Yongsheng Yuan

miR-622 suppresses proliferation, invasion and migration by directly targeting activating transcription factor 2 in glioma cells

Abstract Malignant gliomas are the most common and devastating primary brain tumors in adults. The rapid invasion of tumor cells into the adjacent normal brain tissues is a major cause of treatment failure, yet the mechanisms that regulate this process remain poorly understood. MicroRNAs have recently emerged as regulators of invasion and metastasis by acting on multiple signaling pathways. In this study, we found that miR-622 is significantly downregulated in glioma tissues and cell lines. Functional experiments showed that increased miR-622 expression reduced glioma cell invasion and migration, whereas decreased miR-622 expression enhanced cell invasion and migration. Moreover, activating transcription factor 2 (ATF2), an important transcription factor that regulate tumor invasion, was identified as a direct target of miR-622. Knockdown of ATF2 using small interefering RNA recapitulated the anti-invasive function of miR-622, whereas restoring the ATF2 expression attenuated the function of miR-622 in glioma cells. Furthermore, clinical data indicated that miR-622 and ATF2 were inversely expressed in glioma specimens. Our findings provide insight into the specific biological behavior of miR-622 in tumor invasion and migration. Targeting miR-622/ATF2 axis is a novel therapeutic approach for blocking glioma invasion.

Reduced plasma serotonin and 5-hydroxyindoleacetic acid levels in Parkinson's disease are associated with nonmotor symptoms

BACKGROUND Accumulating evidence suggests that serotonergic system may be implicated in the pathophysiology of Parkinsons disease (PD), and particularly in nonmotor symptoms such as depression, fatigue, sleep disorders, sensory and autonomic dysfunction. This study aimed to evaluate plasma levels of serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) in PD patients, and investigate their associations with nonmotor symptoms. METHODS Eighty-two PD patients and sixty-four controls underwent a series of clinical assessments, including Hamilton Depression Scale, Fatigue Severity Scale, Pittsburgh Sleep Quality Index, Visual Analog Scale for Pain, and Scale for Outcomes in PD for Autonomic Symptoms. Plasma 5-HT and 5-HIAA levels were measured by HPLC-ECD. RESULTS PD patients exhibited worse performance on nonmotor symptom scales (all P-values <0.001) and presented lower plasma levels of 5-HT (P < 0.001) and 5-HIAA (P < 0.001) than control individuals. Within the PD group, decreased concentrations of plasma 5-HT and 5-HIAA were correlated with more severe depression (r = -0.447, P < 0.001; r = -0.407, P < 0.001, respectively) and pain (r = -0.485, P < 0.001; r = -0.416, P < 0.001, respectively). After performing multiple linear regression, plasma 5-HT (P = 0.01) and 5-HIAA (P = 0.006) remained significantly associated with depression. CONCLUSIONS Our results suggest that serotonergic dysfunction might exist in PD, and specifically correlated with depression and pain in PD. Plasma levels of 5-HT and 5-HIAA may be considered as peripheral markers for depression in PD.

Change in Plasma Levels of Amino Acid Neurotransmitters and its Correlation with Clinical Heterogeneity in Early Parkinson's Disease Patients

The correlation between plasma amino acid (AA) neurotransmitters and clinical heterogeneity in early patients with Parkinsons disease (PD) is still poorly understood.

Correlations between plasma levels of amino acids and nonmotor symptoms in Parkinson’s disease

Converging evidence suggests that changes in plasma levels of amino acids are involved in Parkinson’s disease (PD), but their roles in nonmotor symptoms (NMS) of PD remain unclear. The aim of this study was to evaluate the correlations between plasma amino acids and NMS of PD. Plasma levels of aspartate (Asp), glutamate (Glu), glycine (Gly) and γ-aminobutyric acid (GABA) were measured in 92 PD patients and 60 healthy controls. Four NMS, including depression, pain, sleep disturbances and autonomic dysfunction were assessed in enrolled subjects using the Hamilton Depression Scale, the short form of the McGill Pain Questionnaire, the Pittsburgh Sleep Quality Index and the Scale for Outcomes in Parkinson’s disease for Autonomic Symptoms, respectively. Hierarchical multiple regression analysis was used to evaluate the correlations between plasma levels of amino acids and NMS. PD patients exhibited significantly higher scores of NMS scales and lower plasma levels of amino acids compared to healthy controls. Within the PD group, plasma levels of Asp and Glu were negatively associated with the severity of depression and sleep disturbances. Moreover, decreased plasma level of GABA was correlated with more severe symptoms of sleep disturbances. After controlling for gender, disease duration, severity of motor symptoms and anti-parkinsonian medications, Glu but not Asp remained significantly associated with depression, along with Asp, GABA but not Glu remained negatively associated with sleep disturbances. The altered plasma levels of amino acids may be implicated in the pathogenesis of NMS of PD.

The association between glycogen synthase kinase 3 beta polymorphisms and Parkinson's disease susceptibility: a meta-analysis.

