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1.
Nature ; 616(7958): 774-782, 2023 04.
Article in English | MEDLINE | ID: mdl-37076619

ABSTRACT

For unknow reasons, the melanocyte stem cell (McSC) system fails earlier than other adult stem cell populations1, which leads to hair greying in most humans and mice2,3. Current dogma states that McSCs are reserved in an undifferentiated state in the hair follicle niche, physically segregated from differentiated progeny that migrate away following cues of regenerative stimuli4-8. Here we show that most McSCs toggle between transit-amplifying and stem cell states for both self-renewal and generation of mature progeny, a mechanism fundamentally distinct from those of other self-renewing systems. Live imaging and single-cell RNA sequencing revealed that McSCs are mobile, translocating between hair follicle stem cell and transit-amplifying compartments where they reversibly enter distinct differentiation states governed by local microenvironmental cues (for example, WNT). Long-term lineage tracing demonstrated that the McSC system is maintained by reverted McSCs rather than by reserved stem cells inherently exempt from reversible changes. During ageing, there is accumulation of stranded McSCs that do not contribute to the regeneration of melanocyte progeny. These results identify a new model whereby dedifferentiation is integral to homeostatic stem cell maintenance and suggest that modulating McSC mobility may represent a new approach for the prevention of hair greying.


Subject(s)
Cell Dedifferentiation , Hair Follicle , Melanocytes , Stem Cell Niche , Stem Cells , Animals , Humans , Mice , Hair Follicle/cytology , Melanocytes/cytology , Stem Cells/cytology , Cellular Microenvironment , Cell Lineage , Aging , Homeostasis , Hair Color/physiology
2.
bioRxiv ; 2023 Mar 15.
Article in English | MEDLINE | ID: mdl-36993619

ABSTRACT

In most cell types, nuclear ß-catenin functions as prominent oncogenic driver and pairs with TCF7-family factors for transcriptional activation of MYC. Surprisingly, B-lymphoid malignancies not only lacked expression and activating lesions of ß-catenin but critically depended on GSK3ß for effective ß-catenin degradation. Our interactome studies in B-lymphoid tumors revealed that ß-catenin formed repressive complexes with lymphoid-specific Ikaros factors at the expense of TCF7. Instead of MYC-activation, ß-catenin was essential to enable Ikaros-mediated recruitment of nucleosome remodeling and deacetylation (NuRD) complexes for transcriptional repression of MYC. To leverage this previously unrecognized vulnerability of B-cell-specific repressive ß-catenin-Ikaros-complexes in refractory B-cell malignancies, we examined GSK3ß small molecule inhibitors to subvert ß-catenin degradation. Clinically approved GSK3ß-inhibitors that achieved favorable safety prof les at micromolar concentrations in clinical trials for neurological disorders and solid tumors were effective at low nanomolar concentrations in B-cell malignancies, induced massive accumulation of ß-catenin, repression of MYC and acute cell death. Preclinical in vivo treatment experiments in patient-derived xenografts validated small molecule GSK3ß-inhibitors for targeted engagement of lymphoid-specific ß-catenin-Ikaros complexes as a novel strategy to overcome conventional mechanisms of drug-resistance in refractory malignancies. HIGHLIGHTS: Unlike other cell lineages, B-cells express nuclear ß-catenin protein at low baseline levels and depend on GSK3ß for its degradation.In B-cells, ß-catenin forms unique complexes with lymphoid-specific Ikaros factors and is required for Ikaros-mediated tumor suppression and assembly of repressive NuRD complexes. CRISPR-based knockin mutation of a single Ikaros-binding motif in a lymphoid MYC superenhancer region reversed ß-catenin-dependent Myc repression and induction of cell death. The discovery of GSK3ß-dependent degradation of ß-catenin as unique B-lymphoid vulnerability provides a rationale to repurpose clinically approved GSK3ß-inhibitors for the treatment of refractory B-cell malignancies. GRAPHICAL ABSTRACT: Abundant nuclear ß-cateninß-catenin pairs with TCF7 factors for transcriptional activation of MYCB-cells rely on efficient degradation of ß-catenin by GSK3ßB-cell-specific expression of Ikaros factors Unique vulnerability in B-cell tumors: GSK3ß-inhibitors induce nuclear accumulation of ß-catenin.ß-catenin pairs with B-cell-specific Ikaros factors for transcriptional repression of MYC.

