Transcriptomic profiling across the nonalcoholic fatty liver disease spectrum reveals gene signatures for steatohepatitis and fibrosis
Transcriptomic profiling across the nonalcoholic fatty liver disease spectrum reveals gene signatures for steatohepatitis and fibrosis
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DOI：
10.1126/scitranslmed.aba4448
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发表时间：
2020-12-02
影响因子：
17.1
通讯作者：
Anstee, Quentin M.
中科院分区：
文献类型：
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作者：
Govaere, Olivier;Cockell, Simon;Anstee, Quentin M.
驱动非酒精性脂肪性肝病（NAFLD）的机制仍不完全清楚。这项大型多中心研究描述了NAFLD在病程发展为肝硬化时肝组织中发生的转录变化，以确定潜在的循环标志物。我们对来自206例NAFLD患者的组织学特征样本进行了高通量RNA测序。根据疾病活动性和纤维化分期、年龄、天冬氨酸转氨酶（AST）、2型糖尿病和携带PNPLA3 rs738409（一种与NAFLD相关的遗传变异）的差异对NAFLD进行无监督聚类分层。相对于疾病早期，我们一致鉴定出在纤维化性脂肪性肝炎进展至F2至F4阶段时25个差异表达基因。在一个单独的复制队列（n = 175）中，通过logistic模型独立验证了这一25个基因的特征，并与公开可用的单细胞RNA测序数据进行了综合分析，阐明了特定肝内细胞群可能的相对贡献。将这些发现转化为蛋白质水平，SomaScan分析了300多个NAFLD血清样本，证实了蛋白质AKR1B10和GDF15的循环浓度与疾病活度和纤维化阶段密切相关。体外功能研究支持这些数据的生物学合理性，确定内质网应激上调AKR1B10、GDF15和PDGFA的表达，而GDF15补充调节了巨噬细胞在脂质负荷和脂多糖刺激下的炎症反应。这项研究为进行性纤维化性脂肪性肝炎的病理生理学提供了见解，并证明了转录组学变化代表疾病进展的潜在可处理和临床相关标记的原理。
The mechanisms that drive nonalcoholic fatty liver disease (NAFLD) remain incompletely understood. This large multicenter study characterized the transcriptional changes that occur in liver tissue across the NAFLD spectrum as disease progresses to cirrhosis to identify potential circulating markers. We performed high-throughput RNA sequencing on a discovery cohort comprising histologically characterized NAFLD samples from 206 patients. Unsupervised clustering stratified NAFLD on the basis of disease activity and fibrosis stage with differences in age, aspartate aminotransferase (AST), type 2 diabetes mellitus, and carriage of PNPLA3 rs738409, a genetic variant associated with NAFLD. Relative to early disease, we consistently identified 25 differentially expressed genes as fibrosing steatohepatitis progressed through stages F2 to F4. This 25-gene signature was independently validated by logistic modeling in a separate replication cohort (n = 175), and an integrative analysis with publicly available single-cell RNA sequencing data elucidated the likely relative contribution of specific intrahepatic cell populations. Translating these findings to the protein level, SomaScan analysis in more than 300 NAFLD serum samples confirmed that circulating concentrations of proteins AKR1B10 and GDF15 were strongly associated with disease activity and fibrosis stage. Supporting the biological plausibility of these data, in vitro functional studies determined that endoplasmic reticulum stress up-regulated expression of AKR1B10, GDF15, and PDGFA, whereas GDF15 supplementation tempered the inflammatory response in macrophages upon lipid loading and lipopolysaccharide stimulation. This study provides insights into the pathophysiology of progressive fibrosing steatohepatitis, and proof of principle that transcriptomic changes represent potentially tractable and clinically relevant markers of disease progression.