News Article | October 28, 2015
No statistical methods were used to predetermine sample size. YapΔ/Δ and TazΔ/Δ mice were generated by crossing Yap or Taz floxed mice30 with the villin-cre line (Jackson Laboratory), the villin-creERT2 line (S. Robine, Institut Curie-CNRS) or the Lgr5-creERT line (Jackson Laboratory). The Rosa26-lox-STOP-lox-rtta-IRES-EGFP and Rosa26 lacZ mouse lines were obtained from Jackson Laboratory. The YapTg transgenic line described in this study was generated by introducing a HA-tagged wild-type Yap cDNA downstream of 7 Tet-repressor elements in the pTRE2 vector (J. Whitsett, Cincinnati Children’s Hospital Medical Center). The transgenic Yap construct was linearized and microinjected in ICR embryos. As shown in Extended Data Fig. 3a, activation of Cre deletes a neo cassette and allows for expression of the rtTA gene. In the presence of doxycycline the rtTA activates transcription of HA-Yap. Apc floxed mice were obtained from O. Sansom (Beatson Institute). Lats1 and Lats2 floxed alleles were obtained from R. Johnson (MD Anderson Cancer Center) and crossed with villin-creERT2 mice to obtain Lats1Δ/Δ;Lats2Δ/Δ mice. To measure polyp formation, YapΔ/Δ mice were backcrossed to a Bl/6 background for 4 generations before crossing to ApcMin/+ mice. Polyps from Yap+/+ (Yap+/+;villin-cre;ApcMin/+), Yap+/Δ (Yapfl/+;villin-cre;ApcMin/+) and YapΔ/Δ (Yapfl/fl;villin-cre;ApcMin/+) mice were counted 16 weeks after birth or when animals appeared moribund. Survival of ApcMin mice was measured by the number of days before mice were euthanized due to poor health. In vivo assays comparing control and Yap mutant animals were performed between age- and sex-matched pairs. No method of randomization was followed and no animals were excluded in this study. The investigators were not blinded to allocation during experiments and outcome assessment. Inducible Cre-mediated deletion of genes was performed by intraperitoneal injections of >5-week-old mice with 200 μl tamoxifen in corn oil at 10 mg ml−1. To create mosaic expression of Yap, Yapfl/fl;villin-creERT2 mice were induced with a single injection of 200 μl of tamoxifen at a suboptimal dose typically between 0.5 and 2.0 mg ml−1. For in vivo regeneration assays, mice were given a single dose of 10 or 12 Gy using a GammaCell 40 irradiator. Animals were maintained and handled under procedures approved by the Canadian Council on Animal Care. The immunohistochemistry stainings and standard colorimetric in situ hybridization were carried out according to methods described elsewhere31. Staining experiments were repeated on independent tissue sections prepared from separate mice as indicated by n values in figure legends. The following primary antibodies were used for immunostaining: rat anti-Ki67 (Dako, Cat. no. M7249, 1:1,000), rabbit anti-Yap/Taz (Cell Signaling, Cat. no. 8418, 1:100), rabbit anti-Yap (Cell Signaling, Cat. no. 14074, 1:300), mouse anti-Yap (Santa Cruz, Cat. no. sc-101199, 1:100), rabbit anti-Lef (Cell Signaling, Cat. no. 2230, 1:300), phosphor-Egfr (Tyr1092) (Abcam, Cat. no. ab40815, 1:300), anti-cleaved caspase-3 (Cell Signaling, Cat. no. 9664, 1:300) and anti-lysozyme (Dako, Cat. no. A0099, 1:1,000). Detection of primary antibodies was achieved using the Dako Envision plus system. Multi-colour fluorescence in situ hybridization with tyramide signal amplification (TSA) was done essentially as described elsewhere32, 33, 34. In brief, RNA probes from hybridized sections were detected using appropriate hapten-specific HRP-conjugated antibodies (anti-digoxigenin-HRP (Roche, Cat. no. 11207733910, 1:500), anti-dinitrophenyl-HRP (PerkinElmer, Cat. no. NEL747A001KT, 1:300), and anti-fluorescein-HRP (Life Technologies, A21253, 1:500)). After overnight incubation with antibodies at 4°C (or 2 h at room temperature for anti-fluorescein-HRP detection of cryptin1) sections were washed in PBS, and rinsed twice in 100 mM borate pH 8.5 plus 0.1% BSA. TSA reaction was performed by applying 300 μl per slide of the following mixture: 100 mM borate pH 8.5, 2% dextran sulfate, 0.1% Tween-20 and 0.003% H O , 450 μg ml−1 4-iodophenol: 1:250 Tyramide product (that is, DyLight633-tyramide, Dylight488-tyramide, Dylight 