiple ribosome stress related genes and pathways. MDM2, RPL5 and TP53 could be the main contributor in this pathogenesis, along with several other genes. ABCB1 polymorphism could be related to the probability of MPA-induced CLP.

Deregulated Adhesion Program in Palatal Keratinocytes of Orofacial Cleft Patients

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.

TGF-β Signaling and the Epithelial-Mesenchymal Transition during Palatal Fusion

Signaling by transforming growth factor (TGF)-β plays an important role in development, including in palatogenesis. The dynamic morphological process of palatal fusion occurs to achieve separation of the nasal and oral cavities. Critically and specifically important in palatal fusion are the medial edge epithelial (MEE) cells, which are initially present at the palatal midline seam and over the course of the palate fusion process are lost from the seam, due to cell migration, epithelial-mesenchymal transition (EMT), and/or programed cell death. In order to define the role of TGF-β signaling during this process, several approaches have been utilized, including a small interfering RNA (siRNA) strategy targeting TGF-β receptors in an organ culture context, the use of genetically engineered mice, such as Wnt1-cre/R26R double transgenic mice, and a cell fate tracing through utilization of cell lineage markers. These approaches have permitted investigators to distinguish some specific traits of well-defined cell populations throughout the palatogenic events. In this paper, we summarize the current understanding on the role of TGF-β signaling, and specifically its association with MEE cell fate during palatal fusion. TGF-β is highly regulated both temporally and spatially, with TGF-β3 and Smad2 being the preferentially expressed signaling molecules in the critical cells of the fusion processes. Interestingly, the accessory receptor, TGF-β type 3 receptor, is also critical for palatal fusion, with evidence for its significance provided by Cre-lox systems and siRNA approaches. This suggests the high demand of ligand for this fine-tuned signaling process. We discuss the new insights in the fate of MEE cells in the midline epithelial seam (MES) during the palate fusion process, with a particular focus on the role of TGF-β signaling.

Ultrastructural analysis of collagen fibril diameter distribution in cleft lip

OBJECTIVE

A preliminary study to determine collagen fibril diameter (CF-ED) distribution on medial and lateral sides of cleft lip (CL).

MATERIAL AND METHODS

Tissue samples from medial and lateral sides of CL were fixed in 2.5% glutaraldehyde and 1% osmium tetroxide and embedded in Araldite CY212 resin for transmission electron microscopy. The analysis of CF-ED was performed using the ImageJ program. To characterize the packaging of collagen fibrils (CFs) in the two tissues, we estimated the collagen number density (CF-ND) and fibril-area-fraction (FAF). Differences in measurements across the two sides were calculated using Wilcoxon signed-rank test.

RESULTS

The CF-ED was statistically significantly (p < 0.001) smaller on the medial side (45.69 ± 7.89 nm) than on the lateral side (54.18 ± 7.62 nm). The medial side had a higher CF-ND and a higher percentage of FAF than the lateral side.

CONCLUSION

Our finding of a smaller CF-ED and higher CF-ND and FAF for the medial side suggests possible differences in size and distribution of CFs between medial and lateral sides of CL. This finding provides knowledge toward underlying tissue biomechanics that may help reconstruction of perioral tissue scaffolds, ultimately resulting in better treatment of patients with oral clefts.

Cleft palate only: current concepts

Cleft palate only (CPO) is one of the most common congenital malformations worldwide. The etiopathogenesis of CPO is not completely understood. Environmental factors, such as smoking, alcohol consumption, intake of drugs during pregnancy, advanced paternal age, have been demonstrated to be a risk of CPO, but conflicting results have also been published. Insufficient intake of folic acid during the pregnancy has been suggested to increase the risk for CPO. The demonstrated risk for siblings and the higher risk for monozygotic twins suggest a genetic etiopathogenesis for CPO. In some cases of CPO a prevalent mode of inheritance has been reported, but oligogenic models with reduced penetrance, and the risk related to environmental factors have also been proved. One of the first manifestations associated with CPO is difficulty with feeding. Aerophagia is a problem in these infants with CPO and requires more frequent burping and slower feeding. The inability to generate intraoral breath pressure due to nasal air emission in CPO children frequently manifests as articulation difficulties, particularly consonant weakness, and unintelligible speech. Hearing disorders are prevalent among individuals with CPO, as a result of chronic otitis media with effusion due to eustachian tube dysfunction. A multidisciplinary team is essential to manage the many aspects of CPO. In treating CPO, the reconstructive surgeon works in cooperation with otolaryngologists, dentists and orthodontists, speech pathologists, audiologists, geneticists, psychiatrists, maxillofacial surgeons, social workers, and prosthodontists. CPO can be considered a genetically complex disease, but new knowledge and new therapeutic approaches have greatly improved the quality of life of these children. Prenatal diagnosis is an important step in the treatment of this disease.

