Is there any intra-aneuvrysmal blood marker of aneuvrysm wall inflammation? Crossed analysis between transcriptomic and proteomic data

Background and purpose Intracranial aneurysmformation, growth and rupture are incompletely understood. Inflammation plays a key role in the formation and rupture of intracranial aneurysms. Inflammation is mediated through several factors such as cytokines, chemokines and growth factors. The purpose of this study was to determine if these inflammatory proteins were increased in the lumen of human intracranial aneurysmand correlate these data with gene expression regulation ( transcriptomic) at tissue level. Methods The concentration of 27 inflammatory proteins in blood samples drawn from the lumen of human intracranial unruptured aneurysmsof 21 patients were compared with blood samples from the femoral arteriesof the same patients. We compared these proteomic data from intra- aneurysmalblood with transcriptomicdata obtained by RNA sequencing of 7 human unruptured aneurysmwalls and 6 human controls cortical arteries. Results The mean serum concentration of Il-1ra, IL-2, IL-5, IL-6 FGF-basic, GM-CSF, MCP-1, TNF-I± and MIP-1I± was significantly higher in samples taken from cerebral aneurysmscompared to femoral arteries. In our transcriptomicanalysis, we found a significant upregulation of IL-2 gene and IL-5 gene (coding for IL-2 and IL-5) in aneurysmwalls compared with controls cortical arteries. Conclusion Higher concentration of inflammatory proteins was found in intra- aneurysmalsampling compared with femoral sampling. Transcriptomicdata showed an upregulation of IL-2 gene and IL-5 gene in aneurysmwalls compared with controls cortical arteries. Our findings suggest that we may detect intra- aneurysmalblood marker of aneurysmwall inflammation.