Wheat Amylase Trypsin Inhibitors Aggravate Intestinal Inflammation Associated with Celiac Disease Mediated by Gliadin in BALB/c Mice

Dietary methionine restriction restores wheat gluten-induced celiac-associated small intestine damage in association with affecting butyric acid production by intestinal flora

Methionine restriction has received some attention in recent years as a novel mode of dietary intervention. Our previous study found that methionine restriction could inhibit the celiac toxic effects of wheat gluten in an in vitro model. However, the role of methionine restriction in gluten-induced celiac intestinal damage remains unclear. The aim of this study was to explore whether dietary methionine restriction could suppress the celiac toxic effects of gluten in an in vivo model, thereby mitigating intestine damage. This study systematically investigated the effects of dietary methionine restriction on celiac characteristic indicators such as symptoms, small intestine damage, and intestinal TG2 and IL-15 expression in a gluten-induced C57BL/6 mouse model. The availability of dietary methionine restriction in different ages (adolescent and adult) was also evaluated. Moreover, mouse cecum contents were assayed and co-analyzed for the metagenome of intestinal flora and target short-chain fatty acid metabolomics, with the goal of further exploring and elucidating critical pathways by which dietary methionine restriction plays a role. We discovered that dietary methionine restriction could effectively ameliorate the gluten-induced celiac-associated small intestine damage by modulating intestinal flora to inhibit butyric acid production. Specifically, dietary methionine restriction could inhibit butyric acid production with the help of s_CAG-485 sp002493045 and s_CAG-475 sp910577815, which in turn affected the mitochondrial function within the intestinal epithelial cells to assist in the repair of intestine damage. This study might provide new insights into modulating dietary patterns to mitigate intestinal damage in celiac disease and the production of novel gluten-free products.

Oroxin B Resembles Bisoprolol in Attenuating Beta1-Adrenergic Receptor Autoantibody-Induced Atrial Remodelling via the PTEN/AKT/mTOR Signalling Pathway

Beta1-adrenergic receptor autoantibodies (β1-AAbs) promote atrial remodelling and ultimately lead to the development of atrial fibrillation (AF). Oroxin B is a natural flavonoid glycoside with a variety of biological activities, including anti-inflammatory and autophagy-promoting effects, and has therapeutic benefits for a variety of diseases. The aim of this study was to investigate the potential therapeutic role of Oroxin B in the development of β1-AAb-induced atrial fibrillation and to elucidate the underlying mechanisms involved. We established a rat model of β1-AAb-induced atrial fibrillation via active immunisation. The first stage was divided into three groups: the control group, the β1-AAb group and the β1-AAb + bisoprolol group. The second stage was divided into three groups: the control group, the β1-AAb group and the β1-AAb + Oroxin B group. Serum levels of β1-AAbs, atrial tissue levels of cyclic monophosphate (cAMP), atrial electrophysiological parameters, cardiac structure and function, mitochondrial structure, autophagy levels, cardiomyocyte apoptosis and myocardial fibrosis were examined. The results showed that bisoprolol, a β1-blocker, improved β1-AAb-induced atrial electrical remodelling, reduced atrial collagen deposition, ameliorated the increase in LAD and regulated the balance of autophagy and apoptosis in atrial myocytes through the PTEN/AKT/mTOR signalling pathway. Oroxin B, a PTEN agonist, can improve the impairment of autophagy homeostasis and apoptosis in atrial tissue by activating the PTEN/AKT/mTOR signalling pathway, thereby improving atrial structure and electrical remodelling. Moreover, Oroxin B may play a therapeutic role in β1AAb-induced atrial fibrillation. In conclusion, our results demonstrate the potential therapeutic role of Oroxin B in β1AAb-induced atrial fibrillation and the underlying mechanisms, suggesting that Oroxin B may be an effective antiarrhythmic medication.

