Roles of human liver type fatty acid binding protein in kidney disease clarified using hL-FABP chromosomal transgenic mice

Kidney disease develops to renal failure over a period of days, months or years, hence, clinical markers that indicate the real‐time renal pathophysiological conditions is important. Liver type fatty acid binding protein (L‐FABP) is a 14 kDa molecule predominantly expressed in human proximal tubules. Clinical studies demonstrate that urinary excretion of L‐FABP derived from the proximal tubules is an excellent biomarker for predicting and monitoring deterioration of renal function or for early detection of kidney disease. However, in order to clarify the pathophysiological roles or dynamics of renal L‐FABP in diseased settings, in vivo experimental studies of kidney diseases are indispensable. Since L‐FABP is not endogenously expressed in murine kidneys, a transgenic (Tg) mouse model with expression of the human L‐FABP gene was established. This review article summarizes the findings on the pathophysiological roles and dynamics of renal human L‐FABP in the recent experimental studies performed using this Tg mouse model. This article reviews the role of fatty acid binding protein in inflammatory renal diseases. The authors discuss studies using their own transgenic mouse model and recently published work of others.