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Gaur M, Ritner C, Sievers R, Pedersen A, Prasad M, Bernstein HS, Yeghiazarians Y. Timed inhibition of p38MAPK directs accelerated differentiation of human embryonic stem cells into cardiomyocytes. Cytotherapy 2011; 12:807-17. [PMID: 20586669 DOI: 10.3109/14653249.2010.491821] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND AIMS Heart failure therapy with human embryonic stem cell (hESC)-derived cardiomyocytes (hCM) has been limited by the low rate of spontaneous hCM differentiation. As others have shown that p38 mitogen-activated protein kinase (p38MAPK) directs neurogenesis from mouse embryonic stem cells, we investigated whether the p38MAPK inhibitor, SB203580, might influence hCM differentiation. METHODS We treated differentiating hESC with SB203580 at specific time-points, and used flow cytometry, immunocytochemistry, quantitative real-time (RT)-polymerase chain reaction (PCR), teratoma formation and transmission electron microscopy to evaluate cardiomyocyte formation. RESULTS We observed that the addition of inhibitor resulted in 2.1-fold enrichment of spontaneously beating human embryoid bodies (hEB) at 21 days of differentiation, and that 25% of treated cells expressed cardiac-specific α-myosin heavy chain. This effect was dependent on the stage of differentiation at which the inhibitor was introduced. Immunostaining and teratoma formation assays demonstrated that the inhibitor did not affect hESC pluripotency; however, treated hESC gave rise to hCM exhibiting increased expression of sarcomeric proteins, including cardiac troponin T, myosin light chain and α-myosin heavy chain. This was consistent with significantly increased numbers of myofibrillar bundles and the appearance of nascent Z-bodies at earlier time-points in treated hCM. Treated hEB also demonstrated a normal karyotype by array comparative genomic hybridization and viability in vivo following injection into mouse myocardium. CONCLUSIONS These studies demonstrate that p38MAPK inhibition accelerates directed hCM differentiation from hESC, and that this effect is developmental stage-specific. The use of this inhibitor should improve our ability to generate hESC-derived hCM for cell-based therapy.
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Affiliation(s)
- Meenakshi Gaur
- Department of Medicine, University of California, San Francisco, California, USA
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52
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The expression of Akt and ERK1/2 proteins decreased in dexamethasone-induced intrauterine growth restricted rat placental development. J Mol Histol 2011; 42:237-49. [DOI: 10.1007/s10735-011-9328-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Accepted: 04/12/2011] [Indexed: 11/26/2022]
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Potential role of KCNQ/M-channels in regulating neuronal differentiation in mouse hippocampal and embryonic stem cell-derived neuronal cultures. Exp Neurol 2011; 229:471-83. [PMID: 21466805 DOI: 10.1016/j.expneurol.2011.03.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Revised: 03/07/2011] [Accepted: 03/24/2011] [Indexed: 11/24/2022]
Abstract
Voltage-gated K(+) channels are key regulators of neuronal excitability, playing major roles in setting resting membrane potential, repolarizing the cell membrane after action potentials and affecting transmitter release. The M-type channel or M-channel is a unique voltage- and ligand-regulated K(+) channel. It is composed of the molecular counterparts KCNQ2 and KCNQ3 (also named Kv7.2 and Kv7.3) channels and expressed in the soma and dendrites of neurons. The present investigation examined the hypothesis that KCNQ2/3 channels played a regulatory role in neuronal differentiation and maturation. In cultured mouse embryonic stem (ES) cells undergoing neuronal differentiation and primary embryonic (E15-17) hippocampal cultures, KCNQ2 and KCNQ3 channels and underlying M-currents were identified. Blocking of KCNQ channels in these cells for 5 days using the specific channel blocker XE991 (10 μM) or linopirdine (30 μM) significantly decreased synaptophysin and syntaxin expression without affecting cell viability. Chronic KCNQ2/3 channel block reduced the expression of vesicular GABA transporter (v-GAT), but not vesicular glutamate transporter (v-GluT). Enhanced ERK1/2 phosphorylation was observed in XE991- and linopirdine-treated neural progenitor cells. In electrophysiological recordings, cells undergoing chronic block of KCNQ2/3 channels showed normal amplitude of mPSCs while the frequency of mPSCs was reduced. On the other hand, KCNQ channel opener N-Ethylmaleimide (NEM, 2 μM) increased mPSC frequency. Fluorescent imaging using fluorescent styryl-dye FM4-64 revealed that chronic blockade of KCNQ2/3 channels decreased endocytosis but facilitated exocytosis. These data indicate that KCNQ2/3 channels participate in the regulation of neuronal differentiation and show a tonic regulation on pre-synaptic transmitter release and recycling in developing neuronal cells.
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Promoting effects of isobavachin on neurogenesis of mouse embryonic stem cells were associated with protein prenylation. Acta Pharmacol Sin 2011; 32:425-32. [PMID: 21441946 DOI: 10.1038/aps.2011.5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
AIM Some small molecules can induce mouse embryonic stem (ES) cells to differentiate into neuronal cells. Here, we explored the effect of isobavachin (IBA), a compound with a prenyl group at position 8 of ring A, on promoting neuronal differentiation and the potential role of its protein prenylation. METHODS The hanging drop method was employed for embryonic body (EB) formation to mimic embryo development in vivo. The EBs were treated with IBA at a final concentration of 10(-7) mol/L from EB stage (d 4) to d 8+10. Geranylgeranyltransferase I inhibitor GGTI-298 was subsequently used to disrupt protein prenylation. Neuronal subtypes, including neurons and astrocytes, were observed by fluorescence microscopy. Gene and protein expression levels were detected using RT-PCR and Western blot analysis, respectively. RESULTS With IBA treatment, nestin was highly expressed in the neural progenitors generated from EBs (d 4, d 8+0). EBs then further differentiated into neurons (marked by β-tubulin III) and astrocytes (marked by GFAP), which were both up-regulated in a time-dependent manner on d 8+5 and d 8+10. Co-treatment with GGTI-298 selectively abolished the IBA-induced neuronal differentiation. Moreover, in the MAPK pathway, p38 and JNK phosphorylation were down-regulated, while ERK phosphorylation was up-regulated after IBA treatment at different neuronal differentiation passages. CONCLUSION IBA can facilitate mouse ES cells differentiating into neuronal cells. The mechanism involved protein prenylation and, subsequently, phos-ERK activation and the phos-p38 off pathway.
