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Chen G, Yin S, Zeng H, Li H, Wan X. Regulation of Embryonic Stem Cell Self-Renewal. LIFE (BASEL, SWITZERLAND) 2022; 12:life12081151. [PMID: 36013330 PMCID: PMC9410528 DOI: 10.3390/life12081151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/12/2022] [Accepted: 07/21/2022] [Indexed: 11/16/2022]
Abstract
Embryonic stem cells (ESCs) are a type of cells capable of self-renewal and multi-directional differentiation. The self-renewal of ESCs is regulated by factors including signaling pathway proteins, transcription factors, epigenetic regulators, cytokines, and small molecular compounds. Similarly, non-coding RNAs, small RNAs, and microRNAs (miRNAs) also play an important role in the process. Functionally, the core transcription factors interact with helper transcription factors to activate the expression of genes that contribute to maintaining pluripotency, while suppressing the expression of differentiation-related genes. Additionally, cytokines such as leukemia suppressor factor (LIF) stimulate downstream signaling pathways and promote self-renewal of ESCs. Particularly, LIF binds to its receptor (LIFR/gp130) to trigger the downstream Jak-Stat3 signaling pathway. BMP4 activates the downstream pathway and acts in combination with Jak-Stat3 to promote pluripotency of ESCs in the absence of serum. In addition, activation of the Wnt-FDZ signaling pathway has been observed to facilitate the self-renewal of ESCs. Small molecule modulator proteins of the pathway mentioned above are widely used in in vitro culture of stem cells. Multiple epigenetic regulators are involved in the maintenance of ESCs self-renewal, making the epigenetic status of ESCs a crucial factor in this process. Similarly, non-coding RNAs and cellular energetics have been described to promote the maintenance of the ESC's self-renewal. These factors regulate the self-renewal and differentiation of ESCs by forming signaling networks. This review focused on the role of major transcription factors, signaling pathways, small molecular compounds, epigenetic regulators, non-coding RNAs, and cellular energetics in ESC's self-renewal.
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Affiliation(s)
- Guofang Chen
- Shanghai Key Laboratory of Maternal Fetal Medicine, Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai 201204, China;
- Correspondence: (G.C.); (H.L.); (X.W.); Tel./Fax: +86-021-20261000 (ext. 1379) (G.C.)
| | - Shasha Yin
- Shanghai Key Laboratory of Maternal Fetal Medicine, Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai 201204, China;
| | - Hongliang Zeng
- Institute of Chinese Materia Medica, Hunan Academy of Chinese Medicine, Changsha 410013, China;
| | - Haisen Li
- School of Medicine, Wayne State University, Detroit, MI 48201, USA
- Correspondence: (G.C.); (H.L.); (X.W.); Tel./Fax: +86-021-20261000 (ext. 1379) (G.C.)
| | - Xiaoping Wan
- Shanghai Key Laboratory of Maternal Fetal Medicine, Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai 201204, China;
- Correspondence: (G.C.); (H.L.); (X.W.); Tel./Fax: +86-021-20261000 (ext. 1379) (G.C.)
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Oliveira T, Costa I, Marinho V, Carvalho V, Uchôa K, Ayres C, Teixeira S, Vasconcelos DFP. Human foreskin fibroblasts: from waste bag to important biomedical applications. JOURNAL OF CLINICAL UROLOGY 2018. [DOI: 10.1177/2051415818761526] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Circumcision is one of the most performed surgical procedures worldwide, and it is estimated that one in three men worldwide is circumcised, which makes the preputial skin removed after surgery an abundant material for possible applications. In particular, it is possible efficiently to isolate the cells of the foreskin, with fibroblasts being the most abundant cells of the dermis and the most used in biomedical research. This work aimed to review the knowledge and obtain a broad view of the main applications of human foreskin fibroblast cell culture. A literature search was conducted, including clinical trials, preclinical basic research studies, reviews and experimental studies. Several medical and laboratory applications of human foreskin fibroblast cell culture have been described, especially when it comes to the use of human foreskin fibroblasts as feeder cells for the cultivation of human embryonic stem cells, in addition to co-culture with other cell types. The culture of foreskin fibroblasts has also been used to: obtain induced pluripotent stem cells; the diagnosis of Clostridium difficile; to test the toxicity and effect of substances on normal cells, especially the toxicity of possible antineoplastic drugs; in viral culture, mainly of the human cytomegalovirus, study of the pathogenesis of other microorganisms; varied studies of cellular physiology and cellular interactions. Fibroblasts are important for cell models for varied application cultures, demonstrating how the preputial material can be reused, making possible new applications. Level of evidence: Not applicable for this multicentre audit.
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Affiliation(s)
- Thomaz Oliveira
- Genetics and Molecular Biology Laboratory, Federal University of Piauí (UFPI), Brazil
- Brain Mapping and Plasticity Laboratory, Federal University of Piauí (UFPI), Brazil
- Biomedical Sciences, Federal University of Piauí (UFPI), Brazil
| | - Ilana Costa
- Biomedical Sciences, Federal University of Piauí (UFPI), Brazil
| | - Victor Marinho
- Genetics and Molecular Biology Laboratory, Federal University of Piauí (UFPI), Brazil
- Brain Mapping and Plasticity Laboratory, Federal University of Piauí (UFPI), Brazil
- Biomedical Sciences, Federal University of Piauí (UFPI), Brazil
| | - Valécia Carvalho
- Brain Mapping and Plasticity Laboratory, Federal University of Piauí (UFPI), Brazil
- Biomedical Sciences, Federal University of Piauí (UFPI), Brazil
| | - Karla Uchôa
- Genetics and Molecular Biology Laboratory, Federal University of Piauí (UFPI), Brazil
- Biomedical Sciences, Federal University of Piauí (UFPI), Brazil
| | - Carla Ayres
- Brain Mapping and Plasticity Laboratory, Federal University of Piauí (UFPI), Brazil
| | - Silmar Teixeira
- Brain Mapping and Plasticity Laboratory, Federal University of Piauí (UFPI), Brazil
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Zhang D, Mai Q, Li T, Huang J, Ding C, Jia M, Zhou C, Xu Y. Comparison of a xeno-free and serum-free culture system for human embryonic stem cells with conventional culture systems. Stem Cell Res Ther 2016; 7:101. [PMID: 27474011 PMCID: PMC4967296 DOI: 10.1186/s13287-016-0347-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Revised: 05/14/2016] [Accepted: 06/10/2016] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Elimination of all animal components during derivation and long-term culture of human embryonic stem cells (hESCs) is necessary for future applications of hESCs in clinical cell therapy. METHODS In this study, we established the culture system of xeno-free human foreskin fibroblast feeders (XF-HFF) in combination with chemically defined medium (CDM). XF-HFF/CDM was compared with several conventional culture systems. The hESCs cultured in different media were further characterized through karyotype analysis, pluripotency gene expression, and cell differentiation ability. RESULTS The hESCs in the XF-HFF/CDM maintained their characteristics including typical morphology and stable karyotype. In addition, hESCs were characterized by fluorescent immunostaining of pluripotent markers and teratoma formation in vivo. RT-PCR analysis shown that the stem cell markers OCT3/4, hTERT, SOX2, and Nanog were present in the cell line hESC-1 grown on XF-HFF/CDM. Furthermore, the results of cell growth and expression of bFGF, Oct-4, and hTERT indicated that XF-HFF/CDM had better performance than human serum-matrix/CDM and XF-HFF/human serum. CONCLUSION The comparison of different xeno-free culture conditions will facilitate clarifying the key features of self-renewal, pluripotency, and derivation and will shed light on clinic applications of hESCs.
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Affiliation(s)
- Dan Zhang
- Reproductive Medicine Center, the First Affiliated Hospital of Sun Yat-sen University, 58 Zhongshan Road II, Guangzhou, Guangdong, 510080, People's Republic of China
| | - Qingyun Mai
- Reproductive Medicine Center, the First Affiliated Hospital of Sun Yat-sen University, 58 Zhongshan Road II, Guangzhou, Guangdong, 510080, People's Republic of China
| | - Tao Li
- Reproductive Medicine Center, the First Affiliated Hospital of Sun Yat-sen University, 58 Zhongshan Road II, Guangzhou, Guangdong, 510080, People's Republic of China
| | - Jia Huang
- Reproductive Medicine Center, the First Affiliated Hospital of Sun Yat-sen University, 58 Zhongshan Road II, Guangzhou, Guangdong, 510080, People's Republic of China
| | - Chenhui Ding
- Reproductive Medicine Center, the First Affiliated Hospital of Sun Yat-sen University, 58 Zhongshan Road II, Guangzhou, Guangdong, 510080, People's Republic of China
| | - Mengxi Jia
- Reproductive Medicine Center, the First Affiliated Hospital of Sun Yat-sen University, 58 Zhongshan Road II, Guangzhou, Guangdong, 510080, People's Republic of China
| | - Canquan Zhou
- Reproductive Medicine Center, the First Affiliated Hospital of Sun Yat-sen University, 58 Zhongshan Road II, Guangzhou, Guangdong, 510080, People's Republic of China.
| | - Yanwen Xu
- Reproductive Medicine Center, the First Affiliated Hospital of Sun Yat-sen University, 58 Zhongshan Road II, Guangzhou, Guangdong, 510080, People's Republic of China.
