NDRG2 promoted secreted miR-375 in microvesicles shed from M1 microglia, which induced neuron damage.

BACKGROUND: Microglia microvesicles (MVs) has shown to have significant biological functions under normal conditions. A diversity of miRNAs is involved in neuronal development, survival, function, and plasticity, but the exact functional role of NDRG2 and secreted miR-375 in MVs in neuron damage is poorly understood. We investigated the effect of NDRG2 and secreted miR-375 in MVs shed from M1 microglia on neuron damage. METHODS: Expression of Nos2, Arg-1, miR-375, syntaxin-1A, NDRG2 and Pdk 1 were evaluated using RT-PCR or western blotting. Cell viability of N2A neuron was quantified by a MTT assay. RESULTS: Microglia can be polarized into different functional phenotypes. Expression of NDRG2 and Nos2 were significantly increased by LPS treatment on N9 cells, whereas treatment with IL-4 dramatically suppressed the expression of NDRG2 and remarkably elevated expression of Arg-1. Besides, MVs shed from LPS-treated N9 microglia significantly inhibited cell viability of N2A neurons and expression of syntaxin-1A, and NDRG2 interference reversed the up-regulated miR-375 in LPS-treated N9 microglia and MVs shed from LPS-treated N9 cells. Furthermore, NDRG2 could modulate miR-375 expression in N9 microglia and MVs. And miR-375 inhibitor remarkably elevated Pdk1 expression in N2A neurons. Finally, miR-375 inhibitor could reverse suppression effect of NDRG2 overexpression on cell viability of N2A neurons and expression of syntaxin-1A. CONCLUSION: Our results demonstrated that NDRG2 promoted secreted miR-375 in microvesicles shed from M1 microglia, which induced neuron damage. The suppression of NDRG2 and secreted miR-375 in MVs shed from M1 microglia may be potential targets for alleviation of neuron damage.

Association between NADPH oxidase p22(phox) C242T polymorphism and ischemic cerebrovascular disease: a meta-analysis.

BACKGROUND: Epidemiological studies have evaluated the association between nicotinamide adenine dinucleotide phosphate (NADPH) oxidase p22(phox) C242T polymorphism and risk of ischemic cerebrovascular disease (ICVD), but the results remain inconclusive. This meta-analysis was therefore designed to clarify these controversies. METHODOLOGY/PRINCIPAL FINDINGS: Systematic searches of electronic databases Embase, PubMed and Web of Science, as well as hand searching of the references of identified articles and the meeting abstracts were performed. Statistical analyses were performed using software Review Manager (Version 5.1.7) and Stata (Version 11.0). The pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) were performed. Fixed or random effects model was separately used depending on the heterogeneity between studies. Publication bias was tested by Begg's funnel plot and Egger's regression test. A total of 6 studies including 1,948 cases and 2,357 controls were combined showing no statistical evidence of association between NADPH oxidase p22(phox) C242T polymorphism and overall ICVD (allelic model: OR = 1.08, 95%CI = 0.93-1.26; additive model: OR = 1.33, 95%CI = 0.81-2.17; dominant model: OR = 1.00, 95%CI = 0.86-1.15; recessive model: OR = 1.06, 95%CI = 0.77-1.45). Significant association was found in large-artery atherosclerotic stroke subgroup (allelic model: OR = 1.12, 95%CI = 0.88-1.41; additive model: OR = 1.36, 95%CI = 0.60-3.09; dominant model: OR = 1.25, 95%CI = 0.74-2.11; recessive model: OR = 2.17, 95%CI = 1.11-4.23). No statistical evidence of significant association was observed for small-vessel occlusive stroke, as well as Asian subgroup and Caucasian subgroup. Statistical powers on the combined sample size (total and subgroup) were all lower than 80%. CONCLUSIONS/SIGNIFICANCE: This meta-analysis indicates that NADPH oxidase p22(phox) C242T polymorphism is more associated with large-artery atherosclerotic stroke than small-vessel occlusive stroke. However, this conclusion should be interpreted with caution due to the small sample size. Larger sample-size studies with homogeneous ICVD patients and well-matched controls are required.

Association between interleukin-1α C(-889)T polymorphism and Alzheimer's disease: a meta-analysis including 12,817 subjects.

