Allergic rhinitis affects millions globally, causing significant discomfort and reducing the quality of life. This study investigates the metabolic alterations in murine mast cells (MC/9) under allergic rhinitis conditions induced by lipopolysaccharide (LPS) stimulation, employing UHPLC-QTOF-MS-based untargeted and targeted metabolomics. The analysis identified 44 significantly regulated metabolites, including histamine, leukotrienes, prostaglandins, thromboxanes, and ceramides. Key metabolic pathways such as arachidonic acid, histidine, and sphingolipid metabolisms were notably modulated. The study further examined the therapeutic effects of triprolidine and zileuton, demonstrating their capacity to reverse LPS-induced metabolic shifts. Triprolidine primarily modulated histidine and sphingolipid metabolism, while zileuton targeted arachidonic acid and sphingolipid metabolism. These findings underscore the utility of metabolomics analysis in elucidating the complex biochemical pathways involved in allergic rhinitis and highlight the potential of metabolomics for evaluating therapeutic interventions. This study enhances our understanding of mast cell metabolism in allergic responses and provides a robust model for assessing the efficacy of anti-allergic agents, paving the way for more effective treatments.

Measles, hepatitis C, and COVID-19 are significant human diseases caused by RNA viruses. While vaccines exist to prevent infections, there are a small number of currently available therapeutic agents that can effectively treat these diseases after infection occurs. This study explores a new therapeutic strategy using a small molecule designated polyprenyl immunostimulant (PI) to increase innate immune responses and combat viral infections. Using a multi-disciplinary approach, this study quantifies the effects of PI in mice and THP-1 cells using flow cytometry to identify immune phenotypic markers and mass spectroscopy to monitor the metabolomic profiles of immune cells perturbed by PI treatment. The metabolomic studies identified that sphinganine and ceramide, which are precursors of sphingosine-1-phosphate (S1P), were the common metabolites upregulated in THP-1 and mice blood. Sphingosine-1-phosphate can mediate the trafficking of T cells, whereas ceramide can signal the activation and proliferation of T cells, thereby modulating the mammalian host’s immunity. To demonstrate proof-of-principle, a case study was conducted to examine the benefit of administering PI to improve the outcomes of a feline co-infected with two distinct RNA viruses—feline leukemia virus and feline infectious peritonitis virus. Both viruses produce deadly symptoms that closely resemble RNA viruses that infect humans. The results identify quantifiable cellular and metabolic markers arising from PI treatment that can be used to establish a platform measuring the efficacy of PI in modulating the innate immune system.

Twelve-carbon dicarboxylic acid dodecanedioic acid (DODA) has gained recent interest as an alternative nutrient. However, little is known about DODA cellular metabolism. Our study presents novel data on DODA metabolism and its potential role as an alternative carbon substrate. Cells are readily oxidizing DODA as a primary carbon source, yielding acetyl-CoA and succinate and replenishing the Krebs cycle. Furthermore, cells treated with DODA are characterized by a distinct metabolic profile, whereas pathways associated with energy metabolism are highly impacted. We also found that DODA administration alters carbon substrate preferences for respiration, restricting overreliance on one substrate as a primary fuel. Consequently, by rebalancing cellular energy metabolism, DODA as a supplemental carbon source may have significant therapeutic implications in conditions that are characterized by energy deficiency and metabolic inflexibility.

The integrated stress response (ISR) is a cellular defense mechanism activated under stress conditions. When the ISR is activated, it slows the production of proteins, the building blocks that cells need to function. Trans-integrated stress response inhibitor (trans-ISRIB) is a compound that can reverse the effects of ISR activation, showing promise for treating neurodegenerative diseases. The preclinical and clinical evaluation of trans-ISRIB necessitates a reliable analytical method. This study presents the development and validation of an ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the quantitative analysis of trans-ISRIB in human plasma, conforming to the U.S. FDA's guidelines for bioanalytical method validation. The method developed utilizes a liquid-liquid extraction procedure to prepare plasma samples with a spiked internal standard (IS). The extracts containing trans-ISRIB and the IS were dried under nitrogen, reconstituted in the mobile phase, and separated on a Waters XSelect HSS T3 column under isocratic conditions with a mobile phase containing 0.1 % acetic acid in 70 % methanol aqueous solution at a flow rate of 0.500 mL/min. Detection and quantification were accomplished using a positive electrospray ionization tandem mass spectrometer (ESI⁺-MS/MS) operated in multiple-reaction-monitoring (MRM) mode. The method demonstrated a linear calibration range for trans-ISRIB concentrations from 0.500 to 1.00 x 10³ nM, with high specificity, precision, accuracy, and recovery. This method addresses a significant analytical gap, offering a robust tool for quantifying trans-ISRIB in human plasma. Chemical compounds studied in this article: 2-(4-chlorophenoxy)-N-[4-[[2-(4-chlorophenoxy)acetyl]amino]cyclohexyl]acetamide (trans-ISRIB) (CAS # 1597403-47-8); 2-(4-chlorophenoxy)-N-(2-{[(4-chlorophenoxy)acetyl]amino}ethyl)acetamide (CAS # 327071-30-7).