Gluten Immunogenic Peptides as Standard for the Evaluation of Potential Harmful Prolamin Content in Food and Human Specimen

Gluten is a complex mixture of storage proteins in cereals like wheat, barley, and rye. Prolamins are the main components of gluten. Their high content in proline and glutamine makes them water-insoluble and difficult to digest in the gastrointestinal tract. Partial digestion generates peptide sequences which trigger immune responses in celiac and gluten-sensitive patients. Gluten detection in food is challenging because of the diversity, in various food matrices, of protein proportions or modifications and the huge number of immunogenic sequences with differential potential immunoactivity. Attempts to develop standard reference materials have been unsuccessful. Recent studies have reported the detection of a limited number of dominant Gluten Immunogenic Peptides (GIP) that share similarities to epitopes presented in the α-gliadin 33-mer, which showed to be highly proteolytic resistant and is considered to be the most immunodominant peptide within gluten in celiac disease (CD). GIP were detectable and quantifiable in very different kind of difficult to analyze food, revealing the potential immunogenicity by detecting T-cell activity of celiac patients. But GIP were also found in stool and urine of celiac patients on a supposedly gluten-free diet (GFD), showing the capacity to resist and be absorbed and excreted from the body, providing the first simple and objective means to assess adherence to the GFD. Methods to specifically and sensitively detect the most active GIP in food and biological fluids are rational candidates may use similar analytical standard references for determination of the immunopathological risk of gluten exposure in gluten-related diseases.España, MINECO AGL2013-48946-CEspaña, Ministerio de Ciencia, Innovación y Universidades y Corporación Tecnológica de Andalucía (CTA

Effector specificity mutants of the transcriptional activator NahR of naphthalene degrading Pseudomonas define protein sites involved in binding of aromatic inducers

This work reports a genetic analysis of the interactions between NahR, the LysR-type regulator of the NAH operons for biodegradation of naphthalene in Pseudomonas, and its aromatic effectors. Six mutants encoding NahR variants responsive to salicylate analogs such as benzoate, which is not an inducer for the wild type regulator, were isolated with a polymerase chain reactionbased saturation mutagenesis protocol. Most mutants displaying a specific change of effector profile bore single amino acid substitutions within a short protein segment of 60 residues located at the central portion of the NahR sequence. Some of the protein variants exhibited an increased affinity for salicylate and also for otherwise suboptimal effectors, with apparent Ks * values 5–100-fold lower than those of the wild type NahR protein. In addition, all mutants were activated by inducers bearing novel substituents at positions 1 or 2 of the aromatic ring and displayed also an enhanced tolerance to changes at positions 3 and 4. Correlation between mutations in NahR and the structures of the new effectors suggested that protein sites Met116, Arg132, Asn169, and Arg248 are involved in effector recognition and binding during the earlier steps of the process leading to transcriptional activation of cognate NAH promoter

Quality of Life in Teenagers and Adults With Coeliac Disease: From Newly Spanish Coeliac Disease Questionnaire Validation to Assessment in a Population-Based Study

Background: Coeliac disease (CD) is an immune-mediated systemic disorder elicited by the ingestion of gluten in genetically predisposed individuals. Gluten restriction in CD sufferers leads to numerous limitations in various aspects of daily life and can significantly impact the quality-of-life (QoL). The specific and widely used Coeliac Disease Questionnaire (CDQ) is an excellent tool to evaluate QoL in patients with CD, assessing physical, psychological, and social domains. This questionnaire is unavailable in Spain. Therefore, our study is the first to translate, culturally adapt, validate, and apply the Spanish version of CDQ to a representative sample of Spanish teenagers and adults with CD. Methods: A total of 153 CD participants with biopsy-proven and self-reported gluten-free adherence were included in the cross-sectional study, which included four stages: (1) translation and retranslation of the French CDQ version into Spanish; (2) cultural adaptation and semantic evaluation; (3) CDQ validation through the internal consistency determination and reproducibility of the QoL; and (4) application of the questionnaire to Spanish teenagers and adults with CD and estimation of QoL using EQ-5D. Results: The internal consistency and test–retest reliability of the Spanish CDQ were satisfactory and no ceiling or floor effects were detected. Significant correlations were identified between the CDQ scales, and the instrument for validation covering similar dimensions of the QoL was identified. The mean CDQ total score was 131.03 ± 24.1, and the social domain had the highest rating. There was no correlation between the time spent on a gluten-free diet and QoL. A significantly higher QoL score was reported among males and adolescents in the 15–17 age groups. Conclusion: The newly Spanish CDQ is an appropriate tool to assess the QoL of the teenager and adult patients with CD. This study highlights the importance of identifying the affected scales to address actions to reduce the impact of the gluten-free diet burden of the coeliac patients and maintain public health regulations that support patients with chronic diseases such as CDCentro para el Desarrollo Tecnologico Industrial 20/0112Corporación Tecnológica de Andalucía 20/011

