The cranial neural crest plays a fundamental role in orofacial development and morphogenesis. Accordingly, mutations with impact on the cranial neural crest and its development lead to orofacial malformations such as cleft lip and palate. As a pluripotent and dynamic cell population, the cranial neural crest undergoes vast transcriptional and epigenomic alterations throughout the formation of facial structures pointing to an essential role of factors regulating chromatin state or transcription levels. Using CRISPR/Cas9-guided genome editing and conditional mutagenesis in the mouse, we here show that inactivation of Kat5 or Ep400 as the two essential enzymatic subunits of the Tip60/Ep400 chromatin remodeling complex severely affects carbohydrate and amino acid metabolism in cranial neural crest cells. The resulting decrease in protein synthesis, proliferation and survival leads to a drastic reduction of cranial neural crest cells early in fetal development and a loss of most facial structures in the absence of either protein. Following heterozygous loss of Kat5 in neural crest cells palatogenesis was impaired. These findings point to a decisive role of the Tip60/Ep400 chromatin remodeling complex in facial morphogenesis and lead us to conclude that the orofacial clefting observed in patients with heterozygous KAT5 missense mutations is at least in part due to disturbances in the cranial neural crest.
Animals ; Mice ; Chromatin Assembly and Disassembly ; Cleft Lip/genetics* ; Cleft Palate/genetics* ; DNA Helicases/metabolism* ; DNA-Binding Proteins ; Neural Crest/metabolism* ; Skull ; Transcription Factors/metabolism*

Objective: To explore the molecular mechanism of cleft palate in mice induced by 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD). Methods: The pregnant mice were randomly divided into TCDD-treated group (n=42) and control group (n=42). TCDD-treated group was given by gavage a single dose of TCDD (64 μg/kg) at 8: 00 AM on gestation day 10 (GD10) and the control group was given by gavage the isopyknic corn oil. At GD13-GD15, the fetal mice palate development was observed by HE staining. The mouse embryonic palatal mesenchymal cell proliferation was detected by 5-bromo-2-deoxyuridine (BrdU) immunofluorescence. The localization and expression of maternally expressed gene3 (MEG3) in mouse embryonic palatal mesenchymal cells was detected by situ hybridization and real-time PCR (RT-PCR). The key protein expressions of transforming growth factor-β (TGF-β)/Smad signaling pathway in mouse embryonic palatal mesenchyme were analyzed by Western blotting. The interaction of MEG3 and TGF-β receptor Ⅰ (TGF-βRⅠ) was examined by RNA binding protein immunoprecipitation (RIP). Results: At GD13 and GD14, compared with the control group, the ratio of BrdU-positive cells in the palatal mesenchyme of TCDD-treated fetuses decreased significantly (GD13, t=6.66, P=0.003; GD14, t=6.56, P=0.003). However, at GD15, the ratio of BrdU-positive cells was significantly increased (t=-5.98, P=0.004). MEG3 was mainly expressed in the nuclei of fetal mouse palatal mesenchymal cells, and the expression of MEG3 in TCDD group was significantly increased at GD13, GD14 and GD15(GD13, t=39.28, P=0.012; GD14, t=18.75, P=0.042; GD15, t=28.36, P=0.045). At GD14, TCDD decreased the levels of p-Smad2 and Smad4 in embryonic palate mesenchymal cells (p-Smad2, t=9.48, P=0.001;Smad4, t=63.10, P=0.001), whereas the expression of Smad7 was significantly increased at GD14 (t=30.77, P<0.001). The results of the RIP experiment showed that the amount of TGF-βRⅠ-bound MEG3 in mouse embryonic palatal mesenchymal cells in the TCDD group (23.940±1.301) was higher than that in the control group (8.537±1.523)(t=24.55, P<0.001). Conclusions: MEG3 is involved in the suppression of mouse embryonic palatal mesenchymal cell proliferation, functioning at least in part via interacting with the TGF-βRⅠ protein and thereby suppressing Smad signaling in the context of TCDD induced cleft palate.
Animals ; Bromodeoxyuridine ; Cleft Palate/genetics* ; Female ; Mice ; Mice, Inbred C57BL ; Palate/metabolism* ; Polychlorinated Dibenzodioxins/toxicity* ; Pregnancy