New insights in orofacial cleft: epidemiological and genetic studies on italian samples

Cleft of the lip and/or palate (CL±P) is the most common congenital craniofacial anomaly affecting around 1 in 700 live births worldwide. Clefts of the human face can be classified anatomically as cleft lip only (CL), cleft palate only (CP), cleft lip and palate (CLP) or a combined group of cleft lip with or without cleft palate (CL±P), based on differences in embryologic development. CL±P has a genetic base and several linkage and association analyses have been performed in order to obtain important information about the role of candidate genes in its onset; not less important are gene-environment interactions that play an increasing role in its aetiology. In CL±P, several loci have been seen associated with the malformation, and, in some cases, a specific gene mapping in a locus has also been identified as susceptibility factor. In CP, one gene has been found, but many more are probably involved. In this short review the genetic studies carried out on CL±P, and the interaction with environmental factors (alcohol, smoking, drugs) are discussed.

Correlation of proliferation, TGF-β3 promoter methylation, and Smad signaling in MEPM cells during the development of ATRA-induced cleft palate

Mesenchymal cell proliferation is one of the processes in shelf outgrowth. Both all-trans retinoic acid (atRA) and transforming growth factor-β3 (TGF-β3) play an important role in mouse embryonic palate mesenchymal (MEPM) cell proliferation. The cellular effects of TGF-β are mediated by Smad-dependent or Smad-independent pathways. In the present study, we demonstrate that atRA promotes TGF-β3 promoter demethylation and protein expression, but can cause depression of mesenchymal cell proliferation, especially at embryonic day 14 (E14). Moreover, the inhibition of MEPM cell proliferation by atRA results in the downregulation of Smad signaling mediated by transforming growth interacting factor (TGIF). We speculate that the effects of atRA on MEPM cell proliferation may be mediated by Smad pathways, which are regulated by TGIF but are not related to TGF-β3 expression. Finally, the cellular effects of TGF-β3 on MEPM cell proliferation may be mediated by Smad-independent pathways.

New insights in collagen turnover in orofacial cleft patients

OBJECTIVE

We aimed to characterize the fibroblast phenotype of patients by analyzing gene and protein expression of cleft lip and/or cleft palate fibroblasts in relation to collagen turnover and extracellular matrix remodeling.

PATIENTS

Human palatal fibroblasts were obtained from three healthy subjects without cleft lip and/or cleft palate and from three subjects with nonsyndromic cleft lip and/or cleft palate. Collagen turnover-related gene and protein expression were analyzed by real-time polymerase chain reaction, Western and dot blots, and sodium dodecyl sulfate zymography.

RESULTS

Cleft lip and/or cleft palate fibroblasts, compared with controls, displayed a down-regulation of collagens type I and III messenger RNA (p < .0001 and p < .001, respectively) but an opposite tendency to increase protein levels. Cleft lip and/or cleft palate cells had higher lysyl hydroxylase-2b messenger RNA levels expressed in relation to collagen type I messenger RNA, down-regulated matrix metalloproteinase-1, tissue inhibitor of matrix metalloproteinase-1, and Secreted Protein Acidic and Rich in Cysteine messenger RNA (p < .0001 and p < .01, respectively). Pro-matrix metalloproteinase-1 tended to decrease, and pro-matrix metalloproteinase-2 and -9 were down-regulated (p < .01, p < .05, respectively), as was Secreted Protein Acidic and Rich in Cysteine protein expression (p < .05).

