Awad M R, El-Gamel A, Hasleton P, Turner D M, Sinnott P J, Hutchinson I V
School of Biological Sciences, University of Manchester, United Kingdom.
Transplantation. 1998 Oct 27;66(8):1014-20. doi: 10.1097/00007890-199810270-00009.
Transforming growth factor (TGF)-beta1 is a profibrogenetic cytokine that has been implicated in the development of fibrosis in transplanted tissues. In this study, we have analyzed the genetic regulation of TGF-beta1 production in lung transplant recipients.
A polymerase chain reaction-single-stranded conformational polymorphism technique was used to detect polymorphisms in the TGF-beta1 gene from genomic DNA. Polymorphisms were shown to correlate with in vitro TGF-beta1 production by stimulated lymphocytes. A single-specific oligonucleotide probe hybridization method was devised to screen for these polymorphisms in lung transplant groups and controls.
We have identified five polymorphisms in the TGF-beta1 gene: two in the promoter region at positions -800 and -509, one at position +72 in a nontranslated region, and two in the signal sequence at positions +869 and +915. The polymorphism at position +915 in the signal sequence, which changes codon 25 (arginine-->proline), is associated with interindividual variation in levels of TGF-beta1 production. Stimulated lymphocytes of homozygous genotype (arginine/arginine) from control individuals produced significantly more TGF-beta1 in vitro (10037+/-745 pg/ml) compared with heterozygous (arginine/proline) individuals (6729+/-883 pg/ml; P<0.02). In patients requiring lung transplantation for a fibrotic lung condition, there was an increase in the frequency of the high-producer TGF-beta1 allele (arginine). This allele was significantly associated with pretransplant fibrotic pathology (P<0.02) (n=45) when compared with controls (n=107) and with pretransplant nonfibrotic pathology (P<0.004) (n=50). This allele was also associated with allograft fibrosis in transbronchial biopsies when compared with controls (P<0.03) and with nonallograft fibrosis (P<0.01).
The production of TGF-beta1 is under genetic control, and this in turn influences the development of lung fibrosis. Hence, the TGF-beta1 genotype has prognostic significance in transplant recipients.
转化生长因子（TGF）-β1是一种促纤维化细胞因子，与移植组织中的纤维化发展有关。在本研究中，我们分析了肺移植受者中TGF-β1产生的基因调控。
采用聚合酶链反应-单链构象多态性技术检测基因组DNA中TGF-β1基因的多态性。多态性与刺激淋巴细胞体外产生TGF-β1相关。设计了一种单特异性寡核苷酸探针杂交方法，用于在肺移植组和对照组中筛选这些多态性。
我们在TGF-β1基因中鉴定出5种多态性：两种位于启动子区域的-800和-509位点，一种位于非翻译区的+72位点，两种位于信号序列的+869和+915位点。信号序列中+915位点的多态性改变了密码子25（精氨酸→脯氨酸），与TGF-β1产生水平的个体差异有关。来自对照个体的纯合基因型（精氨酸/精氨酸）刺激淋巴细胞在体外产生的TGF-β1显著多于杂合子（精氨酸/脯氨酸）个体（10037±745 pg/ml比6729±883 pg/ml；P<0.02）。在因纤维化肺病需要肺移植的患者中，高产生TGF-β1等位基因（精氨酸）的频率增加。与对照组（n=107）和移植前非纤维化病理组（n=50）相比，该等位基因与移植前纤维化病理显著相关（P<0.02）。与对照组相比，该等位基因在经支气管活检中也与同种异体移植纤维化相关（P<0.03），与非同种异体移植纤维化相关（P<0.01）。
TGF-β1的产生受基因控制，这反过来又影响肺纤维化的发展。因此，TGF-β1基因型对移植受者具有预后意义。