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Wang Y, Li Y, Song L, Li Y, Jiang S, Zhang S. The transplantation of Akt-overexpressing amniotic fluid-derived mesenchymal stem cells protects the heart against ischemia-reperfusion injury in rabbits. Mol Med Rep 2016; 14:234-42. [PMID: 27151366 PMCID: PMC4918560 DOI: 10.3892/mmr.2016.5212] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 04/22/2016] [Indexed: 12/24/2022] Open
Abstract
Amniotic fluid-derived mesenchymal stem cells (AFMSCs) are an attractive cell source for applications in regenerative medicine, due to characteristics such as proliferative capacity and multipotency. In addition, Akt, a serine‑threonine kinase, maintains stem cells by promoting viability and proliferation. Whether the transplantation of Akt-overexpressing AFMSCs protects the heart against ischemia‑reperfusion (I/R) injury has yet to be elucidated. Accordingly, the Akt gene was overexpressed in AFMSCs using lentiviral transduction, and Akt‑AFMSCs were transplanted into the ischemic myocardium of rabbits prior to reperfusion. Any protective effects resulting from this procedure were subsequently sought after three weeks later. A histological examination revealed that there was a decrease in intramyocardial inflammation and ultrastructural damage, and an increase in capillary density and in the levels of GATA binding protein 4, connexin 43 and cardiac troponin T in the Akt‑AFMSC group compared with the control group. A significant decrease in cardiomyocyte apoptosis, accompanying an increase in phosphorylated Akt and B‑cell lymphoma 2 (Bcl-2) and a decrease in caspase‑3, was also observed. Furthermore, the left ventricular function was markedly augmented in the Akt‑AFMSC group compared with the control group. These observations suggested that the protective effect of AFMSCs may be due to the delivery of secreted cytokines, promotion of neoangiogenesis, prevention of cardiomyocyte apoptosis, transdifferentiation into cardiomyocytes and promotion of the viability of AFMSCs, which are assisted by Akt gene modification. Taken together, the results of the present study have indicated that transplantation of Akt-AFMSCs is able to alleviate myocardial I/R injury and improve cardiac function.
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Affiliation(s)
- Yan Wang
- Department of Geriatrics, Xinhua Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200092, P.R. China
| | - Yigang Li
- Department of Cardiovascular Diseases, Xinhua Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200092, P.R. China
| | - Lei Song
- Department of Cardiovascular Diseases, Xinhua Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200092, P.R. China
| | - Yanyan Li
- Department of Cardiovascular Diseases, Xinhua Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200092, P.R. China
| | - Shan Jiang
- Department of Cardiovascular Diseases, Xinhua Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200092, P.R. China
| | - Song Zhang
- Department of Cardiovascular Diseases, Xinhua Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200092, P.R. China
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5
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Chilmonczyk Z, Bojarski AJ, Pilc A, Sylte I. Functional Selectivity and Antidepressant Activity of Serotonin 1A Receptor Ligands. Int J Mol Sci 2015; 16:18474-506. [PMID: 26262615 PMCID: PMC4581256 DOI: 10.3390/ijms160818474] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 07/29/2015] [Accepted: 07/31/2015] [Indexed: 01/11/2023] Open
Abstract
Serotonin (5-HT) is a monoamine neurotransmitter that plays an important role in physiological functions. 5-HT has been implicated in sleep, feeding, sexual behavior, temperature regulation, pain, and cognition as well as in pathological states including disorders connected to mood, anxiety, psychosis and pain. 5-HT1A receptors have for a long time been considered as an interesting target for the action of antidepressant drugs. It was postulated that postsynaptic 5-HT1A agonists could form a new class of antidepressant drugs, and mixed 5-HT1A receptor ligands/serotonin transporter (SERT) inhibitors seem to possess an interesting pharmacological profile. It should, however, be noted that 5-HT1A receptors can activate several different biochemical pathways and signal through both G protein-dependent and G protein-independent pathways. The variables that affect the multiplicity of 5-HT1A receptor signaling pathways would thus result from the summation of effects specific to the host cell milieu. Moreover, receptor trafficking appears different at pre- and postsynaptic sites. It should also be noted that the 5-HT1A receptor cooperates with other signal transduction systems (like the 5-HT1B or 5-HT2A/2B/2C receptors, the GABAergic and the glutaminergic systems), which also contribute to its antidepressant and/or anxiolytic activity. Thus identifying brain specific molecular targets for 5-HT1A receptor ligands may result in a better targeting, raising a hope for more effective medicines for various pathologies.
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Affiliation(s)
- Zdzisław Chilmonczyk
- National Medicines Institute, Chełmska 30/34, 00-725 Warszawa, Poland.
- Institute of Nursing and Health Sciences, University of Rzeszów, W. Kopisto 2A, 35-310 Rzeszów, Poland.
| | - Andrzej Jacek Bojarski
- Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, 31-343 Kraków, Poland.
| | - Andrzej Pilc
- Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, 31-343 Kraków, Poland.
| | - Ingebrigt Sylte
- Faculty of Health Sciences, University of Tromsø-The Arctic University of Norway, No-9037 Tromsø, Norway.
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6
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Ishizuka T, Watanabe Y. [Involvement of cell membrane receptors on proliferation and differentiation of pluripotent stem cells]. Nihon Yakurigaku Zasshi 2014; 144:13-6. [PMID: 25007806 DOI: 10.1254/fpj.144.13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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7
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Hu JG, Wu XJ, Feng YF, Xi GM, Deng LX, Wang ZH, Wang R, Shen L, Zhou JS, Lü HZ. The molecular events involved in oligodendrocyte precursor cell proliferation induced by the conditioned medium from b104 neuroblastoma cells. Neurochem Res 2013; 38:601-9. [PMID: 23283697 DOI: 10.1007/s11064-012-0957-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 11/28/2012] [Accepted: 12/19/2012] [Indexed: 11/29/2022]
Abstract
The conditioned medium from B104 neuroblastoma cells (B104CM) induces proliferation of oligodendrocyte progenitor cells (OPCs) in vitro. However, the molecular events that occur during B104CM-induced proliferation of OPCs has not been well clarified. In the present study, using OPCs immunopanned from embryonic day 14 Sprague-Dawley rat spinal cords, we explored the activation of several signaling pathways and the expression of several important immediate early genes (IEGs) and cyclins in OPCs in response to B104CM. We found that B104CM can induce OPC proliferation through the activation of the extracellular signal-regulated kinases 1 and 2 (Erk1/2), but not PI3K or p38 MAPK signaling pathways in vitro. The IEGs involved in B104CM-induced OPC proliferation include c-fos, c-jun and Id2, but not c-myc, fyn, or p21. The cyclins D1, D2 and E are also involved in B104CM-stimulated proliferation of OPCs. The activation of Erk results in subsequent expression of IEGs (such as c-fos, c-jun and Id-2) and cyclins (including cyclin D1, D2 and E), which play key roles in cell cycle initiation and OPC proliferation. Collectively, these results suggest that the phosphorylation of Erk1/2 is an important molecular event during OPC proliferation induced by B104CM.
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Affiliation(s)
- Jian-Guo Hu
- Department of Clinical Laboratory Science, The First Affiliated Hospital of Bengbu Medical College, 287 Chang Huai Road, Bengbu, 233004, People's Republic of China
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8
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Wang Y, Xu C, Wang H, Liu J, Hui S, Li N, Liu F, Li J. Efficient derivation of human embryonic stem cell lines from discarded embryos through increases in the concentration of basic fibroblast growth factor. Hum Cell 2012; 25:16-23. [PMID: 22287285 DOI: 10.1007/s13577-011-0039-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Accepted: 12/26/2011] [Indexed: 01/20/2023]
Abstract
We describe the derivation and characterization of three novel human embryonic stem (hES) cell lines (YT1, YT2, YT3). One hES line (YT1) was obtained from six discarded blastocysts in a culture medium supplemented with 12 ng/ml basic fibroblast growth factor (bFGF), and two lines (YT2,YT3)were obtained from three discarded blastocysts in the same medium but supplemented with 16 ng/ml bFGF. These cell lines were derived by partial or whole embryo culture followed by further expansion after manual dissection of the passaged cells. These cells were passaged continuously for more than 6 or 8 months and possessed all of the typical features of pluripotent hES cell lines, such as typical morphological characteristics and the expression of hES-specific markers (TRA-1-60, TRA-1-81, SSEA-4, SSEA-3, alkaline phosphatase, Oct4, Nanog) and pluripotency-related genes (Oct4, Nanog, TDGF1, Sox2, EBAF, Thy-1, FGF4, Rex1). The lines maintained normal karyotypes after long-term cultivation. The karyotype of YT1 and YT3 was 46,XX, and that of YT2 was 46, XY. Pluripotency was confirmed by in vitro and in vivo differentiation, and genetic identity was demonstrated by DNA fingerprinting.Our results indicate that higher concentrations of bFGF at the early culture stage support efficient the hES cell derivation.
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Affiliation(s)
- Yanwei Wang
- Shandong Research Center of Stem Cell Engineering, Yantai Yuhuangding Hospital, Shandong Province, People's Republic of China
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9
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Huang W, Zhao Y, Zhu X, Cai Z, Wang S, Yao S, Qi Z, Xie P. Fluoxetine upregulates phosphorylated-AKT and phosphorylated-ERK1/2 proteins in neural stem cells: evidence for a crosstalk between AKT and ERK1/2 pathways. J Mol Neurosci 2012; 49:244-9. [PMID: 22674052 DOI: 10.1007/s12031-012-9822-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Accepted: 05/24/2012] [Indexed: 01/17/2023]
Abstract
Fluoxetine is a widely used antidepressant drug which inhibits the reuptake of serotonin in the central nervous system (CNS). Recent studies have shown that fluoxetine can promote neurogenesis and improve the survival rate of neurons. However, whether fluoxetine modulates the neuroprotection of neural stem cells (NSCs) needs to be elucidated. In this study, we demonstrated that 50 μM fluoxetine significantly upregulated expression of the phosphorylated-AKT and ERK1/2 proteins in NSCs derived from rats. Besides, expression of phosphorylated-AKT and phosphorylated-ERK1/2 in fluoxetine-treated NSCs was effectively blocked (P<0.05) by both PI3-K inhibitor (LY294002) and MEK inhibitor (PD98059). It was, therefore, concluded that the crosstalk between PI3K/AKT and MAPK/ERK pathways involved AKT and ERK1/2 phosphorylation by fluoxetine treatment. This study points to a novel role of fluoxetine in neuroprotection as an antidepressant drug and also unravels the crosstalk mechanism between the two signaling pathways.
