Lysophosphatidylcholine induces apoptosis and inflammatory damage in brain microvascular endothelial cells via GPR4-mediated NLRP3 inflammasome activation.

Lysophosphatidylcholine (LPC), as the main active component of oxidized low-density lipoproteins (ox-LDLs), has significant effects in cerebrovascular disease. However, the complex mechanism by which LPC functions in brain microvascular endothelial cells (BMECs) is not clearly understood. In this study, BMECs were transfected with G protein-coupled receptor 4 (GPR4) siRNA or an NLRP3-overexpression plasmid, and GPR4 expression was identified by RT-qPCR and western blotting; IL-1ß, IL-18, and IL-33 levels were evaluated by ELISA. Apoptosis was monitored by flow cytometry and Hoechst staining, while Caspase 3, ASC, NLRP3, and GPR4 protein expression were examined by western blotting. Our results showed that LPC significantly increased the levels of inflammatory cytokines (IL-1ß, IL-18, and IL-33) and markedly induced apoptosis and NLRP3 inflammasome activation in BMECs. Moreover, LPC notably upregulated GPR4 in BMECs, and knockdown of GPR4 significantly attenuated the effects of LPC in BMECs. Above all, we also proved that LPC induced apoptosis and inflammatory injury in BMECs by causing GPR4 to activate NLRP3 inflammasomes. Therefore, GPR4-mediated activation of NLRP3 inflammasomes might be the underlying mechanism by which LPC promotes the progression of cerebrovascular disease. In summary we found that LPC is an important pathogenic factor in cerebrovascular disease, and can induce GPR4 to active NLRP3 inflammasomes.

The Impacts of Peptic Ulcer on Functional Outcomes of Ischemic Stroke.

BACKGROUND AND PURPOSE: Studies have shown that peptic ulcer increased the risk of ischemic stroke and stroke recurrence. This study aimed to evaluate the impacts of peptic ulcer on functional outcomes of ischemic stroke. METHODS: Patients with first-ever ischemic stroke were grouped as with and without history of peptic ulcer. Functional outcomes were evaluated with modified Rankin scale at 90 days after the index stroke. Favorable functional outcomes were defined as with a modified Rankin scale score of 0-2. Logistic regression was used to identify predictors for favorable functional outcomes at 90 days. RESULTS: Among the 2577 enrolled patients with ischemic stroke, 129 (5.0%) had a history of peptic ulcer. The proportion of favorable outcome was higher in patients without peptic ulcer than those with (59.3% versus 42.6%, P < .001). Multivariate logistic analysis detected that history of peptic ulcer (odds ratio [OR] = 2.89, 95% confidence interval [CI], 1.03-8.10, P = .043), National Institute of Health Stroke Scale score (OR = 2.11, 95% CI, 1.79-2.48, P < .001), and large-artery atherosclerosis stroke subtype (OR = 4.08, 95% CI, 1.11-15.03, P = .035) decreased the likelihood of favorable outcomes. CONCLUSIONS: Ischemic stroke patients with peptic ulcer may have an increased risk of less favorable neurological outcome at 90 days after the index stroke.

The Impacts of Peptic Ulcer on Stroke Recurrence.

BACKGROUND: Peptic ulcer has been associated with an increased risk of stroke. This study aimed to evaluate the impacts of peptic ulcer on stroke recurrence and mortality. SUBJECTS AND METHODS: Patients with first-ever ischemic stroke were retrospectively confirmed with or without a history of peptic ulcer. The primary end point was defined as fatal and nonfatal stroke recurrence. Risks of 1-year fatal and nonfatal stroke recurrence were analyzed with the Kaplan-Meier method. Predictors of fatal and nonfatal stroke recurrence were evaluated with the Cox proportional hazards model. RESULTS: Among the 2577 enrolled patients with ischemic stroke, 129 (5.0%) had a history of peptic ulcer. The fatal and nonfatal stroke recurrence within 1 year of the index stroke was higher in patients with peptic ulcer than in patients without peptic ulcer (12.4% versus 7.2%, P = .030). Cox proportional hazards model detected that age (hazard ratio [HR] = 1.018, 95% confidence interval [CI] 1.005-1.031, P = .008), hypertension (HR = 1.397, 95% CI 1.017-1.918, P = .039), and history of peptic ulcer (HR = 1.853, 95% CI 1.111-3.091, P = .018) were associated with stroke recurrence. CONCLUSIONS: Ischemic stroke patients with peptic ulcer may have an increased risk of stroke recurrence. The results emphasize the importance of appropriate prevention and management of peptic ulcer for secondary stroke prevention.

Association of GWAS-Supported Variants rs556621 on Chromosome 6p21.1 with Large Artery Atherosclerotic Stroke in a Southern Chinese Han Population.

