A duodenal mucosa transcriptome study identified reduced expression of a novel gene CDH18 in celiac disease.

BACKGROUND: Celiac disease (CD) a complex immune disease that affects duodenal mucosa. Identification of tissue specific biomarkers is expected to improve the existing biopsy based CD diagnosis. AIMS: To investigate the differentially expressed genes (DEGs) in duodenal mucosa tissue to identify clinically relevant gene expression pattern in CD. METHODS: Whole RNA extracted from the duodenal biopsies of three CD patients and four non-CD controls were sequenced. Significant DEGs were identified. Prioritized DEGs were validated using qRT-PCR in an independent group (CD=23; Control=26). Enriched pathways were analyzed, protein-protein interaction networks were evaluated. RESULTS: 923 DEGs comprising of 135 up-regulated, and 788 down-regulated genes, with p-value≤0.05; log2FC>2 or <-2 were identified. A novel down-regulated gene CDH18 (p = 0.03; log2FC=-0.74) was identified. Previously known CXCL9 was replicated. CDH18, a trans-membrane protein was found to interact with other CDH proteins, α/ß catenins, and other membrane transporters such as SLC and ABCB. Pathways and protein networks contributing in channel activity (p = 2.15E-12), membrane transporters (p = 2.15E-12), and cellular adhesion (p = 8.05E-6) were identified. CONCLUSIONS: CDH18, a novel DEG identified in the present study is a pivotal gene involved in maintaining epithelial membrane organization and integrity. The functional significance of lower expression of CDH18 in pathogenesis of CD warranted to be investigated. CDH18 expression could be tested for its effectiveness in diagnostic, prognostic and therapeutic purposes.

Evaluation of Nutritional Characteristics Reveals Similar Prevalence of Malnutrition in Patients with Ulcerative Colitis and Crohn's Disease.

BACKGROUND: Inflammatory bowel disease (IBD) is associated with an increased risk of malnutrition and sarcopenia. AIMS: To evaluate the nutritional status of patients with IBD and determine the threshold values of different parameters of nutritional assessment to identify malnutrition. METHODS: This was a single-centre cross-sectional analysis of adult patients with IBD [ulcerative colitis (UC) and Crohn's disease (CD)] who underwent anthropometry [body mass index (BMI), mid upper arm circumference (MUAC) and triceps-fold thickness (TSF)], body composition analysis and assessment for sarcopenia [hand-grip strength and skeletal muscle index (SMI) at L3 vertebral level)]. Age- and gender-matched healthy adults served as controls. Malnutrition was defined according to the European Society of Clinical Nutrition and Metabolism (ESPEN) criteria. RESULTS: A total of 406 patients [336 (82.76%) UC and 70 (17.24%) CD; mean age 40.56 ± 13.67 years; 215 (52.95%) males] with IBD and 100 healthy controls (mean age 38.69 ± 10.90 years; 56 (56%) males) were enrolled. The mean BMI, MUAC, TSF thickness, fat and lean mass, hand-grip strength, and SMI at L3 vertebral level were lower in patients with IBD compared to controls. The prevalence of malnutrition was similar in UC and CD [24.40% (n = 82) and 28.57% (n = 20), respectively (p = 0.46)]. Thresholds for fat mass in females (15.8 kg) and visceral fat index in males (0.26) were both sensitive and specific to detect malnutrition. The cutoff values of MUAC and TSF thickness to identify malnutrition were 23.25 cm and 25.25 cm, and 16.50 mm and 8.50 mm, in females and males, respectively. CONCLUSION: Malnutrition and sarcopenia were common in patients with IBD, with the prevalence being similar in patients with both UC and CD.

An open-label randomised pilot trial on safety of wheat variety C273 in patients with adult celiac disease.

BACKGROUND: The only effective treatment for celiac disease (CeD) is gluten free diet (GFD). However, GFD is restrictive and efforts are being made to explore alternative therapies including safer wheat varieties. Wheat variety C273 has been previously identified to have reduced load of intact T-cell stimulatory epitopes via in silico and in vitro analysis. METHODS: Adult patients diagnosed with CeD and recovered on GFD were included in the study. Patients were randomised into two groups in a 2:1 ratio. Patients in group I had graded introduction of C273 wheat in diet, maintained for 24 weeks; in Group II, wheat was restricted with continuation of GFD. Clinical symptoms, serology [anti-tissue transglutaminase (anti-tTG), anti-endomysial antibody (anti-EMA)], circulating inflammatory biomarkers [intestinal fatty-acid binding protein (I-FABP), plasma citrulline, interferon-γ (IFN-γ)] and histology were evaluated periodically. Final evaluation was performed at week 28. RESULTS: A total of 15 patients were enrolled (Group I: n = 10, Group II: n = 5). All patients except two in Group I remained compliant. None of the remaining eight patients in group I developed symptoms. No significant changes in serology (anti-tTG, anti-EMA) and histology were observed between the two groups at 28 weeks (p > 0.05). Significant changes in plasma citrulline(29.87 ± 8.98 versus 36.58 ± 3.09, p = 0.049) and IFN-γ (44.56 ± 9.74 versus 33.50 ± 3.68; p = 0.031) were observed in Group I. CONCLUSION: Consumption of C273 wheat did not result in development of symptoms or evident changes in serology and histology at 28 weeks. However, variations in circulating inflammatory markers were noted. Larger randomised trials are needed to corroborate these findings. CLINICAL TRIALS REGISTRY-INDIA: CTRI/2018/06/014521.

