scholarly journals DOT1L-Mediated H3K79 Methylation in Chromatin Is Dispensable for Wnt Pathway-Specific and Other Intestinal Epithelial Functions

2013 ◽  
Vol 33 (9) ◽  
pp. 1735-1745 ◽  
Author(s):  
Li-Lun Ho ◽  
Amit Sinha ◽  
Michael Verzi ◽  
Kathrin M. Bernt ◽  
Scott A. Armstrong ◽  
...  
Keyword(s):  
Stem Cells ◽  
Intestinal Epithelium ◽  
Target Genes ◽  
Intestinal Stem Cells ◽  
Intestinal Epithelial ◽  
Aberrant Expression ◽  
Genome Wide ◽  
Transcript Profiles ◽  
H3k79 Methylation

Methylation of H3K79 is associated with chromatin at expressed genes, though it is unclear if this histone modification is required for transcription of all genes. Recent studies suggest that Wnt-responsive genes depend particularly on H3K79 methylation, which is catalyzed by the methyltransferase DOT1L. Human leukemias carrying MLL gene rearrangements show DOT1L-mediated H3K79 methylation and aberrant expression of leukemogenic genes. DOT1L inhibitors reverse these effects, but their clinical use is potentially limited by toxicity in Wnt-dependent tissues such as intestinal epithelium. Genome-wide positioning of the H3K79me2 mark in Lgr5 + mouse intestinal stem cells and mature intestinal villus epithelium correlated with expression levels of all transcripts and not with Wnt-responsive genes per se . Selective Dot1l disruption in Lgr5 + stem cells or in whole intestinal epithelium eliminated H3K79me2 from the respective compartments, allowing genetic evaluation of DOT1L requirements. The absence of methylated H3K79 did not impair health, intestinal homeostasis, or expression of Wnt target genes in crypt epithelium for up to 4 months, despite increased crypt cell apoptosis. Global transcript profiles in Dot1l -null cells were barely altered. Thus, H3K79 methylation is not essential for transcription of Wnt-responsive or other intestinal genes, and intestinal toxicity is not imperative when DOT1L is rendered inactive in vivo .

scholarly journals Source and Impact of the EGF Family of Ligands on Intestinal Stem Cells

2021 ◽  
Vol 9 ◽  
Author(s):  
Helen E. Abud ◽  
Wing Hei Chan ◽  
Thierry Jardé
Keyword(s):  
Stem Cells ◽  
Growth Factor ◽  
Ex Vivo ◽  
Intestinal Stem Cells ◽  
Intestinal Epithelial ◽  
Neuregulin 1 ◽  
Epithelial Development ◽  
Epidermal Growth ◽  
Egf Family

Epidermal Growth Factor (EGF) has long been known for its role in promoting proliferation of intestinal epithelial cells. EGF is produced by epithelial niche cells at the base of crypts in vivo and is routinely added to the culture medium to support the growth of intestinal organoids ex vivo. The recent identification of diverse stromal cell populations that reside underneath intestinal crypts has enabled the characterization of key growth factor cues supplied by these cells. The nature of these signals and how they are delivered to drive intestinal epithelial development, daily homeostasis and tissue regeneration following injury are being investigated. It is clear that aside from EGF, other ligands of the family, including Neuregulin 1 (NRG1), have distinct roles in supporting the function of intestinal stem cells through the ErbB pathway.

scholarly journals Prrx1 promotes stemness and angiogenesis via activating TGF-β/smad pathway and upregulating proangiogenic factors in glioma

2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Zetao Chen ◽  
Yihong Chen ◽  
Yan Li ◽  
Weidong Lian ◽  
Kehong Zheng ◽  
...  
Keyword(s):  
Stem Cells ◽  
Therapeutic Strategy ◽  
Critical Role ◽  
Glioma Stem Cells ◽  
Promoter Regions ◽  
Aberrant Expression ◽  
Smad Pathway ◽  
Tgf Β1

