Acanthopanax Senticosus Saponins induced tolerance to ischemia and its possible molecular mechanism in PC12 cells / 中华儿科杂志

ABSTRACT

<p><b>OBJECTIVE</b>To study the tolerance to ischemia induced by Acanthopanax Senticosus Saponins (ASE) in PC12 cells and the involved mechanism.</p><p><b>METHODS</b>An ischemic model was developed in PC12 cell line by treatment with oxygen-glucose deprivation. The effects of ASE pretreatment on tolerance of PC12 cells to ischemia were evaluated by MTT assay and analysis of cellular morphology. The expression of hypoxia-inducing factor (HIF)-1alpha, erythropoietin (EPO) after the pretreatment with ASE was detected by Western blotting. The DNA binding activities of HIF-1 in PC12 cells with the pretreatment of ASE were demonstrated by using electrophoretic mobility shift assay (EMSA).</p><p><b>RESULTS</b>In ischemia model, the viability of PC12 cells was decreased to (49.12 +/- 3.22)% after oxygen-glucose deprivation for 9 hours. However, ASE (50 microg/ml) pretreatment could remarkably increase the viability of PC12 cells by (67.97 +/- 2.92)%. There were significant differences between the experimental group and control group (F = 473.67, P < 0.01). The cellular morphology showed that PC12 cells exposed for 7 days to nerve growth factor (NGF) exhibited round, smooth cell bodies with normal processes and that processes formed extensive network. At 9 hour after ischemia, cell bodies of many PC12 cells were found shrinken, the processes were disrupted and network disappeared. However, pretreatment with ASE (50 microg/ml) could largely prevent the morphological damage to PC12 cells that would have caused by subsequent exposure to 9 h ischemic insult, many cellular bodies were intact and many processes and network of PC12 cells still existed. The expression of HIF-1alpha increased after pretreatment with ASE shown by Western blot. There were significant differences between the experimental group and control group (F = 167.18, P < 0.01). The DNA binding activities of HIF-1 in PC12 cells after pretreatment with ASE was significantly increased, and it could activate the expression of EPO (F = 128.37, P < 0.01).</p><p><b>CONCLUSIONS</b>The pretreatment with ASE could induce tolerance against ischemia in PC12 cells. The elevated expression and increased DNA binding activity of HIF-1alpha, the overexpression of its downstream target EPO may be the molecular mechanism in tolerance of PC12 cells to ischemia induced by ASE pretreatment.</p>