CDX2 upregulates SLC26A3 gene expression in intestinal epithelial cells

SLC26A3 [downregulated in adenoma (DRA)] plays a key role in mammalian intestinal NaCl absorption, in that it mediates apical membrane Cl−/[Formula: see text] exchange. DRA function and expression are significantly decreased in diarrhea associated with inflammatory bowel disease. DRA is also considered to be a marker of cellular differentiation and is predominantly expressed in differentiated epithelial cells. Caudal-type homeobox protein-2 (CDX2) is known to regulate genes involved in intestinal epithelial differentiation and proliferation. Reduced expression of both DRA and CDX2 in intestinal inflammation prompted us to study whether the DRA gene is directly regulated by CDX2. Our initial studies utilizing CDX2 knockout (CDX2fV/fV;Cre+) mice showed a marked reduction in DRA mRNA and protein levels in proximal and distal colon. In silico analysis of the DRA promoter showed two consensus sites for CDX2 binding. Therefore, we utilized Caco-2 cells as an in vitro model to examine if DRA is a direct target of CDX2 regulation. siRNA-mediated silencing of CDX2 in Caco-2 cells resulted in a marked (~50%) decrease in DRA mRNA and protein levels, whereas ectopic overexpression of CDX2 upregulated DRA expression and also stimulated DRA promoter activity, suggesting transcriptional regulation. Electrophoretic mobility shift and chromatin immunoprecipitation assays demonstrated direct binding of CDX2 to one of the two putative CDX2 binding sites in the DRA promoter (+645/+663). In summary, our studies, for the first time, demonstrate transcriptional regulation of DRA expression by CDX2, implying that reduced expression of DRA in inflammatory bowel disease-associated diarrhea may, in part, be due to downregulation of CDX2 in the inflamed mucosa. NEW & NOTEWORTHY SLC26A3 [downregulated in adenoma (DRA)] mediates intestinal luminal NaCl absorption and is downregulated in inflammatory bowel disease-associated diarrhea. Since both DRA and caudal-type homeobox protein-2 (CDX2) are reduced in intestinal inflammation and the DRA promoter harbors CDX2 binding sites, we examined whether the DRA gene is regulated by CDX2. Our studies, for the first time, demonstrate transcriptional regulation of DRA expression by CDX2 via direct binding to the DRA promoter, suggesting that reduced expression of DRA in inflammatory bowel disease-associated diarrhea could, in part, be attributed to downregulation of CDX2.

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Thymus leukemia antigen controls intraepithelial lymphocyte function and inflammatory bowel disease

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.0808242105 ◽

2008 ◽

Vol 105 (46) ◽

pp. 17931-17936 ◽

Cited By ~ 38

Author(s):

Danyvid Olivares-Villagómez ◽

Yanice V. Mendez-Fernandez ◽

Vrajesh V. Parekh ◽

Saif Lalani ◽

Tiffaney L. Vincent ◽

...

Keyword(s):

Inflammatory Bowel Disease ◽

Bowel Disease ◽

Intestinal Inflammation ◽

Genetic Model ◽

Critical Role ◽

Intraepithelial Lymphocytes ◽

Lymphocyte Function ◽

Intestinal Epithelial ◽

Inflammatory Bowel

Intestinal intraepithelial lymphocytes (IEL) bear a partially activated phenotype that permits them to rapidly respond to antigenic insults. However, this phenotype also implies that IEL must be highly controlled to prevent misdirected immune reactions. It has been suggested that IEL are regulated through the interaction of the CD8αα homodimer with the thymus leukemia (TL) antigen expressed by intestinal epithelial cells. We have generated and characterized mice genetically-deficient in TL expression. Our findings show that TL expression has a critical role in maintaining IEL effector functions. Also, TL deficiency accelerated colitis in a genetic model of inflammatory bowel disease. These findings reveal an important regulatory role of TL in controlling IEL function and intestinal inflammation.

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Deficiency in the anti-apoptotic protein DJ-1 promotes intestinal epithelial cell apoptosis and aggravates inflammatory bowel disease via p53

Journal of Biological Chemistry ◽

10.1074/jbc.ra119.010143 ◽

2020 ◽

Vol 295 (13) ◽

pp. 4237-4251 ◽

Cited By ~ 1

Author(s):

Jie Zhang ◽

Min Xu ◽

Weihua Zhou ◽

Dejian Li ◽

Hong Zhang ◽

...