AbstractGlioma is one of the most lethal cancers with highly vascularized networks and growing evidences have identified glioma stem cells (GSCs) to account for excessive angiogenesis in glioma. Aberrant expression of paired-related homeobox1 (Prrx1) has been functionally associated with cancer stem cells including GSCs. In this study, Prrx1 was found to be markedly upregulated in glioma specimens and elevated Prrx1 expression was inversely correlated with prognosis of glioma patients. Prrx1 potentiated stemness acquisition in non-stem tumor cells (NSTCs) and stemness maintenance in GSCs, accompanied with increased expression of stemness markers such as SOX2. Prrx1 also promoted glioma angiogenesis by upregulating proangiogenic factors such as VEGF. Consistently, silencing Prrx1 markedly inhibited glioma proliferation, stemness, and angiogenesis in vivo. Using a combination of subcellular proteomics and in vitro analyses, we revealed that Prrx1 directly bound to the promoter regions of TGF-β1 gene, upregulated TGF-β1 expression, and ultimately activated the TGF-β/smad pathway. Silencing TGF-β1 mitigated the malignant behaviors induced by Prrx1. Activation of this pathway cooperates with Prrx1 to upregulate the expression of stemness-related genes and proangiogenic factors. In summary, our findings revealed that Prrx1/TGF-β/smad signal axis exerted a critical role in glioma stemness and angiogeneis. Disrupting the function of this signal axis might represent a new therapeutic strategy in glioma patients.

scholarly journals Genome-Wide Binding Analyses of HOXB1 Revealed a Novel DNA Binding Motif Associated with Gene Repression

2021 ◽  
Vol 9 (1) ◽  
pp. 6
Author(s):  
Narendra Pratap Singh ◽  
Bony De Kumar ◽  
Ariel Paulson ◽  
Mark E. Parrish ◽  
Carrie Scott ◽  
...  
Keyword(s):  
Dna Binding ◽  
Target Genes ◽  
Embryonic Stem ◽  
Binding Motif ◽  
Binding Assays ◽  
Histone Marks ◽  
Genome Wide ◽  
Hox Cofactors

Knowledge of the diverse DNA binding specificities of transcription factors is important for understanding their specific regulatory functions in animal development and evolution. We have examined the genome-wide binding properties of the mouse HOXB1 protein in embryonic stem cells differentiated into neural fates. Unexpectedly, only a small number of HOXB1 bound regions (7%) correlate with binding of the known HOX cofactors PBX and MEIS. In contrast, 22% of the HOXB1 binding peaks display co-occupancy with the transcriptional repressor REST. Analyses revealed that co-binding of HOXB1 with PBX correlates with active histone marks and high levels of expression, while co-occupancy with REST correlates with repressive histone marks and repression of the target genes. Analysis of HOXB1 bound regions uncovered enrichment of a novel 15 base pair HOXB1 binding motif HB1RE (HOXB1 response element). In vitro template binding assays showed that HOXB1, PBX1, and MEIS can bind to this motif. In vivo, this motif is sufficient for direct expression of a reporter gene and over-expression of HOXB1 selectively represses this activity. Our analyses suggest that HOXB1 has evolved an association with REST in gene regulation and the novel HB1RE motif contributes to HOXB1 function in part through a repressive role in gene expression.

scholarly journals Cdx2 regulates immune cell infiltration in the intestine

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Simon Chewchuk ◽  
Sanzida Jahan ◽  
David Lohnes
Keyword(s):  
Intestinal Epithelium ◽  
Target Genes ◽  
Immune Cell ◽  
Cell Number ◽  
Macrophage Infiltration ◽  
Intestinal Homeostasis ◽  
Chronic Inflammatory Response ◽  
Complex Protein ◽  
Inflammatory Phenotype

AbstractThe intestinal epithelium is a unique tissue, serving both as a barrier against pathogens and to conduct the end digestion and adsorption of nutrients. As regards the former, the intestinal epithelium contains a diverse repertoire of immune cells, including a variety of resident lymphocytes, macrophages and dendritic cells. These cells serve a number of roles including mitigation of infection and to stimulate regeneration in response to damage. The transcription factor Cdx2, and to a lesser extent Cdx1, plays essential roles in intestinal homeostasis, and acts as a context-dependent tumour suppressor in colorectal cancer. Deletion of Cdx2 from the murine intestinal epithelium leads to macrophage infiltration resulting in a chronic inflammatory response. However the mechanisms by which Cdx2 loss evokes this response are poorly understood. To better understand this relationship, we used a conditional mouse model lacking all intestinal Cdx function to identify potential target genes which may contribute to this inflammatory phenotype. One such candidate encodes the histocompatability complex protein H2-T3, which functions to regulate intestinal iCD8α lymphocyte activity. We found that Cdx2 occupies the H3-T3 promoter in vivo and directly regulates its expression via a Cdx response element. Loss of Cdx function leads to a rapid and pronounced attenuation of H2-T3, followed by a decrease in iCD8α cell number, an increase in macrophage infiltration and activation of pro-inflammatory cascades. These findings suggest a previously unrecognized role for Cdx in intestinal homeostasis through H2-T3-dependent regulation of iCD8α cells.