Detoxification Mechanism and the Impact of Transamidation-Modified Gliadin on Celiac-Based Gluten Sensitivity: The Potential of Unlocking Gluten Tolerance in Functional Food

Transamidation of gliadin under reducing conditions has shown promise in mitigating celiac disease-related gluten toxicity. However, comprehensive evaluation in both in vitro and in vivo models is crucial. This study investigated the effects of transamidated gliadin (GM) on celiac toxicity using Caco-2 cell monolayers, bone marrow-derived dendritic cells (BMDCs), and a BALB/c mouse model. In cellular level, GM mitigated intestinal damage compared to unmodified gliadin and stimulated a less pronounced pro-inflammatory response, suggesting a reduced activation of the T-cell-mediated immune system. In vivo, the GM group displayed lower levels of pro-inflammatory factors and less pronounced Th1/Th2 imbalance compared to the unmodified gliadin group. Notably, the GM also improved the balance of the intestinal microbiome. In brief, GM exhibited significantly reduced celiac toxicity in both cellular and animal models that mimics the intestinal environment of celiac disease. These findings suggest that transamidation treatment holds potential as a safer alternative strategy to lower the toxicity of wheat gliadin/wheat flour, potentially paving the way for developing modified gluten-based foods with desirable texture or ingredients as a nutritional enhancer or structure improver, benefiting individuals with specific needs.

Molecular Cloning, Prokaryotic Expression, and Immunological Characterization of β-Enolase from Grass Carp (Ctenopharyngodon idella)

β-Enolase is a cross-allergen commonly found in fungi, plants, and aquatic products. Although studies on the allergenicity of fish enolase have been reported in recent years, they are still limited to a few species of marine fish. Therefore, the detection of freshwater fish in the food industry requires more studies of the molecular characterization as well as the allergenicity of enolase. In this study, the nucleotide sequence of β-enolase from grass carp was obtained by molecular cloning technology. Structural domain analysis showed that it contained the characteristic structural domains of the enolase superfamily, and homology analysis indicated that enolases are highly conserved evolutionarily. Recombinant β-enolase was obtained by prokaryotic expression, and its allergenicity was assessed by β-enolase-sensitized mice, which confirmed the ability of β-enolase to trigger an allergic response and cause a rise in Th1 and Th2 immune responses in mice. These results suggest that β-enolase could be used as a characterizing substance for the detection of fish allergens in the food industry as well as the preparation of drugs for allergy-related studies.

Quercetin ameliorates celiac-related intestinal inflammation caused by wheat gluten through modulating oxidative stress, Th1/Th2/Treg balance, and intestinal microflora structure

Celiac disease is a chronic inflammatory autoimmune disease of the small bowel, and about 1% of the world's population is afflicted with celiac disease. To date, the most efficient treatment option is that the patient is required to strictly follow a gluten-free diet for their entire life, but it's difficult to adhere to and can lead to new nutritional imbalances, making it urgent to find novel nutritional interventions. Our aim was to explore the effects of nutritional intervention with quercetin on the celiac toxic effects of wheat gluten. This study systematically assessed the regulatory roles of quercetin on intestinal oxidative damage, immune response, inflammatory damage, and intestinal microflora dysbiosis in celiac disease by utilizing the established celiac in vitro and in vivo models induced by gluten. We discovered that quercetin could play a crucial role in intervening in celiac pathogenesis, not only owing to its antioxidant properties, but also because it modulates immune cell function and the intestinal microflora structure, particularly the regulation of Th1/Th2/Treg immune cell subpopulations and their functions, inhibition of the abundance of celiac disease marker flora such as Clostridium_celatum and Bacteroides_acidifaciens, and upregulation of the abundance of beneficial flora such as Butyricoccus_pullicaecorum and Bifidobacterium_longum, which ultimately worked together to ameliorate the celiac-related intestinal inflammation triggered by gluten. This study might provide new insights into the regulation of gut immunity and intestinal microflora homeostasis, as well as the potential application of quercetin in celiac disease.

Does sourdough bread provide clinically relevant health benefits?

