The Effect Of Rat Prenatal Alcohol On Offspring Cerebral Cortex Endoplasmic Reticulum Stress Proteins And Cell Apoptosis

Objective: The fetal alcohol syndrome caused by maternal alcoholism is one of serious consequences by alcohol on the central nervous system.It has been showed as neurodegeneration,apoptosis and degeneration necrosis in neuronal,disorder of differentiation and migration in neuronal systems.But the mechanism of these pathological changes is still not clear.Previous studies have indicated that there is a causal relationship between the pathological changes induced by alcohol and the endoplasmic reticulum stress response,but there is a lack of detailed reports.Endoplasmic reticulum is the main organelle for protein synthesis,processing and for storing Ca²⁺.Stress hormones,oxygen free radical and cytokines can interfere with the function of endoplasmic reticulum,which lead to unfolded or misfolded proteins accumulating in the ER.The increased expression of endoplasmic reticulum stress protein,such as glucose regulating protein 78?GRP78?,phosphorylated eukaryotic translation initiation factory 2??p-eIF2??and C/EBP-homologous protein?CHOP?,can activate ERS.Although ERS is an important component of cellular defense adaptation,prolonged or severe ERS can induce apoptosis,inflammation and other pathological changes.Current research has suggested that GRP78,p-eIF2?,CHOP are the important regulatory proteins in starting endoplasmic reticulum stress pathway,and increased expression of CHOP especially makes the endoplasmic reticulum stress reaching its peak,which can activate the apoptosis by inducing apoptotic factors.However,there is not detailed that the effect of rat maternal alcoholism on offspring cerebral endoplasmic reticulum stress proteins and cell apoptosis.Therefore,the study,on the context of established models of rat prenatal alcohol,was to investigate the changes of GRP78?P-eIF2? and CHOP and cell apoptosis in the cerebral cortex of offspring.It is meaningful to investigate whether endoplasmic reticulum stress is associated with cell apoptosis induced by alcohol toxicity,which is finally to provide a scientific basis for preventing of nerve injury due to ethanol.Methods: 1 Adult female Wistar rats,weighing 260 ± 10 g,were used to study.The rats were randomly divided into the normal control group and drinking group.During the experiment,the control group has been using distilled water feeding.The drinking group began to give 10% concentration of alcohol,and increased alcohol concentration 1% daily,until the concentration is 20%.Using the method of vaginal smear test to detect the vaginal exfoliated epithelial cells of female rats,to determine the rat estrous cycle.After determining females in the heat,female mice were mated with mature males in ratio of 1:1,from the 20:00 to the next 8:00 for 12 hours.At the end of the mating period,females were examined for the presence of a vaginal plug.The pregnant rats of drinking group were fed 20% concentration of alcohol,until the end of pregnancy.In order to ensure the alcohol concentration,the daily 8:00 to replace the fresh alcohol solution,which was preparation by Beijing Hongxing wine of 56% and distilled water.After models were established,the brain tissues of two groups that born at 3day?3d?,7day?7d?,11day?11d?,were taken to fixation,dehydration,transparent,embedding and slicing.1.1 Hematoxylin eosin?HE?staining was used to observe the conventional pathology changes.1.2 Immunohistochemical staining was used to detect the expression changes of related proteins.1.3 Terminal deoxynucleotidyl transferase-mediated d UTP nick-end-labeling?TUNEL?was used to detected apoptosis of nerve cells.2 Statistical methodsWith SPSS13.0 statistical program,the data was presented as mean ± SD.The data was analyzed by using one-way analysis of variance?ANOVA?and least significant difference?LSD?to determine specific group differences.The threshold for statistical significance was defined as P < 0.05.Results:1 Results of conventional histopathological observation?HE staining?The cerebral cortex neuronal cells arranged neatly,no lack of edema,deletion and other pathological changes in the control group of newborn rats at 3d,7d,11 d.However,the cerebral cortex neurons were irregular and edema,part of nerve cells were decreased or even pyknosis in the drinking group of newborn rats at 3d,7d,11 d.2 Results of GRP78 immunohistochemical stainingPart of cerebral cortex neurons can be found positive expression in the control group of newborn rats at 3d,7d,11 d.Compared with the corresponding time of the control group,the number of positive cells increased in the drinking group.3 Results of p-e IF2? immunohistochemical stainingA few of cerebral cortex neurons can be found positive expression in the cytoplasm in the control group of newborn rats at 3d,7d,11 d.Compared with the corresponding time of the control group,the positive expression enhanced obviously,and the number of positive cells increased significantly in the drinking group.4 Results of CHOP immunohistochemical stainingCompared with the corresponding time of the control group,the positive expression enhanced obviously and the number of positive cells increased significantly in the drinking group of newborn rats at 3d,7d,11 d.5 TUNEL stainingA few scattered apoptotic cells were observed in the control group of newborn rats at 3d,7d,11 d.Compared with the corresponding time of the control group,the number of apoptotic cells in the cerebral cortex was significantly increased in the drinking group.Conclusion:The study was successfully established the model of rat prenatal alcohol.Used the routine histopathology,immunoh-istochemistry and TUNEL staining,we got the conclusions as follows: drinking during pregnancy could resulted in the cerebral cortex neuronal cells of newborn rat arranged disorder,edema and pyknosis.Endoplasmic reticulum stress is involved in the pathological changes of offspring cerebral cortex neurons caused by drinking during pregnancy,the expression changes of endoplasmic reticulum stress protein such as GRP78,p-eIF2? and CHOP,can activate the apoptosis by inducing apoptotic factors.