Neutrophil gelatinase–associated lipocalin (NGAL) is expressed and secreted by immune cells, hepatocytes, and renal tubular cells in various pathologic states. NGAL exerts bacteriostatic effects, which are explained by its ability to capture and deplete siderophores, small iron-binding molecules that are synthesized by certain bacteria as a means of iron acquisition. Consistently, NGAL deficiency in genetically modified mice leads to an increased growth of bacteria. However, growing evidence suggests effects of the protein beyond fighting microorganisms. NGAL acts as a growth and differentiation factor in multiple cell types, including developing and mature renal epithelia, and some of this activity is enhanced in the presence of siderophore:iron complexes. This has led to the hypothesis that eukaryotes might synthesize siderophore-like molecules that bind NGAL. Accordingly, NGAL-mediated iron shuttling between the extracellular and intracellular spaces may explain some of the biologic activities of the protein. Interest in NGAL has been sparked by the observation that NGAL is massively upregulated after renal tubular injury and may participate in limiting kidney damage. This review summarizes the current knowledge about the dual effects of NGAL as a siderophore:iron-binding protein and as a growth factor and examines the role of these effects in renal injury.

A 44-year-old man presented with complaints of pain and discomfort in his left eye (OS). On examination, he had bare perception of light in OS and had a diffuse pigmented mass lesion in the nasal quadrant of the bulbar conjunctiva, associated with neovascularisation of the iris and iridocyclitis, with no fundus view. Intraocular pressure OS was 40 mm Hg. B-scan ultrasonography OS revealed an intraocular mass with thickened sclerochoroidal complex. A clinical diagnosis of OS ciliochoroidal melanoma with extraocular extension was made. He underwent OS extended enucleation with implant. Histopathological examination confirmed the diagnosis of ciliochoroidal melanoma with tumour extension into the optic nerve posteriorly and the extrascleral tissues anteriorly. There was no evidence of systemic metastasis. Even in a case of non-juxtapapillary uveal melanoma, poor vision and high intraocular pressure are clinical indicators of optic nerve tumour invasion.

Background: Cisplatin is one of the most widely used chemotherapeutic agents, but the risk of nephrotoxicity frequently hinders the use of higher doses to maximize its antineoplastic effects. The lack of early biomarkers has impaired our ability to initiate potential therapeutic or preventive interventions in cisplatin nephrotoxicity in a timely manner. In this study, we have explored the expression and urinary excretion of neutrophil gelatinase-associated lipocalin (NGAL) in a mouse model of cisplatin-induced nephrotoxic injury. Methods: Mice were subjected to intraperitoneal injections of 20 mg/kg (high dose) or 5 mg/kg (low dose) cisplatin. The expression of NGAL was measured in the kidney and urine by Western analysis and immunofluorescence, and compared to changes in serum creatinine and urinary N-acetyl-β-D-glucosaminidase (NAG). Results: Cisplatin resulted in tubule cell necrosis and apoptosis following the high dose, but not the low dose. By Western analysis, NGAL protein was rapidly induced in the kidney within 3 h of high-dose cisplatin. By immunofluorescence, NGAL was induced predominantly in proximal tubule cells in a punctate cytoplasmic distribution, reminiscent of a secreted protein. NGAL was easily detected in the urine by Western analysis within 3 h of cisplatin administration in a dose- and duration-dependent manner. By comparison, changes in urinary NAG or serum creatinine were not evident until 96 h after cisplatin. Using defined concentrations of purified recombinant NGAL, urinary NGAL excretion following cisplatin administration was quantified to be in the 20–80 ng/ml range. Conclusion: The results indicate that NGAL represents an early and quantitative urinary biomarker for cisplatin nephrotoxicity.