Translational and structural requirements of the early nodulin gene enod40, a short-open reading frame-containing RNA, for elicitation of a cell-specific growth response in the alfalfa root cortex

A diversity of mRNAs containing only short open reading frames (sORF-RNAs; encoding less than 30 amino acids) have been shown to be induced in growth and differentiation processes. The early nodulin gene enod40, coding for a 0.7-kb sORF-RNA, is expressed in the nodule primordium developing in the root cortex of leguminous plants after infection by symbiotic bacteria. Ballistic microtargeting of this gene into Medicago roots induced division of cortical cells. Translation of two sORFs (I and II, 13 and 27 amino acids, respectively) present in the conserved 5* and 3* regions of enod40 was required for this biological activity. These sORFs may be translated in roots via a reinitiation mechanism. In vitro translation products starting from the ATG of sORF I were detectable by mutating enod40 to yield peptides larger than 38 amino acids. Deletion of a Medicago truncatula enod40 region between the sORFs, spanning a predicted RNA structure, did not affect their translation but resulted in significantly decreased biological activity. Our data reveal a complex regulation of enod40 action, pointing to a role of sORF-encoded peptides and structured RNA signals in developmental processes involving sORF-RNA

Update on nutritional aspects of gluten-free diet in celiac patients

A strict gluten - free diet is the only currently available therapeutic treatment for patients with celiac disease, an autoimmune disorder of the small intestine associated with a permanent intolerance to gluten proteins. In recent years, the dramatically prompted changes in the dietary habit of an increasingly large population (celiac disease, non - celiac gluten sensitivit y and gluten allergy) has resulted in rising demands for gluten - free products. Before starting gluten - free diet, alteration in intestinal absorption capacity of celiac patients involves deficiencies of nutrients, vitamins and dietary minerals. The habitual poor gluten - free food choices in addition to inherent deficiencies in the gluten - free diet of diagnosed celiac patients may relate with dietary inadequacies. Therefore dietary assessment and counseling at the time of celiac disease diagnosis and ongoing c are are crucial as well as fortification of gluten - free foods also need to be considered. This article reviews the nutritional aspects of gluten - free diet in celiac patients and provides an up - date of dietetic recommendations to correct these deficiencies and to ensure optimum gluten - free diet compliance

Alternative grains as potential raw material for gluten– free food development in the diet of celiac and gluten– sensitive patients

Celiac disease is an autoimmune disorder resulting from gluten intolerance and is based on a genetic predisposition. Gluten is a protein composite found in the cereals wheat, rye, barley and certain oat varieties. A strict gluten-free diet is the only currently available therapeutic treatment for patients with celiac disease. Rising demands for gluten-free products parallels the apparent or real increase in celiac disease, non-celiac gluten sensitivity and gluten allergy. However, gluten removal results in major problems for bakers, and currently, many gluten-free products available on the market are of low quality exhibiting poor mouthfeel and flvor. Thus, an increasing trend in research is focusing on the application of alternative grains potentially healthy to elaborate gluten-free products. A promising area is the use of cereals (rice, corn and sorghum), minor cereals (fonio, teff, millet and job’s tears) or pseudocereals such as amaranth, buckwheat, quinoa. Nevertheless, commercialization of these products is still quite limited. The aim of this work is to review recent advances in research about the nutritional quality and potential health benefis of alternative grains tolerated by patients with gluten related pathologies.Junta de Andalucía P09AGR-478

Metalloadsorption by Escherichia coli cells displaying yeast and mammalian metallothioneins anchored to the outer membrane protein LamB

