Similar Datasets
Project description:Hematopoietic stem cells (HSCs) have unique abilities to renew themselves and generate differentiated progenies of all blood cell lineages; however, how HSCs maintain the balance of self-renewal and lineage differentiation remains largely unknown. Herein, we showed that in mice the hematologic system deletion of Phosphatase, Mg2+/Mn2+ Dependent 1B (Ppm1b), a protein serine or threonine phosphatase highly expressed in HSCs, induces the suppression of phenotypic HSC expansion due to the blockage of cell cycle. Loss of Ppm1b impairs HSC self-renewal and hematopoietic reconstitution which were revealed by limiting dilution and BM transplantation assays. Through transcriptomic analysis, we observed that the Wnt/β-catenin pathway is downregulated in Ppm1b-deficient mice. Mechanistically, we provided evidence that Ppm1b interacted with β-catenin by performing a proximity ligation assay. Moreover, using an HN252 as a small molecule probe, we further found that Ppm1b inhibition suppressed the self-renewal of HSC and led to a decrease in common lymphoid progenitor cells, resulting in a reduction of B cells in the bone marrow and peripheral blood in turn. In the study we characterized an indispensable role of Ppm1b in regulating HSC self-renewal and B cell development via Wnt/β-catenin pathway.
2024-07-31 | GSE237746 | GEO
Project description:Hematopoietic stem cells (HSCs) have unique abilities to renew themselves and generate differentiated progenies of all blood cell lineages; however, how HSCs maintain the balance of self-renewal and lineage differentiation remains largely unknown. Herein, we showed that in mice the hematologic system deletion of Phosphatase, Mg2+/Mn2+ Dependent 1B (Ppm1b), a protein serine or threonine phosphatase highly expressed in HSCs, induces the suppression of phenotypic HSC expansion due to the blockage of cell cycle. Loss of Ppm1b impairs HSC self-renewal and hematopoietic reconstitution which were revealed by limiting dilution and BM transplantation assays. Through transcriptomic analysis, we observed that the Wnt/β-catenin pathway is downregulated in Ppm1b-deficient mice. Mechanistically, we provided evidence that Ppm1b interacted with β-catenin by performing a proximity ligation assay. Moreover, using an HN252 as a small molecule probe, we further found that Ppm1b inhibition suppressed the self-renewal of HSC and led to a decrease in common lymphoid progenitor cells, resulting in a reduction of B cells in the bone marrow and peripheral blood in turn. In the study we characterized an indispensable role of Ppm1b in regulating HSC self-renewal and B cell development via Wnt/β-catenin pathway.
2024-07-31 | GSE237745 | GEO
Project description:The Wnt/β-catenin signaling pathway is a key regulator of embryonic stem cell (ESC) self-renewal and differentiation. Constitutive activation of this pathway has been shown to increase mouse ESC (mESC) self-renewal and pluripotency gene expression. In this study, we generated a novel β-catenin knockout model in mESCs to delete putatively functional N-terminally truncated isoforms observed in previous knockout models. We showed that aberrant N-terminally truncated isoforms are not functional in mESCs. In the generated knockout line, we observed that canonical Wnt signaling is not active, as β-catenin ablation does not alter mESC transcriptional profile in serum/LIF culture conditions. In addition, we observed that Wnt signaling activation represses mESC spontaneous differentiation in a β-catenin-dependent manner. Finally, β-catenin (ΔC) isoforms can rescue β-catenin knockout self-renewal defects in mESCs cultured in serum-free medium and, albeit transcriptionally silent, cooperate with TCF1 and LEF1 to inhibit mESC spontaneous differentiation in a GSK3-dependent manner.
| S-EPMC7486219 | biostudies-literature
Project description:Liver tumor-initiating cells (TICs), the drivers for liver tumorigenesis, accounts for liver tumor initiation, metastasis, drug resistance and relapse. Wnt/β-catenin signaling pathway emerges as a critical modulator in liver TIC self-renewal. However, the molecular mechanism of Wnt/β-catenin initiation in liver tumorigenesis and liver TICs is still elusive. Here, we examined the expression pattern of 10 Wnt receptors (FZD1-FZD10), and found only FZD6 is overexpressed along with liver tumorigenesis. What's more, a divergent lncRNA of FZD6, termed lncFZD6, is also highly expressed in liver cancer and liver TICs. LncFZD6 drives liver TIC self-renewal and tumor initiation capacity through FZD6-dependent manner. LncFZD6 interacts with BRG1-embedded SWI/SNF complex and recruits it to FZD6 promoter, and thus drives the transcriptional initiation of FZD6 by chromatin remodeling. WNT5A, a ligand of FZD6, is highly expressed in liver non-TICs and drives the self-renewal of liver TICs through lncFZD6-BRG1-FZD6-dependent manner. Through FZD6 transcriptional regulation in cis, lncFZD6 activates Wnt/β-catenin signaling in liver TICs. LncFZD6-BRG1-Wnt5A/β-catenin pathway can serve as a target for liver TIC elimination. Altogether, lncFZD6 promotes Wnt/β-catenin activation and liver TIC self-renewal through BRG1-dependent FZD6 expression.
