Blood circulating miRNAs as biomarkers of Alzheimer's disease: a systematic review and meta-analysis.

Aim: It is already known that miRNAs can be differentially expressed in Alzheimer's disease (AD). We aimed to evaluate the performance of miRNAs from blood as potential biomarkers for AD. Materials & methods: MEDLINE, PubMed and Embase were searched for studies about peripheral blood miRNAs that could discriminate patients with AD from cognitively normal controls. The data regarding the specificity and sensitivity were extracted. STATA 14.0 was used to analyze the data. Results: Ten studies containing 770 AD and 664 normal controls. The analysis showed that miRNAs presented excellent diagnostic performance and the overall sensitivity was 0.80 (95% CI: 0.75-0.83), specificity was 0.83 (95% CI: 0.78-0.87) and diagnostic odds ratio was 14 (95% CI: 11-19). Subgroup analysis suggested that the Caucasian group and blood group showed a better performance in AD diagnosis and the diagnostic odds ratio was 42 and 34, respectively. Conclusion: This meta-analysis showed that miRNAs may be a promising biomarkers for AD.

Effect of Notch1 gene on remyelination in multiple sclerosis in mouse models of acute demyelination.

This study aims to explore the effects of Notch1 gene on remyelination in multiple sclerosis (MS). A mouse model of acute demyelination was successfully established and the model mice were grouped as cuprizone (CPZ) group, CPZ + small interfering RNA (siRNA)-Notch1 (siNotch1) group, and CPZ + siRNA negative control (NC) group. Meanwhile, another 3 groups (control, control + siNotch1, and control + siRNA NC) were established in normal mice. The changes of weight and maintenance time in rotating drum of mice were observed. Western blot analysis for the protein expressions related to Notch signaling pathway and oligodendrocyte (OL) differentiation in the corpus callosum of the mice. After model establishment, the weight of CPZ-induced demyelinated mice was decreased. During the repair period, the balance ability and movement of the mice was recovered, especially for those injected with siNotch1 plasmid. After model establishment, the number of myelinated axons was decreased. In comparison with the CPZ and CPZ siRNA NC groups, the CPZ + siNotch1 group had a decrease in the number of premature OLs, but increase in mature OLs, and a decrease in oligodendrocyte precursor cells and astrocytes. The expressions of proteins related to Notch signaling pathway, such as HES, Jagged-1 were decreased in the CPZ + siNotch1 group in contrast to the CPZ and CPZ + siRNA groups, but the OL-related transcription factor Sox10 was increased in the CPZ + siNotch1 group than in the CPZ + siRNA NC and CPZ groups, and Id2 was decreased. Our study provided evidence that the inhibition of Notch1 gene could accelerate remyelination in MS.

Protective effects of Progranulin against focal cerebral ischemia-reperfusion injury in rats by suppressing endoplasmic reticulum stress and NF-κB activation in reactive astrocytes.

The aim of this study is to explore the effect progranulin (PGRN) has on endoplasmic reticulum (ER) stress and the NF-κB activation in reactive astrocytes found in rat models with focal cerebral ischemia-reperfusion (I/R) injury. Sprague-Dawley (SD) rats were grouped into the sham, I/R, PGRN-high dose, PGRN-low dose, and negative control (NC) groups. TTC staining was applied in order to detect the cerebral infarction volume, a TUNEL assay to detect the apoptosis rate of neurons, an ELISA to measure MDA, SOD, iNOS, LDH, TNF-α, IL-1ß, IL-6, and IL-10 levels, and both RT-qPCR and western blotting methods in order to detect PGRN, GFAP, GRP78, CHOP, and NF-κB p65 expressions. The astrocytes (AST) cells were then assigned into the normal, I/R, negative control (NC), PGRN-high dose, and PGRN-low dose groups. After completing the transfection process, the proliferative capacity of AST cells was detected by use of the CCK-8 assay. Both the in vivo and in vitro results, in comparison with the I/R and the NC groups, the PGRN-high dose and PGRN-low dose groups both presented a decrease in cerebral infarction volume, apoptosis rate of neurons, MDA, LDH, iNOS, TNF-α, IL-1ß, IL-6 levels, and GFAP, GRP78, CHOP, NF-κB p65 expressions, and an increase in SOD, IL-10, and PGRN levels as well as cell proliferation depending on dosage. Based on our results, we came to the confirmation that PGRN can reduce neuronal apoptosis by mitigating ER stress in the reactive astrocytes as well as downregulating the inflammatory levels by suppressing the NF-κB signaling pathway.

Prognostic significance of PD-L1 expression in patients with gastric cancer in East Asia: a meta-analysis.

