The immunopathogenesis of celiac disease reveals possible therapies beyond the gluten-free diet

Mitigation of Gliadin-Induced Inflammation and Cellular Damage by Curcumin in Human Intestinal Cell Lines

Wheat is a major diet from many years; apart from its nutritious value, the wheat protein gliadin is responsible for many inflammatory diseases like celiac disease (CD), and non-celiac gluten sensitivity (NCGS). In this study, the gliadin-induced inflammation and associated cellular damage along with the protective role of curcumin was evaluated using human intestinal cell lines (HCT-116 and HT-29) as a model. Cells were cultured and exposed to 160 μg/ml of gliadin, 100 μM H₂O₂, and 10 μM curcumin (3 h pretreatment) followed by the assessment of inflammation. Spectrophotometric methods, real-time-PCR, ELISA, Western blotting, and confocal microscopy techniques were used to assess inflammatory markers such as advanced oxidation protein products (AOPPs) level, activity of myeloperoxidase (MPO) and NADPH oxidase (NOX), cytokines, and cell damage markers. The results show that gliadin increases the AOPPs level and the activity of MPO and NOX expression. It enhances inflammation by increasing expression of pro-inflammatory cytokines, altered expression of anti-inflammatory, and regulatory cytokines. It exacerbates the cellular damage by increasing MMP-2 and 9 and decreasing integrin α and β expression. Gliadin promotes disease pathogenesis by inducing the inflammation and cellular damage which further alter the cellular homeostasis. The pretreatment of curcumin counteracts the adverse effect of gliadin and protect the cells via diminishing the inflammation and help the cell to regain the cellular morphology suggesting phytochemical-based remedial interventions against wheat allergies.

Thiol-disulfide homeostasis in children with celiac disease

BACKGROUND

Toxic gliadin peptide damages enterocytes in celiac disease by causing oxidative stress. Thiols are organic compounds that defend against oxidative stress. This study aimed to investigate the changes in thiol-disulfide homeostasis in children with celiac disease.

METHODS

The study included patients with celiac disease, children diagnosed with functional gastrointestinal disorders, and healthy children. Patients' serum native and total thiol-disulfide amounts, disulfide/total thiol percentage ratios, disulfide / native thiol percentage ratios, and native thiol/total thiol percentage ratios were measured.

RESULTS

The study involved 172 children, of whom 90 (52.3%) were girls. The mean participant age was 8.6 ± 4.2 years. A total of 59 (34.3%) children had celiac disease, 56 (32.6%) had functional gastrointestinal disorders, and 57 (33.1%) were healthy. The total thiol and disulfide levels of patients with celiac disease (305 ± 87 μmol/L and 25 ± 15 μmol/L, respectively) were significantly lower than those of healthy children (349 ± 82 μmol/L and 40 ± 15 μmol/L, respectively) (P = 0.006 and P < 0.001, respectively). Native and total thiol levels (226 ± 85 μmol/L and 279 ± 99 μmol/L, respectively) in patients with celiac disease who consumed a gluten-containing diet were significantly lower than those of patients who consumed a gluten-free diet (278 ± 64 μmol/L and 327 ± 69 μmol/L, respectively) (P = 0.017 and P = 0.041, respectively).

CONCLUSIONS

Thiol-disulfide homeostasis, an important antioxidant defense component of the gastrointestinal system, is disrupted in children with celiac disease. A gluten-free diet helped partially ameliorate this decline.

Differential regulation of claudin-2 and claudin-15 expression in children and adults with malabsorptive disease

Intestinal Na+-nutrient cotransport depends on claudin-2 and claudin-15 mediated Na+ recycling. Expression of these proteins is coordinately regulated during postnatal development. While expression of claudin-2 and claudin-15 has been studied in inflammatory bowel disease (IBD) and celiac disease (CD), it has not been assessed in other malabsorptive diseases, and no reports have compared expression in children and adults. We used quantitative immunofluorescence microscopy to assess claudin-2 and claudin-15 expression in duodenal biopsies from children and adults with malabsorptive disease and healthy controls. Consistent with previous work in rodents, claudin-2 expression in healthy children was markedly greater, and claudin-15 expression was less, than that in adults. Claudin-2 expression was increased in adults with CD and downregulated in children with graft-versus-host disease (GVHD). In contrast, claudin-15 expression was reduced in adults with GVHD and common variable immunodeficiency (CVID). These data show that one of the two Na+/water pore-forming claudins is upregulated in CD and downregulated in GVHD and CVID. The specific claudin whose expression changes, however, reflects the age of the patient (child or adult). We conclude that contributions of claudin-2 and claudin-15 to pathophysiology of and responses to diarrhea in children and adults with GVHD and CVID differ from those in CD and IBD.

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.

Clinical intervention using Bifidobacterium strains in celiac disease children reveals novel microbial modulators of TNF-α and short-chain fatty acids

BACKGROUND & AIMS

Celiac disease (CD) is an immune-mediated systemic disease, caused by ingestion of gluten in genetically predisposed individuals. Gut microbiota dysbiosis might play a significant role in pathogenesis of chronic enteropathies and its modulation can be used as an intervention strategy in CD as well. In this study, we aimed to identify correlations between fecal microbiota, serum tumor necrosis factor alpha (TNF-α) and fecal short-chain fatty acids (SCFAs) in healthy children and children with CD after administration of probiotic Bifidobacterium breve BR03 and B632.