Previous studies on the association between glycogen synthase kinase 3 beta (GSK3-β) polymorphisms (rs334558 and rs6438552) and Parkinsons disease (PD) susceptibility remained inconsistent. Thus, the goal of this study was to re-examine their exact association by a meta-analysis. All eligible studies were identified by a systematic literature search of multiple databases. Six studies (3105 cases and 4387 controls) on rs334558 and six studies (2579 cases and 4091 controls) on rs6438552 were included. The quality of these studies was generally good according to the Newcastle-Ottawa Scale (NOS). The meta-analysis showed null association between the two variants and PD susceptibility in all genetic models from the overall or Caucasian population. However, the analysis of rs334558 revealed that the risk of PD decreased in heterozygote, dominant or additive models (OR=0.60, 95% CI: 0.48, 0.74; OR=0.63, 95% CI: 0.51, 0.78; OR=0.82, 95% CI: 0.71, 0.94, respectively) from the Eastern Asian population. Moreover, the analysis on the homozygote, heterozygote, dominant or additive models suggested that rs6438552 also reduced the PD risk (OR=0.45, 95% CI: 0.24, 0.84; OR=0.62, 95% CI: 0.39, 0.97; OR=0.57, 95% CI: 0.37, 0.87; OR=0.66, 95% CI: 0.49, 0.88, respectively) in the Eastern Asian population. Together, the findings suggest that the two variants both reduced the risk of PD in the Eastern Asian subgroup but not in the overall and Caucasian populations, which should be cautiously interpreted because of limited number of included studies.

Abnormal Resting-State Neural Activity and Connectivity of Fatigue in Parkinson's Disease

Fatigue is a common burdensome problem in patients with Parkinsons disease (PD), but its pathophysiological mechanisms are poorly understood. This study aimed at investigating the neural substrates of fatigue in patients with PD.

Regional homogeneity alterations differentiate between tremor dominant and postural instability gait difficulty subtypes of Parkinson’s disease

Parkinson’s disease (PD) can be classified into the tremor dominant (TD) subtype and the postural instability gait difficulty (PIGD) subtype, which present with different clinical courses and prognoses. However, the symptom-specific intrinsic neural mechanisms underlying the subtypes of PD still remain elusive. In the current study, we utilized resting-state fMRI (rs-fMRI) combined with the regional homogeneity (ReHo) method to investigate the modulations of neural activity in 13 patients with predominantly PIGD (p-PIGD) and 15 patients with predominantly TD (p-TD) in the resting state. Compared with healthy controls, the p-PIGD and the p-TD groups both displayed ReHo changes in the default mode network (DMN). By contrast, the p-TD group exhibited more ReHo alterations in the cerebellum involved in the cerebello-thalamo-cortical (CTC) loops, whilst the p-PIGD group in extensive cortical and sub-cortical areas, including the frontal, parietal, occipital, temporal, limbic lobes, basal ganglia and thalamus, which are involved in the striatal-thalamo-cortical (STC) loops. Direct comparison between the two groups showed significant ReHo alterations in the primary visual cortex. Our findings underscore the differential involvement of the STC and CTC circuits underlying the two subtypes of PD. Moreover, relatively widespread neural activity abnormality, especially in the motor-related regions as well as the visual network, is apparently a characteristic feature of PIGD symptoms. This study could shed light on the underlying pathophysiology and clinical heterogeneity of PD presentation.

Reduced plasma taurine level in Parkinson's disease: association with motor severity and levodopa treatment.

Purpose: This study aimed to evaluate the level of taurine in plasma, and its association with the severity of motor and non-motor symptoms (NMS) and chronic levodopa treatment in Parkinsons disease (PD). Patients and methods: Plasma taurine level was measured in treated PD (tPD), untreated PD (ntPD) and control groups. Motor symptoms and NMS were assessed using the Unified Parkinsons Disease Rating Scale, the short form of the McGill Pain Questionnaire, the Hamilton Depression Scale, the Scale for Outcomes in Parkinsons disease for Autonomic Symptoms and the Pittsburgh Sleep Quality Index. Longtime exposure to levodopa was indicated by its approximate cumulative dosage. Results: The plasma taurine levels of PD patients were decreased when compared with controls and negatively associated with motor severity but not NMS. Moreover, tPD patients exhibited lower levels of plasma taurine than ntPD patients. Interestingly, plasma taurine levels negatively correlated with cumulative levodopa dosage in tPD. After controlling for potential confounders, the association between taurine and levodopa remained significant. Conclusion: Our study supports that taurine may play important roles in the pathophysiology of PD and the disturbances caused by chronic levodopa administration.

The Neural Basis of Postural Instability Gait Disorder Subtype of Parkinson's Disease: A PET and fMRI Study

The aim of this study is to further uncover the neural basis of postural instability gait disorder (PIGD) subtype of Parkinsons disease.

Alterations in regional homogeneity of resting-state brain activity in fatigue of Parkinson’s disease

Fatigue is a common complaint in patients with Parkinson’s disease (PD). However, the neural bases of fatigue in PD remain uncertain. In this cross-sectional study, our aim was to study the change of the local brain function in PD patients with fatigue. Among 49 patients with PD, 17 of them had fatigue and the remaining 32 patients without fatigue, and 25 age- and gender-matched healthy controls were enrolled. All subjects were evaluated with Fatigue Severity Scale (FSS) and had a resting-state functional magnetic resonance imaging (rs-fMRI) scan. The fMRI images were analyzed using regional homogeneity (ReHo) to study the change of the local brain function. ReHo analysis controlling for gray matter volume, age, gender, and education showed decreased ReHo in the left anterior cingulate cortex (ACC) and the right superior frontal gyrus (dorsolateral part), and increased ReHo in the left postcentral gyrus and the right inferior frontal gyrus (orbital and triangular part), compared PD-F with PD-NF; In PD patients, the regional activity in the left ACC and the right superior frontal gyrus (dorsolateral part) was negatively correlated with the FSS scores, while that in the left postcentral gyrus, the right inferior frontal gyrus (orbital and triangular part) was positively correlated with the FSS scores. This study demonstrates that brain areas including frontal, postcentral and ACC regions indicative of sensory, motor, and cognitive systems are involved in fatigue in PD patients.