CONCLUSIONS

Our results suggest that the cleft lip and/or cleft palate fibroblast phenotype is characterized by a tendency toward interstitial collagen deposition due to posttranslational modifications, such as decreased collagen degradation by matrix metalloproteinases and increased collagen cross-links. These findings may contribute to the knowledge of the cleft lip and/or cleft palate fibroblast phenotype and may be useful to the surgeon when considering the potential wound contraction and subsequent undesired scarring in cleft lip and/or cleft palate ocurring after the surgical closure of a cleft palate.

Implications of TGFβ on Transcriptome and Cellular Biofunctions of Palatal Mesenchyme

Development of the palate comprises sequential stages of growth, elevation, and fusion of the palatal shelves. The mesenchymal component of palates plays a major role in early phases of palatogenesis, such as growth and elevation. Failure in these steps may result in cleft palate, the second most common birth defect in the world. These early stages of palatogenesis require precise and chronological orchestration of key physiological processes, such as growth, proliferation, differentiation, migration, and apoptosis. There is compelling evidence for the vital role of TGFβ-mediated regulation of palate development. We hypothesized that the isoforms of TGFβ regulate different cellular biofunctions of the palatal mesenchyme to various extents. Human embryonic palatal mesenchyme (HEPM) cells were treated with TGFβ1, β2, and β3 for microarray-based gene expression studies in order to identify the roles of TGFβ in the transcriptome of the palatal mesenchyme. Following normalization and modeling of 28,869 human genes, 566 transcripts were detected as differentially expressed in TGFβ-treated HEPM cells. Out of these altered transcripts, 234 of them were clustered in cellular biofunctions, including growth and proliferation, development, morphology, movement, cell cycle, and apoptosis. Biological interpretation and network analysis of the genes active in cellular biofunctions were performed using IPA. Among the differentially expressed genes, 11 of them are known to be crucial for palatogenesis (EDN1, INHBA, LHX8, PDGFC, PIGA, RUNX1, SNAI1, SMAD3, TGFβ1, TGFβ2, and TGFβR1). These genes were used for a merged interaction network with cellular behaviors. Overall, we have determined that more than 2% of human transcripts were differentially expressed in response to TGFβ treatment in HEPM cells. Our results suggest that both TGFβ1 and TGFβ2 orchestrate major cellular biofunctions within the palatal mesenchyme in vitro by regulating expression of 234 genes.

Contribution of MSX1 variants to the risk of non-syndromic cleft lip and palate in a Malay population

Oral clefts are clinically and genetically heterogeneous disorders that are influenced by both genetic and environmental factors. The present family-based association study investigated the role of the MSX1 and TGFB3 genes in the etiology of non-syndromic oral cleft in a Malay population. No transmission distortion was found in the transmission disequilibrium analysis for either MSX1-CA or TGFB3-CA intragenic markers, whereas TGFB3-CA exhibited a trend to excess maternal transmission. In sequencing the MSX1 coding regions in 124 patients with oral cleft, five variants were found, including three known variants (A34G, G110G and P147Q) and two novel variants (M37L and G267A). The P147Q and M37L variants were not observed in 200 control chromosomes, whereas G267A was found in one control sample, indicating a very rare polymorphic variant. Furthermore, the G110G variant displayed a significant association between patients with non-syndromic cleft lip, with or without cleft palate, and normal controls (P=0.001, odds ratio=2.241, 95% confidence interval, 1.357-3.700). Therefore, these genetic variants may contribute, along with other genetic and environmental factors, to this condition.

Diazepam effects on non-syndromic cleft lip with or without palate: epidemiological studies, clinical findings, genes and extracellular matrix

IMPORTANCE OF THE FIELD

This review analyses international studies investigating the combined genetic and environmental causes of cleft lip with or without cleft palate (CL/P) and describes successes and limitations in identifying underlying genetic and environmental factors. CL/P, the most common congenital facial malformation, is a major public health burden in terms of medical costs and emotional stress to patients and families. Because genetic and environmental factors determine risk of occurrence, CL/P has a complex, multifactor aetiology.

AREAS COVERED IN THIS REVIEW

English language reports from 1980 to 2010 were searched for in Medline, PubMed, Science Citation Index, textbooks and review articles on drugs and pregnancy. Key words were diazepam or benzodiazepine(s) combined with cleft lip, cleft palate, oral malformations, prenatal exposure, GABA, gene expression and extracellular matrix.

