BACKGROUND Liver-type fatty acid-binding protein (L-FABP) is a biomarker for early detection of renal disease in humans. Liver-type fatty acid-binding protein is cytotoxic oxidation products secreted from proximal tubules under ischemia and oxidative stress. OBJECTIVE To examine renal expression and quantify urinary excretion of L-FABP in catswith renal disease. ANIMALS One hundred and thirty-four client-owned cats including 34 cats with serum creatinine (sCre) values >1.6 mg/dL and 10 other cats that died in clinics. METHODS Tissue expressions of L-FABP were examined by reverse transcription polymerase chain reaction and Western blotting. Urinary L-FABP (uL-FABP) and serum L-FABP (sL-FABP) levels were determined by enzyme-linked immunosorbent assay. Anti-liver-type fatty acid-binding protein antibody immunostained renal sections. RESULTS Feline kidneys express L-FABP. Strong L-FABP signals were observed in the lumens of proximal tubular cells in 5 cats with high uL-FABP excretion, but not in 5 cats with low uL-FABP excretion. In 9 normal cats, uL-FABP index was <1.2 μg/g urinary creatinine (uCre). High uL-FABP indexes (>10.0 μg/g uCre) were detected in 7 of 100 cats with low sCre (<1.6 mg/dL) and 18 of 44 cats with high sCre (>1.6 mg/dL). There was a weak correlation between L-FABP index and sCre, serum symmetric dimethylarginine (SDMA), or blood urea nitrogen (BUN), and these correlation coefficients were increased by analyzing only data of cats with sCre >1.6 mg/dL. There was a weak correlation between u L-FABP index and sL-FABP in all tested cats, but not in cats with high sCre. CONCLUSIONS AND CLINICAL IMPORTANCE This study demonstrates correlations between L-FABP and current renal biomarkers for chronic kidney disease in cats, such as sCre and SDMA. Liver-type fatty acid-binding protein may be a potential biomarker to predict early pathophysiological events in feline kidneys.

中文翻译：

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患有肾脏疾病的猫的肾脏表达和肝型脂肪酸结合蛋白的尿排泄。

背景技术肝型脂肪酸结合蛋白（L-FABP）是用于早期发现人类肾脏疾病的生物标记。肝脏型脂肪酸结合蛋白是在缺血和氧化应激下从近端小管分泌的细胞毒性氧化产物。目的探讨肾病猫的肾脏表达并定量分析L-FABP的尿排泄。动物一百三十四只客户拥有的猫，包括三只血清肌酐（sCre）值> 1.6 mg / dL的猫和十只在诊所死亡的猫。方法通过逆转录聚合酶链反应和蛋白质印迹法检测L-FABP的组织表达。尿L-FABP（uL-FABP）和血清L-FABP（sL-FABP）水平通过酶联免疫吸附法测定。抗肝型脂肪酸结合蛋白抗体免疫染色的肾脏切片。结果猫肾表达L-FABP。在高uL-FABP排泄的5只猫的近端肾小管腔中观察到强L-FABP信号，但在低uL-FABP排泄的5只猫中未观察到强L-FABP信号。在9只正常猫中，uL-FABP指数<1.2μg/ g尿肌酐（uCre）。在100只sCre低（<1.6 mg / dL）的猫中有7只和44张高sCre（> 1.6 mg / dL）的猫中有18只检测到高uL-FABP指数（> 10.0μg/ g uCre）。L-FABP指数与sCre，血清对称二甲基精氨酸（SDMA）或血尿素氮（BUN）之间的相关性较弱，仅通过分析sCre> 1.6 mg / dL的猫的数据，这些相关系数会增加。在所有接受测试的猫中，u L-FABP指数与sL-FABP之间的相关性较弱，但在高sCre的猫中并非如此。结论与临床意义这项研究证明了L-FABP与目前猫慢性肾脏疾病的肾脏生物标志物（如sCre和SDMA）之间的相关性。肝型脂肪酸结合蛋白可能是预测猫肾早期病理生理事件的潜在生物标志物。