High-Fat Diet–Wheat Gluten Interactions in HLA-DQ8 Transgenic Mice Yuri Haneishi, Lucia Treppiccione, Vera Rotondi Aufiero, Francesco Maurano, Saya Watanabe, et al. Molecular Nutrition and Food Research, 2025 Unbalanced lipid metabolism contributes to inflammation in several conditions. Gluten, that triggers celiac disease, may also play a role in diseases associated with a high‐fat diet (HFD). Our aim was to investigate the interplay between gluten and HFD in HLA‐DQ8 (DQ8) transgenic mice, a model of gluten sensitivity. DQ8 mice were fed the gluten‐free diet, the HFD, or the HFD containing 8% gluten (HFD + G) for 12 or 23 weeks. Clinical parameters, liver and intestinal histology, immune parameters were assessed. Twelve weeks of HFD increased body and white adipose tissue weight and reduced glucose tolerance in male DQ8 mice. Gluten increased hyperinsulinemia and lipid accumulation in liver; interferon gamma (IFN‐γ) and interleukin‐10 (IL‐10) transcripts were higher in liver of HFD + G‐fed mice. IL‐1β, tumor necrosis factor‐α (TNF‐α), IFN‐γ, and IL‐10 mRNAs increased in the small intestine of HFD + G‐fed mice. However, gliadin‐specific immunity and alterations of the intestinal architecture were not induced. Feeding HFD + G for 23 weeks attenuated the gluten effect. A synergic effect between gluten and HFD after 12 weeks was found, which was instrumental to alter specific metabolic and immune functions in DQ8 mice. These findings provide new insights useful to dissect the association between obesity and gluten sensitivity.
Data-Independent Acquisition Coupled with Electron-Activated Dissociation for In-Depth Structure Elucidation of the Fatty Acid Ester of Hydroxy Fatty Acids Yuto Kurizaki, Yuki Matsuzawa, Mikiko Takahashi, Hiroaki Takeda, Mayu Hasegawa, et al. Analytical Chemistry, 2025 Fatty acid esters of hydroxy fatty acid (FAHFAs) are a biologically important class of lipids known for their anti-inflammatory and antidiabetic effects in animals. The physiological activity of FAHFAs varies depending on the length of the carbon chain, number and position of double bonds (DBs), and position of the hydroxyl (OH) group. Moreover, gut bacteria produce FAHFAs with more diverse structures than those produced by the host, which necessitates a FAHFA-lipidomics approach grasping their diverse structures to fully understand the physiological and metabolic significance of FAHFAs. In this study, we developed a methodology for the in-depth structural elucidation of FAHFAs. First, FAHFAs were enriched by using a solid-phase extraction (SPE) system coated with titanium and zirconium dioxide, which separated these analytes from neutral lipids and phospholipids. The fractionated metabolites were then derivatized using N,N-dimethylethylenediamine (DMED) to facilitate FAHFA detection in the positive ion mode of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) system. A data-independent acquisition technique known as sequential window acquisition of all theoretical mass spectra (SWATH-DIA) was used to collect sequential MS/MS spectra of the DMED-derivatized fatty acid metabolites. Structural elucidation was based on fragment ions generated by electron-activated dissociation (EAD). DMED-FAHFAs were annotated using the newly updated MS-DIAL program, and FAHFA isomers were quantified using the MRMPROBS program, which quantifies lipids based on SWATH-MS/MS chromatograms. This procedure was applied to profile the FAHFAs present in mouse fecal samples, characterizing seven structures at the molecular species level, 63 structures at the OH-position-resolved level, and 15 structures at both the DB- and OH-position-resolved levels, using the MS-DIAL program. In the MRMPROBS analysis, 2OH and 3OH hydroxy fatty acids with more than 20 carbon atoms were predominantly expressed, while 5OH-13OH hydroxy fatty acids with 16 or 18 carbon atoms were the major components, abundant at positions 5, 7, 9, and 10. Furthermore, age-related changes in FAHFA isomers were also observed, where FAHFA 4:0/2O(FA 26:0) and FAHFA 16:0/10O(FA 16:0) significantly increased with age. In conclusion, our study offers a novel LC-SWATH-EAD-MS/MS technique with the update of computational MS to facilitate in-depth structural lipidomics of FAHFAs.
