摘要
目的在2型糖尿病肾病(DN)白蛋白尿易感基因定位的基础上,进一步筛选白蛋白尿易感基因位点(UA-1)区域附近的候选基因。方法提取20周龄雄性KK/Ta(n=3)和BALB/c(n=2)小鼠肾脏总RNA,应用Affymetrix Murine GenomeU74Av2基因芯片检测肾脏基因表达谱。选择UA-1区域的差异表达基因多配体蛋白聚糖4(syndecan-4),竞争性RT-PCR验证基因芯片的结果。提取KK/Ta、BALB/c小鼠的基因组DNA,进行syndecan.4基因编码区和启动子区域的序列分析。结果在2型糖尿病KK/Ta小鼠UA-1区域附近存在着约10个差异表达基因。其中syndecan-4在20周龄KK/Ta小鼠肾脏中的表达上调,为BALB/c小鼠的26.1倍。在syndecan.4基因编码区存在2个基因多态性,分别为A93C和T216C多态性,2者均为同义突变。在syndecan-4基因启动子区域存在3个基因多态性,分别为-T263C、-T396C与-G669A多态性。TATA框位于转录起始位点上游321bp处,-T263C处恰好为转录因子Clox的结合位点。结论syndecan-4基因位于2型糖尿病UA-1附近区域,在20周龄KK/Ta小鼠肾脏中的表达明显上调,是DN的候选基因。syndecan-4启动子处的基因多态性可能为其差异表达的原因。
Objective To identify the candidate genes in the vicinity of a susceptibility locus (urinary albumin 1, UA-1) contributing to the development of albuminuria in type 2 diabetic KK/Ta mice. Methods Total RNA was extracted from the kidneys of KK/Ta (n=3) and BALB/c (n=2) mice at 20 weeks of age. The gene expression profile in kidney was investigated using the Affymetrix Murine Genome U74Av2 array. Competitive RT-PCR was used to confirm the differential expression of syndecan-4 which located in the vicinity of UA-1. Genome DNA was extracted from KK/Ta and BALB/c mice. DNA sequence analysis of the coding and promotor region of syndecan-4 gene was conducted. Results In the vicinity of the susceptibility locus (UA-1) contributing to the development of albuminuria in type 2 diabetic KK/Ta mice, 10 candidate genes that showed differential expression were identified. Among them, the gene expression of syndecan-4in KK/Ta kidneys at 20 weeks of age was up-regulated by 26.1 times of age-matched BALB/c kidneys. Sequence analysis revealed two synonymous polymorphisms in the coding region (A93C and T216C) and three polymorphisms in the promoter region (-T263C, -T396C and -G669A) of the syndecan-4 gene. The TATA box was found at 321 bp upstream from the transcription start site, and the T263C polymorphism was located in the binding site of transcription factor Clox. Conclusions Syndecan-4 gene is mapped in the vicinity of the susceptibility locus contributing to the development of albuminuria in type 2 diabetes. The gene expression of syndecan-4 in KK/Ta kidneys is up-regulated than that in age-matched BALB/c kidneys at 20 weeks of age. Thus syndeean-4 may be one of the potential candidate genes responsible for diabetic nephropathy. Sequence differences in the promoter region influence the expression levels of syndecan-4 genes in KK/Ta kidneys.
出处
《中华肾脏病杂志》
CAS
CSCD
北大核心
2012年第4期312-317,共6页
Chinese Journal of Nephrology
基金
国家自然科学基金(30700369)
教育部留学回国人员科研启动基金(教外司留[2006]331号)
辽宁省教育厅科学技术研究项目(L2010658)
沈阳市科技计划项目(F11-264-1-38)