METHODS

A double-blind placebo-controlled study enrolled 40 children with CD (CD) and 16 healthy children (HC). CD children were randomly allocated into two groups, of which 20 belonged to the placebo (PL) group and 20 to the Probiotic (PR) group. The PR group received a probiotic formulation containing a mixture of 2 strains, B. breve BR03 (DSM 16604) and B. breve B632 (DSM 24706) in 1:1 ratio for 3 months. Subsequently, for statistical analysis, blood and fecal samples from CD children (on enrolment - T0 and after 3 months, at the end of intervention with probiotic/placebo - T1) and HC children were used. The HC group was sampled only once (T0).

RESULTS

Verrucomicrobia, Parcubacteria and some yet unknown phyla of Bacteria and Archaea may be involved in the disease, indicated by a strong correlation to TNF-α. Likewise, Proteobacteria strongly correlated with fecal SCFAs concentration. The effect of probiotic administration has disclosed a negative correlation between Verrucomicrobia, some unknown phyla of Bacteria, Synergistetes, Euryarchaeota and some SCFAs, turning them into an important target in microbiome restoration process. Synergistetes and Euryarchaeota may have a role in the anti-inflammatory process in healthy human gut.

CONCLUSIONS

Our results highlight new phyla, which may have an important relation to disease-related parameters, CD itself and health.

Understanding Celiac Disease From Genetics to the Future Diagnostic Strategies

Celiac disease (CD) is an autoimmune disorder characterized by the permanent inflammation of the small bowel, triggered by the ingestion of gluten. It is associated with a number of symptoms, the most common being gastrointestinal. The prevalence of this illness worldwide is 1%. One of the main problems of CD is its difficulty to be diagnosed due to the various presentations of the disease. Besides, in many cases, CD is asymptomatic. Celiac disease is a multifactorial disease, HLA-DQ2 and HLA-DQ8 haplotypes are predisposition factors. Nowadays, molecular markers are being studied as diagnostic tools. In this review, we explore CD from its basic concept, manifestations, types, current and future methods of diagnosis, and associated disorders. Before addressing the therapeutic approaches, we also provide a brief overview of CD genetics and treatment.

Immunopathogenesis and therapeutic approaches in pediatric celiac disease

Celiac Disease is an autoimmune enteropathy with increasing incidence worldwide in both adults and children. It occurs as an inflammatory condition with destruction of the normal architecture of villi on consumption of gluten and related protein products found in wheat, barley and rye. However, the exact pathogenesis is not yet fully understood. A gluten-free diet remains the main modality of therapy to date. While some patients continue to have symptoms even on a gluten-free diet, adherence to this diet is also difficult, especially for the children. Hence, there is continued interest in novel methods of therapy and the current research focus is on the promising novel non-dietary modalities of treatment. Here, we critically reviewed the existing literature regarding the pathogenesis of celiac disease in children including the role of in-utero exposure leading to neonatal and infant sensitization and its application for the development of new therapeutic approaches for these patients.

[Gluten migraine]

OBJECTIVE

to study the prevalence of migraine among patients with celiac disease (CD) and clinical features of «gluten migraine» syndrome and to assess the efficacy of gluten diet in its treatment.

MATERIAL AND METHODS

Authors examined 200 CD patients (main group) and 100 patients with reflux esophagitis and without CD (control group). All patients fulfilled the headache diary during three months before the diagnosis of migraine was made and six months during gluten diet.

RESULTS AND CONCLUSION

CD group had migraine syndrome four times more often than the control group (48.5%; p<0.001). In CD group migraine attacks were 2.5 times more frequent than in the control group (р=0.004), but the duration of the attacks was less long, 8 hours in average. The migraine attacks measured by the Visual Analog Scale were less intensive, 55% in average, and had a later onset. The attacks were more frequent in CD patients who were older than 50 years old (р<0.05). The attacks disappeared in 25% of patients with migraine syndrome who were on the gluten diet and the reduction in the intensity and/or frequency of attacks was observed in 38% of patients. We revealed the clear association between migraine syndrome and CD and the high efficacy of gluten diet in the treatment of migraine symptoms.

Administration of Bifidobacterium breve Decreases the Production of TNF-α in Children with Celiac Disease

BACKGROUND

Increasing evidence suggests that not only genetics, but also environmental factors like gut microbiota dysbiosis play an important role in the pathogenesis of celiac disease (CD).

AIM

The aim of our study was to investigate the effect of two probiotic strains Bifidobacterium breve BR03 and B. breve B632 on serum production of anti-inflammatory cytokine interleukin 10 (IL-10) and pro-inflammatory cytokine tumor necrosis factor alpha (TNF-α) in children with CD.