Acidipropionibacterium acidipropionici, a propionate-producing bacterium, contributes to GPR41 signaling and metabolic regulation in high-fat diet-induced obesity in mice Junki Miyamoto, Yuna Ando, Mayu Yamano, Akari Nishida, Kota Murakami, et al. Frontiers in Nutrition, 2025 Obesity is a major healthcare problem worldwide and is induced by excess energy intake, resulting in gut microbial composition and microbial diversity changes. Through fermentation of dietary fibers, short-chain fatty acids (SCFAs) act as host energy sources and signaling molecules via G protein-coupled receptors such as GPR41. Acidipropionibacterium acidipropionici is widely used in many applications; however, in vivo studies on the beneficial effect of A. acidipropionici via propionate production and host energy homeostasis are unclear. Therefore, this study aimed to investigate the beneficial metabolic effects of A. acidipropionici by focusing on GPR41 signaling in a high-fat diet (HFD)-induced obesity mouse model. Here, we demonstrated that A. acidipropionici OB7439 improved host metabolism in HFD-induced obesity in mice. The intake of A. acidipropionici OB7439 improved metabolism in HFD-induced obese mice by increasing propionate production, regulating glucose tolerance, and inhibiting hepatic inflammation via GPR41 signaling. Our findings shed light on the potential of using A. acidipropionici OB7439 as an SCFA producer for the prevention and treatment of metabolic disorders. Based on these results, we suggest that A. acidipropionici may be a potential therapeutic bacterium that inhibits obesity and modulates the gut microbial community.
MS-DIAL 5 multimodal mass spectrometry data mining unveils lipidome complexities Hiroaki Takeda, Yuki Matsuzawa, Manami Takeuchi, Mikiko Takahashi, Kozo Nishida, et al. Nature Communications, 2024 Lipidomics and metabolomics communities comprise various informatics tools; however, software programs handling multimodal mass spectrometry (MS) data with structural annotations guided by the Lipidomics Standards Initiative are limited. Here, we provide MS-DIAL 5 for in-depth lipidome structural elucidation through electron-activated dissociation (EAD)-based tandem MS and determining their molecular localization through MS imaging (MSI) data using a species/tissue-specific lipidome database containing the predicted collision-cross section values. With the optimized EAD settings using 14 eV kinetic energy, the program correctly delineated lipid structures for 96.4% of authentic standards, among which 78.0% had the sn-, OH-, and/or C = C positions correctly assigned at concentrations exceeding 1 μM. We showcased our workflow by annotating the sn- and double-bond positions of eye-specific phosphatidylcholines containing very-long-chain polyunsaturated fatty acids (VLC-PUFAs), characterized as PC n-3-VLC-PUFA/FA. Using MSI data from the eye and n-3-VLC-PUFA-supplemented HeLa cells, we identified glycerol 3-phosphate acyltransferase as an enzyme candidate responsible for incorporating n-3 VLC-PUFAs into the sn1 position of phospholipids in mammalian cells, which was confirmed using EAD-MS/MS and recombinant proteins in a cell-free system. Therefore, the MS-DIAL 5 environment, combined with optimized MS data acquisition methods, facilitates a better understanding of lipid structures and their localization, offering insights into lipid biology.
High Fat Diet–Wheat Gliadin Interaction and its Implication for Obesity and Celiac Disease Onset: In Vivo Studies Yuri Haneishi, Lucia Treppiccione, Francesco Maurano, Diomira Luongo, Junki Miyamoto, et al. Molecular Nutrition and Food Research, 2024 The intestinal immune system plays a crucial role in obesity and insulin resistance. An altered intestinal immunity is associated with changes to the gut microbiota, barrier function, and tolerance to luminal antigens. Lipid metabolism and its unbalance can also contribute to acute and chronic inflammation in different conditions. In celiac disease (CD), the serum phospholipid profile in infants who developed CD is dramatically different when compared to that of infants at risk of CD not developing the disease. In a mouse model of gluten sensitivity, oral wheat gliadin challenge in connection with inhibition of the metabolism of arachidonic acid, an omega‐6 polyunsaturated fatty acid, specifically induces the enteropathy. Recent evidence suggests that gluten may play a role also for development of life‐style related diseases in populations on a high fat diet (HFD). However, the mechanisms behind these effects are not yet understood. Exploratory studies in mice feed HFD show that wheat gliadin consumption affects glucose and lipid metabolic homeostasis, alters the gut microbiota, and the immune cell profile in liver.
