miR-374b-5p suppresses RECK expression and promotes gastric cancer cell invasion and metastasis

AIM:To profile expression of micro RNAs(mi RNAs)in gastric cancer cells and investigate the effect of mi R-374b-5p on gastric cancer cell invasion and metastasis.METHODS:An mi RNA microarray assay was performed to identify mi RNAs differentially expressed in gastric cancer cell lines(MGC-803 and SGC-7901)compared with a normal gastric epithelial cell line.Upregulation of mi R-374b-5p was newly identified and confirmed via quantitative real-time reverse transcriptionPCR(q RT-PCR).MGC-803 cells were transfected with a synthesized anti-mi R-374b-5p sequence or a control vector using Lipofectamine reagent,or treated with transfection reagent alone or phosphate-buffered saline as controls.Rate of transfection was verified after 48 h by q RT-PCR.Cells were then subjected to transwell migration,wound scratch and cell counting kit-8 assays.A bioinformatic analysis to identify mi R-374b-5p target genes was performed using mi Randa,Pic Tar and Target Scan software.A dual luciferase reporter assay was performed to evaluate the influence of mi R-374b-5p on target gene activation,and q RT-PCR and Western blot were used to evaluate the levels of target m RNA and protein following transfection with mi R-374b-5p antisense oligonucleotides.RESULTS:The microarray profiling revealed downregulation of 14(fold change<0.667;P<0.05)and upregulation of 12(fold change>1.50;P<0.05)mi RNAs in MGC-803 and SGC-7901 cells compared with GES-1 controls.The upregulation of mi R-374b-5p(fold change=1.75 and 1.64 in MGC-803 and SGC-7901,respectively;P<0.05)was confirmed by q RT-PCR.Compared with the control groups,the restoration of mi R-374b-5p expression with anti-mi R-374b-5p significantly suppressed the metastasis,invasion and proliferation of MGC-803 cells.The bioinformatic analysis predicted that the 3’untranslated region(UTR)of reversion-inducing cysteine-rich protein with Kazal motif(RECK)contains three mi R-374b-5p target sequences.RECK was verified as a target gene in a dual luciferase reporter assay showing that activation of RECK 3’UTR-pmir GLO was increased by co-transfection with mi R-374b-5p.Finally,transfection of mi R-374b-5p antisense oligonucleotides increased m RNA and protein levels of RECK in MGC-803cells(P<0.05).CONCLUSION:These findings indicate that upregulation of mi R-374b-5p contributes to gastric cancer cell metastasis and invasion through inhibition of RECK expression.

Dopamine Agonists Exert Nurrl-inducing Effect in Peripheral Blood Mononuclear Cells of Patients with Parkinson＇s Disease

Background： Nurrl plays an essential role in the development, survival, and function maintenance ofmidbrain dopaminergic （DA） neurons, and it is a potential target for Parkinson＇s disease （PD）. Nurrl mRNA can be detected in peripheral blood mononuclear cells （PBMCs）, but whether there is any association of altered Nurrl expression in PBMC with the disease and DA drug treatments remains elusive. This study aimed to measure the Nurrl mRNA level in PBMC and evaluate the effect of Nurrl expression by DA agents in vivo and in vitro. Methods： The mRNA levels of Nurrl in PBMC of four subgroups of 362 PD patients and 193 healthy controls （HCs） using real-time polymerase chain reaction were measured. The nonparametric Mann-Whitney U-test and Kruskal-Wallis test were performed to evaluate the differences between PD and HC, as well as the subgroups of PD. Multivariate linear regression analysis was used to evaluate the independent association of Nurrl expression with Hoehn and Yahr scale, age, and drug treatments. Besides, the Nurrl expression in cultured PBMC was measured to determine whether DA agonist pramipexole affects its mRNA level. Results： The relative Nurrl mRNA levels in DA agonists treated subgroup were significant higher than those in recent-onset cases without any anti-PD treatments （de novo） （P 〈 0.001 ） and HC groups （P 〈 0.010）, respectively. Furthermore, the increase in Nurr I mRNA expression was seen in DA agonist and L-dopa group. Multivariate linear regression showed DA agonists, L-dopa, and DA agonists were independent predictors correlated with Nurrl mRNA expression level in PBMC. In vitlv, in the cultured PBMC treated with 10 μmol/L pramipexole, the Nurrl mRNA levels were significantly increased by 99.61%, 71.75%, 73.16% in 2, 4, and 8 h, respectively （P 〈 0.001 ）. Conclusions： DA agonists can induce Nurrl expression in PBMC, and such effect may contribute to DA agonists-mediated neuroprotection on DA neurons.