555-tyramide). The TSA reaction was allowed to proceed for 20 min and then terminated by washing slides in 100 mM glycine pH 2.0 for 15 min. Sections were washed further in PBS for the next round of detection. To synthesize tyramide products, the following succinimidyl esters were used for conjugation with tyramine: DyLight 633 NHS-Ester (Thermo Scientific Cat#46414), DyLight 550 NHS-Ester (Thermo Scientific Cat#62262), DyLight 488 NHS-Ester (Thermo Scientific Cat. no. 46402). The synthesis reaction was carried out as described previously32. The following in situ hybridization probes were obtained from the collection of MGC clones at the Lunenfeld Tanenbaum Research Institute: TweakR (BC025860), Ly6c1 (BC092082), Edn1 (BC029547), Areg (BC009138), Ereg (BC027838), Il1rn (BC042532), Il33 (BC003847), Msln (BC023753) and Cyr61 (BC066019). The Olfm4 and cryptdin1 probes were a gift from H. Clevers (Hubrecht Institute). Before fixing organoids, 10 μM Edu was added to the culture media for 1 h. Then organoids were fixed in 10% buffered formalin for 30 min, permeabilized in 0.5% Triton for 20 min and blocked in 2% BSA. Incorporated Edu was detected using the ClickIt EDU Imaging kit (Invitrogen) according to the manufacturer’s instructions. The primary antibodies used for immunostaining were mouse anti-Yap (Santa Cruz, Cat # sc-101199, 1:100), mouse anti-HA (Sigma-Aldrich, Cat. no. H9658, 1:1,000), and chicken anti-β-gal (Abcam, Cat. no. ab9361, 1:300). The secondary antibodies used in immunostaining were: CF555-donkey anti-mouse (Biotium, Cat. no. 20037, 1:400) and CF647 donkey anti-rabbit (Biotium, Cat. no. 20047, 1:400). Organoids were counterstained with 4′,6-diamidino-2-phenylindole dihydrochloride (DAPI) (Sigma-Aldrich) before mounting onto slides for visualization. Images were acquired using a 20×/NA oil immersion objective lens (HCX PL APO, Leica), an EM-CCD camera (ImagEM, Hamamatsu) on an inverted microscope (DMIRE2, Leica) with a spinning disk confocal scanner (CSU10, Yokogawa) and Volocity. De novo crypts were scored as any protrusions, typically containing Paneth cells, budding from the initial sphere formed after seeding isolated crypts. Crypts were counted from bright-field images using Image J. At least four independent cultures derived from four different mice per genotype were used for quantification. Survival of crypts in Fig. 1 was determined by Ki67 staining of cross-sections of proximal portions of the small intestine at 3 days post-irradiation (10 Gy or 12 Gy). Values in Fig. 1b represent average number of fully labelled Ki67+ crypts per intestinal circumference based on counts from at least two sections per mouse and assays were repeated in 6 independent mice per genotype for both 10 Gy and 12 Gy treatments. The percentage of surviving Yap-positive versus negative Lgr5+ ISCs in Fig. 1d was performed by counting 587 β-gal+ crypts from a total of 7 untreated YapΔLgr5-cre mice and 394 β-gal+ crypts from a total of 9 irradiated YapΔLgr5-cre mice. In Yap;ApcΔLgr5-cre mice tumour initiating cells were visualized by staining for the Wnt target gene, Lef. As shown in Extended Data Fig. 10b, Lef is undetected in wild-type crypts and highly upregulated in Apc-null cells and thus serves as a robust marker of Apc deletion31. The percentage of Paneth cells in Lef+ foci (Fig. 4a) was assessed by preparing consecutive sections stained for Lyz, Lef and Yap, respectively. Lysozyme-positive Paneth cells from a total of 207 Yap wild-type and 201 Yap mutant Lef+ foci were counted from 5 Yap;ApcΔLgr5-cre mice (10–16 days after tamoxifen injection) using Image J and the percentage of total cells within the boundaries of a given Lef+ lesion was calculated. Relative activation of Egfr was quantified in consecutive sections from 5 Yap;ApcΔLgr5-cre mice stained for Lef, Yap and phospho-Egfr. For assessing Phospho-Egfr, staining intensity in Lef+ foci was assessed in a blinded fashion. For this, consecutive sections stained for Yap were masked from the observer scoring phospho-Egfr staining intensity. Lef+ foci were scored as ‘+’ if phospho-Egfr expression was elevated compared to wild-type adjacent crypts at comparable