Keyword(s):

Inflammatory Bowel Disease ◽

Epithelial Cell ◽

Bowel Disease ◽

Intestinal Epithelial Cell ◽

Intestinal Inflammation ◽

Intestinal Epithelial ◽

P53 Expression ◽

Inflammatory Bowel

Parkinson disease autosomal recessive, early onset 7 (PARK7 or DJ-1) is involved in multiple physiological processes and exerts anti-apoptotic effects on multiple cell types. Increased intestinal epithelial cell (IEC) apoptosis and excessive activation of the p53 signaling pathway is a hallmark of inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD). However, whether DJ-1 plays a role in colitis is unclear. To determine whether DJ-1 deficiency is involved in the p53 activation that results in IEC apoptosis in colitis, here we performed immunostaining, real-time PCR, and immunoblotting analyses to assess DJ-1 expression in human UC and CD samples. In the inflamed intestines of individuals with IBD, DJ-1 expression was decreased and negatively correlated with p53 expression. DJ-1 deficiency significantly aggravated colitis, evidenced by increased intestinal inflammation and exacerbated IEC apoptosis. Moreover, DJ-1 directly interacted with p53, and reduced DJ-1 levels increased p53 levels both in vivo and in vitro and were associated with decreased p53 degradation via the lysosomal pathway. We also induced experimental colitis with dextran sulfate sodium in mice and found that compared with DJ-1−/− mice, DJ-1−/−p53−/− mice have reduced apoptosis and inflammation and increased epithelial barrier integrity. Furthermore, pharmacological inhibition of p53 relieved inflammation in the DJ-1−/− mice. In conclusion, reduced DJ-1 expression promotes inflammation and IEC apoptosis via p53 in colitis, suggesting that the modulation of DJ-1 expression may be a potential therapeutic strategy for managing colitis.

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Temporal induction of intestinal epithelial hypoxia-inducible factor-2α is sufficient to drive colitis

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00081.2019 ◽

2019 ◽

Vol 317 (2) ◽

pp. G98-G107 ◽

Cited By ~ 2

Author(s):

Sumeet Solanki ◽

Samantha N. Devenport ◽

Sadeesh K. Ramakrishnan ◽

Yatrik M. Shah

Keyword(s):

Inflammatory Bowel Disease ◽

Epithelial Cells ◽

Inflammatory Response ◽

Bowel Disease ◽

Intestinal Inflammation ◽

Intestinal Epithelial Cells ◽

Hypoxia Inducible Factor ◽

Intestinal Epithelial ◽

Inflammatory Bowel

Hypoxia is a notable feature of inflammatory bowel disease and chronic induction of hypoxia-inducible factor (HIF)-1α and HIF-2α (endothelial PAS domain protein 1, EPAS1) play important, but opposing, roles in its pathogenesis. While activation of HIF-1α decreases intestinal inflammation and is beneficial in colitis, activation of HIF-2α exacerbates colitis and increases colon carcinogenesis in animal models, primarily due to the role of epithelial HIF-2α in mounting a potent inflammatory response. Previous work from our laboratory showed that mice overexpressing intestinal epithelial HIF-2α led to massive intestinal inflammation and decreased survival. As oxygen homeostasis and HIFs are critical in embryonic development, it is not clear whether the observed intestinal inflammatory response was secondary to developmental defects. To address this question, the present study used a mouse model to temporally modulate expression of intestinal epithelial HIF-2α to assess its role in mediating inflammatory response. Remarkably, activation of HIF-2α in intestinal epithelial cells in adult mice increased expression of proinflammatory mediators; however, no decrease in survival was observed. Furthermore, in an acute model of colitis, activation of HIF-2α was sufficient to exacerbate colitis. These data confirm our previous finding that epithelial HIF-2α mediates inflammatory response and demonstrates that activation of HIF-2α is sufficient to exacerbate colitis.NEW & NOTEWORTHY Inflammatory bowel disease (IBD) is a chronic relapsing inflammatory disease of the intestinal tract. Hypoxia and activation of its downstream transcription factors hypoxia-inducible factor (HIF)-1α and HIF-2α are notable features of IBD. HIF-1α has well-characterized protective roles in IBD; however, the role of HIF-2α has been less studied. Using novel HIF-2α mouse models, we show that activation of HIF-2α in intestinal epithelial cells is sufficient to exacerbate colitis.

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Local Stabilization of Hypoxia-Inducible Factor-1α Controls Intestinal Inflammation via Enhanced Gut Barrier Function and Immune Regulation

Frontiers in Immunology ◽

10.3389/fimmu.2020.609689 ◽

2021 ◽

Vol 11 ◽

Author(s):

Young-In Kim ◽

Eun-Je Yi ◽

Young-Dae Kim ◽

A Reum Lee ◽

Jiwoung Chung ◽

...

