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Aparicio G, Arruti C, Zolessi FR. MARCKS phosphorylation by PKC strongly impairs cell polarity in the chick neural plate. Genesis 2018; 56:e23104. [PMID: 29603589 DOI: 10.1002/dvg.23104] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 03/23/2018] [Accepted: 03/25/2018] [Indexed: 12/26/2022]
Abstract
Neurulation involves a complex coordination of cellular movements that are in great part based on the modulation of the actin cytoskeleton. MARCKS, an F-actin-binding protein and the major substrate for PKC, is necessary for gastrulation and neurulation morphogenetic movements in mice, frogs, and fish. We previously showed that this protein accumulates at the apical region of the closing neural plate in chick embryos, and here further explore its role in this process and how it is regulated by PKC phosphorylation. PKC activation by PMA caused extensive neural tube closure defects in cultured chick embryos, together with MARCKS phosphorylation and redistribution to the cytoplasm. This was concomitant with an evident disruption of neural plate cell polarity and extensive apical cell extrusion. This effect was not due to actomyosin hypercontractility, but it was reproduced upon MARCKS knockdown. Interestingly, the overexpression of a nonphosphorylatable form of MARCKS was able to revert the cellular defects observed in the neural plate after PKC activation. Altogether, these results suggest that MARCKS function during neurulation would be to maintain neuroepithelial polarity through the stabilization of subapical F-actin, a function that appears to be counteracted by PKC activation.
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Affiliation(s)
- Gonzalo Aparicio
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay.,Cell Biology of Neural Development Laboratory, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Cristina Arruti
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Flavio R Zolessi
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay.,Cell Biology of Neural Development Laboratory, Institut Pasteur de Montevideo, Montevideo, Uruguay
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2
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Contreras-Vallejos E, Utreras E, Bórquez DA, Prochazkova M, Terse A, Jaffe H, Toledo A, Arruti C, Pant HC, Kulkarni AB, González-Billault C. Searching for novel Cdk5 substrates in brain by comparative phosphoproteomics of wild type and Cdk5-/- mice. PLoS One 2014; 9:e90363. [PMID: 24658276 PMCID: PMC3962345 DOI: 10.1371/journal.pone.0090363] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Accepted: 01/28/2014] [Indexed: 01/07/2023] Open
Abstract
Protein phosphorylation is the most common post-translational modification that regulates several pivotal functions in cells. Cyclin-dependent kinase 5 (Cdk5) is a proline-directed serine/threonine kinase which is mostly active in the nervous system. It regulates several biological processes such as neuronal migration, cytoskeletal dynamics, axonal guidance and synaptic plasticity among others. In search for novel substrates of Cdk5 in the brain we performed quantitative phosphoproteomics analysis, isolating phosphoproteins from whole brain derived from E18.5 Cdk5+/+ and Cdk5−/− embryos, using an Immobilized Metal-Ion Affinity Chromatography (IMAC), which specifically binds to phosphorylated proteins. The isolated phosphoproteins were eluted and isotopically labeled for relative and absolute quantitation (iTRAQ) and mass spectrometry identification. We found 40 proteins that showed decreased phosphorylation at Cdk5−/− brains. In addition, out of these 40 hypophosphorylated proteins we characterized two proteins, :MARCKS (Myristoylated Alanine-Rich protein Kinase C substrate) and Grin1 (G protein regulated inducer of neurite outgrowth 1). MARCKS is known to be phosphorylated by Cdk5 in chick neural cells while Grin1 has not been reported to be phosphorylated by Cdk5. When these proteins were overexpressed in N2A neuroblastoma cell line along with p35, serine phosphorylation in their Cdk5 motifs was found to be increased. In contrast, treatments with roscovitine, the Cdk5 inhibitor, resulted in an opposite effect on serine phosphorylation in N2A cells and primary hippocampal neurons transfected with MARCKS. In summary, the results presented here identify Grin 1 as novel Cdk5 substrate and confirm previously identified MARCKS as a a bona fide Cdk5 substrate.