WHAT THE READER WILL GAIN

This review presents an updated assessment of the mutagenic and genotoxic effects of diazepam (DZ), one of the most commonly used benzodiazepines, on CL/P occurrence.

TAKE HOME MESSAGE

Data are divergent; more studies are needed for an in-depth picture of the effects of DZ during gestation on the child's development, particularly on orofacial clefts.

Human cleft lip and palate fibroblasts and normal nicotine-treated fibroblasts show altered in vitro expressions of genes related to molecular signaling pathways and extracellular matrix metabolism

Nonsyndromic cleft lip with or without cleft palate (CLP) is a frequent craniofacial malformation caused by both genetic and environmental factors. Maternal smoking during pregnancy is a known risk factor, due to the teratogenic role of nicotine. To assess and compare the impact of CLP and nicotine, we studied the quantitative expression of genes involved in signaling pathways and extracellular matrix (ECM) metabolism in human normal nicotine-treated (NicN) and CLP fibroblasts compared to normal control (CTRL) cells. Palatal fibroblast cultures from seven CLP children and seven age-matched CTRL subjects were established and subconfluent cells incubated for 24 h without (CTRL and CLP fibroblasts) or with (NicN fibroblasts) 0.6 mM nicotine. Gene expressions were analyzed by real-time quantitative PCR. For the first time, a regulated cholinergic signaling in our human fibroblasts in vitro was demonstrated. Members of TGF-beta, retinoic acid (RA), and GABA-ergic signaling systems were also differently regulated. Among the ECM genes, fibronectin, syndecan, integrin alpha2, and MMP13 genes were concordantly modulated, while integrin beta5, and decorin genes were discordantly modulated. Interestingly, nicotine treatment regulated gene expressions of CD44 and CLPTM1, two candidate genes for CLP. Our findings show a positive association between nicotine treatment and CLP phenotype. Results suggest that nicotine deranges normal palate development, which might contribute to the development of a CLP malformative phenotype, through the impairment of some important signaling systems and ECM composition.

Patterns of some extracellular matrix gene expression are similar in cells from cleft lip-palate patients and in human palatal fibroblasts exposed to diazepam in culture

Prenatal exposure to diazepam, a prototype sedative drug that belongs to Benzodiazepines, can lead to orofacial clefting in human newborns. By using real-time PCR, in the present study we investigated whether diazepam elicits gene expression alterations in extracellular matrix (ECM) components, growth factors and gamma-aminobutyric acid receptor (GABRB3), implicated in the coordinate regulation of palate development. Palate fibroblasts were treated with diazepam (Dz-N fibroblasts) and compared to cleft lip-palate (CLP) fibroblasts obtained from patients with no known exposure to diazepam or other teratogens. Untreated fibroblasts from non-CLP patients were used as control. The results showed significant convergences in gene expression pattern of collagens, fibromodulin, vitronectin, tenascin C, integrins and metalloprotease MMP13 between Dz-N and CLP fibroblasts. Among the growth factors, constitutive Fibroblast Growth Factor 2 (FGF2) was greatly enhanced in Dz-N and CLP fibroblasts and associated with a higher reduction of FGF receptor. Transforming Growth Factor beta 3 (TGFbeta(3)) resulted up-regulated in CLP fibroblasts and decreased in Dz-N fibroblasts. We found phenotypic differences exhibited by Dz-N and CLP fibroblasts in GABRB3 gene regulation, so further studies are necessary to determine whether GABAergic system could be involved in the development of diazepam mediated CLP phenotype. Taken together the results elucidate the molecular mechanisms underlying possible toxicology effects induced by diazepam. Counselling of women on the safety of diazepam exposure is clinically important, also for the forensic consequences.