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Affiliation(s)
- Wen Huang
- Department of Neurology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
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10
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Expression and function of myelin-associated proteins and their common receptor NgR on oligodendrocyte progenitor cells. Brain Res 2012; 1437:1-15. [DOI: 10.1016/j.brainres.2011.12.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2011] [Revised: 12/01/2011] [Accepted: 12/03/2011] [Indexed: 11/30/2022]
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11
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Fu X, Xu Y. Self-renewal and scalability of human embryonic stem cells for human therapy. Regen Med 2011; 6:327-34. [PMID: 21548738 DOI: 10.2217/rme.11.18] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Human embryonic stem cells (hESCs) can undergo unlimited self-renewal and retain the pluripotency to differentiate into all cell types in the body. Therefore, as a renewable source of various cell types, hESCs hold great promise for human cell replacement therapy. While significant progress has been made in establishing the culture conditions for the long-term self-renewal of hESCs, several challenges remain to be overcome for the clinical application of hESCs. One such challenge is to develop strategies to scale-up the production of clinic-grade hESCs in xeno-free and chemically defined medium without inducing genomic instability. To achieve this goal, it is critical to elucidate the molecular pathways required to maintain the self-renewal, survival and genomic stability of hESCs. This article describes recent progress in addressing this challenge and discusses the strategies to improve the scalability of the production of hESCs by inhibiting their apoptosis.
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Affiliation(s)
- Xuemei Fu
- Chengdu Women's & Children's Central Hospital, Chengdu, Sichuan, China
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12
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Hu JG, Wang YX, Wang HJ, Bao MS, Wang ZH, Ge X, Wang FC, Zhou JS, Lü HZ. PDGF-AA mediates B104CM-induced oligodendrocyte precursor cell differentiation of embryonic neural stem cells through Erk, PI3K, and p38 signaling. J Mol Neurosci 2011; 46:644-53. [PMID: 21953009 DOI: 10.1007/s12031-011-9652-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Accepted: 09/15/2011] [Indexed: 11/25/2022]
Abstract
The conditioned medium from B104 neuroblastoma cells (B104CM) induces neural stem cells (NSCs) to differentiate into OPCs in vitro, which indicates that certain factor(s) contained within the B104CM must give instructional signals that direct OPC differentiation of NSCs. However, the OPC-inductive factor(s) present within the B104CM has not been well identified yet. Platelet-derived growth factor AA (PDGF-AA) was not only known to be a potent mitogen for OPC proliferation but also to act as a regulator of oligodendrocyte differentiation from multipotent embryonic NSCs. This raises the possibility that B104CM induces OPC differentiation of NSCs through secretion of PDGF-AA. In the present study, we detected the expression of PDGF-AA mRNA in B104 cells and the high level of PDGF-AA protein in B104CM. Most importantly, B104CM-induced OPC differentiation of NSCs could be completely blocked by AG1295, a specific inhibitor of PDGFR signal pathway, suggesting that the PDGF-AA in B104CM is the key factor that induces NSCs to differentiate into OPCs. Moreover, such B104CM-induced OPC differentiation appears to be mediated by the extracellular signal-regulated kinases 1 and 2 (Erk1/2), phosphatidylinositol-3 kinase (PI3K), and p38 signal pathway because B104CM elicited the activation of Erk1/2, PI3K, and p38, which could be markedly blocked by U0126, LY294002, and SB203580, several specific inhibitors of these signal pathway, respectively. These inhibitors also abolished OPC differentiation of NSCs completely. Together our study suggests that PDGF-AA contained in B104CM is the key regulating molecule that instructs OPC differentiation from embryonic NSCs through the activation of Erk, PI3K, and p38 signal pathway in vitro.
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Affiliation(s)
- Jian-Guo Hu
- Department of Clinical Laboratory Science, The First Affiliated Hospital of Bengbu Medical College, Bengbu, 233004, People's Republic of China
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13
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Neal CL, Xu J, Li P, Mori S, Yang J, Neal NN, Zhou X, Wyszomierski SL, Yu D. Overexpression of 14-3-3ζ in cancer cells activates PI3K via binding the p85 regulatory subunit. Oncogene 2011; 31:897-906. [PMID: 21743495 PMCID: PMC3193867 DOI: 10.1038/onc.2011.284] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The ubiquitously expressed 14-3-3 proteins regulate many pathways involved in transformation. Previously, we found that 14-3-3ζ overexpression increased Akt phosphorylation in human mammary epithelial cells. Here, we investigated the clinical relevance and molecular mechanism of 14-3-3ζ overexpression-mediated Akt phosphorylation and the potential impact on breast cancer progression. We found that 14-3-3ζ overexpression was significantly (P = 0.005) associated with increased Akt phosphorylation in human breast tumors. Additionally, 14-3-3ζ overexpression combined with strong Akt phosphorylation was significantly (P=0.01) associated with increased cancer recurrence in patients. In contrast, knockdown of 14-3-3ζ expression by siRNA in cancer cell lines and tumor xenografts reduced Akt phosphorylation. Furthermore, 14-3-3ζ enhanced Akt phosphorylation through activation of PI3K. Mechanistically, 14-3-3ζ bound to the p85 regulatory subunit of PI3K and increased PI3K translocation to the cell membrane. A single 14-3-3 binding motif encompassing serine 83 on p85 is largely responsible for 14-3-3ζ-mediated p85 binding and PI3K/Akt activation. Mutation of serine 83 to alanine on p85 inhibited 14-3-3ζ binding to the p85 subunit of PI3K, reduced PI3K membrane localization and activation, impeded anchorage independent growth and enhanced stress induced apoptosis. These findings revealed a novel mechanism by which 14-3-3ζ overexpression activates PI3K, a key node in the mitogenic signaling network known to promote malignancies in many cell types.
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Affiliation(s)
- C L Neal
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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14
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Podo F, Canevari S, Canese R, Pisanu ME, Ricci A, Iorio E. MR evaluation of response to targeted treatment in cancer cells. NMR IN BIOMEDICINE 2011; 24:648-672. [PMID: 21387442 DOI: 10.1002/nbm.1658] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Revised: 11/22/2010] [Accepted: 11/29/2010] [Indexed: 05/30/2023]
Abstract
The development of molecular technologies, together with progressive sophistication of molecular imaging methods, has allowed the further elucidation of the multiple mutations and dysregulatory effects of pathways leading to oncogenesis. Acting against these pathways by specifically targeted agents represents a major challenge for current research efforts in oncology. As conventional anatomically based pharmacological endpoints may be inadequate to monitor the tumor response to these targeted treatments, the identification and use of more appropriate, noninvasive pharmacodynamic biomarkers appear to be crucial to optimize the design, dosage and schedule of these novel therapeutic approaches. An aberrant choline phospholipid metabolism and enhanced flux of glucose derivatives through glycolysis, which sustain the redirection of mitochondrial ATP to glucose phosphorylation, are two major hallmarks of cancer cells. This review focuses on the changes detected in these pathways by MRS in response to targeted treatments. The progress and limitations of our present understanding of the mechanisms underlying MRS-detected phosphocholine accumulation in cancer cells are discussed in the light of gene and protein expression and the activation of different enzymes involved in phosphatidylcholine biosynthesis and catabolism. Examples of alterations induced in the MRS choline profile of cells exposed to different agents or to tumor environmental factors are presented. Current studies aimed at the identification in cancer cells of MRS-detected pharmacodynamic markers of therapies targeted against specific conditional or constitutive cell receptor stimulation are then reviewed. Finally, the perspectives of present efforts addressed to identify enzymes of the phosphatidylcholine cycle as possible novel targets for anticancer therapy are summarized.
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Affiliation(s)
- Franca Podo
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy.
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15
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Meng G, Liu S, Li X, Krawetz R, Rancourt DE. Extracellular matrix isolated from foreskin fibroblasts supports long-term xeno-free human embryonic stem cell culture. Stem Cells Dev 2010; 19:547-56. [PMID: 19883201 DOI: 10.1089/scd.2009.0303] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Human embryonic stem (hES) cells hold great promise for application of human cell and tissue replacement therapy. However, the overwhelming majority of currently available hES cell lines have been directly or indirectly exposed to materials containing animal-derived components during their derivation, propagation, and cryopreservation. Unlike feeder-based cultures, which require the simultaneous growth of feeder and stem cells, resulting in mixed cell populations, stem cells grown on feeder-free systems are easily separated from the surface, presenting a pure population of cells for downstream applications. In this study, we have developed a novel method to expand hES cells in xeno-free, feeder-free conditions using 2 different matrices derived from xeno-free human foreskin fibroblasts (XF-HFFs). Using XF-HFF-derived extracellular matrix, together with 100 ng/mL recombinant bFGF-supplemented HEScGRO Basal Medium, long-term xeno-free expansion of hES cells is possible. Resulting hES cells were subjected to stringent tests and were found to maintain ES cell features, including morphology, pluripotency, stable karyotype, and expression of cell surface markers, for at least 20 passages. Xeno-free culturing practices are essential for the translation of basic hES cell research into the clinic. Therefore, the method presented in this study demonstrates that hES cells can be cultured in complete xeno-free conditions without the loss of pluripotency and furthermore, without the possibility of contamination from exogenous sources.
