High-Throughput Acoustic Ejection Mass Spectrometry with Adjustable Signal Durations

High-throughput mass spectrometry (MS) has witnessed rapid advancements and has found extensive applications across various disciplines. It enables the fast and accurate analysis of large sample sets, delivering a 10-fold or greater enhancement in analytical throughput when compared to conventional LC-MS methods. However, the signal duration in these high-throughput MS technologies is typically confined to a narrow range, presenting challenges for workflows demanding prolonged signal durations. In this study, we introduce a method that enables precise modulation of the signal duration on an acoustic ejection mass spectrometry (AEMS) system while ensuring high signal reproducibility. This flexibility allows for simultaneous and precise analysis of a significantly greater number of MS/MS transitions in high-throughput MS environments. Additionally, it offers a unique approach for parameter optimization and method development with minimal sample volume requirements. This advancement enhances the efficiency of MS-based analyses across diverse applications and facilitates broader utilization of MS technologies in high-throughput settings, including data-dependent acquisition (DDA) and data-independent acquisition (DIA).

The liver-gut microbiota axis modulates hepatotoxicity of tacrine in the rat

The gut microbiota possesses diverse metabolic activities, but its contribution toward heterogeneous toxicological responses is poorly understood. In this study, we investigated the role of the liver-gut microbiota axis in underpinning the hepatotoxicity of tacrine. We employed an integrated strategy combining pharmacokinetics, toxicology, metabonomics, genomics, and metagenomics to elucidate and validate the mechanism of tacrine-induced hepatotoxicity in Lister hooded rats. Pharmacokinetic studies in rats demonstrated 3.3-fold higher systemic exposure to tacrine in strong responders that experienced transaminitis, revealing enhanced enterohepatic recycling of deglucuronidated tacrine in this subgroup, not attributable to variation in hepatic disposition gene expression. Metabonomic studies implicated variations in gut microbial activities that mapped onto tacrine-induced transaminitis. Metagenomics delineated greater deglucuronidation capabilities in strong responders, based on differential gut microbial composition (e.g., Lactobacillus, Bacteroides, and Enterobacteriaceae) and approximately 9% higher β-glucuronidase gene abundance compared with nonresponders. In the validation study, coadministration with oral β-glucuronidase derived from Escherichia coli and pretreatment with vancomycin and imipenem significantly modulated the susceptibility to tacrine-induced transaminitis in vivo.

CONCLUSION

This study establishes pertinent gut microbial influences in modifying the hepatotoxicity of tacrine, providing insights for personalized medicine initiatives. (Hepatology 2018;67:282-295).

Discovery of GSK2795039, a Novel Small Molecule NADPH Oxidase 2 Inhibitor

AIMS

The NADPH oxidase (NOX) family of enzymes catalyzes the formation of reactive oxygen species (ROS). NOX enzymes not only have a key role in a variety of physiological processes but also contribute to oxidative stress in certain disease states. To date, while numerous small molecule inhibitors have been reported (in particular for NOX2), none have demonstrated inhibitory activity in vivo. As such, there is a need for the identification of improved NOX inhibitors to enable further evaluation of the biological functions of NOX enzymes in vivo as well as the therapeutic potential of NOX inhibition. In this study, both the in vitro and in vivo pharmacological profiles of GSK2795039, a novel NOX2 inhibitor, were characterized in comparison with other published NOX inhibitors.

RESULTS

GSK2795039 inhibited both the formation of ROS and the utilization of the enzyme substrates, NADPH and oxygen, in a variety of semirecombinant cell-free and cell-based NOX2 assays. It inhibited NOX2 in an NADPH competitive manner and was selective over other NOX isoforms, xanthine oxidase, and endothelial nitric oxide synthase enzymes. Following systemic administration in mice, GSK2795039 abolished the production of ROS by activated NOX2 enzyme in a paw inflammation model. Furthermore, GSK2795039 showed activity in a murine model of acute pancreatitis, reducing the levels of serum amylase triggered by systemic injection of cerulein.

INNOVATION AND CONCLUSIONS

GSK2795039 is a novel NOX2 inhibitor that is the first small molecule to demonstrate inhibition of the NOX2 enzyme in vivo.