scholarly journals Re-entry into mitosis and regeneration of intestinal stem cells through enteroblast dedifferentiation in Drosophila midguts

2021 ◽  
Author(s):  
Aiguo Tian ◽  
Virginia Morejon ◽  
Sarah Kohoutek ◽  
Yi-Chun Huang ◽  
Wu-Min Deng ◽  
...  
Keyword(s):  
Stem Cells ◽  
Pathogenic Bacteria ◽  
Growth Factor Receptor ◽  
Lineage Tracing ◽  
Intestinal Stem Cells ◽  
Stem Cell Marker ◽  
Secretory Cells ◽  
Ras Signaling ◽  
Epithelial Regeneration ◽  
Resident Stem Cells

Many adult tissues and organs including the intestine rely on resident stem cells to maintain homeostasis. In mammalian intestines, upon ablation of resident stem cells, the progenies of intestinal stem cells (ISCs) such as secretory cells and tuft cells can dedifferentiate to generate ISCs to drive epithelial regeneration, but whether and how the ISC progenies dedifferentiate to generate ISCs under physiological conditions remains unknown. Here we show that infection of pathogenic bacteria induces enteroblasts (EBs) as one type of ISC progenies to re-enter the mitotic cycle in the Drosophila intestine. The re-entry into mitosis is dependent on epithermal growth factor receptor (EGFR)-Ras signaling and ectopic activation of EGFR-Ras signaling in EBs is sufficient to drive EBs cell-autonomously to re-enter into mitosis. In addition, we examined whether EBs gain ISC identity as a prerequisite to divide, but the immunostaining with stem cell marker Delta shows that these dividing EBs do not gain ISC identity. After employing lineage tracing experiments, we further demonstrate that EBs dedifferentiate to generate functional ISCs after symmetric divisions of EBs. Together, our study in Drosophila intestines uncovers a new role of EGFR-Ras signaling in regulating re-entry into mitosis and dedifferentiation during regeneration and reveals a novel mechanism by which ISC progenies undergo dedifferentiation through a mitotic division, which has important implication to mammalian tissue homeostasis and tumorigenesis.

Epithelial Regeneration after Doxorubicin Arises Primarily from Early Progeny of Active Intestinal Stem Cells

2020 ◽  
Author(s):  
Breanna Sheahan ◽  
Ally N. Freeman ◽  
Theresa M. Keeley ◽  
Linda C. Samuelson ◽  
Jatin Roper ◽  
...  
Keyword(s):  
Stem Cells ◽  
Intestinal Stem Cells ◽  
Epithelial Regeneration

scholarly journals Taking a Step Back: Insights into the Mechanisms Regulating Gut Epithelial Dedifferentiation

2021 ◽  
Vol 22 (13) ◽  
pp. 7043
Author(s):  
Shaida Ouladan ◽  
Alex Gregorieff
Keyword(s):  
Cell Fate ◽  
Hormonal Regulation ◽  
Transcriptional Profiling ◽  
Cell Types ◽  
Lineage Tracing ◽  
Intestinal Stem Cells ◽  
Physical Damage ◽  
Epithelial Regeneration ◽  
Gut Epithelium ◽  
Stem Cell Populations

Despite the environmental constraints imposed upon the intestinal epithelium, this tissue must perform essential functions such as nutrient absorption and hormonal regulation, while also acting as a critical barrier to the outside world. These functions depend on a variety of specialized cell types that are constantly renewed by a rapidly proliferating population of intestinal stem cells (ISCs) residing at the base of the crypts of Lieberkühn. The niche components and signals regulating crypt morphogenesis and maintenance of homeostatic ISCs have been intensely studied over the last decades. Increasingly, however, researchers are turning their attention to unraveling the mechanisms driving gut epithelial regeneration due to physical damage or infection. It is now well established that injury to the gut barrier triggers major cell fate changes, demonstrating the highly plastic nature of the gut epithelium. In particular, lineage tracing and transcriptional profiling experiments have uncovered several injury-induced stem-cell populations and molecular markers of the regenerative state. Despite the progress achieved in recent years, several questions remain unresolved, particularly regarding the mechanisms driving dedifferentiation of the gut epithelium. In this review, we summarize the latest studies, primarily from murine models, that define the regenerative processes governing the gut epithelium and discuss areas that will require more in-depth investigation.

