Association between interleukin-6 gene promoter -572C/G polymorphism and the risk of sporadic Alzheimer's disease.

Inflammation is a key component of Alzheimer's disease (AD), and we have examined the effect of two polymorphisms (-174G/C and -572C/G) in the promoter of the inflammatory cytokine interleukin-6 (IL-6) gene on risk of AD in 318 AD patients. Significant differences in genotype and allele frequencies of -572C/G IL-6 promoter polymorphism were observed between AD patients and controls. The GG genotype was associated with a decreased risk of developing AD (OR 0.423, 95% CI 0.200-0.894). Similarly, logistic regression analysis revealed that G allele was a protective factor for AD (OR 0.732, 95% CI 0.567-0.945). For -174G/C variability, no C variability was found in all the subjects. The frequency of the IL-6 -174G/C promoter polymorphism is very low or no variability in Henan Han population. The -572C/G polymorphism of IL-6 gene promoter region is associated with AD, and G allele is an independent protective factor for AD.

[Changes in DNA repair enzymes in rat ventroposterior nucleus of the thalamus after cerebral cortex infarction].

OBJECTIVE: To investigate the damage within the ventroposterior nucleus (VPN) of the thalamus after focal cortical infarction and its mechanism, and explore the effect of ebselen on the oxidative damage after cerebral cortex infarction in hypertensive rats. METHODS: Middle cerebral artery occlusion (MCAO) was induced in stroke-prone renovascular hypertensive rats (RHRSP), and the rats were divided into four groups by table of random number: sham operation group, model group, vehicle group and ebselen group, each group consisted of 8 rats. In animals subjected to sham surgery the middle cerebral artery was exposed only. Ebselen (5 ml/kg) or vehicle (a mixed solvent consisting of 0.5% carboxymethyl cellulose and 0.02% Tween 20, 5 ml/kg) was given by gastric gavage starting 24 hours after cerebral cortical infarction. Two weeks after the MCAO, the rats were sacrificed, and VPN from each group was sectioned and stained with hematoxylin-eosin (HE), and apurinic/apyrimidinic endonuclease (APE) and Escherichia coli MutY DNA glycosylase (MYH) were determined by immunohistochemistry. RESULTS: HE staining showed that ebselen ameliorated the VPN damage induced by ischemia. Immunohistochemical imaging analysis revealed a distinct nuclear staining of APE and nuclear and cytoplasm distribution of MYH in the entire region of the VPN. Compared with sham operation group, the number of APE and MYH positive cells decreased in model group and vehicle group (APE: 57.0±14.7, 49.4±12.5 vs. 101.0±13.6, MYH: 15.0±4.7, 10.4±2.5 vs. 56.0±13.2, all P<0.05). Compared with model group and vehicle group, the number of APE and MYH positive cells increased significantly in ebselen group (APE: 72.2±7.6 vs. 57.0±14.7, 49.4±12.5, MYH: 32.2±7.6 vs. 15.0±4.7, 10.4±2.5, all P<0.05); the difference of the number of APE and MYH positive cells between model group and vehicle group showed no statistical significance. CONCLUSION: After 2 weeks of MCAO, there is a marked decrease of APE and MYH in VPN; ebselen can obviously increase the level of APE and MYH, and ebselen may protect the VPN of the thalamus from damage after focal cortical infarction in rats.

[EphB2-Fc promotes activation of endogenous neural stem cells after cerebral cortex infarction: experimental with hypertensive rats].