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Affiliation(s)
- Erick Contreras-Vallejos
- Laboratory of Cellular and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile
| | - Elías Utreras
- Laboratory of Cellular and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile
| | - Daniel A. Bórquez
- Laboratory of Cellular and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile
| | - Michaela Prochazkova
- Functional Genomics Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda MD, USA
| | - Anita Terse
- Functional Genomics Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda MD, USA
| | - Howard Jaffe
- Protein and Peptide Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda MD, USA
| | - Andrea Toledo
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Cristina Arruti
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Harish C. Pant
- Laboratory of Neurochemistry, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda MD, USA
| | - Ashok B. Kulkarni
- Functional Genomics Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda MD, USA
- * E-mail: (CGB); (ABK)
| | - Christian González-Billault
- Laboratory of Cellular and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile
- * E-mail: (CGB); (ABK)
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Tinoco LW, Fraga JL, Anobom CD, Zolessi FR, Obal G, Toledo A, Pritsch O, Arruti C. Structural characterization of a neuroblast-specific phosphorylated region of MARCKS. Biochim Biophys Acta 2014; 1844:837-49. [PMID: 24590112 DOI: 10.1016/j.bbapap.2014.02.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 02/07/2014] [Accepted: 02/20/2014] [Indexed: 11/19/2022]
Abstract
MARCKS (Myristoylated Alanine-Rich C Kinase substrate) is a natively unfolded protein that interacts with actin, Ca(2+)-Calmodulin, and some plasma membrane lipids. Such interactions occur at a highly conserved region that is specifically phosphorylated by PKC: the Effector Domain. There are two other conserved domains, MH1 (including a myristoylation site) and MH2, also located in the amino terminal region and whose structure and putative protein binding capabilities are currently unknown. MH2 sequence contains a serine that we described as being phosphorylated only in differentiating neurons (S25 in chick). Here, Circular Dichroism (CD) and Nuclear Magnetic Resonance (NMR) spectroscopy were used to characterize the phosphorylated and unphosphorylated forms of a peptide with the MARCKS sequence surrounding S25. The peptide phosphorylated at this residue is recognized by monoclonal antibody 3C3 (mAb 3C3). CD and NMR data indicated that S25 phosphorylation does not cause extensive modifications in the peptide structure. However, the sharper lines, the absence of multiple spin systems and relaxation dispersion data observed for the phosphorylated peptide suggested a more ordered structure. Surface Plasmon Resonance was employed to compare the binding properties of mAb 3C3 to MARCKS protein and peptide. SPR showed that mAb 3C3 binds to the whole protein and the peptide with a similar affinity, albeit different kinetics. The slightly ordered structure of the phosphorylated peptide might be at the origin of its ability to interact with mAb 3C3 antibody, but this binding did not noticeably modify the peptide structure.
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Affiliation(s)
- Luzineide W Tinoco
- Instituto de Pesquisas de Produtos Naturais, Universidade Federal do Rio de Janeiro, Cidade Universitária, CCS, Bloco H, Rio de Janeiro 21941-902, RJ, Brazil.
| | - Jully L Fraga
- Instituto de Pesquisas de Produtos Naturais, Universidade Federal do Rio de Janeiro, Cidade Universitária, CCS, Bloco H, Rio de Janeiro 21941-902, RJ, Brazil.
| | - Cristiane D Anobom
- Departamento de Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro, Cidade Universitária, CT, Bloco A, Rio de Janeiro 21941-909, RJ, Brazil.
| | - Flavio R Zolessi
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, DBCM, Facultad de Ciencias, Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay.
| | - Gonzalo Obal
- Unidad de Biofísica de Proteínas, Institut Pasteur de Montevideo, Mataojo 2020, 11400 Montevideo, Uruguay.
| | - Andrea Toledo
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, DBCM, Facultad de Ciencias, Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay.
| | - Otto Pritsch
- Unidad de Biofísica de Proteínas, Institut Pasteur de Montevideo, Mataojo 2020, 11400 Montevideo, Uruguay.
| | - Cristina Arruti
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, DBCM, Facultad de Ciencias, Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay.
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Toledo A, Zolessi FR, Arruti C. A novel effect of MARCKS phosphorylation by activated PKC: the dephosphorylation of its serine 25 in chick neuroblasts. PLoS One 2013; 8:e62863. [PMID: 23634231 PMCID: PMC3636281 DOI: 10.1371/journal.pone.0062863] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 03/25/2013] [Indexed: 12/31/2022] Open
Abstract
MARCKS (Myristoylated Alanine-Rich C Kinase Substrate) is a peripheral membrane protein, especially abundant in the nervous system, and functionally related to actin organization and Ca-calmodulin regulation depending on its phosphorylation by PKC. However, MARCKS is susceptible to be phosphorylated by several different kinases and the possible interactions between these phosphorylations have not been fully studied in intact cells. In differentiating neuroblasts, as well as some neurons, there is at least one cell-type specific phosphorylation site: serine 25 (S25) in the chick. We demonstrate here that S25 is included in a highly conserved protein sequence which is a Cdk phosphorylatable region, located far away from the PKC phosphorylation domain. S25 phosphorylation was inhibited by olomoucine and roscovitine in neuroblasts undergoing various states of cell differentiation in vitro. These results, considered in the known context of Cdks activity in neuroblasts, suggest that Cdk5 is the enzyme responsible for this phosphorylation. We find that the phosphorylation by PKC at the effector domain does not occur in the same molecules that are phosphorylated at serine 25. The in situ analysis of the subcellular distribution of these two phosphorylated MARCKS variants revealed that they are also segregated in different protein clusters. In addition, we find that a sustained stimulation of PKC by phorbol-12-myristate-13-acetate (PMA) provokes the progressive disappearance of phosphorylation at serine 25. Cells treated with PMA, but in the presence of several Ser/Thr phosphatase (PP1, PP2A and PP2B) inhibitors indicated that this dephosphorylation is achieved via a phosphatase 2A (PP2A) form. These results provide new evidence regarding the existence of a novel consequence of PKC stimulation upon the phosphorylated state of MARCKS in neural cells, and propose a link between PKC and PP2A activity on MARCKS.