3.
Dev Cell ; 57(8): 1053-1067.e5, 2022 04 25.
Article in English | MEDLINE | ID: mdl-35421372

ABSTRACT

Organ formation requires integrating signals to coordinate proliferation, specify cell fates, and shape tissue. Tracing these events and signals remains a challenge, as intermediate states across many critical transitions are unresolvable over real time and space. Here, we designed a unique computational approach to decompose a non-linear differentiation process into key components to resolve the signals and cell behaviors that drive a rapid transition, using the hair follicle dermal condensate as a model. Combining scRNA sequencing with genetic perturbation, we reveal that proliferative Dkk1+ progenitors transiently amplify to become quiescent dermal condensate cells by the mere spatiotemporal patterning of Wnt/ß-catenin and SHH signaling gradients. Together, they deterministically coordinate a rapid transition from proliferation to quiescence, cell fate specification, and morphogenesis. Moreover, genetically repatterning these gradients reproduces these events autonomously in "slow motion" across more intermediates that resolve the process. This analysis unravels two morphogen gradients that intersect to coordinate events of organogenesis.


Subject(s)
Signal Transduction , Skin , Cell Differentiation , Hair Follicle , Hedgehog Proteins/genetics , Morphogenesis , Signal Transduction/genetics
5.
Nat Commun ; 13(1): 633, 2022 02 02.
Article in English | MEDLINE | ID: mdl-35110543

ABSTRACT

The choroid plexus secretes cerebrospinal fluid and is critical for the development and function of the brain. In the telencephalon, the choroid plexus epithelium arises from the Wnt- expressing cortical hem. Canonical Wnt signaling pathway molecules such as nuclear ß-CATENIN are expressed in the mouse and human embryonic choroid plexus epithelium indicating that this pathway is active. Point mutations in human ß-CATENIN are known to result in the constitutive activation of canonical Wnt signaling. In a mouse model that recapitulates this perturbation, we report a loss of choroid plexus epithelial identity and an apparent transformation of this tissue to a neuronal identity. Aspects of this phenomenon are recapitulated in human embryonic stem cell derived organoids. The choroid plexus is also disrupted when ß-Catenin is conditionally inactivated. Together, our results indicate that canonical Wnt signaling is required in a precise and regulated manner for normal choroid plexus development in the mammalian brain.


Subject(s)
Choroid Plexus/metabolism , Epithelium/metabolism , Wnt Proteins/metabolism , Wnt Signaling Pathway/physiology , Animals , Cell Differentiation , Cell Nucleus/metabolism , Choroid Plexus/pathology , Female , Humans , Male , Mice , Telencephalon/metabolism , Wnt Signaling Pathway/genetics , beta Catenin/genetics , beta Catenin/metabolism
6.
Cancer Lett ; 522: 129-141, 2021 12 01.
Article in English | MEDLINE | ID: mdl-34543685

ABSTRACT

Mutations of KRAS gene are found in various types of cancer, including colorectal cancer (CRC). Despite intense efforts, no pharmacological approaches are expected to be effective against KRAS-mutant cancers. Macropinocytosis is an evolutionarily conserved actin-dependent endocytic process that internalizes extracellular fluids into large vesicles called macropinosomes. Recent studies have revealed macropinocytosis's important role in metabolic adaptation to nutrient stress in cancer cells harboring KRAS mutations. Here we showed that KRAS-mutant CRC cells enhanced macropinocytosis for tumor growth under nutrient-depleted conditions. We also demonstrated that activation of Rac1 and phosphoinositide 3-kinase were involved in macropinocytosis of KRAS-mutant CRC cells. Furthermore, we found that macropinocytosis was closely correlated with asparagine metabolism. In KRAS-mutant CRC cells engineered with knockdown of asparagine synthetase, macropinocytosis was accelerated under glutamine-depleted condition, and albumin addition could restore the glutamine depletion-induced growth suppression by recovering the intracellular asparagine level. Finally, we discovered that the combination of macropinocytosis inhibition and asparagine depletion dramatically suppressed the tumor growth of KRAS-mutant CRC cells in vivo. These results indicate that dual blockade of macropinocytosis and asparagine bioavailability could be a novel therapeutic strategy for KRAS-mutant cancers.


