Intestinal stem cells and celiac disease

Immunohistochemical evaluation of LGR5, CD71, CD138 and CXCR3 markers in the small bowel mucosa of participants with celiac disease and persons with normal bowel mucosa

Celiac disease (CD) is a chronic autoimmune disease of the small bowel mucosa that develops because of the altered immune response to gluten, which leads to intestinal epithelium damage and villous atrophy. However, studies on regeneration of the damaged small bowel mucosa and density of intestinal stem cells (ISC) in CD persons are still scarce. We aimed to evaluate the number of small bowel mucosa cells positive for LGR5, CD138/Syndecan-1, CD71 and CXCR3 in CD and in controls with normal bowel mucosa; to find relationship between these markers and degree of small intestinal atrophy and to compare these results with our previous data about the number of CD103 + , IDO + DCs, FOXP3 + Tregs, enterovirus (EV) density and serum zonulin level. The paraffin sections of the small bowel biopsies were obtained from 26 children with CD (median age 6.5 years), and from 20 controls with normal intestinal mucosa (median age 14.2 years) and from the tissue bank of the Department of Pathology of Tartu University Hospital (from 18 participants with CD including 14 children (median age 13.2 years) and from 11subjects with normal small bowel mucosa, including one child aged 4.8 years. The number of LGR5 + , CD71 + , CD138 + , and CXCR3 + cells was evaluated using immunohistochemistry. The median number of CD138 + and CXCR3 + cells was significantly higher in the small bowel mucosa in CD compared with normal mucosa (p = 0.0002 for CD138 and p = 0.006 for CXCR3). The median number of CD71 + cells was significantly higher in normal small bowel mucosa (p = 0.005). The number of LGR5 + cells did not differ between persons with CD and those with normal small bowel mucosa (p = 0.7). A markedly increased number of CD138 + and CXCR3 + cells in the small bowel mucosa of participants with CD confirms their role in the pathogenesis of this disease. There was no expected marked difference in the density of any of the studied markers between lower or higher grade of small bowel atrophy and level of tTG-IgA in CD.

Intestinal stem cell niche: An upcoming area of immense importance in gastrointestinal disorders

The intestinal stem cell (ISC) niche is vital for maintaining the integrity and function of the intestinal epithelium. ISC populations, characterized by their high proliferation and multipotency, reside within a specialized microenvironment at the base of crypts. Crypt base columnar (CBC) cells at the deepest part of crypts serve as replicating ISCs, while position 4 label-retaining cells (LRCs) located higher up in the crypts are also important for ISC maintenance during experiments. The interplay between CBCs, position 4 LRCs, transient amplifying (TA) cells and other niche components, including the pericrypt stromal cells, ensures a continuous supply of differentiated epithelial cells. Recent advancements in ISC biomarker studies have provided valuable insights into their molecular signatures, regulatory pathways and roles in the pathogenesis of intestinal disorders. Understanding the ISC niche has significant therapeutic implications, as manipulating ISC behaviors and regenerating damaged or diseased intestinal tissue show promise for novel therapeutic approaches. ISC organoids have also provided a platform for studying intestinal diseases and testing personalized therapies. This comprehensive review covers the anatomical composition, physiological regulation, ISC biomarker studies, contribution to intestinal disorder pathogenesis and potential therapeutic implications of the ISC niche.

Potential therapeutic options for celiac Disease: An update on Current evidence from Gluten-Free diet to cell therapy

Celiac disease (CD) is a chronic autoimmune enteropathy and multifactorial disease caused by inappropriate immune responses to gluten in the small intestine. Weight loss, anemia, osteoporosis, arthritis, and hepatitis are among the extraintestinal manifestations of active CD. Currently, a strict lifelong gluten-free diet (GFD) is the only safe, effective, and available treatment. Despite the social burden, high expenses, and challenges of following a GFD, 2 to 5 percent of patients do not demonstrate clinical or pathophysiological improvement. Therefore, we need novel and alternative therapeutic approaches for patients. Innovative approaches encompass a broad spectrum of strategies, including enzymatic degradation of gluten, inhibition of intestinal permeability, modulation of the immune response, inhibition of the transglutaminase 2 (TG2) enzyme, blocking antigen presentation by HLA-DQ2/8, and induction of tolerance. Hence, this review is focused on comprehensive therapeutic strategies ranging from dietary approaches to novel methods such as antigen-based immunotherapy, cell and gene therapy, and the usage of nanoparticles for CD treatment.