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Affiliation(s)
- Andrea Toledo
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Flavio R. Zolessi
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Cristina Arruti
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
- * E-mail:
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5
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Aparicio G, Folle M, Arruti C, Zolessi FR. MARCKS subcellular translocation during neural tube closure in the chick, and its modulation by PKC activity. Dev Biol 2011. [DOI: 10.1016/j.ydbio.2011.05.174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Toledo A, Arruti C. Actin modulation of a MARCKS phosphorylation site located outside the effector domain. Biochem Biophys Res Commun 2009; 383:353-7. [DOI: 10.1016/j.bbrc.2009.04.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Accepted: 04/06/2009] [Indexed: 10/20/2022]
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Rivera F, Costa G, Abin A, Urbanavicius J, Arruti C, Casanova G, Dajas F. Reduction of ischemic brain damage and increase of glutathione by a liposomal preparation of quercetin in permanent focal ischemia in rats. Neurotox Res 2008; 13:105-14. [DOI: 10.1007/bf03033562] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Abstract
Myristoylated alanine-rich kinase C substrate (MARCKS), an actin-binding protein, is involved in several signal transduction pathways. It is susceptible to be phosphorylated by protein kinases as protein kinase C and some proline-directed kinases. These phosphorylations differently modulate its functions. We previously showed that a phosphorylation at its Ser25 (S25p-MARCKS) in chickens is a signature of this ubiquitous protein in neuron differentiation. To gain insight into the possible involvement of MARCKS in late retinal histogenesis, we compared the developmental expression patterns of the total protein and its S25p variants. Here we show that the most outstanding modifications occur at the outer retina, where S25p disappears at the end of embryonic development and where MARCKS is missing in adults. These results suggest diverse functional specializations in the different retinal layers.
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Affiliation(s)
- Flavio R Zolessi
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, DBCM, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
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9
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Zolessi FR, Durán R, Engström U, Cerveñansky C, Hellman U, Arruti C. Identification of the chicken MARCKS phosphorylation site specific for differentiating neurons as Ser 25 using a monoclonal antibody and mass spectrometry. J Proteome Res 2004; 3:84-90. [PMID: 14998167 DOI: 10.1021/pr034066f] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
MARCKS is an actin-modulating protein that can be phosphorylated in multiple sites by PKC and proline-directed kinases. We have previously described a phosphorylated form of this protein specific for differentiating chick neurons, detected with mAb 3C3. Here, we show that this antibody binds to MARCKS only when it is phosphorylated at Ser 25. These and previous data provide hints for a possible answer to the question of why this ubiquitous protein seems to be essential only for neural development.
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Affiliation(s)
- Flavio R Zolessi
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, DBCM, Facultad de Ciencias, Universidad de la República, Uruguay
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10
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De María A, Arruti C. DNase I and fragmented chromatin during nuclear degradation in adult bovine lens fibers. Mol Vis 2004; 10:74-82. [PMID: 14961008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023] Open
Abstract
PURPOSE Nuclear loss is a most remarkable organelle disappearance during terminal differentiation of lens fiber cells given that it implicates the full degradation of a major molecular component, DNA. Consequently, to gain insight into the progression of DNA cleavage we analyzed the appearance of single strand breaks in relationship with chromatin condensation. To assess a possible involvement of DNase I in DNA fragmentation we explored its localization in lens fibers having different degrees of nuclear breakdown, evaluated by the state of chromatin, nuclear envelope, and DNA. METHODS Whole mounts of adult bovine lens epithelium as well as lens cryosections were utilized to examine, using antibodies or specific molecular probes, the localization of DNase I, nuclear membrane, lamins, and DNA 3'-OH-free termini. Nuclease activity gel and western blot assays were used to characterize DNase I in different lens fiber extracts. RESULTS Nuclear morphology was found to undergo significant changes from the onset of fiber differentiation. Initial spherical nuclei present at early fibergenesis stages evolve to elongated ones in mature fibers. Chromatin did not present signs of condensation in these nuclei. However, nuclei from fibers located deeper in lens volume exhibited some chromatin condensation and fragmentation while the nuclear lamina appeared undamaged. At more advanced stages, different patterns of nuclear envelope integrity and chromatin condensation and cleavage were observed. DNase I was found in the cytoplasm in the very initial fibers and then in the nuclear territory. DNase I appeared closely associated with fully condensed and fragmented chromatin at the final phases of nuclear breakdown. CONCLUSIONS DNase I is a nuclease present in bovine lens fibers and can be considered as an enzyme producing final DNA cleavage since it is closely associated with highly fragmented DNA in disintegrating nuclei.
