Figure 5

TNF-α inhibition protected against lipopolysaccharide (LPS)-sensitized hypoxic-ischemic (HI) brain injury. (A) Etanercept at a dosage of 15 mg/kg (n = 16), but not 5 mg/kg (n = 12), significantly attenuated cortical injury (Nissl staining, upper panel), preserved myelination (MBP, middle panel), and reduced astrogliosis (GFAP, lower panel) compared to the vehicle-treated group (n = 14) after LPS-sensitized HI on P17. (B) The LPS + HI groups (n = 8) had significantly increased immunoreactivity of TNFR1 but not TNFR2 in the cortex (upper panel) and white matter (lower panel) 24 hours post-insult compared to the control groups (n = 6). The up-regulated TNFR1 was expressed in blood vessels (arrows) and non-vascular cells. Scale bar = 200 μm for MBP and 100 μm for others. Values are means ± SEM. ***P < 0.001, **P < 0.01, *P < 0.05. GFAP, glial fibrillary acidic protein; MBP, myelin basic protein; TNFR, tumor necrosis factor receptor.