Thyroid hormone signaling controls hair follicle stem cell function

Observations in thyroid patients and experimental animals show that the skin is an important target for the thyroid hormones. We previously showed that deletion in mice of the thyroid hormone nuclear receptors TRα1 and TRβ (the main thyroid hormone–binding isoforms) results in impaired epidermal proliferation, hair growth, and wound healing. Stem cells located at the bulges of the hair follicles are responsible for hair cycling and contribute to the regeneration of the new epidermis after wounding. Therefore a reduction in the number or function of the bulge stem cells could be responsible for this phenotype. Bulge cells show increased levels of epigenetic repressive marks, can retain bromodeoxyuridine labeling for a long time, and have colony-forming efficiency (CFE) in vitro. Here we demonstrate that mice lacking TRs do not have a decrease of the bulge stem cell population. Instead, they show an increase of label-retaining cells (LRCs) in the bulges and enhanced CFE in vitro. Reduced activation of stem cells leading to their accumulation in the bulges is indicated by a strongly reduced response to mobilization by 12- O-tetradecanolyphorbol-13-acetate. Altered function of the bulge stem cells is associated with aberrant activation of Smad signaling, leading to reduced nuclear accumulation of β-catenin, which is crucial for stem cell proliferation and mobilization. LRCs of TR-deficient mice also show increased levels of epigenetic repressive marks. We conclude that thyroid hormone signaling is an important determinant of the mobilization of stem cells out of their niche in the hair bulge. These findings correlate with skin defects observed in mice and alterations found in human thyroid disorders.

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A Mouse Model for Studying Stem Cell Effects on Regeneration of Hair Follicle Outer Root Sheaths

Open Life Sciences ◽

10.1515/biol-2020-0005 ◽

2020 ◽

Vol 15 (1) ◽

pp. 41-50

Author(s):

Jingxu Guo ◽

Shuwei Li ◽

Hongyang Wang ◽

Tinghui Wu ◽

Zhenhui Wu ◽

...

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Mouse Model ◽

Hair Follicle ◽

Smooth Muscle Actin ◽

Hair Follicles ◽

Alpha Smooth Muscle Actin ◽

Papillary Structure ◽

Glass Membrane

AbstractObjectiveStem cells hold promise for treating hair loss. Here an in vitro mouse model was developed using outer root sheaths (ORSs) isolated from hair follicles for studying stem cell-mediated dermal papillary regeneration.MethodsUnder sterile conditions, structurally intact ORSs were isolated from hair follicles of 3-day-old Kunming mice and incubated in growth medium. Samples were collected daily for 5 days. Stem cell distribution, proliferation, differentiation, and migration were monitored during regeneration.ResultsCell proliferation began at the glass membrane periphery then spread gradually toward the membrane center, with the presence of CD34 and CD200 positive stem cells involved in repair initiation. Next, CD34 positive stem cells migrated down the glass membrane, where some participated in ORS formation, while other CD34 cells and CD200 positive cells migrated to hair follicle centers. Within the hair follicle matrix, stem cells divided, grew, differentiated and caused outward expansion of the glass membrane to form a dermal papillary structure containing alpha-smooth muscle actin. Neutrophils attracted to the wound site phagocytosed bacterial and cell debris to protect regenerating tissue from infection.ConclusionIsolated hair follicle ORSs can regenerate new dermal papillary structures in vitro. Stem cells and neutrophils play important roles in the regeneration process.

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5-Azacytidine-Induced Cardiomyocyte Differentiation of Very Small Embryonic-Like Stem Cells

Stem Cells International ◽

10.1155/2020/5162350 ◽

2020 ◽

Vol 2020 ◽

pp. 1-8

Author(s):

XiaoLin Sun ◽

HongXiao Li ◽

Ye Zhu ◽

Pei Xu ◽

QiSheng Zuo ◽

...

