University of Groningen, University Medical Center Groningen, Department of Internal Medicine, Division of Vascular Medicine, Groningen, The Netherlands.
University of Groningen, University Medical Center Groningen, Department of Rheumatology and Clinical Immunology, The Netherlands.
J Autoimmun. 2024 Sep;148:103297. doi: 10.1016/j.jaut.2024.103297. Epub 2024 Aug 4.
Systemic sclerosis-interstitial lung disease (SSc-ILD) is the leading cause of death in SSc, affecting around 50 % of the patients. Lung tissue of patients with early-stage SSc-ILD is characterized by a predominant inflammatory response with inconspicuous fibrosis, which may progress to honeycombing fibrosis. Hence, a better understanding of the molecular mechanisms underpinning SSc-ILD pathogenesis is needed to improve treatment options and progression prediction. This transcriptomic study aims to reveal the differential gene expression between control (ctrl) lung tissue and inflammatory, prefibrotic and fibrotic lung tissue to capture progression of early to late phase SSc-ILD.
Twelve explanted lungs from patients with SSc-ILD were used to analyze gene expression from formalin-fixed paraffin-embedded lung tissues with varying stages of ILD (n = 18) and control lung tissue (n = 6). The SSc-ILD tissues were stratified into three ROIs: inflammatory, prefibrotic, and fibrotic using histological assessments to define a longitudinal simulation of early to late phases of SSc-ILD. The nanoString (nS) nCounter Human Fibrosis Panel was used to profile the transcriptome in the regions of interest. Validation of potential targetswas performed with immunohistochemistry in the same tissues that were used for transcriptome analysis.
To validate our simulation model, we performed subgroup analysis that showed an incremental increase in pathway scores related to the severity of fibrosis. Ctrl vs SSc-ILD comparison demonstrated 24 differentially expressed genes, two of which had the most pronounced p-values. Cyclin-dependent kinase inhibitor (cdkn2c) was overexpressed (P = 0.00052) in SSc-ILD compared to ctrl, while expression of Pellino E3 ubiquitin-protein ligase 1 (peli1) showed lower expression (P = 0.0012). Additionally, in all four groups, cdkn2c and peli1 gene expression showed an incremental increase and decrease, respectively. Immunohistochemistry of cdkn2c showed consistent results with the nS analysis.
More cdkn2c and less peli1 expression were associated with more advanced stages of SSc-ILD on histologic assessment. We report the potential of the cell cycle inhibitor and senescence marker, cdkn2c (p18) to be associated with fibrosis progression.
系统性硬皮病-间质性肺病（SSc-ILD）是 SSc 的主要致死原因，影响约 50%的患者。早期 SSc-ILD 患者的肺组织以炎症反应为主，纤维化不明显，可能进展为蜂窝状纤维化。因此，需要更好地了解 SSc-ILD 发病机制的分子机制，以改善治疗选择和预测疾病进展。本转录组学研究旨在揭示对照（ctrl）肺组织与炎症、前纤维化和纤维化肺组织之间的差异基因表达，以捕获早期至晚期 SSc-ILD 进展。
使用来自 SSc-ILD 患者的 12 个已切除肺组织，分析福尔马林固定石蜡包埋肺组织中具有不同ILD 阶段（n=18）和对照肺组织（n=6）的基因表达。SSc-ILD 组织使用组织学评估分为三个 ROI：炎症、前纤维化和纤维化，以定义 SSc-ILD 早期至晚期的纵向模拟。nanoString（nS）nCounter 人类纤维化面板用于分析感兴趣区域的转录组。在用于转录组分析的相同组织中，通过免疫组织化学验证潜在靶标的验证。
为了验证我们的模拟模型，我们进行了亚组分析，结果显示与纤维化严重程度相关的途径评分逐渐增加。Ctrl 与 SSc-ILD 比较显示 24 个差异表达基因，其中两个具有最显著的 P 值。与对照相比，细胞周期蛋白依赖性激酶抑制剂（cdkn2c）在 SSc-ILD 中过度表达（P=0.00052），而 Pellino E3 泛素蛋白连接酶 1（peli1）的表达降低（P=0.0012）。此外，在所有四个组中，cdkn2c 和 peli1 的基因表达均呈递增趋势。cdkn2c 的免疫组织化学结果与 nS 分析一致。
在组织学评估中，cdkn2c 的表达增加和 peli1 的表达减少与 SSc-ILD 的更晚期阶段相关。我们报告细胞周期抑制剂和衰老标志物 cdkn2c（p18）与纤维化进展相关的潜力。