METHODS

The study was a double-blinded, placebo-controlled trial that included 49 children with CD on gluten-free diet (GFD) randomized into two groups and 18 healthy children in the control group. The first group (24 children with CD) daily received B. breve BR03 and B632 (2 × 10(9) colony-forming units) and the second group (25 children with CD) received placebo for 3 months.

RESULTS

TNF-α levels were significantly decreased in the first group after receiving B. breve for 3 months. On follow-up, 3 months after receiving probiotics, TNF-α levels increased again. Children with CD who were on GFD for less than 1 year showed similar baseline TNF-α levels as children who were on GFD for more than 1 year. IL-10 levels were in all groups of patients below detection level.

CONCLUSIONS

Probiotic intervention with B. breve strains has shown a positive effect on decreasing the production of pro-inflammatory cytokine TNF-α in children with CD on GFD.

Environmental enteropathy and malnutrition: do we know enough to intervene?

Environmental enteropathy (EE) is a poorly defined state of intestinal inflammation without overt diarrhea that occurs in individuals exposed over time to poor sanitation and hygiene. It is implicated as a cause of stunting and malnutrition, oral vaccine failure and impaired development in children from low-income countries. The burden on child health of malnutrition alone, which affects 25% of all children and is estimated to result in more than a million deaths annually due to heightened susceptibility to infection, makes urgent a solution to EE. Efforts are thus underway to treat EE even while work continues to identify it through the use of non-invasive biomarkers, and delineate its pathogenesis. A recent study published in BMC Medicine reports the first randomized controlled phase I trial of an anti-inflammatory drug for EE. The aminosalicylate mesalazine was found to be safe in short-term treatment of a small number of severely malnourished children, although efficacy was not established. Whether such treatment trials are premature, or instead a way both to understand and intervene in EE, is the focus of this article. Please see related article: http://www.biomedcentral.com/1741-7015/12/133.

Current trends and investigative developments in celiac disease

Celiac disease has become extensively studied. What could be the cause? Increasing the accuracy of diagnostic tests for celiac disease has led to more discovered cases. Serological diagnosis of celiac disease has undergone important changes in recent years. Application of serological tests has reflected the diagnostic performance of tissue transglutaminase antibody and endomysial antibody as screening tests for celiac disease but also the progress of new serological tests as the antibodies against synthetic deamidated gliadin peptides. Serological tests are largely responsible for the recognition that celiac disease is not a rare disease. The Consensus in celiac disease from 2008 conducted under the aegis of the European Society of Pediatric Gastroenterology, Hepatology and Nutrition jointly with North American Society of Pediatric Gastroenterology, Hepatology and Nutrition which agreed that "Celiac disease is an immune-mediated enteropathy that can affect any system or organ and that can present itself with a wide range of clinical manifestations of variable severity" was confirmed. But increasing prevalence of this disease has led to the need for new methods of treatment among patients with celiac disease. Studies on quality of life of patients with celiac disease have questioned the gluten-free diet. As such new therapies, like TG2 inhibitors, the copolymer P (HEMA-co-SS) and other new experimental therapies, have emerged in celiac disease. The new therapies in celiac disease are based on new investigations in gluten toxicity screening, like K562(S)-cell agglutination, A1 and G12 monoclonal antibodies and proteomics. In this paper we want to present the investigative developments in celiac disease. We also want to find whether a new treatment in celiac disease is necessary.

[Celiac disease in children from the northwest of Mexico: clinical characteristics of 24 cases]

BACKGROUND

Celiac disease (CD) is an autoimmune enteropathy induced by dietary wheat gluten that can have serious consequences if not diagnosed and treated early. It is important to be familiar with other alterations associated with gluten ingestion due to the multiplicity of clinical presentations.

OBJECTIVES

To describe the most common CD presentation patterns and alterations associated with gluten in children from the northwest region of Mexico, with an incipient knowledge of its prevalence.

PATIENTS AND METHODS

Age, sex, family history, and gastrointestinal and extraintestinal symptoms were recorded in 24 patients within the time frame of 2006 to 2010. Biochemical and hematologic data were collected. Anti-gliadin and anti-transglutaminase antibodies were analyzed in all the cases, and haplotypes (HLA-DQ2/DQ8) and duodenal biopsy were evaluated in some of the cases.

RESULTS

Of the 24 patients (14 girls and 10 boys), 13 presented with typical CD with symptoms of poor gastrointestinal absorption; 7 patients with a mean age of 5 years presented with atypical CD; 2 had disease onset with gastrointestinal and extraintestinal (neurologic) problems; and 2 with other gluten-related disorders. All of the patients had positive serology; 11/15 presented with HLA-DQ2/DQ8 and 4 with at least one allele; damaged mucosa was observed in the 6 biopsies taken. A third of the patients were anemic, 6 presented with an albumin value of<3.5g/dL, and 4 with mineral deficiencies. A total of 83% of the patients improved with a gluten-free diet.

CONCLUSIONS

The presentation patterns were: 1) typical CD, 2) atypical CD, 3) CD with gastrointestinal and extraintestinal (neurologic) symptoms, and 4) gluten-related disorders other than CD.