1
|
Su H, Xiao Z, Yu K, Zhang Q, Lu C, Wang G, Wang Y, Liang J, Huang W, Huang X, Wei F. Use of a purified β-glucosidase from coral-associated microorganisms to enhance wine aroma. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2022; 102:3467-3474. [PMID: 34841541 DOI: 10.1002/jsfa.11694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 11/24/2021] [Accepted: 11/28/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND β-Glucosidases (3.2.1.21) play essential roles in the removal of nonreducing terminal glucosyl residues from saccharides and glycosides. However, the full potential and different applications of recombinant high-yield microbial β-glucosidase-producing systems remain to be tackled. RESULTS A β-glucosidase gene designated as Mg132 was isolated from a coral microorganism by high-throughput sequencing and functional screening. The deduced amino acid sequences of Mg132 showed a highest identity of 97% with β-glucosidase predicted in the GenBank database. This gene was cloned and overexpressed in Escherichia coli BL21 (DE3) for the first time. The optimal pH and temperature of purified recombinant Mg132 were 8.0 and 50 °C respectively. It exhibited a high level of stability at high concentration of glucose and ethanol, and glucose concentrations below 300 mmol L-1 distinctly stimulated p-nitrophenyl-β-d-glucopyranoside hydrolysis, reaching 200% at 15% ethanol. The Km and Vmax values were 0.293 mmol L-1 and 320 μmol min-1 mg-1 respectively while using p-nitrophenyl-β-d-glucopyranoside as a substrate. Wine treated with Mg132 had an obvious positive catalytic specificity for glycosides, which give a pleasant flavor of temperate fruity and floral aromas. The total concentration of fermentative volatiles was 201.42 ± 10.22 μg L-1 following Mg132 treatment and 99.21 ± 7.72 μg L-1 in control samples. CONCLUSION Good tolerance of winemaking and aroma fermentative properties suggest that Mg132 has potential application in aroma enhancement in wine and warrants further study. © 2021 Society of Chemical Industry.
Collapse
Affiliation(s)
- Hongfei Su
- Coral Reef Research Center of China, Guangxi University, Nanning, China
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, China
- School of Marine Sciences, Guangxi University, Nanning, China
| | - Zhenlun Xiao
- Coral Reef Research Center of China, Guangxi University, Nanning, China
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, China
- School of Marine Sciences, Guangxi University, Nanning, China
| | - Kefu Yu
- Coral Reef Research Center of China, Guangxi University, Nanning, China
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, China
- School of Marine Sciences, Guangxi University, Nanning, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China
| | - Qi Zhang
- Coral Reef Research Center of China, Guangxi University, Nanning, China
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, China
- School of Marine Sciences, Guangxi University, Nanning, China
| | - Chunrong Lu
- Coral Reef Research Center of China, Guangxi University, Nanning, China
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, China
- School of Marine Sciences, Guangxi University, Nanning, China
| | - Guanghua Wang
- Coral Reef Research Center of China, Guangxi University, Nanning, China
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, China
- School of Marine Sciences, Guangxi University, Nanning, China
| | - Yinghui Wang
- Coral Reef Research Center of China, Guangxi University, Nanning, China
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, China
- School of Marine Sciences, Guangxi University, Nanning, China
| | - Jiayuan Liang
- Coral Reef Research Center of China, Guangxi University, Nanning, China
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, China
- School of Marine Sciences, Guangxi University, Nanning, China
| | - Wen Huang
- Coral Reef Research Center of China, Guangxi University, Nanning, China
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, China
- School of Marine Sciences, Guangxi University, Nanning, China
| | - Xueyong Huang
- Coral Reef Research Center of China, Guangxi University, Nanning, China
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, China
- School of Marine Sciences, Guangxi University, Nanning, China
| | - Fen Wei
- Coral Reef Research Center of China, Guangxi University, Nanning, China
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Guangxi University, Nanning, China
- School of Marine Sciences, Guangxi University, Nanning, China
| |
Collapse
|
2
|
Retinoic Acid Is Required for Neural Stem and Progenitor Cell Proliferation in the Adult Hippocampus. Stem Cell Reports 2018; 10:1705-1720. [PMID: 29805108 PMCID: PMC5993652 DOI: 10.1016/j.stemcr.2018.04.024] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 04/26/2018] [Accepted: 04/26/2018] [Indexed: 01/19/2023] Open
Abstract
Neural stem and precursor cell (NSPC) proliferation in the rodent adult hippocampus is essential to maintain stem cell populations and produce new neurons. Retinoic acid (RA) signaling is implicated in regulation of adult hippocampal neurogenesis, but its exact role in control of NSPC behavior has not been examined. We show RA signaling in all hippocampal NSPC subtypes and that inhibition of RA synthesis or signaling significantly decreases NSPC proliferation via abrogation of cell-cycle kinetics and cell-cycle regulators. RA signaling controls NSPC proliferation through hypoxia inducible factor-1α (HIF1α), where stabilization of HIF1α concurrent with disruption of RA signaling can prevent NSPC defects. These studies demonstrate a cell-autonomous role for RA signaling in hippocampal NSPCs that substantially broadens RA's function beyond its well-described role in neuronal differentiation.
