Urinary single-cell sequence analyzes the urinary macrophage in different outcomes of membranous nephropathy

Abstract BACKGROUND AND AIMS Great progresses have been made in the diagnosis and treatment of membranous nephropathy (MN), but some patients still do not respond to the treatment. We performed single-cell sequencing to analyze the urine cells of patients with and without complete remission of MN. Hope to provide some insights for understanding the different outcome of MN. METHOD Urine single-cell RNA sequencing was performed on 12 healthy controls (HC) and 15 patients with MN. The patients were divided into complete remission group (CR, n = 9) and no remission group (NR, n = 6), according to the response to at least 6 months of immunosuppressive treatment. RESULTS (i) Macrophages were the largest group in urine cells; they were 48.02%, 68.96% and 20.95% in the HC, CR and NR group, respectively. (ii) Detecting cell surface markers to tell their origins. The results showed that urinary macrophages expressing FIColin-1 and S100 calcium binding protein A8 were mainly in NC group and CR group, indicating that they were derived from bone marrow and peripheral blood, while the urinary macrophages expressing the regulator of G-protein signaling 1 and HLA-DPA1, mainly in the NR group, were differentiated from intrinsic kidney cells. (iii) There were different characteristics of urinary macrophage in the three groups. In healthy adults, urine macrophages expressed the metallothionein family, indicating that they can regulate anti-inflammatory and proinflammatory functions bidirectionally. In the CR group, the urine macrophages showed strong proinflammatory properties. In the NR group, the urinary macrophages mainly associated with the level of proteinuria and the impaired renal function with poor proinflammation. CONCLUSION Our study firstly delineated urinary cell maps of healthy individuals and the MN patients. Not only in origin but also in function of urine, macrophages were different in the NC, CR and NR group. This might be a significant help to our understanding of membranous nephropathy.