Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, USA.
Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
Genome Biol. 2018 Oct 25;19(1):176. doi: 10.1186/s13059-018-1551-9.
In response to a wound, fibroblasts are activated to migrate toward the wound, to proliferate and to contribute to the wound healing process. We hypothesize that changes in pre-mRNA processing occurring as fibroblasts enter the proliferative cell cycle are also important for promoting their migration.
RNA sequencing of fibroblasts induced into quiescence by contact inhibition reveals downregulation of genes involved in mRNA processing, including splicing and cleavage and polyadenylation factors. These genes also show differential exon use, especially increased intron retention in quiescent fibroblasts compared to proliferating fibroblasts. Mapping the 3' ends of transcripts reveals that longer transcripts from distal polyadenylation sites are more prevalent in quiescent fibroblasts and are associated with increased expression and transcript stabilization based on genome-wide transcript decay analysis. Analysis of dermal excisional wounds in mice reveals that proliferating cells adjacent to wounds express higher levels of cleavage and polyadenylation factors than quiescent fibroblasts in unwounded skin. Quiescent fibroblasts contain reduced levels of the cleavage and polyadenylation factor CstF-64. CstF-64 knockdown recapitulates changes in isoform selection and gene expression associated with quiescence, and results in slower migration.
Our findings support cleavage and polyadenylation factors as a link between cellular proliferation state and migration.
在应对伤口时，成纤维细胞被激活向伤口迁移、增殖，并有助于伤口愈合过程。我们假设，成纤维细胞进入增殖细胞周期时发生的前体 mRNA 加工变化对于促进其迁移也很重要。
通过接触抑制诱导静止的成纤维细胞进行 RNA 测序，揭示了参与 mRNA 加工的基因下调，包括剪接和切割及多聚腺苷酸化因子。与增殖成纤维细胞相比，这些基因在静止成纤维细胞中也表现出不同的外显子使用，特别是内含子保留增加。转录本 3' 端的映射表明，来自远端多聚腺苷酸化位点的更长转录本在静止成纤维细胞中更为普遍，并与基于全基因组转录物衰减分析的更高表达和转录物稳定性相关。对小鼠皮肤切除伤口的分析表明，与未受伤皮肤中的静止成纤维细胞相比，伤口附近的增殖细胞表达更高水平的切割和多聚腺苷酸化因子。静止成纤维细胞中切割和多聚腺苷酸化因子 CstF-64 的水平降低。CstF-64 敲低再现了与静止相关的异构体选择和基因表达变化，并导致迁移速度减慢。
我们的发现支持切割和多聚腺苷酸化因子作为细胞增殖状态和迁移之间的联系。