Subject(s)
Aspartate-Ammonia Ligase/genetics , Colorectal Neoplasms/therapy , Pinocytosis/genetics , Proto-Oncogene Proteins p21(ras)/genetics , Asparagine/genetics , Asparagine/metabolism , Aspartate-Ammonia Ligase/antagonists & inhibitors , Cell Line, Tumor , Cell Proliferation/genetics , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/pathology , Gene Knockdown Techniques , Humans , Mutation/genetics , Phosphatidylinositol 3-Kinases/genetics , rac1 GTP-Binding Protein/genetics
7.
Commun Biol ; 4(1): 694, 2021 06 07.
Article in English | MEDLINE | ID: mdl-34099861

ABSTRACT

Tumor-infiltrating lymphocytes (TIL), which include tumor-specific T lymphocytes with frequency, are used for adoptive cell transfer therapy (ACT) in clinical practice. The optimization of TIL preparation has been investigated to reduce the senescence and increase the abundance of TIL, as both the quality and quantity of the transferred cells have great influence on the outcome of TIL-based ACT (TIL-ACT). Considering the effects of cell reprogramming on senescence, we expected that the anti-tumor effect could be enhanced by TIL regeneration. To confirm this hypothesis, we established tumor-specific TIL-derived iPS cells (TIL-iPSC) with human colorectal cancer specimens. T cells differentiated from TIL-iPSC (TIL-iPS-T) retained not only intrinsic T cell functions and tumor specificity, but also exhibited improved proliferation capacity and additional killing activity. Moreover, less differentiated profiles and prolonged persistency were seen in TIL-iPS-T compared with primary cells. Our findings imply that iPSC technology has great potential for TIL-ACT.


Subject(s)
Colorectal Neoplasms/therapy , Induced Pluripotent Stem Cells/immunology , Lymphocytes, Tumor-Infiltrating/immunology , T-Lymphocytes/immunology , Animals , Cell Line, Tumor , Cells, Cultured , Colorectal Neoplasms/immunology , Female , Humans , Immunotherapy , Induced Pluripotent Stem Cells/cytology , Lymphocyte Activation , Lymphocytes, Tumor-Infiltrating/cytology , Mice, Inbred NOD , Mice, SCID , T-Lymphocytes/cytology , T-Lymphocytes/transplantation
8.
Immunity ; 54(6): 1200-1218.e9, 2021 06 08.
Article in English | MEDLINE | ID: mdl-33951416

ABSTRACT

Tissue macrophages self-renew during homeostasis and produce inflammatory mediators upon microbial infection. We examined the relationship between proliferative and inflammatory properties of tissue macrophages by defining the impact of the Wnt/ß-catenin pathway, a central regulator of self-renewal, in alveolar macrophages (AMs). Activation of ß-catenin by Wnt ligand inhibited AM proliferation and stemness, but promoted inflammatory activity. In a murine influenza viral pneumonia model, ß-catenin-mediated AM inflammatory activity promoted acute host morbidity; in contrast, AM proliferation enabled repopulation of reparative AMs and tissue recovery following viral clearance. Mechanistically, Wnt treatment promoted ß-catenin-HIF-1α interaction and glycolysis-dependent inflammation while suppressing mitochondrial metabolism and thereby, AM proliferation. Differential HIF-1α activities distinguished proliferative and inflammatory AMs in vivo. This ß-catenin-HIF-1α axis was conserved in human AMs and enhanced HIF-1α expression associated with macrophage inflammation in COVID-19 patients. Thus, inflammatory and reparative activities of lung macrophages are regulated by ß-catenin-HIF-1α signaling, with implications for the treatment of severe respiratory diseases.