Collapse
|
3
|
Huels DJ, Bruens L, Hodder MC, Cammareri P, Campbell AD, Ridgway RA, Gay DM, Solar-Abboud M, Faller WJ, Nixon C, Zeiger LB, McLaughlin ME, Morrissey E, Winton DJ, Snippert HJ, van Rheenen J, Sansom OJ. Wnt ligands influence tumour initiation by controlling the number of intestinal stem cells. Nat Commun 2018; 9:1132. [PMID: 29556067 PMCID: PMC5859272 DOI: 10.1038/s41467-018-03426-2] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 02/13/2018] [Indexed: 01/08/2023] Open
Abstract
Many epithelial stem cell populations follow a pattern of stochastic stem cell divisions called 'neutral drift'. It is hypothesised that neutral competition between stem cells protects against the acquisition of deleterious mutations. Here we use a Porcupine inhibitor to reduce Wnt secretion at a dose where intestinal homoeostasis is maintained despite a reduction of Lgr5+ stem cells. Functionally, there is a marked acceleration in monoclonal conversion, so that crypts become rapidly derived from a single stem cell. Stem cells located further from the base are lost and the pool of competing stem cells is reduced. We tested whether this loss of stem cell competition would modify tumorigenesis. Reduction of Wnt ligand secretion accelerates fixation of Apc-deficient cells within the crypt leading to accelerated tumorigenesis. Therefore, ligand-based Wnt signalling influences the number of stem cells, fixation speed of Apc mutations and the speed and likelihood of adenoma formation.
Collapse
Affiliation(s)
- D J Huels
- CRUK Beatson Institute, Glasgow, G61 1BD, UK
| | - L Bruens
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and UMC Utrecht, 3584 CT, Utrecht, The Netherlands
- Molecular Pathology, Oncode Institute, The Netherlands Cancer Institute, 1066CX, Amsterdam, The Netherlands
- Center for Molecular Medicine, Oncode Institute, University Medical Center Utrecht, 3584 CG, Utrecht, The Netherlands
| | - M C Hodder
- CRUK Beatson Institute, Glasgow, G61 1BD, UK
| | - P Cammareri
- CRUK Beatson Institute, Glasgow, G61 1BD, UK
| | | | - R A Ridgway
- CRUK Beatson Institute, Glasgow, G61 1BD, UK
| | - D M Gay
- CRUK Beatson Institute, Glasgow, G61 1BD, UK
| | | | - W J Faller
- CRUK Beatson Institute, Glasgow, G61 1BD, UK
| | - C Nixon
- CRUK Beatson Institute, Glasgow, G61 1BD, UK
| | - L B Zeiger
- CRUK Beatson Institute, Glasgow, G61 1BD, UK
| | - M E McLaughlin
- Oncology Translational Research, Novartis Institutes for Biomedical Research, Cambridge, MA, 02139, USA
| | - E Morrissey
- MRC Weatherall Institute of Molecular Medicine University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DS, UK
| | - D J Winton
- CRUK Cambridge Institute, Cambridge, CB2 0RE, UK
| | - H J Snippert
- Center for Molecular Medicine, Oncode Institute, University Medical Center Utrecht, 3584 CG, Utrecht, The Netherlands
| | - J van Rheenen
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and UMC Utrecht, 3584 CT, Utrecht, The Netherlands
- Molecular Pathology, Oncode Institute, The Netherlands Cancer Institute, 1066CX, Amsterdam, The Netherlands
| | - O J Sansom
- CRUK Beatson Institute, Glasgow, G61 1BD, UK.
