scholarly journals Wnt6 plays a complex role in maintaining human limbal stem/progenitor cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Clémence Bonnet ◽  
Denise Oh ◽  
Hua Mei ◽  
Sarah Robertson ◽  
Derek Chang ◽  
...  

AbstractThe corneal epithelium is consistently regenerated by limbal stem/progenitor cells (LSCs), a very small population of adult stem cells residing in the limbus. Several Wnt ligands, including Wnt6, are preferentially expressed in the limbus. To investigate the role of Wnt6 in regulating proliferation and maintenance of human LSCs in an in vitro LSC expansion setting, we generated NIH-3T3 feeder cells to overexpress different levels of Wnt6. Characterization of LSCs cultured on Wnt6 expressing 3T3 cells showed that high level of Wnt6 increased proliferation of LSCs. Medium and high levels of Wnt6 also increased the percentage of small cells (diameter ≤ 12 µm), a feature of the stem cell population. Additionally, the percentage of cells expressing the differentiation marker K12 was significantly reduced in the presence of medium and high Wnt6 levels. Although Wnt6 is mostly known as a canonical Wnt ligand, our data showed that canonical and non-canonical Wnt signaling pathways were activated in the Wnt6-supplemented LSC cultures, a finding suggesting that interrelationships between both pathways are required for LSC regulation.

2021 ◽  
Author(s):  
Clémence Bonnet ◽  
Denise Oh ◽  
Hua Mei ◽  
Sarah Robertson ◽  
Derek Chang ◽  
...  

Abstract The cornea is consistently regenerated by limbal stem/progenitor cells (LSCs), a very small population of adult stem cells residing in the limbus. Several Wnt ligands, including Wnt6, are preferentially expressed in the limbus. To investigate the role of Wnt6 in regulating proliferation and maintenance of human LSCs in an in vitro LSC expansion setting, we generated NIH-3T3 feeder cells to overexpress different levels of Wnt6. Characterization of LSCs cultured on Wnt6 expressing 3T3 cells showed that high levels of Wnt6 increased proliferation of LSCs. Medium and high levels of Wnt6 also increased the percentage of small cells (diameter ≤ 12 µm), a feature of the stem cell population. Additionally, the percentage of cells expressing the differentiation marker K12 was significantly reduced in the presence of medium and high Wnt6 levels. Although Wnt6 is mostly known as a canonical Wnt ligand, our data showed that canonical and non-canonical Wnt signaling pathways were activated in the Wnt6-supplemented LSC cultures, a finding suggesting that interrelationships between both pathways are required for LSC regulation.


2019 ◽  
Vol 14 (4) ◽  
pp. 305-319 ◽  
Author(s):  
Marietta Herrmann ◽  
Franz Jakob

The bone marrow hosts skeletal progenitor cells which have most widely been referred to as Mesenchymal Stem or Stromal Cells (MSCs), a heterogeneous population of adult stem cells possessing the potential for self-renewal and multilineage differentiation. A consensus agreement on minimal criteria has been suggested to define MSCs in vitro, including adhesion to plastic, expression of typical surface markers and the ability to differentiate towards the adipogenic, osteogenic and chondrogenic lineages but they are critically discussed since the differentiation capability of cells could not always be confirmed by stringent assays in vivo. However, these in vitro characteristics have led to the notion that progenitor cell populations, similar to MSCs in bone marrow, reside in various tissues. MSCs are in the focus of numerous (pre)clinical studies on tissue regeneration and repair.Recent advances in terms of genetic animal models enabled a couple of studies targeting skeletal progenitor cells in vivo. Accordingly, different skeletal progenitor cell populations could be identified by the expression of surface markers including nestin and leptin receptor. While there are still issues with the identity of, and the overlap between different cell populations, these studies suggested that specific microenvironments, referred to as niches, host and maintain skeletal progenitor cells in the bone marrow. Dynamic mutual interactions through biological and physical cues between niche constituting cells and niche inhabitants control dormancy, symmetric and asymmetric cell division and lineage commitment. Niche constituting cells, inhabitant cells and their extracellular matrix are subject to influences of aging and disease e.g. via cellular modulators. Protective niches can be hijacked and abused by metastasizing tumor cells, and may even be adapted via mutual education. Here, we summarize the current knowledge on bone marrow skeletal progenitor cell niches in physiology and pathophysiology. We discuss the plasticity and dynamics of bone marrow niches as well as future perspectives of targeting niches for therapeutic strategies.