Epidemiological studies have evaluated the association between interleukin-1 (IL-1)α C(-889)T polymorphism and Alzheimer's disease (AD), but the results remain inconclusive. This meta-analysis was, therefore, designed to clarify these controversies. Systematic searches of electronic databases Embase, PubMed, and Web of Science as well as hand searching of the references of identified articles and the meeting abstracts were performed. Statistical analyses were performed using software Review Manager (Version 5.1.2) and Stata (Version 11.0). The pooled odds ratios (ORs) with 95 % confidence intervals (95 % CIs) were calculated. A total of 28 publications including 29 studies were involved. There was a significant association between IL-1α C(-889)T polymorphism and AD (for T allele vs. C allele: OR = 1.14, 95 % CI = 1.07-1.21; for T/T vs. C/C: OR = 1.39, 95 % CI = 1.18-1.63; for dominant model: OR = 1.13, 95 % CI = 1.04-1.22; and for recessive model: OR = 1.39, 95 % CI = 1.20-1.60). Significant association was found for Asians, Caucasians, and early-onset Alzheimer's disease (EOAD) but for late-onset Alzheimer's disease (LOAD). This meta-analysis indicates that there is a significant association between IL-1α C(-889)T polymorphism and AD as well as EOAD.

Association between apolipoprotein E gene polymorphism and the risk of multiple sclerosis: a meta-analysis of 6977 subjects.

Epidemiological studies have evaluated the association between apolipoprotein E (ApoE) gene polymorphism and multiple sclerosis (MS) risk. However, the results remain conflicting. Therefore, in order to derive a more precise association of ApoE gene polymorphism with MS risk, we performed this meta-analysis. Systematic searches of electronic databases PubMed, Embase and Web of Science, as well as hand searching of the references of identified articles were performed. Twenty studies were identified, covering a total of 4080 MS cases and 2897 controls. The results showed evidence for significant association between ApoE ε2 mutation and MS risk (for ε2/ε4 versus ε3/ε3: OR=1.74, 95% CI=1.12-2.71, p=0.01; for ε2 allele versus ε3 allele: OR=1.16, 95% CI=1.01-1.35, p=0.04). In the subgroup analysis by ethnicity, the similar results were obtained among Europeans (for ε2/ε4 versus ε3/ε3: OR=1.81, 95% CI=1.14-2.87, p=0.01; for ε2 allele versus ε3 allele: OR=1.19, 95% CI=1.02-1.38, p=0.03). After excluding the outlier studies by observing Galbraith plot, marginal association was found between ApoE ε3/ε4 genotype and the protective factor for MS (for ε3/ε4 versus ε3/ε3: OR=0.86, 95% CI=0.75-0.99, p=0.04). In summary, the present meta-analysis provides evidence that ApoE ε2 mutation is associated with MS risk. In addition, ApoE ε3/ε4 genotype appears to be a protective factor for MS.

Association between estrogen receptor alpha c.454-397T>C and c.454-351A>G and ischemic stroke risk: a systematic review and meta-analysis.

The association between estrogen receptor alpha (ESR1) c.454-397T>C and c.454-351A>G polymorphism and ischemic stroke remains controversial. The aim of this study was to perform a meta-analysis to investigate a more authentic association between c.454-397T>C and c.454-351A>G mutation and ischemic stroke. Systematic searches of electronic databases Embase, PubMed, Web of Science as well as hand-searching of the references of identified articles and the meeting abstracts were performed. Study selection, data abstraction and study quality evaluation were independently conducted in duplicate. Statistical analyses were performed using software Stata 11.0. The pooled odds ratios (ORs) with 95 % confidence intervals (95 % CIs) were performed. Different effect models were used according to the difference in heterogeneity. Publication bias was tested by Begg's funnel plot and Egger's regression test. For c.454-397T>C mutation, five studies were combined. Significant association was found in allelic model (OR = 1.12, 95 % CI = 1.01-1.25, p = 0.03), additive model (OR = 1.25, 95 % CI = 1.01-1.54, p = 0.04), and recessive model (OR = 1.23, 95 % CI = 1.02-1.49, p = 0.03), whereas no evidence of association was found for dominant model (OR = 1.10, 95 % CI = 0.85-1.42, p = 0.47). For c.454-351A>G mutation, no evidence of association was found for all genetic models. Our meta-analysis suggests that ESR1 c.454-397T>C mutation is significantly associated with increased risk of ischemic stroke, whereas no evidence of association was found for ESR1 c.454-351A>G mutation.

[Role of toll like receptor 4 in low shear stress-induced intimal hyperplasia].