scholarly journals Genome-wide CRISPR-Cas9 screen identified KLF11 as a druggable suppressor for sarcoma cancer stem cells

2021 ◽  
Vol 7 (5) ◽  
pp. eabe3445
Author(s):  
Yicun Wang ◽  
Jinhui Wu ◽  
Hui Chen ◽  
Yang Yang ◽  
Chengwu Xiao ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cancer Stem Cells ◽  
Negative Feedback ◽  
Direct Interaction ◽  
Therapy Resistance ◽  
Negative Regulator ◽  
Chemotherapy Response ◽  
Genome Wide

Cancer stem cells (CSCs) are involved in tumorigenesis, recurrence, and therapy resistance. To identify critical regulators of sarcoma CSCs, we performed a reporter-based genome-wide CRISPR-Cas9 screen and uncovered Kruppel-like factor 11 (KLF11) as top candidate. In vitro and in vivo functional annotation defined a negative role of KLF11 in CSCs. Mechanistically, KLF11 and YAP/TEAD bound to adjacent DNA sites along with direct interaction. KLF11 recruited SIN3A/HDAC to suppress the transcriptional output of YAP/TEAD, which, in turn, promoted KLF11 transcription, forming a negative feedback loop. However, in CSCs, this negative feedback was lost because of epigenetic silence of KLF11, causing sustained YAP activation. Low KLF11 was associated with poor prognosis and chemotherapy response in patients with sarcoma. Pharmacological activation of KLF11 by thiazolidinedione effectively restored chemotherapy response. Collectively, our study identifies KLF11 as a negative regulator in sarcoma CSCs and potential therapeutic target.

Genome-wide analysis of familial dysautonomia and kinetin target genes with patient olfactory ecto-mesenchymal stem cells

2012 ◽  
Vol 33 (3) ◽  
pp. 530-540 ◽  
Author(s):  
Nathalie Boone ◽  
Aurélie Bergon ◽  
Béatrice Loriod ◽  
Arnaud Devèze ◽  
Catherine Nguyen ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Target Genes ◽  
Familial Dysautonomia ◽  
Genome Wide Analysis ◽  
Genome Wide

scholarly journals Epithelial argininosuccinate synthetase is dispensable for intestinal regeneration and tumorigenesis

2021 ◽  
Vol 12 (10) ◽  
Author(s):  
Jonathan H. M. van der Meer ◽  
Ruben J. de Boer ◽  
Bartolomeus J. Meijer ◽  
Wouter L. Smit ◽  
Jacqueline L. M. Vermeulen ◽  
...  
Keyword(s):  
Amino Acid ◽  
Intestinal Epithelium ◽  
De Novo ◽  
Cell Types ◽  
Intestinal Epithelial ◽  
Argininosuccinate Synthetase ◽  
Important Amino Acid ◽  
Tissue Specimens ◽  
Colorectal Cancer Patients

AbstractThe epithelial signaling pathways involved in damage and regeneration, and neoplastic transformation are known to be similar. We noted upregulation of argininosuccinate synthetase (ASS1) in hyperproliferative intestinal epithelium. Since ASS1 leads to de novo synthesis of arginine, an important amino acid for the growth of intestinal epithelial cells, its upregulation can contribute to epithelial proliferation necessary to be sustained during oncogenic transformation and regeneration. Here we investigated the function of ASS1 in the gut epithelium during tissue regeneration and tumorigenesis, using intestinal epithelial conditional Ass1 knockout mice and organoids, and tissue specimens from colorectal cancer patients. We demonstrate that ASS1 is strongly expressed in the regenerating and Apc-mutated intestinal epithelium. Furthermore, we observe an arrest in amino acid flux of the urea cycle, which leads to an accumulation of intracellular arginine. However, loss of epithelial Ass1 does not lead to a reduction in proliferation or increase in apoptosis in vivo, also in mice fed an arginine-free diet. Epithelial loss of Ass1 seems to be compensated by altered arginine metabolism in other cell types and the liver.

scholarly journals Inflammation- and Gut-Homing Macrophages, Engineered to De Novo Overexpress Active Vitamin D, Promoted the Regenerative Function of Intestinal Stem Cells

