| Objective IgA nephropathy is the most common primary glomerular disease in China,and also the most important cause of young and middle-aged patients entering the uremia stage,bringing a heavy burden to the country and patients' families.Therefore,it is particularly important to clarify the pathogenesis of IgA nephropathy and propose targeted treatment methods.At present,gene chip technology has been widely used in biomedical research,providing important technical support for clarifying gene regulation mechanism of various diseases and developing targeted treatment programs.Several large studies have confirmed the existence of multiple differentially expressed genes in patients with IgA nephropathy using gene chip technology,but the differentially expressed genes and pathways occurred in studies are different.Therefore,our study aims to extract mRNA from Gene Expression Omnibus database in IgA nephropathy patients and synthesize the microarray data of differentially expressed genes.At the same time,our study also conducted clinical detection to verify the abnormal expression profile of mRNA gene extracted from B lymphocytes in peripheral blood of patients with IgA nephropathy,and to explore the correlation between Gd-IgA1 molecular level and the differentially expressed gene.Method Three studies were selected from Gene Expression Omnibus(GEO)database according to the diagnostic criteria of IgA nephropathy.We merged different series data after processing the original data using robust multiple chip average algorithm(RMA),and eliminated the batch effect with the method of ComBat.Finally the data was analyzed using R language v3.2.2.The biological significance of differentially expressed Genes were analyzed using Gene Ontology set(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG).For validation of microarray data analysis results,our study enrolled 5 patients with IgA nephropathy and 3 healthy volunteers,and KM55 kit were used to detect the plasma in the Gd-IgA1 molecular level.We separated B lymphocytes from peripheral blood then extracted mRNA which was prepared for reverse transcription-polymerase chain reaction(PT-PCR).Finally we verified the differentially expressed genes,and used Person analysis method to analyze the correlation between differentially expressed genes and the level of Gd-IgA1.Results The mRNA microarray data analysis of three studies on IgA nephropathy showed that 655 genes were differentially expressed(p < 0.05),319 genes were up-regulated and 336 genes were down-regulated.It showed that these dysregulation mRNA genes are mainly related to pentose-phosphate shunt,non-oxidative branch,and leukocyte activation,protein kinase binding,focal adhesion according and so on to GO analyses.Meanwhile,it revealed that the pathways enriched in intestinal immune network for IgA production,autophagy-animal and mitophagy-animal and so on according to KEGG pathway analysis.And the validation results showed that there were 77 differentially expressed genes which were the same of genes in the above three microarray data series.Among them,eight were associated with Gd-IgA1 molecular level,including tumor suppressor gene PTEN gene(gene of phosphate and recogniton homology does on chromsome ten).PTEN had the strongest correlation with Gd-IgA1 level(r =-0.83,P = 0.01).Conclusion Microarray data analysis showed that intestinal mucosal immunity,tumor immunity and autophagy may be involved in the occurrence of IgA nephropathy.The results of further experimental verification suggested that the decreased level of tumor suppressor gene PTEN might mediate the production of gd-iga1 molecule in patients with IgA nephropathy. |
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