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Affiliation(s)
- Alicia De María
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
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De María A, Arruti C. Bovine DNase I: gene organization, mRNA expression, and changes in the topological distribution of the protein during apoptosis in lens epithelial cells. Biochem Biophys Res Commun 2003; 312:634-41. [PMID: 14680812 DOI: 10.1016/j.bbrc.2003.10.161] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2003] [Indexed: 11/16/2022]
Abstract
Genomic DNA sequencing and alignment with the known DNase I mRNA showed that the bovine gene consists of 9 exons and that only the last 8 encode the protein, since initial ATG was found at exon II. RT-PCR was used to identify DNase I mRNA in lens epithelium in vivo and in cultured epithelial cells. We found DNase I transcripts having the same nucleotide sequence as the pancreas form and others lacking almost all exon V. The lens protein presented a slightly higher relative molecular weight than the pancreatic enzyme. Lens DNase I was located in secretory pathway organelles and excluded from the nucleus. Nevertheless, in apoptotic lens epithelial cells in vitro, DNase I translocated to the nucleus and co-localized with TUNEL positive chromatin aggregates. These results indicate that cells in the lens epithelium constitutively express DNase I, and suggest a direct involvement of this nuclease in the final phases of chromatin degradation.
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Affiliation(s)
- Alicia De María
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
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12
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Zolessi FR, Arruti C. Sustained phosphorylation of MARCKS in differentiating neurogenic regions during chick embryo development. Brain Res Dev Brain Res 2001; 130:257-67. [PMID: 11675128 DOI: 10.1016/s0165-3806(01)00251-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
MARCKS, a substrate for several kinases, has critical functions in morphogenetic processes involved in the development of the nervous system. We previously described the purification of MARCKS from chick embryo brain, using a monoclonal antibody (mAb 3C3), raised against embryonic neural retina. Here we show that mAb 3C3 is an antibody sensitive to phosphorylation state. We used it to explore the appearance and developmental progression of phospho-MARCKS (ph-MARCKS) during initial stages of neurogenesis in retina and spinal cord, and compared its distribution with total MARCKS. Before the onset of neural differentiation, MARCKS protein was already accumulated in neural and non-neural embryonic tissues, while ph-MARCKS immunoreactivity was weak, although ubiquitous too. A sudden increase of ph-MARCKS, paralleling a total MARCKS augmentation, was particularly noticeable in the earliest differentiating neurons in the neural retina. Ganglion cells displayed a high ph-MARCKS signal in the soma, as well as in the growing axon. A short time thereafter, a similar increase of ph-MARCKS was present across the entire width of the neural retina, where the differentiation of other neurons and photoreceptors occurs. The increase of ph-MARCKS in cells took place before the detection of the transcription factor Islet-1/2, an early neuronal differentiation molecular marker, in cells of the same region. Analogous phenomena were observed in cervical regions of the spinal cord, where motor neurons were differentiating. Neurogenic regions in the spinal cord contained higher amounts of ph-MARCKS than the floor plate. Taken together, these results strongly suggest that the appearance and relatively long-lasting presence of ph-MARCKS polypeptides are related to specific signaling pathways active during neurogenesis.
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Affiliation(s)
- F R Zolessi
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, Facultad de Ciencias, Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay
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13
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Zolessi FR, Arruti C. Apical accumulation of MARCKS in neural plate cells during neurulation in the chick embryo. BMC Dev Biol 2001; 1:7. [PMID: 11329360 PMCID: PMC31341 DOI: 10.1186/1471-213x-1-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2001] [Accepted: 04/24/2001] [Indexed: 11/15/2022]
Abstract
BACKGROUND The neural tube is formed by morphogenetic movements largely dependent on cytoskeletal dynamics. Actin and many of its associated proteins have been proposed as important mediators of neurulation. For instance, mice deficient in MARCKS, an actin cross-linking membrane-associated protein that is regulated by PKC and other kinases, present severe developmental defects, including failure of cranial neural tube closure. RESULTS To determine the distribution of MARCKS, and its possible relationships with actin during neurulation, chick embryos were transversely sectioned and double labeled with an anti-MARCKS polyclonal antibody and phalloidin. In the neural plate, MARCKS was found ubiquitously distributed at the periphery of the cells, being conspicuously accumulated in the apical cell region, in close proximity to the apical actin meshwork. This asymmetric distribution was particularly noticeable during the bending process. After the closure of the neural tube, the apically accumulated MARCKS disappeared, and this cell region became analogous to the other peripheral cell zones in its MARCKS content. Actin did not display analogous variations, remaining highly concentrated at the cell subapical territory. The transient apical accumulation of MARCKS was found throughout the neural tube axis. The analysis of another epithelial bending movement, during the formation of the lens vesicle, revealed an identical phenomenon. CONCLUSIONS MARCKS is transiently accumulated at the apical region of neural plate and lens placode cells during processes of bending. This asymmetric subcellular distribution of MARCKS starts before the onset of neural plate bending. These results suggest possible upstream regulatory actions of MARCKS on some functions of the actin subapical meshwork.
