Bioinformatics analysis and identification of genes and molecular pathways involved in Parkinson's disease in patients with mutations in the glucocerebrosidase gene.

Glucocerebrosidase (GBA) mutations occur frequently in Parkinson's disease (PD) patients. This study aims to identify potential crucial genes and pathways associated with GBA mutations in patients with PD and to further analyze new molecular mechanisms related to the occurrence of gene mutations from the perspective of bioinformatics. Gene expression profiles of datasets GSE53424 and GSE99142 were acquired from the Gene Expression Ominibus database. Differentially expressed genes (DEGs) were detected, using the 'limma' package in R, comparing IDI-PD 1 (idiopathic PD patients) and GBA-PD 1 [PD patients with heterozygous GBA mutations (GBA N370S)] group samples. The functions of top modules were assessed using the DAVID, whereas gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed. Protein-protein interaction networks were assembled with Cytoscape software and separated into subnetworks using the Molecular Complex Detection Algorithm. Data from GSE53424 and GSE99142 were also extracted to verify our findings. There were 283 DEGs identified in PD patients heterozygous for GBA mutations. Module analysis revealed that GBA mutations in PD patients were associated with significant pathways, including Calcium signaling pathway, Rap1 signaling pathway and Cytokine-cytokine receptor interaction. Hub genes of the two modules were corticotropin-releasing hormone (CRH) and Melatonin receptor 1B (MTNR1B). The expression of CRH was downregulated, whereas that of MTNR1B was upregulated in PD patients with GBA mutations. The expression of CRH and MTNR1B has diagnostic value for PD patients with heterozygous GBA mutations. Novel DEGs and pathways identified herein might provide new insights into the underlying molecular mechanisms of heterozygous GBA mutations in PD patients.

Reduced Serum Levels of Brain-Derived Neurotrophic Factor Are Related to Mild Cognitive Impairment in Chinese Patients with Type 2 Diabetes Mellitus.

BACKGROUND: Brain-derived neurotrophic factor (BDNF) is involved in obesity, type 2 diabetes mellitus (T2DM), and cognitive dysfunction. The present study sought to assess the role of serum levels of BDNF in the pathophysiological process of mild cognitive impairment (MCI), a preclinical phase of dementia in 715 Chinese patients with T2DM. METHODS: Cross-sectional data were obtained from 715 patients with T2DM recruited from a Chinese diabetes center. Serum levels of BDNF were measured with sandwich enzyme-linked immunosorbent assay. The influence of BDNF on MCI was examined using univariate and multivariate binary logistic regression analyses. RESULTS: In univariate and multivariate logistic regression analyses, for each one-unit increase of BDNF, the unadjusted and adjusted risk of MCI decreased by 9% (OR 0.91; 95% CI 0.88-0.93, p < 0.001) and 6% (0.94; 0.87-0.98, p < 0.001) respectively. In multivariate models comparing the first (Q1), second and third quartiles against the fourth quartile of BDNF, BDNF in Q1 and Q2 were associated with MCI, and increased risk of MCI by 275% (OR 3.75; 95% CI 2.38-6.03) and 155% (2.55; 1.32-4.02). These results suggested that for each 1 ng/mL increase of serum level of BDNF, the association became stronger among obese diabetic patients (OR 0.91, 95% CI 0.85-0.96; p < 0.001) versus nonobese diabetic patients (OR 0.95, 95% CI 0.86-0.98; p = 0.001). CONCLUSION: The present data demonstrated that reduced serum levels of BDNF were associated with increased risk of MCI and might be useful for identifying diabetic patients at risk of dementia for early prevention strategies.