Faculty of Agriculture, Cooperative Department of Veterinary Clinical Medicine, Iwate University, Morioka, Iwate, Japan.
CMIC Holdings Co., Ltd, Tokyo, Japan.
J Vet Intern Med. 2020 Mar;34(2):761-769. doi: 10.1111/jvim.15721. Epub 2020 Feb 22.
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.
To examine renal expression and quantify urinary excretion of L-FABP in catswith renal disease.
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.
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.
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.
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.
肝型脂肪酸结合蛋白（L-FABP）是人类早期发现肾脏疾病的生物标志物。在缺血和氧化应激下，L-FABP 是从近端肾小管分泌的细胞毒性氧化产物。
检测患有肾脏疾病的猫的肾脏组织中 L-FABP 的表达并定量其尿排泄。
134 只患宠猫，包括 34 只血清肌酐（sCre）值>1.6mg/dL 的猫和 10 只在诊所死亡的猫。
通过逆转录聚合酶链反应和 Western blot 检测 L-FABP 的组织表达。通过酶联免疫吸附试验测定尿液 L-FABP（uL-FABP）和血清 L-FABP（sL-FABP）水平。用抗 L-FABP 抗体对肾脏切片进行免疫染色。
猫的肾脏表达 L-FABP。在 5 只 uL-FABP 排泄量高的猫的近端肾小管腔中观察到强烈的 L-FABP 信号，但在 5 只 uL-FABP 排泄量低的猫中未观察到。在 9 只正常猫中，uL-FABP 指数<1.2μg/g 尿肌酐（uCre）。在 100 只 sCre 较低（<1.6mg/dL）的猫中检测到 7 只 uL-FABP 指数较高（>10.0μg/g uCre），在 44 只 sCre 较高（>1.6mg/dL）的猫中检测到 18 只 uL-FABP 指数较高。L-FABP 指数与 sCre、血清对称二甲基精氨酸（SDMA）或血尿素氮（BUN）之间呈弱相关，通过仅分析 sCre>1.6mg/dL 的猫的数据，这些相关系数增加。在所有测试的猫中，uL-FABP 指数与 sL-FABP 之间存在弱相关性，但在 sCre 较高的猫中没有相关性。
本研究表明，L-FABP 与猫慢性肾脏病的当前肾脏生物标志物（如 sCre 和 SDMA）之间存在相关性。L-FABP 可能是预测猫肾脏早期病理生理事件的潜在生物标志物。