The overexpression of programmed cell death-ligand 1(PD-L1) has been observed in gastric cancer (GC). However, whether the expression of PD-L1 in tumor cells or blood serum is associated with the prognosis of patients with GC remains unclear. Therefore, we performed a meta-analysis to evaluate the prognostic significance of PD-L1 expression in GC. Electronic databases were searched systematically. Studies that met the inclusion criteria were included in the meta-analysis. Data concerning the hazard ratio (HR) for overall survival and disease-free survival with a 95% confidence interval (CI) according to the expression status of PD-L1 evaluated by immunohistochemistry or enzyme-linked immunosorbent assay were extracted. The data were analyzed using a random effects model. Subgroup analyses were proposed. Our results showed that eight studies with 950 patients met the inclusion criteria and were included in the meta-analysis. The pooled HR for overall survival indicated that patients with PD-L1-positive expression had significantly shorter survival time compared with the PD-L1-negative group (HR 1.60, 95% CI 1.09-2.36, P=0.012). The pooled HR for disease-free survival demonstrated that the difference between the two groups was not statistically significant (HR 1.02, 95% CI 0.32-3.20, P=0.98). In conclusion, our results indicate that the evaluation of PD-L1 overexpression in GC tissue or blood serum may be useful in the future as a novel prognostic factor.

Lovastatin induces neuroprotection by inhibiting inflammatory cytokines in 6-hydroxydopamine treated microglia cells.

PURPOSE/AIM: This study aims to investigate the impact of lovastatin on neuroinflammation in 6-OHDA-treated microglia cells. MATERIALS AND METHODS: 6-Hydroxydopamine (6-OHDA)-treated microglia cells were used to investigate the neuroprotective nature of lovastatin. After incubation with 6-OHDA and/or lovastatin for 24 h, test kits were used to detect the levels of LDH and glutamate, which were released from PC12 cells exposed to different culture media. The mRNA levels of TNF-α, IL-6 and IL-1ß were determined by RT-PCR and the protein levels were analyzed by Western blot. RESULTS: LDH and glutamate levels in 6-OHDA-incubated PC12 cells increased, when compared with those in the controls, while incubation with lovastatin inhibited this elevation. The expression levels of TNF-α IL-6 and IL-1ß were significantly upregulated after treatment with 6-OHDA. The 6-OHDA-stimulated mRNA and protein levels of TNF-α IL-6 and IL-1ß were reduced by lovastatin. CONCLUSIONS: Our results suggest that Lovastatin is able to induce neuroprotection by inhibiting inflammatory cytokines. The data provide direct evidence of the potential application of lovastatin for the treatment of neuroinflammatory diseases.

Neuroprotective effect of lovastatin by inhibiting NMDA receptor1 in 6-hydroxydopamine treated PC12 cells.

In addition to original role of lowering cholesterol, statins display multiple neuroprotective mechanisms. In this study, 6-Hydroxydopamine (6-OHDA)-treated pheochromocytoma-12 (PC12) cells were used to investigate the neuroprotective nature of lovastatin. After incubation with 6-OHDA and/or lovastatin, test kits were used to detect the levels of LDH and glutamate, which were released from PC12 cells exposed to different culture media. The mRNA levels of TNF-α, and NMDAR1 were determined by RT-PCR and the protein levels were analyzed by western blot. Our results show that lovastatin significantly decreased both the mRNA and the protein levels of TNF-α and NMDAR1. ELISA assays revealed increased lactate dehydrogenase (LDH) and glutamate binding activity in 6-OHDA-lesioned PC12 cells, and this increase could be prevented by lovastatin. Our results suggest that lovastatin induces neuroprotection by inhibiting NMDAR1 and TNF-α. The data provide direct evidence of the potential application of lovastatin for the treatment of parkinson's diseases.

Simvastatin induces neuroprotection in 6-OHDA-lesioned PC12 via the PI3K/AKT/caspase 3 pathway and anti-inflammatory responses.

BACKGROUND: In addition to their original applications for lowering cholesterol, statins display multiple neuroprotective effects. Inflammatory reactions and the PI3K/AKT/caspase 3 pathway are strongly implicated in dopaminergic neuronal death in Parkinson's disease (PD). This study aims to investigate how simvastatin affects 6-hydroxydopamine-lesioned PC12 via regulating PI3K/AKT/caspase 3 and modulating inflammatory mediators. METHODS: 6-hydroxydopamine-treated PC12 cells were used to investigate the neuroprotection of simvastatin, its association with the PI3K/AKT/caspase 3 pathway, and antiinflammatory responses. Dopamine transporters (DAT) and tyrosine hydroxylase (TH) were examined in 6-hydroxydopamine-treated PC12 after simvastatin treatment. RESULTS: Simvastatin-mediated neuroprotection was associated with a robust reduction in the upregulation induced by 6-OHDA of inflammatory mediators including IL-6, COX2, and TNF-α. The downregulated DAT and TH levels in 6-OHDA-lesioned PC12 were restored after simvastatin treatment. Simvastatin reversed 6-OHDA-induced downregulation of PI3K/Akt phosphorylation and attenuated 6-OHDA-induced upregulation of caspase 3 in PC12. Furthermore, the PI3K inhibitor LY294002 pronouncedly abolished the simvastatin-mediated attenuation in caspase 3. CONCLUSIONS: Our results demonstrate that simvastatin provides robust neuroprotection against dopaminergic neurodegeneration, partially via antiinflammatory mechanisms and the PI3K/Akt/caspase 3 pathway. These findings contribute to a better understanding of the critical roles of simvastatin in treating PD and might elucidate the molecular mechanisms of simvastatin effects in PD.