Role of the X-chromosome in Pulmonary Arterial Hypertension

项目摘要 摘要肺动脉高压(PAH)是一种以增生性改变为特征的严重肺部疾病。 在导致血管狭窄的小肺动脉中，肺动脉压力升高和 右心衰竭。越来越多的证据表明，PAH患者肺部的增生性病变是 类似于肿瘤，具有单克隆性扩张和遗传不稳定性。为了支持这一点，我们最近 在PAH肺内皮细胞中发现染色体异常，包括嵌合体缺失 16%的女性患者有X染色体。我们还发现了令人惊讶的高频率(32%) 非常扭曲的X-失活模式，这可能代表单克隆性或重新激活 不活跃的X染色体。在这项研究中，我们将对小学X-失活进行详细的分析 细胞培养和未培养的肺组织来区分这两个假说，并确定 X染色体缺失的病例失去了活跃或非活跃的X等位基因的表达。 连接的基因将使用下一代测序和原位杂交进行分析 用于可视化X染色体拷贝数和XIST表达，X-失活的标志 未培养的组织切片。单克隆性频率的确定对瘤样病变至关重要 PAH的发病模型和X染色体的其他异常可以部分解释 女性的发病率高于男性。

Project Summary Pulmonary arterial hypertension (PAH) is a serious lung disease characterized by proliferative changes in the small pulmonary arteries that leads to vessel narrowing, elevated pulmonary artery pressure and right heart failure. There is growing evidence that proliferative lesions in the lungs of PAH patients are akin to neoplasia, with monoclonal expansion and genetic instability. Supporting this, we recently identified chromosomal abnormalities in endothelial cells from PAH lungs, including mosaic deletions of the X-chromosome in 16% of female cases. We have also found a surprisingly high frequency (32%) of very skewed X-inactivation patterns, which may represent monoclonality or reactivation of the inactive X-chromosome. In this study we will conduct a detailed analysis of X-inactivation in primary cell cultures and uncultured lung tissue to distinguish these two hypotheses and also identify whether cases with X-chromosome deletion have lost the active or inactive X. Allele-specific expression of X- linked genes will be analyzed using next generation sequencing and in situ hybridization will be performed to visualize X-chromosome copy number and XIST expression, a marker of X-inactivation, in uncultured tissue sections. Determining the frequency of monoclonality is critical to the neoplasia-like model for PAH pathogenesis and other abnormalities of the X-chromosome may in part explain the higher incidence in females than males.