scholarly journals Dickkopf1 Up-Regulation Induced by a High Concentration of Dexamethasone Promotes Rat Tendon Stem Cells to Differentiate Into Adipocytes

2015 ◽  
Vol 37 (5) ◽  
pp. 1738-1749 ◽  
Author(s):  
Wan Chen ◽  
Hong Tang ◽  
Xiangzhou Liu ◽  
Mei Zhou ◽  
Jiqiang Zhang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Western Blotting ◽  
Molecular Mechanisms ◽  
Glycogen Synthase ◽  
Adipogenic Differentiation ◽  
High Concentration ◽  
Signaling Molecule ◽  
Tendon Stem Cells ◽  
Gsk 3Β ◽  
Canonical Wnt

Background/Aims: Dexamethasone (Dex)-induced spontaneous tendon rupture and decreased self-repair capability is very common in clinical practice. The metaplasia of adipose tissue in the ruptured tendon indicates that Dex may induce tendon stem cells (TSCs) to differentiate into adipocytes, but the mechanism remains unclear. In the present study, we used in vitro methods to investigate the effects of Dex on rat TSC differentiation and the molecular mechanisms underlying this process. Methods: First, we used qPCR and Western blotting to detect the expression of the adipogenic differentiation markers aP2 and C/EBPα after treating the TSCs with Dex. Oil red staining was used to confirm that high concentration Dex promoted adipogenic differentiation of rat TSCs. Next, we used qPCR and Western blotting to detect the effect of a high concentration of dexamethasone on molecules related to the canonical WNT/β-catenin pathway in TSCs. Results: Treating rat TSCs with Dex promoted the synthesis of the inhibitory molecule dickkopf1 (DKK1) at the mRNA and protein levels. Western blotting results further showed that Dex downregulated the cellular signaling molecule phosphorylated glycogen synthase kinase-3β (P-GSK-3 β (ser9)), upregulated P-GSK-3β (tyr216), and downregulated the pivotal signaling molecule β-catenin. Furthermore, DKK1 knockdown attenuated Dex-induced inhibition of the canonical WNT/β-catenin pathway and of the adipogenic differentiation of TSCs. Lithium chloride (LiCl, a GSK-3β inhibitor) reduced Dex-induced inhibition of the classical WNT/β-catenin pathway in TSCs and of the differentiation of TSCs to adipocytes. Conclusion: In conclusion, by upregulating DKK1 expression, reducing the level of P-GSK-3β (ser9), and increasing the level of P-GSK-3β (tyr216), Dex causes the degradation of β-catenin, the central molecule of the classical WNT pathway, thereby inducing rat TSCs to differentiate into adipocytes.

scholarly journals Wnt5a Signaling in Normal and Cancer Stem Cells

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Yan Zhou ◽  
Thomas J. Kipps ◽  
Suping Zhang
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cancer Progression ◽  
Molecular Mechanisms ◽  
Migration And Invasion ◽  
Target Cells ◽  
Dependent Manner ◽  
Self Renewal ◽  
Surface Receptors ◽  
Canonical Wnt

Wnt5a is involved in activating several noncanonical Wnt signaling pathways, which can inhibit or activate canonical Wnt/β-catenin signaling pathway in a receptor context-dependent manner. Wnt5a signaling is critical for regulating normal developmental processes, including stem cell self-renewal, proliferation, differentiation, migration, adhesion, and polarity. Moreover, the aberrant activation or inhibition of Wnt5a signaling is emerging as an important event in cancer progression, exerting both oncogenic and tumor suppressive effects. Recent studies show the involvement of Wnt5a signaling in regulating normal and cancer stem cell self-renewal, cancer cell proliferation, migration, and invasion. In this article, we review recent findings regarding the molecular mechanisms and roles of Wnt5a signaling in stem cells in embryogenesis and in the normal or neoplastic breast or ovary, highlighting that Wnt5a may have different effects on target cells depending on the surface receptors expressed by the target cell.

scholarly journals β-Catenin Regulates Wound Healing and IL-6 Expression in Activated Human Astrocytes