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Affiliation(s)
- Guoliang Meng
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Canada
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16
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Sumer H, Liu J, Verma PJ. The use of signalling pathway inhibitors and chromatin modifiers for enhancing pluripotency. Theriogenology 2010; 74:525-33. [PMID: 20615537 DOI: 10.1016/j.theriogenology.2010.05.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 05/24/2010] [Accepted: 05/24/2010] [Indexed: 10/19/2022]
Abstract
Pluripotent embryonic stem cells have been isolated from a limited number of species. The new advances with inducing pluripotency in somatic cells have resulted in the generation of pluripotent stem cells while circumventing the need for embryos. In this review we describe the main signalling pathways involved in maintaining pluripotency and inducing differentiation. Inhibition of the signalling pathways involved in differentiation enhances the derivation and cultivation of pluripotent stem cells. Furthermore, we discuss the use of chromatin modifiers to maintain an open chromatin state which is characteristic of pluripotent stem cells, to facilitate the derivation of pluripotent cell lines.
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Affiliation(s)
- H Sumer
- Centre for Reproduction and Development, Monash Institute of Medical Research, Monash University, 27-31 Wright Street, Clayton VIC 3168, Australia
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17
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Nuclear magnetic resonance detects phosphoinositide 3-kinase/Akt-independent traits common to pluripotent murine embryonic stem cells and their malignant counterparts. Neoplasia 2010; 11:1301-8. [PMID: 20019838 DOI: 10.1593/neo.09850] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Revised: 08/10/2009] [Accepted: 08/10/2009] [Indexed: 12/30/2022] Open
Abstract
Pluripotent embryonic stem (ES) cells, a potential source of somatic precursors for cell therapies, cause tumors after transplantation. Studies of mammalian carcinogenesis using nuclear magnetic resonance (NMR) spectroscopy have revealed changes in the choline region, particularly increased phosphocholine (PCho) content. High PCho levels in murine ES (mES) cells have recently been attributed to cell pluripotency. The phosphoinositide 3-kinase (PI3K)/Akt pathway has been implicated in tumor-like properties of mES cells. This study aimed to examine a potential link between the metabolic profile associated with choline metabolism of pluripotent mES cells and PI3K/Akt signaling. We used mES (ES-D3) and murine embryonal carcinoma cells (EC-F9) and compared the metabolic profiles of 1) pluripotent mES (ESD0), 2) differentiated mES (ESD14), and 3) pluripotent F9 cells. Involvement of the PI3K/Akt pathway was assessed using LY294002, a selective PI3K inhibitor. Metabolic profiles were characterized in the extracted polar fraction by (1)H NMR spectroscopy. Similarities were found between the levels of choline phospholipid metabolites (PCho/total choline and PCho/glycerophosphocholine [GPCho]) in ESD0 and F9 cell spectra and a greater-than five-fold decrease of the PCho/GPCho ratio associated with mES cell differentiation. LY294002 caused no significant change in relative PCho levels but led to a greater-than two-fold increase in PCho/GPCho ratios. These results suggest that the PCho/GPCho ratio is a metabolic trait shared by pluripotent and malignant cells and that PI3K does not underlie its development. It is likely that the signature identified here in a mouse model may be relevant for safe therapeutic applications of human ES cells.
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18
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Comparative Analysis of Five Different Homologous Feeder Cell Lines in the Ability to Support Rhesus Embryonic Stem Cells. Zool Res 2010. [DOI: 10.3724/sp.j.1141.2009..04345] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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19
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Qiu L, Zhang L, Zhu L, Yang D, Li Z, Qin K, Mi X. PI3K/Akt mediates expression of TNF-alpha mRNA and activation of NF-kappaB in calyculin A-treated primary osteoblasts. Oral Dis 2009; 14:727-33. [PMID: 19193202 DOI: 10.1111/j.1601-0825.2008.01490.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE The effect of calyculin A (CA), a serine/threonine protein phosphatase inhibitor, on tumor necrosis factor-alpha (TNF-alpha) in primary osteoblasts was investigated to determine whether protein phosphatases could affect primary osteoblasts and if so which signaling pathways would be involved. MATERIALS AND METHODS Primary osteoblasts were prepared from newborn rat calvaria. Cells were treated with 1 nM CA for different time periods. The expressions of TNF-alpha and GAPDH mRNA were determined by RT-PCR. Cell extracts were subjected to SDS-PAGE and the activation of Akt and NF-kappaB were analyzed by western blotting. RESULTS Calyculin A-treatment markedly increased the expression of TNF-alpha mRNA and enhanced the phosphorylation level of Akt (Ser473) in these cells. Pretreatment with the PI3K inhibitor LY294002 suppressed the increase in TNF-alpha mRNA expression and the phosphorylation of Akt in response to CA. Western blot analysis showed that CA stimulated the phosphorylation and nuclear translocation of NF-kappaB in primary osteoblasts, and these responses were blocked by pretreatment with LY294002. CONCLUSION Calyculin A elicits activation of PI3K/Akt pathway which leads to expression of TNF-alpha mRNA and activation of NF-kappaB. This NF-kappaB activation involves both phosphorylation and nuclear translocation of NF-kappaB.
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Affiliation(s)
- L Qiu
- Department of Endodontics, China Medical University, Shenyang, China.
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20
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Wu Y, Peng H, Cui M, Whitney NP, Huang Y, Zheng JC. CXCL12 increases human neural progenitor cell proliferation through Akt-1/FOXO3a signaling pathway. J Neurochem 2009; 109:1157-67. [PMID: 19302476 DOI: 10.1111/j.1471-4159.2009.06043.x] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
CXCL12, a ligand for the chemokine receptor CXCR4, is well known in mediating neural progenitor cell (NPC) migration during neural development. However, the effects of CXCL12 on human NPC proliferation and its associated signaling pathways remain unclear. The transcription factor, FOXO3a, a downstream target of Akt-1, is critical for cell cycle control and may also play an important role in regulating NPC proliferation. In this study, we found that CXCL12 promotes human NPC proliferation as determined by the proliferation marker Ki67 and BrdU incorporation. This CXCL12-mediated NPC proliferation was associated with an increase in Akt-1 and FOXO3a phosphorylation in a time- and dose-dependent manner. The CXCR4 antagonist (T140) or inhibitors for G proteins (Pertussis toxin) and phosphoinositide 3-kinase (PI3K) (LY294002) abolished CXCL12-mediated NPC proliferation and phosphorylation of Akt-1 and FOXO3a. The roles of Akt-1 and FOXO3a in CXCL12-mediated NPC proliferation were further investigated by using adenoviral over-expression in NPCs. Over-expression of dominant-negative Akt-1 or wild-type FOXO3a in NPC abrogated CXCL12-mediated proliferation. These data suggest that CXCL12-mediated NPC proliferation is reliant upon the phosphorylation of Akt-1 and FOXO3a and gives insight to an essential role of CXCL12 in neurogenesis. Understanding this mechanism may facilitate the development of novel therapeutic targets for NPC proliferation during neurogenesis.
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Affiliation(s)
- Yumei Wu
- Department of Pharmacology, University of Nebraska Medical Center, Omaha, Nebraska, USA
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21
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Saxena S, Hanwate M, Deb K, Sharma V, Totey S. FGF2 secreting human fibroblast feeder cells: a novel culture system for human embryonic stem cells. Mol Reprod Dev 2008; 75:1523-32. [PMID: 18318041 DOI: 10.1002/mrd.20895] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Human embryonic stem cell (hESC) lines are traditionally derived and maintained on mouse embryonic fibroblasts (MEF) which are xenogeneic and enter senescence rapidly. In view of the clinical implications of hESCs, the use of human fibroblast as feeders has been suggested as a plausible alternative. However, use of fibroblast cells from varying sources leads to culture variations along with the need to add FGF2 in cultures to sustain ES cell pluripotency. In this study we report the derivation of FGF2 expressing germ layer derived fibroblast cells (GLDF) from hESC lines. These feeders could support the pluripotency, karyotypes and proliferation of hESCs with or without FGF2 in prolonged cultures as efficiently as that on MEF. GLDF cells were derived from embryoid bodies and characterized for expression of fibroblast markers by RT-PCR, Immunofluorescence and by flow cytometry for CD marker expression. The expression and secretion of FGF2 was confirmed by RT-PCR, Western blot, and ELISA. The hESC lines cultured on MEF and GLDF were analyzed for various stemness markers. These feeder cells with fibroblast cells like properties maintained the properties of hESCs in prolonged culture over 30 passages. Proliferation and pluripotency of hESCs on GLDF was comparable to that on mouse feeders. Further we discovered that these GLDF cells could secrete FGF2 and maintained pluripotency of hESC cultures even in the absence of supplemental FGF2. To our knowledge, this is the first study reporting a novel hESC culture system which does not warrant FGF2 supplementation, thereby reducing the cost of hESC cultures.
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Affiliation(s)
- Shobhit Saxena
- Manipal Institute of Regenerative Medicine, Bangalore, India
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22
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Abstract
Human embryonic stem cells are pluripotent cells derived from the inner cell mass of preimplantation stage embryos. Their unique potential to give rise to all differentiated cell types has generated great interest in stem cell research and the potential that it may have in developmental biology, medicine and pharmacology. The main focus of stem cell research has been on cell therapy for pathological conditions with no current methods of treatment, such as neurodegenerative diseases, cardiac pathology, retinal dysfunction and lung and liver disease. The overall aim is to develop methods of application either of pure cell populations or of whole tissue parts to the diseased organ under investigation. In the field of pulmonary research, studies using human embryonic stem cells have succeeded in generating enriched cultures of type II pneumocytes in vitro. On account of their potential of indefinite proliferation in vitro, embryonic stem cells could be a source of an unlimited supply of cells available for transplantation and for use in gene therapy. Uncovering the ability to generate such cell types will expand our understanding of biological processes to such a degree that disease understanding and management could change dramatically.