levels within the crypt–villus axis (see Extended Data Fig. 10f, panels xi and xii). Lef+ foci were scored as ‘++’ if staining intensity was very strong even relative to the stem cell compartment in normal crypts and/or displayed prominent apical staining (see Yap-positive foci in Fig. 4c, panel iv, and Extended Data Fig. 10f, panels v and vi). Lef+ foci were scored as ‘–’ if staining intensity was undetected or unchanged relative to adjacent wild-type crypts (see Yap mutant foci in Fig. 4c and Extended Data Fig. 10f). In Extended Data Fig. 1, caspase 3 and BrdU positive crypt cells were counted from at least six sections per mouse in 4 independent mice per genotype and expressed as a percentage of total crypt cells. All data are presented as average values with s.e.m. Mann–Whitney (two-tailed) U-test was used to determine statistical significance. Calculations were performed using GraphPad Prism 5 software. RNA was isolated from organoids cultured for 24 h after seeding in Matrigel. RNA samples were pooled from at least three organoid cultures derived from at least three independent mice per genotype (Yapfl/+;villin-cre, Yapfl/fl;villin-cre and YapTg). Quality of RNA was verified by running samples on a Bioanalyzer. High-throughput sequencing was performed using the Illumina HiSeq 2000 at the Lunenfeld Tanenbaum Research Institute (LTRI) sequencing facility. Raw sequencing reads in Fastq formats were mapped onto mouse genome (mm9) using Tophat 1.4.1 and the RPKMs (reads per kilobase of exon model per million mapped reads) were calculated using a customized script. RNA-seq data are presented in Supplementary Table 1. Combined fold change presented in Extended Data Fig. 3d and Supplementary Table 1 was calculated using the following formula: combination fold change = log [(YapΔ/Δ/Yap+/Δ)/(Dox+/Dox−)]. R, Cluster 3.0 and Java TreeView were used for data visualization. Gut organoids were cultured according to a previously described protocol established by Sato and Clevers7. Briefly, crypts were harvested by incubating opened small intestines in PBS containing 2 mM EDTA. The epithelium was released by vigorous shaking and crypts separated using a 70 μm cell strainer. Crypts were seeded in growth factor reduced Matrigel (BD Biosciences) and grown in Advanced DMEM/F12 (Invitrogen) supplemented with 2 mM GlutaMax (Invitrogen), 100 U ml−1 Penicillin/100 μg ml−1 Streptomycin (Invitrogen), N2 Supplement (Invitrogen), B-27 Supplement (Invitrogen Cat), mouse recombinant Egf (R&D Systems), 100 ng ml−1 mouse recombinant Noggin (Peprotech), 150 ng ml−1 human Rsp1 (R&D Systems). Apc-deficient organoids were harvested from Yapfl/+;Apcfl/fl;villin-creERT, Yapfl/fl;Apcfl/fl;villin-creERT or YapTg;Apcfl/fl;villin-creERT mice injected with tamoxifen and seeded 48 h later in basal growth medium without Egf, Rsp1 or Noggin. To induce Yap expression in YapTg organoids, 1.5 μg ml−1 doxycycline was added to the culture medium on day 0. Egf (R&D Systems, Cat. no. AF2028), Areg (R&D Systems, Cat. no. AF989) and Ereg (R&D Systems, Cat. no. 1068-EP-050) were added to the culture medium at a final concentration of 0.5 μg ml−1. The following inhibitors were used: PD153053 (0.5 μM, Tocris Bioscience), U0126 (10 μM, Merck Millipore). To examine pErk1/2 levels, organoids were harvested at day 2 in cold PBS containing 5 mM EDTA, 1 mM NaVO , 1.5 mM NaF and protease inhibitors. Organoids were incubated at 4°C for 30 min to dissolve Matrigel and then lysed in TNTE buffer (50 mM Tris/HCl pH 7.6, 150 mM NaCl, 0.5% Triton X-100, 1 mM EDTA) containing standard protease and phosphatase inhibitors. Protein concentrations were measured and samples were subjected to SDS–PAGE. Total RNA was extracted by removing culture medium and directly lysing organoids in wells using RTL buffer of the Rneasy Mini Kit (Qiagen). RNA was purified using columns and genomic DNA was removed by treatment with RNase-Free DNase (Qiagen).
Hagerling R.,Max Planck Institute for Molecular Biomedicine |
Pollmann C.,Max Planck Institute for Molecular Biomedicine |
Andreas M.,Max Planck Institute for Molecular Biomedicine |
Schmidt C.,Max Planck Institute for Molecular Biomedicine |
And 7 more authors.