Correlation between intestinal stem cell niche changes and small bowel crypt failure in patients with treatment-naïve celiac disease

OBJECTIVES

We hypothesized that crypt failure in the small bowel results in villous flattening in patients with celiac disease (CeD). We investigated whether alterations in the stem cell niche (ISC) are responsible for this phenomenon.

MATERIALS AND METHODS

We included 92 duodenal (D2/3) biopsies from treatment-naive patients of CeD and 37 controls. All underwent screening for serum anti-tissue transglutaminase and endoscopic upper small bowel biopsy. Immunohistochemical markers were used to investigate ISC niche alterations, including LGR5 for crypt basal cells (CBC), Bmi1 for position 4+ cells, β-Defensin for Paneth cells, R-spondin1 as WNT activator, transcription factor-4 as WNT transcription factor, BMP receptor1A as WNT inhibitor, fibronectin-1 as periepithelial stromal cell marker, H2AX as apoptosis marker, and Ki67 as proliferation marker. We also analyzed IgA anti-tTG2 antibody deposits by using dual-color immunofluorescence staining.

RESULTS

We found that in biopsies from patients with treatment-naive CeD with modified Marsh grade 3a-3c changes, the epithelial H2AX apoptotic index was upregulated than in controls. LGR5+ crypt basal cells were upregulated in all modified Marsh grades compared to controls. However, the Ki67 proliferation index, expressions of WNT-activator RSPO1, and position-4 cell marker Bmi1 did not significantly alter in patients' biopsies as compared to controls ( P = 0.001). We also observed depletion of pericrypt stromal fibronectin-1 in patients with CeD compared to controls. In addition, we identified IgA anti-TG2 antibody deposits in pericrypt stroma.

CONCLUSIONS

Our data suggests that ISC niche failure is a plausible hypothesis for villous flattening in patients with CeD, resulting from pericrypt IgA anti-TG2 antibody complex-mediated stromal depletion.

Expression of Selected Genes and Circulating microRNAs in Patients with Celiac Disease

Background and Objectives: Celiac disease (CD) is an immune-mediated enteropathy with characteristic intestinal alterations. CD occurs as a chronic inflammation secondary to gluten sensitivity in genetically susceptible individuals. Until now, the exact cause of the disease has not been established, which is why new studies have appeared that address the involvement of various genes and microRNAs (miRNAs) in the pathogenesis. The aim of the study is to describe the expression of selected genes (Wnt family member 3, WNT3; Wnt family member 11, WNT11; tumor necrosis factor alpha, TNFα; mitogen-activated protein kinase 1, MAPK1; AKT serine/threonine kinase 3, AKT3; phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha, PIK3CA; and cyclin D1, CCND1) and miRNAs (miR-192-5p, miR-194-5p, miR-449a and miR-638) in adult patients with CD. Materials and Methods: In total, 15 patients with CD at diagnosis (newly diagnosed), 33 patients on a gluten-free diet (GFD) for at least 1 year and 10 controls (control) were prospectively included. Blood samples were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). Results: The results show that TNFα, MAPK1 and CCND1 were significantly overexpressed (p = 0.0249, p = 0.0019 and p = 0.0275, respectively) when comparing the newly diagnosed group to the controls. The other genes studied in CD patients were mostly with high values compared to controls, without reaching statistical significance. Among the miRNAs, the closest to a statistically significant value was miR-194-5p when the newly diagnosed group versus control (p = 0.0510) and GFD group versus control (p = 0.0671) were compared. The DIANA and miRNet databases identified significant functional activity for miR-449a and miR-192-5p and an interconnection of miR-194-5p and miR-449a with CCND1. Conclusions: In conclusion, genes and circulating miRNAs require further studies as they could represent important biomarkers in clinical practice.

Green tea derivative (-)-epigallocatechin-3-gallate (EGCG) confers protection against ionizing radiation-induced intestinal epithelial cell death both in vitro and in vivo

