From the Department of Neurological Surgery (E.W., D.W., E.G., J.R., M.B., D.L., A.A.), Department of Radiology and Biomedical Imaging (D.M., K.N., Z.S., D.C.), Center for Cerebrovascular Research (H.K., S.W.), Department of Psychiatry (T.N.), Department of Behavioral Sciences (T.N.), and Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research (T.N., D.L.), University of California San Francisco; Siemens Medical Solutions Inc (K.M.), Malvern, PA; and Department of Anatomy (J.R., T.N.), University of California San Francisco, Chan Zuckerberg Biohub.
Neurology. 2022 Apr 19;98(16):e1637-e1647. doi: 10.1212/WNL.0000000000200109. Epub 2022 Feb 10.
Ras-mitogen-activated protein kinase (MAPK) signaling abnormalities occur in most brain arteriovenous malformations (bAVMs). No means exist to molecularly profile bAVMs without open surgery, limiting precision medicine approaches to treatment. Here, we report use of endoluminal biopsy of the vessel lumen of bAVMs to characterize gene expression and blood flow-mediated transcriptional changes in living patients.
Endoluminal biopsy and computational fluid dynamic modeling (CFD) were performed in adults with unruptured AVMs with cerebral angiography. Each patient underwent surgical resection and cell sampling from a contiguous arterial segment. Fluorescence-assisted cell sorting enriched endothelial cells, which were sequenced on an Illumina HiSeq 4000 sequencer. Gene expression was quantified with RNA sequencing (RNAseq). Differential gene expression, ontology, and correlative analyses were performed. Results were validated with quantitative reverse transcription PCR (RT-qPCR).
Endoluminal biopsy was successful in 4 patients without complication. Endoluminal biopsy yielded 269.0 ± 79.9 cells per biopsy (control 309.2 ± 86.6 cells, bAVM 228.8 ± 133.4 cells). RNAseq identified 106 differentially expressed genes (DEGs) in bAVMs (false discovery rate ≤0.05). DEGs were enriched for bAVM pathogenic cascades, including Ras-MAPK signaling ( < 0.05), and confirmed with RT-qPCR and a panel predictive of MAPK/extracellular signal-regulated kinase inhibitor response. Compared to patient-matched surgically excised tissues, endoluminal biopsy detected 83.3% of genes, and genome-wide expression strongly correlated (Pearson = 0.77). Wall shear stress measured by CFD correlated with inflammatory pathway upregulation. Comparison of pre-embolization and postembolization samples confirmed flow-mediated gene expression changes.
Endoluminal biopsy allows molecular profiling of bAVMs in living patients. Gene expression profiles are similar to those of tissues acquired with open surgery and identify potentially targetable Ras-MAPK signaling abnormalities in bAVMs. Integration with CFD allows determination of flow-mediated transcriptomic alterations. Endoluminal biopsy may help facilitate trials of precision medicine approaches to bAVMs in humans.
大多数脑动静脉畸形（bAVM）存在 Ras-有丝分裂原激活蛋白激酶（MAPK）信号异常。由于缺乏不开颅手术就能对其进行分子分析的手段，限制了精准医疗方法在治疗中的应用。本研究报告了使用 bAVM 血管腔内活检来对患者的活体组织进行基因表达和血流介导的转录变化分析。
对未破裂的伴有脑血管造影的 AVM 成人患者进行血管腔内活检和计算流体动力学建模（CFD）。每位患者均接受了手术切除和取自相邻动脉节段的细胞取样。荧光辅助细胞分选富集内皮细胞，然后在 Illumina HiSeq 4000 测序仪上进行测序。采用 RNA 测序（RNAseq）定量基因表达。进行差异基因表达、本体论和相关性分析。通过定量逆转录 PCR（RT-qPCR）验证结果。
4 例患者的血管腔内活检均成功完成，且无并发症发生。腔内活检每个样本获得 269.0±79.9 个细胞（对照组 309.2±86.6 个细胞，bAVM 228.8±133.4 个细胞）。RNAseq 在 bAVM 中鉴定出 106 个差异表达基因（DEGs）（错误发现率≤0.05）。DEGs 富集了与 bAVM 发病机制相关的基因，包括 Ras-MAPK 信号通路（ < 0.05），并通过 RT-qPCR 和预测 MAPK/细胞外信号调节激酶抑制剂反应的基因进行了验证。与患者匹配的手术切除组织相比，腔内活检检测到 83.3%的基因，全基因组表达相关性较强（Pearson = 0.77）。CFD 测量的壁面剪切力与炎症途径的上调相关。栓塞前和栓塞后样本的比较证实了血流介导的基因表达变化。
血管腔内活检可对活体患者的 bAVM 进行分子分析。基因表达谱与通过开颅手术获得的组织相似，并确定了 bAVM 中潜在的可靶向 Ras-MAPK 信号异常。与 CFD 整合可确定血流介导的转录组改变。血管腔内活检可能有助于促进针对人类 bAVM 的精准医疗方法的临床试验。