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Affiliation(s)
- Flavio R Zolessi
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Cristina Arruti
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
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Blasina MF, Faria AC, Gardino PF, Hokoc JN, Almeida OM, de Mello FG, Arruti C, Dajas F. Evidence for a noncholinergic function of acetylcholinesterase during development of chicken retina as shown by fasciculin. Cell Tissue Res 2000; 299:173-84. [PMID: 10741458 DOI: 10.1007/s004419900117] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Fasciculin 2 (FAS), an acetylcholinesterase (AChE) peripheral site ligand that inhibits mammalian AChE in the picomolar range and chicken AChE only at micromolar concentrations, was used in chick retinal cell cultures to evaluate the influence of AChE on neuronal development. The effects of other AChE inhibitors that bind the active and/or the peripheral site of the enzyme [paraoxon, eserine, or 1,5-bis(4-allyldimethylammoniumphenyl) pentan-3-one dibromide (BW284c51)] were also studied. Morphological changes of cultured neurons were observed with the drugs used and in the different cell culture systems studied. Cell aggregates size decreased by more than 35% in diameter after 9 days of FAS treatment, mainly due to reduction in the presumptive plexiform area of the aggregates. Eserine showed no effect on the morphology of the aggregates, although it fully inhibited the activity of AChE. In dense stationary cell culture, cluster formation increased after 3 days and 6 days of FAS treatment. However, FAS, at concentrations in which changes of morphological parameters were observed, did not inhibit the AChE activity as measured histochemically. In contrast, paraoxon treatment produced a slight morphological alteration of the cultures, while a strong inhibition of enzyme activity caused by this agent was observed. BW284c51 showed a harmful, probably toxic effect, also causing a slight AChE inhibition. It is suggested that the effect of an anticholinesterase agent on the morphological modifications of cultured neurons is not necessarily associated with the intensity of the AChE inhibition, especially in the case of FAS. Moreover, most of the effects of AChE on culture morphology appear to be independent of the cholinolytic activity of the enzyme. The results obtained demonstrate that FAS is not toxic for the cells and suggest that regions of the AChE molecule related to the enzyme peripheral site are likely to be involved with the nonclassical role of AChE.
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Affiliation(s)
- M F Blasina
- División Neuroquimica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
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15
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Zolessi FR, Hellman U, Baz A, Arruti C. Characterization of MARCKS (Myristoylated alanine-rich C kinase substrate) identified by a monoclonal antibody generated against chick embryo neural retina. Biochem Biophys Res Commun 1999; 257:480-7. [PMID: 10198238 DOI: 10.1006/bbrc.1999.0490] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To identify molecular markers of cell differentiation in developing nervous tissue, monoclonal antibodies against chick embryo neural retina were made. One of them, 3C3mAb, recognized a developmentally regulated antigen present in several organs of the CNS. Data from MALDI-TOF mass spectrometry and peptide sequencing of the immuno-affinity purified protein indicated identity of the antigen with MARCKS. The immunoreactive material was always found as a unique polypeptide (Mr 71 kDa) in SDS-PAGE, however isoelectrofocusing revealed the existence of several bands (pI ranging from 4.0 to 4.5). Interestingly some retinal cell types, as photoreceptors, exhibited an extremely significant decrease in the intensity of the immunoreactive material during the final phases of terminal differentiation while others, as some retinal neurons, maintained the immunoreactivity when fully differentiated. Taken together these results indicate that MARCKS, a protein susceptible of several posttranslational modifications as myristoylation and phosphorylation at variable extent, may act differently in neural retina cell types.
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Affiliation(s)
- F R Zolessi
- Laboratorio de Cultivo de Tejidos, Sección Biología Celular, Universidad de la República, Montevideo, Uruguay
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Counis MF, Chaudun E, Arruti C, Oliver L, Sanwal M, Courtois Y, Torriglia A. Analysis of nuclear degradation during lens cell differentiation. Cell Death Differ 1998; 5:251-61. [PMID: 10200471 DOI: 10.1038/sj.cdd.4400351] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Lens cells demonstrate a terminal differentiation process with loss of their organelles including nuclei. Chromatin disappearance is characterised by the same changes as most apoptotic cells, i.e. condensation of chromatin and cleavage into high molecular weight fragments and oligonucleosomes. The endo-deoxyribonucleases (bicationic (Ca2+, Mg2+), mono-cationic (Ca2+ or Mg2+) and acidic non-cationic dependent nucleases) are present in lens fibre cells. Our results suggest that the acidic non-cationic nuclease (DNase II) plays a major role in chromatin cleavage. This nuclease, known to be lysosomal, is found in lens fibre nuclei and only an antibody directed against DNase II inhibits the acidic DNA cleavage of lens fibre nuclei. In addition, there must be another DNase implicated in the process which is not DNase I but appears to be a Ca2+, Mg2+ dependent molecule. Regulation of these DNase activities may be accomplished by the effect of post-translational modifications, acidic pH, mitochondrial release molecules, growth factors or oncogenes. Finally, fibre cells lose organelles without cytoplasmic elimination. The survival of these differentiated cells might be due to the action of survival factors such as FGF 1.
