Long non-coding RNA CCAT1 promotes glioma cell proliferation via inhibiting microRNA-410.

BACKGROUND AND AIM: Long non-coding RNAs have been confirmed to play a critical role in various cancers. In the present study, the effect of long non-coding RNA (lncRNA) CCAT1 on glioma cell proliferation and its potential mechanism were investigated. METHODS AND RESULTS: Real-time PCR results showed that lncRNA-CCAT1 expression was significantly upregulated in glioma cancer tissues and cell lines compared with controls. After inhibiting CCAT1 expression in glioma cell line U251 with siRNA-CCAT1 (si-CCAT1), the cell viability and cell colony formation were decreased, the cell cycle was arrested in G1 phase, and the cell apoptosis was increased. As reported in bioinformatics software starbase2.0, a total of 22 microRNAs were potentially targeted by CCAT1. It was confirmed that miR-410 was altered most by si-CCAT1. After up-regulating CCAT1 expression in U251 cells, miR-410 level was decreased. Luciferase reporter assay confirmed that CCAT1 targeted miR-410. Correlation analysis showed that CCAT1 expression was negatively related to miR-410 expression in glioma cancer tissues. In addition, down-regulation of miR-410 reversed the inhibitory effect of si-CCAT1 on glioma proliferation. CONCLUSION: These data demonstrated that lncRNA-CCAT1 promoted glioma cell proliferation via inhibiting miR-410, providing a new insight about the pathogenesis of glioma proliferation.

Beta-asarone protects against MPTP-induced Parkinson's disease via regulating long non-coding RNA MALAT1 and inhibiting α-synuclein protein expression.

OBJECTIVE: Numerous long non-coding RNAs (lncRNA) have been identified in neurodegenerative disorders including Parkinson's disease (PD). Emerging evidence demonstrates that ß-asarone functions as neuroprotective effects in both in vitro and in vivo models. However, the role of ß-asarone and its potential mechanism in PD remain not completely clear. METHODS: MPTP-induced PD mouse model and SH-SY5Y cells subjected to MPP+ as its in vitro model were used to evaluate the effects of ß-asarone on PD. LncRNA MALAT1 and α-synuclein expression were determined by real-time PCR and western blot methods. RESULTS: ß-Asarone significantly increased the TH+ cells number and decreased the expression levels of MALAT1 and α-synuclein in midbrain tissue of PD mice. RNA pull-down and immunoprecipitation assays confirmed that MALAT1 associated with α-synuclein, leading to the increased stability of α-synuclein and its expression in SH-SY5Y cells. ß-asarone elevated the viability of cells exposed to MPP+. Either overexpressed MALAT1 or α-synuclein could canceled the protective effect of ß-asarone on cell viability. In PD mice, pcDNA-MALAT1 also decreased the TH+ cells number and increased the α-synuclein expression in PD mice with treatment of ß-asarone. CONCLUSION: ß-Asarone functions as a neuroprotective effect in both in vivo and in vitro models of PD via regulating MALAT1 and α-synuclein expression.

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 II 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, PSMB9, TAP1, and TAP2 genes in the Chinese population. Subjects included 542 sporadic patients with PD and 674 healthy controls. Nine identified SNPs in PSMB8, PSMB9, TAP1, and TAP2 were genotyped through SNaPshot testing. RESULTS: The stratified analysis of rs17587 was specially performed on gender. Data revealed that female patients carry a higher frequency of rs17587-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 rs17587-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.

MicroRNA-214 participates in the neuroprotective effect of Resveratrol via inhibiting α-synuclein expression in MPTP-induced Parkinson's disease mouse.

BACKGROUNDS AND AIMS: MicroRNAs (miRNAs) have been reported to be involved in degenerative disorders including Parkinson's disease (PD). α-synuclein expression is strong associated with the pathogenesis of PD. In the present study, we investigated whether the regulation of α-synuclein expression by miR-214 is the potential mechanism underlying the neuroprotective effect of Resveratrol. METHODS: The PD mouse model was established with the injection of MPTP (1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine) and the human neuroblastoma cell line, SH-SY5Y, was administrated with MPP+. RESULTS: The midbrain of PD mice and MPP+ treated SH-SY5Y cells had the lower expression levels of miR-214 and higher mRNA and protein expression of α-synuclein, which were reversed by Resveratrol administration. MiR-214 mimic down-regulated expression of α-synuclein and its 3'-UTR activity, while the levels were up-regulated by miR-214 inhibitor. In addition, the cell viability, elevated by Resveratrol, was also decreased by miR-214 inhibitor or overexpressed α-synuclein. In vivo, miR-214 inhibitor down-regulated TH+ cells of ipsilateral and up-regulated α-synuclein expression compared with the group treated with Resveratrol. CONCLUSION: The loss of miR-214 in PD resulted in the increase of α-synuclein expression, which was the potential mechanism underlying the neuroprotective effects of Resveratrol.