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Ethical Issues ◽

Troponin T ◽

Embryonic Stem ◽

Stem Cell Population ◽

Pacemaker Activity ◽

Stem Cell Markers ◽

Seed Cells

The use of stem cells in generating cell-based pacemaker therapies for bradyarrhythmia is currently being considered. Due to the propensity of stem cells to form tumors, as well as ethical issues surrounding their use, the seed cells used in cardiac biological pacemakers have limitations. Very small embryonic-like stem cells (VSELs) are a unique and rare adult stem cell population, which have the same structural, genetic, biochemical, and functional characteristics as embryonic stem cells without the ethical controversy. In this study, we investigated the ability of rat bone marrow- (BM-) derived VSELs to differentiate in vitro into cardiomyocytes by 5-Azacytidine (5-AzaC) treatment. The morphology of VSELs treated with 10 μM 5-AzaC increased in volume and gradually changed to cardiomyocyte-like morphology without massive cell death. Additionally, mRNA expression of the cardiomyocyte markers cardiac troponin-T (cTnT) and α-sarcomeric actin (α-actin) was significantly upregulated after 5-AzaC treatment. Conversely, stem cell markers such as Nanog, Oct-4, and Sox2 were continuously downregulated posttreatment. On day 14 post-5-AzaC treatment, the positive expression rates of cTnT and α-actin were 18.41±1.51% and 19.43±0.51%, respectively. Taken together, our results showed that rat BM-VSELs have the ability to differentiate into cardiomyocytes in vitro. These findings suggest that VSELs would be useful as seed cells in exploring the mechanism of biological pacemaker activity.

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Stem Cells from Human Exfoliated Deciduous Teeth: A Growing Literature

Cells Tissues Organs ◽

10.1159/000447055 ◽

2016 ◽

Vol 202 (5-6) ◽

pp. 269-280 ◽

Cited By ~ 20

Author(s):

Daniel Martinez Saez ◽

Robson Tetsuo Sasaki ◽

Adriana da Costa Neves ◽

Marcelo Cavenaghi Pereira da Silva

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Adult Stem Cells ◽

Current Knowledge ◽

Deciduous Teeth ◽

Easy Access ◽

Stem Cell Population ◽

Scientific Publications ◽

Human Exfoliated Deciduous Teeth

Adult stem cells research has been considered the most advanced sort of medical-scientific research, particularly stem cells from human exfoliated deciduous teeth (SHED), which represent an immature stem cell population. The purpose of this review is to describe the current knowledge concerning SHED from full-text scientific publications from 2003 to 2015, available in English language and based on the keyword and/or abbreviations ‘stem cells from human exfoliated deciduous teeth (SHED)', and individually presented as to the properties of SHED, immunomodulatory properties of SHED and stem cell banking. In summary, these cell populations are easily accessible by noninvasive procedures and can be isolated, cultured and expanded in vitro, successfully differentiated in vitro and in vivo into odontoblasts, osteoblasts, chondrocytes, adipocytes and neural cells, and present low immune reactions or rejection following SHED transplantation. Furthermore, SHED are able to remain undifferentiated and stable after long-term cryopreservation. In conclusion, the high proliferative capacity, easy access, multilineage differentiation capacity, noninvasiveness and few ethical concerns make stem cells from human exfoliated deciduous teeth the most valuable source of stem cells for tissue engineering and cell-based regenerative medicine therapies.

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ZIKA virus effects on neuroprogenitors are exacerbated by the main pyriproxyfen metabolite via thyroid hormone signaling disruption

10.1101/2020.11.03.366468 ◽

2020 ◽

Author(s):

Petra Spirhanzlova ◽

Anthony Sébillot ◽

Pieter Vancamp ◽

Jean-David Gothié ◽

Sébastien Le Mével ◽

...

Keyword(s):

Stem Cells ◽

Thyroid Hormone ◽

Brain Development ◽

Zika Virus ◽

Hormone Signaling ◽

Main Metabolite ◽

Eastern Brazil ◽

North Eastern

AbstractNorth-Eastern Brazil saw intensive application of the insecticide pyriproxyfen (PPF) during the microcephaly outbreak caused by Zika virus (ZIKV). ZIKV requires the neural RNA-binding protein Musashi-1 to replicate. TH represses MSI1. Being a suspected TH disruptor, we hypothesized that co-exposure to the main metabolite of PPF, 4’-OH-PPF, would exacerbate ZIKV effects through increased MSI1 expression. This was tested using in vitro mouse neurospheres and an in vivo TH signaling reporter model, Xenopus laevis. TH signaling was decreased by 4’-OH-PPF in both models. In mouse-derived neurospheres the metabolite reduced neuroprogenitor proliferation as well as markers of neuronal differentiation. The results demonstrated that 4’-OH-PPF significantly induced MSI1 at both the mRNA and protein level, as well as Fasn mRNA. Other TH target genes were also significantly modified. Importantly, several key genes implicated in neuroprogenitor fate and commitment were not dysregulated by 4’-OH-PPF alone, but were in combination with ZIKV infection. These included the neuroprogenitor markers Nestin, Egfr, Gfap, Dlx2 and Dcx. Unexpectedly, 4’-OH-PPF decreased ZIKV replication, although only at the fourth and last day of incubation, and RNA copy numbers stayed within the same order of magnitude. However, intracellular RNA content of neuroprogenitors was significantly decreased in the combined presence of the PPF metabolite and ZIKV. We conclude that 4’-OH-PPF interferes with TH action in vivo and in vitro, inhibiting neuroprogenitor proliferation. In the presence of ZIKV, TH signaling pathways crucial for cortical development are significantly impacted. This provides another example of viral effects that are exacerbated by drug or pesticide use.Significance statementIn 2015, an increase in children born with unusually small heads (microcephaly) in North-Eastern Brazil was linked to infection with the ZIKA virus. An insecticide with thyroid hormone disruptive properties was used in the same areas. We investigated whether simultaneous exposure to the insecticide could increase viral susceptibility. The main metabolite 4’-OH-PPF dysregulated thyroid hormone signaling pathways crucial for brain development in both models used. Neural stem cells proliferated less and contained more Musashi-1, a protein the virus needs to replicate. Infecting stem cells pre-exposed to the endocrine disruptor did not amplify viral replication, but aggravated expression of genes implicated in brain development. Our results suggest the insecticide is particularly deleterious to brain development in areas with ZIKA virus prevalence.