- Institute of Cancer Sciences (ICS), University of Glasgow, Glasgow, G12 8QQ, UK.
| |
Collapse
|
4
|
Lloyd-Lewis B, Davis FM, Harris OB, Hitchcock JR, Lourenco FC, Pasche M, Watson CJ. Imaging the mammary gland and mammary tumours in 3D: optical tissue clearing and immunofluorescence methods. Breast Cancer Res 2016; 18:127. [PMID: 27964754 PMCID: PMC5155399 DOI: 10.1186/s13058-016-0754-9] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 08/18/2016] [Indexed: 01/24/2023] Open
Abstract
Background High-resolution 3D imaging of intact tissue facilitates cellular and subcellular analyses of complex structures within their native environment. However, difficulties associated with immunolabelling and imaging fluorescent proteins deep within whole organs have restricted their applications to thin sections or processed tissue preparations, precluding comprehensive and rapid 3D visualisation. Several tissue clearing methods have been established to circumvent issues associated with depth of imaging in opaque specimens. The application of these techniques to study the elaborate architecture of the mouse mammary gland has yet to be investigated. Methods Multiple tissue clearing methods were applied to intact virgin and lactating mammary glands, namely 3D imaging of solvent-cleared organs, see deep brain (seeDB), clear unobstructed brain imaging cocktails (CUBIC) and passive clarity technique. Using confocal, two-photon and light sheet microscopy, their compatibility with whole-mount immunofluorescent labelling and 3D imaging of mammary tissue was examined. In addition, their suitability for the analysis of mouse mammary tumours was also assessed. Results Varying degrees of optical transparency, tissue preservation and fluorescent signal conservation were observed between the different clearing methods. SeeDB and CUBIC protocols were considered superior for volumetric fluorescence imaging and whole-mount histochemical staining, respectively. Techniques were compatible with 3D imaging on a variety of platforms, enabling visualisation of mammary ductal and lobulo-alveolar structures at vastly improved depths in cleared tissue. Conclusions The utility of whole-organ tissue clearing protocols was assessed in the mouse mammary gland. Most methods utilised affordable and widely available reagents, and were compatible with standard confocal microscopy. These techniques enable high-resolution, 3D imaging and phenotyping of mammary cells and tumours in situ, and will significantly enhance our understanding of both normal and pathological mammary gland development. Electronic supplementary material The online version of this article (doi:10.1186/s13058-016-0754-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Bethan Lloyd-Lewis
- Department of Pathology, University of Cambridge, Cambridge, CB2 1QP, UK.
| | - Felicity M Davis
- Department of Pathology, University of Cambridge, Cambridge, CB2 1QP, UK. .,School of Pharmacy, The University of Queensland, Brisbane, 4072, Australia.
| | - Olivia B Harris
- Department of Pathology, University of Cambridge, Cambridge, CB2 1QP, UK.,Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge, CB2 1QR, UK
| | | | - Filipe C Lourenco
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Cambridge, CB2 0RE, UK
| | - Mathias Pasche
- Medical Research Council Laboratory for Molecular Biology, Cambridge, CB2 0QH, UK
| | - Christine J Watson
- Department of Pathology, University of Cambridge, Cambridge, CB2 1QP, UK. .,Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge, CB2 1QR, UK.