2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
Dong Joon Lee ◽  
Yonsil Park ◽  
Wei-Shou Hu ◽  
Ching-Chang Ko

Osteogenic cells derived from rat multipotent adult progenitor cells (rMAPCs) were investigated for their potential use in bone regeneration. rMAPCs are adult stem cells derived from bone marrow that have a high proliferation capacity and the differentiation potential to multiple lineages. They may also offer immunomodulatory properties favorable for applications for regenerative medicine. rMAPCs were cultivated as single cells or as 3D aggregates in osteogenic media for up to 38 days, and their differentiation to bone lineage was then assessed by immunostaining of osteocalcin and collagen type I and by mineralization assays. The capability of rMAPCs in facilitating bone regeneration was evaluatedin vivoby the direct implantation of multipotent adult progenitor cell (MAPC) aggregates in rat calvarial defects. Bone regeneration was examined radiographically, histologically, and histomorphometrically. Results showed that rMAPCs successfully differentiated into osteogenic lineage by demonstrating mineralized extracellular matrix formationin vitroand induced new bone formation by the effect of rMAPC aggregatesin vivo. These outcomes confirm that rMAPCs have a good osteogenic potential and provide insights into rMAPCs as a novel adult stem cell source for bone regeneration.


2016 ◽  
Vol 202 (5-6) ◽  
pp. 269-280 ◽  
Author(s):  
Daniel Martinez Saez ◽  
Robson Tetsuo Sasaki ◽  
Adriana da Costa Neves ◽  
Marcelo Cavenaghi Pereira da Silva

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.


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Francesco Pasqualini ◽  
Moises Di Sante ◽  
João D Pereira ◽  
Piero Anversa ◽  
Marcello Rota ◽  
...  

The stem cell antigen c-kit characterizes a heterogeneous pool of human cardiac progenitor cells (hCPCs) that exhibit a remarkable degree of regenerative potential and are currently employed in clinical trials. While this hCPC pool contains distinct subpopulations of c-kit+ cells that preferentially differentiate into muscular or vascular cardiac cells, we hypothesize that hCPCs may be coerced to specify only along the cardiomyogenic lineage by manipulating the Wnt/β-catenin pathway. We report that pharmacological inhibition of the non-canonical Wnt pathway facilitated the commitment of more than >95% c-kit+ hCPCs to the cardiomyocyte lineage after 4 days in-vitro: this constitutes a substantially more homogeneous population than previously reported with dexamethasone treatment. The hCPC-derived myocytes stained positive for Nkx2.5, a transcription factor that orchestrates cardiomyogenic differentiation, and for the contractile protein sarcomeric α-actin. To test if we could push the cells towards a more mature phenotype, we mimicked the cyclic modulation of the Wnt pathway observed during development. While activation of Wnt signaling resulted in widespread cell death and reduction in cell size, subsequent Wnt inhibition prompted the spared cells to proliferate. With this protocol, hCPC-derived myocytes increased in size and displayed more mature cytoskeletal architectures. In contrast with dexamethasone treated cells, where the localization of α-sarcomeric actinin is mostly diffuse in the cytoplasm, here we observed both Z-bodies and Z-disks like structures. The latter exhibited a periodicity of ~1.6 um and were clustered in larger, more aligned actin bundles. This finding suggests that the tension developed along these cytoskeletal components may play a role in the recruitment of sarcomeric proteins. In conclusion, Wnt signaling inhibition in hCPCs may be sufficient to obtain a homogeneous population of cells with features of myocytes, characterized by improved cytoskeletal organization than dexamethasone treated cells and similar to that observed in myocytes derived from human induced pluripotent stem cells.


2014 ◽  
Vol 112 (1) ◽  
pp. 166-171 ◽  
Author(s):  
Wenyan Li ◽  
Jingfang Wu ◽  
Jianming Yang ◽  
Shan Sun ◽  
Renjie Chai ◽  
...  

The activation of cochlear progenitor cells is a promising approach for hair cell (HC) regeneration and hearing recovery. The mechanisms underlying the initiation of proliferation of postnatal cochlear progenitor cells and their transdifferentiation to HCs remain to be determined. We show that Notch inhibition initiates proliferation of supporting cells (SCs) and mitotic regeneration of HCs in neonatal mouse cochlea in vivo and in vitro. Through lineage tracing, we identify that a majority of the proliferating SCs and mitotic-generated HCs induced by Notch inhibition are derived from the Wnt-responsive leucine-rich repeat-containing G protein-coupled receptor 5 (Lgr5+) progenitor cells. We demonstrate that Notch inhibition removes the brakes on the canonical Wnt signaling and promotes Lgr5+ progenitor cells to mitotically generate new HCs. Our study reveals a new function of Notch signaling in limiting proliferation and regeneration potential of postnatal cochlear progenitor cells, and provides a new route to regenerate HCs from progenitor cells by interrupting the interaction between the Notch and Wnt pathways.