scholarly journals Immunostaining of Lgr5, an Intestinal Stem Cell Marker, in Normal and Premalignant Human Gastrointestinal Tissue

2008 ◽  
Vol 8 ◽  
pp. 1168-1176 ◽  
Author(s):  
Laren Becker ◽  
Qin Huang ◽  
Hiroshi Mashimo
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Stem Cell Niche ◽  
Intestinal Stem Cells ◽  
Stem Cell Marker ◽  
Tumor Initiating Cells ◽  
Colonic Adenomas ◽  
Potential Marker ◽  
Cell Niche ◽  
Crypt Base

Lgr5 has recently been identified as a murine marker of intestinal stem cells. Its expression has not been well characterized in human gastrointestinal tissues, but has been reported in certain cancers. With the increasing appreciation for the role of cancer stem cells or tumor-initiating cells in certain tumors, we sought to explore the expression of Lgr5 in normal and premalignant human gastrointestinal tissues. Using standard immunostaining, we compared expression of Lgr5 in normal colon and small intestine vs. small intestinal and colonic adenomas and Barrett's esophagus. In the normal tissue, Lgr5 was expressed in the expected stem cell niche, at the base of crypts, as seen in mice. However, in premalignant lesions, Lgr5+cells were not restricted to the crypt base. Additionally, their overall numbers were increased. In colonic adenomas, Lgr5+cells were commonly found clustered at the luminal surface and rarely at the crypt base. Finally, we compared immunostaining of Lgr5 with that of CD133, a previously characterized marker for tumor-initiating cells in colon cancer, and found that they identified distinct subpopulations of cells that were in close proximity, but did not costain. Our findings suggest that (1) Lgr5 is a potential marker of intestinal stem cells in humans and (2) loss of restriction to the stem cell niche is an early event in the premalignant transformation of stem cells and may play a role in carcinogenesis.

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 Mutations in long-lived epithelial stem cells and their clonal progeny in pre-malignant lesions and in oral squamous cell carcinoma

2020 ◽  
Vol 41 (11) ◽  
pp. 1553-1564
Author(s):  
Marta Melis ◽  
Tuo Zhang ◽  
Theresa Scognamiglio ◽  
Lorraine J Gudas
Keyword(s):  
Stem Cells ◽  
Cell Adhesion ◽  
Squamous Cell ◽  
Planar Cell Polarity ◽  
Molecular Mechanisms ◽  
Growth Factor Receptor ◽  
Lineage Tracing ◽  
Epithelial Stem Cells ◽  
Single Nucleotide Variants ◽  
Phosphoinositide 3 Kinase

Abstract Oral squamous cell carcinomas (OSCCs) are the most common cancers of the oral cavity, but the molecular mechanisms driving OSCC carcinogenesis remain unclear. Our group previously established a murine OSCC model based on a 10-week carcinogen [4-nitroquinoline 1-oxide (4-NQO)] treatment. Here we used K14CreERTAM;Rosa26LacZ mice to perform lineage tracing to delineate the mutational profiles in clonal cell populations resulting from single, long-lived epithelial stem cells, here called LacZ+ stem cell clones (LSCCs). Using laser-capture microdissection, we examined mutational changes in LSCCs immediately after the 10-week 4-NQO treatment and >17 weeks after 4-NQO treatment. We found a 1.8-fold ±0.4 (P = 0.009) increase in single-nucleotide variants and insertions/deletions (indels) in tumor compared with pre-neoplastic LSCCs. The percentages of indels and of loss of heterozygosity events were 1.3-fold±0.3 (P = 0.02) and 2.2-fold±0.7 (P = 0.08) higher in pre-neoplastic compared with tumor LSCCs. Mutations in cell adhesion- and development-associated genes occurred in 83% of the tumor LSCCs. Frequently mutated genes in tumor LSCCs were involved in planar cell polarity (Celsr1, Fat4) or development (Notch1). Chromosomal amplifications in 50% of the tumor LSCCs occurred in epidermal growth factor receptor, phosphoinositide 3-kinase and cell adhesion pathways. All pre-neoplastic and tumor LSCCs were characterized by key smoking-associated changes also observed in human OSCC, C>A and G>T. DeconstructSigs analysis identified smoking and head and neck cancer as the most frequent mutational signatures in pre-neoplastic and tumor LSCCs. Thus, this model recapitulates a smoking-associated mutational profile also observed in humans and illustrates the role of LSCCs in early carcinogenesis and OSCCs.