Yeast (CUP1) and mammalian (HMT-1A) metallothioneins (MTs) have been efficiently expressed in Escherichia coli as fusions to the outer membrane protein LamB. A 65-amino-acid sequence from the CUP1 protein of Saccharomyces cerevisiae (yeast [Y] MT) was genetically inserted in permissive site 153 of the LamB sequence, which faces the outer medium. A second LamB fusion at position 153 was created with 66 amino acids recruited from the form of human (H) MT that is predominant in the adipose tissue, HMT-1A. Both LamB153- YMT and LamB153-HMT hybrids were produced in vivo as full-length proteins, without any indication of instability or proteolytic degradation. Each of the two fusion proteins was functional as the port of entry of lambda phage variants, suggesting maintenance of the overall topology of the wild-type LamB. Expression of the hybrid proteins in vivo multiplied the natural ability of E. coli cells to bind Cd21 15- to 20-fold, in good correlation with the number of metal-binding centers contributed by the MT moiety of the fusion

Role of oats in celiac disease

A gluten-free diet is currently the only effective means of treating individuals with celiac disease. Such a diet enables celiac patients to control their symptoms and avoid various complications associated with this condition. However, while the quality of gluten-free foods has significantly improved during recent decades, maintenance of a gluten-free diet does not necessarily ensure adequate nutritional intake. Because oats are an important source of proteins, lipids, vitamins, minerals, and fibre, their inclusion in a gluten-free diet might improve the nutritional status of a celiac patient. Although oats are included in the list of gluten-free ingredients specified in European regulations, their safety when consumed by celiac patients remains debatable. Some studies claim that pure oats are safe for most celiac people, and contamination with other cereal sources is the main problem facing people with this disease. However, it is necessary to consider that oats include many varieties, containing various amino acid sequences and showing different immunoreactivities associated with toxic prolamins. As a result, several studies have shown that the immunogenicity of oats varies depending on the cultivar consumed. Thus, it is essential to thoroughly study the variety of oats used in a food ingredient before including it in a gluten-free diet

Determination of gluten immunogenic peptides for the management of the treatment adherence of celiac disease: A systematic review

BACKGROUND Gluten is a complex mixture of proteins with immunogenic peptide sequences triggering the autoimmune activity in patients with celiac disease (CeD). Gluten immunogenic peptides (GIP) are resistant to gastrointestinal digestion and are then excreted via the stool and urine. Most common detection methods applied in the follow-up visits for CeD patients such as serology tests, dietetic interviews, questionnaires, and duodenal biopsy have been proved to be inefficient, invasive, or inaccurate for evaluating gluten-free diet (GFD) compliance. Determination of excreted GIP in stool and urine has been developed as a non-invasive, direct, and specific test for GFD monitoring. AIM To summarize published literature about the clinical utility of GIP determination in comparison to the tools employed for GFD monitoring. METHODS PubMed and Web of Science searches were performed using the keywords “gluten immunogenic peptides” or “gluten immunogenic peptide” and a combination of the previous terms with “feces”, “stools”, “urine”, “celiac disease”, “gluten-free diet”, and “adherence” to identify relevant clinical studies published in English and Spanish between 2012 to January 2021. Reference lists from the articles were reviewed to identify additional pertinent articles. Published articles and abstracts reporting the clinical use of GIP determination in stool and/or urine for the follow-up of patients with CeD in comparison with other tools in use were included. Case reports, commentaries, reviews, conference papers, letters, and publications that did not focus on the aims of this review were excluded. RESULTS Total of 15 publications were found that involved the use of GIP determination in stool and/or urine to monitor the adherence to the GFD in comparison to other tools. Studies included both children and adults diagnosed with CeD and healthy volunteers. Overall, these preliminary studies indicated that this novel technique was highly sensitive for the detection of GFD transgressions and therefore could facilitate the follow-up of patients with CeD. Tools identified in this work included the CeD-specific serology, dietetic questionnaires, symptomatology, and the duodenal biopsy. Review of the literature revealed that the rates of GFD adherence may vary between 30%-93% using either stool or urine GIP determination, 49%-96% by the serology, 59%-94% using the dietetic questionnaires, 56%-95% by the reported symptoms and 44%-76% with the duodenal biopsy. In addition, the association between the different methods and histological abnormalities (Marsh II-III) was found to be 33%-100% for GIP determination (stool and urine), 25%-39% for CeD-specific serology, 3%-50% for dietetic questionnaires, and 22%-28% for the symptomatology. CONCLUSION Excreted GIP detection is the precise approach for determining voluntary or involuntary gluten consumption in CeD patients preventing future complications arising from gluten exposure