Neutrophil gelatinase-associated lipocalin (NGAL) may play a protective role against rats ischemia/reperfusion renal injury via inhibiting tubular epithelial cell apoptosis

Ren Fail. 2013;35(1):143-9. doi: 10.3109/0886022X.2012.741877. Epub 2012 Nov 15.

Abstract

We investigated the protective effect and mechanism of neutrophil gelatinase-associated lipocalin (NGAL) on rats ischemia/reperfusion (I/R) renal injury. Eighteen Sprague-Dawley male rats were randomly divided into three groups. Control group (n = 6) suffered left unilateral nephrectomy, I/R + NS (normal saline) (n = 6) and I/R + NGAL (n = 6) group were subjected to 45 min right renal ischemia/24 h reperfusion after left unilateral nephrectomy. Serum creatinine (Scr) and blood urea nitrogen (Bun) were measured on automatic biochemistry analyzer; kidney sections were stained with hematoxylin-eosin; terminal dUTP nick-labeling method was used to examine the apoptosis of tubular epithelial cells; Cleaved caspase-3 and Bax protein expression were detected by immunohistochemistry and Western Blot; real-time polymerase chain reaction was used to detect the expression of Bax mRNA. Rats with NGAL displayed an attenuated renal damage and a decreased number of tubular epithelial cell apoptosis compared to the I/R + NS group (Scr 63.400 ± 11.908 vs. 121.857 ± 17.151 μmol/L, Bun 14.840 ± 2.868 vs. 28.557 ± 6.434 mmol/L, apoptosis cell number 7.800 ± 1.924 vs. 15.400 ± 3.049/high power field (HPF), p < 0.05), the values were lower in the control group (24.000 ± 3.829 μmol/L, 5.814 ± 1.961 mmol/L, 1.800 ± 0.837/HPF, p < 0.05) compared to two groups above; NGAL-treated rats showed down-regulated Cleaved caspase-3 protein (0.284 ± 0.066 vs. 0.409 ± 0.073, p < 0.05), Bax protein (0.346 ± 0.055 vs. 0.443 ± 0.041, p < 0.05), Bax mRNA (1.423 ± 0.187 vs. 2.550 ± 0.217, p < 0.05) compared to I/R + NS group, but the values were higher in both of the two groups than those in the control group (Cleaved caspase-3 protein 0.104 ± 0.029, Bax protein 0.155 ± 0.027, Bax mRNA 1.000 ± 0.000, p < 0.05). We supposed that exogenous NGAL can inhibit the activation of caspase-3, reduce the expression of Bax, and thus reduce renal tubular cell apoptosis and protect renal function in I/R injury rats.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Kidney Injury / metabolism
  • Acute Kidney Injury / pathology
  • Acute Kidney Injury / prevention & control*
  • Acute-Phase Proteins / administration & dosage*
  • Animals
  • Apoptosis / drug effects*
  • Apoptosis / genetics
  • Blotting, Western
  • Caspase 3 / biosynthesis
  • Caspase 3 / genetics
  • Disease Models, Animal
  • Epithelial Cells / drug effects
  • Epithelial Cells / metabolism
  • Epithelial Cells / pathology
  • Gene Expression Regulation / drug effects
  • Immunohistochemistry
  • In Situ Nick-End Labeling
  • Injections, Intravenous
  • Kidney Tubules / drug effects
  • Kidney Tubules / metabolism*
  • Kidney Tubules / pathology
  • Lipocalin-2
  • Lipocalins / administration & dosage*
  • Male
  • Proto-Oncogene Proteins / administration & dosage*
  • RNA / biosynthesis
  • RNA / genetics
  • Rats
  • Rats, Sprague-Dawley
  • Real-Time Polymerase Chain Reaction
  • Reperfusion Injury / metabolism
  • Reperfusion Injury / pathology
  • Reperfusion Injury / prevention & control*
  • bcl-2-Associated X Protein / biosynthesis
  • bcl-2-Associated X Protein / genetics

Substances

  • Acute-Phase Proteins
  • Lcn2 protein, rat
  • Lipocalin-2
  • Lipocalins
  • Proto-Oncogene Proteins
  • bcl-2-Associated X Protein
  • RNA
  • Caspase 3