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Chen M, Lin YQ, Xie SL, Wang JF. Mitogen-activated protein kinase in endothelin-1-induced cardiac differentiation of mouse embryonic stem cells. J Cell Biochem 2011; 111:1619-28. [PMID: 21053276 DOI: 10.1002/jcb.22895] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Endothelin-1(ET-1) is a potent vasoconstrictor involved in the development of cardiovascular diseases and is an important regulator of heart development. However, the role of ET-1 in cardiac differentiation of mouse embryonic stem cells (mESCs) and the underlying molecular mechanisms remain poorly understood. In the present study, we showed that ET-1 significantly up-regulated gene expression of the cardiac specific transcriptional factors Nkx2.5, GATA4, and conduction system specific marker CX40, with no affect on the gene expression of α-MHC and β-MHC in cardiac differentiation of mESCs. The percentage of beating embryoid bodies (EB) and the Troponin T (TnT) positive area in total EBs was unchanged following ET-1 treatment, while the percentage of spindle cells that stained positively with TnT was increased in the presence of ET-1. Further investigation indicated that the percentage of beating EBs and the TnT positive area were decreased by the extracellular signal-related kinases (ERK)-1/2 inhibitor U0126 and the p38 inhibitor SB203580, but not by the Jun amino-terminal kinases (JNK) inhibitor SP600125. Inhibition of ERK1/2, p38, and JNK pathways also blocked the up-regulation of Nkx2.5 and GATA4 by ET-1, however only inhibition of the ERK1/2 pathway had negatively effects on the increase in CX40 expression in response to ET-1. ET-1 induced an increase in the percentage of spindle cells was also inhibited by U0126. Our results suggest that ET-1 plays a significant role in the cardiac differentiation of mESCs, especially in those cells committed to the conduction system, with the ERK1/2 pathway playing a critical role in this process.
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Affiliation(s)
- Ming Chen
- Department of Cardiology, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou, China
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56
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Li QR, Xing XB, Chen TT, Li RX, Dai J, Sheng QH, Xin SM, Zhu LL, Jin Y, Pei G, Kang JH, Li YX, Zeng R. Large scale phosphoproteome profiles comprehensive features of mouse embryonic stem cells. Mol Cell Proteomics 2010; 10:M110.001750. [PMID: 21149613 DOI: 10.1074/mcp.m110.001750] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Embryonic stem cells are pluripotent and capable of unlimited self-renewal. Elucidation of the underlying molecular mechanism may contribute to the advancement of cell-based regenerative medicine. In the present work, we performed a large scale analysis of the phosphoproteome in mouse embryonic stem (mES) cells. Using multiplex strategies, we detected 4581 proteins and 3970 high confidence distinct phosphosites in 1642 phosphoproteins. Notably, 22 prominent phosphorylated stem cell marker proteins with 39 novel phosphosites were identified for the first time by mass spectrometry, including phosphorylation sites in NANOG (Ser-65) and RE1 silencing transcription factor (Ser-950 and Thr-953). Quantitative profiles of NANOG peptides obtained during the differentiation of mES cells revealed that the abundance of phosphopeptides and non-phosphopeptides decreased with different trends. To our knowledge, this study presents the largest global characterization of phosphorylation in mES cells. Compared with a study of ultimately differentiated tissue cells, a bioinformatics analysis of the phosphorylation data set revealed a consistent phosphorylation motif in human and mouse ES cells. Moreover, investigations into phosphorylation conservation suggested that phosphoproteins were more conserved in the undifferentiated ES cell state than in the ultimately differentiated tissue cell state. However, the opposite conclusion was drawn from this conservation comparison with phosphosites. Overall, this work provides an overview of phosphorylation in mES cells and is a valuable resource for the future understanding of basic biology in mES cells.