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Mechanotransductive Differentiation of Hair Follicle Stem Cells Derived from Aged Eyelid Skin into Corneal Endothelial-Like Cells

Stem Cell Reviews and Reports ◽

10.1007/s12015-021-10249-0 ◽

2021 ◽

Author(s):

Christian Olszewski ◽

Jessika Maassen ◽

Rebecca Guenther ◽

Claudia Skazik-Voogt ◽

Angela Gutermuth

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Hair Follicle ◽

Hair Follicles ◽

Adherent Cell ◽

Promising Alternative ◽

Eyelid Skin ◽

Hair Follicle Stem Cells ◽

Follicle Stem Cells

AbstractCorneal endothelial insufficiency is one of the leading causes of blindness. The main contemporary treatment for corneal blindness is endothelial keratoplasty, which, however, is unsatisfactory as a medical therapy due to the lack of donor corneas and graft rejection. Therefore, autologous stem cell-based corneal endothelial tissue substitutes may be a promising alternative to conventional grafts in the future. To address the age of most patients suffering from corneal endothelial deficiencies, we investigated the presence and potential of hair-derived stem cells from older tissue donors. Our studies revealed the presence of pluripotency- and neural crest-associated markers in tissue sections from blepharoplasty patients aged 50 to 80 years. In vitro outgrowths from eyelid hair follicles on collagen-coated tissue culture plates revealed a weak decrease in stem-cell potency. In contrast, cells within the spheres that spontaneously formed from the adherent cell layer retained full stem-cell potency and could be differentiated into cells of the ecto- meso and endodermal lineages. Although these highly potent hair follicle derived stem cells (HFSC) were only very slightly expandable, they were able to recognize the biomimicry of the Descemet’s-like topography and differentiate into corneal endothelial-like cells. In conclusion, HFSCs derived from epidermal skin of eyelid biopsies are a promising cell source to provide autologous corneal endothelial replacement for any age group of patients. Graphical Abstract

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Glioblastoma embryonic-like stem cells exhibit immune-evasive phenotype

10.1101/2021.12.07.471556 ◽

2021 ◽

Author(s):

Borja Sese ◽

Sandra Iniguez ◽

Miquel Arash Ensenat ◽

Pere Llinas ◽

Guillem Ramis ◽

...

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Cell Population ◽

Immune Evasion ◽

Cell Mass ◽

Induced Pluripotent Stem Cell ◽

Stem Cell Population ◽

Glioma Stem Cells ◽

Pluripotency Markers

Glioma stem cells (GSCs) are a subset of cells with self-renewal and tumor-initiating capacities that are thought to participate in drug resistance and immune evasion mechanisms in glioblastoma (GBM). Given GBM heterogeneity, we hypothesized that GSCs might also display cellular hierarchies associated with different degrees of stemness. We evaluated a single-cell RNA-seq glioblastoma dataset (n = 28) and identified a stem cell population co-expressing high levels of embryonic pluripotency markers, named core glioma stem cells (c-GSCs). This embryonic-like population represents 4.22% of the tumor cell mass, and pathway analysis revealed an upregulation of stemness and downregulation of immune-associated pathways. Using induced pluripotent stem cell technology, we generated an in vitro model of c-GSCs by reprogramming glioblastoma patient-derived cells into induced c-GSCs (ic-GSCs). Immunostaining of ic-GSCs showed high expression of embryonic pluripotency markers and downregulation of antigen presentation HLA proteins, mimicking its tumoral counterpart. Transcriptomic analysis revealed a strong agreement of enriched biological pathways between tumor c-GSCs and in vitro ic-GSCs (k = 0.71). Integration of ic-GSC DNA methylation and gene expression with chromatin state analysis of epigenomic maps (n = 833) indicated that polycomb repressive marks downregulate HLA genes in stem-like phenotype. Together, we identified c-GSCs as a GBM cell population with embryonic signatures and poor immunogenicity. Genome-scale transcriptomic and epigenomic profiling provide a valuable resource for studying immune evasion mechanisms governing c-GSCs and identifying potential therapeutic targets for GBM immunotherapy.