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23
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Meng G, Liu S, Krawetz R, Chan M, Chernos J, Rancourt DE. A Novel Method for Generating Xeno-Free Human Feeder Cells for Human Embryonic Stem Cell Culture. Stem Cells Dev 2008; 17:413-22. [DOI: 10.1089/scd.2007.0236] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Guoliang Meng
- Institute of Maternal & Child Health, University of Calgary Medical School, Calgary, AB, Canada, T2N 4N1
| | - Shiying Liu
- Institute of Maternal & Child Health, University of Calgary Medical School, Calgary, AB, Canada, T2N 4N1
| | - Roman Krawetz
- Institute of Maternal & Child Health, University of Calgary Medical School, Calgary, AB, Canada, T2N 4N1
| | - Michael Chan
- Alberta Children's Hospital, Calgary, Canada T2N 4N1
| | - Judy Chernos
- Alberta Children's Hospital, Calgary, Canada T2N 4N1
| | - Derrick E. Rancourt
- Institute of Maternal & Child Health, University of Calgary Medical School, Calgary, AB, Canada, T2N 4N1
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24
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Mogi M, Walsh K, Iwai M, Horiuchi M. Akt-FOXO3a signaling affects human endothelial progenitor cell differentiation. Hypertens Res 2008; 31:153-9. [PMID: 18360030 DOI: 10.1291/hypres.31.153] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Here we address the effect of Akt signaling on endothelial progenitor cells (EPCs). Human peripheral blood mononuclear cells (PBMCs) were cultured on fibronectin-coated dishes in EPC differentiation medium. PBMCs differentiated in a series of three steps: proliferation for foci formation, tight attachment to the dishes in the early stages of differentiation, and maturation in the late stages. In Western blot analysis, Akt expression was attenuated in the early stages of differentiation and was gradually upregulated during EPC maturation. Forkhead box-containing protein, class O 3a (FOXO3a), an Akt downstream target, was downregulated through phosphorylation in the late stages of EPC differentiation. Adenovirus-mediated overexpression of activated FOXO3a in PBMCs markedly increased the number of cell foci but reduced the number of DiI-acetyl LDL EPCs that appear at later time points. These data suggest that Akt/FOXO3a signaling is an important regulator of EPC maturation.
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Affiliation(s)
- Masaki Mogi
- Department of Molecular Cardiovascular Biology and Pharmacology, Ehime University Graduate School of Medicine, Toon, Japan
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25
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Sussman M. "AKT"ing lessons for stem cells: regulation of cardiac myocyte and progenitor cell proliferation. Trends Cardiovasc Med 2008; 17:235-40. [PMID: 17936205 DOI: 10.1016/j.tcm.2007.08.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Revised: 08/15/2007] [Accepted: 08/23/2007] [Indexed: 12/13/2022]
Abstract
Cardiac development and postnatal growth depend on activation of AKT, but initial strategies to improve myocardial repair using AKT were stymied by undesirable corollary alterations in myocardial structure and function. These unfortunate precedents were based on high-level expression of constitutively activated AKT, predominantly in the cytoplasm of the cell. Based on subsequent studies establishing that activated AKT accumulates in the nucleus, we reasoned that the location of AKT, not simply the activity level, would be a critical determinant of the phenotypic outcome resulting from AKT activation. Using myocardial-specific expression of nuclear-targeted AKT (AKT/nuc), the proliferation of myocardial stem and progenitor cell populations is enhanced, casting new light on the implementation of AKT activity as a molecular interventional approach for treatment of cardiomyopathic damage resulting from acute injury, chronic stress, or the debilitating changes of aging.
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Affiliation(s)
- Mark Sussman
- Department of Biology, SDSU Heart Institute, San Diego State University, San Diego, CA 92182, USA.
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26
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Liu Y, Ji L, Ten Y, Wang Y, Pei X. The molecular mechanism of embryonic stem cell pluripotency and self-renewal. ACTA ACUST UNITED AC 2008; 50:619-23. [PMID: 17879059 DOI: 10.1007/s11427-007-0074-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Accepted: 04/16/2007] [Indexed: 01/09/2023]
Abstract
The self-renewal and pluripotency of embryonic stem cells (ESCs) is regulated by a network, which consists of a series of cell factors in microenviroments, a chain of transcription factors and certain signal conduction pathways. This article reviews recent progress in this field to elucidate the mechanism involved.
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Affiliation(s)
- YuXiao Liu
- Laboratory of Stem Cell Biology, Beijing Institution of Transfusion Medicine, Beijing 100850, China
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27
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Hu JG, Fu SL, Wang YX, Li Y, Jiang XY, Wang XF, Qiu MS, Lu PH, Xu XM. Platelet-derived growth factor-AA mediates oligodendrocyte lineage differentiation through activation of extracellular signal-regulated kinase signaling pathway. Neuroscience 2007; 151:138-47. [PMID: 18093741 DOI: 10.1016/j.neuroscience.2007.10.050] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2007] [Revised: 08/31/2007] [Accepted: 11/07/2007] [Indexed: 11/15/2022]
Abstract
Platelet-derived growth factor-AA (PDGF-AA) has been used as a potent mitogen for the proliferation of oligodendrocyte progenitor cells (OPCs). Whether it plays a role in oligodendrocyte lineage differentiation of neural stem cells (NSCs) is unclear. Here we report that PDGF-AA is an instructional signal required for the differentiation of embryonic forebrain NSCs into O4-positive oligodendrocytes. Moreover, such PDGF-AA-induced oligodendrocyte differentiation appears to be mediated by the extracellular signal-regulated kinases 1 and 2 (Erk1/2) but not phosphatidylinositol-3 kinase (PI3K) pathway. Finally, PDGF-AA treatment resulted in a significant increase in the expression of the oligodendrocyte-specific transcriptional factor Olig2 in an Erk1/2-dependent mechanism at early stages of oligodendrogliogenesis. Together, our studies provide cellular and molecular evidence to suggest that PDGF-AA is a key molecule that regulates the differentiation of embryonic NSCs into oligodendrocytes. The action of PDGF-AA is mediated by the activation of Erk pathway which involves the downstream upregulation of transcriptional factor Olig2.
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Affiliation(s)
- J-G Hu
- Department of Neurobiology, Shanghai Jiaotong University School of Medicine, Shanghai 200025, People's Republic of China
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28
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Filipczyk AA, Laslett AL, Mummery C, Pera MF. Differentiation is coupled to changes in the cell cycle regulatory apparatus of human embryonic stem cells. Stem Cell Res 2007; 1:45-60. [PMID: 19383386 DOI: 10.1016/j.scr.2007.09.002] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Revised: 08/31/2007] [Accepted: 09/06/2007] [Indexed: 01/06/2023] Open
Abstract
Mouse embryonic stem cells (mESC) exhibit cell cycle properties entirely distinct from those of somatic cells. Here we investigated the cell cycle characteristics of human embryonic stem cells (hESC). HESC could be sorted into populations based on the expression level of the cell surface stem cell marker GCTM-2. Compared to mESC, a significantly higher proportion of hESC (GCTM-2(+) Oct-4(+) cells) resided in G(1) and retained G(1)-phase-specific hypophosphorylated retinoblastoma protein (pRb). We showed that suppression of traverse through G(1) is sufficient to promote hESC differentiation. Like mESC, hESC expressed cyclin E constitutively, were negative for D-type cyclins, and did not respond to CDK-4 inhibition. By contrast, cyclin A expression was periodic in hESC and coincided with S and G(2)/M phase progression. FGF-2 acted solely to sustain hESC pluripotency rather than to promote cell cycle progression or inhibit apoptosis. Differentiation increased G(1)-phase content, reinstated cyclin D activity, and restored the proliferative response to FGF-2. Treatment with CDK-2 inhibitor delayed hESC in G(1) and S phase, resulting in accumulation of cells with hypophosphorylated pRb, GCTM-2, and Oct-4 and, interestingly, a second pRb(+) GCTM-2(+) subpopulation lacking Oct-4. We discuss evidence for a G(1)-specific, pRb-dependent restriction checkpoint in hESC closely associated with the regulation of pluripotency.
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Affiliation(s)
- Adam A Filipczyk
- Netherlands Institute for Developmental Biology and Stem Cell Research, Utrecht, The Netherlands
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29
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Oh SKW, Choo ABH. Human embryonic stem cells: technological challenges towards therapy. Clin Exp Pharmacol Physiol 2007; 33:489-95. [PMID: 16700884 DOI: 10.1111/j.1440-1681.2006.04397.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
1. Human embryonic stem cells (hESC) hold promise for overcoming many diseases because they provide a potential source for many of the slow-growing cell types needed for effective tissue repair, such as the dopaminergic neural cells for Parkinson's disease or the pancreatic islet cells needed to relieve diabetic patients of their daily insulin injections. 2. Human embryonic stem cells can be characterized by several surface antigen markers, transcription factors and enzymes, as well as their ability to differentiate into cells representative of the three germ layers, both in vivo and in vitro. 3. Significant progress has been made in defining the feeder-free and serum-free conditions needed for the culture of hESC. The fibroblast growth factor-2 and transforming growth factor-b signalling pathways appear to be important in maintaining self-renewal and preventing differentiation, respectively. 4. Several important quality controls, including karyotyping, immunogenicity and murine viral assays, will have to be established to monitor the production of hESC for therapeutic purposes. 5. Methods of expansion and differentiation of hESC are still in their infancy and the efficiency of these processes needs to be significantly enhanced.
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Affiliation(s)
- Steve K W Oh
- Stem Cell Group, Bioprocessing Technology Institute, Singapore.
