Objective: To evaluate the influence of up-regulation of glucose regulated protein 78 (GRP 78) induced by 2-deoxyglucose (2DG) on fetal rat cerebral neuron apoptosis following intrauterine distress and the unification of endoplasmic reticulum and mitochondrium.
Methods: (1) Fetal rat intrauterine distress model was established and rats were divided into normal group (N = 10), ischemia- reperfusion(IR) group (n = 40) and treatment group (n = 40, injection of 2DG into pregnant rats' abdomen after operation ). (2) Neuron apoptosis and the influence of 2DG on apoptosis was detected by terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) staining. The expression of GRP78, caspase-9, -12, and cytoron C protein were detected by western blot technique.
Results: (1) The number of TUNEL positive neuron in normal group was 4.3 +/- 1.8/mm2. The expression of GRP78, caspase-9, -12, cytoron C in cytoplasm were 0.012 +/- 0.003, 0.004 +/- 0.003, 0.006 +/- 0.002, 0.012 +/- 0.005, respectively. (2) The number of TUNEL positive neuron in the IR group were 43.6 +/- 11.4/mm2 (reperfusion 3 h), 64.4 +/- 9.3/mm2 (reperfusion 6 h), 74.2 +/- 12.1/mm2 (reperfusion 12 h), 97.3 +/- 8.9/ mm2 (reperfusion 24 h), respectively. They were significantly more than that in normal group (P < 0.05). The expression of GRP78 at corresponding times in IR group were 0.092 +/- 0.008 (reperfusion 3 h), 0.078 +/- 0.006 (reperfusion 6 h), 0.054 +/- 0.009 (reperfusion 12 h), 0.038 +/- 0.007 (reperfusion 24 h), respectively. The expression of cytoron C in cytoplasm at corresponding times in IR group were 0.040 +/- 0.006 (reperfusion 3 h), 0.076 +/- 0.009 (reperfusion 6 h), 0.108 +/- 0.005 (reperfusion 12 h), 0.089 +/- 0.008 (reperfusion 24 h), respectively. The expression of caspase-9 at corresponding times in IR group were 0.042 +/- 0.003 ( reperfusion 3 h), 0.086 +/- 0.007 (reperfusion 6 h), 0.142 +/- 0.006 (reperfusion 12 h), 0.112 +/- 0.009 (reperfusion 24 h), respectively. The expression of caspase-12 at corresponding times in IR group were 0.076 +/- 0.006 (reperfusion 3 h), 0.113 +/- 0.010 (reperfusion 6 h), 0.125 +/- 0.005 (reperfusion 12 h), 0.057 +/- 0.008 (reperfusion 24 h), respectively. They were significantly higher than that in normal group (P < 0.05). (3) The number of TUNEL positive neuron in the treatment group were 19.4 +/- 10.6/mm2 (reperfusion 3 h), 26.4 +/- 12.3 /mm2 (reperfusion 6 h), 39.3 +/- 13.3/mm2 (reperfusion 12 h), 49.3 +/- 13.6/mm2 (reperfusion 24 h), respectively. They were significantly lower than that in IR group, but more than that in normal group (P < 0.05). The expression of GRP78 at corresponding times in the treatment group were 0.158 +/- 0.012 (reperfusion 3 h), 0.175 +/- 0.005 (reperfusion 6 h), 0.125 +/- 0.013 (reperfusion 12 h), 0.079 +/- 0.004 (reperfusion 24 h), respectively. They were significantly higher than that in IR group and normal group (P < 0.05) . The expression of cytoron C in cytoplasm at corresponding times in IR group were 0.026 +/- 0.002 (reperfusion 3 h), 0.042 +/- 0.008 (reperfusion 6 h), 0.062 +/- 0.007 (reperfusion 12 h), 0.045 +/- 0.004 (reperfusion 24 h), respectively. The expression of caspase-9 at corresponding times in IR group were 0.033 +/- 0.002 (reperfusion 3 h), 0.063 +/- 0.005 (reperfusion 6 h), 0.092 +/- 0.005 (reperfusion 12 h), 0.068 +/- 0.008 (reperfusion 24 h), respectively. The expression of caspase-12 at corresponding times in IR group were 0.061 +/- 0.004 (reperfusion 3 h), 0.068 +/- 0.009 (reperfusion 6 h), 0.072 +/- 0.007 (reperfusion 12 h), 0.054 +/- 0.005 (reperfusion 24 h), respectively. They were significantly lower than that in IR group, but higher than that in normal group (P < 0.05).
Conclusions: Fetal rat cerebral neuron apoptosis following intrauterine distress is associated with the action of endoplasmic reticulum and mitochondrium. Up-regulation of GRP78 induced by 2DG counteracts primary cellular damage caused by endoplasmic reticulum stress. 2DG plays a protective role for fetal rat cerebral neuron following intrauterine distress.