First Degree Relatives of Patients with Celiac Disease Harbour an Intestinal Transcriptomic Signature that Might Protect them from Enterocyte Damage

Global Prevalence and Clinical Manifestations of Celiac Disease Among First-Degree Relatives: A Systematic Review and Meta-Analysis

INTRODUCTION

First-degree relatives (FDRs) of patients with celiac disease (CeD) are at high risk for developing CeD. We conducted a systematic review and meta-analysis to estimate CeD prevalence and clinical manifestations by analyzing studies that used the anti-tissue transglutaminase antibody test for screening.

METHODS

In this systematic review with meta-analysis, studies published in PubMed, Web of Science, Embase, and Scopus were searched up to January 11, 2024, using keywords related to CeD and FDRs. Random-effects models were used, with heterogeneity assessed using the Cochran Q test and the I2 statistic performed in STATA 18.

RESULTS

Of 8,764 studies screened, 34 studies involving 10,016 FDRs of patients with CeD were included. The pooled estimates for seroprevalence and the biopsy-confirmed CeD prevalence in FDRs were 11% (95% CI: 9%-13%) and 7% (95% CI: 6%-9%), respectively. Daughters and sisters had the highest prevalence rates at 23% and 14%, compared with sons and brothers at 6% and 9%, respectively. Regional analysis revealed the highest seroprevalence estimates in Hungary (24%) and Cuba (19%), while the highest prevalence of biopsy-confirmed CeD was reported in Serbia (16%) and the United States (15%). Abdominal pain (42%), bloating (39%), and flatulence (38%) were the most common gastrointestinal symptoms, while 34% of FDRs with CeD were asymptomatic. In addition, pallor was the most frequent nongastrointestinal symptom (54%).

DISCUSSION

Approximately 1 in 14 FDRs of patients with CeD is estimated to have CeD, with 1 in 4 daughters, 1 in 7 sisters, 1 in 11 brothers, 1 in 16 sons, and 1 in 20 fathers and mothers could be affected. Routine screening for FDRs could support early detection and management of CeD.

A Systems Biology Approach to the Pathogenesis of Celiac Disease: Identification of Potential Protective and Promoting Mechanisms

Background

Celiac disease (CeD) is an autoimmune enteropathy triggered by dietary gluten. Almost 90% of CeD patients have HLA-DQ2 or -DQ8 haplotypes. As a high proportion of first-degree relatives (FDRs) of CeD patients have the same haplotype, it is assumed that they are at a higher risk of disease development than the general population. Nevertheless, the prevalence of CeD among FDRs is considerably low (7.5%).

Materials and Methods

In order to figure out this discrepancy, a microarray dataset of intestinal mucosal biopsies of CeD patients, FDRs, and control groups was reanalyzed, and a protein-protein interaction network was constructed.

Results

Principal component analysis showed that CeD and FDR groups are far away in terms of gene expression. Comparing differentially expressed genes of both networks demonstrated inverse expression of some genes mainly related to cell cycle mechanisms. Moreover, analysis of the modular structures of up- and downregulated gene networks determined activation of protein degradation mechanisms and inhibition of ribosome-related protein synthesis in celiac patients with an upside-down pattern in FDRs.

Conclusions

The top-down systems biology approach determined some regulatory pathways with inverse function in CeD and FDR groups. These genes and molecular mechanisms could be a matter of investigation as potential druggable targets or prognostic markers in CeD.

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/β 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.

Transcriptome profile and immune infiltrated landscape revealed a novel role of γδT cells in mediating pyroptosis in celiac disease

BACKGROUND

Celiac disease (CeD) is a primary malabsorption syndrome with no specific therapy, which greatly affects the quality of life. Since the pathogenesis of CeD remains riddled, based on multiple transcriptome profiles, this study aimed to establish an immune interaction network and elucidated new mechanisms involved in the pathogenesis of CeD, providing potentially new evidence for the diagnosis and treatment of CeD.

METHODS

Three microarray and three RNA sequencing datasets of human duodenal tissue with or without CeD were included in Gene Expression Omnibus and respectively merged into derivation and validation cohorts. Differential expression gene and functional enrichment analysis were developed, then pyroptosis enrichment score (PES) model was established to quantify pyroptosis levels. Immune infiltration and co-expression network were constructed based on Xcell database. Protein-protein interaction and weighted gene co-expression network analysis were determined to identify pyroptosis relative hub genes, whose predictive efficiency were tested using a least absolute shrinkage and selection operator (LASSO) regression model. CeD animal and in vitro cell line models were established to verify the occurrence of pyroptosis and molecules expression employing immunofluorescence, western blotting, cell counting kit-8 assay and enzyme-linked immunosorbent assay. Analysis of single-cell RNAseq (scRNAseq) was performed using "Seurat" R package.

