Background: High mobility group box 1 (HMGB1) is a chromatin structural protein expressed ubiquitously in the nuclei of mammalian cells. Increasing evidence suggests that inflammatory responses are involved in the progression of systemic injuries induced by a diverse range of insults, including stroke, trauma, tumors, and degenerative diseases. Whether HMGB1 expression in systemic organs is associated with transient ischemic attack (TIA) remains unclear. We hypothesized that HMGB1 expression after TIA would exacerbate systemic symptoms due to acute inflammation.Material and Methods: We performed transient bilateral and unilateral common carotid artery occlusion (2VO and 1VO) on Sprague-Dawley (SD) male rats. Rats were randomized to the sham, 1VO, and 2VO groups. The sham group underwent no procedure that involved common carotid artery occlusion. Common carotid arteries were clamped for 30 minutes and, subsequently, reperfused for 24 hours. Brain, heart, liver, lung, spleen, kidney and intestine tissue samples were collected for biochemical and histopathological analysis. Protein and mRNA expression were determined by western blot analysis and polymerase chain reaction (PCR).Results: HMGB1 expression increased in the brain, liver, spleen and intestine of the rat 1VO and 2VO models. In vivo results indicated high expression of HMGB1 in TIA, and the expression of MMP-9 and PKCδ in the cerebral cortex and hippocampus was regulated by HMGB1. In the 2VO model, the expression of CD11b and GFAP in the cerebral cortex was significantly increased compared with that in the control group (P < 0.001). HMGB1 was translocated from the nucleus to the cytoplasm at early stages after TIA and then localized to the cytoplasm of phagocytic microglia at later stages.Conclusion: HMGB1 expression increased in the systemic organs after TIA. HMGB1 promotes systemic inflammation, which mediates the immune response and tissue damage in the brain after TIA. Targeting HMGB1 signaling may be a promising therapeutic approach for the treatment of TIA.

Background Patients with neurofibromatosis type 1 (NF1) have various vascular disease due to the vascular fragility, but any reports of the case of giant thrombotic aneurysm was found. We treated a rare case of giant thrombotic aneurysm of the internal carotid artery in a patient with NF1. Case presentation A 60-year-old man had suffered deteriorating visual loss and homonymous hemianopia. Contrast-enhanced computed tomography (CT) showed a giant thrombosed aneurysm on the anterior wall of the internal carotid artery (ICA) located in the optic chiasma. We planned and completed the external carotid artery-middle cerebral artery high-flow bypass using radial artery graft. The visual fields test was performed 14 days after surgery. Homonymous hemianopia persisted but no exacerbation of visual field impairment was observed. No complications were found at 14 days after surgery and the postoperative course was uneventful. Conclusions We consider that external carotid artery-middle cerebral artery bypass surgery using radial artery grafts is a safe and effective treatment method for giant thrombotic aneurysm associated with NF1.