Neutrophil gelatinase-associated lipocalin protects renal tubular epithelial cell in ischemic/reperfusion injury rats via apoptosis-regulating proteins.

We investigated the role of neutrophil gelatinase-associated lipocalin (NGAL) on renal tubular epithelial cell in the renal ischemia/reperfusion injury (IRI) rats. Male Sprague-Dawley rats were randomly assigned to three groups. The control group (n = 5) underwent left nephrectomy. The ischemia/reperfusion (I/R) + normal saline (NS) (n = 5) and I/R + NGAL groups (n = 5) were subjected to 45 min right renal ischemia followed by 48 h of reperfusion after left nephrectomy. The pathological changes of kidney tissues were investigated using hematoxylin-eosin staining; renal tubular epithelial cell apoptosis was detected using terminal dUTP nick-labeling method; expression of apoptosis-regulating protein Fas and Bcl-2 was measured using real-time polymerase chain reaction, Western blot, and immunohistochemical staining. Compared with I/R + NS group, kidney tissues from I/R + NGAL group revealed reduced histological damage and a decreased number of renal tubular epithelial cell apoptosis (9.2 ± 2.53 nuclei or 4.0 ± 0.7 per high-power field vs. 20.3 ± 3.7 nuclei or 8.1 ± 0.3 per high-power field); rats with NGAL showed downregulated fas mRNA (2.34 ± 0.51 vs. 6.84 ± 2.34), fas protein (0.65 ± 0.05 vs. 0.95 ± 0.08), and upregulated bcl-2 protein (0.33 ± 0.05 vs. 0.24 ± 0.03). The results had statistical significance (p < 0.05). We think NGAL could protect against renal IRI and might be related to decreasing tubular epithelial cell apoptosis via adjusting the expression of apoptosis-regulating proteins.