Han Bei, Shi Xing, Peng Quan, Gao Wentao
Department of Endocrinology, Nanjing Children's Hospital Affiliated to Nanjing Medical University, Nanjing 210029, China.
ISRN Endocrinol. 2012;2012:630861. doi: 10.5402/2012/630861. Epub 2012 Dec 11.
Genetic susceptibility plays a key role in type 1 diabetes development. Because miR-541 gene was located within the associated chromosome loci and its target genes include the diabetes-associated gene neurogenin3, this study aimed to investigate whether miR-541 had type 1 diabetes-associated genetic variations. Type 1 diabetes children and healthy volunteers were recruited; direct sequencing was performed in initial 69 patients and 46 volunteers. We identified 1 reported SNP (rs12893725) and 3 novel genetic variations, for the candidate -404 G→T variation, restriction fragment length polymorphism (RFLP) was performed in total 247 diabetes children and 212 healthy volunteers, a different distribution trait of allele frequencies was found between the two groups, and further clinical analysis found no significant correlation between clinical parameter and genotypes among patients. In addition, by luciferase reporter assay, -404 was found to be within putative promoter region of pre-miR-541; although mutation of G→T has no effect on promoter activity, a significant secondary structure alteration may possibly influence its processing and transcription. In conclusion, we identified 3 novel genetic variations in putative promoter of miR-541 in type 1 diabetes patients; -404 G→T of miR-541 is a potential T1D-associated genetic variation.
遗传易感性在1型糖尿病的发生发展中起关键作用。由于miR - 541基因位于相关染色体位点内，且其靶基因包括糖尿病相关基因神经生成素3，本研究旨在调查miR - 541是否存在与1型糖尿病相关的基因变异。招募了1型糖尿病儿童和健康志愿者；对最初的69例患者和46名志愿者进行了直接测序。我们鉴定出1个已报道的单核苷酸多态性（rs12893725）和3个新的基因变异，对于候选的 - 404 G→T变异，在总共247例糖尿病儿童和212名健康志愿者中进行了限制性片段长度多态性（RFLP）分析，发现两组之间等位基因频率的分布特征不同，进一步的临床分析发现患者的临床参数与基因型之间无显著相关性。此外，通过荧光素酶报告基因检测，发现 - 404位于pre - miR - 541的假定启动子区域内；虽然G→T突变对启动子活性没有影响，但显著的二级结构改变可能会影响其加工和转录。总之，我们在1型糖尿病患者中鉴定出miR - 541假定启动子中的3个新基因变异；miR - 541的 - 404 G→T是一个潜在的与1型糖尿病相关的基因变异。
