Integrated profiling of microRNA expression in membranous nephropathy using high-throughput sequencing technology

The present study analyzed microRNA (miRNA) expression profiles in peripheral blood lymphocyte cells (PBLCs) from patients with membranous nephropathy (MN) and normal controls (NC), in an effort to improve the understanding of the pathogenesis of MN. High-throughput sequencing was performed on 30 MN patients and 30 healthy individuals (NC group). Known and novel miRNAs were analyzed and the results were confirmed by quantitative reverse transcription PCR (qRT-PCR). In total, 326 miRNAs showed a significant difference in expression between the MN and NC groups. This included 286 downregulated miRNAs and 40 upregulated miRNAs. In addition, there were 6 novel miRNAs that presented differential levels of expression between the MN and NC groups. The miRNAs were mapped to the genome, using a short oligonucleotide alignment program (SOAP), to analyze their expression and distribution. Twenty-five percent of the unique miRNAs in the MN group and 52.1% in the NC group were mapped to the genome. One hundred and eight mismatches were identified. Seventy-seven mismatches were detected in a higher proportion of the MN samples, compared with the NC samples. Twenty-five mismatches were detected in a higher proportion of the NC samples than the MN samples. Differential miRNA expression was also detected between 10 randomly selected pair groups, as depicted in a cluster analysis diagram. These data indicate that differential miRNA expression may be involved in the pathogenesis of MN. In addition, the discrepancies between the MN and NC groups, in the mismatched miRNAs that were mapped to the genome, strongly suggest that miRNAs play an important role in the pathogenesis of human disorders. miRNAs may provide a potential breakthrough in the research of MN and may provide a novel biomarker for the diagnosis and treatment of the disease.