| S-EPMC5992127 | biostudies-literature
Project description:The Wnt/β-catenin signalling pathway is a key regulator of embryonic stem cell self-renewal and differentiation. Constitutive activation of this pathway has been shown to significantly increase mouse embryonic stem cell (mESC) self-renewal and pluripotency marker expression. In this study, we generated a novel β-catenin knock-out model in mESCs by using CRISPR/Cas9 technology to delete putatively functional N-terminally truncated isoforms observed in previous knock-out models. While we showed that aberrant N-terminally truncated isoforms are not functional in mESCS, we observed that canonical Wnt signalling is not active in mESCs, as β-catenin ablation does not alter mESC transcriptional profile in LIF-enriched culture conditions; on the other hand, Wnt signalling activation represses mESC spontaneous differentiation. We also showed that transcriptionally silent β-catenin (ΔC) isoforms can rescue β-catenin knock-out self-renewal defects in mESCs, cooperating with TCF1 and LEF1 in the inhibition of mESC spontaneous differentiation in a Gsk3 dependent manner.
2020-01-10 | GSE143340 | GEO
Project description:The nuclear receptor TLX (also known as NR2E1) is essential for adult neural stem cell self-renewal; however, the molecular mechanisms involved remain elusive. Here we show that TLX activates the canonical Wnt/beta-catenin pathway in adult mouse neural stem cells. Furthermore, we demonstrate that Wnt/beta-catenin signalling is important in the proliferation and self-renewal of adult neural stem cells in the presence of epidermal growth factor and fibroblast growth factor. Wnt7a and active beta-catenin promote neural stem cell self-renewal, whereas the deletion of Wnt7a or the lentiviral transduction of axin, a beta-catenin inhibitor, led to decreased cell proliferation in adult neurogenic areas. Lentiviral transduction of active beta-catenin led to increased numbers of type B neural stem cells in the subventricular zone of adult brains, whereas deletion of Wnt7a or TLX resulted in decreased numbers of neural stem cells retaining bromodeoxyuridine label in the adult brain. Both Wnt7a and active beta-catenin significantly rescued a TLX (also known as Nr2e1) short interfering RNA-induced deficiency in neural stem cell proliferation. Lentiviral transduction of an active beta-catenin increased cell proliferation in neurogenic areas of TLX-null adult brains markedly. These results strongly support the hypothesis that TLX acts through the Wnt/beta-catenin pathway to regulate neural stem cell proliferation and self-renewal. Moreover, this study suggests that neural stem cells can promote their own self-renewal by secreting signalling molecules that act in an autocrine/paracrine mode.
| S-EPMC2880892 | biostudies-other
Project description:In both mice and humans, pluripotent stem cells (PSCs) exist in at least two distinct states of pluripotency, known as the naïve and primed states. Our understanding of the intrinsic and extrinsic factors that enable PSCs to self-renew and to transition between different pluripotent states is important for understanding early development. In mouse embryonic stem cells (mESCs), Wnt proteins stimulate mESC self-renewal and support the naïve state. In human embryonic stem cells (hESCs), Wnt/β-catenin signaling is active in naïve-state hESCs and is reduced or absent in primed-state hESCs. However, the role of Wnt/β-catenin signaling in naïve hESCs remains largely unknown. Here, we demonstrate that inhibition of the secretion of Wnts or inhibition of the stabilization of β-catenin in naïve hESCs reduces cell proliferation and colony formation. Moreover, we show that addition of recombinant Wnt3a partially rescues cell proliferation in naïve hESCs caused by inhibition of Wnt secretion. Notably, inhibition of Wnt/β-catenin signaling in naïve hESCs did not cause differentiation. Instead, it induced primed hESC-like proteomic and metabolic profiles. Thus, our results suggest that naïve hESCs secrete Wnts that activate autocrine or paracrine Wnt/β-catenin signaling to promote efficient self-renewal and inhibit the transition to the primed state.
