scholarly journals Progesterone initiates Wnt-β-catenin signaling but estradiol is required for nuclear activation and synchronous proliferation of rat uterine stromal cells

2006 ◽  
Vol 191 (3) ◽  
pp. 537-548 ◽  
Author(s):  
Virginia Rider ◽  
Kazuto Isuzugawa ◽  
Meryl Twarog ◽  
Stacy Jones ◽  
Brent Cameron ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Wnt Signaling ◽  
Stromal Cells ◽  
Stromal Cell ◽  
Nuclear Translocation ◽  
Glycogen Synthase ◽  
Ovariectomized Rats ◽  
Urokinase Plasminogen Activator Receptor ◽  
Cell Cycle Entry ◽  
Gsk 3Β

Progesterone pretreatment of ovariectomized rat uteri increases the number of synchronously proliferating stromal cells in response to estradiol 17-β. To identify the signals involved in stimulating synchronous proliferation, sexually mature ovariectomized rats were injected with progesterone (2 mg) for 3 consecutive days. Estradiol 17-β (0.2 μg) was administered to initiate cell cycle entry. Uterine samples were removed at various times after hormone administration and changes in wingless (Wnt) pathway effectors and gene targets were identified by microarray. Progesterone pretreatment decreased glycogen synthase kinase-3β (GSK-3β) and increased expression of T-cell factor/lymphoid enhancer factor (TCF/LEF). GSK-3β protein decreased markedly in the uterine stroma of progesterone-pretreated uteri with the concomitant appearance of β-catenin in these stromal cells. Translocation of β-catenin from the cytosol to the nuclei in progesterone-pretreated stromal cells was stimulated in response to estradiol. β-Catenin binding to TCF/LEF increased (P<0.05) in progesterone-pretreated uteri in response to estradiol. Progesterone stimulated the expression of the Wnt target gene urokinase plasminogen activator receptor (uPA-R) in the periluminal uterine stromal cells. The expression of uPA-R increased in progesterone-pretreated stromal cells in response to estradiol administration. Together, the results indicate that progesterone initiates Wnt signaling in the uterine stroma by down-regulating GSK-3β. However, nuclear translocation of β-catenin and sufficient complex formation with TCF/LEF to activate stromal cell cycle entry requires estradiol. Stimulation of a uterine stromal cell line to proliferate and differentiate resulted in β-catenin accumulation, suggesting that endocrine-dependent Wnt signaling controls proliferation and differentiation (decidualization).

scholarly journals Reversible cell-cycle entry in adult kidney podocytes through regulated control of telomerase and Wnt signaling

2011 ◽  
Vol 18 (1) ◽  
pp. 111-119 ◽  
Author(s):  
Marina Shkreli ◽  
Kavita Y Sarin ◽  
Matthew F Pech ◽  
Natalia Papeta ◽  
Woody Chang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Wnt Signaling ◽  
Cell Cycle Entry ◽  
Adult Kidney

scholarly journals Dextromethorphan Attenuates NADPH Oxidase-Regulated Glycogen Synthase Kinase 3β and NF-κB Activation and Reduces Nitric Oxide Production in Group A Streptococcal Infection

2018 ◽  
Vol 62 (6) ◽  
pp. e02045-17 ◽  
Author(s):  
Chia-Ling Chen ◽  
Miao-Huei Cheng ◽  
Chih-Feng Kuo ◽  
Yi-Lin Cheng ◽  
Ming-Han Li ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nadph Oxidase ◽  
Nuclear Translocation ◽  
Glycogen Synthase ◽  
Glycogen Synthase Kinase ◽  
Streptococcal Toxic Shock Syndrome ◽  
Glycogen Synthase Kinase 3Β ◽  
Diphenylene Iodonium ◽  
Group A ◽  
Gsk 3Β

