Expression and significance of NGAL in MRL/lpr lupus-prone mice / 中华风湿病学杂志

ABSTRACT

Objective To explore the expression and significance of neutrophil gelatinase-associated lipocalin (NGAL) in lupus nephritis (LN) in mice. Methods Female MRL/lpr lupus mice (n=36) were randomly divided into the experimental group and intervention group, and female Kunming mice (n =18) served as controls. Each mice in the intervention group received intraperitoneal injection of 20 μg anti-mice interleukin (IL)-17 antibody. The serum concentrations of NGAL, IL-17,matrix metalloproteinase(MMP)-9 and tissue inhibitor of metalloproteinase (TIMP)-1 were measured by enzyme-linked immunosorbent assay (ELISA). And the protein expressions of NGAL, IL-17, MMP-9 and TIMP-1 in renal tissue were detected by immunohistochemisty. One-factor analysis of variance (ANOVA) or nonparametric rank sum test was used for the comparisons between the three groups. Associations between these factors were analyzed by Pearson′s test. Results The levels of serum NGAL, IL-17, MMP-9 and TIMP-1 in the experimental group were obviously increased as compared to those in the control group and intervention group [NGAL: (30.31±1.22) ng/ml vs (11.36±0.14) ng/ml, (20.09±0.35) ng/ml, F=986.524, P and the serum levels of IL-17, MMP-9 and MMP-9/TIMP-1(r=0.899, 0.789, 0.925, P<0.01). The protein expression of NGAL in renal tissue was positively correlated with IL-17, MMP-9 and MMP-9/TIMP-1 levels (r=0.929, 0.899, 0.723, P<0.01). Conclusion The level of NGAL in the serum and renal tissue is signifi-cantly increased in the MRL/lpr lupus mice. And it is closely correlated with the levels of IL-17 and MMP-9. Our results suggest the potential role of NGAL in the inflammation of lupus nephritis.