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Affiliation(s)
- M F Counis
- U450 INSERM, développement, vieillissement et pathologie de la rétine, Unité associée CNRS, Association Claude Bernard, 29 rue Wilhem, 75016 Paris, France
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17
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de Maria A, Arruti C. alpha-Crystallin polypeptides in developing chicken lens cells. Exp Eye Res 1995; 61:181-7. [PMID: 7556482 DOI: 10.1016/s0014-4835(05)80038-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We provide evidence that the different cells that form the chicken lens have isoelectric variants of alpha-crystallins at early and late developmental stages. We separated the alpha A and alpha B-crystallin subclasses by sodium dodecylsulphate polyacrylamide gel electrophoresis and then further resolved each by isoelectric focusing and assays with specific anti alpha-crystallin antibodies. We found that the annular pad, cortical and nuclear fibers, as well as the epithelial cells, contain alpha A and alpha B native chains and their respective isoelectric variants. These results on adult and embryonic lenses obtained a short time after the onset of alpha-crystallin expression suggest that lens cells, having different phenotypes, are able to produce post-translational modifications of the alpha A and alpha B chains as a part of their developmental program.
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Affiliation(s)
- A de Maria
- Departamento de Biología Celular, Facultad de Ciencias, Universidad de la República, Avda., Montevideo, Uruguay
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18
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Arruti C, Chaudun E, De Maria A, Courtois Y, Counis MF. Characterisation of eye-lens DNases: long term persistence of activity in post apoptotic lens fibre cells. Cell Death Differ 1995; 2:47-56. [PMID: 17180015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/1994] [Accepted: 09/29/1994] [Indexed: 05/13/2023] Open
Abstract
Fibre cells in the ocular lens exhibit a constitutive apoptotic process of nuclear degradation that includes chromatin breakage, generating a ladder pattern of DNA fragments. This process is intrinsic to the normal terminal differentiation program. Despite the loss of nucleus and cytoplasmic organelles, the terminal differentiated fibre cells remain in the lens during the whole life span of the individual. The lens cells thus provide a unique system in which to determine the presence and fate of endonucleases once the chromatin has been cleaved. We report here on the presence of DNase activity in nucleated and anucleated lens cells. Using a nuclease gel assay and double-stranded DNA as substrate, we found active 30 and 60 kDa DNases. The enzymatic activities were Ca(2+), Mg(2+) dependent, and active at neutral pH. The relative amount of these forms changed during development and aging of the lens fibre cells. Both forms were inhibited by Zn(2+), aurintricarboxylic acid, and G-actin. The proteins were also separated by SDS-PAGE, renatured after removing SDS and incubated in the presence of native DNA adsorbed to a membrane. Therefore it was possible to demonstrate, by means of a nick translation reaction, that the enzymes produced single strand cuts. Based on these findings we propose that these chick lens nucleases are probably related to DNase I.
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Affiliation(s)
- C Arruti
- Departamento de Biologia Celular, Facultad de Ciencias y Laboratorio de Cultivo de Tejidos, Facultad de Medicina, Avda, Gral, Flores 2125, Montevideo, Uruguay
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Chaudun E, Arruti C, Courtois Y, Ferrag F, Jeanny JC, Patel BN, Skidmore C, Torriglia A, Counis MF. DNA strand breakage during physiological apoptosis of the embryonic chick lens: free 3' OH end single strand breaks do not accumulate even in the presence of a cation-independent deoxyribonuclease. J Cell Physiol 1994; 158:354-64. [PMID: 8106572 DOI: 10.1002/jcp.1041580218] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Epithelial cells from the lens equator differentiate into elongated fiber cells. In the final steps of differentiation, the chromatin appears quite condensed and chromatin breakdown into nucleosomes occurs. DNA breaks due to an endodeoxyribonuclease activity corresponding to at least two polypeptides of 30 and 40 kDa have been identified. To identify the nature and the developmental appearance of initial breaks, nick translation reaction was followed both biochemically and in situ in fiber and epithelial cells from chick embryonic lenses. There is no accumulation of single-strand breaks (SSB) with 3'OH ends in lens fiber cells during embryonic development. Such damage can be increased in these cells by treatment with DNAase I indicating the absence of an inhibitor of the nick translation reaction in fiber cells. However, there are indications of the presence of DNA breaks with blocked termini when the phosphatase activity of nuclease P1 is used. The presence of breaks is also indicated by the large amounts of (ADP-ribose)n found in lens fibers particularly at 11 days of embryonic development (E11) as ADP-ribosyl transferase binds to and is activated by DNA strand breaks. Incubation of lens cells in vitro, which causes nucleosomal fragmentation only in fiber cells, produces SSB with 3'OH ends in both epithelia and fibers. Incubation for short periods, observed in experiments in situ, induces SSB first in the central fiber nuclei, which are late in differentiation. This may indicate that these SSB play a physiological role. Long incubations produce larger numbers of SSB in epithelia than fibers. The SSB in the fibers may have been converted into double-strand breaks (D SB), seen as nucleosomal fragments, and therefore no longer act as substrates for nick translation. The nuclease activity responsible for SSB production is independent of divalent cations and could be implicated in lens terminal differentiation.
