The penumbra Electron transport chain
region had increased expression of MMP-9 (Fig.?5a�Cc) at 4?h following IR. The expression of MMP-9 colocalized with CD34, an endothelial cell marker (lower panels of Fig.?5a and b) as well as NSE, a neuronal cell marker(lower panels of Fig.?5c and d). GSNO treatment prevented the increase in the expression of MMP-9. The sham-operated brain had no significant expression of MMP-9. NF-��B regulates the activity/expression of several genes, including adhesion molecules and MMP-9, implicated in BBB leakage. We previously observed the increased NF-��B activity within 4?h in IR rats (Khan et?al. 2007), and the activity of NF-��B was inhibited by the treatment with GSNO in endothelial as well as inflammatory cells (Khan et?al. 2005; Prasad et?al. 2007). GSNO was reported to reduce the activity of NF-��B by inhibiting its DNA-binding activity (Marshall and Stamler 2001).Therefore, we determined whether the increased NF-��B translocation/activity was inhibited by GSNO treatment of IR using IHC and the measurement of the activity of NF-��B/p65 binding with DNA as previously described (Khan et?al. 2007). The expression of p65 was observed in all the three groups at 4?h after Tacrolimus order
reperfusion (Fig.?6a and b). However, the expression of p65 in sham was localized in the cytosol, whereas p65 translocated and localized in the nucleus in IR and GSNO groups (Fig.?6a, lower magnified panel). To examine that the activity was decreased in spite of p65 translocation to the nucleus in the GSNO group, the activity of NF-��B was measured in the nuclear fraction. Fig.?6c shows that IR had significantly higher activity in the penumbra 4?h after reperfusion than sham. The activity of NF-��B was significantly inhibited (p?<?0.001) by GSNO treatment. Decreased NO levels <a href="http://www.selleckchem.com/products/mitomycin-c.html
">Mitomycin C chemical structure in IR, because of its conversion to peroxynitrite, are implicated in endothelial dysfunction and its consequent BBB leakage. Therefore, the activity of cNOS and eNOS and the levels of NO were determined following IR. The contribution by iNOS was not studied because its induction was not observed until 6?h after reperfusion in the MCAO rat model. cNOS activity was significantly increased in IR at 1-h reperfusion (Fig.?7a). GSNO treatment of IR inhibited this activity (Fig.?7a). NO-producing eNOS activity was low in IR compared with sham (Fig.?7b). eNOS activity was further reduced by GSNO (Fig.?7b). Levels of NO in the penumbra decreased significantly in IR compared with sham measured at 4?h following reperfusion (Fig.?7c). These results are in agreement with the previously reported reduced levels of NO in cerebral tissues following acute brain injury (Irmak et?al. 2003). Treatment with GSNO maintained the levels of NO in the penumbra (Fig.?7c). Deficient S-nitrosylation is observed in several neurodegenerative disease processes (Rauhala et?al. 1996; Ju et?al. 2005; Schonhoff et?al. 2006).