Study On The Effects Of NE On Ischemic Injury In Cultured Neurons

Objective Ischemic cerebrovascular disease is a common disease for older persons, and it is also a major disease which leads to death and disability for the elderly. With the old population increasing in the world, the incidence rate of ischemic cerebrovascular disease is increasing gradually. Because its pathogenesis is very complex and its etiology is unknown, there hasn't been a drug which can treat it thoroughly or reverse its course for the time. In recent years, inflammation has played an important role in brain ischemia-reperfusion damage, attracting people's attention. Abundant evidence exists that an inflammatory reaction, in response to brain ischemic damage, involves infiltration of neutrophils into the injured brain parenchyma. Activated polymorphonuclear leukocytes (PMNs) can contribute to brain ischemia-reperfusion damage by mechanical obstruction and release of neutrophil elastase (NE).Sivelestat Sodium is a specific NE inhibitor, clinical studies indicate that Siv can contribute to protection for tissues suffering from ischemia- reperfusion damage by inhibiting NE, reducing neutrophils aggregation, protecting endothelial cells, improving energy metabolism, and resisting lipid oxidation. So far, there haven't been reports about the function of NE in central nervous system diseases.The topic is aim to study whether Siv can protect the neurons against PMNs, the neurons suffering from ischemia-reperfusion damage against PMNs in vitro, and its effect factors related, so as to find a new potent agent for ischemic cerebrovascular disease and other neurodegeneration diseases.Methods (1)In vitro: primary neurons were cultured using newborn rat brains, the MTT and the activity of LDH were assayed , and the pathology was observed, so as to study whether Siv can protect the neurons against PMNs and protect the neurons suffering from ischemia-reperfusion damage against PMNs.(2)Furthermore, the content of MDA and Glu, the activity of SOD, the concentration of NE and intracellular free calcium, the expression of p-p38MAPK, and the apoptosis were assayed so as to study the damage factors related to NE and the protection factors related to Siv.Results and conclusion(1) Siv(10-8mol/L,10-7mol/L,and 10-6mol/L) could increase the survival rate of the normal neurons and the neurons suffering from ischemia-reperfusion accompanied by PMNs, diminish their release of LDH and improve their pathological morphology, these effects were significantly different from those of models, in a dose dependent manner. It is suggested that Siv(10-8mol/L,10-7mol/L, and 10-6mol/L)can protect remarkably the normal neurons against PMNs and the neurons suffering from ischemia-reperfusion damage against PMNs.(2) The content of MDA and Glu,the concentration of NE and intracellular free calcium, and the expression of p-p38MAPK and bax of the normal neurons and the neurons suffering from ischemia-reperfusion damage in coculture with PMNs were increased, but their activity of SOD and the expression of bcl-2 were decreased. Siv(10-7mol/L, 10-6mol/L)could decrease the content of MDA and Glu,the concentration of NE and intracellular free calcium, and the expression of p-p38MAPK and bax, increase their activity of SOD and the expression of bcl-2, these differences were significant compared to those of models. These data suggest that the damage of NE and the protection of Siv(10-7mol/L, 10-6mol/L)are related to these factors.