During the last decade, scientific interest in and consumer attention to sourdough fermentation in bread making has increased. On the one hand, this technology may favorably impact product quality, including flavor and shelf-life of bakery products; on the other hand, some cereal components, especially in wheat and rye, which are known to cause adverse reactions in a small subset of the population, can be partially modified or degraded. The latter potentially reduces their harmful effects, but depends strongly on the composition of sourdough microbiota, processing conditions and the resulting acidification. Tolerability, nutritional composition, potential health effects and consumer acceptance of sourdough bread are often suggested to be superior compared to yeast-leavened bread. However, the advantages of sourdough fermentation claimed in many publications rely mostly on data from chemical and in vitro analyzes, which raises questions about the actual impact on human nutrition. This review focuses on grain components, which may cause adverse effects in humans and the effect of sourdough microbiota on their structure, quantity and biological properties. Furthermore, presumed benefits of secondary metabolites and reduction of contaminants are discussed. The benefits claimed deriving from in vitro and in vivo experiments will be evaluated across a broader spectrum in terms of clinically relevant effects on human health. Accordingly, this critical review aims to contribute to a better understanding of the extent to which sourdough bread may result in measurable health benefits in humans.

Peroxiredoxins and Hypoxia-Inducible Factor-1α in Duodenal Tissue: Emerging Factors in the Pathophysiology of Pediatric Celiac Disease Patients

Celiac disease (CD) is an autoimmune enteropathy. Peroxiredoxins (PRDXs) are powerful antioxidant enzymes having an important role in significant cellular pathways including cell survival, apoptosis, and inflammation. This study aimed at investigating the expression levels of all PRDX isoforms (1-6) and their possible relationships with a transcription factor, HIF-1α, in the small intestinal tissue samples of pediatric CD patients. The study groups consisted of first-diagnosed CD patients (n = 7) and non-CD patients with functional gastrointestinal tract disorders as the controls (n = 7). The PRDXs and HIF-1α expression levels were determined by using real-time PCR and Western blotting in duodenal biopsy samples. It was observed that the mRNA and protein expression levels of PRDX 5 were significantly higher in the CD patients, whereas the PRDX 1, -2, and -4 expressions were decreased in each case compared to the control group. No significant differences were detected in the PRDX 3 and PRDX 6 expressions. The expression of HIF-1α was also significantly elevated in CD patients. These findings indicate, for the first time, that PRDXs, particularly PRDX 5, may play a significant role in the pathogenesis of CD. Furthermore, our results suggest that HIF-1α may upregulate PRDX-5 transcription in the duodenal tissue of CD.

Absolute and relative quantitation of amylase/trypsin-inhibitors by LC-MS/MS from wheat lines obtained by CRISPR-Cas9 and RNAi

Quantitation of wheat proteins is still a challenge, especially regarding amylase/trypsin-inhibitors (ATIs). A selection of ATIs was silenced in the common wheat cultivar Bobwhite and durum wheat cultivar Svevo by RNAi and gene editing, respectively, in order to reduce the amounts of ATIs. The controls and silenced lines were analyzed after digestion to peptides by LC-MS/MS with different approaches to evaluate changes in composition of ATIs. First, a targeted method with stable isotope dilution assay (SIDA) using labeled peptides as internal standards was applied. Additionally, four different approaches for relative quantitation were conducted, in detail, iTRAQ labeled and label free quantitation (LFQ) combined with data dependent acquisition (DDA) and data independent acquisition (DIA). Quantitation was performed manually (Skyline and MASCOT) and with different proteomics software tools (PLGS, MaxQuant, and PEAKS X Pro). To characterize the wheat proteins on protein level, complementary techniques as high-performance liquid chromatography (HPLC) and gel electrophoresis were performed. The targeted approach with SIDA was able to quantitate all ATIs, even at low levels, but an optimized extraction is necessary. The labeled iTRAQ approach revealed an indistinct performance. LFQ with low resolution equipment (IonTrap) showed similar results for major ATIs, but low abundance ATIs as CM1, were not detectable. DDA measurements with an Orbitrap system and evaluation using MaxQuant showed that the relative quantitation was dependent on the wheat species. The combination of manual curation of the MaxQuant search with Skyline revealed a very good performance. The DIA approach with analytical flow found similar results compared to absolute quantitation except for some minor ATIs, which were not detected. Comparison of applied methods revealed that peptide selection is a crucial step for protein quantitation. Wheat proteomics faces challenges due to the high genetic complexity, the close relationship to other cereals and the incomplete, redundant protein database requiring sensitive, precise and accurate LC-MS/MS methods.