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30
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Derda R, Li L, Orner BP, Lewis RL, Thomson JA, Kiessling LL. Defined substrates for human embryonic stem cell growth identified from surface arrays. ACS Chem Biol 2007; 2:347-55. [PMID: 17480050 DOI: 10.1021/cb700032u] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Methods for the rapid identification of defined cell growth conditions are lacking. This deficiency is a major barrier to the investigation and application of human embryonic stem (ES) cells. To address this problem, we developed a method for generating arrays of self-assembled monolayers (SAMs) in which each element constitutes a defined surface. By screening surface arrays, we identified peptidic surfaces that support ES cell growth and self-renewal. The ability of the active surface array elements to support ES cell growth depends on their composition: both the density of the peptide presented and its sequence are critical. These findings support a role for specific surface-cell interactions. Moreover, the data from the surface arrays are portable. They can be used to design an effective 3D synthetic scaffold that supports the growth of undifferentiated human ES cells. Our results demonstrate that synthetic substrates for promoting and probing human ES cell self-renewal can be discovered through SAM surface arrays.
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Affiliation(s)
- Ratmir Derda
- Department of Chemistry, 1101 University Avenue, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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31
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Establishment and characterization of two new human embryonic stem cell lines, SYSU-1 and SYSU-2. Chin Med J (Engl) 2007. [DOI: 10.1097/00029330-200704010-00012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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32
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Liu N, Lu M, Tian X, Han Z. Molecular mechanisms involved in self-renewal and pluripotency of embryonic stem cells. J Cell Physiol 2007; 211:279-86. [PMID: 17195167 DOI: 10.1002/jcp.20978] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Embryonic stem cells (ES cells) are derived from inner cell mass (ICM). The self-renewal and pluripotency are the main specificities of ES cells, which are likely to reveal a deeper understanding of human cellular biology and which are considered to be promising sources for cell therapy to treat patients with degenerative diseases in clinical. Growth of ES cells as a pluripotent population requires a balance between survival, proliferation, and self-renewal signals. In fact, the precise mechanism that regulates stem cell self-renewal and pluripotency remains largely unknown. Recently, in vitro and in vivo studies have identified several genetic regulators that may play important roles in the self-renewal and pluripotency process of human and mouse ES cells, including extracellular signaling factors, transcription factors, cell-cycle regulators, microRNA, genes implicated in chromosomal stability, and DNA methylation. In this review, we will summarize the currently known molecular regulators for ES cells self-renewal, and we will propose some possibilities to explain the ways in which these distinct pathways might interact.
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Affiliation(s)
- Na Liu
- State Key Laboratory of Experimental Hematology, National Research Center for Stem Cell Engineering and Technology, Institute of Hematology, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
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33
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Avery S, Inniss K, Moore H. The Regulation of Self-Renewal in Human Embryonic Stem Cells. Stem Cells Dev 2006; 15:729-40. [PMID: 17105408 DOI: 10.1089/scd.2006.15.729] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Human embryonic stem (hES) cells have the ability to self-renew while maintaining their pluripotency. The ability of stem cells to self-renew expansively is essential in both development and maintenance of adult tissues. ES cell lines were first generated from mouse blastocysts, these lines provided much needed information regarding ES cell propagation, growth factor dependence, and marker expression. However, the application potential of murine models is restricted in value because many differences between mouse and human ES cells have since been identified. The process of hES cells self-renewal appears to be regulated by many different pathways; however, the molecular mechanisms enabling this process are not fully characterized. Further defining these mechanisms will enable growth of hES cells under defined conditions and aid controlled differentiation of cells into specified lineages, in turn providing cells suitable for therapeutic applications. This review provides a summary of the mechanisms known to control self-renewal and pluripotency in hES cells.
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Affiliation(s)
- Stuart Avery
- Department of Biomedical Sciences, Centre for Stem Cell Biology, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK.
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34
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Oh SKW, Choo ABH. Human embryonic stem cell technology: large scale cell amplification and differentiation. Cytotechnology 2006; 50:181-90. [PMID: 19003078 PMCID: PMC2798940 DOI: 10.1007/s10616-005-3862-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Accepted: 10/07/2005] [Indexed: 12/11/2022] Open
Abstract
Embryonic stem cells (ESC) hold the promise of overcoming many diseases as potential sources of, for example, dopaminergic neural cells for Parkinson’s Disease to pancreatic islets to relieve diabetic patients of their daily insulin injections. While an embryo has the innate capacity to develop fully functional differentiated tissues; biologists are finding that it is much more complex to derive singular, pure populations of primary cells from the highly versatile ESC from this embryonic parent. Thus, a substantial investment in developing the technologies to expand and differentiate these cells is required in the next decade to move this promise into reality. In this review we document the current standard assays for characterising human ESC (hESC), the status of ‘defined’ feeder-free culture conditions for undifferentiated hESC growth, examine the quality controls that will be required to be established for monitoring their growth, review current methods for expansion and differentiation, and speculate on the possible routes of scaling up the differentiation of hESC to therapeutic quantities.
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Affiliation(s)
- Steve K W Oh
- Stem Cell Group, Bioprocessing Technology Institute, 20 Biopolis Way, #06 - 01 Centros, 138668, Singapore, Singapore,
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35
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Watanabe S, Umehara H, Murayama K, Okabe M, Kimura T, Nakano T. Activation of Akt signaling is sufficient to maintain pluripotency in mouse and primate embryonic stem cells. Oncogene 2006; 25:2697-707. [PMID: 16407845 DOI: 10.1038/sj.onc.1209307] [Citation(s) in RCA: 266] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Embryonic stem (ES) cells can self-renew indefinitely without losing their differentiation ability to any cell types. Phosphoinositide-3 kinase (PI3K)/Akt signaling plays a pivotal role in various stem cell systems, including the formation of embryonic germ (EG) cells from primordial germ cells and self-renewal of neural stem cells. Here, we show that myristoylated, active form of Akt (myr-Akt) maintained the undifferentiated phenotypes in mouse ES cells without the addition of leukemia inhibitory factor (LIF). The effects of myr-Akt were reversible, because LIF dependence and pluripotent differentiation activity were restored by the deletion of myr-Akt. In addition, myr-Akt-Mer fusion protein, whose enzymatic activity is controlled by 4-hydroxy-tamoxifen, also maintained the pluripotency of not only mouse but also cynomolgus monkey ES cells. These results clearly demonstrate that Akt signaling sufficiently maintains pluripotency in mouse and primate ES cells, and support the notion that PI3K/Akt signaling axis regulates 'stemness' in a broad spectrum of stem cell systems.
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Affiliation(s)
- S Watanabe
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
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36
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Kueh J, Richards M, Ng SW, Chan WK, Bongso A. The search for factors in human feeders that support the derivation and propagation of human embryonic stem cells: preliminary studies using transcriptome profiling by serial analysis of gene expression. Fertil Steril 2006; 85:1843-6. [PMID: 16674954 DOI: 10.1016/j.fertnstert.2005.11.042] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2005] [Revised: 11/09/2005] [Accepted: 11/09/2005] [Indexed: 11/24/2022]
Abstract
Serial analysis of gene expression (SAGE) was used to obtain the transcriptome profiles of a supportive human fetal skin feeder (Detroit 551) and a nonsupportive human fetal lung feeder (MRC-5) for human embryonic stem cells. A pairwise comparison of the two SAGE profiles showed that fibroblast growth factor-2 (FGF2), a bone morphogenetic protein 4 pathway inhibitor, Gremlin 1, and several extracellular matrix proteins that could potentially aid human embryonic stem cell attachment and growth were highly expressed in Detroit 551 fibroblasts.
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Affiliation(s)
- Jacqueline Kueh
- Department of Obstetrics and Gynecology, National University of Singapore, Kent Ridge, Singapore
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37
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Liu Y, Song Z, Zhao Y, Qin H, Cai J, Zhang H, Yu T, Jiang S, Wang G, Ding M, Deng H. A novel chemical-defined medium with bFGF and N2B27 supplements supports undifferentiated growth in human embryonic stem cells. Biochem Biophys Res Commun 2006; 346:131-9. [PMID: 16753134 DOI: 10.1016/j.bbrc.2006.05.086] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2006] [Accepted: 05/14/2006] [Indexed: 01/08/2023]
Abstract
Traditionally, undifferentiated human embryonic stem cells (hESCs) are maintained on mouse embryonic fibroblast (MEF) cells or on matrigel with an MEF-conditioned medium (CM), which hampers the clinical applications of hESCs due to the contamination by animal pathogens. Here we report a novel chemical-defined medium using DMEM/F12 supplemented with N2, B27, and basic fibroblast growth factor (bFGF) [termed NBF]. This medium can support prolonged self-renewal of hESCs. hESCs cultured in NBF maintain an undifferentiated state and normal karyotype, are able to form embryoid bodies in vitro, and differentiate into three germ layers and extraembryonic cells. Furthermore, we find that hESCs cultured in NBF possess a low apoptosis rate and a high proliferation rate compared with those cultured in MEF-CM. Our findings provide a novel, simplified chemical-defined culture medium suitable for further therapeutic applications and developmental studies of hESCs.
