Article Figures & Data
Figures
- Figure 1
Intraventricular injection of haemoglobin caused ventricular dilation. T2-weighted MRI and frozen coronal brain sections (A) and the measurement of ventricular volume with T2-weighted MRI (B) from mice 24 h after injection of 20 µL of saline or haemoglobin (25 mg/mL) into the right lateral ventricle. The data points represent means±SD, n=6–8, **p<0.01 versus saline group.
- Figure 2
Lipocalin 2 (LCN2) protein was markedly upregulated in the brain 24 h after intraventricular haemoglobin injection compared with saline controls. Immunohistochemistry staining demonstrated that LCN2 immunoreactivity was expressed in the periventricular area and cortex 24 h after intraventricular haemoglobin injection (A) compared with saline controls (B). Boxes show areas examined at higher magnification in the higher power micrographs on the right (scale bars=100 and 20 µm). LCN2 protein levels were upregulated in the periventricular area (C) and cortex (D) 24 h after intraventricular haemoglobin injection, as shown by western blot. The data points represent means±SD, n=3–5, **p<0.01 versus saline group.
- Figure 3
Immunoreactivity for lipocalin 2 (LCN2), glial fibrillary acidic protein (GFAP), Iba-1 and neuronal nuclei (NeuN) 24 h after intraventricular haemoglobin injection. Immunofluorescent double labelling showed that LCN2-positive cells were mainly astrocytes. Scale bar=50 µm.
- Figure 4
Immunoreactivity for the lipocalin 2 (LCN2) receptor (SLC22A17), glial fibrillary acidic protein (GFAP), Iba-1 and neuronal nuclei (NeuN) 24 h after intraventricular haemoglobin injection. Co-localisation of the LCN2 receptor with GFAP, Iba-1 and NeuN by double labelling is shown. Scale bar=50 µm.
- Figure 5
Ventricular volumes were measured before and after (24 h) the injection of haemoglobin (25 mg/mL) or saline into wild-type (WT) and in lipocalin 2-deficient (LCN2−/−) mice. Ventricular dilation was calculated as a per cent of presurgery values. Haemoglobin caused marked ventricular dilation in WT mice compared with saline controls, but not LCN2−/− mice. The data represent means±SD, n=5 for each, **p<0.01 versus WT saline group, ##p<0.01 versus LCN2−/− haemoglobin group.
- Figure 6
In wild-type (WT) mice, intraventricular injection of haemoglobin (25 mg/mL) resulted in periventricular activation of astrocytes (glial fibrillary acidic protein (GFAP) staining) and microglia (amoeboid Iba-1 staining) at 24 h compared with saline-injected controls (A). The activation by haemoglobin was attenuated in lipocalin 2-deficient (LCN2−/−) mice (A). The numbers of periventricular cells expressing GFAP (B) and Iba-1 (C) were counted in the WT and LCN2−/− mice. The data points represent the mean±SD, scale bar=50 µm, n=5 per group; **p<0.01 versus WT saline group, ##p<0.01 versus LCN2−/− haemoglobin group.
