Sheihk Zayed Institute for Pediatric Surgical Innovation, Children's National Medical Center, Washington, DC 20010, USA.
J Pediatr Surg. 2013 Oct;48(10):2047-53. doi: 10.1016/j.jpedsurg.2013.03.047.
Our previous work demonstrated that the transforming-growth factor (TGF) β pathway plays a central role in the liver fibrosis associated with experimental biliary atresia (BA). To confirm these findings in humans, we performed an in silico analysis of publicly available microarray data from liver specimens from children with BA, with the hypothesis that the TGF-β pathway would be dysregulated.
We analyzed publicly available liver gene expression microarray data from 47 infants with BA. We re-analyzed the microarray image files and clinical data to compare gene expression differences between the fibrogenic and inflammatory cohorts identified in the initial study. Targets from the microarray analysis were confirmed using the animal model of BA.
Analysis of variance (ANOVA) detected 6903 transcripts (2822 distinct genes) differentially regulated between groups (p < 0.01; fold change >1.2). We used a targeted approach to identified a subgroup of 24 TGF-β-related transcripts. Expressions for procollagen transcripts were increased in the fibrogenic group (1.2-fold to 1.4-fold); expression of matrix metalloproteinase (MMP)-7 was similarly increased 2-fold, while MMP-9 and plasminogen activator inhibitor-1 were decreased 2-fold and 3-fold respectively. Integrins β5 (1.18-fold) and β8 (1.84-fold) also demonstrated increased expression in the fibrogenic group. Increased expression of β5 (3-fold) and β8 (5-fold) as well as Smad-3 (4-fold) and Smad interacting protein (SIP)-1 (3.5-fold) mRNA was confirmed in experimental BA. Phosphorylated Smad-3 protein in the experimental group was also nearly twice that of the control group, further implicating the TGF-β pathway.
Gene transcripts for known upstream and downstream TGF-β mediators are differentially expressed in liver specimens from children with BA and a fibrogenic gene signature. The same integrins that were dysregulated in the human specimens were also found to be up-regulated in our animal BA model, as were other intermediaries in the TGF-β pathway. Further investigation into whether these mediators may be attractive targets for future therapy in children with BA is warranted.
我们之前的研究表明，转化生长因子 (TGF)β 通路在实验性胆道闭锁 (BA) 相关的肝纤维化中起着核心作用。为了在人类中证实这些发现，我们对来自患有 BA 的儿童的肝组织的公开可用的微阵列数据进行了计算机分析，假设 TGF-β 通路会失调。
我们分析了来自 47 名 BA 患儿的公开可用的肝脏基因表达微阵列数据。我们重新分析了微阵列图像文件和临床数据，以比较初始研究中确定的纤维化和炎症队列之间的基因表达差异。使用 BA 的动物模型证实了微阵列分析的靶标。
方差分析 (ANOVA) 检测到 6903 个转录本（2822 个不同基因）在组间差异调节（p < 0.01；倍数变化 >1.2）。我们使用靶向方法鉴定了 24 个 TGF-β 相关转录本的亚组。纤维化组中前胶原转录本的表达增加（1.2 倍至 1.4 倍）；MMP-7 的表达也增加了 2 倍，而 MMP-9 和纤溶酶原激活物抑制剂-1 分别减少了 2 倍和 3 倍。整合素β5（1.18 倍）和β8（1.84 倍）在纤维化组中也表现出增加的表达。在实验性 BA 中，β5（3 倍）和β8（5 倍）以及 Smad-3（4 倍）和 Smad 相互作用蛋白（SIP）-1（3.5 倍）mRNA 的表达增加得到了证实。实验组磷酸化 Smad-3 蛋白也几乎是对照组的两倍，这进一步表明 TGF-β 通路的存在。
在患有 BA 的儿童的肝组织标本中，已知的 TGF-β 介质的上游和下游基因转录本的表达不同，并且存在纤维化基因特征。在人类标本中失调的相同整合素也在我们的动物 BA 模型中被发现上调，TGF-β 途径中的其他中间介质也是如此。进一步研究这些介质是否可能成为未来 BA 患儿治疗的有吸引力的靶点是值得的。
