Distal Axonal Proteins and Their Related MiRNAs in Cultured Cortical Neurons
MOLECULAR NEUROBIOLOGY
Authors: Li, Chao; Zhang, Yi; Levin, Albert M.; Fan, Bao Yan; Teng, Hua; Ghannam, Moleca M.; Chopp, Michael; Zhang, Zheng Gang
Abstract
Proteins and microRNAs (miRNAs) within the axon locally regulate axonal development. However, protein profiles of distal axons of cortical neurons have not been fully investigated. In particular, networks of genes encoding axonal proteins and their related miRNAs in sub compartments of neurons such as axons remain unknown. Using embryonic cortical neurons cultured in a microfluidic device and proteomic approaches, we found that distal axons contain 883 proteins. Bioinformatics analysis revealed that 94 out of these 883 proteins are related to regulating axonal growth. Of the 94 genes encoding these proteins, there were 56 candidate genes that can be putatively targeted by axon-enriched 62 miRNAs with 8mer sites that exactly match these target genes. Among them, we validated 11 proteins and 11 miRNAs, by means of western blot and RT-PCR, respectively. Treatment of distal axons with chondroitin sulfate proteoglycans (CSPGs) that inhibit axonal growth elevated miR-133b, -203a, -29a, and -92a, which were associated with reduced protein level of AKT, MTOR, PI3K, DPYSL2, MAP1B, and PPP2CA. In contrast, reduction of miR-128, -15b, -195, -26b, -34b, -376b, and -381 by CSPGs was accompanied by increased EZR, KIF5A, DCX, GSK3B, and ROCK2 proteins. In silico pathway analysis revealed an interconnected network of these miRNAs and protein coding genes that is highly related to regulating axonal growth. Our data provide new insights into networks of miRNAs and their related proteins in distal axons in mediating axonal growth.
Multiple variants in 5q31.1 are associated with systemic lupus erythematosus susceptibility and subphenotypes in the Han Chinese population
BRITISH JOURNAL OF DERMATOLOGY
Authors: Wen, L. L.; Zhu, Z. W.; Yang, C.; Liu, L.; Zuo, X. B.; Morris, D. L.; Dou, J. F.; Ye, L.; Cheng, Y. Y.; Guo, H. M.; Huang, H. Q.; Lin, Y.; Zhu, C. H.; Tang, L. L.; Chen, M. Y.; Zhou, Y.; Ding, Y. T.; Liang, B.; Zhou, F. S.; Gao, J. P.; Tang, X. F.; Zheng, X. D.; Wang, W. J.; Yin, X. Y.; Tang, H. Y.; Sun, L. D.; Yang, S.; Zhang, X. J.; Sheng, Y. J.; Cui, Y.
Abstract
Background A previous study provided evidence for a genetic association between PPP2CA on 5q31.1 and systemic lupus erythematosus (SLE) across multi-ancestral cohorts, but failed to find significant evidence for an association in the Han Chinese population. Objectives To explore the association between this locus and SLE using data from our previously published genome-wide association study (GWAS). Methods Single-nucleotide polymorphisms (SNPs) rs7726414 and rs244689 (near TCF7 and PPP2CA in 5q31.1) were selected as candidate independent associations from a large-scale study in a Han Chinese population consisting of 1047 cases and 1205 controls. Subsequently, 3509 cases and 8246 controls were genotyped in two further replication studies. We then investigated the SNPs' associations with SLE subphenotypes and gene expression in peripheral blood mononuclear cells. Results Highly significant associations with SLE in the Han Chinese population were detected for SNPs rs7726414 and rs244689 by combining the genotype data from our previous GWAS and two independent replication cohorts. Further conditional analyses indicated that these two SNPs contribute to disease susceptibility independently. A significant association with SLE, age at diagnosis < 20 years, was found for rs7726414 (P = 0.001). The expression levels of TCF7 and PPP2CA messenger RNA in patients with SLE were significantly decreased compared with those in healthy controls. Conclusions This study found evidence for multiple associations with SLE in 5q31.1 at genome-wide levels of significance for the first time in a Han Chinese population, in a combined genotype dataset. These findings suggest that variants in the 5q31.1 locus not only provide novel insights into the genetic architecture of SLE, but also contribute to the complex subphenotypes of SLE.