This study investigated the role of long non-coding RNAs (lncRNAs) in the development of the palatal tissues. Cleft palates in mice were induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Expression levels of long non-coding RNA H19 (lncRNA H19) and insulin-like growth factor 2 (IGF2) gene were measured by quantitative real-time polymerase chain reaction (qRT-PCR). The rate of occurrence of cleft palate was found to be 100% by TCDD exposure, and TCDD could cause short upper limb, cerebral fissure, webbed neck, and short neck. The expression levels of lncRNA H19 and IGF2 gene specifically showed embryo age-related differences on E13, E14, and E15 in the palatal tissues. The expression levels of lncRNA H19 and IGF2 gene showed an inverse relationship on E13, E14, and E15. These findings demonstrated that lncRNA H19 and IGF2 can mediate the development of mouse cleft palate.
Animals ; Cleft Palate ; chemically induced ; genetics ; pathology ; Female ; Gene Expression Regulation ; Gene Expression Regulation, Developmental ; drug effects ; Male ; Mice ; Mice, Inbred C57BL ; Palate ; metabolism ; Polychlorinated Dibenzodioxins ; toxicity ; RNA, Long Noncoding ; genetics ; Real-Time Polymerase Chain Reaction

We used Smo siRNA to inhibit hedgehog signaling pathway in embryonic day (E) 13 palatal shelves in organ culture. SiRNA 4 was chosen as the most efficient from four synthesized Smo siRNAs. Palatal shelf fusion rate of 4 μg/mL cyclopamine group was the lowest and significantly lower than that of blank control group (P<0.05), and that of siRNA 4 group was also lower than that of blank control group (P=0.183). At 48 h after transfection, Smo protein level of siRNA 4 group was 64.8% lower than that of blank control group (P<0.05), and Gli1 protein level of 4 μg/mL cyclopamine group was 68.9% lower than that of blank control group (P<0.05). Hedgehog signaling pathway inhibition decreased palatal fusion in organ culture, probably owing to downregulation of Smo and Gli1 proteins.
Animals ; Hedgehog Proteins ; genetics ; metabolism ; Kruppel-Like Transcription Factors ; genetics ; metabolism ; Mice ; Nerve Tissue Proteins ; genetics ; metabolism ; Palate ; embryology ; metabolism ; RNA, Small Interfering ; genetics ; metabolism ; Signal Transduction ; Zinc Finger Protein Gli2 ; Zinc Finger Protein Gli3

NSCL/P is a common congenital defect and gene-environmental factors involve in this disorder. Periconceptional intake of folate may reduce the risk of NSCL/P. The present study investigated three SNPs (rs1801198, rs955516, and rs3733890) in three folate pathway genes, including TCN2, MTR, and BHMT among 481 patients and 558 healthy subjects. Rs955516 showed allelic association with NSCL/P. More patients carry rs955516 AA and rs3733890 AA genotypes. The gene-gene interaction test showed trans-phase combination effects for MTR and BHMT genes. Our study suggests that the interaction of MTR and BHMT genes play a vital role in the pathogenesis of NSCL/P in Chinese population.
Adolescent ; Adult ; Brain ; abnormalities ; Child ; Child, Preschool ; China ; epidemiology ; Cleft Lip ; epidemiology ; genetics ; Cleft Palate ; epidemiology ; genetics ; Female ; Folic Acid ; metabolism ; Genotype ; Humans ; Infant ; Male ; Polymorphism, Single Nucleotide ; Young Adult

OBJECTIVEThe glucocorticoid dexamethasone (DEX) can induce palatal cleft; however, the mechanism involved remains unclear. E-cadherin is an important cell adhesion molecule, and it can significantly affect cell fate and embryonic development. Recent studies have indicated that E-cadherin expression in palatal epithelial cells is suppressed in normal palate fusion. This study aimed to determine whether the change in E-cadherin expression is related to the incidence of cleft palate in DEX-induced mice.

