Gastroenterology Department, Algarve University Hospital Center [CHUA], Portimão, Portugal.
ABC-Algarve Biomedical Center, University of Algarve, Faro, Portugal.
J Crohns Colitis. 2024 Nov 4;18(11):1741-1752. doi: 10.1093/ecco-jcc/jjae064.
Stricturing [B2] and penetrating [B3] ileal Crohn's disease have been reported to present similar levels of histopathological transmural fibrosis. This study aimed to compare the fibrosis-related transcriptomic profiles of penetrating and stricturing ileal Crohn's disease.
Using Nanostring technology and comparative bioinformatics, we analysed the expression of 787 fibrosis-related genes in 36 ileal surgical specimens, 12 B2 and 24 B3, the latter including 12 cases with associated stricture[s] [B3s] and 12 without [B3o]. Quality control of extracted RNA was performed according to Nanostring parameters and principal component analysis for the distribution analysis. For the selection of the differentially expressed genes, a p-adjusted <0.05 and fold change ≤-1.5 or ≥1.5 were adopted. Quantitative polymerase chain reaction (qPCR) and immunohistochemistry analyses were used to validate selected differentially expressed genes.
We included 34 patients with B2 and B3 phenotypes, balanced for age at diagnosis, age at surgery, gender, Crohn's disease localisation, perianal disease, and therapy. Inflammation and fibrosis histopathological scoring were similar in all cases. B2 and B3 groups showed a very good clustering regarding 30 significantly differentially expressed genes, all being remarkably upregulated in B3. More than half of these genes were involved in Crohn's disease fibrogenesis, and eight differentially expressed genes were so in other organs. The most significantly active biological processes and pathways in penetrating disease were response to TGFβ and matrix organisation and degradation, as validated by immunohistochemistry.
Despite the histopathological similarities in fibrosis between stricturing and penetrating ileal Crohn's disease, their fibrosis-related transcriptomic profiles are distinct. Penetrating disease exhibits a distinctive transcriptomic landscape related to enhanced matrix remodelling.
狭窄[B2]和穿透[B3]回肠克罗恩病的组织病理学透壁纤维化程度被报道相似。本研究旨在比较穿透性和狭窄性回肠克罗恩病的纤维化相关转录组谱。
使用 Nanostring 技术和比较生物信息学，我们分析了 36 个回肠手术标本中的 787 个纤维化相关基因的表达，其中 12 个为 B2，24 个为 B3，后者包括 12 例伴狭窄[B3s]和 12 例不伴狭窄[B3o]。根据 Nanostring 参数和主成分分析进行 RNA 提取的质量控制，以分析分布情况。对于差异表达基因的选择，采用了 p 值调整<0.05 和倍数变化≤-1.5 或≥1.5。采用定量聚合酶链反应（qPCR）和免疫组织化学分析来验证所选差异表达基因。
我们纳入了 34 例 B2 和 B3 表型患者，其诊断时年龄、手术时年龄、性别、克罗恩病定位、肛周疾病和治疗均平衡。所有病例的炎症和纤维化组织病理学评分相似。B2 和 B3 组在 30 个显著差异表达基因方面表现出非常好的聚类，所有这些基因在 B3 中均显著上调。这些基因中有一半以上参与了克罗恩病纤维化的发生，其中 8 个差异表达基因在其他器官中也有表达。穿透性疾病中最显著的生物过程和途径是对 TGFβ的反应以及基质组织和降解，这通过免疫组织化学得到了验证。
尽管狭窄性和穿透性回肠克罗恩病的纤维化在组织病理学上相似，但它们的纤维化相关转录组谱是不同的。穿透性疾病表现出独特的与增强的基质重塑相关的转录组图谱。