Dopamine Agonists Exert Nurr1-inducing Effect in Peripheral Blood Mononuclear Cells of Patients with Parkinson's Disease.

BACKGROUND: Nurr1 plays an essential role in the development, survival, and function maintenance of midbrain dopaminergic (DA) neurons, and it is a potential target for Parkinson's disease (PD). Nurr1 mRNA can be detected in peripheral blood mononuclear cells (PBMCs), but whether there is any association of altered Nurr1 expression in PBMC with the disease and DA drug treatments remains elusive. This study aimed to measure the Nurr1 mRNA level in PBMC and evaluate the effect of Nurr1 expression by DA agents in vivo and in vitro. METHODS: The mRNA levels of Nurr1 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 Nurr1 expression with Hoehn and Yahr scale, age, and drug treatments. Besides, the Nurr1 expression in cultured PBMC was measured to determine whether DA agonist pramipexole affects its mRNA level. RESULTS: The relative Nurr1 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 Nurr1 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 Nurr1 mRNA expression level in PBMC. In vitro, in the cultured PBMC treated with 10 µmol/L pramipexole, the Nurr1 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 Nurr1 expression in PBMC, and such effect may contribute to DA agonists-mediated neuroprotection on DA neurons.

TGF-ß induced miR-132 enhances the activation of TGF-ß signaling through inhibiting SMAD7 expression in glioma cells.

Transforming growth factors ß (TGF-ß) pathway has been proven to play important roles in oncogenesis and angiogenesis of gliomas. MiR-132 might be related to TGF-ß signaling pathway and high miR-132 expression was reported to be a biomarker of poor prognosis in patients diagnosed with glioma. However, the expression regulation way involved in TGF-ß pathway and clinical significance of miR-132 have not been investigated in glioma cells. Here we reported that the mRNA level of miR-132 and TGF-ß concentration were both increased in patients with brain glioma. Correlation analysis revealed that TGF-ß concentration was positively correlated with mRNA level of miR-132. In addition, the mRNA level of miR-132 was up-regulated by TGF-ß in a concentration-dependent and time-dependent manner. Furthermore, we found that miR-132 was involved in modulation of the TGF-ß signaling pathway and down-regulation of SMAD7 expression by directly targeting the SMAD7 3'-UTR. MiR-132 was negatively correlated with SMAD7 in patients with brain glioma. Taken together, our results suggest that miR-132 could be stimulated by TGF-ß and might enhance the activation of TGF-ß signaling through inhibiting SMAD7 expression in glioma cells. These findings contribute to a better understanding of the mechanism of the activation of TGF-ß signaling by miR-132.

Association of serum uric acid levels with the progression of Parkinson's disease in Chinese patients.

BACKGROUND: Uric acid (UA) is suspected to play a neuro-protective role in Parkinson's disease (PD). This study aimed to evaluate whether the serum UA level was associated with the disease progression of PD in a relatively large population of Chinese patients. METHODS: Serum UA levels were measured from 411 Chinese PD patients and 396 age-matched controls; following the uric acid colorimetric method, the serum creatinine (Scr) levels were also measured to reduce the bias caused by possible differences in renal excretion function. The disease progression was scored by Hoehn and Yahr (H&Y) scales and disease durations; PD group was divided into 3 subgroups according to H&Y scales. Independent-samples t test was performed to analyze the differences between PD group and control group. Multiple analysis of covariance was performed to analyze the differences between PD subgroups. Spearman rank-correlation was performed to evaluate the associations between serum UA or Scr level and disease progression. RESULTS: PD patients were found to have significantly lower levels of serum UA than controls ((243.38 ± 78.91) vs. (282.97 ± 90.80) µmol/L, P < 0.01). As the disease progression, the serum UA levels were gradually reduced. There was a significantly inverse correlation of UA levels with H&Y scales (Rs = -0.429, P < 0.01) and disease duration (Rs = -0.284, P < 0.01) in PD patients of both females and males. No significant difference of the Scr level between PD patients and controls was found ((70.01 ± 14.70) vs. (69.84 ± 16.46) µmol/L), and the Scr level was not involved in disease progression. CONCLUSION: Lower serum UA levels may possess a higher risk of PD, which may be a potential useful biomarker to indicate the progression of PD.