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Affiliation(s)
- Qing-Run Li
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
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Wu J, Kubota J, Hirayama J, Nagai Y, Nishina S, Yokoi T, Asaoka Y, Seo J, Shimizu N, Kajiho H, Watanabe T, Azuma N, Katada T, Nishina H. p38 Mitogen-Activated Protein Kinase Controls a Switch Between Cardiomyocyte and Neuronal Commitment of Murine Embryonic Stem Cells by Activating Myocyte Enhancer Factor 2C-Dependent Bone Morphogenetic Protein 2 Transcription. Stem Cells Dev 2010; 19:1723-34. [DOI: 10.1089/scd.2010.0066] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Jinzhan Wu
- Department of Developmental and Regenerative Biology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo, Japan
| | - Junko Kubota
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo, Japan
| | - Jun Hirayama
- Medical Top Track Program, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yoko Nagai
- Department of Developmental and Regenerative Biology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo, Japan
| | - Sachiko Nishina
- Department of Ophthalmology, National Center for Child Health and Development, Tokyo, Japan
| | - Tadashi Yokoi
- Department of Developmental and Regenerative Biology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
- Department of Ophthalmology, National Center for Child Health and Development, Tokyo, Japan
| | - Yoichi Asaoka
- Department of Developmental and Regenerative Biology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
| | - Jungwon Seo
- Department of Developmental and Regenerative Biology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo, Japan
| | - Nao Shimizu
- Department of Developmental and Regenerative Biology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo, Japan
| | - Hiroaki Kajiho
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo, Japan
| | - Takashi Watanabe
- Department of Laboratory Medicine, Kyorin University School of Medicine, Tokyo, Japan
| | - Noriyuki Azuma
- Department of Ophthalmology, National Center for Child Health and Development, Tokyo, Japan
| | - Toshiaki Katada
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo, Japan
| | - Hiroshi Nishina
- Department of Developmental and Regenerative Biology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
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58
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Gen Y, Yasui K, Zen Y, Zen K, Dohi O, Endo M, Tsuji K, Wakabayashi N, Itoh Y, Naito Y, Taniwaki M, Nakanuma Y, Okanoue T, Yoshikawa T. SOX2 identified as a target gene for the amplification at 3q26 that is frequently detected in esophageal squamous cell carcinoma. ACTA ACUST UNITED AC 2010; 202:82-93. [PMID: 20875870 DOI: 10.1016/j.cancergencyto.2010.01.023] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2009] [Revised: 12/18/2009] [Accepted: 01/17/2010] [Indexed: 12/20/2022]
Abstract
SOX2 is a transcription factor with a high-mobility group DNA-binding domain that functions as a master regulator during embryogenesis and organogenesis. We investigated DNA copy number aberrations in esophageal squamous cell carcinoma (ESCC) cell lines using a high-density oligonucleotide microarray and found frequent amplification at the chromosomal region 3q26. The estimated extent of the minimal overlapping region of amplification was 1.3 Mb. This chromosomal region includes a single gene, SOX2. The SOX2 protein was overexpressed in cell lines in which the gene was amplified. Knockdown experiments showed that SOX2 promotes proliferation of ESCC cells. Genes potentially modulated by SOX2 were determined by expression array analyses combined with small interfering RNA cell-transfection studies. A copy number gain of SOX2 (>2-fold) was observed in 6 of the 40 primary ESCCs (15%). Immunohistochemical study revealed that expression of the SOX2 protein was significantly elevated in 62 of the 89 ESCC tumors (70%), compared with their nontumorous counterparts, and that upregulated expression of SOX2 was associated with poor differentiation of ESCC. Our results suggest that SOX2 is likely to be a target of the 3q26 amplification and may therefore be involved in the development or progression of ESCC.
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Affiliation(s)
- Yasuyuki Gen
- Department of Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto, Japan
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59
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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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60
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Physicochemical control of adult stem cell differentiation: shedding light on potential molecular mechanisms. J Biomed Biotechnol 2010; 2010:743476. [PMID: 20379388 PMCID: PMC2850549 DOI: 10.1155/2010/743476] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Accepted: 01/27/2010] [Indexed: 12/15/2022] Open
Abstract
Realization of the exciting potential for stem-cell-based biomedical and therapeutic applications, including tissue engineering, requires an understanding of the cell-cell and cell-environment interactions. To this end, recent efforts have been focused on the manipulation of adult stem cell differentiation using inductive soluble factors, designing suitable mechanical environments, and applying noninvasive physical forces. Although each of these different approaches has been successfully applied to regulate stem cell differentiation, it would be of great interest and importance to integrate and optimally combine a few or all of the physicochemical differentiation cues to induce synergistic stem cell differentiation. Furthermore, elucidation of molecular mechanisms that mediate the effects of multiple differentiation cues will enable the researcher to better manipulate stem cell behavior and response.
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61
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Doss MX, Wagh V, Schulz H, Kull M, Kolde R, Pfannkuche K, Nolden T, Himmelbauer H, Vilo J, Hescheler J, Sachinidis A. Global transcriptomic analysis of murine embryonic stem cell-derived brachyury(+) (T) cells. Genes Cells 2010; 15:209-28. [PMID: 20184659 DOI: 10.1111/j.1365-2443.2010.01390.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Brachyury(+) mesodermal cell population with purity over 79% was obtained from differentiating brachyury embryonic stem cells (ESC) generated with brachyury promoter driven enhanced green fluorescent protein and puromycin-N-acetyltransferase. A comprehensive transcriptomic analysis of brachyury(+) cells enriched with puromycin application from 6-day-old embryoid bodies (EBs), 6-day-old control EBs and undifferentiated ESCs led to identification of 1573 uniquely up-regulated and 1549 uniquely down-regulated transcripts in brachyury(+) cells. Furthermore, transcripts up-regulated in brachyury(+) cells have overrepresented the Gene Ontology annotations (cell differentiation, blood vessel morphogenesis, striated muscle development, placenta development and cell motility) and Kyoto Encyclopedia of Genes and Genomes pathway annotations (mitogen-activated protein kinase signaling and transforming growth factor beta signaling). Transcripts representing Larp2 and Ankrd34b are notably up-regulated in brachyury(+) cells. Knockdown of Larp2 resulted in a significantly down-regulation BMP-2 expression, and knockdown of Ankrd34b resulted in alteration of NF-H, PPARγ and PECAM1 expression. The elucidation of transcriptomic signatures of ESCs-derived brachyury(+) cells will contribute toward defining the genetic and cellular identities of presumptive mesodermal cells. Furthermore, there is a possible involvement of Larp2 in the regulation of the late mesodermal marker BMP-2. Ankrd34b might be a positive regulator of neurogenesis and a negative regulator of adipogenesis.
