Genome-wide maps of chromatin openness in control and LMNA R527C mutant MSCs

We performed ATAC-seq to examine to chromatin of openness of coding genes in healthy control and LMNA R527C patient-derived MSCs. The reduction of LADs did not increase the accessibility of the promoters flanking coding genes. The genome wide analysis of ATAC-seq showed that openness of coding genes related chromatin was decreased in mutant MSCs.Thus, R527C mutant Lamin A led to dysfunction of LADs and dysregulation of gene transcription, probably, leading to slow down or arrest of cell proliferation and differentiation. Overall design: LADs were distributed across heterochromatic, promoter, and actively transcribed regions of the genome and were associated with DNA methylation and suppressed gene expression. We thus performed ATAC-seq to examine to chromatin of openness of coding genes in control and LMNA R527C mutant MSCs as Lamin A-LADS binding affinity were changed during LMNA R527C mutation. Examination of chromatin openness in control and LMNA R527C mutant MSCs.

我们采用转座酶可及性测序（ATAC-seq），检测健康对照组及LMNA R527C突变患者来源的间充质干细胞（Mesenchymal Stem Cells, MSCs）中编码基因的染色质可及性。核纤层相关结构域（Lamina-Associated Domains, LADs）的减少并未提升侧翼编码基因启动子的可及性。全基因组ATAC-seq分析显示，突变型MSCs中与编码基因相关的染色质可及性出现降低。综上，R527C突变型核纤层蛋白A（Lamin A）可导致LADs功能异常与基因转录失调，或进而引发细胞增殖与分化速率减缓乃至停滞。
实验整体设计：LADs广泛分布于基因组的异染色质、启动子及活跃转录区域，且与DNA甲基化及基因表达抑制存在关联。鉴于LMNA R527C突变会改变核纤层蛋白A与LADs的结合亲和力，我们遂通过ATAC-seq检测对照组与LMNA R527C突变型MSCs中编码基因的染色质可及性。对对照组及LMNA R527C突变型MSCs的染色质可及性进行检测。