Hirofumi Nakaoka1, Atsushi Tajima1, Taku Yoneyama1, Kazuyoshi Hosomichi1, Hidetoshi Kasuya1, Tohru Mizutani1, Ituro Inoue2. 1. From the Division of Human Genetics, Department of Integrated Genetics, National Institute of Genetics, Mishima, Japan (H.N., K.H., I.I.); Department of Human Genetics, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan (A.T.); Department of Neurosurgery, Neurological Institute, Tokyo Women's Medical University, Tokyo, Japan (T.Y., H.K.); and Department of Neurosurgery, School of Medicine, Showa University, Tokyo, Japan (T.M.). 2. From the Division of Human Genetics, Department of Integrated Genetics, National Institute of Genetics, Mishima, Japan (H.N., K.H., I.I.); Department of Human Genetics, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan (A.T.); Department of Neurosurgery, Neurological Institute, Tokyo Women's Medical University, Tokyo, Japan (T.Y., H.K.); and Department of Neurosurgery, School of Medicine, Showa University, Tokyo, Japan (T.M.). itinoue@nig.ac.jp.
Abstract
BACKGROUND AND PURPOSE: The rupture of intracranial aneurysm (IA) causes subarachnoid hemorrhage associated with high morbidity and mortality. We compared gene expression profiles in aneurysmal domes between unruptured IAs and ruptured IAs (RIAs) to elucidate biological mechanisms predisposing to the rupture of IA. METHODS: We determined gene expression levels of 8 RIAs, 5 unruptured IAs, and 10 superficial temporal arteries with the Agilent microarrays. To explore biological heterogeneity of IAs, we classified the samples into subgroups showing similar gene expression patterns, using clustering methods. RESULTS: The clustering analysis identified 4 groups: superficial temporal arteries and unruptured IAs were aggregated into their own clusters, whereas RIAs segregated into 2 distinct subgroups (early and late RIAs). Comparing gene expression levels between early RIAs and unruptured IAs, we identified 430 upregulated and 617 downregulated genes in early RIAs. The upregulated genes were associated with inflammatory and immune responses and phagocytosis including S100/calgranulin genes (S100A8, S100A9, and S100A12). The downregulated genes suggest mechanical weakness of aneurysm walls. The expressions of Krüppel-like family of transcription factors (KLF2, KLF12, and KLF15), which were anti-inflammatory regulators, and CDKN2A, which was located on chromosome 9p21 that was the most consistently replicated locus in genome-wide association studies of IA, were also downregulated. CONCLUSIONS: We demonstrate that gene expression patterns of RIAs were different according to the age of patients. The results suggest that macrophage-mediated inflammation is a key biological pathway for IA rupture. The identified genes can be good candidates for molecular markers of rupture-prone IAs and therapeutic targets.
BACKGROUND AND PURPOSE: The rupture of intracranial aneurysm (IA) causes subarachnoid hemorrhage associated with high morbidity and mortality. We compared gene expression profiles in aneurysmal domes between unruptured IAs and ruptured IAs (RIAs) to elucidate biological mechanisms predisposing to the rupture of IA. METHODS: We determined gene expression levels of 8 RIAs, 5 unruptured IAs, and 10 superficial temporal arteries with the Agilent microarrays. To explore biological heterogeneity of IAs, we classified the samples into subgroups showing similar gene expression patterns, using clustering methods. RESULTS: The clustering analysis identified 4 groups: superficial temporal arteries and unruptured IAs were aggregated into their own clusters, whereas RIAs segregated into 2 distinct subgroups (early and late RIAs). Comparing gene expression levels between early RIAs and unruptured IAs, we identified 430 upregulated and 617 downregulated genes in early RIAs. The upregulated genes were associated with inflammatory and immune responses and phagocytosis including S100/calgranulin genes (S100A8, S100A9, and S100A12). The downregulated genes suggest mechanical weakness of aneurysm walls. The expressions of Krüppel-like family of transcription factors (KLF2, KLF12, and KLF15), which were anti-inflammatory regulators, and CDKN2A, which was located on chromosome 9p21 that was the most consistently replicated locus in genome-wide association studies of IA, were also downregulated. CONCLUSIONS: We demonstrate that gene expression patterns of RIAs were different according to the age of patients. The results suggest that macrophage-mediated inflammation is a key biological pathway for IA rupture. The identified genes can be good candidates for molecular markers of rupture-prone IAs and therapeutic targets.
Authors: A Rouchaud; C Johnson; E Thielen; D Schroeder; Y-H Ding; D Dai; W Brinjikji; J Cebral; D F Kallmes; R Kadirvel Journal: AJNR Am J Neuroradiol Date: 2015-12-31 Impact factor: 3.825
Authors: Daniel L Cooke; David B McCoy; Van V Halbach; Steven W Hetts; Matthew R Amans; Christopher F Dowd; Randall T Higashida; Devon Lawson; Jeffrey Nelson; Chih-Yang Wang; Helen Kim; Zena Werb; Charles McCulloch; Tomoki Hashimoto; Hua Su; Zhengda Sun Journal: Transl Stroke Res Date: 2017-09-13 Impact factor: 6.829