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 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 Antibody-Dye Conjugate Detects Epidermal Growth Factor Receptor Expression in High-Graded Gliomas: A Feasibility Study for Fluorescence-Guided Resection

2020 ◽  
Author(s):  
Quan Zhou ◽  
Johana Vega Leonel ◽  
Michelle Santoso ◽  
Christy Wilson ◽  
Nynke van den Berg ◽  
...  
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Near Infrared ◽  
Ex Vivo ◽  
Growth Factor Receptor ◽  
Egfr Expression ◽  
Epidermal Growth ◽  
Specific Uptake

Abstract Background: The prognosis for high-grade glioma (HGG) remains dismal and extent of resection correlates with overall survival and progression free disease. Epidermal growth factor receptor (EGFR) is a biomarker heterogeneously expressed in HGG. We assessed the feasibility of detecting HGG using near-infrared fluorescent antibody targeting EGFR. Methods: Mice bearing orthotopic HGG xenografts with modest EGFR expression were imaged in vivo after systemic panitumumab-IRDye800 injection to assess its tumor-specific uptake macroscopically over 14 days, and microscopically ex vivo. EGFR immunohistochemical staining of 59 tumor specimens from 35 HGG patients during was scored by pathologists and expression levels were compared to that of mouse xenografts. Results: Intratumoral distribution of pan800 correlated with near-infrared fluorescence and EGFR expression. Fluorescence distinguished tumor cells with 90% specificity and 82.5% sensitivity. Target-to-background ratios peaked at 14 hours post panitumumab-IRDye800 infusion, reaching 19.5 in vivo and 7.6 ex vivo, respectively. Equivalent or higher EGFR protein expression compared to the mouse xenografts was present in 77.1% HGG patients. Age, combined with IDH-wildtype cerebral tumor, was predictive of greater EGFR protein expression in human tumors. Conclusion: Tumor specific uptake of pan800 provided remarkable contrast and a flexible imaging window for fluorescence-guided identification of HGGs despite modest EGFR expression.

scholarly journals High glucose concentration in cell culture medium does not acutely affect human mesenchymal stem cell growth factor production or proliferation

2009 ◽  
Vol 296 (6) ◽  
pp. R1735-R1743 ◽  
Author(s):  
Brent R. Weil ◽  
Aaron M. Abarbanell ◽  
Jeremy L. Herrmann ◽  
Yue Wang ◽  
Daniel R. Meldrum
Keyword(s):  
Stem Cells ◽  
Growth Factor ◽  
High Glucose ◽  
Glucose Concentration ◽  
Ex Vivo ◽  
Response To Treatment ◽  
Brdu Incorporation ◽  
Therapeutic Benefits ◽  
Tnf Α

Optimizing the function and proliferative capacity of stem cells is essential to maximize their therapeutic benefits. High glucose concentrations are known to have detrimental effects on many cell types. We hypothesized that human mesenchymal stem cells (hMSCs) cultured in high glucose-containing media would exhibit diminished proliferation and attenuated production of VEGF, hepatocyte growth factor (HGF), and FGF2 in response to treatment with TNF-α, LPS, or hypoxia. hMSCs were plated in medium containing low (5.5 mM) and high (20 mM or 30 mM) glucose concentrations and treated with TNF-α, LPS, or hypoxia. Supernatants were collected at 24 and 48 h and assayed via ELISA for VEGF, HGF, and FGF2. In addition, hMSCs were cultured on 96-well plates at the above glucose concentrations, and proliferation at 48 h was determined via bromo-2′-deoxy-uridine (BrdU) incorporation. At 24 and 48 h, TNF-α, LPS, and hypoxia-treated hMSCs produced significantly higher VEGF, HGF, and FGF2 compared with control. Hypoxia-induced VEGF production by hMSCs was the most pronounced change over baseline. At both 24 and 48 h, glucose concentration did not affect production of VEGF, HGF, or FGF2 by untreated hMSCs and those treated with TNF-α, LPS, or hypoxia. Proliferation of hMSCs as determined via BrdU incorporation was unaffected by glucose concentration of the media. Contrary to what has been observed with other cells, hMSCs may be resistant to the short-term effects of high glucose. Ongoing efforts to characterize and optimize ex vivo and in vivo conditions are critical if the therapeutic benefits of MSCs are to be maximized.

scholarly journals Epidermal Growth Factor as a Candidate for Ex Vivo Expansion of Bone Marrow-Derived Mesenchymal Stem Cells

Stem Cells ◽  
2006 ◽  
Vol 24 (3) ◽  
pp. 686-695 ◽  
Author(s):  
Kenichi Tamama ◽  
Vivian H. Fan ◽  
Linda G. Griffith ◽  
Harry C. Blair ◽  
Alan Wells
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Ex Vivo ◽  
Ex Vivo Expansion ◽  
Epidermal Growth

scholarly journals PSIX-30 mTORC1 Sensing Glutamate Signal to Promote Porcine Intestinal Development by Accelerating Intestinal Stem Cell Expansion

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 334-335
Author(s):  
Min Zhu ◽  
Ying-chao Qin ◽  
Jia-yi Zhou ◽  
Chun-qi Gao ◽  
Hui-chao Yan ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Underlying Mechanism ◽  
Control Group ◽  
Intestinal Epithelial ◽  
Intestinal Development ◽  
Villus Height ◽  
Large White ◽  
Epithelial Development ◽  
Mtorc1 Signaling

Abstract Mechanistic target of rapamycin complex 1 (mTORC1) coordinates cell growth and metabolism with environmental cues, such as amino acids, growth factors, and energy. Glutamate (Glu) is a primary metabolic fuel for the intestinal epithelium and extensively involves numerous physiological processes. Crypt intestinal stem cells (ISCs) driven intestinal epithelial renewal that needs a continuous energy supplement. However, the effects of Glu on the expansion of porcine ISCs and intestinal epithelial development remain unclear. Therefore, the objective of this study was to investigate the underlying mechanism that Glu promotes intestinal development. Firstly, a total of 14 weaned piglets (Duroc × Landrace × Large White) with similar body weight (BW) were randomly allocated into the control group, and the 1.0% Glu group with 7 replicates per group and 1 piglet per replicate. The experiment lasts for 21 days. The results showed that dietary Glu increased small intestinal weights, jejunal villus height, and the ratio of the villus height to the crypt depth. Moreover, dietary Glu promoted the proliferation and differentiation of intestinal epithelial cells. Subsequently, iTRAQ proteomics screening indicated that intestinal mTORC1 signaling may participate in Glu-stimulated intestinal epithelial development, which was confirmed by Western blotting. Meanwhile, the IR/IRS/PI3K/Akt pathway and EGFR/ERK pathway are the upstream of Glu-induced mTORC1 signaling activation, which verified in IPEC-J2 cell line and intestinal organoids. Furthermore, the in vivo and ex vivo crypt ISCs experiments showed that Glu accelerated ISC expansion as increased intestinal organoid forming efficiency and budding efficiency. Glu also promoted ISC self-renew and differentiated into various functional cells (enterocytes, goblet cells, enteroendocrine cells, Paneth cells). In summary, mTORC1 integrated Glu signal stimulated ISC expansion and ultimately promoted epithelial development.

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