Individual variability in human urinary metabolites identifies age-related, body mass index-related, and sex-related biomarkers.

BACKGROUND: Metabolites present in human urine can be influenced by individual physiological parameters (e.g., body mass index [BMI], age, and sex). Observation of altered metabolites concentrations could provide insight into underlying disease pathology, disease prognosis and diagnosis, and facilitate discovery of novel biomarkers. METHODS: Quantitative metabolomics analysis in the urine of 183 healthy individuals was performed based on high-resolution liquid chromatography-mass spectrometry (LC-MS). Coefficients of variation were obtained for 109 urine metabolites of all the 183 human healthy subjects. RESULTS: Three urine metabolites (such as dehydroepiandrosterone sulfate, acetaminophen glucuronide, and p-anisic acid) with CV183  > 0.3, for which metabolomics studies have been scarce, are considered highly variable here. We identified 30 age-related metabolites, 18 BMI-related metabolites, and 42 sex-related metabolites. Among the identified metabolites, three metabolites were found to be associated with all three physiological parameters (age, BMI, and sex), which included dehydroepiandrosterone sulfate, 3-methylcrotonylglycine and N-acetyl-aspartic acid. Pearson's coefficients demonstrated that some age-, BMI-, and sex-related compounds are strongly correlated, suggesting that age, BMI, and sex could affect them concomitantly. CONCLUSION: Metabolic differences between distinct physiological statuses were found to be related to several metabolic pathways (such as the caffeine metabolism, the amino acid metabolism, and the carbohydrate metabolism), and these findings may be key for the discovery of new diagnostics and treatments as well as new understandings on the mechanisms of some related diseases.

Synthesis and Biological Evaluation of HDAC Inhibitors With a Novel Zinc Binding Group.

Vorinostat (SAHA) with great therapeutic potential has been approved by the FDA for the treatment of cutaneous T-cell lymphoma as the first HDACs inhibitor, but the drawbacks associated with hydroxamic acid group (poor stability, easy metabolism, weak binding ability to class IIa isozymes, and poor selectivity) have been exposed during the continuous clinical application. Based on the pharmacophore of HDAC inhibitors, two series of compounds with novel zinc binding group (ZBG) were designed and synthesized, and the antitumor bioactivities were evaluated in four human cancer cell lines (A549, Hela, HepG2, and MCF-7). Among the synthesized compounds, compounds a6, a9, a10, b8, and b9 exhibited promising inhibitory activities against the selected tumor cell lines, especially compounds a9 and b8 on Hela's cytostatic activity (a9: IC50 = 11.15 ± 3.24 µM; b8: IC50 = 13.68 ± 1.31 µM). The enzyme inhibition assay against Hela extracts and HDAC1&6 subtypes showed that compound a9 had a certain broad-spectrum inhibitory activity, while compound b8 had selective inhibitory activity against HDAC6, which was consistent with Western blot results. In addition, the inhibitory mechanism of compounds a9 and b8 in HDAC1&6 were both compared through computational approaches, and the binding interactions between the compounds and the enzymes target were analyzed from the perspective of energy profile and conformation. In summary, the compounds with novel ZBG exhibited certain antitumor activities, providing valuable hints for the discovery of novel HDAC inhibitors.

Exploring the binding mechanism of HDAC8 selective inhibitors: Lessons from the modification of Cap group.

The abnormal expression of histone deacetylase 8 (HDAC8) has been reported to associate with various cancer entities (colon, breast cancer, pancreas, etc.) as well as parasitic diseases, making HDAC8 gradually develop into an attractive and potential therapeutic target. Among the various design strategies of selective HDAC8 inhibitors (modification of Cap, Linker, or zinc binding group regions), the optimization of Cap region has aroused great interest among the researchers. However, the detailed information underlying how the modification of Cap region influences the inhibitory activities is still unclear, and in this study, compounds 2c, 3g, and 3n were selected to explore the differences in binding mechanisms brought by Cap modifications via various computational approaches at the atomic level. Five residues (Y293, H167, D254, D165, and M261) have a large difference in energy contributions to the constructed systems, and the subpocket formed by Y293 and M261 could interact with Cap groups, triggering the differences in the energy contributions of the residues (H167, D254, and D165) located in metal-catalytic center. In summary, the compounds 2c, 3g, and 3n were selected as molecular probes to explore the binding mechanism, and the residues (Y293 and M261) forming the subpocket should be paid special attention in the design and synthesis of novel selective HDAC8 inhibitors.

Anti-acute myeloid leukemia activity of 2-chloro-3-alkyl-1,4-naphthoquinone derivatives through inducing mtDNA damage and GSH depletion.

2-Chloro-3-alkyl-1,4-naphthoquinone derivatives were synthesized and tested as the anti-acute myeloid leukaemia agents. The compound 9b (2-chloro-3-ethyl-5,6,7-trimethoxy-1,4-naphthoquinone) was the most potent toward HL-60 leukaemia cells. In mechanistic study for 9b, the protein levels of mtDNA-specific DNA polymerase γ (poly-γ) and mtDNA transcription factor A (mt-TFA) were decreased after the 24 h treatment, showing the occurrence of mtDNA damage. And 9b triggered cell cycle arrest at S phase accompanied by a secondary block in G2/M phase which had a direct link to the process of mtDNA damage. The dissipations of mitochondrial membrane potential and ATP also proceeded. On the other hand, 9b promoted the generation of ROS and resulted in the oxidation of intracellular GSH to GSSG. This process was coupled to the formation of adduct between 9b and GSH, detected by the UV-Vis spectrum and HRMS analysis. Depletion of GSH by buthionine sulfoximine enhanced ROS level and produced higher cytotoxicity, suggesting GSH was involved in the anti-leukemic mechanism of 9b. Together, our results provide new insights on the molecular mechanism of the derivatives of 2-chloro-1,4-naphthoquinone and 9b might be useful for the further development into an anti-leukemia agent.