Cleft Palate Cells Can Regenerate a Palatal Mucosa in vitro

Cleft palate repair leaves full-thickness mucosal defects on the palate. Healing might be improved by implantation of a mucosal substitute. However, the genetic and phenotypic deviations of cleft palate cells may hamper tissue engineering. The aim of this study was to construct mucosal substitutes from cleft palate cells, and to compare these with substitutes from normal palatal cells, and with native palatal mucosa. Biopsies from the palatal mucosa of eight children with cleft palate and eight age-matched control individuals were taken. Three biopsies of both groups were processed for (immuno)histochemistry; 5 were used to culture mucosal substitutes. Histology showed that the substitutes from cleft-palate and non-cleft-palate cells were comparable, but the number of cell layers was less than in native palatal mucosa. All epithelial layers in native palatal mucosa and mucosal substitutes expressed the cytokeratins 5, 10, and 16, and the proliferation marker Ki67. Heparan sulphate and decorin were present in the basal membrane and the underlying connective tissue, respectively. We conclude that mucosal cells from children with cleft palate can regenerate an oral mucosa in vitro.

TGF alpha has low protein expression in nonsyndromic clefts

Genetic studies have demonstrated that nonsyndromic cleft is composed of two separate entities: the cleft palate only and cleft of the lip, alveolus with or without cleft palate; both have a heterogeneous genetic background and environmental factors contribute to the onset of these malformations. The role of transforming growth factor alpha (TGF-A) was considered possible, but conflicting results have been reported. To detect if TGF-A is involved in the onset of cleft diseases, a series of patients with nonsyndromic clefts and control subjects were analyzed with regard to protein expression. Forty-three patients with nonsyndromic clefts and 21 unaffected subjects were enrolled in this study. Paraffin-embedded specimens were matched with TGF-A antibody and then scanned with a computerized image analyzer. TGF-A was scored as absent, moderately (from 10% to 30%), and highly expressed in epithelium, gland, and muscle. Data were statistically analyzed with a Kruskal-Wallis test. Comparison between control subjects and patients with clefts showed that only gland and epithelium reached a significant P value. A subsequent comparison between cleft of the lip, alveolus with or without cleft palate and cleft palate only groups demonstrated a statistically significant difference only for gland. TGF-A was decreasingly expressed in unaffected, cleft of the lip, alveolus with or without cleft palate, and patient with cleft palate only and thus further strength has been given to its role in the onset of the disease.

Downregulated gene expression in human palate fibroblasts after cyclosporin A treatment

BACKGROUND

Cyclosporin A is a powerful immunosuppressive drug with considerable impact on transplants and is able to modify extracellular matrix (ECM) composition. It has recently been demonstrated that cyclosporin A stimulates the production of the cytokine family. Cytokines such as interleukin, transforming growth factor beta(1), and bone morphogenetic protein induce the deposition of glycosaminoglycans (GAGs), proteoglycans, and collagen fibers in the connective ECM. ECM composition is very important for normal tissue development and function. In this work, we examine the effects caused by cyclosporin A on cultures of normal human palate fibroblasts in order to evaluate interleukin, transforming growth factor beta II, and bone morphogenetic protein II membrane receptor induction and extracellular GAG changes such as hyaluronic acid, heparin sulfate, and chondroitin sulfate.

METHODS

Palate fibroblasts were maintained for 24 h in serum-free 199 medium containing 5 microg/mL (3)H glucosamine hydrochloride. After this time, TGF II and BMP II receptors were determined by microarray analysis and GAG classes by the biochemical method.

RESULTS

The results show that TGFbeta(1) II and BMP II membrane receptors are significantly inhibited in cyclosporin A-treated cultures as compared to controls, whereas IL-1R2 membrane receptors are stimulated. The behavior of total intra- and extracellular GAGs is significantly increased in cyclosporin A-treated cultures, whereas the ratio between non-sulfated/sulfated GAGs decreases (p <or=0.01) vis-à-vis controls.

CONCLUSIONS

Because they form a highly complicated macromolecular network in the ECM, which provides an indication of cell function and gene expression and modulates growth factor activities, GAG changes are related to modification of ECM functions. Our data show that cyclosporin A causes biochemical changes to ECM through alterations in cytokines and respective membrane receptor linkages.

