Platelet derived growth factor (PDGF)-B plays a neuroprotective role in brain damages, including ischemic stroke. It has been suggested recently that PDGF receptor β (PDGFRβ) expressed in brain pericytes as well as in neurons and astrocytes may mediate the neuroprotective role of PDGF-B. The aims of this study were to elucidate the roles of PDGFRβ signaling in brain pericytes after ischemic stroke. In a rat middle cerebral artery occlusion (MCAO) model, PDGFRβ expression was induced specifically in the pericytes in peri-infarct areas and its level was gradually increased. PDGF-B induced marked phosphorylation of Akt in cultured brain pericytes. Consistently, PDGF-B was upregulated in endothelial cells in per-infarct areas and Akt was strongly phosphorylated in the PDGFRβ-expressing pericytes in periinfarct areas after MCAO. In the cultured pericytes, PDGF-B induced cell growth and anti-apoptotic responses through Akt. Furthermore, PDGF-B significantly increased the expression of nerve growth factor (NGF) and neurotrophin-3 (NT-3) through Akt in the pericytes. Thus, the PDGFRβ-Akt signaling in brain pericytes may play various important roles leading to neuroprotection after ischemic stroke.

Abstract-The relationship between the poststroke blood pressure (BP) and functional outcomes in patients with acute ischemic stroke is still controversial. The aim of the present study was to elucidate the impact of the poststroke BP on the clinical outcomes of acute ischemic stroke. Among the patients in the Fukuoka Stroke Registry, 1874 patients with first-ever acute ischemic stroke (within 24 hours of onset) who had been functionally independent before onset were prospectively enrolled in the present study. The poststroke BP levels were defined as the average values during the 48 hours after onset. The study outcomes were a good neurological recovery, neurological deterioration, and a poor functional outcome. The higher poststroke BP levels were significantly associated with a lower probability of a good neurological recovery and elevated risks of neurological deterioration and a poor functional outcome after adjusting for potential confounding factors. The multivariate-adjusted odds ratios (95% confidence interval) in the highest quintile of systolic BP (versus the lowest quintile as a reference) were 0.51 (0.37-0.71) for a good neurological recovery, 1.92 (1.15-3.27) for neurological deterioration, and 2.51 (1.69-3.74) for a poor functional outcome. Similar associations were observed when we applied the poststroke diastolic BP or pulse pressure. No evidence of the J-curve phenomenon was observed for each association. These results suggest that a high poststroke BP was significantly associated with unfavorable clinical outcomes in patients with acute ischemic stroke. There was no evidence of the J-curve phenomenon between the poststroke BP levels and the clinical outcomes.

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BackgroundVolume isotropic turbo spin-echo acquisition (VISTA) is a new method similar to the 3D black-blood imaging method that enables visualization of a intramural hematoma. T1-VISTA has recently been applied in the diagnosis of intracranial arterial dissection. However, the identification of an intramural hematoma in posterior inferior cerebellar dissection (PICA-D) by T1-VISTA has only rarely been reported.Case presentationWe herein report two patients who suffered from PICA-D complicated with ischemic stroke. Initial magnetic resonance arteriography was not informative, however, T1-VISTA depicted high-intensity signal areas suggesting an intramural hematoma of PICA-D in both cases. The high-intensity signal areas gradually reduced and finally disappeared at 4 months and 5 months after the onset, respectively.ConclusionOur cases demonstrate that T1-VISTA was able to assist in the diagnosis and follow-up of PICA-D.