METHODSMice were divided into the experimental group and the control group. Pregnant mice were injected with DEX on E10.0-E12.0, whereas mice in the control group were injected with normal saline. Hematoxylin and eosin (HE) staining, immunohistochemistry, and real-time quantitative polymerase chain reaction were employed to evaluate the effect of DEX on fetal mouse palatal processes, particularly the changes in E-cadherin and β-catenin expression levels in the phases of the experimental and control groups.

RESULTSData indicated that the incidence of cleft palate in the DEX group was 43.59% (17/39), whereas that in the control group was only 3.03% (1/33). The results of HE staining showed that the obviously shortened palatal processes could not contact and fuse with one another in the DEX-treated mice model compared with those in the control group. The ectopic expression of E-cadherin in embryonic palatal mesenchymal cells was also analyzed. The expression levels of E-cadherin and β-catenin in the experimental group were higher than those in the control group.

CONCLUSIONThese findings indicated that DEX could induce E-cadherin gene upregulation and ectopic expression, as well as high β-catenin expression, thereby inhibiting the growth of mesenchyme cells and cleft palate.

Animals ; Cadherins ; genetics ; metabolism ; Cleft Palate ; chemically induced ; embryology ; Dexamethasone ; adverse effects ; Disease Models, Animal ; Epithelial Cells ; Female ; Glucocorticoids ; Immunohistochemistry ; Mice ; Pregnancy ; beta Catenin ; metabolism

OBJECTIVETo explore the role of histone H3 acetylation in cleft palate induced by 2, 3, 7, 8-Tetrachlorodibenzo-p-dioxin (TCDD) in C57BL/6J mice, and its mechanism.

METHODSOn gestation day 10 (GD10), 36 pregnant mice were randomly divided into two groups as the treated group(n = 18) and the control group( n = 18). The mice in the treated group received intragastric administration with TCDD 28 μg/kg, while the mice in the control group received equivalent corn oil. The pregnant mice were sacrificed on GD13. 5, GD14. 5 and GD15. 5, collecting fetal palates to determine the activities of histone acetyltransferases (HATs) by Colorimetric and the expression level of acetylated histone H3 (Acetylated histone H3, Ac-H3) by Western-blot.

RESULTSThe activity of HATs was 0.409 7 ± 0.0147, 0.522 3 ± 0.017 1 and 0.643 5 ± 0.013 9 in control group on GD13.5, GD14.5 and GD15.5; 0.865 0 ± 0.0129, 0.719 1 ± 0.017 8 and 0.551 2 ± 0.016 8 in TCDD group. The activity of HATs in TCDD group was higher than that in control group on GD13. 5, GD14. 5, showing significantly difference between the two groups (t = - 56. 932, t = - 19. 516, P < 0.01); however, the activity of HATs in TCDD group was significantly lower than that in control group on GD15. 5 (t = 10. 382, P < 0.01). The expression level of Ac-H3 was 0.745 0 ± 0.113 5, 1.055 9 ± 0.249 4 and 1.795 5 ± 0.081 9 in control group on GD13. 5, GD14. 5 and GD15. 5; while 1.4490 ± 0. 1460, 1. 641 8 ± 0.099 7 and 1. 512 1 ± 0. 150 2 in TCDD group. The expression of Ac-H3 in TCDD group was higher than that in control group on GD13. 5, GD14. 5, showing significantly difference( t = -6. 593, -3. 779, P <0. 01, P <0.05) ; However, the expression of Ac-H3 in TCDD group was statistically lower than that in control group (t = 2. 870, P <0. 05).

CONCLUSIONThe acetylation of histone H3 was involved in the cleft palate of C57BL/6J mice induced by TCDD, which may be one of the mechanisms in TCDD-induced cleft palate.