Retinoic acid, GABA-ergic, and TGF-beta signaling systems are involved in human cleft palate fibroblast phenotype

During embryogenesis, a complex interplay between extracellular matrix (ECM) molecules, regulatory molecules, and growth factors mediates morphogenetic processes involved in palatogenesis. Transforming growth factor-beta (TGF-beta), retinoic acid (RA), and gamma-aminobutyric acid (GABA)ergic signaling systems are also potentially involved. Using [3H]glucosamine and [35S]methionine incorporation, anion exchange chromatography, semiquantitative radioactive RT-PCR, and a TGF-beta binding assay, we aimed to verify the presence of phenotypic differences between primary cultures of secondary palate (SP) fibroblasts from 2-year-old subjects with familial nonsyndromic cleft lip and/or palate (CLP-SP fibroblasts) and age-matched normal SP (N-SP) fibroblasts. The effects of RA--which, at pharmacologic doses, induces cleft palate in newborns of many species--were also studied. We found an altered ECM production in CLP-SP fibroblasts that synthesized and secreted more glycosaminoglycans (GAGs) and fibronectin (FN) compared with N-SP cells. In CLP-SP cells, TGF-beta3 mRNA expression and TGF-beta receptor number were higher and RA receptor-alpha (RARA) gene expression was increased. Moreover, we demonstrated for the first time that GABA receptor (GABRB3) mRNA expression was upregulated in human CLP-SP fibroblasts. In N-SP and CLP-SP fibroblasts, RA decreased GAG and FN secretion and increased TGF-beta3 mRNA expression but reduced the number of TGF-beta receptors. TGF-beta receptor type I mRNA expression was decreased, TGF-beta receptor type II was increased, and TGF-beta receptor type III was not affected. RA treatment increased RARA gene expression in both cell populations but upregulated GABRB3 mRNA expression only in N-SP cells. These results show that CLP-SP fibroblasts compared with N-SP fibroblasts exhibit an abnormal phenotype in vitro and respond differently to RA treatment, and suggest that altered crosstalk between RA, GABAergic, and TGF-beta signaling systems could be involved in human cleft palate fibroblast phenotype.

Retinoic acid, GABA-ergic, and TGF-beta signaling systems are involved in human cleft palate fibroblast phenotype

During embryogenesis, a complex interplay between extracellular matrix (ECM) molecules, regulatory molecules, and growth factors mediates morphogenetic processes involved in palatogenesis. Transforming growth factor-beta (TGF-beta), retinoic acid (RA), and gamma-aminobutyric acid (GABA)ergic signaling systems are also potentially involved. Using [3H]glucosamine and [35S]methionine incorporation, anion exchange chromatography, semiquantitative radioactive RT-PCR, and a TGF-beta binding assay, we aimed to verify the presence of phenotypic differences between primary cultures of secondary palate (SP) fibroblasts from 2-year-old subjects with familial nonsyndromic cleft lip and/or palate (CLP-SP fibroblasts) and age-matched normal SP (N-SP) fibroblasts. The effects of RA--which, at pharmacologic doses, induces cleft palate in newborns of many species--were also studied. We found an altered ECM production in CLP-SP fibroblasts that synthesized and secreted more glycosaminoglycans (GAGs) and fibronectin (FN) compared with N-SP cells. In CLP-SP cells, TGF-beta3 mRNA expression and TGF-beta receptor number were higher and RA receptor-alpha (RARA) gene expression was increased. Moreover, we demonstrated for the first time that GABA receptor (GABRB3) mRNA expression was upregulated in human CLP-SP fibroblasts. In N-SP and CLP-SP fibroblasts, RA decreased GAG and FN secretion and increased TGF-beta3 mRNA expression but reduced the number of TGF-beta receptors. TGF-beta receptor type I mRNA expression was decreased, TGF-beta receptor type II was increased, and TGF-beta receptor type III was not affected. RA treatment increased RARA gene expression in both cell populations but upregulated GABRB3 mRNA expression only in N-SP cells. These results show that CLP-SP fibroblasts compared with N-SP fibroblasts exhibit an abnormal phenotype in vitro and respond differently to RA treatment, and suggest that altered crosstalk between RA, GABAergic, and TGF-beta signaling systems could be involved in human cleft palate fibroblast phenotype.

TGFbeta3 expression in non-syndromic orofacial clefts

BACKGROUND

Genetic studies have demonstrated that non-syndromic cleft is composed of two separate entities - cleft palate only (CPO) and cleft of lip, alveolus with or without cleft palate (CL+/-P) -, both have a heterogeneous genetic background and environmental factors contribute to the onset of these malformations. Previous studies have shown that TGFbeta3 could be involved in these diseases, but no conclusive results have been reached.