Subject(s)
COVID-19/immunology , COVID-19/virology , Cell Self Renewal/immunology , Host-Pathogen Interactions/immunology , Macrophages/immunology , SARS-CoV-2/immunology , Biomarkers , COVID-19/metabolism , Cytokines/metabolism , Disease Susceptibility/immunology , Humans , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Inflammation Mediators/metabolism , Macrophages/cytology , Macrophages/metabolism , Macrophages, Alveolar/immunology , Macrophages, Alveolar/metabolism , Signal Transduction
9.
Proc Natl Acad Sci U S A ; 117(35): 21598-21608, 2020 09 01.
Article in English | MEDLINE | ID: mdl-32817421

ABSTRACT

We tested cis-ApcΔ716/Smad4+/- and cis-ApcΔ716/Smad4+/-KrasG12D mice, which recapitulate key genetic abnormalities accumulating during colorectal cancer (CRC) tumorigenesis in humans, for responsiveness to anti-VEGF therapy. We found that even tumors in cis-ApcΔ716/Smad4+/-KrasG12D mice, although highly aggressive, were suppressed by anti-VEGF treatment. We tested the hypothesis that inflammation, a major risk factor and trigger for CRC, may affect responsiveness to anti-VEGF. Chemically induced colitis (CIC) in cis-ApcΔ716/Smad4+/- and cis-ApcΔ716/Smad4+/-KrasG12D mice promoted development of colon tumors that were largely resistant to anti-VEGF treatment. The myeloid growth factor G-CSF was markedly increased in the serum after induction of colitis. Antibodies blocking G-CSF, or its target Bv8/PROK2, suppressed tumor progression and myeloid cell infiltration when combined with anti-VEGF in CIC-associated CRC and in anti-VEGF-resistant CRC liver metastasis models. In a series of CRC specimens, tumor-infiltrating neutrophils strongly expressed Bv8/PROK2. CRC patients had significantly higher plasma Bv8/PROK2 levels than healthy volunteers and high plasma Bv8/PROK2 levels were inversely correlated with overall survival. Our findings establish Bv8/PROK2 as a translational target in CRC, in combination with anti-VEGF agents.


Subject(s)
Colorectal Neoplasms/genetics , Neutrophils/drug effects , Neutrophils/metabolism , Angiogenesis Inducing Agents/metabolism , Animals , Antibodies/immunology , Colonic Neoplasms/metabolism , Colorectal Neoplasms/metabolism , Female , Granulocyte Colony-Stimulating Factor/metabolism , Liver Neoplasms/metabolism , Male , Mice , Mice, Inbred C57BL , Models, Genetic , Myeloid Cells/metabolism , Neovascularization, Pathologic/pathology , Vascular Endothelial Growth Factor A/drug effects , Vascular Endothelial Growth Factor A/immunology , Vascular Endothelial Growth Factor A/metabolism
10.
Cancers (Basel) ; 12(8)2020 Jul 22.
Article in English | MEDLINE | ID: mdl-32708005

ABSTRACT

Some colorectal cancer patients harboring FGFR (fibroblast growth factor receptor) genetic alterations, such as copy number gain, mutation, and/or mRNA overexpression, were selected for enrollment in several recent clinical trials of FGFR inhibitor, because these genetic alterations were preclinically reported to be associated with FGFR inhibitor sensitivity as well as poor prognosis, invasiveness, and/or metastatic potential. However, few enrolled patients were responsive to FGFR inhibitors. Thus, practical strategies are eagerly awaited that can stratify patients for the subset that potentially responds to FGFR inhibitor chemotherapy. In the present study, we evaluated the sensitivity to FGFR inhibitor erdafitinib on 25 patient-derived tumor-initiating cell (TIC) spheroid lines carrying wild-type RAS and RAF genes, both in vitro and in vivo. Then, we assessed possible correlations between the sensitivity and the genetic/genomic data of the spheroid lines tested. Upon their exposure to erdafitinib, seven lines (7/25, 28%) responded significantly. Normal colonic epithelial stem cells were unaffected by the inhibitors. Moreover, the combination of erdafitinib with EGFR inhibitor erlotinib showed stronger growth inhibition than either drug alone, as efficacy was observed in 21 lines (84%) including 14 (56%) that were insensitive to erdafitinib alone. The in vitro erdafitinib response was accurately reflected on mouse xenografts of TIC spheroid lines. However, we found little correlation between their genetic/genomic alterations of TIC spheroids and the sensitivity to the FGFR inhibitor. Accordingly, we propose that direct testing of the patient-derived spheroids in vitro is one of the most reliable personalized methods in FGFR-inhibitor therapy of colorectal cancer patients.