OBJECTIVE: To explore the effects of intraventricular injection of EphB2-Fc on activation of inherent neural stem cells after cerebral cortex infarction. METHODS: Stroke-prone renovascular hypertension model was established in 96 SD rats by two-kidney, two-clip method. Middle cerebral artery occlusion (MCAO) model was established in 72 of these 96 stroke-prone renovascular hypertensive rats and the other 24 rats were used as sham operation group. Then the 72 rats were randomly divided into 3 equal groups: cerebral infarction group without any treatment after the MCAO, MCAO + EphB2-Fc group undergoing stereotaxical infusion of EphB2-Fc at the dose of 20 microl x 200 microg/ml into the lateral ventricle 4 days after the distal ligation of right middle cerebral artery, and MCAO + IgG-Fc group undergoing stereotaxical infusion of IgG-Fc at the dose of 20 microl x 200 microg/ml into the lateral ventricle 4 days after the distal ligation of right middle cerebral artery. By the ends of the first and fourth weeks after the MCAO procedure 12 rats from each group were killed and their brains were taken out to undergo in situ hybridization, immunohistochemistry and Western blotting analysis in order to determine the expression of EphB2 protein and mRNA, nestin and polysialic acid-neural cell adhesion molecule (PSA-NCAM). RESULTS: One week after the distal ligation of right middle cerebral artery, the EphB2 protein and mRNA expression levels in the ipsilateral cortex and subventricular zone (SVZ) of the cerebral infraction group were both lower than those of the sham operation group (P < 0.05), such levels of the MCAO + EphB2-Fc group were higher than those of the MCAO + IgG-Fc group (both P < 0.05), but there was no significant difference between the cerebral infraction group and IgG-Fc group (both P > 0.05), and there were no differences in such levels between the cerebral infarction group and MCAO + IgG-Fc group (both P > 0.05); the nestin and PSA-NCAM expression levels in the ipsilateral SVZ of the cerebral infraction group were both higher than those of the sham operation group (both P < 0.05), such levels of the MCAO + EphB2-Fc group were both higher than those of the MCAO + IgG-Fc group (both P < 0.05), and migration of PSA-NCAM positive cells to corpus callosum could be seen. Four weeks after, there were no significant differences in the expression levels of EphB2 protein and mRNA among different groups (all P > 0.05), the nestin and PSA-NCAM expression levels in the ipsilateral SVZ decreased in all groups, there were no significant differences in the expression of nestin among all groups, but the PSA-NCAM expression in the ipsilateral SVZ of the cerebral infraction group was still higher than that of the sham operation group. CONCLUSION: Disruption of EphB2 signal promotes the proliferation and migration of endogenous neural stem cells in the SVZ after cerebral cortex infarction.

[Observation on tissue factor pathway during the onset of acute cerebral infarction].

OBJECTIVE: To establish the possible relationship between some coagulation factors and the onset of acute cerebral infarction (ACI). METHODS: The study population consisted of 71 patients with ACI confirmed by CT and 50 age-matched healthy volunteers. Blood samples were obtained during the onset period of ACI. Tissue factor (TF) and tissue factor pathway inhibitor (TFPI) activity in plasma were assayed with the chromogenic assay. Plasma TF and TFPI antigen were measured with enzyme linked immunoadsorbent assay (ELISA). Plasma F VII coagulation activity (F VII: C) and F VIII coagulation activity (F VIII: C) were developed in the one-stage system. Plasma prothrombin (FII) was determined with Ecarin assay. Plasma fibrinogen (Fbg) was measured with thrombin assay. Plasma antithrombin III activity (ATIII) was determined using heparin cofactor activity assay. RESULTS: Compared with the control, plasma TF activity and antigen in patients with ACI were significantly higher (both P<0.05). But plasma TFPI activity and antigen were remarkably lower in the ACI group (both P<0.05). Plasma F VII: C was significantly higher (P<0.01), and F VIII: C was markedly lower (P<0.05). Plasma FII was remarkably higher (P<0.01). Similarly the Fbg was significantly higher in the ACI than that in the control group (P<0.01), whereas ATIII was significantly lower (P<0.01). CONCLUSION: The initiation of TF pathway is contributed to the onset of ACI and the blood is in hypercoagulable state during the early period of ACI.

[Effect of angiotensin II on tissue factor expression in human peripheral blood monocytes and its mechanisms].

OBJECTIVE: To elucidate the effect of angiotensin II (AngII) on the expression of tissue factor (TF) by monocytes and its mechanisms. METHODS: Monocytes were isolated from healthy volunteers by Ficoll-Hypaque gradient and Percoll, and cultured in RPMI-1640. Procoagulant activity (PCA) was determined by one-stage clotting method, TF antigen by ELISA. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect the TF gene mRNA. The levels of IkappaBalpha was detected by Western blot. Electrophoretic mobility shift assays (EMSA) were performed to evaluate the activity of NF-kappaB. RESULTS: AngII (10(-9) - 10(-7) mol/L) significantly increased monocyte PCA, TF antigen and TF mRNA expression in a dose and time dependent manner. Losartan (10(-6) - 10(-5) mol/L) significantly inhibited the effects of AngII on TF activity, antigen and mRNA expression in a dose-dependent effects. Staurosporine (2.5 x 10(-7) mol/L) and genistein (4 x 10(-5) mol/L) lowered TF level of monocytes (P < 0.05). Western blot analysis revealed that after exposure to AngII (10(-7) mol/L), IkappaBalpha level decreased at 15 min, reached nadir at 60 min, and recovered at 180 min. EMSA showed NF-kappaB binding activity increased at 15 min, reached peak at 60 min, and recovered at 180 min. Pyrrolidine dithiocarbamate (PDTC, 10(-4) mol/L), an inhibitor of NF-kappaB, or AT1R antagonist losartan (10(-5)mol/L) inhibited AngII-induced NF-kappaB translocation. CONCLUSIONS: AngII could induce the expression of TF in human monocytes, and this effect was mediated by AT1R. The PKC pathway played the most important role in AngII-induced TF expression. The activation of NF-kappaB was involved in TF expression in monocytes.