Radiation-induced intestinal injury (RIII) occurs during instances of intentional or accidental radiation exposure. However, there are few effective treatments available for the prevention or mitigation of RIII currently. (-)-Epigallocatechin-3-gallate (EGCG), a major polyphenol in green tea, possesses potent antioxidant activity and has been shown to be effective in ameliorating many oxidative stress-related diseases. The therapeutic effects and mechanism of EGCG on RIII have not yet been determined. In the present study, we investigated whether EGCG confers radioprotection against RIII. Our data demonstrated that administration of EGCG not only prolonged the survival time of lethally irradiated mice, but also reduced radiation-induced intestinal mucosal injury. Treatment with EGCG significantly increased the number of Lgr5⁺ intestinal stem cells (ISCs) and their progeny Ki67⁺ cells, and reduced radiation-induced DNA damage and apoptosis. Besides, EGCG displayed the same radioprotective effects in human intestinal epithelial HIEC cells as in mice, characterized by a decrease in the number of γH2AX foci and ferroptosis. Moreover, EGCG decreased the level of reactive oxygen species (ROS) and activated the transcription factor Nrf2 and its downstream targets comprising antioxidant proteins Slc7A11, HO-1 and GPX4. Treatment with the Nrf2 inhibitor ML385 abolished the protective effects of EGCG, indicating that Nrf2 activation is essential for EGCG activity. Taken together, our findings demonstrated that EGCG protects against RIII by scavenging ROS and inhibiting apoptosis and ferroptosis through the Nrf2 signal pathway, which could be a promising medical countermeasure for the alleviation of RIII.

Intestinal ex vivo organoid culture reveals altered programmed crypt stem cells in patients with celiac disease

The ex vivo generation of gastrointestinal organoids from crypt stem cells opens up the possibility of new research approaches investigating gastrointestinal diseases. We used this technology to study differences between healthy controls and patients with celiac disease (CD). We noticed distinct dissimilarities in the phenotypes of organoids between our study groups and found considerable variations in their gene expression. Extracellular matrix genes involved in epithelial-mesenchymal transition are expressed most differently. In addition, we demonstrated epigenetic modifications that might be responsible for the different organoid gene expression thus accounting for a deranged crypt/villus axis development in CD. The organoids have proven valuable to demonstrate fundamental differences in duodenal derived organoids between healthy controls and patients with CD and thus are a suitable tool to gain new insights in pathogenesis of CD.

Intestinal organoids for modelling intestinal development and disease

Gastrointestinal diseases are becoming increasingly prevalent in developed countries. Immortalized cells and animal models have delivered important but limited insight into the mechanisms that initiate and propagate these diseases. Human-specific models of intestinal development and disease are desperately needed that can recapitulate structure and function of the gut in vitro Advances in pluripotent stem cells and primary tissue culture techniques have made it possible to culture intestinal epithelial cells in three dimensions that self-assemble to form 'intestinal organoids'. These organoids allow for new, human-specific models that can be used to gain insight into gastrointestinal disease and potentially deliver new therapies to treat them. Here we review current in vitro models of intestinal development and disease, considering where improvements could be made and potential future applications in the fields of developmental modelling, drug/toxicity testing and therapeutic uses.This article is part of the theme issue 'Designer human tissue: coming to a lab near you'.

Bifidobacterium infantis NLS Super Strain Reduces the Expression of α-Defensin-5, a Marker of Innate Immunity, in the Mucosa of Active Celiac Disease Patients

BACKGROUND

We have previously shown a reduction of gastrointestinal symptoms after the oral administration of Bifidobacterium infantis Natren Life Start super strain (NLS-SS) in untreated celiac disease (CD) patients. The symptomatic improvement was not associated with changes in intestinal permeability or serum levels of cytokines, chemokines, or growth factors. Therefore, we hypothesized that the beneficial symptomatic effect observed previously in patients with CD treated with B. infantis may be related to the modulation of innate immunity.

GOALS

To investigate the potential mechanisms of a probiotic B. infantis Natren Life Start super strain on the mucosal expression of innate immune markers in adult patients with active untreated CD compared with those treated with B. infantis×6 weeks and after 1 year of gluten-free diet (GFD).

METHODS

Numbers of macrophages and Paneth cells and α-defensin-5 expression were assessed by immunohistochemistry in duodenal biopsies.

RESULTS

We showed that GFD decreases duodenal macrophage counts in CD patients more effectively than B. infantis. In contrast, B. infantis decreases Paneth cell counts and expression of α-defensin-5 in CD (P<0.001).

CONCLUSIONS

The results identify differential innate immune effects of treatment with B. infantis compared with 1 year of GFD. Further studies are needed to investigate synergistic effects of GFD and B. infantis supplementation in CD.

Association of hepatocyte-derived growth factor receptor/caudal type homeobox 2 co-expression with mucosal regeneration in active ulcerative colitis

AIM: To characterize the regeneration-associated stem cell-related phenotype of hepatocyte-derived growth factor receptor (HGFR)-expressing cells in active ulcerative colitis (UC).