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Transplantable human thyroid organoids generated from embryonic stem cells to rescue hypothyroidism

10.1101/2021.12.01.470729 ◽

2021 ◽

Author(s):

Mirian Romitti ◽

Barbara de Faria da Fonseca ◽

Gilles Doumont ◽

Pierre Gillotay ◽

Adrien Tourneur ◽

...

Keyword(s):

Stem Cells ◽

Embryonic Stem Cells ◽

Thyroid Hormone ◽

Hormone Replacement ◽

Thyroid Tissue ◽

Embryonic Stem ◽

Normal Growth ◽

Human Thyroid ◽

New Therapeutic Approaches

The function of the thyroid gland is to capture iodide in order to synthesize hormones that act on almost all tissues and are essential for normal growth and metabolism. Low plasma levels of thyroid hormones lead to hypothyroidism, which is one of the most common disorder in humans which is not always satisfactorily treated by lifelong hormone replacement. Therefore, in addition to the lack of in vitro tractable models to study human thyroid development, differentiation and maturation, there is a need for new therapeutic approaches that involve replacement of thyroid tissue responsive to changing demands for thyroid hormone. Here we report the first transplantable thyroid organoids derived from human embryonic stem cells capable of restoring plasma thyroid hormone to athyreotic mice as a proof of concept for future therapeutic development.

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In vivo and in vitro stem cell function of c-kit- and Sca-1-positive murine hematopoietic cells

Blood ◽

10.1182/blood.v80.12.3044.bloodjournal80123044 ◽

1992 ◽

Vol 80 (12) ◽

pp. 3044-3050 ◽

Cited By ~ 2

Author(s):

S Okada ◽

H Nakauchi ◽

K Nagayoshi ◽

S Nishikawa ◽

Y Miura ◽

...

Keyword(s):

Stem Cells ◽

Bone Marrow ◽

Stem Cell ◽

Hematopoietic Stem Cells ◽

Cell Function ◽

Bone Marrow Cells ◽

Synergistic Effects ◽

Single Cells ◽

Hematopoietic Stem

c-kit is expressed on hematopoietic stem cells and progenitor cells, but not on lymphohematopoietic differentiated cells. Lineage marker- negative, c-kit-positive (Lin-c-kit+) bone marrow cells were fractionated by means of Ly6A/E or Sca-1 expression. Lin-c-kit+Sca-1+ cells, which consisted of 0.08% of bone marrow nucleated cells, did not contain day-8 colony-forming units-spleen (CFU-S), but 80% were day-12 CFU-S. One hundred cells rescued the lethally irradiated mice and reconstituted hematopoiesis. On the other hand, 2 x 10(3) of Lin-c- kit+Sca-1- cells formed 20 day-8 and 11 day-12 spleen colonies, but they could not rescue the lethally irradiated mice. These data indicate that Lin-c-kit+Sca-1+ cells are primitive hematopoietic stem cells and that Sca-1-cells do not contain stem cells that reconstitute hematopoiesis. Lin-c-kit+Sca-1+ cells formed no colonies in the presence of stem cell factor (SCF) or interleukin-6 (IL-6), and only 10% of them formed colonies in the presence of IL-3. However, approximately 50% of them formed large colonies in the presence of IL-3, IL-6, and SCF. Moreover, when single cells were deposited into culture medium by fluorescence-activated cell sorter clone sorting system, 40% of them proliferated on a stromal cell line (PA-6) and proliferated for more than 2 weeks. In contrast, 15% of the Lin-c- kit+Sca-1-cells formed colonies in the presence of IL-3, but no synergistic effects were observed in combination with SCF plus IL-6 and/or IL-3. Approximately 10% proliferated on PA-6, but most of them degenerated within 2 weeks. The population ratio of c-kit+Sca-1+ to c-kit+Sca-1- increased 2 and 4 days after exposure to 5-fluorouracil (5-FU). These results are consistent with the relative enrichment of highly proliferative colony-forming cells by 5-FU. These data show that, although c-kit is found both on the primitive hematopoietic stem cells and progenitors, Sca-1+ cells are more primitive and respond better than Sca-1- cells to a combination of hematopoietic factors, including SCF and stromal cells.