Keyword(s):

Inflammatory Bowel Disease ◽

Bowel Disease ◽

Barrier Function ◽

Intestinal Inflammation ◽

Hypoxia Inducible Factor ◽

Intestinal Epithelial ◽

Intestinal Trefoil Factor ◽

Gut Barrier Function ◽

Tissue Healing ◽

Inflammatory Bowel

Intestinal epithelial cells are adapted in mucosal hypoxia and hypoxia-inducible factors in these cells can fortify barrier integrity to support mucosal tissue healing. Here we investigated whether hypoxia-related pathways could be proposed as potential therapeutic targets for inflammatory bowel disease. We developed a novel hypoxia-inducible factor (HIF) prolyl hydroxylase inhibitor, CG-598 which stabilized HIF-1α in the gut tissue. Treatment of CG-598 did not affect extra-intestinal organs or cause any significant adverse effects such as erythropoiesis. In the experimental murine colitis model, CG-598 ameliorated intestinal inflammation with reduction of inflammatory lesions and pro-inflammatory cytokines. CG-598 treatment fortified barrier function by increasing the expression of intestinal trefoil factor, CD73, E-cadherin and mucin. Also, IL-10 and IL-22 were induced from lamina propria CD4+ T-cells. The effectiveness of CG-598 was comparable to other immunosuppressive therapeutics such as TNF-blockers or JAK inhibitors. These results suggest that CG-598 could be a promising therapeutic candidate to treat inflammatory bowel disease.

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Interleukin 34: a new modulator of human and experimental inflammatory bowel disease

Clinical Science ◽

10.1042/cs20150176 ◽

2015 ◽

Vol 129 (3) ◽

pp. 281-290 ◽

Cited By ~ 45

Author(s):

Stephanie Zwicker ◽

Gisele L. Martinez ◽

Madeleen Bosma ◽

Marco Gerling ◽

Reuben Clark ◽

...

Keyword(s):

Inflammatory Bowel Disease ◽

Epithelial Cells ◽

Bowel Disease ◽

Intestinal Inflammation ◽

Intestinal Epithelial Cells ◽

Intestinal Epithelial ◽

Macrophage Differentiation ◽

Differentiation Factor ◽

Experimental Inflammatory Bowel Disease ◽

Inflammatory Bowel

The macrophage differentiation factor interleukin-34, produced by intestinal epithelial cells, is up-regulated in patients with inflammatory bowel disease, and may be a novel modulator of intestinal inflammation.

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RNF20 and RNF40 regulate vitamin D receptor-dependent signaling in inflammatory bowel disease

Cell Death and Differentiation ◽

10.1038/s41418-021-00808-w ◽

2021 ◽

Author(s):

Robyn Laura Kosinsky ◽

Maria Zerche ◽

Ana Patricia Kutschat ◽

Asha Nair ◽

Zhenqing Ye ◽

...

Keyword(s):

Inflammatory Bowel Disease ◽

Vitamin D ◽

Vitamin D Receptor ◽

Bowel Disease ◽

Molecular Mechanisms ◽

Target Genes ◽

Intestinal Inflammation ◽

Intestinal Epithelial ◽

Mouse Intestine ◽

Inflammatory Bowel

AbstractDespite the identification of several genetic factors linked to increased susceptibility to inflammatory bowel disease (IBD), underlying molecular mechanisms remain to be elucidated in detail. The ubiquitin ligases RNF20 and RNF40 mediate the monoubiquitination of histone H2B at lysine 120 (H2Bub1) and were shown to play context-dependent roles in the development of inflammation. Here, we aimed to examine the function of the RNF20/RNF40/H2Bub1 axis in intestinal inflammation in IBD patients and mouse models. For this purpose, intestinal sections from IBD patients were immunohistochemically stained for H2Bub1. Rnf20 or Rnf40 were conditionally deleted in the mouse intestine and mice were monitored for inflammation-associated symptoms. Using mRNA-seq and chromatin immunoprecipitation (ChIP)-seq, we analyzed underlying molecular pathways in primary intestinal epithelial cells (IECs) isolated from these animals and confirmed these findings in IBD resection specimens using ChIP-seq.The majority (80%) of IBD patients displayed a loss of H2Bub1 levels in inflamed areas and the intestine-specific deletion of Rnf20 or Rnf40 resulted in spontaneous colorectal inflammation in mice. Consistently, deletion of Rnf20 or Rnf40 promoted IBD-associated gene expression programs, including deregulation of various IBD risk genes in these animals. Further analysis of murine IECs revealed that H3K4me3 occupancy and transcription of the Vitamin D Receptor (Vdr) gene and VDR target genes is RNF20/40-dependent. Finally, these effects were confirmed in a subgroup of Crohn’s disease patients which displayed epigenetic and expression changes in RNF20/40-dependent gene signatures. Our findings reveal that loss of H2B monoubiquitination promotes intestinal inflammation via decreased VDR activity thereby identifying RNF20 and RNF40 as critical regulators of IBD.

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