BACKGROUND:Previous studies have shown that kainic acid injected into hippocampus can significantly upregulate the expression of excitatory KA1 subunit of the kainate receptor in the hippocampus, and endoplasmic reticulum stress markers, phosphorylation of the alpha subunit of eukaryotic initiation factor 2, accompanied by celldeath. OBJECTIVE:To explore the mechanism of endoplasmic reticulum stress after kainic acid is injected into the hippocampus.METHODS:0.15 nmol kainic acid was injected into the hippocampal CA1 region of 32 adult male Kunming mice, the injection time was 60 seconds. At different time points (1, 2, 3, 4, 5, 6, 8 and 12 hours) after kainic acid was injected, the Bederson score analysis was performed, and then the brain was harvested after cerebral perfusion. FJB staining of brain sections and immunofluorescence double labeled observation were also performed. RESULTS AND CONCLUSION:(1) At 3, 4, 5, 6, 8 hours after kainic acid injection, Bederson score showed severe injury of central nervous system function, and FJB staining showed the increased of celldeath in the hippocampus (P<0.05);At 1, 2, 12 hours after injection, Bederson score showed no obvious injury of central nervous system function, and FJB staining showed unobvious celldeath in the hippocampus (P>0.05). (2) According to the results of FJB staining, the brain sections were selected at 3, 8 hours for immunohistochemistry. The expressionlevels of KA1 receptors and endoplasmic reticulum stress marker P-eIF2αwere up-regulated at the same time after kainic acid was injected into hippocampus. Two single-staining KA1 and P-eIF2αimmunofluorescence images were synthesized into one over-lapped double-stained image, and two images overlapped, indicating that the up-regulated expression of KA1 and endoplasmic reticulum stress occurred in the same nerve cells. Kainic acid first up-regulated the excitatory receptor KA1 expression, which may cause cellendoplasmic reticulum dysfunction and result in the endoplasmic reticulum stress response, further promoting neuronal celldeath.

Objective To explore the clinical characteristics of monochorionic or dichorionic twin pregnancy and the high-risk factors for selective intrauterine growth restriction.Methods 460 women with twin pregnancy were divided into a monochorionic group and a dichorion group.The related clinical features were compared between the two groups.Logistic regression was used to analyze the high-risk factors for selective intrauterine growth restriction.Results The maternal age,conception way,and mode of delivery differed significantly between the two groups (P ＜ 0.05).There were significant differences in the rates of selective intrauterine growth restriction and preterm premature rupture of membranes (P ＜ 0.05).The neonatal weight (large or small) and the rate of neonatal transfer differed significantly (P ＜ 0.05).Logistic regression showed that gestational age and birth weight were the risk factors.Conclusions The chorionic nature plays an important role in the process and outcomes of maternal pregnancy.Monochorionic pregnancy is a high risk factor for selective intrauterine growth restriction,meaning the major cause of selective intrauterine growth restriction may originate from the placenta,with should be a placenta-derived disease.

OBJECTIVETo explore the effect of up-regulation of KA1 subunit of the kainate receptor on endoplasmic reticulum stress (ERS)-induced excitotoxic neurodegeneration in mouse hippocampus.

METHODSSeventy adult male KM mice were subjected to microinjections into the hippocampus of kainic acid (KA) or 500, 1000, or 2000 µg/ml tunicamycin (TM). At 1, 2, 3, 4, 5, 8, and 12 h after the injections, the mice were assessed for Bederson scores and sacrificed for FJB staining and immunofluorescence observation of the brain slices.

RESULTSAt 3, 4, 5, and 8 h after KA injection and at 4 and 5 h after of 2000 µg/ml TM injection, the mice showed severe central nervous system dysfunction, and FJB staining revealed increased cell death in the hippocampus, where up-regulated expressions of KA1 receptor and ERS marker P-eIF2α were found by immunofluorescence staining (P<0.05).

CONCLUSIONMicroinjection of KA or TM into the hippocampus causes neuronal death and ERS with up-regulated expression of KA1. In this process of neuronal apoptosis, the membrane receptor KA1 receives the apoptosis signal and transfers it to the inside of the cells to cause cell endoplasmic reticulum dysfunction and ERS response, which ultimately leads to neuronal death.

Animals ; Apoptosis ; Endoplasmic Reticulum Stress ; Hippocampus ; pathology ; Kainic Acid ; pharmacology ; Male ; Mice ; Neurons ; pathology ; Receptors, Kainic Acid ; metabolism ; Tunicamycin ; pharmacology ; Up-Regulation

Objective:To investigate the serum metabolites and their metabolic characteristics of patients with optic neuritis.Methods:Case-control study. From January 2021 to January 2022, 9 serum specimens of diagnosed patients with optic neuritis were collected in Department of Neurology from Beijing Tongren Hospital and 9 healthy subjects as the control. Among them, there were 5 females and 4 males in the optic neuritis group, aged (35.8±12.9) years; there were 5 females and 4 males in the healthy control group, aged (32.6±8.6) years. Liquid chromatography-mass spectrometry was used to detect metabolites in serum of healthy control and patients with optic neuritis. The principal component analysis (PCA) and orthogonal partial least-squares discriminination analysis (OPLS-DA) were used to analyze the differential metabolites . The variable importance projection value of OPLS-DA model and the P value of t-test was applied to find the different metabolites. Results:Thirty-seven metabolites were finally identified from serum samples. Four metabolites with variable important in projection (VIP) values larger than 1 and P values less than 0.05 were teased out, three metabolites, LysoPC (P-16∶0), LysoPC (16∶0), LysoPC (P-18∶0) belonge to phospholipid and one metabolite was L-Threonine, they were all down-regulated. The area under curve were 0.951, 0.889, 0.963 and 0.944, respectively. Conclusion:Based on metabonomic analysis, some metabolites in serum have changed, which can provide basis for biomarkers screening of optic neuritis.