Blood ◽  
1997 ◽  
Vol 89 (9) ◽  
pp. 3104-3112 ◽  
Author(s):  
A. Blair ◽  
D.E. Hogge ◽  
L.E. Ailles ◽  
P.M. Lansdorp ◽  
H.J. Sutherland

Abstract Acute myeloid leukaemia (AML) is thought to be maintained by a small population of leukemic progenitor cells. To define the phenotype of such cells with long-term proliferative capacity in vitro and in vivo, we have used the production of leukemic clonogenic cells (CFU) after 2 to 8 weeks in suspension culture as a measure of these cells in vitro and compared their phenotype with that of cells capable of engrafting nonobese diabetic severe combined immune deficient (NOD/SCID) mice. Leukemic blast peripheral blood cells were evaluated for expression of CD34 and Thy-1 (CD90) antigens. The majority of AML blast cells at diagnosis lacked expression of Thy-1. Most primary CFU-blast and the CFU detected at up to 8 weeks from suspension cultures were CD34+/Thy-1−. AML cells that were capable of engrafting NOD/SCID mice were also found to have the CD34+/Thy-1− phenotype. However, significant engraftment was achieved using both CD34+/Thy-1− and CD34− subfractions from one AML M5 patient. These results suggest that while heterogeneity exists between individual patients, the leukemic progenitor cells that are capable of maintaining the disease in vitro and in vivo differ from normal hematopoietic progenitor cells in their lack of expression of Thy-1.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Maria G. Roubelakis ◽  
Ourania Trohatou ◽  
Nicholas P. Anagnou

Amniotic fluid (AF) and amniotic membrane (AM) have been recently characterized as promising sources of stem or progenitor cells. Both not only contain subpopulations with stem cell characteristics resembling to adult stem cells, such as mesenchymal stem cells, but also exhibit some embryonic stem cell properties like (i) expression of pluripotency markers, (ii) high expansion in vitro, or (iii) multilineage differentiation capacity. Recent efforts have been focused on the isolation and the detailed characterization of these stem cell types. However, variations in their phenotype, their heterogeneity described by different groups, and the absence of a single marker expressed only in these cells may prevent the isolation of a pure homogeneous stem cell population from these sources and their potential use of these cells in therapeutic applications. In this paper, we aim to summarize the recent progress in marker discovery for stem cells derived from fetal sources such as AF and AM, using novel methodologies based on transcriptomics, proteomics, or secretome analyses.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Zhao Zhang ◽  
Diana M. Iglesias ◽  
Rachel Corsini ◽  
LeeLee Chu ◽  
Paul Goodyer

During development, nephron progenitor cells (NPC) are induced to differentiate by WNT9b signals from the ureteric bud. Although nephrogenesis ends in the perinatal period, acute kidney injury (AKI) elicits repopulation of damaged nephrons. Interestingly, embryonic NPC infused into adult mice with AKI are incorporated into regenerating tubules. Since WNT/β-catenin signaling is crucial for primary nephrogenesis, we reasoned that it might also be needed for the endogenous repair mechanism and for integration of exogenous NPC. When we examined glycerol-induced AKI in adult mice bearing aβ-catenin/TCF reporter transgene, endogenous tubular cells reexpressed the NPC marker, CD24, and showed widespreadβ-catenin/TCF signaling. We isolated CD24+cells from E15 kidneys of mice with the canonical WNT signaling reporter. 40% of cells responded to WNT3ain vitroand when infused into glycerol-injured adult, the cells exhibitedβ-catenin/TCF reporter activity when integrated into damaged tubules. When embryonic CD24+cells were treated with aβ-catenin/TCF pathway inhibitor (IWR-1) prior to infusion into glycerol-injured mice, tubular integration of cells was sharply reduced. Thus, the endogenous canonicalβ-catenin/TCF pathway is reactivated during recovery from AKI and is required for integration of exogenous embryonic renal progenitor cells into damaged tubules. These events appear to recapitulate the WNT-dependent inductive process which drives primary nephrogenesis.


2016 ◽  
Vol 311 (2) ◽  
pp. C246-C254 ◽  
Author(s):  
Yadan Quan ◽  
Xinchun Zhang ◽  
Siying Xu ◽  
Kang Li ◽  
Feng Zhu ◽  
...  

Conjunctival integrity and preservation is indispensable for vision. The self-renewing capacity of conjunctival cells controls conjunctival homeostasis and regeneration; however, the source of conjunctival self-renewal and the underlying mechanism is currently unclear. Here, we characterize the biochemical phenotype and proliferative potential of conjunctival epithelial cells in adult mouse by detecting proliferation-related signatures and conducting clonal analysis. Further, we show that transcription factor 7-like 2 (T-cell-specific transcription factor 4), a DNA binding protein expressed in multiple types of adult stem cells, is highly correlated with proliferative signatures in basal conjunctival epithelia. Clonal studies demonstrated that Transcription factor 7-like 2 (Tcf7l2) was coexpressed with p63α and proliferating cell nuclear antigen (PCNA) in propagative colonies. Furthermore, Tcf7l2 was actively transcribed concurrently with conjunctival epithelial proliferation in vitro. Collectively, we suggest that Tcf7l2 may be involved in maintenance of stem/progenitor cells properties of conjunctival epithelial stem/progenitor cells, and with the fornix as the optimal site to isolate highly proliferative conjunctival epithelial cells in adult mice.


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