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Alba G, Martínez R, Postigo-Corrales F, López S, Santa-María C, Jiménez J, Cahuana GM, Soria B, Bedoya FJ, Tejedo JR. AICAR Stimulates the Pluripotency Transcriptional Complex in Embryonic Stem Cells Mediated by PI3K, GSK3β, and β-Catenin. ACS OMEGA 2020; 5:20270-20282. [PMID: 32832780 PMCID: PMC7439381 DOI: 10.1021/acsomega.0c02137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 07/23/2020] [Indexed: 05/03/2023]
Abstract
Pluripotent stem cells maintain the property of self-renewal and differentiate into all cell types under clear environments. Though the gene regulatory mechanism for pluripotency has been investigated in recent years, it is still not completely understood. Here, we show several signaling pathways involved in the maintenance of pluripotency. To investigate whether AMPK is involved in maintaining the pluripotency in mouse embryonic stem cells (mESCs) and elucidating the possible molecular mechanisms, implicated D3 and R1/E mESC lines were used in this study. Cells were cultured in the absence or presence of LIF and treated with 1 mM and 0.5 mM 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR), 2 mM metformin, compound C, and the PI3K inhibitor LY294002 for 24, 72, and 120 h. The levels of Nanog, Oct3/4, and REX1 and Brachyury, Notch2, and Gata4 mRNAs and Nanog or OCT3/4 protein levels were analyzed. Alkaline phosphatase and the cellular cycle were determined. The pGSK3β, GSK3β, p-β-catenin, and β-catenin protein levels were also investigated. We found that AMPK activators such as AICAR and metformin increase mRNA expression of pluripotency markers and decrease mRNA expression of differentiation markers in R1/E and D3 ES cells. AICAR increases phosphatase activity and arrests the cellular cycle in the G1 phase in these cells. We describe that AICAR effects were mediated by AMPK activation using a chemical inhibitor or by silencing this gene. AICAR effects were also mediated by PI3K, GSK3β, and β-catenin in R1/E ES cells. According to our findings, we provide a mechanism by which AICAR increases and maintains a pluripotency state through enhanced Nanog expression, involving AMPK/PI3K and p-GSK3β Ser21/9 pathways backing up the AICAR function as a potential target for this drug controlling pluripotency. The highlights of this study are that AICAR (5-aminoimidazole-4-carboxamied-1-b-riboside), an AMP protein kinase (AMPK) activator, blocks the ESC differentiation and AMPK is a key enzyme for pluripotency and shows valuable data to clarify the molecular pluripotency mechanism.
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Affiliation(s)
- Gonzalo Alba
- Department
of Medical Biochemistry and Molecular Biology, Universidad de Sevilla, Seville 41009, Spain
- . Telephone: +34-955421044. Fax: +34-954907048
| | - Raquel Martínez
- Department
of Regeneration and Cell Therapy, Andalusian Center for Molecular
Biology and Regenerative Medicine-CABIMER, Universidad Pablo de Olavide-University of Seville-CSIC, Seville 41013, Spain
| | - Fátima Postigo-Corrales
- Department
of Regeneration and Cell Therapy, Andalusian Center for Molecular
Biology and Regenerative Medicine-CABIMER, Universidad Pablo de Olavide-University of Seville-CSIC, Seville 41013, Spain
| | - Soledad López
- Department
of Medical Biochemistry and Molecular Biology, Universidad de Sevilla, Seville 41009, Spain
| | - Consuelo Santa-María
- Department
of Biochemistry and Molecular Biology, Universidad
de Sevilla, Seville 41009, Spain
| | - Juan Jiménez
- Department
of Medical Biochemistry and Molecular Biology, Universidad de Sevilla, Seville 41009, Spain
| | - Gladys M. Cahuana
- Department
of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, Seville 41013, Spain
- Biomedical
Research Network for Diabetes and Related Metabolic Diseases-CIBERDEM,
Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Bernat Soria
- Department
of Regeneration and Cell Therapy, Andalusian Center for Molecular
Biology and Regenerative Medicine-CABIMER, Universidad Pablo de Olavide-University of Seville-CSIC, Seville 41013, Spain
- Biomedical
Research Network for Diabetes and Related Metabolic Diseases-CIBERDEM,
Instituto de Salud Carlos III, Madrid 28029, Spain
- Cell
Therapy
Network, Madrid (RED-TERCEL), Instituto
de Salud Carlos III, Madrid 28029, Spain
- Universidad
Miguel Hernández, Alicante 03550, Spain
| | - Francisco J. Bedoya
- Department
of Regeneration and Cell Therapy, Andalusian Center for Molecular
Biology and Regenerative Medicine-CABIMER, Universidad Pablo de Olavide-University of Seville-CSIC, Seville 41013, Spain
- Department
of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, Seville 41013, Spain
- Biomedical
Research Network for Diabetes and Related Metabolic Diseases-CIBERDEM,
Instituto de Salud Carlos III, Madrid 28029, Spain
- Cell
Therapy
Network, Madrid (RED-TERCEL), Instituto
de Salud Carlos III, Madrid 28029, Spain
| | - Juan R. Tejedo
- Department
of Regeneration and Cell Therapy, Andalusian Center for Molecular
Biology and Regenerative Medicine-CABIMER, Universidad Pablo de Olavide-University of Seville-CSIC, Seville 41013, Spain
- Department
of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, Seville 41013, Spain
- Biomedical
Research Network for Diabetes and Related Metabolic Diseases-CIBERDEM,
Instituto de Salud Carlos III, Madrid 28029, Spain
- Cell
Therapy
Network, Madrid (RED-TERCEL), Instituto
de Salud Carlos III, Madrid 28029, Spain
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CHIR99021 enhances Klf4 Expression through β-Catenin Signaling and miR-7a Regulation in J1 Mouse Embryonic Stem Cells. PLoS One 2016; 11:e0150936. [PMID: 26938105 PMCID: PMC4777400 DOI: 10.1371/journal.pone.0150936] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 02/21/2016] [Indexed: 11/19/2022] Open
Abstract
Understanding the mechanisms that regulate pluripotency of embryonic stem cells (ESCs) is important to ensure their safe clinical use. CHIR99021 (CHIR)-induced activation of Wnt/β-catenin signaling promotes self-renewal in mouse ESCs (mESCs). β-catenin functions individually or cooperates with transcription factors to activate stemness factors such as c-Myc, Esrrb, Pou5f1, and Nanog. However the relationship between the core pluripotent factor, Kruppel-like factor 4 (also known as GKLF or EZF) and Wnt/β-catenin signaling, remains ambiguous in J1 mESCs. DNA microarray analysis revealed that CHIR-treatment promoted pluripotency-maintaining transcription factors and repressed germ layer specification markers. CHIR also promoted genes related to the development of extracellular regions and the plasma membrane to maintain pluripotency of J1 mESCs. Among the CHIR-regulated genes, Klf4 has not been reported previously. We identified a novel cis element in the Klf4 gene that was activated by β-catenin in J1 mESCs. We determined that β-catenin interacted with this cis element, identifying Klf4 as a β-catenin target gene in this context. Moreover, several microRNAs that targeted the 3′-UTR of Klf4 mRNA were identified, with miR-7a being down-regulated by CHIR in a β-catenin-independent manner in J1 mESCs. These data collectively suggest that CHIR enhances Klf4 expression by repressing miR-7a expression or canonical Wnt pathway activation.
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