Yang Yi, Zhou Xin, Gao Hong, Ji Shi Jun, Wang Changlin
Department of Pediatric Surgery and Major Laboratory of Health Ministry for Congenital Malformations, Affiliated 2nd Clinical Hospital, China Medical University, Shenyang City, People's Republic of China.
J Pediatr Surg. 2003 Nov;38(11):1656-60. doi: 10.1016/s0022-3468(03)00577-3.
The aim of this study was to test the hypothesis that expression of epidermal growth factor (EGF) and transforming growth factor-beta 1 (TGF-beta 1) may be altered in stenotic tissue of patients with congenital hydronephrosis caused by pelviureteric junction (PUJ) obstruction and to evaluate the role of these 2 growth factors.
The expression of EGF and TGF-beta 1 was evaluated in tissue specimens in 25 children with PUJ obstruction and 15 controls with normal PUJs by immunohistochemistry, in situ hybridization, and reverse transcriptase polymerase chain reaction (RT-PCR) techniques. All the signals of mRNA products were normalized to the mRNA levels of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) a housekeeping gene, as a ratio.
On RT-PCR study, the amount of TGF-beta 1 mRNA in stenotic tissue was higher than in controls, in addition, EGF gene expression in the obstructed junction was significantly lower than in normal junctions. The TGF-beta 1 to GAPDH ratio was 0.57 +/- 0.26 and 0.36 +/- 0.19 in the stenotic tissue and the normal ureter, respectively (P =.012). The EGF to GAPDH ratio was 0.17 +/- 0.08 and 0.37 +/- 0.14 in the stenotic tissue and the normal ureter, respectively (P =.0001). Furthermore, the positive correlations were found between TGF-beta1 gene and protein expression (r = 0.601; P =.001), TGF-beta 1 gene and drainage clearance half-time (T1/2) (r = 0.474; P =.017), TGF-beta 1 protein expression, and T1/2 (r = 0.516; P =.008). A negative correlation was found between EGF gene and T1/2 (r = -0.448; P =.025). On immunolabeling and in situ hybridization labeling, the expression of TGF-beta 1 protein was strongly positive and confined to the muscle cells, spindle cells, and collagen fibers in the stenotic tissue; the expression of TGF-beta 1 mRNA was moderately positive and mainly distributed in the collagen of the stenotic segment, both the expression of EGF protein and mRNA were negative in the normal ureter.
There were increased TGF-beta 1 mRNA expression and decreased EGF mRNA expression in the stenotic tissue after clinical ureteropelvic junction obstruction. The alteration of EGF and TGF-beta 1 expression may be involved in the pathogenesis of congenital hydronephrosis.
本研究旨在验证以下假设，即由肾盂输尿管连接处（PUJ）梗阻导致的先天性肾积水患者的狭窄组织中，表皮生长因子（EGF）和转化生长因子-β1（TGF-β1）的表达可能发生改变，并评估这两种生长因子的作用。
采用免疫组织化学、原位杂交和逆转录聚合酶链反应（RT-PCR）技术，对25例PUJ梗阻患儿和15例PUJ正常的对照者的组织标本中EGF和TGF-β1的表达进行评估。所有mRNA产物的信号均以管家基因甘油醛-3-磷酸脱氢酶（GAPDH）的mRNA水平作为参照进行标准化，以比值表示。
RT-PCR研究显示，狭窄组织中TGF-β1 mRNA的量高于对照组，此外，梗阻连接处的EGF基因表达显著低于正常连接处。狭窄组织和正常输尿管中TGF-β1与GAPDH的比值分别为0.57±0.26和0.36±0.19（P = 0.012）。狭窄组织和正常输尿管中EGF与GAPDH的比值分别为0.17±0.08和0.37±0.14（P = 0.0001）。此外，发现TGF-β1基因与蛋白表达之间呈正相关（r = 0.601；P = 0.001），TGF-β1基因与引流清除半衰期（T1/2）之间呈正相关（r = 0.474；P = 0.017），TGF-β1蛋白表达与T1/2之间呈正相关（r = 0.516；P = 0.008）。EGF基因与T1/2之间呈负相关（r = -0.448；P = 0.025）。免疫标记和原位杂交标记显示，狭窄组织中TGF-β1蛋白表达呈强阳性，局限于肌细胞、梭形细胞和胶原纤维；TGF-β1 mRNA表达呈中度阳性，主要分布于狭窄段的胶原中，正常输尿管中EGF蛋白和mRNA表达均为阴性。
临床输尿管肾盂连接处梗阻后，狭窄组织中TGF-β1 mRNA表达增加，EGF mRNA表达减少。EGF和TGF-β1表达的改变可能参与先天性肾积水的发病机制。