Acetylation ; drug effects ; Acetyltransferases ; metabolism ; Animals ; Cleft Palate ; chemically induced ; metabolism ; Dioxins ; Female ; Fetus ; Histones ; metabolism ; Humans ; Mice ; Mice, Inbred C57BL ; Polychlorinated Dibenzodioxins ; Pregnancy ; Random Allocation ; Teratogens

OBJECTIVE: To observe the effects of different maintain doses of Dexmedetomidine on plasma cortisol and glucose during anesthesia recovery period in patients undergoing uvulopalatopharyngoplasty under sevoflurane inhalation anesthesia. METHOD: In this prospective, randomized, double-blind study, 120 ASA I and II patients undergoing selective uvulopalatopharyngoplasty under general anesthesia were included. The patients were randomly allocated to three groups (n = 40): Dexmedetomidine low maintain dose group (D1), Dexmedetomidine high maintain dose group (group D2) and control group (group C). The Dexmedetomidine groups and control group were given Dexmedetomidine 1 microg/kg and normal saline in 20 ml within 15 min just before induction of anesthesia. Then Dexmedetomidine were maintained at 0.2 microg x kg(-1) x h(-1) and 0.7 microg x kg(-1) x h(-1) in group D1 and group D2 and were withdrawed 5 min before the end of operation, the same maintained speed of normal saline was given in group C. BIS value was maintained at 40-60 by adjusting the inhaled concentration of sevoflurane. Anesthetic was withdrawed 10 min before the end of operation. Thus, plasma cortisol concentration and blood glucose was needed to be detected just before anesthesia (T0), tracheal extubation (T1), 5 min after extubation (T2) and 15 min after extubation (T3). Duration of operation and anesthesia, consumption of sevoflurane, emergence time, extubation time, the occurrence of dysphoria, bucking and hypoxemia (SpO2 < 90%) during extubation were recorded. RESULT: Compared with group C, MAP and HR at T1, plasma cortisol concentration and blood glucose at T1 - T3 were all significantly lower in group D1 and group D2 (P < 0.05), and so were the consumption of sevoflurane and the occurrence of dysphoria (P < 0.05). The emergence time and extubation time were significantly prolonged in group D2 compared with group D1 and group C (P < 0.05). There was no significant difference in the occurrence of bucking and hypoxemia in three groups (P > 0.05). CONCLUSION In the patients undergoing UPPP under sevoflurane inhalation anesthesia, Dexmedetomidine infused at 0.2 microg x kg(-1) x h(-1) maintains a stable hemodynamics without respiratory depression, alleviates stress response during extubation and reduces both the consumption of sevoflurane and the occurrence of dysphoria without prolonging emergence time and extubation time.
Adult ; Anesthesia Recovery Period ; Anesthesia, Inhalation ; Blood Glucose ; metabolism ; Dexmedetomidine ; administration & dosage ; Double-Blind Method ; Female ; Humans ; Hydrocortisone ; blood ; Hypnotics and Sedatives ; administration & dosage ; Male ; Methyl Ethers ; Middle Aged ; Otorhinolaryngologic Surgical Procedures ; Palate, Soft ; surgery ; Pharynx ; surgery ; Sevoflurane ; Uvula ; surgery

OBJECTIVETo explore the mechanism of cleft palate in mice induced by 2, 3, 7, 8-Tetrachlorodibenzo-p-dioxin (TCDD).

METHODSOn gestation day 10 (GD 10), 12 pregnant mice were randomly divided into two groups as the treated group and the control group with 6 mice in each group. The mice in the treated group received intragastric administration with 64 microg TCDD/kg, while the mice in the control group received equivalent corn oil. The embryos were examined under stereomicroscope to detect the incidence of cleft palate on GD 18.5. Another 18 pregnant mice were randomly divided into two groups (treated group and control group) on GD 10 with 9 pregnant mice in each group. Then each group was divided into 3 subgroups: GD 13.5, GD 14.5 and GD 15.5, with 3 pregnant mice in each subgroup. The palatal shelves were dissected from the embryos for RNA and DNA extraction on GD 13.5, GD 14.5 and GD 15.5. At last the expression of Smad 2-4 and Smad 7 mRNA was investigated by RT-PCR, and the TGF-beta3 promoter methylamine levels were investigated by methylation specific PCR (MSP).

