Abnormal lncRNA CCAT1/microRNA-155/SIRT1 axis promoted inflammatory response and apoptosis of tubular epithelial cells in LPS caused acute kidney injury.

BACKGROUNDS: Acute kidney injury (AKI) is characterized by excessive inflammatory response and apoptosis in tubular epithelial cells. Recent studies suggested that long non-coding RNAs colon cancer-associated transcript-1 (CCAT-1) and microRNA-155 (miR-155) might regulate cell death and inflammation. We aimed to explore the role of CCAT-1/miRNA-155 axis in the AKI. METHODS: LPS was applied to establish in vitro and in vivo models of AKI using HK2 cells and pcDNA-CCAT1 transgenic mice, respectively. Gene overexpression or knockdown were performed through plasmids transfection. Apoptosis were determined by qRT-PCR, western blotting (Fas, FasL, Caspase-3), AnnexinV/PI staining and TUNEL assay. Cytokines were assessed by ELISA. Interaction of CCAT1/miR-155 and miR-155/SIRT1 were detected by dual-luciferase reporter assay. RNA immunoprecipitation (RIP) was also performed to determine CCAT1/miR-155 interaction. Pathological changes of AKI were evaluated using H&E staining, blood urine nitrogen (BUN) and serum creatinine (Cr) detection kits. The degree of renal fibrosis was determined by Masson trichrome stain. RESULTS: LPS administration reduced CCAT1 and SIRT1 expression, but increased miR-155 levels in tubular epithelial cells in vitro. Luciferase assay demonstrated that miR-155 might bind to and regulate CCAT1 and SIRT1. RIP further confirmed the direct interaction of CCAT1 and miR-155. Restoration of CCAT1 attenuated LPS induced inflammation and apoptosis through sequestering miR-155. The anti-inflammation and pro-survival effects of CCAT1 overexpression and miR-155 inhibition were abolished by SIRT1 knockdown, as indicated by the expression of cytokine and apoptotic markers, as well as H&E, BUN and Cr detection. Dysregulated CCAT1/miR-155/SIRT1 pathway regulated disease progression in a murine model of LPS-induced AKI, and NF-κB pathway involved in. CONCLUSION: CCAT1 restoration sequestered miR-155, leading to upregulation of SIRT1 and alleviated LPS induced renal tubular epithelial cell damage in vitro and in vivo.

Diagnostic significance of PLA2R and IgG4 in elderly patients with idiopathic membranous nephropathy / 解放军医学杂志

Objective To evaluate the diagnostic significance of PLA2R and IgG4 in elderly patients with idiopathic membranous nephropathy (IMN).Methods The clinical data were retrospectively analyzed of patients with IMN (49 males and 49 females,aged 66.6 ± 5.4 years) or Non-IMN (57 males and 41 females,aged 67.1 ± 6.5 years) who were admitted in the authors served Department of Nephrology from Apr.2014 to Feb.2016 and accepted renal biopsy.SPSS13.0 was employed to evaluate the sensitivity,specificity and calculate the area under ROC curve (AUC) of serum anti-PLA2R antibody,glomerular PLA2R and IgG1-4 subclasses on diagnosing IMN.Results On diagnosing IMN,the sensitivity and specificity of serum anti-PLA2R antibody were 77.6％ and 89.8％ [AUC=0.869(0.816-0.923)],of glomerular PLA2R were 66.3％ and 94.9％ [AUC=0.805(0.741-0.87)],and of glomerular IgGl-IgG4 were 80.6％ and 78.6％,60.2％ and 83.7％,41.8％ and 84.7％,and 93.9％ and 89.8％,respectively [AUC=0.767(0.696-0.838),0.709(0.635-0.783),0.628(0.549-0.706) and 0.94(0.901-0.978),respectively].As to the combined use of glomerular PLA2R and IgG4 on diagnosing IMN,the sensitivity was 93.9％ when either one of glomerular PLA2R and IgG4 was positive,or the specificity was 96.9％ when both glomerular PLA2R and IgG4 were positive.Conclusion PLA2R and IgG4 can effectively serve the diagnosis of IMN,and the combined use of PLA2R and IgG4 may be better than single indicator alone.