RESULTS

Differentially expressed genes (DEGs) (137) were identified in derivation cohort whose function was mainly enriched in interferon response and suppression of metabolism. Since an enrichment of pyroptosis pathway in CeD was unexpectedly discovered, a PES model with high efficiency was constructed and verified with two external databases, which confirmed that pyroptosis was significantly upregulated in CeD epithelia. γδT cells exhibited high expression of IFN-γ were the most relevant cells associated with pyroptosis and occupied a greater weight in the LASSO predictive model of CeD. An accumulation of GSDMD expressed in epithelia was identified using scRNAseq, while animal model and in vitro experiments confirmed that epithelium cells were induced to become "pre-pyroptotic" status via IFN-γ/IRF1/GSDMD axis. Furthermore, gluten intake triggered pyroptosis via caspase-1/GSDMD/IL-1β pathway.

CONCLUSION

Our study demonstrated that pyroptosis was involved in the pathogenesis of CeD, and elucidated the novel role of γδT cells in mediating epithelial cell pyroptosis.

Analysis of Circulating Food Antigen-Specific T-Cells in Celiac Disease and Inflammatory Bowel Disease

To demonstrate and analyze the specific T-cell response following barrier disruption and antigen translocation, circulating food antigen-specific effector T-cells isolated from peripheral blood were analyzed in patients suffering from celiac disease (CeD) as well as inflammatory bowel disease (IBD). We applied the antigen-reactive T-cell enrichment (ARTE) technique allowing for phenotypical and functional flow cytometric analyses of rare nutritional antigen-specific T-cells, including the celiac disease-causing gliadin (gluten). For CeD, patient groups, including treatment-refractory cases, differ significantly from healthy controls. Even symptom-free patients on a gluten-free diet were distinguishable from healthy controls, without being previously challenged with gluten. Moreover, frequency and phenotype of nutritional antigen-specific T-cells of IBD patients directly correlated to the presence of small intestinal inflammation. Specifically, the frequency of antigen specific T-cells as well as pro-inflammatory cytokines was increased in patients with active CeD or Crohn's disease, respectively. These results suggest active small intestinal inflammation as key for the development of a peripheral food antigen-specific T-cell response in Crohn's disease and celiac disease.

The pseudogenes of eukaryotic translation elongation factors (EEFs): Role in cancer and other human diseases

The eukaryotic translation elongation factors (EEFs), i.e. EEF1A1, EEF1A2, EEF1B2, EEF1D, EEF1G, EEF1E1 and EEF2, are coding-genes that play a central role in the elongation step of translation but are often altered in cancer. Less investigated are their pseudogenes. Recently, it was demonstrated that pseudogenes have a key regulatory role in the cell, especially via non-coding RNAs, and that the aberrant expression of ncRNAs has an important role in cancer development and progression. The present review paper, for the first time, collects all that published about the EEFs pseudogenes to create a base for future investigations. For most of them, the studies are in their infancy, while for others the studies suggest their involvement in normal cell physiology but also in various human diseases. However, more investigations are needed to understand their functions in both normal and cancer cells and to define which can be useful biomarkers or therapeutic targets.

Defining the Celiac Disease Transcriptome using Clinical Pathology Specimens Reveals Biologic Pathways and Supports Diagnosis

Celiac disease is provoked by gluten exposure, but the complete pathogenic process in the duodenum and the loss of tolerance to gluten is not well understood. We aimed to define the core celiac transcriptomic signature and pathologic pathways in pre-treatment formalin-fixed paraffin-embedded (FFPE) duodenum biopsies used for clinical diagnosis. We use mRNAseq to define pre-treatment diagnostic duodenum gene expression in 54 pediatric celiac patients and non-celiac controls, and we validate our key findings in two independent cohorts of 67 adults and pediatric participants that used fresh frozen biopsies. We further define similar and divergent genes and pathways in 177 small bowel Crohn disease patients and controls. We observe a marked suppression of mature epithelial metabolic functions in celiac patients, overlapping substantially with the Crohn disease signature. A marked adaptive immune response was noted for the up-regulated signature including interferon response, alpha-beta, and gamma-delta T-cells that overlapped to some extent with the Crohn disease signature. However, we also identified a celiac disease specific signature linked to increased cell proliferation, nuclear division, and cell cycle activity that was localized primarily to the epithelia as noted by CCNB1 and Ki67 staining. Lastly, we demonstrate the utility of the transcriptomic date to correctly classify disease or healthy states in the discovery and validation cohorts. Our data supplement recently published datasets providing insights into celiac pathogenesis using clinical pathology FFPE samples, and can stimulate new approaches to address this highly prevalent condition.