Endovascular Biopsy of Vertebrobasilar Aneurysm in Patient With Polyarteritis Nodosa.

Kazim H Narsinh,Christopher F Dowd,Adib A Abla,Randall T Higashida,Cathra Halabi,Steven W Hetts,Karl Meisel,Matthew R Amans,Tomasz J Nowakowski,Daniel L Cooke,David B Mccoy,Ethan A Winkler,Kamileh Narsinh,Zhengda Sun,Tarik Tihan,Krishna Chaganti,Van V Halbach

doi:10.3389/fneur.2021.697105

Abstract

Background and Purpose: The management of unruptured intracranial aneurysms remains controversial. The decisions to treat are heavily informed by estimated risk of bleeding. However, these estimates are imprecise, and better methods for stratifying the risk or tailoring treatment strategy are badly needed. Here, we demonstrate an initial proof-of-principle concept for endovascular biopsy to identify the key molecular pathways and gene expression changes associated with aneurysm formation. We couple this technique with single cell RNA sequencing (scRNAseq) to develop a roadmap of the pathogenic changes of a dolichoectatic vertebrobasilar aneurysm in a patient with polyarteritis nodosa.Methods: Endovascular biopsy and fluorescence activated cell sorting was used to isolate the viable endothelial cells (ECs) using the established techniques. A single cell RNA sequencing (scRNAseq) was then performed on 24 aneurysmal ECs and 23 patient-matched non-aneurysmal ECs. An integrated panel of bioinformatic tools was applied to determine the differential gene expression, enriched signaling pathways, and cell subpopulations hypothesized to drive disease pathogenesis.Results: We identify a subset of 7 (29%) aneurysm-specific ECs with a distinct gene expression signature not found in the patient-matched control ECs. A gene set enrichment analysis identified these ECs to have increased the expression of genes regulating the leukocyte-endothelial cell adhesion, major histocompatibility complex (MHC) class I, T cell receptor recycling, tumor necrosis factor alpha (TNFα) response, and interferon gamma signaling. A histopathologic analysis of a different intracranial aneurysm that was later resected yielded a diagnosis of polyarteritis nodosa and positive staining for TNFα.Conclusions: We demonstrate feasibility of applying scRNAseq to the endovascular biopsy samples and identify a subpopulation of ECs associated with cerebral aneurysm in polyarteritis nodosa. Endovascular biopsy may be a safe method for deriving insight into the disease pathogenesis and tailoring the personalized treatment approaches to intracranial aneurysms.

Highlights

Intracranial aneurysms are a common cause of hemorrhagic stroke, resulting in severe morbidity and mortality worldwide [1]
A 56-year-old woman with an enlarging, partially thrombosed, vertebrobasilar aneurysm (Figure 1) underwent endovascular biopsy followed by flow-diversion
differentially expressed gene (DEG) in endothelial cells (ECs) Isolated From Vertebrobasilar Aneurysm vs. Peripheral Femoral Artery

Summary

Introduction

Intracranial aneurysms are a common cause of hemorrhagic stroke, resulting in severe morbidity and mortality worldwide [1]. The precision medicine approaches to intracranial aneurysms are limited by a dearth of aneurysmal tissue, whose analysis may provide insight into the molecular pathways underlying pathogenesis [8,9,10]. The aneurysm tissue obtained, when subjected to bulk immunohistochemical, transcriptomic, or proteomic analysis, the yields coarse information that may belie the contribution of rarer cell types to disease pathogenesis. We demonstrate an initial proof-of-principle concept for endovascular biopsy to identify the key molecular pathways and gene expression changes associated with aneurysm formation. We couple this technique with single cell RNA sequencing (scRNAseq) to develop a roadmap of the pathogenic changes of a dolichoectatic vertebrobasilar aneurysm in a patient with polyarteritis nodosa

Methods

Results

Conclusion