El-Ghoneimi Alaa, Berrebi Dominique, Levacher Beatrice, Nepote Virginie, Infante MurielL, Paris Regine, Simonneau Michel, Aigrain Yves, Peuchmaur Michel
Department of Pediatric Surgery, Hôpital Robert Debré, Paris, France.
J Urol. 2002 Dec;168(6):2624-8. doi: 10.1016/S0022-5347(05)64231-0.
Differentiation of the metanephros is abnormal in cases of renal dysplasia, resulting in abnormal kidney organization. In vitro and in vivo studies indicate that glial cell line derived neurotrophic factor (GDNF) is a major regulator of kidney development and ureteral arborization. Therefore, we investigated the pattern of GDNF gene expression in human dysplastic kidneys.
Specimens of whole tissues of human normal and dysplastic kidneys associated with obstructive uropathy were analyzed for GDNF mRNA by reverse transcriptase-polymerase chain reaction (RT-PCR). Immunohistochemistry with GDNF antibody and laser capture microdissection plus RT-PCR were done to identify cells producing GDNF. Apoptosis, BCL-2 and Ki67 were also studied.
There were few if any GDNF transcripts in normal kidneys, whereas GDNF was over expressed in renal dysplasia specimens. Strong GDNF expression was found in the dysplastic tubules of dysplastic kidneys, whereas peritubular mesenchyma expressed no GDNF protein. Laser capture microdissection/RT-PCR detected GDNF mRNA in epithelial cells isolated from dysplastic tubules but not in cells from the surrounding mesenchyma, which was confirmed by sequence analysis. GDNF expression by epithelial cells was associated with high proliferation, BCL-2 expression and rare apoptosis.
GDNF gene expression is restricted to the tubular epithelium of dysplastic human kidneys. Our results strongly suggest that GDNF not only influences kidney morphogenesis, but is also implicated in abnormal kidney development.
肾发育异常时后肾分化异常，导致肾脏组织结构异常。体外和体内研究表明，胶质细胞系源性神经营养因子（GDNF）是肾脏发育和输尿管分支的主要调节因子。因此，我们研究了GDNF基因在人发育异常肾脏中的表达模式。
采用逆转录聚合酶链反应（RT-PCR）分析人正常肾脏及与梗阻性尿路病相关的发育异常肾脏的全组织标本中的GDNF mRNA。采用GDNF抗体免疫组织化学以及激光捕获显微切割加RT-PCR来鉴定产生GDNF的细胞。同时也研究了细胞凋亡、BCL-2和Ki67。
正常肾脏中几乎没有GDNF转录本，而在发育异常的肾脏标本中GDNF过度表达。在发育异常肾脏的发育异常肾小管中发现了强烈的GDNF表达，而肾小管周围间质未表达GDNF蛋白。激光捕获显微切割/RT-PCR在从发育异常肾小管分离的上皮细胞中检测到GDNF mRNA，但在周围间质细胞中未检测到，序列分析证实了这一点。上皮细胞的GDNF表达与高增殖、BCL-2表达和罕见的细胞凋亡有关。
GDNF基因表达局限于发育异常的人肾脏的肾小管上皮。我们的结果强烈表明，GDNF不仅影响肾脏形态发生，还与肾脏发育异常有关。
