Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN.
Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN.
J Cell Biol. 2021 May 3;220(5). doi: 10.1083/jcb.202007152.
Matrix stiffness is a central regulator of fibroblast function. However, the transcriptional mechanisms linking matrix stiffness to changes in fibroblast phenotype are incompletely understood. Here, we evaluated the effect of matrix stiffness on genome-wide chromatin accessibility in freshly isolated lung fibroblasts using ATAC-seq. We found higher matrix stiffness profoundly increased global chromatin accessibility relative to lower matrix stiffness, and these alterations were in close genomic proximity to known profibrotic gene programs. Motif analysis of these regulated genomic loci identified ZNF416 as a putative mediator of fibroblast stiffness responses. Genome occupancy analysis using ChIP-seq confirmed that ZNF416 occupies a broad range of genes implicated in fibroblast activation and tissue fibrosis, with relatively little overlap in genomic occupancy with other mechanoresponsive and profibrotic transcriptional regulators. Using loss- and gain-of-function studies, we demonstrated that ZNF416 plays a critical role in fibroblast proliferation, extracellular matrix synthesis, and contractile function. Together, these observations identify ZNF416 as novel mechano-activated transcriptional regulator of fibroblast biology.
基质硬度是成纤维细胞功能的一个核心调节因子。然而，将基质硬度与成纤维细胞表型变化联系起来的转录机制还不完全清楚。在这里，我们使用 ATAC-seq 评估了基质硬度对新分离的肺成纤维细胞全基因组染色质可及性的影响。我们发现，较高的基质硬度与较低的基质硬度相比，会显著增加整体染色质的可及性，并且这些改变与已知的致纤维基因程序在基因组上紧密相邻。对这些受调控的基因组位点进行基序分析，鉴定出 ZNF416 是成纤维细胞对刚度反应的一个潜在介质。使用 ChIP-seq 进行的基因组占据分析证实，ZNF416 占据了广泛涉及成纤维细胞激活和组织纤维化的基因，与其他机械响应和致纤维转录调节因子的基因组占据重叠相对较少。通过失活和功能获得研究，我们证明了 ZNF416 在成纤维细胞增殖、细胞外基质合成和收缩功能中发挥着关键作用。总之，这些观察结果表明 ZNF416 是成纤维细胞生物学的新型机械激活转录调节因子。