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Affiliation(s)
- Michael Xavier Doss
- Center of Physiology and Pathophysiology, Institute of Neurophysiology, and Center of Molecular Medicine, University of Cologne (CMMC), Robert-Koch Str. 39, 50931 Cologne, GermanyMax-Delbrueck-Center for Molecular Medicine - MDC, Robert-Rössle Str. 10, 13092 Berlin, GermanyInstitute of Computer Science, University of Tartu, Liivi 2, 50409 Tartu, Estonia and Quretec Ltd, Ulikooli 6a, Tartu, EstoniaDepartment of Vertebrate Genomics, Max-Planck-Institute for Molecular Genetics, Ihnestr.73, D-14195 Berlin, Germany
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62
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Séverin S, Ghevaert C, Mazharian A. The mitogen-activated protein kinase signaling pathways: role in megakaryocyte differentiation. J Thromb Haemost 2010; 8:17-26. [PMID: 19874462 DOI: 10.1111/j.1538-7836.2009.03658.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Megakaryopoiesis is a process by which bone marrow progenitor cells develop into mature megakaryocytes (MKs), which in turn produce platelets required for normal hemostasis. The mitogen-activated protein kinases (MAPKs) family comprises four main groups of proteins: extracellular signal-related kinases (ERKs) (ERK1/2 or p44/p42), ERK5, p38MAPKs (alpha, beta, gamma, delta) and c-Jun amino-terminal kinases (JNKs) (JNK 1, 2, 3). These intracellular signaling pathways play a pivotal role in many essential cellular processes including proliferation and differentiation. The purpose of this review is to summarize our current knowledge on the role of MAPKs in MKs, specifically regarding differentiation in immortalized cell lines and primary MKs. A critical role of the MEK (MAPK kinase)-ERK1/2 pathway in MK development has been demonstrated although the details remain controversial. There is at present no functional evidence for a role of p38MAPKs whereas the role of JNKs and ERK5 in MK development is not known. Characterization of these molecular event cascades remains crucial for the understanding of the megakaryopoiesis process.
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Affiliation(s)
- S Séverin
- Centre for Cardiovascular Sciences, Institute for Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
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63
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Hong SK, Yoon S, Moelling C, Arthan D, Park JI. Noncatalytic function of ERK1/2 can promote Raf/MEK/ERK-mediated growth arrest signaling. J Biol Chem 2009; 284:33006-18. [PMID: 19805545 PMCID: PMC2785141 DOI: 10.1074/jbc.m109.012591] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Revised: 09/09/2009] [Indexed: 10/20/2022] Open
Abstract
Kinase activity is known as the key biochemical property of MAPKs. Here, we report that ERK1/2 also utilizes its noncatalytic function to mediate certain signal transductions. Sustained activation of the Raf/MEK/ERK pathway induces growth arrest, accompanied by changes in cell cycle regulators (decreased retinoblastoma phosphorylation, E2F1 down-regulation, and/or p21(CIP1) up-regulation) and cell type-specific changes in morphology and expression of c-Myc or RET in the human tumor lines LNCaP, U251, and TT. Ablation of ERK1/2 by RNA interference abrogated all these effects. However, active site-disabled ERK mutants (ERK1-K71R, ERK2-K52R, and ERK2-D147A), which competitively inhibit activation of endogenous ERK1/2, could not block Raf/MEK-induced growth arrest as well as changes in the cell cycle regulators, although they effectively blocked phosphorylation of the ERK1/2 catalytic activity readouts, p90(RSK) and ELK1, as well as the cell type-specific changes. Because this indicated a potential noncatalytic ERK1/2 function, we generated stable lines of the tumor cells in which both ERK1 and ERK2 were significantly knocked down, and we further investigated the possibility using rat-derived kinase-deficient ERK mutants (ERK2-K52R and ERK2-T183A/Y185F) that were not targeted by human small hairpin RNA. Indeed, ERK2-K52R selectively restored Raf-induced growth inhibitory signaling in ERK1/2-depleted cells, as manifested by regained cellular ability to undergo growth arrest and to control the cell cycle regulators without affecting c-Myc and morphology. However, ERK2-T183A/Y185F was less effective, indicating the requirement of TEY site phosphorylation. Our study suggests that functions of ERK1/2 other than its "canonical" kinase activity are also involved in the pathway-mediated growth arrest signaling.
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Affiliation(s)
- Seung-Keun Hong
- From the Department of Biochemistry, The Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Seunghee Yoon
- From the Department of Biochemistry, The Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Cas Moelling
- From the Department of Biochemistry, The Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Dumrongkiet Arthan
- From the Department of Biochemistry, The Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Jong-In Park
- From the Department of Biochemistry, The Medical College of Wisconsin, Milwaukee, Wisconsin 53226
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64
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Hahn JW, Jagwani S, Kim E, Rendell VR, He J, Ezerskiy LA, Wesselschmidt R, Coscia CJ, Belcheva MM. Mu and kappa opioids modulate mouse embryonic stem cell-derived neural progenitor differentiation via MAP kinases. J Neurochem 2009; 112:1431-41. [PMID: 19895666 DOI: 10.1111/j.1471-4159.2009.06479.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
As embryonic stem cell-derived neural progenitors (NPs) have the potential to be used in cell replacement therapy, an understanding of the signaling mechanisms that regulate their terminal differentiation is imperative. In previous studies, we discovered the presence of functional mu opioid receptors (MOR) and kappa opioid receptors (KOR) in mouse embryonic stem cells and NPs. Here, MOR and KOR immunoreactivity was detected in NP-derived oligodendrocytes during three stages of their maturation in vitro. Moreover, we examined the modulation of retinoic acid-induced NP differentiation to astrocytes and neurons by mu, [D-ala(2), mephe(4), gly-ol(5)] enkephalin, or kappa, U69, 593, opioids. Both opioid agonists inhibited NP-derived neurogenesis and astrogenesis via their corresponding receptors as determined by immunocytochemistry. By administering selective inhibitors, we found that opioid inhibition of NP-derived astrogenesis was driven via extracellular-signal regulated kinase (ERK), while the p38 mitogen-activated protein kinase pathway was implicated in opioid attenuation of neurogenesis. In addition, mu and kappa opioids stimulated oligodendrogenesis from NP-derived NG2(+) oligodendrocyte progenitors via both ERK and p38 signaling pathways. Accordingly, both opioids induced ERK phosphorylation in NG2(+) cells. These results indicate that small molecules, such as MOR and KOR agonists may play a modulatory role in NP terminal differentiation.