| S-EPMC5081574 | biostudies-literature
Project description:Wnt/?-catenin signaling, a highly conserved pathway through evolution, regulates key cellular functions including proliferation, differentiation, migration, genetic stability, apoptosis, and stem cell renewal. The Wnt pathway mediates biological processes by a canonical or noncanonical pathway, depending on the involvement of ?-catenin in signal transduction. ?-catenin is a core component of the cadherin protein complex, whose stabilization is essential for the activation of Wnt/?-catenin signaling. As multiple aberrations in this pathway occur in numerous cancers, WNT-directed therapy represents an area of significant developmental therapeutics focus. The recently described role of Wnt/?-catenin pathway in regulating immune cell infiltration of the tumor microenvironment renewed the interest, given its potential impact on responses to immunotherapy treatments. This article summarizes the role of Wnt/?-catenin pathway in cancer and ongoing therapeutic strategies involving this pathway.
| S-EPMC5420131 | biostudies-literature
Project description:Impaired epithelial regeneration is a crucial pathophysiological feature of ulcerative colitis (UC). Yes-associated protein (YAP1) appears to control cell proliferation and differentiation. In this study, we sought to identify the roles of YAP in intestinal epithelial cell (IEC) self-renewal, regeneration and tumorigenesis. We first observed that YAP was significantly reduced in 62.5% (45/72) of human UC tissues and it was dramatically enhanced during epithelial regeneration in a murine colitis model. Using lentiviral infection, we established a YAP-overexpression (YAPWT) mouse model. We then found that after tissue injury, YAPWT mice had increased epithelial cell self-renewal capacity and drastically restored intestinal crypt structure. Strikingly, these mice were more susceptible to colitis-associated cancer (CAC) in chemically induced carcinoma. Mechanistically, YAP and ?-catenin showed increased nuclear co-localization during regeneration after inflammation. Overexpressing YAP significantly improved IEC 'wound-healing' ability and increased the expression of both ?-catenin and the transcriptional targets of Wnt signalling Lgr5 and cyclin D1, whereas silencing ?-catenin in YAPWT cells attenuated this effect. Remarkably, we observed that YAP could directly interact with ?-catenin in the nucleus and formed a transcriptional YAP/?-catenin/TCF4 complex; Lgr5 and cyclin D1 were confirmed to be the target genes of this complex. In contrast, cancer cell proliferation and tumour development were suppressed by the phospho-mimetic YAP mutant. In summary, nuclear YAP-driven IEC proliferation could control epithelial regeneration after inflammation and may serve as a potential therapeutic target in UC. However, excessive YAP activation promoted CAC development.
| S-EPMC5833613 | biostudies-literature
Project description:Breast cancer stem cells (BCSCs) are considered to be responsible for recurrence in breast cancer. The 68?kDa Src-associated protein in mitosis (Sam68) has been linked to the development and progression of breast cancer; however, the posttranscriptional regulation and role of Sam68 in BCSC self-renewal remain unclear.Sam68 was ectopically overexpressed or knocked down using a siRNA; the self-renewal potential of breast cancer cell lines was assessed using flow cytometry, in vitro mammosphere culture and a xenograft model in NOD/SCID mice. Activation of beta-catenin was assessed by immunohistochemical staining, Western blotting, and luciferase reporter gene assays. The ArrayExpress dataset GSE45666 was used to identify conserved microRNAs downregulated in breast cancer; real-time PCR, Western blotting, luciferase reporter assay, and xenografted tumor model were used to confirm miR-204 regulated Sam68.We found that endogenous Sam68 expression correlated positively with the self-renewal potential of breast cancer cell lines. Overexpression of Sam68 promoted, whereas knockdown reduced, breast cancer cell self-renewal potential in vitro and tumorigenicity in vivo. The Wnt/beta-catenin pathway was identified as a functional mediator of Sam68-induced self-renewal in SKBR-3 and MCF-7 cells. Furthermore, miR-204 was found to be frequently downregulated in human breast cancer and confirmed to directly target Sam68; miR-204 inhibited the self-renewal of breast cancer cell lines by targeting and suppressing Sam68.Our study reveals that Sam68 is regulated by miR-204 and may play an important role in the self-renewal of BCSCs via activating the Wnt/beta-catenin pathway. Sam68 may represent a novel therapeutic target for breast cancer.
| S-EPMC5008509 | biostudies-literature