ABSTRACT
<p><b>OBJECTIVE</b>To study biological effect of recombinant human erythropoietin (RhEPO) on the expression of oligodendrocyte in the neuron glia antigen 2(NG2), Nogo receptor-interacting protein 1(LINGO-1), myelin basic protein (MBP) and myelin associated glycoprotein (MAG), and to explore the protective mechanism of RhEPO for oligodendrocyte after cerebral infarction.</p><p><b>METHODS</b>Experimental rats were randomly divided into the treatment group (RhEPO at a dose of 3 000 U/kg) or saline control group. Both groups received intraperitoneal injection of RhEPO after cerebral ischemia in 30 min, 3 h, 6 h, 12 h and 24 h, which was administered daily for 7 days. The modified neurological severity score (mNSS) and histology were analyzed, and immunohistochemistry was used to detect the protein expression of NG2, MAG, MBP and LINGO-1.</p><p><b>RESULTS</b>The overall mNSS of RhEPO treatment group significantly decreased compared with the saline control group on the seventh day after cerebral infarction (P<0.05). Such treatment effect was more obvious in the treatment group at 30 min and 3 h (P<0.01). Compared with the saline control group, the numbers of NG2 positive cells increased in RhEPO treatment group. In contrast, the expression of LINGO-1 protein significantly decreased (P<0.05), with a dramatic decrease observed at 30 min and 3 h (P<0.01). However, the expression of MBP protein decreased more significantly in saline control group, while the level of the MAG protein expression increased. The differences were statistically significant (P<0.05), especially at 30 min (P<0.01).</p><p><b>CONCLUSIONS</b>After cerebral ischemia, RhEPO promotes the proliferation of NG2 positive cells, and inhibits the expression of LINGO-1 and MAG proteins. RhEPO improves the proliferation and differentiation of oligodendrocyte precursor cells, which in turn protects neuronal function, particularly at the early phase of ischemia.</p>
ABSTRACT
Objective To investigate the relevance between protein expression and methylation of MG-MT and hMSH2 in glioma patimts.Methods Immunohistochemical and methylation specific PCR were adopted respectively to test on 275 cases of glioma patients for the protein expression and methylation situation of MGMT and hMSH2.Results The negative protein expression rate of MGMT and hMSH 2 in the tissue of brain golima were 47.2% and 62.5% respectively;the occurrence of methylation in gene promoter region were accordingly 41.8% and 22.4%.Statistical analysis revealed that MGMT promoter methylation in peripheral blood gene groups was related with the protein negative expression of tumor tissue (P0.05).Conclusion The meth-ylation of MGMT is a common molecular situation in the generation of brain glioma ,which may be connected with that of tumor.However,hMSH2 promoter methylation might not the main reason for inactivation of hMSH 2 pro-tein,there may be other important factors affecting its expression .