scholarly journals Intestinal epithelial cell-specific IGF1 promotes the expansion of intestinal stem cells during epithelial regeneration and functions on the intestinal immune homeostasis

2018 ◽  
Vol 315 (4) ◽  
pp. E638-E649 ◽  
Author(s):  
Yu Zheng ◽  
Yongli Song ◽  
Qi Han ◽  
Wenjie Liu ◽  
Jiuzhi Xu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Epithelial Cell ◽  
Intestinal Epithelial Cell ◽  
High Throughput Sequencing ◽  
Secretory Cells ◽  
Intestinal Epithelial ◽  
Epithelial Stem Cells ◽  
Microbial Composition ◽  
Epithelial Regeneration

It is well known that insulin-like growth factor 1 (IGF1) acts as a trophic factor in small intestine under both physiological and pathophysiological conditions. However, it still lacks direct in vivo evidence of the functions of intestinal epithelial cell (IEC)-specific IGF1 under both normal and pathological conditions. Using IEC-specific IGF1-knockout (cKO) mice and Lgr5-eGFP-CreERT mice, we demonstrate that IEC-specific IGF1 can enhance nutrient uptake, reduce protein catabolism and energy consumption, and promote the proliferation and expansion of intestinal epithelial cells, including intestinal epithelial stem cells and intestinal secretory cells. Next, we showed that IEC-specific IGF1 renders IECs resistant to irradiation and promotes epithelial regeneration. Strikingly, transcriptome profiling assay revealed that many differentially expressed genes involved in the differentiation and maturation of lymphoid lineages were significantly suppressed in the cKO mice as compared with the control mice. We demonstrated that deletion of IGF1 in IECs enhances bacterial translocation to the mesenteric lymph nodes and liver. Furthermore, high-throughput sequencing of 16S ribosomal RNA genes of gut microbiota revealed that IEC-specific IGF1 loss profoundly affected the gut microbial composition at various levels of classification. Therefore, our findings shed light on the in vivo roles of IEC-specific IGF1 in intestinal homeostasis, epithelial regeneration, and immunity, broadening our current insights on IGF1 functions.

scholarly journals Injury-stimulated Hedgehog signaling promotes regenerative proliferation of Drosophila intestinal stem cells

2015 ◽  
Vol 208 (6) ◽  
pp. 807-819 ◽  
Author(s):  
Aiguo Tian ◽  
Qing Shi ◽  
Alice Jiang ◽  
Shuangxi Li ◽  
Bing Wang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Hedgehog Signaling ◽  
Intestinal Stem Cells ◽  
Homeostatic Proliferation ◽  
Jnk Pathway ◽  
Signaling Axis ◽  
Resident Stem Cells ◽  
Hh Signaling ◽  
Stat Pathway

Many adult tissues are maintained by resident stem cells that elevate their proliferation in response to injury. The regulatory mechanisms underlying regenerative proliferation are still poorly understood. Here we show that injury induces Hedgehog (Hh) signaling in enteroblasts (EBs) to promote intestinal stem cell (ISC) proliferation in Drosophila melanogaster adult midgut. Elevated Hh signaling by patched (ptc) mutations drove ISC proliferation noncell autonomously. Inhibition of Hh signaling in the ISC lineage compromised injury-induced ISC proliferation but had little if any effect on homeostatic proliferation. Hh signaling acted in EBs to regulate the production of Upd2, which activated the JAK–STAT pathway to promote ISC proliferation. Furthermore, we show that Hh signaling is stimulated by DSS through the JNK pathway and that inhibition of Hh signaling in EBs prevented DSS-stimulated ISC proliferation. Hence, our study uncovers a JNK–Hh–JAK–STAT signaling axis in the regulation of regenerative stem cell proliferation.

scholarly journals Mouse telomerase reverse transcriptase (mTert) expression marks slowly cycling intestinal stem cells

