Metabonomic analysis of liver tissue from BALB/c mice with D-galactosamine/lipopolysaccharide-induced acute hepatic failure

The hypotaurine-taurine pathway as an antioxidative mechanism in patients with acute liver failure

The liver has been thought to protect against oxidative stress through mechanisms involving reduced glutathione (GSH) that consumes high-energy phosphor-nucleotides on its synthesis. However, hepatoprotective mechanisms in acute liver failure (ALF) where the phosphor-nucleotides are decreased in remain to be solved. Liver tissues were collected from patients with ALF and liver cirrhosis (LC) and living donors (HD) who had undergone liver transplantation. Tissues were used for metabolomic analyses to determine metabolites belonging to the central carbon metabolism, and to determine sulfur-containing metabolites. ALF and LC exhibited a significant decline in metabolites of glycolysis and pentose phosphate pathways and high-energy phosphor-nucleotides such as adenosine triphosphate as compared with HD. Conversely, methionine, S-adenosyl-l-methionine, and the ratio of serine to 3-phosphoglycerate were elevated significantly in ALF as compared with LC and HD, suggesting a metabolic boost from glycolysis towards trans-sulfuration. Notably in ALF, the increases in hypotaurine (HTU) + taurine (TU) coincided with decreases in the total amounts of reduced and oxidized glutathione (GSH + 2GSSG). Plasma NH₃ levels correlated with the ratio of HTU + TU to GSH + 2GSSG. Increased tissue levels of HTU + TU vs total glutathione appear to serve as a biomarker correlating with hyperammonemia, suggesting putative roles of the HTU-TU pathway in anti-oxidative protective mechanisms.

Estrogen-Related Receptor γ Agonist DY131 Ameliorates Lipopolysaccharide-Induced Acute Liver Injury

Sepsis-associated liver dysfunction remains a challenge in clinical practice with high mortality and limited specific therapies. DY131 is a pharmacological agonist of the orphan receptor estrogen-related receptor (ERR) γ which plays a crucial role in regulating energy generation, oxidative metabolism, cell apoptosis, inflammatory responses, etc. However, its role in acute liver injury is unknown. In this study, we evaluated the effect of DY131 on lipopolysaccharide (LPS)-induced liver injury. Mice were pretreated with DY131 through intraperitoneal injection at a dose of 5 mg/kg/day for 3 days prior to LPS challenge (10 mg/kg). 24 h later, they were anesthetized and sacrificed. Blood and liver tissues were collected for further studies. In a separate experiment, mice were treated with saline (vehicle) or DY131 for 3 days to evaluate the toxicity of DY131. We found that ERRγ was downregulated in the liver tissues from LPS-treated mice. Pretreatment with DY131 ameliorated LPS-induced liver injury as demonstrated by reduced liver enzyme release (ALT, AST, and LDH), improved liver morphological damage, and attenuated oxidative stress, inflammation and apoptosis. Meanwhile, DY131 had no significant side effects on hepatic and renal functions in mice. Finally, transcriptomics analysis revealed that the dysregulated pathways associated with inflammation and metabolism were significantly reversed by DY131 in LPS-treated mice, providing more evidence in favor of the protective effect of DY131 against LPS-induced liver injury. Altogether, these findings highlighted the protective effect of DY131 on LPS-induced hepatotoxicity possibly via suppressing oxidative stress, inflammation, and apoptosis.

Serum Metabolomic Profiling to Reveal Potential Biomarkers for the Diagnosis of Fatty Liver Hemorrhagic Syndrome in Laying Hens

Fatty liver hemorrhage syndrome (FLHS), a nutritional and metabolic disease that frequently occurs in laying hens, causes serious losses to the poultry industry. Nowadays, the traditional clinical diagnosis of FLHS still has its limitations. Therefore, searching for some metabolic biomarkers and elucidating the metabolic pathway in vivo are useful for the diagnosis and prevention of FLHS. In the present study, a model of FLHS in laying hens induced by feeding a high-energy, low-protein diet was established. Gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) was used to analyze the metabolites in serum at days 40 and 80. The result showed that, in total, 40 differential metabolites closely related to the occurrence and development of FLHS were screened and identified, which were mainly associated with lipid metabolism, amino acid metabolism, and energy metabolism pathway disorders. Further investigation of differential metabolites showed 10 potential biomarkers such as 3-hydroxybutyric acid, oleic acid, palmitoleic acid, and glutamate were possessed of high diagnostic values by analyzing receiver operating characteristic (ROC) curves. In conclusion, this study showed that the metabolomic method based on GC-TOF-MS can be used in the clinical diagnosis of FLHS in laying hens and provide potential biomarkers for early risk evaluation of FLHS and further insights into FLHS development.