ABSTRACTGroup AStreptococcus(GAS) is an important human pathogen that causes a wide spectrum of diseases, including necrotizing fasciitis and streptococcal toxic shock syndrome. Dextromethorphan (DM), an antitussive drug, has been demonstrated to efficiently reduce inflammatory responses, thereby contributing to an increased survival rate of GAS-infected mice. However, the anti-inflammatory mechanisms underlying DM treatment in GAS infection remain unclear. DM is known to exert neuroprotective effects through an NADPH oxidase-dependent regulated process. In the present study, membrane translocation of NADPH oxidase subunit p47phoxand subsequent reactive oxygen species (ROS) generation induced by GAS infection were significantly inhibited via DM treatment in RAW264.7 murine macrophage cells. Further determination of proinflammatory mediators revealed that DM effectively suppressed inducible nitric oxide synthase (iNOS) expression and NO, tumor necrosis factor alpha, and interleukin-6 generation in GAS-infected RAW264.7 cells as well as in air-pouch-infiltrating cells from GAS/DM-treated mice. GAS infection caused AKT dephosphorylation, glycogen synthase kinase-3β (GSK-3β) activation, and subsequent NF-κB nuclear translocation, which were also markedly inhibited by treatment with DM and an NADPH oxidase inhibitor, diphenylene iodonium. These results suggest that DM attenuates GAS infection-induced overactive inflammation by inhibiting NADPH oxidase-mediated ROS production that leads to downregulation of the GSK-3β/NF-κB/NO signaling pathway.

scholarly journals cGMP-dependent protein kinase II determines β-catenin accumulation that is essential for uterine decidualization in mice

2019 ◽  
Vol 317 (6) ◽  
pp. C1115-C1127
Author(s):  
Yang Zhang ◽  
Lu Yan ◽  
Jiali Liu ◽  
Sheng Cui ◽  
Jingtao Qiu
Keyword(s):  
Protein Kinase ◽  
Stromal Cells ◽  
Glycogen Synthase ◽  
Regulatory Function ◽  
Dependent Protein Kinase ◽  
Cgmp Dependent Protein Kinase ◽  
Decidual Cells ◽  
Proliferation And Differentiation ◽  
Dependent Protein ◽  
Gsk 3Β

In the early phase of pregnancy, decidualization is an indispensable event after mammal embryo implantation, accompanied by proliferation and differentiation of uterine stromal cells. Type II cGMP-dependent protein kinase (Prkg2) belongs to the family of serine/threonine kinase, which plays multiple roles in cellular signaling pathways to control proliferation and differentiation. However, the regulatory function and molecular mechanism of Prkg2 in decidualization are still unknown. In this study, we show that Prkg2 has a gradually increased expression pattern during peri-implantation and artificial decidualization, and the expression of Prkg2 is induced by estrogen and progesterone in the ovariectomized mouse uteri and primary cultured uterine stromal cells, the process of which is blocked by treating with estrogen receptor (ER) antagonist (ICI-182,780) and progesterone receptor (PR) antagonist (RU-486). Inhibition of Prkg2 activity by HA-100 promotes uterine stromal cell proliferation but compromises decidualization with decreased expression of prolactin family 8, subfamily a, member 2. In addition, the functional regulation of decidualization by Prkg2 is accomplished by its induced phosphorylation of glycogen synthase kinase-3β (GSK-3β) at serine-9, which results in accumulation of β-catenin in the decidual cells. Taken together, our findings demonstrate that estrogen and progesterone upregulate the expression of Prkg2 in uterine stromal cells depending on ER and PR; Prkg2 promotes phosphorylation of GSK-3β at serine-9 and inactivates it, leading to the accumulation of β-catenin and promoting the process of decidualization. In addition to revealing the regulatory mechanism of Prkg2 that ensures the success of uterine decidualization, our findings will contribute to the understanding in the maintenance of early pregnancy.

Wnt/β-catenin signaling activates growth-control genes during overload-induced skeletal muscle hypertrophy

2005 ◽  
Vol 289 (4) ◽  
pp. C853-C859 ◽  
Author(s):  
Dustin D. Armstrong ◽  
Karyn A. Esser
Keyword(s):  
Skeletal Muscle ◽  
Wnt Signaling ◽  
Signaling Pathway ◽  
Muscle Hypertrophy ◽  
Glycogen Synthase ◽  
Wnt Signaling Pathway ◽  
Growth Control ◽  
Skeletal Muscle Hypertrophy ◽  
Study Results ◽  
Gsk 3Β

