背景:胎盘植入谱系障碍(PAS)是一种严重的并发症,其特征是滋养细胞异常侵入子宫肌层。PAS的潜在机制涉及各种细胞类型和分子途径的复杂相互作用。尽管意义重大,这种情况的特征和复杂的机制仍然知之甚少。
方法:空间转录组学(ST)和单细胞RNA测序(scRNA-seq),对四名PAS患者的组织样本进行了检查,包括侵入性组织(ST,n=3;scRNA-seq,n=4),非侵入性正常胎盘样本(ST,n=1;scRNA-seq,n=2)。三名健康的足月孕妇提供了正常的子宫肌层样本(ST,n=1;scRNA-seq,n=2)。ST分析表征了空间表达景观,和scRNA-seq用于鉴定PAS中的特定细胞成分。进行免疫荧光染色以验证发现。
结果:ST切片明确显示PAS中的子宫肌层被三个滋养层细胞亚群侵入,绒毛外滋养层细胞,滋养细胞,和合胞体滋养层,特别是绒毛外滋养层细胞。滋养细胞中基因富集的途径,平滑肌细胞(SMC),PAS的免疫细胞主要与免疫和炎症相关。我们确定了血管生成刺激基因PTK2的表达升高,以及细胞增殖增强基因EGFR。在PAS组的滋养细胞内。滋养细胞主要促进HLA-G和EBI3信号的增强,这对建立免疫逃逸至关重要。同时,PAS中的SMC区域表现出免疫调节标志物如CD274、HAVCR2和IDO1的上调,实验证实CD274表达在PAS组的侵袭性SMC区域中增加。
结论:本研究在单细胞和空间水平上提供了PAS细胞组成和空间组织的信息。PAS中基因表达失调揭示了在PAS入侵期间,滋养细胞中增强的免疫逃逸与SMC中的免疫耐受之间的复杂相互作用。这些发现将增强我们对PAS发病机制的理解,以开发潜在的治疗策略。
BACKGROUND: Placenta accreta spectrum disorders (PAS) are a severe complication characterized by abnormal trophoblast invasion into the myometrium. The underlying mechanisms of PAS involve a complex interplay of various cell types and molecular pathways. Despite its significance, both the characteristics and intricate mechanisms of this condition remain poorly understood.
METHODS: Spatial transcriptomics (ST) and single-cell RNA sequencing (scRNA-seq), were performed on the tissue samples from four PAS patients, including invasive tissues (ST, n = 3; scRNA-seq, n = 4), non-invasive normal placenta samples (ST, n = 1; scRNA-seq, n = 2). Three healthy term pregnant women provided normal myometrium samples (ST, n = 1; scRNA-seq, n = 2). ST analysis characterized the spatial expression landscape, and scRNA-seq was used to identify specific cellular components in PAS. Immunofluorescence staining was conducted to validate the findings.
RESULTS: ST slices distinctly showed the myometrium in PAS was invaded by three subpopulations of trophoblast cells, extravillous trophoblast cells, cytotrophoblasts, and syncytiotrophoblasts, especially extravillous trophoblast cells. The pathways enriched by genes in trophoblasts, smooth muscle cells (SMC), and immune cells of PAS were mainly associated with immune and inflammation. We identified elevated expression of the angiogenesis-stimulating gene PTK2, alongside the cell proliferation-enhancing gene EGFR, within the trophoblasts of PAS group. Trophoblasts mainly contributed the enhancement of HLA-G and EBI3 signaling, which is crucial in establishing immune escape. Meanwhile, SMC regions in PAS exhibited upregulation of immunomodulatory markers such as CD274, HAVCR2, and IDO1, with CD274 expression experimentally verified to be increased in the invasive SMC areas of the PAS group.
CONCLUSIONS: This study provided information of cellular composition and spatial organization in PAS at single-cell and spatial level. The dysregulated expression of genes in PAS revealed a complex interplay between enhanced immune escape in trophoblasts and immune tolerance in SMCs during invasion in PAS. These findings will enhance our understanding of PAS pathogenesis for developing potential therapeutic strategies.