METHODS: On the whole 38 peripheral blood samples and 38 colonic biopsy samples from 18 patients with histologically proven active UC and 20 healthy control subjects were collected. After preparing tissue microarrays and blood smears HGFR, caudal type homeobox 2 (CDX2), prominin-1 (CD133) and Musashi-1 conventional and double fluorescent immunolabelings were performed. Immunostained samples were digitalized using high-resolution Mirax Desk instrument, and analyzed with the Mirax TMA Module software. For semiquantitative counting of immunopositive lamina propria (LP) cells 5 fields of view were counted at magnification × 200 in each sample core, then mean ± SD were determined. In case of peripheral blood smears, 30 fields of view with 100 μm diameter were evaluated in every sample and the number of immunopositive cells (mean ± SD) was determined. Using 337 nm UVA Laser MicroDissection system at least 5000 subepithelial cells from the lamina propria were collected. Gene expression analysis of HGFR, CDX2, CD133, leucine-rich repeat-containing G-protein coupled receptor 5 (Lgr5), Musashi-1 and cytokeratin 20 (CK20) were performed in both laser-microdisscted samples and blood samples by using real time reverse transcription polymerase chain reaction (RT-PCR).

RESULTS: By performing conventional and double fluorescent immunolabelings confirmed by RT-PCR, higher number of HGFR (blood: 6.7 ± 1.22 vs 38.5 ± 3.18; LP: 2.25 ± 0.85 vs 9.22 ± 0.65; P < 0.05), CDX2 (blood: 0 vs 0.94 ± 0.64; LP: 0.75 ± 0.55 vs 2.11 ± 0.75; P < 0.05), CD133 (blood: 1.1 ± 0.72 vs 8.3 ± 1.08; LP: 11.1 ± 0.85 vs 26.28 ± 1.71; P < 0.05) and Musashi-1 (blood and LP: 0 vs scattered) positive cells were detected in blood and lamina propria of UC samples as compared to controls. HGFR/CDX2 (blood: 0 vs 1 ± 0.59; LP: 0.8 ± 0.69 vs 2.06 ± 0.72, P < 0.05) and Musashi-1/CDX2 (blood and LP: 0 vs scattered) co-expressions were found in blood and lamina propria of UC samples. HGFR/CD133 and CD133/CDX2 co-expressions appeared only in UC lamina propria samples. CDX2, Lgr5 and Musashi-1 expressions in UC blood samples were not accompanied by CK20 mRNA expression.

CONCLUSION: In active UC, a portion of circulating HGFR-expressing cells are committed to the epithelial lineage, and may participate in mucosal regeneration by undergoing mesenchymal-to-epithelial transition.

Circulating hematopoietic stem cells and putative intestinal stem cells in coeliac disease

Background

The intestinal stem cells (ISC) modulation and the role of circulating hematopoietic stem cells (HSC) in coeliac disease (CD) are poorly understood. Our aim was to investigate the longitudinal modifications in peripheral blood HSC traffic and putative ISC density induced by gluten-free diet (GFD) in CD.

Methods

Thirty-one CD patients and 7 controls were enrolled. Circulating CD133⁺ and CD34⁺ HSC were measured by flow cytometry, at enrolment and after 7 days and 1, 3, 6, 12, and 24 months of GFD. Endoscopy was performed at diagnosis and repeated at 6, 12, and 24 months following GFD. We used the Marsh-Oberhuber score to evaluate the histological severity of duodenal damage; immunohistochemistry was employed to measure the intraepithelial lymphoid infiltrate (IEL, CD3⁺ lymphoid cells) and the putative ISC compartment (CD133⁺ and Lgr5⁺ epithelial cells).

Results

At enrolment, circulating HSCs were significantly increased in CD patients and they further augmented during the first week of GFD, but progressively decreased afterwards. CD patients presented with villous atrophy, abundant IEL and rare ISC residing at the crypt base. Upon GFD, IEL progressively decreased, while ISC density increased, peaking at 12 months. After 24 months of GFD, all patients were asymptomatic and their duodenal mucosa was macroscopically and histologically normal.

Conclusions

In active CD patients, the ISC niche is depleted and there is an increased traffic of circulating HSC versus non-coeliac subjects. GFD induces a precocious mobilization of circulating HSC, which is followed by the expansion of the local ISC compartment, leading to mucosal healing and clinical remission.