OBJECTIVE: To determine the role of toll like receptor 4 (TLR4) in intimal hyperplasia induced by low shear stress (LSS). METHODS: TLR4(-/-) mice and control mice C57BL/6J were used. Polyethylene cuff was placed on murine carotid to establishing a LSS model. Cultured vascular endothelial cells under LSS condition were used as an in vitro LSS cell model. Intimal hyperplasia was evaluated pathologically. TLR4 was tested by Western blot and the expression of IL-1ß, IL-6 and TNF-α mRNA were detected using RT-PCR. Cell proliferation was determined by detecting DNA synthesis. RESULTS: LSS elicited significant carotid intimal hyperplasia in normal mice but a slight neointima formation in TLR4(-/-) mice (42.67 ± 16.46 vs 7.03 ± 2.95, P < 0.05). LSS upregulated the expression of TLR4 (2.30 ± 0.66 vs 0.16 ± 0.10, P < 0.05), as well as the mRNA of IL-1ß (6.52 ± 3.15 vs 1.65 ± 0.45, P < 0.01), IL-6 (16.17 ± 7.49 vs 6.50 ± 1.84, P < 0.01) and TNF-α(9.98 ± 3.77 vs 2.72 ± 1.03, P < 0.01) in normal mice. However, only moderate increases in IL-6 and TNF-α mRNA were observed in TLR4(-/-) mice. LSS induced the proliferation in cultured endothelial cells. And it was further enhanced by TLR4 overexpression (177 ± 33 vs 83 ± 15, P < 0.05) but attenuated by TLR4 silencing (40 ± 8 vs 83 ± 15, P < 0.05). CONCLUSION: TLR4 plays an important role in LSS-induced intimal hyperplasia. It is likely that LSS induces the proliferation of endothelial cells through TLR4-mediated inflammatory reaction and ultimately promotes intimal hyperplasia.

Association between apolipoprotein E gene polymorphism and the risk of vascular dementia: a meta-analysis.

It remains controversial regarding the association between Apolipoprotein E (ApoE) gene polymorphism and the risk of vascular dementia (VaD). The present meta-analysis was performed to derive a more precise estimation of the relationship. The meta-analysis was performed by searching PubMed, Embase and Web of Science databases. A total of 29 studies included 1763 VaD cases and 4534 controls were identified. The results showed evidence for significant association between ApoE ɛ4 mutation and VaD risk (for ɛ3/ɛ4 vs. ɛ3/ɛ3: OR=1.65, 95% CI=1.40-1.94, p-value<0.00001; for ɛ4/ɛ4 vs. ɛ3/ɛ3: OR=3.17, 95% CI=2.09-4.80, p-value<0.00001; for ɛ4 allele vs. ɛ3 allele: OR=1.72, 95% CI=1.40-2.12, p-value<0.00001). The similar results were obtained in the subgroup analysis based on ethnicity. In summary, the present meta-analysis suggests an association between ApoE ɛ4 mutation and increased risk of VaD. However, due to the small sample size in most of the included studies and the selection bias existed in some studies, the results should be interpreted with caution.

Association between 12p13 SNPs rs11833579/rs12425791 near NINJ2 gene and ischemic stroke in East Asian population: evidence from a meta-analysis.

BACKGROUND: Meta-analysis in European population found no association between rs12425791/rs11833579 and ischemic stroke. Several studies focused on East Asians have evaluated the association between this two SNPs and risk of ischemic stroke, but the results have been inconsistent. The aim of this study was to perform a meta-analysis to investigate a more authentic association between rs12425791 and rs11833579 G>A mutation and ischemic stroke in East Asian population, as well as in Chinese Han population. METHODS: Systematic searches of electronic databases Embase, PubMed, Web of Science, and CBM as well as hand searching of the references of identified articles and the meeting abstracts were performed. Study selection, data abstraction and study quality evaluation were independently conducted in duplicate. Statistical analyses were performed using software Stata 11.0. The pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) were performed. Different effects models were used according to the difference in heterogeneity. Publication bias was tested by Begg's funnel plot and Egger's regression test. RESULTS: A total of 4 publications including 7 studies were involved. For rs12425791, significant association was found in allelic model (OR=1.06, 95%CI=1.00-1.11) and dominant model (OR=1.10, 95%CI=1.03-1.18), whereas no evidence of association was found for additive model (OR=1.04, 95%CI=0.93-1.17) and for recessive model (OR=0.99, 95%CI=0.88-1.10). For rs11833579, no evidence of association was found for all genetic models. In the analysis of Chinese Han population, there is lack of evidence for association of ischemic stroke for both SNPs. CONCLUSIONS: In summary, our meta-analysis suggests that rs12425791 is significantly associated with ischemic stroke in East Asian population but not Chinese Han population, of which A alleles increase the risk of ischemic stroke, whereas no evidence of association was found for rs11833579 in East Asian population as well as Chinese Han population.

