Cis and trans regulatory elements in NPHS2 promoter:: Implications in proteinuria and progression of renal diseases
Cis and trans regulatory elements in NPHS2 promoter:: Implications in proteinuria and progression of renal diseases
复制标题
DOI：
10.1038/sj.ki.5001767
复制
发表时间：
2006-10-01
影响因子：
19.6
通讯作者：
Ghiggeri, G. M.
中科院分区：
文献类型：
--
作者：
Di Duca, M.;Oleggini, R.;Ghiggeri, G. M.
足细胞中的Podocin（NPHS 2）表达与不同程度的蛋白尿和不同肾小球疾病中向肾衰竭的进展相关，这表明NPHS 2启动子中的不同表达谱。发现NPHS 2启动子中的三种功能多态性（-51T、-116T和-535insCTTTTTT（3））决定了在足细胞中转染时报告基因表达的强烈下调（分别为-73、-59和-82%）。电泳迁移率变动分析实验表明，所有野生型变异体（-51 G、-116 C和-535 insCTTTTTT（2））与足细胞核提取物形成特异性DNA-蛋白复合物，这些复合物被罕见形式（-51 T、-116 T和-535 insCTTTTTT（3））的存在所消除。在-51 G的情况下，上游刺激因子1（upstream stimulatory factor-1，USF 1）被鉴定为特异性反式元件，雅阁根据USF 1 RNAi沉默。对204例正常对照和545例肾脏疾病患者（308例免疫球蛋白（IG）A肾病和237例局灶节段性肾小球硬化）的单倍型分析证明，在正常和病理组群中，-116/-51和-535/P2OL形成了两个强连锁不平衡区。高NPHS 2启动子谱-116 C/-51 G单倍型在伊加肾病患者中更常见（P值0.005），并且与蛋白尿和肌酐水平方面的更好临床结局相关。总之，我们的研究描述了NPHS 2启动子的功能变体，并表征了调节肾脏中podocin表达的反式作用元件。高产量NPHS 2启动子单倍型似乎在慢性肾小球疾病患者中具有保护作用。
Podocin (NPHS2) expression in podocytes is associated with variable degrees of proteinuria and progression to renal failure in different glomerular diseases that suggests different expression profiles in NPHS2 promoter. Three functional polymorphisms in NPHS2 promoter (-51T, -116T, and -535 insCTTTTTT(3)) were found determining strong downregulation (-73, -59, and -82%, respectively) of the reporter gene expression when transfected in podocytes. Electrophoretic mobility shift assay experiments showed that all wild-type variants (-51G, -116C, and -535 insCTTTTTT(2)) formed specific DNA-protein complexes with podocyte nuclear extracts that were abolished by the presence of the rare forms (-51T, -116T, and -535 insCTTTTTT(3)). In the case of -51G, upstream stimulatory factor-1 (USF1) was identified as the specific trans element in accord to binding inhibition experiments and USF1 RNAi silencing. Haplotype analysis of 204 normal controls and 545 patients with renal diseases (308 immunoglobulin (Ig) A nephropathy and 237 focal segmental glomerulosclerosis) evidenced that -116/-51 and -535/P2OL formed two blocks in strong linkage disequilibrium in both normal and pathological cohorts. The high NPHS2 promoter profile -116C/-51G haplotype was more frequent in patients with IgA nephropathy (P-value 0.005) and was associated with a better clinical outcome in terms of proteinuria and creatinine levels. Overall our study describes functional variants of NPHS2 promoter and characterizes trans-acting elements that modulate podocin expression in the kidney. High producer NPHS2 promoter haplotypes seem protective in patients with chronic glomerular diseases.