P0530A NOVEL LNCRNA(LRAN9884) PROMOTES AKI VIA MAINTAINING MINCLE-DEPENDENT M1 MACROPHAGE PHENOTYPE

Abstract

Abstract Background and Aims Macrophages are key inflammatory cells and play a critical role in renal inflammation in acute kidney injury (AKI). M1 inflammatory macrophage and M2 anti-inflammatory macrophage act reverse role. Phenotype of macrophages is highly flexible and can be changed over time. However, the underlying mechanism of M1 and M2 macrophage phenotype switching during AKI is still largely unclear. In our previous study, we identified a novel lncRNA (LRNA9884) might contribute to inflammation according to modifying macrophages. The present study was designed to uncover the pathogenic role and the underlying mechanism of LRNA9884 in cisplatin-induced AKI. Method Expression level and pattern of LRNA9884 were examined in cisplatin-induced AKI mice. The regulatory mechanisms of LRNA9884 was investigated in cultured bone marrow–derived macrophages (BMDMs) in vitro by silencing or overexpressing of LRNA9884. Flow Cytometer, fluorescence in situ hybridization (FISH) and other multiple molecular biological techniques were applied to figure out the role of LRNA9884 under acute kidney injury. Results LRNA9884 was significantly upregulated in the kidney of cisplatin-induced mice and was associated with the progression of the renal inflammation by using RT-PCR and ISH assay. FISH assay with immunofluorescence co-staining detected that LRNA9884 was largely expressed in the nucleus of macrophage in cisplatin-induced mice kidney compared with the sham group at day 1 after AKI injury. LRNA9884 was remarkedly induced by TNF-α (10ng/ml) in BMDMs as time- and dose- dependent. Western blot and RT-PCR showed that silencing of LRNA9884 effectively inhibited upregulated of macrophage-inducible C-type lectin (Mincle) and iNOS induced by TNF-α. More importantly, we identified that LRNA9884 maintained M1 macrophages phenotype by triggering mincle production at transcriptional level as evidenced by ChIP assay. Conclusion LRNA9884 is a mincle-dependent lncRNA that highly-expressed in macrophages under AKI development. Targeting of LRNA9884 effectively blocked the inflammatory response via promoting the transition M1 macrophage to M2 macrophage phenotype. This study will shed new lights on the understanding of pathological role of novel LRNA9884 in AKI.