| |
Collapse
|
5
|
Davis FM, Lloyd-Lewis B, Harris OB, Kozar S, Winton DJ, Muresan L, Watson CJ. Single-cell lineage tracing in the mammary gland reveals stochastic clonal dispersion of stem/progenitor cell progeny. Nat Commun 2016; 7:13053. [PMID: 27779190 PMCID: PMC5093309 DOI: 10.1038/ncomms13053] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 08/30/2016] [Indexed: 11/09/2022] Open
Abstract
The mammary gland undergoes cycles of growth and regeneration throughout reproductive life, a process that requires mammary stem cells (MaSCs). Whilst recent genetic fate-mapping studies using lineage-specific promoters have provided valuable insights into the mammary epithelial hierarchy, the true differentiation potential of adult MaSCs remains unclear. To address this, herein we utilize a stochastic genetic-labelling strategy to indelibly mark a single cell and its progeny in situ, combined with tissue clearing and 3D imaging. Using this approach, clones arising from a single parent cell could be visualized in their entirety. We reveal that clonal progeny contribute exclusively to either luminal or basal lineages and are distributed sporadically to branching ducts or alveoli. Quantitative analyses suggest that pools of unipotent stem/progenitor cells contribute to adult mammary gland development. Our results highlight the utility of tracing a single cell and reveal that progeny of a single proliferative MaSC/progenitor are dispersed throughout the epithelium.
Collapse
Affiliation(s)
- Felicity M. Davis
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
- School of Pharmacy, The University of Queensland, Brisbane 4072, Australia
| | | | - Olivia B. Harris
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
- WellcomeTrust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 1QR, UK
| | - Sarah Kozar
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Cambridge CB2 0RE, UK
| | - Douglas J. Winton
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Cambridge CB2 0RE, UK
| | - Leila Muresan
- Cambridge Advanced Imaging Centre, University of Cambridge, Cambridge CB2 1QP, UK
| | - Christine J. Watson
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
- WellcomeTrust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 1QR, UK
| |
Collapse
|
6
|
Wright DM, Buenger DE, Abashev TM, Lindeman RP, Ding J, Sandell LL. Retinoic acid regulates embryonic development of mammalian submandibular salivary glands. Dev Biol 2015; 407:57-67. [PMID: 26278034 DOI: 10.1016/j.ydbio.2015.08.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 08/03/2015] [Accepted: 08/11/2015] [Indexed: 01/09/2023]
Abstract
Organogenesis is orchestrated by cell and tissue interactions mediated by molecular signals. Identification of relevant signals, and the tissues that generate and receive them, are important goals of developmental research. Here, we demonstrate that Retinoic Acid (RA) is a critical signaling molecule important for morphogenesis of mammalian submandibular salivary glands (SMG). By examining late stage RA deficient embryos of Rdh10 mutant mice we show that SMG development requires RA in a dose-dependent manner. Additionally, we find that active RA signaling occurs in SMG tissues, arising earlier than any other known marker of SMG development and persisting throughout gland morphogenesis. At the initial bud stage of development, we find RA production occurs in SMG mesenchyme, while RA signaling occurs in epithelium. We also demonstrate active RA signaling occurs in glands cultured ex vivo, and treatment with an inhibitor of RA signaling blocks growth and branching. Together these data identify RA signaling as a direct regulator of SMG organogenesis.
Collapse
Affiliation(s)
- Diana M Wright
- University of Louisville School of Dentistry, Department of Molecular, Cellular and Craniofacial Biology, Louisville, KY 40201, USA
| | - Deanna E Buenger
- University of Louisville School of Dentistry, Department of Molecular, Cellular and Craniofacial Biology, Louisville, KY 40201, USA
| | - Timur M Abashev
- University of Louisville School of Dentistry, Department of Molecular, Cellular and Craniofacial Biology, Louisville, KY 40201, USA
| | - Robert P Lindeman
- University of Louisville School of Dentistry, Department of Molecular, Cellular and Craniofacial Biology, Louisville, KY 40201, USA
| | - Jixiang Ding
- University of Louisville School of Dentistry, Department of Molecular, Cellular and Craniofacial Biology, Louisville, KY 40201, USA
| | - Lisa L Sandell
- University of Louisville School of Dentistry, Department of Molecular, Cellular and Craniofacial Biology, Louisville, KY 40201, USA.