11.
FASEB J ; 34(8): 10267-10285, 2020 08.
Article in English | MEDLINE | ID: mdl-32533805

ABSTRACT

Adaptive angiogenesis is necessary for tissue repair, however, it may also be associated with the exacerbation of injury and development of chronic disease. In these studies, we demonstrate that lung mesenchymal vascular progenitor cells (MVPC) modulate adaptive angiogenesis via lineage trace, depletion of MVPC, and modulation of ß-catenin expression. Single cell sequencing confirmed MVPC as multipotential vascular progenitors, thus, genetic depletion resulted in alveolar simplification with reduced adaptive angiogenesis. Following vascular endothelial injury, Wnt activation in MVPC was sufficient to elicit an emphysema-like phenotype characterized by increased MLI, fibrosis, and MVPC driven adaptive angiogenesis. Lastly, activation of Wnt/ß-catenin signaling skewed the profile of human and murine MVPC toward an adaptive phenotype. These data suggest that lung MVPC drive angiogenesis in response to injury and regulate the microvascular niche as well as subsequent distal lung tissue architecture via Wnt signaling.


Subject(s)
Airway Remodeling/physiology , Endothelium, Vascular/metabolism , Lung/metabolism , Mesenchymal Stem Cells/metabolism , Neovascularization, Pathologic/metabolism , Wnt Proteins/metabolism , Wnt Signaling Pathway/physiology , Adult , Aged , Animals , Cell Line , Endothelium, Vascular/pathology , Female , Humans , Lung/pathology , Male , Mesenchymal Stem Cells/pathology , Mice , Middle Aged , Neovascularization, Pathologic/pathology , Pulmonary Emphysema/metabolism , Pulmonary Emphysema/pathology , Vascular System Injuries/metabolism , Vascular System Injuries/pathology , Young Adult , beta Catenin/metabolism
12.
JCI Insight ; 5(10)2020 05 21.
Article in English | MEDLINE | ID: mdl-32369448

ABSTRACT

The Wnt/ß-catenin signaling pathway plays an important role in renal development and is reexpressed in the injured kidney and other organs. ß-Catenin signaling is protective in acute kidney injury (AKI) through actions on the proximal tubule, but the current dogma is that Wnt/ß-catenin signaling promotes fibrosis and development of chronic kidney disease (CKD). As the role of proximal tubular ß-catenin signaling in CKD remains unclear, we genetically stabilized (i.e., activated) ß-catenin specifically in murine proximal tubules. Mice with increased tubular ß-catenin signaling were protected in 2 murine models of AKI to CKD progression. Oxidative stress, a common feature of CKD, reduced the conventional T cell factor/lymphoid enhancer factor-dependent ß-catenin signaling and augmented FoxO3-dependent activity in proximal tubule cells in vitro and in vivo. The protective effect of proximal tubular ß-catenin in renal injury required the presence of FoxO3 in vivo. Furthermore, we identified cystathionine γ-lyase as a potentially novel transcriptional target of ß-catenin/FoxO3 interactions in the proximal tubule. Thus, our studies overturned the conventional dogma about ß-catenin signaling and CKD by showing a protective effect of proximal tubule ß-catenin in CKD and identified a potentially new transcriptional target of ß-catenin/FoxO3 signaling that has therapeutic potential for CKD.


Subject(s)
Forkhead Box Protein O3/metabolism , Kidney Tubules, Proximal/metabolism , Renal Insufficiency, Chronic/metabolism , Signal Transduction , beta Catenin/metabolism , Acute Kidney Injury/genetics , Acute Kidney Injury/metabolism , Acute Kidney Injury/pathology , Animals , Forkhead Box Protein O3/genetics , Kidney Tubules, Proximal/pathology , Male , Mice , Mice, Transgenic , Renal Insufficiency, Chronic/genetics , Renal Insufficiency, Chronic/pathology , beta Catenin/genetics
13.
Mol Neurobiol ; 57(3): 1704-1715, 2020 Mar.
Article in English | MEDLINE | ID: mdl-31823197

