Kim Adam, McMullen Megan R, Bellar Annette, Streem David, Dasarathy Jaividhya, Welch Nicole, Dasarathy Srinivasan
bioRxiv. 2024 Aug 9:2024.08.07.607014. doi: 10.1101/2024.08.07.607014.
Many inflammatory genes in the immune system are clustered in the genome. The 3D genome architecture of these clustered genes likely plays a critical role in their regulation and alterations to this structure may contribute to diseases where inflammation is poorly controlled. Alcohol-associated hepatitis (AH) is a severe inflammatory disease that contributes significantly to morbidity in alcohol associated liver disease. Monocytes in AH are hyper-responsive to inflammatory stimuli and contribute significantly to inflammation. We performed high throughput chromatin conformation capture (Hi-C) technology on monocytes isolated from 4 AH patients and 4 healthy controls to better understand how genome structure is altered in AH. Most chromosomes from AH and healthy controls were significantly dissimilar from each other. Comparing AH to HC, many regions of the genome contained significant changes in contact frequency. While there were alterations throughout the genome, there were a number of hotspots containing a higher density of changes in structure. A few of these hotspots contained genes involved in innate immunity including the NK-gene receptor complex and the CXC-chemokines. Finally, we compare these results to scRNA-seq data from patients with AH challenged with LPS to predict how chromatin conformation impacts transcription of clustered immune genes. Together, these results reveal changes in the chromatin structure of monocytes from AH patients that perturb expression of highly clustered proinflammatory genes.
免疫系统中的许多炎症基因在基因组中呈簇状分布。这些簇状基因的三维基因组结构可能在其调控中起关键作用,而这种结构的改变可能导致炎症控制不佳的疾病。酒精性肝炎(AH)是一种严重的炎症性疾病,在酒精性肝病的发病中起重要作用。AH中的单核细胞对炎症刺激反应过度,并在炎症中起重要作用。我们对从4例AH患者和4例健康对照中分离出的单核细胞进行了高通量染色质构象捕获(Hi-C)技术,以更好地了解AH中基因组结构是如何改变的。AH和健康对照的大多数染色体彼此之间存在显著差异。将AH与HC进行比较,基因组的许多区域在接触频率上有显著变化。虽然整个基因组都有改变,但有许多热点区域结构变化密度更高。其中一些热点区域包含参与先天免疫的基因,包括NK基因受体复合体和CXC趋化因子。最后,我们将这些结果与来自用LPS刺激的AH患者的scRNA-seq数据进行比较,以预测染色质构象如何影响簇状免疫基因的转录。总之,这些结果揭示了AH患者单核细胞染色质结构的变化,这些变化扰乱了高度簇状的促炎基因的表达。