Single cell RNA sequencing analysis of vestibular schwannoma reveals functionally distinct macrophage subsets

Background: Vestibular schwannomas (VS) remain a challenge due to their anatomical location and propensity to growth. Macrophages are present in VS but their roles in VS pathogenesis remains unknown. Objectives: Assess phenotypic and functional profile of macrophages in VS with single cell RNA sequencing (scRNAseq). Methods: scRNAseq was carried out in three VS samples to examine characteristics of macrophages in the tumor. RT-qPCR was carried out on ten VS samples for CD14, CD68 and CD163 and a panel of macrophage associated molecules. Results: scRNAseq revealed macrophages to be a major constituent of VS microenvironment with three distinct subclusters based on gene expression. The subclusters were also defined by expression of CD163, CD68 and IL-1β. AREG and PLAUR were expressed in the CD68+CD163+IL-1β+ subcluster, PLCG2 and NCKAP5 were expressed in CD68+CD163+IL-1β- subcluster and AUTS2 and SPP1 were expressed in the CD68+CD163-IL-1β+ subcluster. RT-qPCR showed expression of several macrophage markers in VS of which CD14, ALOX15, Interleukin-1β, INHBA and Colony Stimulating Factor-1R were found to have a high correlation with tumor volume. Conclusions: Macrophages form an important component of VS stroma. scRNAseq reveals three distinct subsets of macrophages in the VS tissue which may have differing roles in the pathogenesis of VS. single cell RNA sequencing analysis of vestibular schwannoma

背景：前庭神经鞘瘤（vestibular schwannomas，VS）因独特的解剖位置及生长特性，始终是临床诊疗与基础研究中的难点。巨噬细胞已被证实存在于VS组织中，但其在VS发病机制中的具体作用仍未明确。研究目标：本研究拟通过单细胞RNA测序（single cell RNA sequencing，scRNAseq）分析VS中巨噬细胞的表型与功能特征。研究方法：本研究对3例VS样本实施单细胞RNA测序，以解析肿瘤组织内巨噬细胞的特征；同时对10例VS样本进行逆转录定量PCR（RT-qPCR），检测CD14、CD68、CD163及一系列巨噬细胞相关分子的表达水平。研究结果：单细胞RNA测序结果显示，巨噬细胞是VS肿瘤微环境的主要组成成分，基于基因表达模式可将其分为3个截然不同的亚群。这3个亚群亦可通过CD163、CD68及白细胞介素-1β（IL-1β）的表达特征进行界定：CD68+CD163+IL-1β+亚群表达AREG与PLAUR，CD68+CD163+IL-1β-亚群表达PLCG2与NCKAP5，CD68+CD163-IL-1β+亚群则表达AUTS2与SPP1。逆转录定量PCR结果显示，VS组织中存在多种巨噬细胞标志物的表达，其中CD14、ALOX15、IL-1β、INHBA及集落刺激因子1受体（Colony Stimulating Factor-1R）的表达水平与肿瘤体积呈显著相关性。研究结论：巨噬细胞是VS肿瘤间质的重要组成成分；单细胞RNA测序揭示了VS组织内巨噬细胞存在3种独特亚群，这些亚群可能在VS的发病机制中发挥不同的作用。本数据集为前庭神经鞘瘤的单细胞RNA测序分析数据集。