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Affiliation(s)
- E Chaudun
- Unité de Recherches Gérontologiques 118 INSERM, UA 630 CRNS, Paris, France
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Arruti C, Chifflet S. An improved method combining two electrophoretic procedures: application to the separation of lens alpha-crystallin isoforms. Electrophoresis 1991; 12:588-91. [PMID: 1915250 DOI: 10.1002/elps.1150120720] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Polypeptides having different net electric charges and very similar molecular weights, visualized as one single band in sodium dodecyl sulfate--polyacrylamide gel electrophoresis (SDS-PAGE), can be readily analyzed by an improved method combining two electrophoretic procedures. The methodology consists of the identification and isolation of selected protein bands from SDS-PAGE, their equilibration in an isoelectric focusing (IEF) sample buffer, and their casting and separation in an IEF flat-bed gel. This method requires no extra equipment, is highly reproducible, is suitable for quantitative and comparative studies, and is especially useful in the case of small samples. As a particular example, we analyze here the subunit composition of alpha-crystallins of young and embryonic quail lenses.
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Affiliation(s)
- C Arruti
- Departamento de Histología y Embriología, Facultad de Medicina, Montevideo, Uruguay
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21
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Abstract
We have investigated the localization of basic fibroblast growth factor (bFGF) binding sites during the development of the neural retina in the chick embryo. The specificity of the affinity of bFGF for its receptors was assessed by competition experiments with unlabelled growth factor or with heparin, as well as by heparitinase treatment of the samples. Two different types of binding sites were observed in the neural retina by light-microscopic autoradiography. The first type, localized mainly to basement membranes, was highly sensitive to heparitinase digestion and to competition with heparin. It was not developmentally regulated. The second type of binding site, resistant to heparin competition, appeared to be associated with retinal cells from the earliest stages studied (3-day-old embryo, stages 21-22 of Hamburger and Hamilton). Its distribution was found to vary during embryonic development, paralleling layering of the neural retina. Binding of bFGF to the latter sites was observed throughout the retinal neuroepithelium at early stages but displayed a distinct pattern at the time when the inner and outer plexiform layers were formed. During the development of the inner plexiform layer, a banded pattern of bFGF binding was observed. These bands, lying parallel to the vitreal surface, seemed to codistribute with the synaptic bands existing in the inner plexiform layer. The presence of intra-retinal bFGF binding sites whose distribution varies with embryonic development suggests a regulatory mechanism involving differential actions of bFGF on neural retinal cells.
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Affiliation(s)
- A Cirillo
- Laboratorio de Cultivo de Tejidos, Depto de Histología y Embriología, Facultad de Medicina, Montevideo, Uruguay
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Mascarelli F, Courtois Y, Arruti C. The effect of eye-derived-growth-factor (EDGFs) on methionine incorporation in the different cell populations of bovine adult lens in organ culture. Exp Eye Res 1989; 48:177-86. [PMID: 2924806 DOI: 10.1016/s0014-4835(89)80068-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
When adult bovine lenses were cultured in vitro, the purified retina-derived growth factors EDGF I or EDGF II, as well as the soluble fraction of the retina RE, increased the rate of incorporation of [35S]methionine into protein in cells belonging to different populations in the anterior epithelium as well as in fibers from the most superficial region of the cortex. These fiber cells were the most sensitive to stimulation by the retinal factors as they exhibit a significant increase of total protein synthesis 24 hr after addition of the factors to the culture medium. The epithelial cells studied--central epithelial cells and germinative cells--appeared stimulated only 1 day later. The stimulation of incorporation was not directed towards a particular subset of proteins but to all major polypeptides constituting the electrophoretic pattern of each cell population. It is suggested that this type of ocular signal, which stimulates the expression of a definite program, may act as a permissive signal.