Variable Immunogenic Potential of Wheat: Prospective for Selection of Innocuous Varieties for Celiac Disease Patients via in vitro Approach.

Celiac Disease (CD) is a multifactorial, autoimmune enteropathy activated by cereal proteins in genetically predisposed individuals carrying HLA DQ2/8 genes. A heterogenous gene combination of the cereal prolamins is documented in different wheat genotypes, which is suggestive of their variable immunogenic potential. In the current study, four wheat varieties (C591, C273, 9D, and K78) identified via in silico analysis were analyzed for immunogenicity by measuring T-cell proliferation rate and levels of inflammatory cytokines (Interferon-γ and Tumor Necrosis Factor-α). Peripheral Blood Mononuclear Cells and biopsy derived T-cell lines isolated from four CD patients in complete remission and two controls were stimulated and cultured in the presence of tissue transglutaminase activated pepsin-trypsin (PT) digest of total gliadin extract from test varieties. The immunogenicity was compared with PBW 621, one of the widely cultivated wheat varieties. Phytohaemagglutinin-p was taken as positive control, along with unstimulated cells as negative control. Rate of cell proliferation (0.318, 0.482; 0.369, 0.337), concentration of IFN- γ (107.4, 99.2; 117.9, 99.7 pg/ml), and TNF- α (453.8, 514.2; 463.8, 514.2 pg/ml) was minimum in cultures supplemented with wheat antigen from C273, when compared with other test varieties and unstimulated cells. Significant difference in toxicity levels among different wheat genotypes to stimulate celiac mucosal T-cells and PBMC's was observed; where C273 manifested least immunogenic response amongst the test varieties analyzed.

Chromofungin Ameliorates the Progression of Colitis by Regulating Alternatively Activated Macrophages.

Ulcerative colitis (UC) is characterized by a functional dysregulation of alternatively activated macrophage (AAM) and intestinal epithelial cells (IECs) homeostasis. Chromogranin-A (CHGA) secreted by neuroendocrine cells is implicated in intestinal inflammation and immune dysregulation. CHGA undergoes proteolytic processing to generate CHGA-derived peptides. Chromofungin (CHR: CHGA47-66) is a short CHGA-derived peptide encoded by CHGA Exon-IV and is involved in innate immune regulation, but the basis is poorly investigated. We investigated the expression of CHR in colonic tissue of patients with active UC and assessed the effects of the CHR in dextran sulfate sodium (DSS) colitis in mice and on macrophages and human colonic epithelial cells. We found that mRNA expression of CHR correlated positively with mRNA levels of AAM markers and gene expression of tight junction (TJ) proteins and negatively with mRNA levels of interleukin (IL)-8, IL-18, and collagen in patients with active UC. Moreover, AAM markers correlated positively with gene expression of TJ proteins and negatively with IL-8, IL-18, and collagen gene expression. Experimentally, intracolonic administration of CHR protected against DSS-induced colitis by priming macrophages into AAM, reducing colonic collagen deposition, and maintaining IECs homeostasis. This effect was associated with a significant increase of AAM markers, reduction of colonic IL-18 release and conservation of gene expression of TJ proteins. In vitro, CHR enhanced AAM polarization and increased the production of anti-inflammatory mediators. CHR-treated AAM conditioned medium increased Caco-2 cell migration, viability, proliferation, and mRNA levels of TJ proteins, and decreased oxidative stress-induced apoptosis and proinflammatory cytokines release. Direct CHR treatments had the same effect. In conclusion, CHR treatment reduces the severity of colitis and the inflammatory process via enhancing AAM functions and maintaining IECs homeostasis. CHR is involved in the pathogenesis of inflammation in experimental colitis. These findings provide insight into the mechanisms of colonic inflammation and could lead to new therapeutic strategies for UC.