β-Catenin is a transcriptional activator shown to regulate the embryonic, postnatal, and oncogenic growth of many tissues. In most research to date, β-catenin activation has been the unique downstream function of the Wnt signaling pathway. However, in the heart, a Wnt-independent mechanism involving Akt-mediated phosphorylation of glycogen synthase kinase (GSK)-3β was recently shown to activate β-catenin and regulate cardiomyocyte growth. In this study, results have identified the activation of the Wnt/β-catenin pathway during hypertrophy of mechanically overloaded skeletal muscle. Significant increases in β-catenin were determined during skeletal muscle hypertrophy. In addition, the Wnt receptor, mFrizzled (mFzd)-1, the signaling mediator disheveled-1, and the transcriptional co-activator, lymphocyte enhancement factor (Lef)-1, are all increased during hypertrophy of the overloaded mouse plantaris muscle. Experiments also determined an increased association between GSK-3β and the inhibitory frequently rearranged in advanced T cell-1 protein with no increase in GSK-3β phosphorylation (Ser9). Finally, skeletal muscle overload resulted in increased nuclear β-catenin/Lef-1 expression and induction of the transcriptional targets c-Myc, cyclin D1, and paired-like homeodomain transcription factor 2. Thus this study provides the first evidence that the Wnt signaling pathway induces β-catenin/Lef-1 activation of growth-control genes during overload induced skeletal muscle hypertrophy.

scholarly journals Laforin Negatively Regulates Cell Cycle Progression through Glycogen Synthase Kinase 3β-Dependent Mechanisms

2008 ◽  
Vol 28 (23) ◽  
pp. 7236-7244 ◽  
Author(s):  
Runhua Liu ◽  
Lizhong Wang ◽  
Chong Chen ◽  
Yan Liu ◽  
Penghui Zhou ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Growth ◽  
Cyclin D1 ◽  
Tumor Suppression ◽  
Cell Cycle Progression ◽  
Glycogen Synthase ◽  
Glycogen Synthase Kinase ◽  
Glycogen Synthase Kinase 3Β ◽  
Cycle Progression ◽  
Gsk 3Β

ABSTRACT Glycogen synthase kinase 3β (GSK-3β) represses cell cycle progression by directly phosphorylating cyclin D1 and indirectly regulating cyclin D1 transcription by inhibiting Wnt signaling. Recently, we reported that the Epm2a-encoded laforin is a GSK-3β phosphatase and a tumor suppressor. The cellular mechanism for its tumor suppression remains unknown. Using ex vivo thymocytes and primary embryonic fibroblasts from Epm2a −/− mice, we show here a general function of laforin in the cell cycle regulation and repression of cyclin D1 expression. Moreover, targeted mutation of Epm2a increased the phosphorylation of Ser9 on GSK-3β while having no effect on the phosphorylation of Ser21 on GSK-3α. In the GSK-3β+/+ but not the GSK-3β−/− cells, Epm2a small interfering RNA significantly enhanced cell growth. Consistent with an increased level of cyclin D1, the phosphorylation of retinoblastoma protein (Rb) and the levels of Rb-E2F-regulated genes cyclin A, cyclin E, MCM3, and PCNA are also elevated. Inhibitors of GSK-3β selectively increased the cell growth of Epm2a +/+ but not of Epm2a −/− cells. Taken together, our data demonstrate that laforin is a selective phosphatase for GSK-3β and regulates cell cycle progression by GSK-3β-dependent mechanisms. These data provide a cellular basis for the tumor suppression activity of laforin.

scholarly journals Cyclin G1 inhibits the proliferation of mouse endometrial stromal cell in decidualization

2017 ◽  
Vol 69 (1) ◽  
pp. 71-81
Author(s):  
Qian Xu ◽  
Dong-zhi Yuan ◽  
Sheng Zhang ◽  
Ting Qu ◽  
Shi-mao Zhang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Stromal Cells ◽  
Stromal Cell ◽  
Embryo Implantation ◽  
Negative Regulator ◽  
Cell Cycle Regulators ◽  
Cyclin G1 ◽  
Decidual Cells

Uterine stromal cell decidualization is a dynamic physiological process in which cell proliferation, differentiation and apoptosis are orchestrated and occur in a temporal and cell-specific manner. This process is important for successful embryo implantation. Many cell-cycle regulators are involved in decidualization. The protein cyclin G1 is a unique regulator of the cell cycle with dual functions in cell proliferation. It was reported that cyclin G1 is expressed in mouse uterine stromal cells during the period of peri-implantation. To prove the function of cyclin G1 in mouse uterine stromal cells during this period, immunohistochemistry was used to stain mouse uterine tissues on days 4-8 of pregnancy. The results showed obvious spatial and temporal expression of cyclin G1 in uterine stromal cells, and that it is expressed in the cells of the primary decidual zone (PDZ) on day 5 and secondary decidual zone (SDZ) on days 6 and 7, when the stromal cells experienced active proliferation and differentiation was initiated. Applying the decidualization model of cultured primary stromal cells in vitro, we further revealed that the expression of cyclin G1 is associated with decidualization of stromal cells induced by medroxyprogesterone acetate (MPA) and estradiol-17? (E2). RNA interference was used for the knockdown of cyclin G1 in the induced decidual cells. Flow cytometry analysis indicated that the proportion of cells in the S stage was increased, and decreased in the G2/M phase. Our study indicates that cyclin G1, as a negative regulator of the cell cycle, plays an important role in the process of decidualization in mouse uterine stromal cells by inhibiting cell-cycle progression.