Dopaminergic neurons show increased low-molecular-mass protein 7 activity induced by 6-hydroxydopamine in vitro and in vivo

Background:Abnormal expression of major histocompatibility complex class I(MHC-I)is increased in dopaminergic(DA)neurons in the substantia nigra(SN)in Parkinson’s disease(PD).Low-molecular-mass protein 7(β5i)is a proteolytic subunit of the immunoproteasome that regulates protein degradation and the MHC pathway in immune cells.Methods:In this study,we investigated the role of β5i in DA neurons using a 6-hydroxydopamine(6-OHDA)model in vitro and vivo.Results:We showed that 6-OHDA upregulatedβ5i expression in DA neurons in a concentration-and time-dependent manner.Inhibition and downregulation ofβ5i induced the expression of glucose-regulated protein(Bip)and exacerbated 6-OHDA neurotoxicity in DA neurons.The inhibition of β5i further promoted the activation of Caspase 3-related pathways induced by 6-OHDA.β5i also activated transporter associated with antigen processing 1(TAP1)and promoted MHC-I expression on DA neurons.Conclusion:Taken together,our data suggest that β5i is activated in DA neurons under 6-OHDA treatment and may play a neuroprotective role in PD.

Association Analysis of Proteasome Subunits and Transporter Associated with Antigen Processing on Chinese Patients with Parkinson＇s Disease

Background： Proteasome subunits （PSMB） and transporter associated with antigen processing （TAP） loci are located in the human leukocyte antigen （HLA） Class I1 region play important roles in immune response and protein degradation in neurodegenerative diseases. This study aimed to explore the association between single nucleotide polymorphisms （SNPs） of PSMB and TAP and Parkinson＇s disease （PD）. Methods： A case-control study was conducted by genotyping SNPs in PSMB8, PSMBg, TAP1, and TAP2 genes in the Chinese population. Subjects included 542 sporadic patients with PD and 674 healthy controls. Nine identified SNPs in PSMB8, PSMBg, TAP1, and TAP2 were genotyped through SNaPshot testing. Results： The stratified analysis ofrs 17587 was specially performed on gender. Data revealed that female patients carry a higher frequency of rsl7587-G/G versus （A/A ＋ G/A） compared with controls. But there was no significant difference with respect to the genotypic frequencies of the SNPs in PSMB8, TAP1, and TAP2 loci in PD patients. Conclusion： Chinese females carrying the rs 17587-G/G genotype in PSMB9 may increase a higher risk for PD, but no linkage was found between other SNPs in HLA Class II region and PD.

Wnt3a protects SH-SY5Y cells against 6-hydroxydopamine toxicity by restoration of mitochondria function

Background:Wnt/β-catenin signal has been reported to exert cytoprotective effects in cellular models of several diseases,including Parkinson’s disease(PD).This study aimed to investigate the neuroprotective effects of actived Wnt/β-catenin signal by Wnt3a on SH-SY5Y cells treated with 6-hydroxydopamine(6-OHDA).Methods:Wnt3a-conditioned medium(Wnt3a-CM)was used to intervene dopaminegic SH-SY5Y cells treated with 6-OHDA.Cell toxicity was determined by cell viability and lactate dehydrogenase leakage(LDH)assay.The mitochondria function was measured by the mitochondrial membrane potential,while oxidative stress was monitored with intracellular reactive oxygen species(ROS).Western blot analysis was used to detect the expression of GSK3β,β-catenin as well as Akt.Results:Our results showed that 100μM 6-OHDA treated for 24 h significantly decreased cell viability and mitochondrial transmembrane potential,reduced the level ofβ-catenin and p-Akt,increased LDH leakage,ROS production and the ratio of p-GSK3β(Tyr216)to p-GSK3β(Ser9).However,Wnt3a-conditioned medium reversing SH-SY5Y cells against 6-OHDA-induced neurotoxicity by reversing these changes.Conclusions:Activating of Wnt/β-catenin pathway by Wnt3a-CM attenuated 6-OHDA-induced neurotoxicity significantly,which related to the inhibition of oxidative stress and maintenance of normal mitochondrial function.

Progress in mechanisms of acetylcholinesterase inhibitors and memantine for the treatment of Alzheimer’s disease

Alzheimer’s disease(AD)is the most common causes of dementia in the elderly.Currently,only two classes of drugs,acetylcholinesterase inhibitors(AChEIs)and memantine are approved.AChEIs ameliorate cognitive and psychiatric symptoms in AD patients through activation of acetylcholine(ACh)receptors by increased synaptic ACh levels and also have protective effects against glutamate neurotoxicity and inflammation,whereas memantine appears to mainly protect against excitotoxicity and neurodegeneration.Herein,we review the pharmacologic properties of the available AChEIs and memantine,and focus on recent progress in the mechanisms of AD in relation to acetylcholinergic and glutamatergic involvement.