[Up-regulation of glucose regulated protein 78 induced by 2-deoxyglucose plays a protective role for fetal rat cerebral neuron following intrauterine distress].

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.