Study On The Correlation Between SMURF Gene And Neural Tube Defects And The Occurrence Of MiRNA On Neural Tube Defects

Neural tube defects (NTDs) are a series of common central neural system defects caused by a complete or partial failure of neural tube closure between gestational week2to week6. The most common forms of NTDs are craniorachischisis, spina bifida, myelomeningocele, exencephaly, anencephaly, encephalocele, etc. To find the association between genes and human NTDs, many studies focused on screening mutations in coding regions and SNPs in noncoding regions. These studies provided the molecular diagnosis theory of these complex diseases. And they could benefit to families and society through primary prevention.Planar cell polarity (PCP) plays an important role in convergent extension during neural tube formation. Many animal models showed that knockout of core genes in PCP could cause NTDs. These phenotypes can also be found in Smurf knockout mice. Biochemical experiments showed Smurf targeted Prickle, a core gene of PCP, for ubiquitin-mediated degradation. This is the first case-control study in finding the association between SMURF and human NTDs. Three rare mutations (c.2142G>A, c.1629-92G>A, c.2274+45T>C) were found in NTDs patients. Case-control study demonstrated that allele G in SMURF1rs219797(c.498C>G) was significantly associated with NTDs. In dominant mode, individuals with G/C or G/G genotype had1.92-fold risk to be affected by NTDs compared to individuals with C/C (OR=1.92,95%CI=1.29-2.86, P=0.001). In dominant mode, as an protective factor, allele T in SMURF1rs219826(c.1031+46T>C) was significantly associated with NTDs. Individuals with C/T or T/T genotype had0.67-fold risk to be affected by NTDs compared to individuals with C/C (OR=0.67,95%CI=0.45-0.99, P=0.047). There were rare mutations and SNPs in SMURF1associated with NTDs, which indicated SMURF1associated with an increased risk of NTDs.ZIC2is a member of ZIC finger family which contains5zinc finger proteins in mammals. Zic2knockdown mice exhibit a spectrum of NTDs including spina bifida, anencephaly and exencephaly. We performed mutation analysis in ZIC2in Chinese NTDs patients. We found a synonymous mutation, no missense mutation or deletion. These results demonstrated that in Chinese cohort ZIC2are not a major risk factor for NTDs. This result is consisted with the previous study of ZIC2in other races.MicroRNAs(miRNAs) are single-stranded non-coding RNA that possess17-24nucleotides and repress the translation or cleavage of target gene’s mRNA by base pairing of3’untranslated regions(UTR). We found a NTDs patient specific3bp deletion in DACT13’UTR and predicted miRNA candidates in the position. We used luciferase to find whether this is a functional deletion in miRNA pairing. But we didn’t find any miRNA that downregulated luciferase expression. The results indicated that this deletion might not have an impact on miRNA base pairing.Zebra fish is another common model animal in studying neural tube development and NTDs. Former study found Zebra fish injected in hsa-let-7c showed NTDs. Here we used luciferase to find whether the target gene of hsa-let-7c is one of the core genes in PCP. And finally our study provided a preliminary result that VANGL2might be a target gene of hsa-let-7c.