Association between paraoxonase 2 Ser311Cys polymorphism and ischemic stroke risk: a meta-analysis involving 5,008 subjects.

Epidemiological studies have evaluated the association between paraoxonase 2 (PON2) Ser311Cys polymorphism and ischemic stroke risk which developed inconsistent conclusions. The aim of this study was to perform a meta-analysis to investigate a more authentic association between PON2 Ser311Cys polymorphism and ischemic stroke. Systematic searches in PUBMED, EMBASE, CBM, and CNKI databases were performed. Data analyses were carried out by Review Manager 5.1.2 and Stata 11.0. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used for additive model (Cys/Cys vs. Ser/Ser), dominant model (Ser/Cys+Cys/Cys vs. Ser/Ser), recessive model (Cys/Cys vs. Ser/Cys+Ser/Ser), and allelic model (Cys allele vs. Ser allele), respectively. Publication bias was analyzed by Begg's funnel plot and Egger's test. A total of 7 studies including 2,046 cases and 2,962 controls were involved. Overall, no significant association was found between PON2 Ser311Cys polymorphism and ischemic stroke risk when all studies were pooled into the meta-analysis (for additive model: OR = 0.87, 95% CI = 0.67-1.14; for dominant model: OR = 1.05, 95% CI = 0.91-1.22; for recessive model: OR = 0.90, 95% CI = 0.77-1.05; and for allelic model: OR = 1.17, 95% CI = 0.86-1.59). In the subgroup analysis by ethnicity, significant association was found among Europeans (for recessive model: OR = 0.83, 95% CI = 0.69-0.99). However, due to the small number of studies included in subgroup analysis, the result for European population should be interpreted cautiously.

PPARγ attenuates intimal hyperplasia by inhibiting TLR4-mediated inflammation in vascular smooth muscle cells.

AIMS: Peroxisome proliferator-activated receptor γ (PPARγ) has been reported to attenuate intimal hyperplasia. This study aimed to test the hypothesis that PPARγ inhibits intimal hyperplasia through suppressing Toll-like receptor 4 (TLR4)-mediated inflammation in vascular smooth muscle cells. METHODS AND RESULTS: TLR4(-/-) mice on a C57BL/6J background were used. Increased TLR4 and pro-inflammatory cytokines were observed in wire-injury-induced carotid neointima and in platelet-derived growth factor (PDGF)-activated vascular smooth muscle cells. The TLR4 deficiency protected the injured carotid from neointimal formation and impaired the cellular proliferation and migration in response to lipopolysaccharide and PDGF. Rosiglitazone attenuated intimal hyperplasia. Overexpression of PPARγ suppressed PDGF-induced proliferation and migration and inhibited TLR4-mediated inflammation in vascular smooth muscle cells, while PPARγ silencing exerted the opposite effect. Lipopolysaccharide counteracted the inhibitory effect of PPARγ on PDGF-induced proliferation and migration. Eritoran suppressed the proliferation and migration induced by PDGF and PPARγ silencing. Vascular smooth muscle cells derived from TLR4(-/-) mice showed impaired proliferation and migration upon PDGF activation and displayed no response to PPARγ manipulation. CONCLUSION: PPARγ inhibits vascular smooth muscle cell proliferation and migration by suppressing TLR4-mediated inflammation and ultimately attenuates intimal hyperplasia after carotid injury.

[Clinical characteristics and risk factors of hemodynamic depression after carotid angioplasty and stenting].

OBJECTIVE: To investigate the carotid angioplasty and stenting (CAS)-induced hemodynamic depression (HD) and its impact on postprocedural complications so as to identify its risk factors. METHODS: The incidence, onset time, duration and severity of HD were observed in 196 CAS patients. The influences of clinical baseline and vascular angiographic characteristics on HD were recorded and the relationship between HD and postprocedural complications was analyzed. Logistic regression analysis was used to identify the independent risk factors of HD. RESULTS: The incidence of HD was 53.1%. Most cases of HD (67.3%) developed within 1 - 16 hours postprocedural. And 55.8% HD lasted for over 24 hours and became relieved within 3 - 16 days post-operation. And 78.9% HD patients required medications for the controls of blood pressure and heart rate. Diabetes, hypertension, smoking, plaque involving carotid bulb, ulcerated plaque and calcified plaque were shown to be associated with HD. Further analysis of logistic regression suggested that diabetes and smoking were two protective factors for HD while plaque involving carotid bulb and calcified plaque two independent risk factors for HD. The HD patients were at an increased risk of neurological and cardiopulmonary complications. CONCLUSION: With a high post-CAS incidence after CAS, HD is associated with postprocedural complications. Lesions involving carotid bulb and calcified plaque are two independent risk factors for HD.