RESULTSThe cleft palate mice model was established successfully by exposing pregnant C57BL/6J mice to TCDD. Total frequency of clefts was 100% in TCDD group, and the frequency of clefts was 0 in the control group. The relative expression of Smad 2 mRNA was 0.263 +/- 0.088, 0.296 +/- 0.016 and 0.159 +/- 0.027 in TCDD group, 0.180 +/- 0.042, 0.282 +/- 0.029 and 0.165 +/- 0.018 in control group. The relative expression of Smad 3 mRNA was 0.453 +/- 0.153, 0.551 +/- 0.160 and 0.328 +/- 0.049 in TCDD group, 0.375 +/- 0.126, 0.510 +/- 0.145 and 0.259 +/- 0.035 in control group. The relative expression of Smad 4 mRNA was 0.675 +/- 0.174, 0.577 +/- 0.070 and 0.396 +/- 0.066 in TCDD group, 0.557 +/- 0.138, 0.587 +/- 0.080 and 0.441 +/- 0.054 in control group. The relative expression of Smad 7 mRNA was 0.283 +/- 0.050, 0.320 +/- 0.068 and 0.169 +/- 0.045 in TCDD group, 0.207 +/- 0.043, 0.288 +/- 0.051 and 0.155 +/- 0.040 in control group. There was no significant difference between the TCDD treated mice and the control (P > 0.05). The TGF-beta3 promoters were at the un-methylation state both in the TCDD treated and control group.

CONCLUSIONIt suggests that TCDD could induce a stable formation of cleft palate, but it is not through the TGF-beta/Smad signaling nor through the modification of TGF-beta3 promoter methylation.

Animals ; Cleft Palate ; chemically induced ; DNA Methylation ; Female ; Mice ; Mice, Inbred C57BL ; Polychlorinated Dibenzodioxins ; toxicity ; Pregnancy ; Promoter Regions, Genetic ; Signal Transduction ; Smad Proteins ; metabolism ; Teratogens ; toxicity ; Transforming Growth Factor beta3 ; metabolism

OBJECTIVEConvincing evidence suggests a link between increased risk of nonsyndromic cleft lip with or without cleft palate (NSCL/P) and low intake of folic acid by the mother during pregnancy. The present study was designed to explore if genetic variation in the betaine-homocysteine methyltransferase (BHMT) gene contributes to NSCL/P.

METHODSDNA was obtained from 166 individuals with NSCL/P and 285 healthy subjects. Three known single nucleotide polymorphisms (SNPs) present in the BHMT gene (rs651852, rs3797546, and rs3733890) were investigated by real-time PCR-based TaqMan genotyping.

RESULTSNeither allelic nor genotypic association was found between NSCL/P and SNPs rs651852 and rs3733890. SNP rs3797546 did not show allelic association with NSCL/P; however, a higher proportion of NSCL/P patients carry the CC genotype compared with the TT+CT genotype (P=0.020, OR=2.10, 95% CI=1.11-3.95).

CONCLUSIONOur study suggests that polymorphism rs3797546 in the BHMT gene may confer genetic risk of NSCL/P in a recessive manner.

Asian Continental Ancestry Group ; genetics ; Betaine-Homocysteine S-Methyltransferase ; genetics ; metabolism ; Case-Control Studies ; China ; Cleft Lip ; genetics ; Cleft Palate ; genetics ; Gene Expression Regulation ; Genetic Predisposition to Disease ; Genotype ; Humans ; Polymorphism, Single Nucleotide ; Risk Factors