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Affiliation(s)
- Jason W Hahn
- EA Doisy Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St Louis, Missouri 63104, USA
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65
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Van Hoof D, Muñoz J, Braam SR, Pinkse MWH, Linding R, Heck AJR, Mummery CL, Krijgsveld J. Phosphorylation dynamics during early differentiation of human embryonic stem cells. Cell Stem Cell 2009; 5:214-26. [PMID: 19664995 DOI: 10.1016/j.stem.2009.05.021] [Citation(s) in RCA: 273] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Revised: 03/31/2009] [Accepted: 05/15/2009] [Indexed: 12/25/2022]
Abstract
Pluripotent stem cells self-renew indefinitely and possess characteristic protein-protein networks that remodel during differentiation. How this occurs is poorly understood. Using quantitative mass spectrometry, we analyzed the (phospho)proteome of human embryonic stem cells (hESCs) during differentiation induced by bone morphogenetic protein (BMP) and removal of hESC growth factors. Of 5222 proteins identified, 1399 were phosphorylated on 3067 residues. Approximately 50% of these phosphosites were regulated within 1 hr of differentiation induction, revealing a complex interplay of phosphorylation networks spanning different signaling pathways and kinase activities. Among the phosphorylated proteins was the pluripotency-associated protein SOX2, which was SUMOylated as a result of phosphorylation. Using the data to predict kinase-substrate relationships, we reconstructed the hESC kinome; CDK1/2 emerged as central in controlling self-renewal and lineage specification. The findings provide new insights into how hESCs exit the pluripotent state and present the hESC (phospho)proteome resource as a complement to existing pluripotency network databases.
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Affiliation(s)
- Dennis Van Hoof
- Developmental Biology and Stem Cell Research, Hubrecht Institute, Utrecht, The Netherlands
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66
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Kim YE, Park JA, Nam KH, Kwon HJ, Lee Y. Pyrrolidine dithiocarbamate-induced activation of ERK and increased expression of c-Fos in mouse embryonic stem cells. BMB Rep 2009; 42:148-53. [PMID: 19336001 DOI: 10.5483/bmbrep.2009.42.3.148] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pyrrolidine dithiocarbamate (PDTC) is a stable anti-oxidant or pro-oxidant, depending on the situation, and it is widely used to inhibit the activation of NF-kappaB. We recently reported that PDTC activates the MIP-2 gene in a NF-kappaB-independent and c-Jun-dependent manner in macrophage cells. In this work, we found that PDTC activates signal transduction pathways in mouse ES cells. Among the three different mitogen-activated protein kinase (MAPK) pathways, including the extracellular-signal-regulated kinase (ERK), p38 MAP kinase, and stress-activated protein kinase (SAPK)/Jun N-terminal kinase (JNK) pathways, only the ERK pathway was significantly activated in mouse ES cells after stimulation with PDTC. Additionally, we observed a synergistic activation of ERK and induction of c-Fos after stimulation with PDTC in the presence of mouse embryonic fibroblast (MEF) conditioned medium. In contrast, another NF-kappaB inhibitor, BMS-345541, did not activate the MAP kinase pathways or induce expression of c-Fos. These results suggest that changes in the presence of the NF-kappaB inhibitor PDTC should be carefully considered when it used with mouse ES cells.
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Affiliation(s)
- Young-Eun Kim
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju 361-763, Korea
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67
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Geest CR, Coffer PJ. MAPK signaling pathways in the regulation of hematopoiesis. J Leukoc Biol 2009; 86:237-50. [PMID: 19498045 DOI: 10.1189/jlb.0209097] [Citation(s) in RCA: 201] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The MAPKs are a family of serine/threonine kinases that play an essential role in connecting cell-surface receptors to changes in transcriptional programs. MAPKs are part of a three-component kinase module consisting of a MAPK, an upstream MEK, and a MEKK that couples the signals from cell-surface receptors to trigger downstream pathways. Three major groups of MAPKs have been characterized in mammals, including ERKs, JNKs, and p38MAPKs. Over the last decade, extensive work has established that these proteins play critical roles in the regulation of a wide variety of cellular processes including cell growth, migration, proliferation, differentiation, and survival. It has been demonstrated that ERK, JNK, and p38MAPK activity can be regulated in response to a plethora of hematopoietic cytokines and growth factors that play critical roles in hematopoiesis. In this review, we summarize the current understanding of MAPK function in the regulation of hematopoiesis in general and myelopoiesis in particular. In addition, the consequences of aberrant MAPK activation in the pathogenesis of various myeloid malignancies will be discussed.
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Affiliation(s)
- Christian R Geest
- Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
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68
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Lander AD, Gokoffski KK, Wan FYM, Nie Q, Calof AL. Cell lineages and the logic of proliferative control. PLoS Biol 2009; 7:e15. [PMID: 19166268 PMCID: PMC2628408 DOI: 10.1371/journal.pbio.1000015] [Citation(s) in RCA: 208] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2008] [Accepted: 12/06/2008] [Indexed: 12/03/2022] Open
Abstract
It is widely accepted that the growth and regeneration of tissues and organs is tightly controlled. Although experimental studies are beginning to reveal molecular mechanisms underlying such control, there is still very little known about the control strategies themselves. Here, we consider how secreted negative feedback factors ("chalones") may be used to control the output of multistage cell lineages, as exemplified by the actions of GDF11 and activin in a self-renewing neural tissue, the mammalian olfactory epithelium (OE). We begin by specifying performance objectives-what, precisely, is being controlled, and to what degree-and go on to calculate how well different types of feedback configurations, feedback sensitivities, and tissue architectures achieve control. Ultimately, we show that many features of the OE-the number of feedback loops, the cellular processes targeted by feedback, even the location of progenitor cells within the tissue-fit with expectations for the best possible control. In so doing, we also show that certain distinctions that are commonly drawn among cells and molecules-such as whether a cell is a stem cell or transit-amplifying cell, or whether a molecule is a growth inhibitor or stimulator-may be the consequences of control, and not a reflection of intrinsic differences in cellular or molecular character.
