BACKGROUND/AIMS: Metabolomics is a powerful tool for measuring low-molecular-weight metabolites in an organism at a specified time under specific environmental conditions. The aim of this study was to determine the usefulness of metabolomics in identifying the metabolites in stool-fat-positive specimens, and to establish whether the results could be used to predict the long-term prognosis. METHODS: Fecal specimens were collected from 52 subjects with bowel habit change. The subjects were accessed using Rome III questionnaires and Bristol stool scale form, and followed after three years. The feces samples were centrifuged and the resulting extracts reconstituted for liquid chromatography/mass spectrometry analysis. The datasets were autoscaled, log-transformed, and mean-centered in a column-wise fashion prior to principal-components analysis and partial least-squares-discrimination analysis modeling. RESULTS: Fecal samples from 10 of the 52 patients gave a positive stool-fat result of 30-100 microm; those of the remaining 42 contained neither fatty acids nor neutral fats. The peak intensities of lithocholic acid (p=0.001), lysophosphatidyl ethanolamine (lysoPE) 16:0 (p=0.015), and lysoPE 18:1/0:0 (p=0.014) were correlated with the size of the fatty acid. Subjects with positive stool-fat result showed higher score in Bristol stool scale form than those with negative stool-fat result at initial (p=0.040) and after three years (p=0.012). CONCLUSIONS: The metabolomic assay of stool fatty acid revealed mainly lysoPEs and lithocholic acid. The size of the fatty acid was correlated with higher concentrations of lysoPEs and lithocholic acid in stool-fat-test-positive specimens and related to loose stool even after three years of follow-up period.
Adult ; Aged ; Chromatography, High Pressure Liquid ; Fatty Acids/*analysis ; Feces/*chemistry ; Female ; Follow-Up Studies ; Humans ; Least-Squares Analysis ; Lithocholic Acid/analysis ; Lysophospholipids/analysis ; Male ; *Metabolomics ; Middle Aged ; Principal Component Analysis ; Questionnaires ; Spectrometry, Mass, Electrospray Ionization

BACKGROUND/AIMS: Chronic liver disease leads to liver fibrosis, and although the liver does have a certain regenerative capacity, this disease is associated with dysfunction of the liver vessels. C-reactive protein (CRP) is produced in the liver and circulated from there for metabolism. CRP was recently shown to inhibit angiogenesis by inducing endothelial cell dysfunction. The objective of this study was to determine the effect of CRP levels on angiogenesis in a rat model of liver dysfunction induced by bile duct ligation (BDL). METHODS: The diameter of the hepatic vein was analyzed in rat liver tissues using hematoxylin and eosin (H&E) staining. The expression levels of angiogenic factors, albumin, and CRP were analyzed by real-time PCR and Western blotting. A tube formation assay was performed to confirm the effect of CRP on angiogenesis in human umbilical vein endothelial cells (HUVECs) treated with lithocholic acid (LCA) and siRNA-CRP. RESULTS: The diameter of the hepatic portal vein increased significantly with the progression of cirrhosis. The expression levels of angiogenic factors were increased in the cirrhotic liver. In contrast, the expression levels of albumin and CRP were significantly lower in the liver tissue obtained from the BDL rat model than in the normal liver. The CRP level was correlated with the expression of albumin in hepatocytes treated with LCA and siRNA-CRP. Tube formation was significantly decreased in HUVECs when they were treated with LCA or a combination of LCA and siRNA-CRP. CONCLUSION: CRP seems to be involved in the abnormal formation of vessels in hepatic disease, and so it could be a useful diagnostic marker for hepatic disease.
Angiogenic Proteins/genetics/metabolism ; Animals ; Bile Ducts/surgery ; C-Reactive Protein/*analysis/genetics/metabolism ; Cells, Cultured ; Disease Models, Animal ; Hepatic Veins/abnormalities ; Hepatocytes/cytology/metabolism ; Human Umbilical Vein Endothelial Cells ; Humans ; Lithocholic Acid/pharmacology ; Liver/metabolism/pathology ; Liver Cirrhosis/etiology ; Liver Diseases/metabolism/*pathology ; Male ; Microscopy, Fluorescence ; Mitochondria/drug effects/metabolism ; RNA Interference ; RNA, Small Interfering/metabolism ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Serum Albumin/genetics/metabolism