PURPOSE

In order to detect if TGFbeta3 has a role in cleft diseases, a series of non-syndromic cleft patients and controls are analyzed for TGFbeta3 protein expression.

MATERIAL AND METHODS

Forty-three non-syndromic cleft patients and 21 unaffected subjects were involved in this study. Paraffin-embedded specimens were matched with the TGFbeta3 antibody and then scanned with a computerized image analyzer. TGFbeta3 was found to be absent (less than 10%), moderate (from 10% to 30%) and highly expressed (higher than 30%) in epithelium (EP), minor palatal salivary gland (GL) and fibres of elevator palati muscle (MU). Data was statistically analyzed with a Kruskal-Wallis test.

RESULTS

Only GL and EP have a statistically significant lower expression in non-syndromic cleft compared to unaffected subjects. A subsequent comparison between CL+/-P and CPO groups demonstrates a statistically significant difference only for GL, with a lower expression in GL of CPO patients.

CONCLUSIONS

TGFbeta3 is decreasingly expressed in GL of unaffected CL+/-P and CPO patients and thus further strength is given to a pathogenetic role of TGFbeta3 in the onset of clefts.

Plasminogen activator inhibitor-I–related regulation of procollagen I (α1 and α2) by antitransforming growth factor-β1 treatment during radiation-impaired wound healing

PURPOSE

Plasminogen activator inhibitor (PAI)-1 mediates transforming growth factor-beta1 (TGF-beta1)-related signaling by stimulating collagen Type I synthesis in radiation-impaired wound healing. The regulation of alpha(I)-procollagen is contradictory in fibroblasts of different fibrotic lesions. It is not known whether anti-TGF-beta1 treatment specifically inhibits alpha(I)-procollagen synthesis. We used an experimental wound healing study to address anti-TGF-beta1-associated influence on alpha(I)-procollagen synthesis.

METHODS AND MATERIALS

A free flap was transplanted into the preirradiated (40 Gy) or nonirradiated neck region of Wistar rats: Group 1 (n = 8) surgery alone; Group 2 (n = 14) irradiation and surgery; Group 3 (n = 8) irradiation and surgery and anti-TGF-beta1 treatment. On the 14th postoperative day, skin samples were processed for fibroblast culture, in situ hybridization for TGF-beta1, immunohistochemistry, and immunoblotting for PAI-1, alpha1/alpha2(I)-procollagen.

RESULTS

Anti-TGF-beta1 significantly reduced TGF-beta1 mRNA (p < 0.05) and PAI-1 expression (p < 0.05). Anti-TGF-beta1 treatment in vivo significantly reduced alpha1(I)-procollagen protein (p < 0.05) and the number of expressing cells (p < 0.05) in contrast to significantly increased (p < 0.05) alpha2(I)-procollagen expression.

CONCLUSION

These results emphasize anti-TGF-beta1 treatment to reduce radiation-induced fibrosis by decreasing alpha1(I)-procollagen synthesis in vivo. alpha1(I)-procollagen and alpha2(I)-procollagen might be differentially regulated by anti-TGF-beta1 treatment. Increased TGF-beta signaling in irradiated skin fibroblasts seemed to be reversible, as shown by a reduction in PAI-1 expression after anti-TGF-beta1 treatment.

Non-syndromic orofacial clefts in Southern Italy: pattern analysis according to gender, history of maternal smoking, folic acid intake and familial diabetes

BACKGROUND

Genetic studies have demonstrated that non-syndromic clefts of the lip, alveolus and palate have an heterogeneous genetic background, and that environmental factors contribute to the onset of this malformation. Therefore studies on different and homogeneous populations can be useful in detecting potentially related environmental and genetic factors.

PURPOSE

The aim of the present study was to evaluate whether gender, folic acid intake, family history of diabetes and/or smoking during pregnancy were associated with a specific type of cleft in a group of patients affected by non-syndromic clefts, collected from Southern Italy.

MATERIAL AND METHODS

Data from one hundred and twenty-six patients were evaluated retrospectively. Each cleft was described as composed by separate antomical entities such as lip, alveolus, primary and secondary palate. None had an isolated alveolar cleft and this was used as internal control. Pattern analysis was used to detect differences in the frequencies of any possible combination of 7 types of clefting stratified according to the studied variables. Data were analysed by comparing observed proportions.