| |
Collapse
|
7
|
Breunig JJ, Levy R, Antonuk CD, Molina J, Dutra-Clarke M, Park H, Akhtar AA, Kim GB, Hu X, Bannykh SI, Verhaak RGW, Danielpour M. Ets Factors Regulate Neural Stem Cell Depletion and Gliogenesis in Ras Pathway Glioma. Cell Rep 2015; 12:258-71. [PMID: 26146073 DOI: 10.1016/j.celrep.2015.06.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 04/27/2015] [Accepted: 06/02/2015] [Indexed: 01/08/2023] Open
Abstract
As the list of putative driver mutations in glioma grows, we are just beginning to elucidate the effects of dysregulated developmental signaling pathways on the transformation of neural cells. We have employed a postnatal, mosaic, autochthonous glioma model that captures the first hours and days of gliomagenesis in more resolution than conventional genetically engineered mouse models of cancer. We provide evidence that disruption of the Nf1-Ras pathway in the ventricular zone at multiple signaling nodes uniformly results in rapid neural stem cell depletion, progenitor hyperproliferation, and gliogenic lineage restriction. Abolishing Ets subfamily activity, which is upregulated downstream of Ras, rescues these phenotypes and blocks glioma initiation. Thus, the Nf1-Ras-Ets axis might be one of the select molecular pathways that are perturbed for initiation and maintenance in glioma.
Collapse
Affiliation(s)
- Joshua J Breunig
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.
| | - Rachelle Levy
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - C Danielle Antonuk
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Jessica Molina
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Marina Dutra-Clarke
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Hannah Park
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Aslam Abbasi Akhtar
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Gi Bum Kim
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Xin Hu
- Department of Genomic Medicine, Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Serguei I Bannykh
- Department of Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Roel G W Verhaak
- Department of Genomic Medicine, Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Moise Danielpour
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| |
Collapse
|
8
|
Jay FF, Schneider MR. A reporter mouse line with doxycyclin-inducible expression of β-glucosidase. Histochem Cell Biol 2014; 142:721-4. [PMID: 25091595 DOI: 10.1007/s00418-014-1255-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/19/2014] [Indexed: 02/01/2023]
Abstract
Mouse lines allowing the inducible expression of transgenes became essential tools for studying gene function and for developing accurate animal models for human diseases. A key component of this tool is the availability of "reporter" lines, mice expressing transgenes encoding easily detectable enzymes or other proteins normally not associated with eukaryotic tissues. Such lines may be suitable for a number of applications, including lineage tracing, label-retaining experiments, and the identification and monitoring of regulatory elements important for tissue-specific gene expression. However, only a limited number of reporter lines suitable for inducible expression systems are available. Here, we employed pronuclear DNA microinjection to generate a new reporter mouse line that allows the inducible expression of β-glucosidase, a recently reported stable and easily detectable protein, upon administration of doxycyclin to the drinking water. This novel line was established in the widely used inbreed background C57BL/6, and the transgene is transmitted between generations in a Mendelian fashion. When crossed to a K14-rtTA mouse line, activation of β-glucosidase expression in the epidermal basal layer is easily detected in double-transgenic animals receiving doxycyclin, while no expression is seen in double-transgenic mice without doxycyclin treatment or in animals carrying only one transgene. We anticipate that this new mouse line will become a valuable tool for a number of applications in vivo, including label-retaining experiments and testing the appropriate regulation of rtTA cassettes under different promoters in novel transgenic mouse lines.
Collapse
Affiliation(s)
- Freya F Jay
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center, LMU Munich, Feodor-Lynen-Str. 25, 81377, Munich, Germany
| | | |
Collapse
|
9
|
Kozar S, Morrissey E, Nicholson AM, van der Heijden M, Zecchini HI, Kemp R, Tavaré S, Vermeulen L, Winton DJ. Continuous clonal labeling reveals small numbers of functional stem cells in intestinal crypts and adenomas. Cell Stem Cell 2013; 13:626-33. [PMID: 24035355 DOI: 10.1016/j.stem.2013.08.001] [Citation(s) in RCA: 162] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 07/12/2013] [Accepted: 08/07/2013] [Indexed: 12/21/2022]
Abstract
Lineage-tracing approaches, widely used to characterize stem cell populations, rely on the specificity and stability of individual markers for accurate results. We present a method in which genetic labeling in the intestinal epithelium is acquired as a mutation-induced clonal mark during DNA replication. By determining the rate of mutation in vivo and combining this data with the known neutral-drift dynamics that describe intestinal stem cell replacement, we quantify the number of functional stem cells in crypts and adenomas. Contrary to previous reports, we find that significantly lower numbers of "working" stem cells are present in the intestinal epithelium (five to seven per crypt) and in adenomas (nine per gland), and that those stem cells are also replaced at a significantly lower rate. These findings suggest that the bulk of tumor stem cell divisions serve only to replace stem cell loss, with rare clonal victors driving gland repopulation and tumor growth.
