Objectives

Congenital cystic adenomatoid malformation (CCAM) is the most common congenital pulmonary anomaly with unknown etiology. Here, single-cell RNA sequencing (scRNA-seq) was used to map its cellular landscape and identify the underlying cellular and molecular events related to CCAM.

Methods

This study involved a 4.25 year old patient with grade Ⅱ–Ⅲ CCAM at the Children's Hospital of Fudan University. Samples of lesioned and non-lesioned areas were collected during surgery for scRNA-seq.

Results

In total, 19,904 cells were obtained with median UMI counts of 7032 per cell and 1995 median genes per cell. In terms of lesioned and non-lesioned areas, epithelial cells accounted for 27.23% and 17.85%, respectively, while mesenchymal cells accounted for 2.67% and 16.06%, respectively (P < 0.0001). Further clustering of epithelial cells revealed that the fractions of alveolar type 1 cells (AT1, N: 23.65%; L: 49.81%), AT2(N: 2.02%; L: 5.26%), club-1(N: 9.02%; L: 17.57%), club-3(N: 1.18%; L: 4.15%), and basal cells (N: 0.34%; L: 2.93%) were increased in lesioned samples (P < 0.0001). Pseudotime trajectory analysis showed tracks of club-1/basal cells→AT2→club-3→AT1 and club-1,2/basal→AT2. Mast cells (N: 0.63%; L: 2.48%) were also increased in lesioned samples and interactions of CD44 with HBEGF and FGFR2 were detected between mast and epithelial cells.

Conclusions

AT1, AT2, club, and basal cells were increased in CCAM patients, and newly defined club-1/3 and basal cells might be the origin of proliferating AT1 and AT2 cells. Increased mast cells might promote epithelial cell proliferation through interactions of CD44 with HBEGF and FGFR2.

中文翻译：

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单细胞转录组分析揭示了先天性囊性腺瘤样畸形中上皮细胞异常增殖的机制

目标

先天性囊性腺瘤样畸形（CCAM）是最常见的先天性肺部异常，病因不明。在这里，单细胞RNA测序（scRNA-seq）用于绘制其细胞图谱并鉴定与CCAM相关的潜在细胞和分子事件。

方法

这项研究涉及复旦大学儿童医院一名4.25岁的Ⅱ–Ⅲ级CCAM患者。在手术过程中收集病变和非病变区域的样本用于scRNA-seq。

结果

总共获得了19,904个细胞，每个细胞的UMI中位数为7032，每个细胞中位数为1995。就病变区域和非病变区域而言，上皮细胞分别占27.23％和17.85％，而间充质细胞分别占2.67％和16.06％（P <0.0001）。上皮细胞的进一步聚集显示出肺泡1型细胞的部分（AT1，N：23.65％； L：49.81％），AT2（N：2.02％； L：5.26％），club-1（N：9.02％； C：-1）。 L：患病样品中club-3（N：1.18％； L：4.15％）和基底细胞（N：0.34％； L：2.93％）增加（P <0.0001）。伪时间轨迹分析显示了club-1 /基底细胞→AT2→club-3→AT1和club-1,2 /基底→AT2的轨迹。病变样品中的肥大细胞（N：0.63％； L：2.48％）也增加，CD44与HBEGF的相互作用在肥大和上皮细胞之间检测到了FGFR2和FGFR2。

结论

CCAM患者的AT1，AT2，club和基底细胞增加，新定义的club-1 / 3和基底细胞可能是AT1和AT2细胞增殖的起源。肥大细胞增加可能通过CD44与HBEGF和FGFR2相互作用促进上皮细胞增殖。