Methionine aminopeptidase (MetAP) carries out an essential function of protein N-terminal processing in many bacteria and is a promising target to develop novel antitubercular agents. Natural bengamides potently inhibit proliferation of mammalian cells by targeting MetAP enzymes, and the X-ray structure of human type 2 MetAP in complex with a bengamide derivative revealed the key interactions at the active site. By preserving the interactions with the conserved residues inside the binding pocket while exploring the differences between bacterial and human MetAPs around the binding pocket, seven bengamide derivatives were synthesized and evaluated for inhibition of MtMetAP1a and MtMetAP1c in different metalloforms, inhibition of growth of M. tuberculosis in replicating and non-replicating states, and inhibition of growth of human K562 cells. Potent inhibition of MtMetAP1a and MtMetAP1c and modest growth inhibition of M. tuberculosis were observed for some of these derivatives. X-ray structures of MtMetAP1c in complex with two of the derivatives provided the valuable structural information for improvement of these inhibitors for potency and selectivity.

Both in vitro and in vivo metabolism studies suggested that 5-(2,8-bis(trifluoromethyl)quinolin-4-yloxymethyl)isoxazole-3-carboxylic acid ethyl ester (compound 3) with previously reported antituberculosis activity is rapidly converted to two metabolites 3a and 3b. In order to improve the metabolic stability of this series, chemistry efforts were focused on the modification of the oxymethylene linker of compound 3 in the present study. Compound 9d with an alkene linker was found to be both more metabolically stable and more potent than compound 3, with a minimum inhibitory concentration (MIC) of 0.2 microM and 2.6 microM against replicating and nonreplicating Mycobaterium tuberculosis, respectively. These attributes make 9d an interesting lead compound. A number of modifications were made to the structure of 9d, and a series of active compounds were discovered. Although some neurotoxicity was observed at a high dosage, this new series was endowed with both improved in vitro anti-TB activity and metabolic stability in comparison to compound 3.

We assembled an ancestrally diverse collection of genome-wide association studies of type 2 diabetes (T2D) in 180,834 cases and 1,159,055 controls (48.9% non-European descent). We identified 277 loci at genome-wide significance (p<5x10-8), including 237 attaining a more stringent trans-ancestry threshold (p<5x10-9), which were delineated to 338 distinct association signals. Trans-ancestry meta-regression offered substantial enhancements to fine-mapping, with 58.6% of associations more precisely localised due to population diversity, and 54.4% of signals resolved to a single variant with >50% posterior probability. This improved fine-mapping enabled systematic assessment of candidate causal genes and molecular mechanisms through which T2D associations are mediated, laying foundations for functional investigations. Trans-ancestry genetic risk scores enhanced transferability across diverse populations, providing a step towards more effective clinical translation to improve global health.

A box has remarkable protective effect against pancreatitis and associated organ injury; HMGB1 probably participates in the inflammatory reaction and organ injury of SAP as a late-acting mediator of inflammation.

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Severe acute pancreatitis (SAP) is an extremely dangerous acute abdominal disorder which causes multiple complications and has a high mortality rate. Previous research has suggested that high-mobility group box 1 (HMGB1) plays an important role in the pathogenesis of SAP; however, the mechanisms underlying this strong correlation remain unclear. In this study, to further investigate whether HMGB1 acts as a stimulating factor, and whether Toll-like receptor 4 (TLR4) acts as its major mediator in the development of pancreatic injury during SAP, recombinant human HMGB1 (rhHMGB1) and TLR4-deficient mice were used. We found that HMGB1 and TLR4 were highly expressed, and nuclear factor-κB (NF-κB) was activated in our mouse model of SAP. We noted that the rhHMGB1 pancreas-targeted injection activated the TLR4-mediated NF-κB signaling pathway and induced pancreatic injury in wild-type mice. In TLR4-deficient mice, the rhHMGB1-induced activation of NF-κB and pathological changes in the pancreas were less evident than in wild-type mice. Therefore, this study provides evidence that HMGB1 promotes the pathogenesis of pancreatitis, and its downstream TLR4-mediated NF-κB signaling pathway is a potential important mediator in the development of this form of pancreatic injury.

Background and aimsDetermine the effect of AMPK activation and inhibition on the development of AAA (abdominal aortic aneurysm).MethodsAAA was induced in ApoE−/− mice by Ang II (Angiotensin II)-infusion. AICAR (5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside) was used as AMPK activator and Compound C was used as AMPK inhibitor. We further investigate the effect of metformin, a widely used anti-diabetic drug which could activate AMPK signal pathway, on the pathogenesis of aneurysm.ResultsPhospho-AMPK level was significantly decreased in AAA tissue compared with control aortas. AICAR significantly reduced the incidence, severity and mortality of aneurysm in the Ang II-infusion model. AICAR also alleviated macrophage infiltration and neovascularity in Ang II infusion model at day 28. The expression of pro-inflammatory factors, angiogenic factors and the activity of MMPs were also alleviated by AICAR during AAA induction. On the other hand, Compound C treatment did not exert obvious protective effect. AMPK activation may inhibit the activation of nuclear factor-κB (NF-κB) and signal transducer and activator of transcription-3 (STAT-3) during AAA induction. Administration of metformin also activated AMPK signal pathway and retarded AAA progression in Ang II infusion model.ConclusionsActivation of AMPK signaling pathway may inhibit the Ang II-induced AAA in mice. Metformin may be a promising approach to the treatment of AAA.

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