A systems pharmacology-oriented discovery of a new therapeutic use of the TCM formula Liuweiwuling for liver failure

Multiple components of traditional Chinese medicine (TCM) formulae determine their treatment targets for multiple diseases as opposed to a particular disease. However, discovering the unexplored therapeutic potential of a TCM formula remains challenging and costly. Inspired by the drug repositioning methodology, we propose an integrated strategy to feasibly identify new therapeutic uses for a formula composed of six herbs, Liuweiwuling. First, we developed a comprehensive systems approach to enrich drug compound-liver disease networks to analyse the major predicted diseases of Liuweiwuling and discover its potential effect on liver failure. The underlying mechanisms were subsequently predicted to mainly attribute to a blockade of hepatocyte apoptosis via a synergistic combination of multiple effects. Next, a classical pharmacology experiment was designed to validate the effects of Liuweiwuling on different models of fulminant liver failure induced by D-galactosamine/lipopolysaccharide (GalN/LPS) or thioacetamide (TAA). The results indicated that pretreatment with Liuweiwuling restored liver function and reduced lethality induced by GalN/LPS or TAA in a dose-dependent manner, which was partially attributable to the abrogation of hepatocyte apoptosis by multiple synergistic effects. In summary, the integrated strategy discussed in this paper may provide a new approach for the more efficient discovery of new therapeutic uses for TCM formulae.

Detecting serum and urine metabolic profile changes of CCl4-liver fibrosis in rats at 12 weeks based on gas chromatography-mass spectrometry

Liver fibrosis is caused by liver injury induced by a number of chronic liver diseases, including schistosome infection, hepatitis infection, metabolic disease, alcoholism and cholestasis. The tissue damage occurring after injury or inflammation of the liver is a reversible lesion; however, liver fibrosis has become a worldwide problem and poses a threat to human health. The development of an effective drug for the prevention and treatment of liver fibrosis is ongoing and uses information from different occurrences of liver fibrosis. In the present study, carbon tetrachloride (CCl₄)-induced metabonomic changes in serum and urine at 12 weeks were analyzed using gas chromatography-mass spectrometry (GC/MS) to investigate potential biomarkers. Liver fibrosis was induced in rats by subcutaneous injections of CCl₄ twice a week for 12 consecutive weeks. Histopathological changes were used to assess the successful production of a CCl₄-induced liver fibrosis model. Serum and urine samples from the two groups were collected at 12 weeks. The metabolic profile changes were analyzed by GC/MS alongside principal component analysis and orthogonal projections to latent structures. Metabolic profile studies indicated that the clustering of the two groups could be separated and seven metabolites in serum and five metabolites in urine were identified. In serum, the metabolites identified included isoleucine, L-malic acid, α-copper, carnitine, hippuric acid, glutaric acid and glucose. In urine 2-hydroxy butyric acid, isoleucine, N-acetyl-β-alanine, cytidine and corticoid were identified. The present study demonstrated that the pathogenesis of liver fibrosis may be associated with the dysfunction of a number of metabolic pathways, including glucose, amino acid, P450, fatty acid, nucleic acid, water-electrolyte and glutathione biosynthesis. Assessing potential biomarkers may therefore provide novel targets and theories for the innovation of novel drugs to prevent and cure liver fibrosis.

Multi-dimensional, comprehensive sample extraction combined with LC-GC/MS analysis for complex biological samples: application in the metabolomics study of acute pancreatitis

Multi-dimensional sample extraction and optimal LC-GC/MS were combined to obtain as much sample information as possible for metabolomics applications.