Biomedicines ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 479
Author(s):  
Venkata Viswanadh Edara ◽  
Shruthi Nooka ◽  
Jessica Proulx ◽  
Satomi Stacy ◽  
Anuja Ghorpade ◽  
...  
Keyword(s):  
Wound Healing ◽  
Molecular Mechanisms ◽  
Nuclear Translocation ◽  
Glycogen Synthase ◽  
Reactive Astrogliosis ◽  
Human Astrocytes ◽  
Tnf Α ◽  
Inflammatory Stimuli ◽  
Chemokine Ligand ◽  
Gsk 3Β

Reactive astrogliosis is prominent in most neurodegenerative disorders and is often associated with neuroinflammation. The molecular mechanisms regulating astrocyte-linked neuropathogenesis during injury, aging and human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) are not fully understood. In this study, we investigated the implications of the wingless type (Wnt)/β-catenin signaling pathway in regulating astrocyte function during gliosis. First, we identified that HIV-associated inflammatory cytokines, interleukin (IL)-1β and tumor necrosis factor (TNF)-α induced mediators of the Wnt/β-catenin pathway including β-catenin and lymphoid enhancer-binding factor (LEF)-1 expression in astrocytes. Next, we investigated the regulatory role of β-catenin on primary aspects of reactive astrogliosis, including proliferation, migration and proinflammatory responses, such as IL-6. Knockdown of β-catenin impaired astrocyte proliferation and migration as shown by reduced cyclin-D1 levels, bromodeoxyuridine incorporation and wound healing. HIV-associated cytokines, IL-1β alone and in combination with TNF-α, strongly induced the expression of proinflammatory cytokines including C-C motif chemokine ligand (CCL)2, C-X-C motif chemokine ligand (CXCL)8 and IL-6; however, only IL-6 levels were regulated by β-catenin as demonstrated by knockdown and pharmacological stabilization. In this context, IL-6 levels were negatively regulated by β-catenin. To better understand this relationship, we examined the crossroads between β-catenin and nuclear factor (NF)-κB pathways. While NF-κB expression was significantly increased by IL-1β and TNF-α, NF-κB levels were not affected by β-catenin knockdown. IL-1β treatment significantly increased glycogen synthase kinase (GSK)-3β phosphorylation, which inhibits β-catenin degradation. Further, pharmacological inhibition of GSK-3β increased nuclear translocation of both β-catenin and NF-κB p65 into the nucleus in the absence of any other inflammatory stimuli. HIV+ human astrocytes show increased IL-6, β-catenin and NF-κB expression levels and are interconnected by regulatory associations during HAND. In summary, our study demonstrates that HIV-associated inflammation increases β-catenin pathway mediators to augment activated astrocyte responses including migration and proliferation, while mitigating IL-6 expression. These findings suggest that β-catenin plays an anti-inflammatory role in activated human astrocytes during neuroinflammatory pathologies, such as HAND.

GH prevents adipogenic differentiation of mesenchymal stromal stem cells derived from human trabecular bone via canonical Wnt signaling

Bone ◽  
2018 ◽  
Vol 112 ◽  
pp. 136-144 ◽  
Author(s):  
Simona Bolamperti ◽  
Michela Signo ◽  
Alice Spinello ◽  
GianLuigi Moro ◽  
Gianfranco Fraschini ◽  
...  
Keyword(s):  
Stem Cells ◽  
Wnt Signaling ◽  
Trabecular Bone ◽  
Adipogenic Differentiation ◽  
Canonical Wnt Signaling ◽  
Human Trabecular Bone ◽  
Canonical Wnt ◽  
Stromal Stem Cells

scholarly journals β-Elemene inhibits the proliferation of primary human airway granulation fibroblasts by down-regulating canonical Wnt/β-catenin pathway

2018 ◽  
Vol 38 (2) ◽  
Author(s):  
Cheng Xue ◽  
Ling-Ling Hong ◽  
Jun-Sheng Lin ◽  
Xiang-Yang Yao ◽  
Ding-Hui Wu ◽  
...  
Keyword(s):  
Transforming Growth Factor ◽  
Nuclear Translocation ◽  
Glycogen Synthase ◽  
Smooth Muscle Actin ◽  
Chinese Drug ◽  
Cultured Fibroblasts ◽  
Human Airway ◽  
Normal Human ◽  
Gsk 3Β ◽  
Canonical Wnt