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.

AT7519, a Novel Small Molecule Multi-Cyclin Dependent Kinase Inhibitor, Induces Apoptosis in Multiple Myeloma VIA GSK3β

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 251-251 ◽  
Author(s):  
Loredana Santo ◽  
Sonia Vallet ◽  
Teru Hideshima ◽  
Diana Cirstea ◽  
Samantha Pozzi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Multiple Myeloma ◽  
Small Molecule ◽  
Glycogen Synthase ◽  
Group Versus ◽  
Specific Inhibitor ◽  
Control Group ◽  
Rna Pol Ii ◽  
Pol Ii ◽  
Gsk 3Β

Abstract Cyclin dependent kinases (CDKs) and their cyclin complexes play a crucial role in cell cycle control and transcriptional regulation. In multiple myeloma (MM), the abnormal activation of different CDKs and their cyclin partners, especially CDK4/cyclin D1 and CDK6/Cyclin D2, mediate uncontrolled cell cycle progression. Therefore CDKs represent promising novel therapeutic targets for MM. Additionally the cytokine dependent PI3K/Akt signaling pathway mediates growth, survival, drug resistance, migration and cell cycle regulation in MM. Activated Akt in turn phosphorylates downstream target molecules like glycogen synthase kinase (GSK)-3 β impacting growth and survival. Here we investigated the preclinical activity of a novel small-molecule multi-CDK inhibitor, AT7519 in MM. In vitro kinase assays demonstrated more potent inhibition of CDK 1, 2, 4, 5 and 9 compared to CDK 3, 6, and 7. AT7519 also demonstrated potent inhibitory activity against GSK-3 β. No significant inhibitory effects against other kinases were observed. We next investigated the growth inhibitory effect of AT7519 on MM cell lines. Maximal cytotoxicity was observed in 48 hour culture with IC50 values ranging from 0.5μM (MM.1S, U266) to 4 μM (MM1R). AT7519 was also effective against primary tumor cells from MM patients with no significant cytotoxicity noted in peripheral blood mononuclear cells from healthy volunteers. To delineate the underlying mechanism of cytotoxicity induced by AT7519, cell cycle analysis using PI staining in MM.1S cell line was performed. No significant accumulation of cells in a particular phase of cell cycle was noted; however, AT7519 showed an increased sub-G1 population, indicative of apoptosis, which was confirmed by Annexin V+PI+ staining and associated with caspase-8-9 and -3 cleavage. Importantly, we found that AT7519 markedly inhibited phosphorylation (serine 2 and serine 5 sites) of the carboxyl terminal domain of RNA polymerase II (RNA pol II) within 6 hours of treatment. Non-cell cycle CDKs including CDK9 are responsible for phosphorylation and activation of RNA pol II. Similarly, AT7519 also inhibited phosphorylation of GSK-3β while no significant effects on CDK expression levels were evident at early time points. To investigate whether there was a correlation between inhibition of phosphorylation of GSK-3β and RNA pol II, MM.1S cells were cultured with α-amanitin, a specific inhibitor of RNA pol II. Although phosphorylation of RNA pol II was significantly inhibited, phosphorylation of GSK-3β was not altered by amanitin (10 μM for up to 24 hours). These results suggest that GSK-3β and RNA pol II dephosphorylation at serine 2 and serine 5 may be two independent mechanisms by which AT7519 induces apoptosis in MM cells. Ongoing studies are confirming the role of GSK-3 β in AT7519 induced cytotoxicity of MM cells. Finally, the in vivo efficacy of AT7519 was examined using a xenograft mouse model of human MM. Mice treated with AT7519 demonstrated slower tumor growth compared to the control group without adverse effects. Moreover, AT7519 resulted in a significant prolongation in median overall survival in treated mice (40 days in the treatment group versus 27.5 days in the control cohort, p = 0.0324). In conclusion, these results show significant anti-MM activity of AT7519, and provide the rationale for its clinical evaluation in MM.

