Functional metabolomics revealed functional metabolic-characteristics of chronic hepatitis that is significantly differentiated from acute hepatitis in mice.

Diagnosis and therapeutics of acute- and chronic- hepatitis (A-H and C-H) cannot be distinguished during clinical practice because functional molecular-characteristics of two conditions remains elusive. Here, we employed a functional metabolomics strategy to discover functional metabolites that can readily distinguish C-H from A-H in CCl4 treated mice. Metabolic-differentiation between A-H and C-H was identified as A-H was largely characterized by the dysregulated purine cycle and amino acid metabolism, while the disorders of hepatic taurine-conjugated bile acids and glycerolipid biosynthesis were observed with C-H. Excitingly, we found that the enhanced conversation of C18-22 PUFA-containing TAGs to MUFA-containing TAGs promoted the development of C-H, which was also closely associated with the changes of TCA intermediates regulated by gut microbiota (Muribaculaceae and Prevotellaceae). Such metabolic discovery on hepatitis was validated by the functional annotation of metabolic genes, as the decreased expressions of Slc27a2, Acaa1a and Acaa1b mostly account for the dysregulation of purine degradation with AH, then the lowered expressions of Cyp2e1, Cat, Slc27a5 and Klb are significantly related to the dysregulated bile acids with C-H. Collecting clinical samples from the patients with hepatitis to compare serum metabolomes with A-H and C-H mice, the determinant functional metabolites were identified to significantly distinguish C-H from A-H in both experimental and clinical settings, suggesting metabolic discovery with CCl4 treated mice could be further efficiently explored to guide clinical research of A-H and C-H. Collectively, our study is providing novel insight into distinctive metabolic-characteristics of A-H and C-H underlying the innovative diagnosis and therapeutics of hepatitis.

Constitutively-active human LH receptors are self-associated and located in rafts.

Several naturally occurring mutations in human luteinizing hormone receptors (LHR) at position 578 are associated with constitutive activation of the receptor. To determine whether human LHRs that signal in the absence of ligand are self-associated, fluorescence resonance energy transfer (FRET) between receptors was evaluated. Values for FRET between wild type LHR in the absence of ligand were less than 1% and increased significantly to over 11% after exposure to hCG. Constitutively active receptors exhibited 11-15% FRET efficiency in the absence of hormone and these values did not change with hCG treatment. A large fraction of constitutively active LHR-D578H receptors were also associated with so-called plasma membrane rafts. Disruption of these membrane microdomains reduced FRET efficiency but did not affect signalling through cAMP. Thus, in the absence of ligand, constitutively active receptors are self-associated and located in high buoyancy membrane fractions, both characteristics of the hormone-treated wild type receptor.