A Metabonomic Investigation on the Biochemical Perturbation in Liver Failure Patients Caused by Hepatitis B Virus Ke Yu,†,# Guoping Sheng,‡,# Jifang Sheng,‡ Yuemei Chen,‡ Wei Xu,‡ Xiaoli Liu,‡ Hongcui Cao,‡ Haibin Qu,† Yiyu Cheng,*,†,‡ and Lanjuan Li*,‡ Pharmaceutical Informatics Institute, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China, and Key Laboratory of Infectious Diseases, Ministry of Health, Department of Infectious Diseases, 1st Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China Received November 9, 2006
A metabonomic study was performed to investigate the biochemical perturbation of the serum samples from liver failure patients induced by hepatitis B virus (HBV; n ) 24) and control normal subjects (n ) 23). The serum metabonome was detected using gas chromatography-mass spectrometry (GC-MS) technique integrated with a commercial mass spectral library for the peak identification. After peak deconvolution, identification, and matching, the acquired GC-MS data were normalized and processed by principal component analysis (PCA) and canonical discriminant analysis (CDA). Specific changes in the metabolic composition of serum samples from patients including amino acids (AAs) and glucose were shown in GC-MS total ion current (TIC) chromatograms. The distinctive biochemical difference between the healthy subjects and liver failure patients was displayed by the pattern recognition methods. We also found that the liver failure patients with different degree of severity categorized as MELD (model for end-stage of liver diseases) could be clearly classified by the corresponding metabonomic data. In comparison, the current routine clinical indices cannot characterize the global phenotyping of liver failure. The result demonstrated that the GC-MS technique is an alternative tool for the characterization of the metabolic perturbation and the metabonomic study promises to provide an integrative criterion to evaluate the severity and the prognosis of liver diseases. Keywords: Metabonomics • hepatitis B • GC-MS • PCA • liver failure
1. Introduction It is estimated that approximately 350 million people worldwide and 120 million in China alone are infected with hepatitis B virus (HBV).1-4 The HBV-infected persons are at risk of chronic hepatitis, liver failure, cirrhosis, and hepatocellular carcinoma. Among these liver diseases, liver failure is the most emergent clinic complication which leads to the highest mortality, though some new therapy methods have appeared.5-7 It has been observed that changes of low and middle molecular weight compounds in human serum are detectable when patients are suffering with the liver diseases.8,9 For example, the concentration of putative toxins (ammonia, γ-aminobutyric acid, endogenous benzodiazepines, and tryptophan, etc.) in human serum will increase when mass liver tissue is damaged.10 Since the metabolism is mainly carried out in the liver, the levels of many endogenous metabolites might be sensitive to liver injury.11 * To whom correspondence should be addressed. (For L. Li): e-mail,
[email protected]; phone, +86-571-87236759; fax, +86-571-87236755. (For Y. Cheng): e-mail,
[email protected]; phone, +86-571-87951138; fax, +86-571-87951138. † Zhejiang University. # These two authors provided the same contribution to this paper. ‡ Zhejiang University School of Medicine. 10.1021/pr060591d CCC: $37.00
2007 American Chemical Society
Molecular systems biology has been proposed as an alternative and promising resolution for understanding and elucidating the etiology and mechanisms of human diseases.12 The developments of analytical techniques have enhanced the capability for the global assessment of entire classes of biomolecules such as genome, proteome, and metabonome. Metabonomics, defined as “the quantitative measurement of the multiparametric metabolic response of living systems to pathophysicological stimuli or genetic modification”,13,14 is a novel methodology arising from the post-genomics era for the study of molecular systems biology. The information obtained from metabonomic study is also complementary to that from proteomics and genomics. Nowadays, metabonomics has been applied to various biomedical and toxicological studies. Because the alteration of the physiological status can disrupt homeostasis, resulting in perturbations of the levels of endogenous biochemicals involved in different kinds of key metabolic processes, the metabonomic study may provide both invaluable information to understand the molecular mechanisms and provide novel insights into the status of dysfunction in biological system. The “-omics” approaches, especially the proteomics with the global analysis of protein expression, have been employed to screen the molecular markers which can be used as serological Journal of Proteome Research 2007, 6, 2413-2419
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Published on Web 06/01/2007
research articles
Yu et al.
Table 1. Demographic Information of the Healthy Group and Liver Failure Patient Group Investigateda
Gender (male/female) HBsAg Age (year) ALT (U/L) TB (µmol/L) PT (s) MELD score
healthy group (n ) 23)
patient group (n ) 24)
15/8 Negative 27.39 ( 9.24