2021 ◽  
Vol 22 (17) ◽  
pp. 9516
Author(s):  
Yi Xu ◽  
David J. Baylink ◽  
Huynh Cao ◽  
Jeffrey Xiao ◽  
Maisa I. Abdalla ◽  
...  
Keyword(s):  
Stem Cells ◽  
Vitamin D ◽  
De Novo ◽  
Chronic Inflammatory Disease ◽  
Intestinal Stem Cells ◽  
Intestinal Epithelial ◽  
Active Vitamin ◽  
Gut Inflammation ◽  
Epithelial Regeneration ◽  
Active Vitamin D

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gut. Available drugs aim to suppress gut inflammation. These drugs have significantly delayed disease progression and improved patients’ quality of life. However, the disease continues to progress, underscoring the need to develop novel therapies. Aside from chronic gut inflammation, IBD patients also experience a leaky gut problem due to damage to the intestinal epithelial layer. In this regard, epithelial regeneration and repair are mediated by intestinal stem cells. However, no therapies are available to directly enhance the intestinal stem cells’ regenerative and repair function. Recently, it was shown that active vitamin D, i.e., 1,25-dihydroxyvitamin D or 1,25(OH)2D, was necessary to maintain Lgr5+ intestinal stem cells, actively cycling under physiological conditions. In this study, we used two strategies to investigate the role of 1,25(OH)2D in intestinal stem cells’ regenerative function. First, to avoid the side effects of systemic high 1,25(OH)2D conditions, we used our recently developed novel strategy to deliver locally high 1,25(OH)2D concentrations specifically to inflamed intestines. Second, because of the Lgr5+ intestinal stem cells’ active cycling status, we used a pulse-and-chase strategy via 5-bromo-2′-deoxyuridine (BrdU) labeling to trace the Lgr5+ stem cells through the whole epithelial regeneration process. Our data showed that locally high 1,25(OH)2D concentrations enhanced intestinal stem cell migration. Additionally, the migrated cells differentiated into mature epithelial cells. Our data, therefore, suggest that local delivery of high 1,25(OH)2D concentrations is a promising strategy to augment intestinal epithelial repair in IBD patients.

scholarly journals Unveiling role of Sphingosine-1-phosphate receptor 2 as a brake of epithelial stem cell proliferation and a tumor suppressor in colorectal cancer

2020 ◽  
Author(s):  
Luciana Petti ◽  
Giulia Rizzo ◽  
Federica Rubbino ◽  
Sudharshan Elangovan ◽  
Piergiuseppe Colombo ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Proliferation ◽  
Normal Mucosa ◽  
Genetically Engineered ◽  
Colorectal Carcinogenesis ◽  
Intestinal Stem Cells ◽  
Cancer Information ◽  
Intestinal Epithelial ◽  
Epithelial Stem Cells ◽  
Mucosal Regeneration

Abstract BackgroundSphingosine-1-phosphate receptor 2 (S1PR2) mediates pleiotropic functions encompassing cell proliferation, survival, and migration, which become collectively de-regulated in cancer. Information onto whether S1PR2 participates in colorectal carcinogenesis/cancer is scanty, and we set out to fill the gap.MethodsWe screened expression changes of S1PR2 in human CRC and matched normal mucosa specimens [N = 76]. We compared CRC arising in inflammation-driven and genetically engineered models in wild-type (S1PR2+/+) and S1PR2 deficient (S1PR2−/−) mice. We reconstituted S1PR2 expression in RKO cells and assessed their growth in xenografts. Functionally, we mimicked ablation of S1PR2 in normal mucosa by treating S1PR2+/+ organoids with JTE013, and characterized intestinal epithelial stem cells isolated from S1PR2−/−Lgr5-EGFP- mice.ResultsS1PR2 expression was lost in 33% of CRC; in 55%, it was significantly decreased, only 12% retaining expression comparable to normal mucosa. Both colitis-induced and genetic Apc+/min mouse models of CRC showed a higher incidence in size and number of carcinomas and/or high-grade adenomas, with increased cell proliferation in S1PR2−/− mice compared to S1PR2+/+ controls. Loss of S1PR2 impaired mucosal regeneration, ultimately promoting the expansion of intestinal stem cells. Whereas its overexpression attenuated cell cycle progression, it reduced the phosphorylation of AKT and augmented the levels of PTEN.ConclusionsIn normal colonic crypts, S1PR2 gains expression along with intestinal epithelial cells differentiation, but not in intestinal stem cells, and contrasts intestinal tumorigenesis by promoting epithelial differentiation, preventing the expansion of stem cells and braking their malignant transformation. Targeting of S1PR2 may be of therapeutic benefit for CRC expressing high Lgr5.

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