Longitudinal analysis of phenotype-transcriptome correlations in AAV-TGFb1- and Bleomycin-induced lung fibrosis. Longitudinal analysis of phenotype-transcriptome correlations in AAV-TGFb1- and Bleomycin-induced lung fibrosis

We have previously established a novel mouse model of lung fibrosis based on Adeno-associated virus (AAV)-mediated pulmonary overexpression of TGFβ1. Here, we provide an in-depth characterization of phenotypic and transcriptomic changes (mRNA and miRNA) in a head-to-head comparison with Bleomycin-induced lung injury over a 4-week disease course. The analyses delineate the temporal state of model-specific and commonly altered pathways, thereby providing detailed insights into the processes underlying disease development. They further guide appropriate model selection as well as interventional study design. Overall, Bleomycin-induced fibrosis resembles a biphasic process of acute inflammation and subsequent transition into fibrosis (with partial resolution), whereas the TGFβ1-driven model is characterized by pronounced and persistent fibrosis with concomitant inflammation and an equally complex disease phenotype as observed upon Bleomycin instillation. Finally, based on an integrative approach combining lung function data, mRNA/miRNA profiles, their correlation and miRNA target predictions, we identify putative drug targets and miRNAs to be explored as therapeutic candidates for fibrotic diseases. Taken together, we provide a comprehensive analysis and rich data resource based on RNA-sequencing, along with a strategy for transcriptome-phenotype coupling. The results will be of value for TGFβ research, drug discovery and biomarker identification in progressive fibrosing interstitial lung diseases.

我们此前基于腺相关病毒（Adeno-associated virus, AAV）介导的肺部转化生长因子β1（TGFβ1）过表达，构建了一种新型肺纤维化小鼠模型。在此，我们针对为期4周的疾病进程，将该模型与博莱霉素（Bleomycin）诱导的肺损伤模型开展头对头比较，深入表征二者的表型及转录组水平变化（涵盖mRNA与miRNA）。本分析明确了模型特异性及共同失调通路的时序状态，从而为疾病发生的潜在分子过程提供详尽解析。本研究结果还可为合理选择实验模型及干预性研究设计提供指导依据。总体而言，博莱霉素诱导的肺纤维化呈现双相进程：先触发急性炎症，随后进展为纤维化（可出现部分缓解）；而TGFβ1驱动的模型则以显著且持续的纤维化伴随炎症为核心特征，其疾病表型复杂度与博莱霉素滴注诱导的模型相当。最后，我们结合肺功能数据、mRNA/miRNA表达谱、二者相关性分析结果及miRNA靶标预测信息，通过整合分析策略，筛选出可作为纤维化疾病治疗候选靶点的潜在药物靶点及miRNA。综上，本研究基于RNA测序（RNA-sequencing）构建了全面的分析体系与丰富的数据集资源，并提出了转录组-表型偶联的研究策略。本研究结果可为进行性纤维化性间质性肺疾病中的TGFβ研究、药物研发及生物标志物鉴定提供重要参考价值。