Benign airway stenosis is a clinical challenge because of recurrent granulation tissues. Our previous study proved that a Chinese drug, β-elemene, could effectively inhibit the growth of fibroblasts cultured from hyperplastic human airway granulation tissues, which could slow down the progression of this disease. The purpose of the present study is to find out the mechanism for this effect. We cultured fibroblasts from normal human airway tissues and human airway granulation tissues. These cells were cultured with 160 μg/ml normal saline (NS), different doses of β-elemene, or 10 ng/ml canonical Wnt/β-catenin pathway inhibitor (Dickkopf-1, DKK-1). The proliferation rate of cells and the expression of six molecules involved in canonical Wnt/β-catenin pathway, Wnt3a, glycogen synthase kinase-3β (GSK-3β), β-catenin, α-smooth muscle actin (α-SMA), transforming growth factor-β (TGF-β), and Collagen I (Col-I), were measured. At last, we used canonical Wnt/β-catenin pathway activator (LiCl) to further ascertain the mechanism of β-elemene. Canonical Wnt/β-catenin pathway is activated in human airway granulation fibroblasts. β-Elemene didn’t affect normal human airway fibroblasts; however, it had a dose–responsive inhibitive effect on the proliferation and expression of Wnt3a, non-active GSK-3β, β-catenin, α-SMA, TGF-β, and Col-I of human airway granulation fibroblasts. More importantly, it had the same effect on the expression and nuclear translocation of active β-catenin. All these effects were similar to 10 ng/ml DKK-1 and could be attenuated by 10 mM LiCl. Thus, β-elemene inhibits the proliferation of primary human airway granulation fibroblasts by down-regulating canonical Wnt/β-catenin pathway. This pathway is possibly a promising target to treat benign tracheobronchial stenosis.

scholarly journals The osteogenic differentiation of human adipose-derived stem cells is regulated through the let-7i-3p/LEF1/β-catenin axis under cyclic strain

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Yadong Luo ◽  
Ran Ge ◽  
Heming Wu ◽  
Xu Ding ◽  
Haiyang Song ◽  
...  
Keyword(s):  
Stem Cells ◽  
Flow Cytometry ◽  
Osteogenic Differentiation ◽  
Western Blotting ◽  
Adipogenic Differentiation ◽  
Cyclic Strain ◽  
Negative Regulator ◽  
Cell Counting ◽  
Adipose Derived Stem Cells ◽  
Loss Of Function

Abstract Background The Wnt/β-catenin pathway is involved in the osteogenic differentiation of human adipose-derived stem cells (hASCs) under cyclic strain. Very little is known about the role of microRNAs in these events. Methods Cells were obtained using enzyme digestion methods, and proliferation was detected using Cell Counting Kit 8. Cell cycles and immunophenotypes were detected by flow cytometry. The multilineage potential of hASCs was induced by induction media. Cyclic strain was applied to hASCs (0.5 Hz, 2 h/day, 6 days) to induce osteogenic differentiation and miRNA changes. Bioinformatic and dual-luciferase analyses confirmed lymphoid enhancer factor 1 (LEF1) as a potential target of let-7i-3p. The effect of let-7i-3p on LEF1 in hASCs transfected with a let-7i-3p mimic and inhibitor was analyzed by immunofluorescence. hASCs were transfected with a let-7i-3p mimic, inhibitor, or small interfering RNA (siRNA) against LEF1 and β-catenin. Quantitative real-time PCR (qPCR) and western blotting were performed to examine the osteogenic markers and Wnt/β-catenin pathway at the mRNA and protein levels, respectively. Immunofluorescence and western blotting were performed to confirm the activation of the Wnt/β-catenin pathway. Results Flow cytometry showed that 82.12% ± 5.83% of the cells were in G1 phase and 17.88% ± 2.59% of the cells were in S/G2 phase; hASCs were positive for CD29, CD90, and CD105. hASCs could have the potential for osteogenic, chondrogenic, and adipogenic differentiation. MicroRNA screening via microarray showed that let-7i-3p expression was decreased under cyclic strain. Bioinformatic and dual-luciferase analyses confirmed that LEF1 in the Wnt/β-catenin pathway was the target of let-7i-3p. Under cyclic strain, the osteogenic differentiation of hASCs was promoted by overexpression of LEF1and β-catenin and inhibited by overexpression of let-7i-3p. hASCs were transfected with let-7i-3p mimics and inhibitor. Gain- or loss-of-function analyses of let-7i-3p showed that the osteogenic differentiation of hASCs was promoted by decreased let-7i-3p expression and inhibited by increased let-7i-3p expression. Furthermore, high LEF1 expression inactivated the Wnt/β-catenin pathway in let-7i-3p-enhanced hASCs. In contrast, let-7i-3p inhibition activated the Wnt/β-catenin pathway. Conclusions Let-7i-3p, acting as a negative regulator of the Wnt/β-catenin pathway by targeting LEF1, inhibits the osteogenic differentiation of hASCs under cyclic strain in vitro.