Recent genome-wide association study associated rs556621 on chromosome 6p21.1 with the risk of large artery atherosclerotic (LAA) stroke in Caucasians. However, subsequent replicate studies showed conflict results in different ethnicities. This study aimed to evaluate whether rs556621 was associated with LAA stroke in Chinese Han population. In this case-control study, 659 patients with LAA stroke and 650 healthy controls were enrolled. Associations between rs556621 genotypes and LAA stroke were analyzed with logistic regression model. Rs556621 variants were associated with increased risks of LAA stroke (codominant model: OR 1.42; 95 % CI 1.01-1.99; P = 0.010; recessive model: OR 1.40; 95 % CI 1.05-1.86; P = 0.003). When subjects were stratified by sex, TT genotype of SNP rs556621 was associated with an increased risk of LAA stroke in female when tested with recessive model (OR 2.36; 95 % CI 1.28-4.36, P = 0.006). In male subjects, however, no significant association was detected. Smoking status, sex did not significantly influence the relationship between genotypes of rs556621 and risk of LAA stroke (P interaction = 0.140, P interaction = 0.076). Rs556621 may play an important role in the development of LAA stroke in female Chinese of Han ethnicity. Larger studies with subjects of different ethnicities are warranted to confirm these findings.

Tissue Kallikrein Alleviates Cerebral Ischemia-Reperfusion Injury by Activating the B2R-ERK1/2-CREB-Bcl-2 Signaling Pathway in Diabetic Rats.

Diabetes mellitus (DM) substantially increases the risk of ischemic stroke and reduces the tolerance to ischemic insults. Tissue kallikrein (TK) has been demonstrated to protect neurons from ischemia/reperfusion (I/R) injury in orthoglycemic model by activating the bradykinin B2 receptor (B2R). Considering the differential effects of B2R or bradykinin B1 receptor (B1R) on cardioprotection and neuroprotection in I/R with or without diabetes, this study was designed to investigate the role of TK during cerebral I/R injury in streptozotocin-induced diabetic rats. Intravenous injection of TK inhibited apoptosis in neurons, alleviated edema and inflammatory reactions after focal cerebral I/R, significantly reduced the infarct volume, and improved functional recovery. These beneficial effects were accompanied by activation of the extracellular signal-regulated kinase 1/2 (ERK1/2), cAMP response element-binding (CREB), and Bcl-2 signal proteins. Inhibition of the B2R or ERK1/2 pathway abated the effects of TK, whereas an antagonist of B1R enhanced the effects. These findings reveal that the neuroprotective effect of TK against cerebral I/R injury in streptozotocin-induced diabetic rats mainly involves the enhancement of B2R and ERK1/2-CREB-Bcl-2 signaling pathway activity.

Effects of Feeder Cells on Dopaminergic Differentiation of Human Embryonic Stem Cells.

Mouse embryonic fibroblasts (MEFs) and human foreskin fibroblasts (HFFs) are used for the culture of human embryonic stem cells (hESCs). MEFs and HFFs differed in their capacity to support the proliferation and pluripotency of hESCs and could affect cardiac differentiation potential of hESCs. The aim of this study was to evaluate the effect of MEFs and HFFs feeders on dopaminergic differentiation of hESCs lines. To minimize the impact of culture condition variation, two hESCs lines were cultured on mixed feeder cells (MFCs, MEFs: HFFs = 1:1) and HFFs feeder, respectively, and then were differentiated into dopaminergic (DA) neurons under the identical protocol. Dopaminergic differentiation was evaluated by immunocytochemistry, quantitative fluorescent real-time PCR, transmission and scanning electron microscopy, and patch clamp. Our results demonstrated that these hESCs-derived neurons were genuine and functional DA neurons. However, compared to hESCs line on MFCs feeder, hESCs line on HFFs feeder had a higher proportion of tyrosine hydroxylase (TH) positive cells and expressed higher levels of FOXA2, PITX3, NURR1, and TH genes. In addition, the values of threshold intensity and threshold membrane potential of DA neurons from hESCs line on HFFs feeder were lower than those of DA neurons from hESCs line on the MFCs feeder. In conclusion, HFFs feeder not only facilitated the differentiation of hESCs cells into dopaminergic neurons, but also induced hESCs-derived DA neurons to express higher electrophysiological excitability. Therefore, feeder cells could affect not only dopaminergic differentiation potential of different hESCs lines, but also electrophysiological properties of hESCs-derived DA neurons.

Evaluation on the compliance with secondary prevention and influence factors of ischemic stroke in Hainan province, China.

Survivors of ischemic stroke are still at a significant risk for recurrence. Numerous effective strategies for the secondary prevention of ischemic stroke have now been established; however, these guidelines are not widely known. In this retrospective, a multicenter study was conducted from January 2011 to February 2012 in 10 general hospitals, which included 1300 elderly patients who had previously been diagnosed with ischemic stroke and re-admitted to hospitals. Logistic regression models were fitted to determine the relationship between compliance with secondary prevention therapy and each variable of interest. The treatment rates of antihypertensive, antiplatelet and lipid-lowering therapy were only 56.3%, 48.9% and 19.6%, respectively. Multivariate analysis presented that cardiovascular risk factors would motivate patients with hypertension and hyperlipidemia to receive corresponding treatments. However, it is worth noting that they did not influence the use of antiplatelet therapy. In addition, high education, health education and insurance promote the use of secondary prevention in patients. In conclusion, the importance of antiplatelet therapy should not be ignored any more. Besides, health education will raise patients' attention to ischemic stroke.