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Affiliation(s)
- Arthur D Lander
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, California, United States of America
- Biomedical Engineering, University of California, Irvine, Irvine, California, United States of America
- Center for Complex Biological Systems, University of California, Irvine, Irvine, California, United States of America
| | - Kimberly K Gokoffski
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, California, United States of America
- Anatomy and Neurobiology, University of California, Irvine, Irvine, California, United States of America
- Mathematics, University of California, Irvine, Irvine, California, United States of America
| | - Frederic Y. M Wan
- Center for Complex Biological Systems, University of California, Irvine, Irvine, California, United States of America
- Mathematics, University of California, Irvine, Irvine, California, United States of America
| | - Qing Nie
- Biomedical Engineering, University of California, Irvine, Irvine, California, United States of America
- Center for Complex Biological Systems, University of California, Irvine, Irvine, California, United States of America
- Mathematics, University of California, Irvine, Irvine, California, United States of America
| | - Anne L Calof
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, California, United States of America
- Center for Complex Biological Systems, University of California, Irvine, Irvine, California, United States of America
- Anatomy and Neurobiology, University of California, Irvine, Irvine, California, United States of America
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69
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The regulation of the gap junction of human mesenchymal stem cells through the internalization of quantum dots. Biomaterials 2009; 30:1937-46. [PMID: 19135246 DOI: 10.1016/j.biomaterials.2008.12.039] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Accepted: 12/16/2008] [Indexed: 01/21/2023]
Abstract
The delivery mechanism of CdSe/ZnS quantum dots (QDs) into cells was previously found to critically determine the biocompatibility of QDs to human adult mesenchymal stem cells, but the associated mechanism remained unknown. The present study tried to establish a link between the above phenomenon and the change in gap junction upon QD internalization. By comparing Pep-1- and PolyFect-mediated QD internalizations, the connexin 43 (Cx43)-mediated gap junction intercellular communication (GJIC) of human adipose-derived adult stem cells was investigated in monolayer and in three-dimensional (3D) culture (alginate hollow spheres). The latter system offered cells more mobility, which was more similar as in vivo. The results showed that Pep-1-coated QDs, which escaped from the endo-/lysosome degradation, could activate the F-actin assembly and the ERK-dependent phosphorylation of Cx43. The consequence was a reduction in Cx43-mediated GJIC. When the cells were grown in high density 3D alginate hollow spheres instead of in monolayer, the decrease of GJIC caused by the QD internalization was restored. These results indicated that the adaptability in QDs-mediated regulation of GJIC with different delivery coatings depended on the culture systems. The study also suggested that the regulation of gap junction may play a key role in QD cytotoxicity.
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70
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Parisuthiman D, Singhatanadgit W, Dechatiwongse T, Koontongkaew S. Cissus quadrangularis extract enhances biomineralization through up-regulation of MAPK-dependent alkaline phosphatase activity in osteoblasts. In Vitro Cell Dev Biol Anim 2008; 45:194-200. [DOI: 10.1007/s11626-008-9158-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2008] [Accepted: 10/20/2008] [Indexed: 01/16/2023]
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Lorthongpanich C, Yang SH, Piotrowska-Nitsche K, Parnpai R, Chan AW. Chemical enhancement in embryo development and stem cell derivation from single blastomeres. CLONING AND STEM CELLS 2008; 10:503-12. [PMID: 18795871 PMCID: PMC3140851 DOI: 10.1089/clo.2008.0035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Several chemicals targeting the mitogen-activated protein (MAP) kinase signaling pathway, which play an important role in regulating cell growth and differentiation, have shown enhancing effects on the development of the inner cell mass (ICM) and the derivation of ES cells. However, investigation of such chemicals on early embryonic development and the establishment of ES cell lines has not been elucidated. This study was aimed to determine if ACTH, MAP2K1 inhibitor [MAP2K1 (I)], and MAPK14 inhibitor [MAPK14 (I)] could enhance the development of the ICM in preimplantation mouse embryos and blastocyst outgrowths, and the establishment of ES cell lines from blastomeres of early embryos. We have demonstrated that both MAP2K1 (I) and MAPK14 (I) delay early embryo development and inhibit the development of embryos from early blastomeres. On the other hand, ACTH had a positive effect on embryos derived from early blastomeres. As a result, 17 ES cell lines were established. Among these ES cell lines, nine and five ES cell lines were established from single blastomeres of two-cell embryos with and without the supplement of ACTH, respectively. In addition to two-cell isolated blastomeres, three ES cell lines were established from blastomeres of four-cell embryos only with the supplement of ACTH. Our results suggest that ACTH can enhance the derivation of ES cells from single blastomere-derived embryos.
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Affiliation(s)
- Chanchao Lorthongpanich
- Yerkes National Primate Research Center, Emory University School of Medicine, Atlanta, Georgia
- Embryo Technology and Stem Cell Research Center, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - Shang-Hsun Yang
- Yerkes National Primate Research Center, Emory University School of Medicine, Atlanta, Georgia
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia
- Genetics and Molecular Biology Program, Emory University School of Medicine, Atlanta, Georgia
| | - Karolina Piotrowska-Nitsche
- Yerkes National Primate Research Center, Emory University School of Medicine, Atlanta, Georgia
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia
- Department of Experimental Embryology, Institute of Genetics and Animal Breeding, Polish Academy of Sciences, 05–552 Wolka Kosowska, Poland
| | - Rangsun Parnpai
- Embryo Technology and Stem Cell Research Center, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - Anthony W.S. Chan
- Yerkes National Primate Research Center, Emory University School of Medicine, Atlanta, Georgia
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia
- Genetics and Molecular Biology Program, Emory University School of Medicine, Atlanta, Georgia
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Wu WKK, Sung JJY, Yu L, Li ZJ, Chu KM, Cho CH. Constitutive hypophosphorylation of extracellular signal-regulated kinases-1/2 and down-regulation of c-Jun in human gastric adenocarcinoma. Biochem Biophys Res Commun 2008; 373:330-4. [PMID: 18570890 DOI: 10.1016/j.bbrc.2008.06.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Accepted: 06/10/2008] [Indexed: 12/16/2022]
Abstract
Hyperphosphorylation of extracellular signal-regulated protein kinases-1/2 (ERK1/2) is known to promote cancer cell proliferation. We therefore investigated the constitutive phosphorylation levels of ERK1/2 and the expression of its downstream targets c-Fos, c-Jun, and cyclooxygenase-2 (COX-2) in biopsied human gastric cancer tissues. Results showed that ERK1/2 phosphorylation and c-Jun expression were significantly lowered in gastric cancer compared with the non-cancer adjacent tissues. The expression of c-Fos, however, was not altered while COX-2 was significantly up-regulated. To conclude, we demonstrate that hypophosphorylation of ERK1/2 may occur in gastric cancer. Such discovery may have implication in the application of pathway-directed therapy for this malignant disease.