Collapse
Affiliation(s)
- Sarah Kozar
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Robinson Way, Cambridge CB2 0RE, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Buczacki SJA, Zecchini HI, Nicholson AM, Russell R, Vermeulen L, Kemp R, Winton DJ. Intestinal label-retaining cells are secretory precursors expressing Lgr5. Nature 2013; 495:65-9. [PMID: 23446353 DOI: 10.1038/nature11965] [Citation(s) in RCA: 568] [Impact Index Per Article: 51.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 01/30/2013] [Indexed: 12/24/2022]
Abstract
The rapid cell turnover of the intestinal epithelium is achieved from small numbers of stem cells located in the base of glandular crypts. These stem cells have been variously described as rapidly cycling or quiescent. A functional arrangement of stem cells that reconciles both of these behaviours has so far been difficult to obtain. Alternative explanations for quiescent cells have been that they act as a parallel or reserve population that replace rapidly cycling stem cells periodically or after injury; their exact nature remains unknown. Here we show mouse intestinal quiescent cells to be precursors that are committed to mature into differentiated secretory cells of the Paneth and enteroendocrine lineage. However, crucially we find that after intestinal injury they are capable of extensive proliferation and can give rise to clones comprising the main epithelial cell types. Thus, quiescent cells can be recalled to the stem-cell state. These findings establish quiescent cells as an effective clonogenic reserve and provide a motivation for investigating their role in pathologies such as colorectal cancers and intestinal inflammation.
Collapse
Affiliation(s)
- Simon J A Buczacki
- Cancer Research UK Cambridge Research Institute, Li Ka Shing Centre, Robinson Way, Cambridge CB2 0RE, UK
| | | | | | | | | | | | | |
Collapse
|
11
|
Delta1 expression, cell cycle exit, and commitment to a specific secretory fate coincide within a few hours in the mouse intestinal stem cell system. PLoS One 2011; 6:e24484. [PMID: 21915337 PMCID: PMC3168508 DOI: 10.1371/journal.pone.0024484] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Accepted: 08/11/2011] [Indexed: 12/11/2022] Open
Abstract
The stem cells of the small intestine are multipotent: they give rise, via transit-amplifying cell divisions, to large numbers of columnar absorptive cells mixed with much smaller numbers of three different classes of secretory cells - mucus-secreting goblet cells, hormone-secreting enteroendocrine cells, and bactericide-secreting Paneth cells. Notch signaling is known to control commitment to a secretory fate, but why are the secretory cells such a small fraction of the population, and how does the diversity of secretory cell types arise? Using the mouse as our model organism, we find that secretory cells, and only secretory cells, pass through a phase of strong expression of the Notch ligand Delta1 (Dll1). Onset of this Dll1 expression coincides with a block to further cell division and is followed in much less than a cell cycle time by expression of Neurog3 – a marker of enteroendocrine fate – or Gfi1 – a marker of goblet or Paneth cell fate. By conditional knock-out of Dll1, we confirm that Delta-Notch signaling controls secretory commitment through lateral inhibition. We infer that cells stop dividing as they become committed to a secretory fate, while their neighbors continue dividing, explaining the final excess of absorptive over secretory cells. Our data rule out schemes in which cells first become committed to be secretory, and then diversify through subsequent cell divisions. A simple mathematical model shows how, instead, Notch signaling may simultaneously govern the commitment to be secretory and the choice between alternative modes of secretory differentiation.
Collapse
|