ABSTRACT

We previously reported that the inactivation (cKO) or the stabilization (cST) of ß-catenin in cells expressing the astrocyte-specific glutamate aspartate transporter (GLAST) is associated with the vulnerability or resilience to exhibit anxious/depressive-like behaviors, respectively, and to changes in hippocampal proliferation. Here, we used these cKO and cST ß-catenin mice to study the serotonergic system functionality associated with their behavioral/molecular phenotype. The activity of 5-HT1A receptors was assessed by (+)-8-OH-DPAT-induced hypothermia and [35S]GTPγS binding autoradiography. The animals' response to acute stress and the levels of extracellular serotonin (5-HT) in the medial prefrontal cortex (mPFC) were also assessed. cKO mice presented higher 5-HT1A autoreceptor functionality, lower 5-HT1A heteroreceptor functionality, and a decrease in extracellular 5-HT levels in the mPFC. These neurochemical changes were accompanied with a blunted physiological response to stress-induced hyperthermia. In contrast, cST mice showed a reduced 5-HT1A autoreceptor functionality and higher extracellular 5-HT levels in the mPFC after fluoxetine administration. Moreover, cST mice subjected to chronic corticosterone administration did not show a blunted response to fluoxetine. Our findings suggest the existence of a link between ß-catenin levels and 5-HT1A receptor functionality, which may be relevant to understand the neurobiological bases underlying the vulnerability or resilience to stress-related disorders.


Subject(s)
Anxiety/metabolism , Receptor, Serotonin, 5-HT1A/metabolism , Serotonin/metabolism , beta Catenin/metabolism , Animals , Behavior, Animal/drug effects , Corticosterone/metabolism , Depression/metabolism , Hippocampus/metabolism , Male , Mice , Prefrontal Cortex/metabolism
14.
Cancers (Basel) ; 11(12)2019 Nov 27.
Article in English | MEDLINE | ID: mdl-31783700

ABSTRACT

A lack of caudal-type homeobox transcription factor 2 (CDX2) protein expression has been proposed as a prognostic biomarker for colorectal cancer (CRC). However, the relationship between CDX2 levels and the survival of patients with stage II/III CRC along with the relationship between microRNAs (miRs) and CDX2 expression are unclear. Tissue samples were collected from patients with stage II/III CRC surgically treated at Kyoto University Hospital. CDX2 expression was semi-quantitatively evaluated by immunohistochemistry (IHC). The prognostic impacts of CDX2 expression on overall survival (OS) and relapse-free survival (RFS) were evaluated by multivariable statistical analysis. The expression of miRs regulating CDX2 expression and their prognostic impacts were analyzed using The Cancer Genome Atlas Program for CRC (TCGA-CRC). Eleven of 174 CRC tissues lacked CDX2 expression. The five-year OS and RFS rates of patients with CDX2-negative CRC were significantly lower than those of CDX2-positive patients. Multivariate analysis of clinicopathological features revealed that CDX2-negative status is an independent marker of poor prognosis in stage II/III CRC. miR-9-5p was shown to regulate CDX2 expression. TCGA-CRC analysis showed that high miR-9-5p expression was significantly associated with poor patient prognosis in stage II/III CRC. In conclusion, CDX2, the post-transcriptional target of microRNA-9-5p, is a useful prognostic biomarker in patients with stage II/III CRC.

15.
Nat Commun ; 10(1): 5023, 2019 11 04.
Article in English | MEDLINE | ID: mdl-31685822

ABSTRACT

Melanoma, the deadliest skin cancer, remains largely incurable at advanced stages. Currently, there is a lack of animal models that resemble human melanoma initiation and progression. Recent studies using a Tyr-CreER driven mouse model have drawn contradictory conclusions about the potential of melanocyte stem cells (McSCs) to form melanoma. Here, we employ a c-Kit-CreER-driven model that specifically targets McSCs to show that oncogenic McSCs are a bona fide source of melanoma that expand in the niche, and then establish epidermal melanomas that invade into the underlying dermis. Further, normal Wnt and Endothelin niche signals during hair anagen onset are hijacked to promote McSC malignant transformation during melanoma induction. Finally, molecular profiling reveals strong resemblance of murine McSC-derived melanoma to human melanoma in heterogeneity and gene signatures. These findings provide experimental validation of the human melanoma progression model and key insights into the transformation and heterogeneity of McSC-derived melanoma.


