Landscape of infiltrating immune cells and related genes in diabetic kidney disease

IntroductionDiabetic kidney disease (DKD) is one of the prominent microvascular complications of diabetes and the leading cause of end-stage renal disease. Inflammation plays a crucial role in the development and progression of DKD. Currently, only a few studies depict the landscape of infiltrating immune cells and their potential regulatory network in DKD. To gain a better understanding of the role of immune cells in the renal microenvironment, we sought to reveal the profile of infiltrating immune cells and their potential regulatory network in DKD.MethodsWe obtained the transcriptomes and the corresponding clinical data of 19 DKD and 25 control samples from the Gene Expression Omnibus and Nephroseq databases, respectively. Thereafter, we conducted an analysis on the infiltrating immune cells and identified immune-related differentially expressed genes through bioinformatics. Finally, correlation analyses among immune cells, immune genes, and clinical manifestations were performed, and differentially infiltrating immune cell subsets were verified through multiplex immunofluorescence staining.ResultsWe demonstrated the landscape of infiltrating immune cells in patients with DKD and identified the top five hub immune regulatory genes (C3, IL7R, TYROBP, BMP2, and CXCL6). Three of the core genes (C3, BMP2, and CXCL6) were significantly correlated with the estimated glomerular filtration rate. Through multiplex immunofluorescence staining, we verified that macrophage numbers were remarkably elevated, whereas Treg cells were remarkably reduced in diabetic kidney tissues. Th2 cells were scarce in the kidney tissue.ConclusionCollectively, our findings shed light on new, possible therapeutic strategies for DKD, from an immune microenvironment perspective.