Hemoglobin expression in neurons and glia after intracerebral hemorrhage

The purpose of this study was to examine the expression of hemoglobin (Hb) in the brain after intracerebral hemorrhage (ICH) and the effects of hemin and iron on neuronal Hb. For the in vivo studies, male Sprague-Dawley rats received either a sham operation or an ICH. The rats were killed 1, 4, 24 or 72 h later, and brains were used for real-time polymerase chain reaction (PCR) and immunohistochemistry. For the in vitro study, primary cultured neurons were exposed to either hemin or vehicle. Some neurons also received treatment with deferoxamine, an iron chelator. Neurons were collected 24 h later for real-time PCR. We found that α-globin (HbA) and β-globin (HbB) mRNA levels in the ipsilateral basal ganglia are significantly increased after ICH, and Hb is localized in neurons and glia cells. Exposure of neurons to hemin also upregulated HbA and HbB mRNA levels. Hemin-induced HbA and HbB expression in cultured neurons was reduced by deferoxamine treatment. These results indicate that ICH increases HbA and HbB expression in neurons and glia cells, and that heme and iron may be important factors in inducing endogenous Hb expression after ICH.