2010 ◽  
Vol 108 (1) ◽  
pp. 179-184 ◽  
Author(s):  
Robert K. Montgomery ◽  
Diana L. Carlone ◽  
Camilla A. Richmond ◽  
Loredana Farilla ◽  
Mariette E. G. Kranendonk ◽  
...  
Keyword(s):  
Stem Cells ◽  
Reverse Transcriptase ◽  
Tissue Injury ◽  
Cell Types ◽  
Lineage Tracing ◽  
Intestinal Stem Cells ◽  
Intestinal Cell ◽  
Stem Cell Population ◽  
Telomerase Reverse Transcriptase

The intestinal epithelium is maintained by a population of rapidly cycling (Lgr5+) intestinal stem cells (ISCs). It has been postulated, however, that slowly cycling ISCs must also be present in the intestine to protect the genome from accumulating deleterious mutations and to allow for a response to tissue injury. Here, we identify a subpopulation of slowly cycling ISCs marked by mouse telomerase reverse transcriptase (mTert) expression that can give rise to Lgr5+ cells. mTert-expressing cells distribute in a pattern along the crypt–villus axis similar to long-term label-retaining cells (LRCs) and are resistant to tissue injury. Lineage-tracing studies demonstrate that mTert+ cells give rise to all differentiated intestinal cell types, persist long term, and contribute to the regenerative response following injury. Consistent with other highly regenerative tissues, our results demonstrate that a slowly cycling stem cell population exists within the intestine.

scholarly journals Platelet-Derived Growth Factor Receptor Alpha as a Marker of Mesenchymal Stem Cells in Development and Stem Cell Biology

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Ramin M. Farahani ◽  
Munira Xaymardan
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Stem Cell ◽  
Cell Biology ◽  
Growth Factor Receptor ◽  
Stem Cell Marker ◽  
Factor Receptor Alpha ◽  
Lines Of Evidence

Three decades on, the mesenchymal stem cells (MSCs) have been intensively researched on the bench top and used clinically. However, ambiguity still exists in regard to their anatomical locations, identities, functions, and extent of their differentiative abilities. One of the major impediments in the quest of the MSC research has been lack of appropriatein vivomarkers. In recent years, this obstacle has been resolved to some degree as PDGFRαemerges as an important mesenchymal stem cell marker. Accumulating lines of evidence are showing that the PDGFRα+cells reside in the perivascular locations of many adult interstitium and fulfil the classic concepts of MSCsin vitroandin vivo. PDGFRαhas long been recognised for its roles in the mesoderm formation and connective tissue development during the embryogenesis. Current review describes the lines of evidence regarding the role of PDGFRαin morphogenesis and differentiation and its implications for MSC biology.

scholarly journals Lipogems Product Treatment Increases the Proliferation Rate of Human Tendon Stem Cells without Affecting Their Stemness and Differentiation Capability

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Pietro Randelli ◽  
Alessandra Menon ◽  
Vincenza Ragone ◽  
Pasquale Creo ◽  
Sonia Bergante ◽  
...  
Keyword(s):  
Stem Cells ◽  
Rotator Cuff ◽  
Healing Process ◽  
Cost Effective ◽  
Proliferation Rate ◽  
Stem Cell Marker ◽  
Bone Marrow Biopsies ◽  
Resident Stem Cells ◽  
Tendon Stem Cells ◽  
Human Tendon

Increasing the success rate of rotator cuff healing remains tremendous challenge. Among many approaches, the possibility of activating resident stem cells in situ, without the need to isolate them from biopsies, could represent valuable therapeutic strategy. Along this line, it has been recently demonstrated that lipoaspirate product, Lipogems, contains and produces growth-factors that may activate resident stem cells. In this study, human tendon stem cells (hTSCs) from the rotator cuff were cocultured in a transwell system with the Lipogems lipoaspirate product and compared to control untreated cells in terms of cell proliferation, morphology, stem cell marker and VEGF expression, and differentiation and migration capabilities. Results showed that the Lipogems product significantly increases the proliferation rate of hTSCs without altering their stemness and differentiation capability. Moreover, treated cells increase the expression of VEGF, which is crucial for the neovascularization of the tissue during the healing process. Overall, this study supports that directly activating hTSCs with the Lipogems lipoaspirate could represent a new practical therapeutic approach. In fact, obtaining a lipoaspirate is easier, safer, and more cost-effective than harvesting cells from tendon or bone marrow biopsies, expanding them in GMP facility and then reinjecting them in the patient.

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