MicroRNA-139-5p regulates C2C12 cell myogenesis through blocking Wnt/β-catenin signaling pathway

2015 ◽  
Vol 93 (1) ◽  
pp. 8-15 ◽  
Author(s):  
Lin Mi ◽  
Youlei Li ◽  
Qiangling Zhang ◽  
Chen Zhao ◽  
Ying Peng ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Molecular Mechanisms ◽  
Glycogen Synthase ◽  
C2c12 Cell ◽  
Negative Regulator ◽  
C2c12 Cells ◽  
Myoblast Differentiation ◽  
C2c12 Myoblast ◽  
Myoblast Proliferation ◽  
Gsk 3Β

MicroRNAs (miRNAs) are novel and potent regulators in myogenesis. However, the molecular mechanisms that many miRNAs regulate myoblast proliferation and differentiation which are largely unknown. Here, we found that miR-139-5p increased during C2C12 myoblast proliferation, while presenting an inverse trend during C2C12 myoblast differentiation. Flow cytometry and EdU incorporation assay showed that miR-139-5p slowed down the growth of C2C12 cells. Additional study demonstrated that ectopic introduction of miR-139-5p into C2C12 cells blocked myoblast differentiation. Importantly, we demonstrated for the first time that Wnt1, which is associated with the Wnt/β-catenin signaling pathway, was a direct target of miR-139-5p. Moreover, we found that the expression level of Wnt1 was suppressed significantly (p < 0.01) by miR-139-5p, which triggered inhibition of Wnt/β-catenin signaling through upregulation of glycogen synthase kinase 3 beta (GSK-3β; p < 0.05) and downregulation of p-GSK-3β (p < 0.01), β-catenin (p < 0.05), and nuclear β-catenin (p < 0.01). Taken together, these results suggest that miR-139-5p is an important negative regulator in myogenesis through blocking the Wnt1-mediated Wnt/β-catenin signaling pathway.

scholarly journals A divergent canonical WNT-signaling pathway regulates microtubule dynamics

2004 ◽  
Vol 164 (2) ◽  
pp. 243-253 ◽  
Author(s):  
Lorenza Ciani ◽  
Olga Krylova ◽  
Matthew J. Smalley ◽  
Trevor C. Dale ◽  
Patricia C. Salinas
Keyword(s):  
Wnt Signaling ◽  
Signaling Pathway ◽  
Transcriptional Activation ◽  
Glycogen Synthase ◽  
Wnt Signaling Pathway ◽  
Negative Regulator ◽  
Canonical Wnt Signaling ◽  
Microtubule Stability ◽  
Gsk 3Β ◽  
Canonical Wnt