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Effect of Parthenolide on Stem Cells in Childhood Acute Lymphoblastic Leukaemia.

Blood ◽

10.1182/blood.v112.11.1341.1341 ◽

2008 ◽

Vol 112 (11) ◽

pp. 1341-1341

Author(s):

Paraskevi Diamanti ◽

Charlotte V Cox ◽

Allison Blair

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Acute Lymphoblastic Leukaemia ◽

Lymphoblastic Leukaemia ◽

Therapeutic Agents ◽

Stem Cell Population ◽

Normal Peripheral Blood ◽

Childhood Acute Lymphoblastic Leukaemia ◽

Short Term Exposure

Abstract Current therapies for the treatment of childhood acute lymphoblastic leukaemia (ALL) have resulted in vastly improved survival rates of around 80% in recent years. Despite these successes, around 15% of patients die of the disease and relapse is the most common cause of treatment failure. Intensification of treatment to prevent or treat relapse may not be a feasible approach due to an increased risk of significant adverse effects. It is possible that ALL may be maintained by a subpopulation of stem cells that are resistant to regimens designed to kill the bulk population and subsequent relapses may arise from these stem cells. Consequently, there is a need to assess the efficacy of therapeutic agents on ALL stem cells. We have previously shown that ALL cells that are capable of initiating and sustaining the disease in serial xenografts have a CD34+/CD19− phenotype. Furthermore, these putative ALL stem cells were resistant to treatment in vitro with dexamethasone and vincristine, two agents routinely used in the treatment of paediatric leukaemia. In this investigation we have examined the effects of the sesquiterpene lactone parthenolide (PTL), a natural compound which induces oxidative stress and inhibits NF-kB. PTL effectively eradicates stem cells in AML and B-CLL in vitro while sparing normal heamopoietic cells. Unsorted leukaemia cells from 11 cases, with mixed prognostic subgroups, were co-cultured with and without PTL at a range of 0–10μM for 18–24 hours. Cell viability and apoptosis were evaluated by flow cytometry using annexin V and propidium iodide staining. Four out of the 11 cases were relatively resistant to treatment with PTL with only small reductions in viability (<5%) and no significant effect on apoptosis, even at the highest dose evaluated. There was no correlation between the prognostic risk group and the response to PTL. Primary cells from the 4 resistant cases were sorted into CD34+/CD19+ and CD34+/CD19− subfractions to assess the effect of PTL on these cells. The effects of PTL on the CD34+/CD19+ population were similar to that observed with the unsorted leukaemia cells. The CD34+/CD19− population was completely resistant to treatment with PTL, with more cells surviving treatment than the unsorted cells (P=0.03). In the 7 responding cases, the viability of the unsorted cells decreased to 28.4±7.1% and 38±12% were apoptotic following treatment. Very similar effects were observed with the CD34+/CD19+ subfraction in these responding cases with viability reduced to 33.4±6% and 35.9±14% were apoptotic. In contrast, the CD34+/CD19− cells from these 7 cases were significantly resistant to PTL with viabilities >75% at all concentrations evaluated (P<0.003). Apoptosis was 2.6-fold lower at 10μM PTL in the CD34+/CD19− subfraction compared to the unsorted cells (P=0.05). FISH analyses were performed on the viable cells at the end of the time-course and confirmed that leukaemia cells were surviving treatment with PTL. CD34+/CD38− cells from normal peripheral blood samples were also found to be resistant to treatment with PTL and survival of these cells at 10μM was not significantly different to that observed in the CD34+/CD19− ALL population in all 11 cases (P=0.38). Studies to assess the functional capacity of PTL-treated ALL cells are ongoing. These data demonstrate that while PTL shows promising effects on the bulk leukaemia population in some ALL cases, it had no significant effect on the putative ALL stem cell population. In each case examined, the CD34+/CD19− cells were resistant to short term exposure to PTL and responded in a similar manner to normal haemopoietic stem cells. These findings highlight the importance of evaluating therapeutic agents in the context of leukaemia stem cell populations and not just on the bulk leukaemia. Future studies are warranted to gain insight into how the drug sensitivity of ALL stem cells may be mediated.

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