The pathophysiological significance between autosomal dominant polycystic kidney disease and neutrophil gelatinase-associated lipocalin

Autosomal dominant polycystic kidney disease (ADPKD) is the most common form of polycystic kidney disease (PKD) and is a typical adult-onset multisystem disorder. It is a progressive disease characterized by the disruption of renal tubular integrity, involving the modulation of cellular proliferation and apoptosis. Most ADPKD results from a mutation in either the PKD1 or PKD2 gene encoding polycystin-1 and polycystin-2, respectively. With the inconsistent disease course of ADPKD, biomarkers that can predict the treatment efficacy and rapid progression of the disease are needed. Studies have identified neutrophil gelatinase-associated lipocalin (NGAL) as a biomarker for predicting the progression of ADPKD patients. The NGAL protein is expressed at a low level in the kidneys, which helps to regulate iron transport and participates in epithelial differentiation, inflammation, and cell proliferation. NGAL level also increases in serum and urine during renal detrimental conditions such as ischemia and acute and chronic kidney diseases. On the other hand, some studies have also demonstrated that NGAL may act as a tubulogenic factor controlling cell growth and that the upregulation of the Ngal gene hinders tubular cell proliferation, resulting in significantly reduced cyst growth in cellular and murine models of ADPKD. This review attempts to correlate ADPKD and NGAL based on available research findings to evaluate the therapeutic potential of NGAL in ADPKD.