Dishevelled (DVL) is associated with axonal microtubules and regulates microtubule stability through the inhibition of the serine/threonine kinase, glycogen synthase kinase 3β (GSK-3β). In the canonical WNT pathway, the negative regulator Axin forms a complex with β-catenin and GSK-3β, resulting in β-catenin degradation. Inhibition of GSK-3β by DVL increases β-catenin stability and TCF transcriptional activation. Here, we show that Axin associates with microtubules and unexpectedly stabilizes microtubules through DVL. In turn, DVL stabilizes microtubules by inhibiting GSK-3β through a transcription- and β-catenin–independent pathway. More importantly, axonal microtubules are stabilized after DVL localizes to axons. Increased microtubule stability is correlated with a decrease in GSK-3β–mediated phosphorylation of MAP-1B. We propose a model in which Axin, through DVL, stabilizes microtubules by inhibiting a pool of GSK-3β, resulting in local changes in the phosphorylation of cellular targets. Our data indicate a bifurcation in the so-called canonical WNT-signaling pathway to regulate microtubule stability.

scholarly journals Bone marrow derived stem cells facilitate axonal regeneration in a rat model of 2, 5-hexanedione-induced neuropathy via miRNA-dependent and independent routes

2021 ◽  
Author(s):  
Enjun Zuo ◽  
Shuhai Hu ◽  
Cong Zhang ◽  
Xiaoxia Shi ◽  
Zhaofei Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Stem Cells ◽  
Bone Marrow ◽  
Western Blotting ◽  
Rat Model ◽  
Molecular Mechanisms ◽  
Axon Regeneration ◽  
Autologous Transplantation ◽  
Mtor Inhibitors ◽  
Sciatic Nerves

Abstract Background Peripheral polyneuropathies are clinically difficult situations and can be caused by exposure to occupational hazardous materials, such as N-hexane, which is still being used in developing countries. Autologous transplantation with bone marrow-mesenchymal stem cells (BMSCs) could be a promising therapeutical approach but its effect on toxic chemical-induced neuropathy remains undetermined. The present study sought to understand whether BMSCs could improve axon regeneration in Hexane-caused polyneuropathies and attempted to understand the associated molecular mechanisms. Methods A rat model of 2,5-hexanedine (HD)-induced polyneuropathy was established by intraperitoneally injection of 400 mg/kg/day HD, 5 times/week for 5 weeks. After the development of characteristic phenotypes, rats were given a single bolus tail-vein injection of BMSCs (5×107 cells/kg) and followed-up for 5 weeks. Sciatic nerves of HD/HD + BMSCs treated rats, as a representative tissue for peripheral nerve, were analyzed using electron microscopy, immunohistochemistry, western blotting and RNA sequencing. To further dissect the underlying mechanism, cultured DRG neurons +/- Schwann cells were challenged with HD/BMSC-derived conditional medium (BMSC-CM), in the presence or absence of NGF/Akt/mTOR inhibitors, recombinant NGF, miRNA mimics or miRNA inhibitors and further tested for changes in cellular and molecular levels. Results BMSCs engrafting significantly improved motor function recovery. Accelerated axon regeneration in sciatic nerves was evidenced by transmission electron microscopy, GAP43 western blotting and MBP/SMI312 immunostaining. Increased NGF expression and signaling activation was evidenced in response to BMSC/BMSC-CM treatment. In cultured cells, BMSC-CM’s effect was abolished by anti-NGF antibody or TrkA inhibitor K252a but reinforced by recombinant NGF. The activation of PI3K-Akt-mTOR-CREB signaling was observed and Akt and mTOR inhibitors were shown to attenuate BMSCS-promoted axon regeneration. While NGF was shown to be secreted by BMSCs in culture medium, miRNA array suggested certain miRNAs might also participate to regulate NGF expression. Three let-7 family miRNAs, including let-7a-5p, let-7d-5p and let-7e-5p, and 69 other miRNAs were found to be differentially expressed in HD and HD/BMSC groups. The regulatory effect of let-7e-5p on NGF expression was examined using miRNA mimics and inhibitors. Conclusions Together, our study demonstrated that BMSC transplantation significantly improve axon regeneration in hexane-induced polyneuropathy by activating NGF-PI3K-Akt-mTOR-CREB signaling via two independent mechanisms.

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