Bortezomib Can Overcome Stroma-Mediated Chemotherapy Resistance in Acute Lymphoblastic Leukemia.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2475-2475
Author(s):  
Ibraheem H. Motabi ◽  
Julie Ritchey ◽  
Matthew Holt ◽  
John F. DiPersio
Keyword(s):  
Cell Cycle ◽  
Flow Cytometry ◽  
Cell Line ◽  
Stromal Cells ◽  
Stromal Cell ◽  
S Phase ◽  
Cxcr4 Expression ◽  
Leukemic Cells ◽  
Apoptosis Rate ◽  
G2 Cells

Abstract Abstract 2475 Background: In spite of excellent results of chemotherapy induction resulting in high rates of complete remission in patients with ALL, relapse remains a major problem. This is likely due to a subset of leukemic cells that are chemotherapy resistant. The interaction between bone marrow stromal cells and leukemia cells protects leukemic cells from the cytotoxic effects of chemotherapy. Bortezomib is a proteozome inhibitor used to treat lymphoid malignancies. It has been shown to mobilize stem cells in myeloma patients. We hypothesized that, in addition to its direct cytotoxic effect, bortezomib can also overcome the protective effect of stromal cells by disrupting CXCR4 signaling through inhibition of CXCR4 turnover normally regulated by proteosome degradation. Methods: We used the human B-cell ALL cell lines, G2 and BV-173, and two human BM stromal cell lines, HS-5 and HS-27a for our studies. G2 cells were incubated alone or co-cultured with HS-5 or HS-27a for 24 hours then treated with RPMI (control), cytarabine, doxorubicin, or bortezomib. After 48 hours, cells were harvested and stained with FITC-conjugated anti-human annexin V antibody and analyzed by flow cytometry. To test the effect of bortezomib on CXCR4 expression, G2 cells were incubated with or without stromal cells and treated with cytarabine or bortezomib for 18 hours or left untreated. Then cells were stained with PE-conjugated anti-human CXCR4 antibody (clone 1D9) and analyzed by flow cyometry. The CXCR4 expression was reported as relative mean fluorescent intensity (RMFI) compared to isotype control. We then performed cell cycle analysis of G2 cells treated with cytarabine or bortezomib for 18 hours. All cells were treated with BrdU 1 hour prior to harvest, then stained with APC-conjugated anti-BrdU antibody and analyzed by flow cytometry. Results: Incubation of G2 cells with HS-5 protected them from apoptosis induced by cytarabine or doxorubicin but not bortezomib. The apoptosis rate for cytarabine treated cells was 55±0.3% without HS-5 vs. 15%±0.8 with HS-5(p<0.0001). The apoptosis rate of doxorubicin treated cells was 23±0.6% without HS-5 vs. 4.2±0.8% with HS-5 (p<0.0001). In the case of bortezomib, the apoptosis rate was 67±0.6% without HS-5 vs. 71±1.2% with HS-5. Similar results were observed with the BV-173 ALL cell line and with the use of HS-27a stromal cell line. We noted down-regulation of CXCR4 expression when G2 cells were co-cultured with stromal cells or after bortezomib treatment. In the absence of stromal cells, the CXCR4 RMFI was 40±3 in untreated cells vs. 16±0.4 in bortezomib treated cells (P=0.0015). In the presence of stromal cells CXCR4 RMFI 15±0.7% in untreated cells vs. 5±0.2% in bortezomib treated cells (P=0.0002). In cell cycle analysis, we found only 1.03±0.2% of cells treated with cytarabine were in S phase compared to 10.05±0.7% when cells were treated with bortezomib (P=0.0003). Conclusion: Bortezomib can overcome the stromal cell-mediated protection of human G2 ALL cells. This effect may be, in part, mediated by in the decreased surface expression of CXCR4 shown by others to mediate leukemia-stroma interaction and chemoprotection. In contrast to cytarabine which selectively kills cells in S phase, bortezomib induced killing of ALL cells regardless of cell cycle status. Future studies will use of in vivo mouse models of ALL to test the effects of bortezomib alone or in combination with chemotherapy on survival. Disclosures: DiPersio: genzyme: Honoraria.

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