Subject(s)
Carcinogenesis/pathology , Melanocytes/pathology , Melanoma/pathology , Neoplastic Stem Cells/pathology , Animals , Carcinogenesis/metabolism , Cell Transformation, Neoplastic/pathology , Dermis/pathology , Disease Models, Animal , Epidermis/pathology , Homeostasis , Humans , Melanocytes/metabolism , Mice , Mutation/genetics , Neoplastic Stem Cells/metabolism , Phenotype , Promoter Regions, Genetic/genetics , Proto-Oncogene Proteins c-kit/metabolism , Tumor Microenvironment , Wnt Signaling Pathway
16.
Elife ; 82019 04 01.
Article in English | MEDLINE | ID: mdl-30932814

ABSTRACT

The circumventricular organs (CVOs) in the central nervous system (CNS) lack a vascular blood-brain barrier (BBB), creating communication sites for sensory or secretory neurons, involved in body homeostasis. Wnt/ß-catenin signaling is essential for BBB development and maintenance in endothelial cells (ECs) in most CNS vessels. Here we show that in mouse development, as well as in adult mouse and zebrafish, CVO ECs rendered Wnt-reporter negative, suggesting low level pathway activity. Characterization of the subfornical organ (SFO) vasculature revealed heterogenous claudin-5 (Cldn5) and Plvap/Meca32 expression indicative for tight and leaky vessels, respectively. Dominant, EC-specific ß-catenin transcription in mice, converted phenotypically leaky into BBB-like vessels, by augmenting Cldn5+vessels, stabilizing junctions and by reducing Plvap/Meca32+ and fenestrated vessels, resulting in decreased tracer permeability. Endothelial tightening augmented neuronal activity in the SFO of water restricted mice. Hence, regulating the SFO vessel barrier may influence neuronal function in the context of water homeostasis.


Subject(s)
Drinking Behavior , Subfornical Organ/physiology , Water/metabolism , Wnt Proteins/metabolism , Wnt Signaling Pathway , beta Catenin/metabolism , Animals , Capillary Permeability , Endothelial Cells/physiology , Homeostasis , Mice, Inbred C57BL , Zebrafish , Zebrafish Proteins/metabolism
17.
Biol Open ; 8(3)2019 Mar 18.
Article in English | MEDLINE | ID: mdl-30745437

ABSTRACT

Beta-catenin (CTNNB1) directs ectodermal appendage spacing by activating ectodysplasin A receptor (EDAR) transcription, but whether CTNNB1 acts by a similar mechanism in the prostate, an endoderm-derived tissue, is unclear. Here we examined the expression, function, and CTNNB1 dependence of the EDAR pathway during prostate development. In situ hybridization studies reveal EDAR pathway components including Wnt10b in the developing prostate and localize these factors to prostatic bud epithelium where CTNNB1 target genes are co-expressed. We used a genetic approach to ectopically activate CTNNB1 in developing mouse prostate and observed focal increases in Edar and Wnt10b mRNAs. We also used a genetic approach to test the prostatic consequences of activating or inhibiting Edar expression. Edar overexpression does not visibly alter prostatic bud formation or branching morphogenesis, and Edar expression is not necessary for either of these events. However, Edar overexpression is associated with an abnormally thick and collagen-rich stroma in adult mouse prostates. These results support CTNNB1 as a transcriptional activator of Edar and Wnt10b in the developing prostate and demonstrate Edar is not only important for ectodermal appendage patterning but also influences collagen organization in adult prostates.This article has an associated First Person interview with the first author of the paper.

18.
Dev Cell ; 48(1): 17-31.e6, 2019 01 07.
Article in English | MEDLINE | ID: mdl-30595533

ABSTRACT

Delineating molecular and cellular events that precede appendage morphogenesis has been challenging due to the inability to distinguish quantitative molecular differences between cells that lack histological distinction. The hair follicle (HF) dermal condensate (DC) is a cluster of cells critical for HF development and regeneration. Events that presage emergence of this distinctive population are poorly understood. Using unbiased single-cell RNA sequencing and in vivo methods, we infer a sequence of transcriptional states through which DC cells pass that begins prior to HF morphogenesis. Our data indicate that Wnt/ß-catenin signaling is required to progress into an intermediate stage that precedes quiescence and differentiation. Further, we provide evidence that quiescent DC cells are recent progeny of selectively proliferating cells present prior to morphogenesis and that are later identified in the peri-DC zone during DC expansion. Together, these findings provide an inferred path of molecular states that lead to DC cell differentiation.