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Affiliation(s)
- William Ka Kei Wu
- Department of Pharmacology, Basic Medical Sciences Building, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, China
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74
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Alberti K, Davey RE, Onishi K, George S, Salchert K, Seib FP, Bornhäuser M, Pompe T, Nagy A, Werner C, Zandstra PW. Functional immobilization of signaling proteins enables control of stem cell fate. Nat Methods 2008; 5:645-50. [PMID: 18552855 DOI: 10.1038/nmeth.1222] [Citation(s) in RCA: 172] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2008] [Accepted: 05/16/2008] [Indexed: 12/25/2022]
Abstract
The mode of ligand presentation has a fundamental role in organizing cell fate throughout development. We report a rapid and simple approach for immobilizing signaling ligands to maleic anhydride copolymer thin-film coatings, enabling stable signaling ligand presentation at interfaces at defined concentrations. We demonstrate the utility of this platform technology using leukemia inhibitory factor (LIF) and stem cell factor (SCF). Immobilized LIF supported mouse embryonic stem cell (mESC) pluripotency for at least 2 weeks in the absence of added diffusible LIF. Immobilized LIF activated signal transducer and activator of transcription 3 (STAT3) and mitogen-activated protein kinase (MAPK) signaling in a dose-dependent manner. The introduced method allows for the robust investigation of cell fate responses from interface-immobilized ligands.
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Affiliation(s)
- Kristin Alberti
- Leibniz Institute of Polymer Research Dresden, Max Bergmann Center of Biomaterials, Hohe Str. 6, D-01069 Dresden, Germany
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Immunohistochemical markers for corneal stem cells in the early developing human eye. Exp Eye Res 2008; 87:115-21. [PMID: 18571648 DOI: 10.1016/j.exer.2008.05.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Accepted: 05/08/2008] [Indexed: 11/20/2022]
Abstract
The corneal epithelium is continuously being renewed. Differentiated epithelial cells originate from limbal stem cells (LSCs) located in the periphery of the cornea, the corneoscleral limbus. We have recently identified superoxide dismutase 2 (SOD2) and cytokeratin (CK) 15 as limbal basal cell markers and potential markers for LSCs and early transient amplifying cells in human adults. In this study, we describe the development of the ectodermally derived LSCs and the mesodermally derived niche cells from the time at which the cornea is defined (week 6) until the formation of the early limbal niche (week 14) in human embryos and fetuses. The expression of SOD2 and CK15 was investigated together with other recently identified limbal proteins. Previously suggested LSC and differentiation markers (PAX6, aquaporin-1 and nestin) were also investigated. Both SOD2 and CK15 were present in the corneal epithelium from week 6. However, in week 14 they were predominantly expressed in the limbal epithelium. Both proteins were expressed already from week 7 in a stromal triangular region from which the early mesodermal limbal niche most likely originates. PAX6 was expressed in both ectodermally and mesodermally derived parts of the limbal niche, underscoring the importance of PAX6 in niche formation.
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Differences in the protein expression in limbal versus central human corneal epithelium--a search for stem cell markers. Exp Eye Res 2008; 87:96-105. [PMID: 18571161 DOI: 10.1016/j.exer.2008.05.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2007] [Revised: 02/27/2008] [Accepted: 05/02/2008] [Indexed: 12/15/2022]
Abstract
In the search for potential limbal stem cell protein markers, the purpose of this study was to characterize differences in protein expression between human central and limbal corneal epithelium by a proteomic approach using two-dimensional polyacrylamide gel electrophoresis (2D PAGE) combined with mass spectrometry (LC-MS/MS). The results were subsequently confirmed by Western blotting and immunohistochemistry. We detected more than 1000 protein spots in each gel. Thirty-two spots were significantly over-expressed in the central part and 70 spots were significantly over-expressed in the limbal part. We identified 25 different proteins. Among these 11 proteins representing different cellular locations and functions were selected for further investigations. Most interestingly, superoxide dismutase 2 (SOD2), was expressed in clusters of cells in the basal limbal epithelium. Heat shock protein 70 protein 1 (HSP70.1) and annexin I were highly abundant in limbal epithelium, although they were also present in the central epithelium to a minor extent. Among the proteins primarily expressed in the limbal fraction we further identified cytokeratin (CK) 15, CK19 and alpha enolase, which have been reported previously to be related to the limbal basal epithelium. The basal limbal epithelium consists of clusters of slow cycling limbal stem cells and rapid cycling transient amplifying cells. Ideally, proteins exclusively expressed in the limbal part of the epithelium may serve as markers for the basal limbal cells. SOD2 and CK15 identify clusters of limbal basal cells and therefore they may serve as markers for limbal stem cells in conjunction with the earliest transient amplifying cells.