Prevention of stroke and systemic embolism with rivaroxaban compared with warfarin in Chinese patients with atrial fibrillation.

This study assessed the effects and safety of rivaroxaban versus warfarin in Chinese patients with atrial fibrillation. In this double-blind clinical trial, a total of 353 consecutive patients with atrial fibrillation who were at risk of stroke or systemic embolism were enrolled to receive either rivaroxaban or warfarin. The primary effect endpoint occurred in five patients in the rivaroxaban group (2.29% per year) and in seven patients in the warfarin group (2.91% per year) (hazard ratio with warfarin, 0.76, 95% CI, 0.64-0.91; p = 0.03). Major and non-major clinically relevant bleeding occurred in 38 patients (14.3% per year) in the rivaroxaban group and in 36 patients (13.7% per year) in the warfarin group (hazard ratio rivaroxaban versus warfarin, 1.07; 95% CI, 0.93-1.14; p = 0.39). Adverse events were similar between these two arms (p > 0.05). In conclusion, oral administration of rivaroxaban reduced the risk of stroke or systemic embolism without significantly increasing the safety concern.

Impact of minocycline on neurodegenerative diseases in rodents: a meta-analysis.

Minocycline is a semisynthetic second-generation tetracycline derivative, and many publications provide evidence of its successful neuroprotection in a variety of animal models. We searched PubMed and Chinese CNKI databases from January 1992 to May 2012 for studies on minocycline in neurodegenerative diseases in rodents. A meta-analysis that adopted weighted Cohen's d effect sizes, percent overlap, Fail-Safe N statistics, and confidence intervals was conducted. In total, 16 English and 3 Chinese articles with high or medium quality were included in this meta-analysis. The treatment benefits for rodents from low-dose (5 mg/kg/day), moderate-dose (45, 50, or 55 mg/kg/day), and high-dose (90 mg/kg/day) minocycline were larger in Huntington's disease, Alzheimer's disease, and stroke mouse models, respectively. In rats, a moderate dose (45 mg/kg/day) of minocycline was most effective. In conclusion, minocycline exerts neuroprotective effects in rodent models of neurodegenerative diseases. Anti-inflammatory, antiapoptotic, and antioxidant activities are discussed as the basis of this effect. However, there is insufficient information from these animal models on side effects of minocycline therapy.

[Adenovirus vector mediated human 14-3-3 γ gene transfer protects dopaminergic cells against rotenone-induced injury].

OBJECTIVE: To explore the protective effect of human 14-3-3 γ gene transfer on dopaminergic cells against rotenone-induced injury. METHODS: Adenovirus vector carrying the gene of 14-3-3 γ (Ad/14-3-3 γ) was employed to transfect PC12 cells. Then the cells were exposed to rotenone as a model of Parkinson's disease. Methyl thiazolyl tetrazolium (MTT) was used to assay the viability of PC12 cells. The 4',6-diamidino-2-phenylindole (DAPI) staining was used to analyze the apoptotic ratio of PC12 cells among the groups of control, Ad/14-3-3 γ, Ad-null and Rotenone. And high performance liquid chromatography (HPLC) was performed to detect the secreting functions of PC12 cells. The aggregates of α-Synuclein protein were detected under confocal microscopy. RESULTS: MTT showed that the cell absorbance A(570) of Ad/14-3-3 γ group (0.46 ± 0.09) was higher than that of Ad-null group (0.19 ± 0.08) and rotenone group (0.16 ± 0.07), but lower than that of normal control (0.63 ± 0.11), (all P < 0.01); HPLC-ECD showed that the levels of dopamine (189 ± 11) ng/ml and noradrenalin (55 ± 8) ng/ml in the culture fluid of Ad/14-3-3 γ group were higher than those of Ad-null group (79 ± 12, 38 ± 7) ng/ml and rotenone group (81 ± 13, 39 ± 7) ng/ml (all P < 0.01). DAPI staining showed that cell apoptosis ratio of group Ad/14-3-3 γ (27% ± 64%) was lower than that of group Ad-null (53% ± 10%) and rotenone group (56% ± 12%, P < 0.01), but higher than that of control group (10% ± 5%, P < 0.01). Under confocal microscopy, the aggregates of α-synuclein protein in PC12 cells were detected more in Ad-null group and rotenone group than that in Ad/14-3-3 γ group. CONCLUSION: Gene transfer of Ad/14-3-3 γ has a protective effect on dopaminergic cells against rotenone-induced injury.