EMBO Journal | Year: 2013
During mammalian development, a subpopulation of endothelial cells in the cardinal vein (CV) expresses lymphatic-specific genes and subsequently develops into the first lymphatic structures, collectively termed as lymph sacs. Budding, sprouting and ballooning of lymphatic endothelial cells (LECs) have been proposed to underlie the emergence of LECs from the CV, but the exact mechanisms of lymph vessel formation remain poorly understood. Applying selective plane illumination-based ultramicroscopy to entire wholemount-immunostained mouse embryos, we visualized the complete developing vascular system with cellular resolution. Here, we report emergence of the earliest detectable LECs as strings of loosely connected cells between the CV and superficial venous plexus. Subsequent aggregation of LECs resulted in formation of two distinct, previously unidentified lymphatic structures, the dorsal peripheral longitudinal lymphatic vessel (PLLV) and the ventral primordial thoracic duct (pTD), which at later stages formed a direct contact with the CV. Providing new insights into their function, we found vascular endothelial growth factor C (VEGF-C) and the matrix component CCBE1 indispensable for LEC budding and migration. Altogether, we present a significantly more detailed view and novel model of early lymphatic development. © 2013 European Molecular Biology Organization.
Hubrecht Institute and Konicklijke Nederlandse Akademie Van Wetenschappen | Date: 2010-05-10
The invention relates to the fields of biochemistry, pharmacy and oncology. The invention particularly relates to the use of novel stem cell markers for the isolation of stem cells. The invention further relates to the obtained stem cells and their use in for example research or treatment, for example, for the preparation of a medicament for the treatment of damaged or diseased tissue. In one of the embodiments, the invention provides a method for obtaining (or isolating) stem cells comprising optionally preparing a cell suspension from a tissue or organ sample, contacting said cell suspension with an Lgr 6 or 5 binding compound, identify the cells bound to said binding compound, and optionally isolating the stem cells from said binding compound. The invention further relates to means suitable for cancer treatment and even more specific for the treatment of cancer by eradicating cancer stem cells.
Fennema E.,University of Twente |
Rivron N.,University of Twente |
Rivron N.,Hubrecht Institute |
Rouwkema J.,University of Twente |
And 2 more authors.
Trends in Biotechnology | Year: 2013
3D cell culture methods confer a high degree of clinical and biological relevance to in vitro models. This is specifically the case with the spheroid culture, where a small aggregate of cells grows free of foreign materials. In spheroid cultures, cells secrete the extracellular matrix (ECM) in which they reside, and they can interact with cells from their original microenvironment. The value of spheroid cultures is increasing quickly due to novel microfabricated platforms amenable to high-throughput screening (HTS) and advances in cell culture. Here, we review new possibilities that combine the strengths of spheroid culture with new microenvironment fabrication methods that allow for the creation of large numbers of highly reproducible, complex tissues. © 2013.
Barker N.,Hubrecht Institute |
Clevers H.,Hubrecht Institute
Gastroenterology | Year: 2010
Molecular markers are used to characterize and track adult stem cells. Colon cancer research has led to the identification of 2 related receptors, leucine-rich repeat-containing, G-protein-coupled receptors (Lgr)5 and Lgr6, that are expressed by small populations of cells in a variety of adult organs. Genetic mouse models have allowed the visualization, isolation, and genetic marking of Lgr5+ve and Lgr6+ve cells and provided evidence that they are stem cells. The Lgr5+ve cells were found to occupy locations not commonly associated with stem cells in the stomach, small intestine, colon, and hair follicles. A multipotent population of skin stem cells express Lgr6. Single Lgr5+ve stem cells from the small intestine and the stomach can be cultured into long-lived organoids. Further studies of these markers might reveal adult stem cell populations in additional tissues. Identification of the ligands for Lgr5 and 6 will help elucidate stem cell functions and modes of intracellular signaling. © 2010 AGA Institute.
Sato T.,Keio University |
Sato T.,Hubrecht Institute |
Clevers H.,Hubrecht Institute
Methods in Molecular Biology | Year: 2013
The intestinal epithelium is the most rapidly self-renewing tissue in adult mammals. We have recently shown that Lgr5 (Leucine-rich repeat-containing G protein-coupled receptor) is expressed in intestinal stem cells by an in vivo genetic lineage tracing strategy. In the past, extensive efforts have been made to establish primary small intestinal culture systems. However, no defined, reproducible and robust culture system had been developed. To establish such a system, we screened for optimal growth factor combinations based on genetic evidence of self-renewal regulation, differentiation, and carcinogenesis of intestinal stem cells. Here, we describe methods that we have established for the isolation and culture of primary small intestinal epithelial stem cells. In this culture system, isolated crypts form organoid structures with a histological hierarchy recapitulating in vivo small intestinal epithelium. Single isolated Lgr5+ intestinal stem cells also form these organoid structures, in which stem cells are maintained by self-renewal and give rise to all lineages of the intestinal epithelium. This culture system is particularly useful for studying the regulation of intestinal stem cell self-renewal and differentiation. © 2013 Springer Science+Business Media, LLC.