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Affiliation(s)
- Yanxia Liu
- Department of Cell Biology and Genetics, College of Life Sciences, Peking University, Beijing, China
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38
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Kwon YD, Oh SK, Kim HS, Ku SY, Kim SH, Choi YM, Moon SY. Cellular manipulation of human embryonic stem cells by TAT-PDX1 protein transduction. Mol Ther 2006; 12:28-32. [PMID: 15963917 DOI: 10.1016/j.ymthe.2005.03.010] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2005] [Revised: 03/07/2005] [Accepted: 03/16/2005] [Indexed: 12/23/2022] Open
Abstract
Human embryonic stem cells (hESCs) are an in vitro model system for the study of human early development and a potential source for cell-based therapies. An efficient strategy for cellular manipulation of hESCs may be highly valuable for the analysis of gene function involved in human embryogenesis and the development of cell-based therapies via induced differentiation into particular cell types. However, plasmid transfection of hESCs has low efficiency and viral transduction may not be the method of choice for cell-based therapies due to genome integration. To overcome these limitations, we applied protein transduction technology that can transfer proteins into cells via direct penetration across the lipid bilayer. Here, we show that the FITC dye fused to the TAT protein transduction domain (PTD) was efficiently transferred into hESCs. In addition, the PDX1 transcription factor, which plays a central role in pancreatic development, was transferred into hESCs as a fusion form of TAT PTD. The transduced TAT-PDX1 activated its downstream target genes and induced insulin protein production in hESCs. These results demonstrate that protein transduction could be used in the cellular manipulation of hESCs and would provide a significant breakthrough for basic and therapeutic research in hESCs.
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Affiliation(s)
- Young Do Kwon
- Institute of Reproductive Medicine and Population, Medical Research Center, Korea
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39
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Stewart R, Stojkovic M, Lako M. Mechanisms of self-renewal in human embryonic stem cells. Eur J Cancer 2006; 42:1257-72. [PMID: 16630716 DOI: 10.1016/j.ejca.2006.01.033] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2006] [Accepted: 01/23/2006] [Indexed: 01/07/2023]
Abstract
Embryonic stem cells (ESCs) are the pluripotent cell population derived from the inner cell mass of pre-implantation embryos and are characterised by prolonged self-renewal and the potential to differentiate into cells representing all three germ layers both in vitro and in vivo. Preservation of the undifferentiated status of the ESC population requires the maintenance of self-renewal whilst inhibiting differentiation and regulating senescence and apoptosis. In this review, we discuss the intrinsic and extrinsic factors associated with self-renewal process, together with possible signalling pathway interactions and mechanisms of regulation.
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Affiliation(s)
- Rebecca Stewart
- Centre for Stem Cell Biology and Developmental Genetics, Institute of Human Genetics, Newcastle University, International Centre for Life, Central Parkway, Newcastle-Upon-Tyne NE1 3BZ, UK.
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40
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Kalkman HO. The role of the phosphatidylinositide 3-kinase–protein kinase B pathway in schizophrenia. Pharmacol Ther 2006; 110:117-34. [PMID: 16434104 DOI: 10.1016/j.pharmthera.2005.10.014] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2005] [Accepted: 10/26/2005] [Indexed: 01/05/2023]
Abstract
Neuroanatomical studies of brains from schizophrenic patients report evidence for neuronal dystrophy, while in genetic studies in schizophrenia there is evidence for mutations in growth factors and the downstream enzymes phosphatidylinositide 3-kinase (PI3K) and protein kinase B (PKB). Since the PI3K-PKB pathway is involved in cellular growth and proliferation, reduced activity of this cascade in schizophrenia could at least partly explain the neuronal dystrophy. Risk factors for schizophrenia, such as corticosteroids and cannabis, suppress the activity of the PI3K-PKB pathway. Conversely, estrogen and vitamin D, 2 factors with a moderate protective activity in schizophrenia, electroconvulsive shock therapy, and chronic treatment with antipsychotic compounds stimulate the pathway. Reduced activity of the PI3K-PKB pathway makes the brain more susceptible to virus infections, anoxia, and obstetric complications (recognized risk factors for schizophrenia), whereas a diminution of growth factor levels towards the end of puberty could contribute to an increase in schizophrenia symptoms observed around that time. On the other hand, constitutive (over)activation of the PI3K-PKB pathway increases cancer risk. Consequently, the presumed hypoactivity of the PI3K-PKB cascade might provide a partial explanation for the remarkable epidemiological finding of a reduced cancer rate in schizophrenic patients. Recognition of the role of a dysfunctional PI3K-PKB pathway in schizophrenia might help in the discovery of hitherto undetected causative gene mutations and could also lead to novel therapeutic approaches. However, a major challenge that remains to be solved is how the PI3K-PKB pathway can be activated without increasing the risk of cancer.
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Affiliation(s)
- Hans O Kalkman
- Neuroscience Research, Novartis Institutes of Biomedical Research Basel, Building WSJ-360.4.05, Novartis Pharma AG, CH4002 Basel, Switzerland.
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41
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Vallier L, Alexander M, Pedersen RA. Activin/Nodal and FGF pathways cooperate to maintain pluripotency of human embryonic stem cells. J Cell Sci 2006; 118:4495-509. [PMID: 16179608 DOI: 10.1242/jcs.02553] [Citation(s) in RCA: 662] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Maintenance of pluripotency is crucial to the mammalian embryo's ability to generate the extra-embryonic and embryonic tissues that are needed for intrauterine survival and foetal development. The recent establishment of embryonic stem cells from human blastocysts (hESCs) provides an opportunity to identify the factors supporting pluripotency at early stages of human development. Using this in vitro model, we have recently shown that Nodal can block neuronal differentiation, suggesting that TGFbeta family members are involved in cell fate decisions of hESCs, including preservation of their pluripotency. Here, we report that Activin/Nodal signalling through Smad2/3 activation is necessary to maintain the pluripotent status of hESCs. Inhibition of Activin/Nodal signalling by follistatin and by overexpression of Lefty or Cerberus-Short, or by the Activin receptor inhibitor SB431542, precipitates hESC differentiation. Nevertheless, neither Nodal nor Activin is sufficient to sustain long-term hESC growth in a chemically defined medium without serum. Recent studies have shown that FGF2 can also maintain long-term expression of pluripotency markers, and we find that inhibition of the FGF signalling pathway by the tyrosine kinase inhibitor SU5402 causes hESC differentiation. However, this effect of FGF on hESC pluripotency depends on Activin/Nodal signalling, because it is blocked by SB431542. Finally, long-term maintenance of in-vitro pluripotency can be achieved with a combination of Activin or Nodal plus FGF2 in the absence of feeder-cell layers, conditioned medium or Serum Replacer. These findings suggest that the Activin/Nodal pathway maintains pluripotency through mechanism(s) in which FGF acts as a competence factor and therefore provide further evidence of distinct mechanisms for preservation of pluripotency in mouse and human ESCs.
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Affiliation(s)
- Ludovic Vallier
- Department of Surgery and Cambridge Institute for Medical Research, Addenbrooke's Hospital, University of Cambridge, Hills Road, Cambridge CB2 2XY, UK.
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42
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Mallon BS, Park KY, Chen KG, Hamilton RS, McKay RD. Toward xeno-free culture of human embryonic stem cells. Int J Biochem Cell Biol 2006; 38:1063-75. [PMID: 16469522 PMCID: PMC3449300 DOI: 10.1016/j.biocel.2005.12.014] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2005] [Revised: 12/15/2005] [Accepted: 12/17/2005] [Indexed: 10/25/2022]
Abstract
The culture of human embryonic stem cells (hESCs) is limited, both technically and with respect to clinical potential, by the use of mouse embryonic fibroblasts (MEFs) as a feeder layer. The concern over xenogeneic contaminants from the mouse feeder cells may restrict transplantation to humans and the variability in MEFs from batch-to-batch and laboratory-to-laboratory may contribute to some of the variability in experimental results. Finally, use of any feeder layer increases the work load and subsequently limits the large-scale culture of human ES cells. Thus, the development of feeder-free cultures will allow more reproducible culture conditions, facilitate scale-up and potentiate the clinical use of cells differentiated from hESC cultures. In this review, we describe various methods tested to culture cells in the absence of MEF feeder layers and other advances in eliminating xenogeneic products from the culture system.
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43
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Zhang X, Wang S, Yang S, Li T, Ji S, Chen H, Li B, Jin L, Xie Y, Hu Z, Chi J. Feeder layer- and serum-free culture of rhesus monkey embryonic stem cells. Reprod Biomed Online 2006; 13:412-20. [PMID: 16984776 DOI: 10.1016/s1472-6483(10)61447-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The common culture system of rhesus monkey embryonic stem (rES) cells depends largely on feeder cells and serum, which limits the research and application of rES cells. This study reports a feeder layer-free and serum-free system for culture of rES cells. rES cells could be cultured through at least 22 passages on laminin in medium supplemented with serum replacement (SR), basic fibroblast growth factor (bFGF) and transforming growth factor beta1 (TGFbeta1), and maintained stable proliferation rates and normal karyotypes, while displaying all the embryonic stem cell characteristics including morphology, alkaline phosphatase (AKP), Oct-4, cell surface markers SSEA-3, SSEA-4, TRA-1-60 and TRA-1-81, and formed cystic embryoid bodies in vitro. In addition, the studies showed that TGFbeta1, bFGF and laminin are necessary for maintaining the undifferentiated growth of rES cells in long-term culture. Moreover, withdrawal of TGFbeta1 increased the differentiation rate by decreasing the expression of integrins. Therefore, this system would provide a well-defined culture system for rES cells, and would facilitate research into self-renewal and differentiation mechanisms of rES cells.
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Affiliation(s)
- Xiuzhen Zhang
- Department of Reproduction and Development, Kunming Institute of Zoology and Kunming Primate Research Centre, Chinese Academy of Sciences, Kunming, Yunnan, China.