Cerebral ischemia aggravates cognitive impairment in a rat model of Alzheimer's disease.

AIM: Autopsy evidence suggests that the presence of both Alzheimer(')s disease (AD) and cerebral infarction pathology is associated with more severe cognitive impairment than that produced by AD pathology alone. This study aims to investigate the effect of cerebral ischemia on cognitive function in rats with AD constructed by hippocampal injection and to determine its underlying mechanism, which is proposed to be of significance to the treatment of AD. MAIN METHODS: AD was modeled by injection of aggregated Aß(1-40), either alone or followed by hippocampal endothelin-1 injection to mimic cerebral ischemia in hippocampus, into the right dentate gyrus (DG) of rats. The Morris water maze was used to evaluate cognitive function. Aß deposition, neuronal loss and phosphorylated tau expression in hippocampus were examined by Congo red staining, Nissl's staining and immunohistochemistry, respectively. Reactive astrocytes, IL-1ß and TNF-α expressions were measured by immunohistochemistry, in situ hybridization and reverse transcription-polymerase chain reaction. KEY FINDINGS: Compared with rats treated with either Aß or endothelin alone, rats treated with both Aß and endothelin showed more aggravated cognitive impairment and more Aß deposits, neuron loss, phosphorylated tau expression, reactive astrocytes, IL-1ß and TNF-α expressions in hippocampus. SIGNIFICANCE: Hippocampal ischemia aggravates cognitive impairment of AD rats by increasing Aß deposits, neuron loss and tau phosphorylation in hippocampus. The enhanced inflammatory response may be responsible for cerebral ischemia-induced aggravation of cognitive impairment in AD rats. Based on these findings, prevention and treatment of cerebral ischemia may improve clinical symptoms of AD and suppress the progression of AD.

The mechanism and characterization of learning and memory impairment in sleep-deprived mice.

Objectives are to examine the effects of sleep deprivation (SD) on spatial learning and memory in mice, to determine how SD effects the expression of phosphorylated cyclic AMP responsive element binding protein (pCREB) in mouse hippocampus, and to explore the mechanism of influence of sleep deprivation on cognitive function. Twenty, 3-month-old female C57BL/6J mice were randomly assigned into two groups, the sleep deprivation group (SD, n = 10) and control group with normal sleep (CC, n = 10). The mice in SD group were deprived sleep by "gentle touch" for 20 days and then all the mice were subjected for Morris Water Maze test to determine the mean latency of escape (LE). Percentage of time spent in the target quadrant was calculated. Mouse hippocampus pCREB levels were quantified by western blot. Compared with CC group, SD mice had a significantly longer mean LE time (P < 0.05) and spent less time in the target quadrant (P < 0.05). Western blot revealed that hippocampus pCREB levels in the SD group were significantly lower than that in control group (0.71 ± 0.03 vs 0.82 ± 0.06, P < 0.01). The impairment in spatial learning and memory in sleep-deprived animals may be associated with the reduction of pCREB in the hippocampus.

Vascular risk aggravates the progression of Alzheimer's disease in a Chinese cohort.

To investigate whether vascular risk affects the progression of Alzheimer's disease (AD), 415 AD patients aged 65 years old and over without cerebrovascular diseases were enrolled and administered with a structured interview to assess demography, vascular risk factors, and cognitive and functional status at baseline, and 324 AD patients were followed up annually for 5 years. A mixed random effects regression model was used to identify the association between vascular risk, individual vascular risk factors, and the progression of AD. After adjusting for confounding factors, AD patients with vascular risk had faster cognitive and functional decline rates than the subjects without such risk factors. Individual vascular risk factors including hypertension and diabetes mellitus, transient ischemic attack and cerebrovascular accident during the follow-up were independently associated with the progression of AD. Our findings suggest that vascular risk aggravates the progression of AD and may be involved in the etiologic process of AD. As such, control of vascular risk may slow down the progression of AD.