Barker N.,Hubrecht Institute |
Barker N.,University Utrecht |
Bartfeld S.,Max Planck Institute for Infection Biology |
Clevers H.,Hubrecht Institute |
Clevers H.,University Utrecht
Cell Stem Cell | Year: 2010
The epithelial lining of the intestine, stomach, and skin is continuously exposed to environmental assault, imposing a requirement for regular self-renewal. Resident adult stem cell populations drive this renewal, and much effort has been invested in revealing their identity. Reliable adult stem cell biomarkers would accelerate our understanding of stem cell roles in tissue homeostasis and cancer. Membrane-expressed markers would also facilitate isolation of these adult stem cell populations for exploitation of their regenerative potential. Here, we review recent advances in adult stem cell biology, highlighting the promise and pitfalls of the candidate biomarkers of the various stem cell populations. © 2010 Elsevier Inc.
Van Impel A.,Hubrecht Institute |
Schulte-Merker S.,Hubrecht Institute
Advances in Anatomy Embryology and Cell Biology | Year: 2014
Zebrafish have been widely used to study vasculogenesis and angiogenesis, and the vascular system is one of the most intensively studied organ systems in teleosts. It is a little surprising, therefore, that the development of the zebrafish lymphatic network has only been investigated in any detail for less than a decade now. In those last few years, however, significant progress has been made. Due to favorable imaging possibilities within the early zebrafish embryo, we have a very good understanding of what cellular behavior accompanies the formation of the lymphatic system and which cells within the vasculature are destined to contribute to lymphatic vessels. The migration routes of future lymphatic endothelial cells have been monitored in great detail, and a number of transgenic lines have been developed that help to distinguish between arterial, venous, and lymphatic fates in vivo. Furthermore, both forward and reverse genetic tools have been systematically employed to unravel which genes are involved in the process. Not surprisingly, a number of known players were identified (such as vegfc and flt4), but work on zebrafish has also distinguished genes and proteins that had not previously been connected to lymphangiogenesis. Here, we will review these topics and also compare the equivalent stages of lymphatic development in zebrafish and mice. We will, in addition, highlight some of those studies in zebrafish that have helped to identify and to further characterize human disease conditions. © Springer-Verlag Wien 2014.
Welling M.,Hubrecht Institute |
Geijsen N.,Hubrecht Institute |
Geijsen N.,University Utrecht
Trends in Cell Biology | Year: 2013
Embryonic stem cells (ESCs) are pluripotent stem cells derived from the inner cell mass (ICM) of blastocyst embryos. Although first characterized over 30 years ago, the ontology of these cells remains elusive. Identifying the in vivo counterpart of murine ESCs will be essential for the derivation of stable ESC lines from other species. Several hypotheses exist concerning the ontology of murine ESCs. Recent data demonstrate that ESCs emerge from a subpopulation of ICM cells that transit through a Blimp1-positive state, suggesting that perhaps a germ cell developmental program underlies ESC derivation and maintenance. Alternatively, the common dependence of ESCs and diapause embryos on the cytokine LIF (leukemia inhibitory factor) has been thought to signify that murine ESCs employ a diapause-like program for their maintenance of pluripotency. Here we review different hypotheses regarding the nature of murine ESCs and discuss their implications for human pluripotent stem cell biology. © 2013 Elsevier Ltd.
Gommans W.M.,Hubrecht Institute |
Berezikov E.,Hubrecht Institute
Methods in Molecular Biology | Year: 2012
Our understanding of the importance of noncoding RNA molecules is steadily growing. One such important class of RNA molecules are microRNAs (miRNAs). These tiny RNAs fulfill important functions in cellular behavior by influencing the protein output levels of a high variety of genes through the regulation of target messenger RNAs. Moreover, miRNAs have been implicated in a wide range of diseases. In pathological conditions, the miRNA expression levels can be altered due to changes in the transcriptional or posttranscriptional regulation of miRNA expression. On the other side, mRNA molecules might be able to escape the regulation by miRNAs. In this review, we give an overview on how miRNA biogenesis can be altered in disease as well as how mRNAs can avoid the regulation by miRNAs. The interplay between these two processes defines the final protein output in a cell, and thus the normal or pathological cellular phenotype. © 2012 Springer Science+Business Media, LLC.