Multiorgan Systems Study Reveals Igfbp7 as a Suppressor of Gluconeogenesis after Gastric Bypass Surgery.

Roux-en-Y gastric bypass (RYGB) surgery reduces weight in obese patients. A marked decrease in blood glucose levels occurs before weight loss; however, key molecules that improve the glycemic profile remain largely unknown. Using a murine RYGB surgery model, we performed multiorgan proteomics and bioinformatics to monitor the proteins and molecular pathways that change in this early glycemic response. Multiplexed proteomic kinetics data analysis revealed that the Roux limb, biliopancreatic limb, liver, and pancreas each exhibited unique temporal and molecular responses to the RYGB surgery. In addition, protein-protein network analysis indicated that the changes to the microbial environment in the intestine may play a crucial role in the beneficial effects of RYGB surgery. Furthermore, insulin-like growth factor binding protein 7 (Igfbp7) was identified as an early induced protein in the Roux limb. Known secretory properties of Igfbp7 prompted us to further investigate its role as a remote organ regulator of glucose metabolism. Igfbp7 overexpression decreased blood glucose levels in diet-induced obese mice and attenuated gluconeogenic gene expression in the liver. Secreted Igfbp7 appeared to mediate these beneficial effects. These results demonstrate that organs responded differentially to RYGB surgery and indicate that Igfbp7 may play an important role in improving blood glucose levels.

A Study into the ADP-Ribosylome of IFN-γ-Stimulated THP-1 Human Macrophage-like Cells Identifies ARTD8/PARP14 and ARTD9/PARP9 ADP-Ribosylation.

ADP-ribosylation is a post-translational modification that, until recently, has remained elusive to study at the cellular level. Previously dependent on radioactive tracers to identify ADP-ribosylation targets, several advances in mass spectrometric workflows now permit global identification of ADP-ribosylated substrates. In this study, we capitalized on two ADP-ribosylation enrichment strategies, and multiple activation methods performed on the Orbitrap Fusion Lumos, to identify IFN-γ-induced ADP-ribosylation substrates in macrophages. The ADP-ribosyl binding protein, Af1521, was used to enrich ADP-ribosylated peptides, and the antipoly-ADP-ribosyl antibody, 10H, was used to enrich ADP-ribosylated proteins. ADP-ribosyl-specific mass spectra were further enriched by an ADP-ribose product ion triggered EThcD and HCD activation strategy, in combination with multiple acquisitions that segmented the survey scan into smaller ranges. HCD and EThcD resulted in overlapping and unique ADP-ribosyl peptide identifications, with HCD providing more peptide identifications but EThcD providing more reliable ADP-ribosyl acceptor sites. Our acquisition strategies also resulted in the first ever characterization of ADP-ribosyl on three poly-ADP-ribose polymerases, ARTD9/PARP9, ARTD10/PARP10, and ARTD8/PARP14. IFN-γ increased the ADP-ribosylation status of ARTD9/PARP9, ARTD8/PARP14, and proteins involved in RNA processes. This study therefore summarizes specific molecular pathways at the intersection of IFN-γ and ADP-ribosylation signaling pathways.

Synthesis of highly deuterium-labeled (R)-K-13675, PPAR alpha agonist, for use as an internal standard for low-level quantification of drugs in plasma.

Two highly deuterium-labeled compounds, (R)-K-13675-d(11) and (R)-K-13675-d(7), were prepared for use as internal standards for low-level quantification of plasma drugs by LC/MS/MS. We successfully demonstrated their utility in pharmacokinetic studies for sensitive and precise drug quantification.

Design and synthesis of highly potent and selective human peroxisome proliferator-activated receptor alpha agonists.

A combination of benzoxazole, phenoxyalkyl side chain, and phenoxybutyric acids was identified as a highly potent and selective human peroxisome proliferator-activated receptor alpha (PPARalpha) agonist. The synthesis, structure-activity relationship (SAR) studies, and in vivo activities of the representative compounds are described.