RESULTS

Isolated cleft palate as well as right-sided clefts of lip, alveolus and palate were more frequent in females (p = 0.0014 and 0.0281, respectively), while left sided clefts were more frequent in males (p = 0.0359). A lack of consumption of folic acid was associated with an higher incidence of clefts of the left lip (p = 0.018), while familial diabetes was associated more often with isolated cleft palate (p = 0.0014).

CONCLUSIONS

Gender-related results were comparable with those found in Northern Italy and other countries. Environmentally related results disclosed specific subclasses of clefting associated with lack of folic acid consumption and familial diabetes.

Analysis of polymorphic TGFB1 codons 10, 25, and 263 in a German patient group with non-syndromic cleft lip, alveolus, and palate compared with healthy adults

Background

Clefts of the lip, alveolus, and palate (CLPs) rank among the most frequent and significant congenital malformations. Leu10Pro and Arg25Pro polymorphisms in the precursor region and Thr263Ile polymorphism in the prodomain of the transforming growth factor β1 (TGF-β1) gene have proved to be crucial to predisposition of several disorders.

Methods

In this study, polymorphism analysis was performed by real-time polymerase chain reaction (LightCycler) and TGF-β1 levels determined by enzyme-linked immunosorbent assay.

Results

Only 2/60 Caucasian non-syndromic patients with CLP (3.3%) carried the Arg25Pro and another 2/60 patients (3.3%) the Thr263Ile genotypes, whereas, in a control group of 60 healthy Caucasian blood donors, these heterozygous genotypes were more frequent 16.7% having Arg25Pro (10/60; p < 0.035) and 10,0% having Thr263Ile (6/60), respectively. TGF-β1 levels in platelet-poor plasma of heterozygous Arg25Pro individuals were lower than those of homozygous members (Arg25Arg) in the latter group, but this discrepancy narrowly failed to be significant. Although polymorphisms in codon 10 and 25 were associated with each other, no difference was found between patients and controls concerning the Leu10Pro polymorphism.

Conclusions

The genetic differences in codons 25 and 263 suggest that TGF-β1 could play an important role in occurrence of CLP, however, functional experiments will be required to confirm the mechanisms of disturbed development.

Recent developments in orofacial cleft genetics

Nonsyndromic cleft of the lip and/or palate (CLP or orofacial cleft) derives from an embryopathy with consequent failure of the nasal process and/or palatal shelves fusion. This severe birth defect is one of the most common malformations among live births. Nonsyndromic CLP is composed of two separate entities: cleft lip and palate (CL+/-P) and cleft palate only (CPO). Both have a genetic background, and environmental factors probably disclose these malformations. In CL+/-P, several loci have been identified, and, in one case, a specific gene has also been found. In CPO, one gene has been identified, but many more are probably involved. Because of the complexity of the genetics of nonsyndromic CLP as a result of the difference between CL+/-P and CPO, heterogeneity of each group caused by the number of involved genes, type of inheritance, and interaction with environmental factors, we discuss the more sound results obtained with different approaches: epidemiological studies, animal models, human genetic studies, and in vitro studies.

TGF-beta-3 promotes scarless repair of cleft lip in mouse fetuses

TGF-beta3 mediates epithelial-mesenchymal transformation during normal fusion of lip and palate, but how TGF-beta3 functions during cleft lip repair remains unexplored. We hypothesize that TGF-beta3 promotes fetal cleft lip repair and fusion by increasing the availability of mesenchymal cells. In this investigation, we demonstrated that cleft lips in mouse fetuses were repaired by fetal surgery, producing scarless fusion. At the site of the operation, we first observed an infusion of platelets expressing TGF-beta3, followed by increased expression of cyclin D1 and tenascin-C, and coupled with increased mesenchymal cell proliferation. In an ex vivo serumless culture system, cleft lip explants fused in the presence of exogenous TGF-beta3. Cultured lips also showed up-regulation in cyclin D1 and tenascin-C expression. These findings suggest that microsurgical repair of cleft lip in the fetus that produced scarless fusion is mediated by TGF-beta3 regulation of mesenchymal cell proliferation and migration at the site of repair.