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44
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Li Y, Powell S, Brunette E, Lebkowski J, Mandalam R. Expansion of human embryonic stem cells in defined serum-free medium devoid of animal-derived products. Biotechnol Bioeng 2005; 91:688-98. [PMID: 15971228 DOI: 10.1002/bit.20536] [Citation(s) in RCA: 202] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Human embryonic stem cells (hESCs) can serve as an unlimited cell source for cellular transplantation and tissue engineering due to their prolonged proliferation capacity and their unique ability to differentiate into derivatives of all three-germ layers. In order to reliably and safely produce hESCs, use of reagents that are defined, qualified, and preferably derived from a non-animal source is desirable. Traditionally, mouse embryonic fibroblasts (MEFs) have been used as feeder cells to culture undifferentiated hESCs. We recently reported a scalable feeder-free culture system using medium conditioned by MEFs. The base and conditioned medium (CM) still contain unknown bovine and murine-derived components, respectively. In this study, we report the development of a hESC culture system that utilizes a commercially available serum-free medium (SFM) containing human sourced and recombinant proteins supplemented with recombinant growth factor(s) and does not require conditioning with feeder cells. In this system, which employs human laminin coated surface and high concentration of hbFGF, the hESCs maintained undifferentiated hESC morphology and had a twofold increase in expansion compared to hESCs grown in MEF-CM. The hESCs also expressed surface markers SSEA-4 and Tra-1-60 and maintained expression of hTERT, Oct4, and Cripto genes similar to cells cultured in MEF-CM. In addition, hESCs maintained in this culture system were able to differentiate in vitro and in vivo into cells of all three-germ layers. The cells maintained a normal karyotype after prolonged culture in SFM. In summary, this study demonstrates that the hESCs cultured in defined non-conditioned serum-free medium (NC-SFM) supplemented with growth factor(s) retain the characteristics and replicative potential of hESCs. The use of defined culture system with NC-SFM on human laminin simplifies scale-up and allows for reproducible generation of hESCs under defined and controlled conditions that would serve as a starting material for production of hESC derived cells for therapeutic use.
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Affiliation(s)
- Yan Li
- Geron Corporation, 230 Constitution Drive, Menlo Park, CA 94025, USA
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45
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Levenstein ME, Ludwig TE, Xu RH, Llanas RA, VanDenHeuvel-Kramer K, Manning D, Thomson JA. Basic fibroblast growth factor support of human embryonic stem cell self-renewal. Stem Cells 2005; 24:568-74. [PMID: 16282444 PMCID: PMC4615709 DOI: 10.1634/stemcells.2005-0247] [Citation(s) in RCA: 303] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Human embryonic stem (ES) cells have most commonly been cultured in the presence of basic fibroblast growth factor (FGF2) either on fibroblast feeder layers or in fibroblast-conditioned medium. It has recently been reported that elevated concentrations of FGF2 permit the culture of human ES cells in the absence of fibroblasts or fibroblast-conditioned medium. Herein we compare the ability of unconditioned medium (UM) supplemented with 4, 24, 40, 80, 100, and 250 ng/ml FGF2 to sustain low-density human ES cell cultures through multiple passages. In these stringent culture conditions, 4, 24, and 40 ng/ml FGF2 failed to sustain human ES cells through three passages, but 100 ng/ml sustained human ES cells with an effectiveness comparable to conditioned medium (CM). Two human ES cell lines (H1 and H9) were maintained for up to 164 population doublings (7 and 4 months) in UM supplemented with 100 ng/ml FGF2. After prolonged culture, the cells formed teratomas when injected into severe combined immunodeficient beige mice and expressed markers characteristic of undifferentiated human ES cells. We also demonstrate that FGF2 is degraded more rapidly in UM than in CM, partly explaining the need for higher concentrations of FGF2 in UM. These results further facilitate the large-scale, routine culture of human ES cells and suggest that fibroblasts and fibro-blast-conditioned medium sustain human ES cells in part by stabilizing FGF signaling above a critical threshold.
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Affiliation(s)
| | - Tenneille E. Ludwig
- Wisconsin National Primate Research Center, University of Wisconsin-Madison Medical School and The Genome Center of Wisconsin, Madison, WI 53706
| | - Ren-He Xu
- WiCell Research Institute, Madison, WI 53707-7365
| | | | | | | | - James A. Thomson
- WiCell Research Institute, Madison, WI 53707-7365
- Wisconsin National Primate Research Center, University of Wisconsin-Madison Medical School and The Genome Center of Wisconsin, Madison, WI 53706
- Department of Anatomy, University of Wisconsin-Madison Medical School and The Genome Center of Wisconsin, Madison, WI 53706
- Corresponding author: Dr. James A. Thomson, The Genome Center of Wisconsin, The Genetics and Biotechnology Building, 425 Henry Mall, Madison WI 53706, Phone: 608-263-3585, Fax: 608-890-0167,
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Abstract
Cytokines play a central role in maintaining self-renewal in mouse embryonic stem (ES) cells through a member of the interleukin-6 type cytokine family termed leukemia inhibitory factor (LIF). LIF activates the JAK-STAT3 pathway through the class I cytokine receptor gp130, which forms a trimeric complex with LIF and the class I cytokine receptor LIF receptor beta. STAT3 has been shown to play a crucial role in self-renewal in mouse ES cells probably by induction of c-myc expression. Thus, ablation of STAT3 activation leads to differentiation. However, important connections between STAT3 and other signalling pathways have been documented. In addition, gp130 activation leads to both PI3K and Src activation. The canonical Wnt pathway is sufficient to maintain self-renewal of both human ES cells and mouse ES cells. It seems quite possible that the main pathway maintaining self-renewal in ES cells is the Wnt pathway, while the LIF-JAK-STAT3 pathway is present in mouse cells as an adaptation for sustaining self-renewal during embryonic diapause, a condition of delayed implantation in mammals. In keeping with this scenario, the Wnt pathway has been shown to elevate the level of c-myc. Thus, the two pathways seem to converge on c-myc as a common target to promote self-renewal. Whereas LIF does not seem to stimulate self-renewal in human embryonic stem cells it cannot be excluded that other cytokines are involved. The pleiotropic actions of the increasing number of cytokines and receptors signalling via JAKs, STATs and SOCS exhibit considerable redundancy, compensation and plasticity in stem cells in accordance with the view that stem cells are governed by quantitative variations in strength and duration of signalling events known from other cell types rather than qualitatively different stem cell-specific factors.
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Affiliation(s)
- David Møbjerg Kristensen
- Department of Medical Biochemistry and Genetics, Panum Institute, University of Copenhagen, Copenhagen, Denmark
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47
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Wang Q, Liu Y, Han C. The molecular mechanism of embryonic stem cell pluripotency maintenance. CHINESE SCIENCE BULLETIN-CHINESE 2005. [DOI: 10.1007/bf03182658] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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48
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49
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Nur-E-Kamal A, Ahmed I, Kamal J, Schindler M, Meiners S. Three-dimensional nanofibrillar surfaces promote self-renewal in mouse embryonic stem cells. Stem Cells 2005; 24:426-33. [PMID: 16150921 DOI: 10.1634/stemcells.2005-0170] [Citation(s) in RCA: 193] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The regulation of mouse embryonic stem cell (mESC) fate is controlled by the interplay of signaling networks that either promote self-renewal or induce differentiation. Leukemia inhibitory factor (LIF) is a cytokine that is required for stem cell renewal in mouse but not in human embryonic stem cells. However, feeder layers of embryonic fibroblasts are capable of inducing stem cell renewal in both cell types, suggesting that the self-renewal signaling pathways may also be promoted by other triggers, such as alternative cytokines and/or chemical or physical properties of the extracellular matrix (ECM) secreted by feeder fibroblasts. We have recently used a synthetic polyamide matrix (Ultra-Web) whose three-dimensional (3D) nanofibrillar organization resembles the ECM/basement membrane. Growth of mESCs on this nanofibrillar surface greatly enhanced proliferation and self-renewal in comparison with growth on tissue culture surfaces without nanofibers, despite the presence of LIF in both systems. Enhanced proliferation and self-renewal of the stem cells on nanofibrillar surfaces were correlated with the activation of the small GTPase Rac, the activation of phosphoinositide 3-kinase (PI3K) pathway, and the enhanced expression of Nanog, a homeoprotein required for maintenance of pluripotency. Inhibitors of PI3K reduced the expression level of Nanog in mESCs cultured on 3D nanofibrillar surfaces. These results provide support for the view that the three-dimensionality of the culture surface may function as a cue for the activation of Rac and PI3K signaling pathways, resulting in stem cell proliferation and self-renewal.
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Affiliation(s)
- Alam Nur-E-Kamal
- Department of Pharmacology, UMDNJ-Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, New Jersey 08854, USA.
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50
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Wang G, Zhang H, Zhao Y, Li J, Cai J, Wang P, Meng S, Feng J, Miao C, Ding M, Li D, Deng H. Noggin and bFGF cooperate to maintain the pluripotency of human embryonic stem cells in the absence of feeder layers. Biochem Biophys Res Commun 2005; 330:934-42. [PMID: 15809086 DOI: 10.1016/j.bbrc.2005.03.058] [Citation(s) in RCA: 174] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2005] [Indexed: 01/04/2023]
Abstract
Human embryonic stem (hES) cells are typically maintained on mouse embryonic fibroblast (MEF) feeders or with MEF-conditioned medium. However, these xenosupport systems greatly limit the therapeutic applications of hES cells because of the risk of cross-transfer of animal pathogens. Here we showed that the bone morphogenetic protein antagonist noggin is critical in preventing differentiation of hES cells in culture. Furthermore, we found that the combination of noggin and basic fibroblast growth factor (bFGF) was sufficient to maintain the prolonged growth of hES cells while retaining all hES cell features. Since both noggin and bFGF are expressed in MEF, our findings suggest that they may be important factors secreted by MEF for maintaining undifferentiated pluripotent hES cells. Our data provide new insight into the mechanism how hES cell self-renewal is regulated. The newly developed feeder-free culture system will provide a more reliable alternative for future therapeutic applications of hES cells.
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Affiliation(s)
- Guangwen Wang
- Department of Cell Biology and Genetics, College of Life Sciences, Peking University, Beijing, China
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