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Krens SFG, Corredor-Adámez M, He S, Snaar-Jagalska BE, Spaink HP. ERK1 and ERK2 MAPK are key regulators of distinct gene sets in zebrafish embryogenesis. BMC Genomics 2008; 9:196. [PMID: 18442396 PMCID: PMC2390552 DOI: 10.1186/1471-2164-9-196] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Accepted: 04/28/2008] [Indexed: 11/20/2022] Open
Abstract
Background The MAPK signaling proteins are involved in many eukaryotic cellular processes and signaling networks. However, specific functions of most of these proteins in vertebrate development remain elusive because of potential redundancies. For instance, the upstream activation pathways for ERK1 and ERK2 are highly similar, and also many of their known downstream targets are common. In contrast, mice and zebrafish studies indicate distinct roles for both ERKs in cellular proliferation, oncogenic transformation and development. A major bottleneck for further studies is that relatively little is known of in vivo downstream signaling specific for these kinases. Results Microarray based gene expression profiling of ERK1 and ERK2 knockdown zebrafish embryos at various stages of early embryogenesis resulted in specific gene expression signature sets that showed pronounced differences in gene ontology analyses. In order to predict functions of these genes, zebrafish specific in silico signaling pathways involved in early embryogenesis were constructed using the GenMAPP program. The obtained transcriptome signatures were analyzed in the BMP, FGF, Nodal and Wnt pathways. Predicted downstream effects of ERK1 and ERK2 knockdown treatments on key pathways responsible for mesendoderm development were confirmed by whole mount in situ hybridization experiments. Conclusion The gene ontology analyses showed that ERK1 and ERK2 target common and distinct gene sets, confirming the difference in knockdown phenotypes and diverse roles for these kinases during embryogenesis. For ERK1 we identified specific genes involved in dorsal-ventral patterning and subsequent embryonic cell migration. For ERK2 we identified genes involved in cell-migration, mesendoderm differentiation and patterning. The specific function of ERK2 in the initiation, maintenance and patterning of mesoderm and endoderm formation was biologically confirmed.
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Affiliation(s)
- S F Gabby Krens
- Institute of Biology, Leiden University, Wassenaarseweg 64, 2333 AL Leiden, The Netherlands.
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Trouillas M, Saucourt C, Duval D, Gauthereau X, Thibault C, Dembele D, Feraud O, Menager J, Rallu M, Pradier L, Boeuf H. Bcl2, a transcriptional target of p38alpha, is critical for neuronal commitment of mouse embryonic stem cells. Cell Death Differ 2008; 15:1450-9. [PMID: 18437159 DOI: 10.1038/cdd.2008.63] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Mouse embryonic stem (ES) cells remain pluripotent in vitro when grown in the presence of leukemia inhibitory factor (LIF) cytokine. LIF starvation leads to cell commitment, and part of the ES-derived differentiated cells die by apoptosis together with caspase3-cleavage and p38alpha activation. Inhibition of p38 activity by chemical compounds (PD169316 and SB203580), along with LIF withdrawal, leads to different outcomes on cell apoptosis, giving the opportunity to study the influence of apoptosis on cell differentiation. By gene profiling studies on ES-derived differentiated cells treated or not with these inhibitors, we have characterized the common and specific set of genes modulated by each inhibitor. We have also identified key genes that might account for their different survival effects. In addition, we have demonstrated that some genes, similarly regulated by both inhibitors (upregulated as Bcl2, Id2, Cd24a or downregulated as Nodal), are bona fide p38alpha targets involved in neurogenesis and found a correlation with their expression profiles and the onset of neuronal differentiation triggered upon retinoic acid treatment. We also showed, in an embryoid body differentiation protocol, that overexpression of EGFP (enhanced green fluorescent protein)-BCL2 fusion protein and repression of p38alpha are essential to increase formation of TUJ1-positive neuronal cell networks along with an increase in Map2-expressing cells.
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Graichen R, Xu X, Braam SR, Balakrishnan T, Norfiza S, Sieh S, Soo SY, Tham SC, Mummery C, Colman A, Zweigerdt R, Davidson BP. Enhanced cardiomyogenesis of human embryonic stem cells by a small molecular inhibitor of p38 MAPK. Differentiation 2007; 76:357-70. [PMID: 18021257 DOI: 10.1111/j.1432-0436.2007.00236.x] [Citation(s) in RCA: 194] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Human embryonic stem cells (hESC) can differentiate to cardiomyocytes in vitro but with generally poor efficiency. Here, we describe a novel method for the efficient generation of cardiomyocytes from hESC in a scalable suspension culture process. Differentiation in serum-free medium conditioned by the cell line END2 (END2-CM) readily resulted in differentiated cell populations with more than 10% cardiomyocytes without further enrichment. By screening candidate molecules, we have identified SB203580, a specific p38 MAP kinase inhibitor, as a potent promoter of hESC-cardiogenesis. SB203580 at concentrations <10 microM, induced more than 20% of differentiated cells to become cardiomyocytes and increased total cell numbers, so that the overall cardiomyocyte yield was approximately 2.5-fold higher than controls. Gene expression indicated that early mesoderm formation was favored in the presence of SB203580. Accordingly, transient addition of the inhibitor at the onset of differentiation only was sufficient to determine the hESC fate. Patch clamp electrophysiology showed that the distribution of cardiomyocyte phenotypes in the population was unchanged by the compound. Interestingly, cardiomyogenesis was strongly inhibited at SB203580 concentrations > or =15 microM. Thus, modulation of the p38MAP kinase pathway, in combination with factors released by END2 cells, plays an essential role in early lineage determination in hESC and the efficiency of cardiomyogenesis. Our findings contribute to transforming human cardiomyocyte generation from hESC into a robust and scalable process.
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Affiliation(s)
- Ralph Graichen
- ES Cell International Pte Ltd., 11 Biopolis Way Singapore 138667, Singapore
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Abstract
Cancer has been seriously threatening the health and life of humans for a long period. Despite the intensive effort put into revealing the underlying mechanisms of cancer, the detailled machinery of carcinogenesis is still far from fully understood. Numerous studies have illustrated that cell signaling is extensively involved in tumor initiation, promotion and progression. Therefore, targeting the key molecules in the oncogenic signaling pathway might be one of the most promising ways to conquer cancer. Some targeted drugs, such as imatinib mesylate (Gleevec), herceptin, gefitinib (Iressa), sorafenib (Nexavar) and sunitinib (Sutent), which evolve from monotarget drug into multitarget ones, have been developed with encouraging effects.
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Affiliation(s)
- Jin Ding
- The International Cooperation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai 200438, China
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