title: Sonic Hedgehog Signaling Affected by Promoter Hypermethylation Induces Aberrant Gli2 Expression in Spina Bifida.
abstract: GLI2 is a key mediator of the sonic hedgehog (Shh) signaling pathway and plays an important role in neural tube development during vertebrate embryogenesis; however, the role of gli2 in human folate-related neural tube defects remains unclear. In this study, we compared methylation status and polymorphisms of gli2 between spina bifida patients and a control group to explore the underlying mechanisms related to folate deficiency in spina bifida. No single nucleotide polymorphism was found to be significantly different between the two groups, although gli2 methylation levels were significantly increased in spina bifida samples, accompanied by aberrant GLI2 expression. Moreover, a prominent negative correlation was found between the folate level in brain tissue and the gli2 methylation status (r = -0.41, P = 0.014), and gli2 hypermethylation increased the risk of spina bifida with an odds ratio of 12.45 (95 % confidence interval: 2.71-57.22, P = 0.001). In addition, we established a cell model to illustrate the effect of gli2 expression and the accessibility of chromatin affected by methylation. High gli2 and gli1 mRNA expression was detected in 5-Aza-treated cells, while gli2 hypermethylation resulted in chromatin inaccessibility and a reduced association with nuclear proteins containing transcriptional factors. More meaningful to the pathway, the effect gene of the Shh pathway, gli1, was found to have a reduced level of expression along with a decreased expression of gli2 in our cell model. Aberrant high methylation resulted in the low expression of gli2 in spina bifida, which was affected by the change in chromatin status and the capacity of transcription factor binding.
authors.affiliation: Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Beijing, 100020, China.
authors.forename: Xiao-Lin
authors.initials: XL
authors.lastname: Lu
authors.affiliation: Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Beijing, 100020, China. lily_wang@yeah.net.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Beijing, 100020, China.
authors.forename: Shao-Yan
authors.initials: SY
authors.lastname: Chang
authors.affiliation: Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Beijing, 100020, China.
authors.forename: Shao-Fang
authors.initials: SF
authors.lastname: Shangguan
authors.affiliation: Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Beijing, 100020, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Beijing, 100020, China.
authors.forename: Li-Hua
authors.initials: LH
authors.lastname: Wu
authors.affiliation: Department of Pathology, Capital Institute of Pediatrics, Beijing, 100020, China.
authors.forename: Ji-Zhen
authors.initials: JZ
authors.lastname: Zou
authors.affiliation: Department of Pathology, Capital Institute of Pediatrics, Beijing, 100020, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Xiao
authors.affiliation: Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Beijing, 100020, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Li
authors.affiliation: Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Beijing, 100020, China.
authors.forename: Yi-Hua
authors.initials: YH
authors.lastname: Bao
authors.affiliation: Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Beijing, 100020, China.
authors.forename: Z-Y
authors.initials: ZY
authors.lastname: Qiu
authors.affiliation: Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Beijing, 100020, China. zhangtingcv@126.com.
authors.forename: Ting
authors.initials: T
authors.lastname: Zhang
mesh_terms: D000328:Adult; D001921:Brain / Q000378:metabolism / Q000473:pathology; D016022:Case-Control Studies; D002843:Chromatin / Q000378:metabolism; D019175:DNA Methylation / Q000235:genetics*; D005260:Female; D005492:Folic Acid / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D053823:Hedgehog Proteins / Q000378:metabolism*; D006801:Humans; D008297:Male; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D016135:Spinal Dysraphism / Q000235:genetics*; D014158:Transcription, Genetic; D000071676:Zinc Finger Protein GLI1 / Q000235:genetics / Q000378:metabolism; D000075746:Zinc Finger Protein Gli2 / Q000235:genetics* / Q000378:metabolism
chemical_list: D002843:Chromatin; C400551:GLI1 protein, human; C082593:GLI2 protein, human; D053823:Hedgehog Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; C509239:SHH protein, human; D000071676:Zinc Finger Protein GLI1; D000075746:Zinc Finger Protein Gli2; D005492:Folic Acid
keywords: Methylation; Sonic hedgehog pathway; Spina bifida; gli2