Subject(s)
Cell Differentiation/physiology , Hair Follicle/cytology , Morphogenesis/physiology , Single-Cell Analysis , Dermis/cytology , Gene Expression Regulation, Developmental/physiology , Neurogenesis , Skin/metabolism , Wnt Signaling Pathway/physiology , beta Catenin/metabolism
19.
Nat Commun ; 9(1): 4903, 2018 11 21.
Article in English | MEDLINE | ID: mdl-30464171

ABSTRACT

Mammalian wounds typically heal by fibrotic repair without hair follicle (HF) regeneration. Fibrosis and regeneration are currently considered the opposite end of wound healing. This study sought to determine if scar could be remodeled to promote healing with HF regeneration. Here, we identify that activation of the Sonic hedgehog (Shh) pathway reinstalls a regenerative dermal niche, called dermal papilla, which is required and sufficient for HF neogenesis (HFN). Epidermal Shh overexpression or constitutive Smoothened dermal activation results in extensive HFN in wounds that otherwise end in scarring. While long-term Wnt activation is associated with fibrosis, Shh signal activation in Wnt active cells promotes the dermal papilla fate in scarring wounds. These studies demonstrate that mechanisms of scarring and regeneration are not distant from one another and that wound repair can be redirected to promote regeneration following injury by modifying a key dermal signal.


Subject(s)
Dermis/physiology , Fibroblasts/physiology , Hair Follicle/physiology , Hedgehog Proteins/metabolism , Wound Healing , Animals , Carcinoma, Basal Cell/etiology , Cicatrix/metabolism , Collagen/metabolism , Mice , Skin Neoplasms/etiology , Wnt Signaling Pathway
20.
Mol Cancer Ther ; 17(10): 2187-2196, 2018 10.
Article in English | MEDLINE | ID: mdl-29970483

ABSTRACT

Current genomic and gene expression analyses provide versatile tools to improve cancer chemotherapy. However, it is still difficult to predict whether each patient responds to a particular regimen or not. To predict chemosensitivity in each patient with colorectal cancer, we developed an evaluation method using the primary tumor-initiating cells (TIC, aka cancer stem cells) xenografted in nude mice subcutaneously (patient-derived spheroid xenografts; PDSX). Simultaneously, we also prepared the conventional patient-derived xenografts (PDX) from the same patients' tumors and compared the dosing results with those of PDSXs. We further compared the chemosensitivities of PDSXs with those of 7 patients who had been given regimens such as FOLFOX and FOLFIRI to treat their metastatic lesions. As per the results, the PDSX method provided much more precise and predictable tumor growth with less variance than conventional PDX, although both retained the epithelial characteristics of the primary tumors. Likewise, drug-dosing tests showed essentially the same results in PDXs and PDSXs, with stronger statistical power in PDSXs. Notably, the cancer chemosensitivity in each patient was precisely reflected in that of the PDSX mice along the clinical course until the resistance emerged at the terminal stage. This "paraclinical" xenograft trials using PDSXs may help selection of chemotherapy regimens efficacious for each patient, and, more importantly, avoiding inefficient ones by which the patient can lose precious time and QOL. Furthermore, the PDSX method may be employed for evaluations of off-label uses of cancer chemotherapeutics and compassionate uses of yet-unapproved new drugs in personalized therapies. Mol Cancer Ther; 17(10); 2187-96. ©2018 AACR.


Subject(s)
Colorectal Neoplasms/metabolism , Colorectal Neoplasms/pathology , Drug Resistance, Neoplasm , Neoplastic Stem Cells/drug effects , Neoplastic Stem Cells/metabolism , Animals , Biomarkers, Tumor , Cell Line, Tumor , Colorectal Neoplasms/diagnostic imaging , Colorectal Neoplasms/drug therapy , Disease Models, Animal , Female , Humans , Mice , Mutation , Positron-Emission Tomography , Tomography, X-Ray Computed , Xenograft Model Antitumor Assays
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