Identification of liver disease-specific peptide by sugar chain profiling

我们使用2D-μHPLC-MALDI-TOF-MS鉴定了α-胰蛋白酶抑制剂重链4（ITIH4）肽作为一种新的肝脏疾病血清生物标志物。我们还开发了免疫质谱系统来处理大量的样品。利用该系统，我们确定了这种生物标志物肽在检测肝硬化和肝细胞癌（HCC）中的效用。此外，该肽可用于检测非酒精性脂肪肝疾病。含该肽的35kD蛋白片段经糖链修饰分为10个同工异构体，早期HCC患者血清中9和10同工异构体水平升高。这些异构体是HCC的有用生物标志物，可能与肝癌发生有关。

We identified inter-α-trypsin inhibitor heavy chain 4(ITIH4) peptide as a novel serum biomarker for liver disease using 2D-μHPLC-MALDI-TOF-MS. Also we developed immuno-MS system to deal with many samples. Using this system, we determined the utility of this biomarker peptide for detecting liver cirrhosis and hepatocellular carcinoma(HCC). Moreover, this peptide was useful for detecting non-alcoholic fatty liver diseases. And 35kD protein fragment including this peptide was divided into ten isoforms by the sugar chain modification, and serum isofrom 9 and 10 levels were elevated in early HCC patients. These isoforms are useful biomarker for HCC and may be related to hepatic carcinogenesis.