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Affiliation(s)
- F Mascarelli
- Unité de Recherches Gérontologiques, U. 118 INSERM, Paris, France
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Abstract
Lenses in organ culture permit an analysis of factors acting on epithelial cell growth, while keeping the normal steric constraints of the cell population. By employing this technique with radioautography of epithelial whole mounts, we showed that the DNA synthesis found in the epithelia of cultured bovine lenses follows an organized spatial and temporal pattern during culture. Within the first 48 h, active cells were located at the preequatorial region ("germinative zone"), a distribution consistent with the in vivo spatial organization of multiplying cells. Starting at about 48 h, cells from the central region of the epithelium--a nonproliferating population--were triggered to synthesize DNA in the presence of eye-derived growth factor (EDGF). When cultured in serum-free medium, only a small fraction of the cells was labeled, but when a low serum concentration was present, this fraction reached 50% of the cell population. The stimulatory effect of EDGF required a lag period, but its effect reached a maximum exceeding that found for serum. However, the cells from the germinative region, having a cell density three- to four-fold higher than the central region, were not stimulated to proliferate. This occurred irrespective of the presence of EDGF or serum. If this growth-stimulatory activity derived from the retina were the actual factor controlling cell proliferation in the lens in vivo, then the results presented here would point to the presence of a regulatory mechanism similar to that known for some other hormones.
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Arruti C, Courtois Y. Monolayer organization by serially cultured bovine corneal endothelial cells: effects of a retina-derived growth-promoting activity. Exp Eye Res 1982; 34:735-47. [PMID: 7084337 DOI: 10.1016/s0014-4835(82)80034-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Courtois Y, Arruti C, Barritault D, Courty J, Tassin J, Olivie M, Plouet J, Laurent M, Perry M. The role of a growth factor derived from the retina (EDGF) in controlling the differentiated stages of several ocular and non-ocular tissues. Adv Exp Med Biol 1982; 158:289-306. [PMID: 7158543 DOI: 10.1007/978-1-4899-5292-9_31] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Courtois Y, Arruti C, Barritault D, Tassin J, Olivié M, Hughes RC. Modulation of the shape of epithelial lens cells in vitro directed by a retinal extract factor. A model of interconversions and the role of actin filaments and fibronectin. Differentiation 1981; 18:11-27. [PMID: 6894433 DOI: 10.1111/j.1432-0436.1981.tb01100.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
We have shown previously [1] that bovine epithelial lens cells can be stimulated to divide and elongate by a retinal extract (RE). In this report we show that the morphological response to the stimulatory factor is directly related to the target-cell shape, and we describe how the cell shape can be modulated into morphologically different types. If the cells are grown continuously from the explant in the presence of the RE factor, they keep a typical regular pavement-like epithelial shape (type I), even after serial passages. If the same cells are cultured in the absence of the factor, they become extremely irregular in shape and enlarge enormously (type II), and during serial passage elongate spontaneously to a fibroblast-like pattern. However, when type II cells are stimulated by RE, they elongate dramatically into type III cells as described in [1], provided they are stimulated at the optimal cell density. We show that the transformation of one type to another is directly under the control of RE, and we demonstrate that the changes in cell morphology are accompanied by alterations in cytoplasmic actin filaments. Type I cells contain few microfilaments, while type II cells display actin-tropomyosin polygonal fibre networks that reform during conversion to type III cells and then to elongated stress fibres. The change from type I to type II cells is also accompanied by massive accumulation of surface-associated fibronectin. We conclude that factors obtained directly from the eye have a direct ability to control morphology and proliferation of ocular cells like lens cells perhaps by modulation of cellular adhesiveness mediated by surface fibronectin and reorganization of cytoplasmic actin-based filaments.
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Barritault D, Arruti C, Courtois Y. Is there a ubiquitous growth factor in the eye? Proliferation induced in different cell types by eye-derived growth factors. Differentiation 1981; 18:29-42. [PMID: 6453034 DOI: 10.1111/j.1432-0436.1981.tb01101.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
In a previous work [1] we showed that a neutral extract of bovine adult retina RE can stimulate the growth and modify the morphology of bovine epithelial lens (BEL) cells in vitro. We were also able to demonstrate that the differences in cell shape are closely related to the cell growth properties induced by RE and are mediated by cytoskeletal protein organization as well as external proteins. In this study, we report the results of further investigations on this retinal extract. We show that it possesses all the characteristics of other growth factors such as promoting proliferation in low serum concentration or of enhancing the colony-forming efficiency of BEL cells considerably. By comparing the morphological response of BEL cells treated with RE with the response of other cells to other growth factors, we propose that the phenotypic modifications are cell specific, but not growth factor specific. We report also that RE has a broad spectrum of activity since it is able to stimulate cells from different origins and species (vascular and corneal endothelial cells, myoblasts, chondrocytes, neuroblastoma cells, and keratinocytes), but not all of them, since it can be toxic for fibroblasts. In this respect, it has an activity similar in many aspects to FGF and EGF, while it differs from them for some target cells. Its action has also been compared with the effects of retinoic acid derivatives and shown to be strikingly different. RE-like activity can be found in other ocular tissues from bovine and other species. The highest growth-promoting capacities were found in extracts of iris, pigmented epithelium with choroid, and vitreous body. The nature of all these extracts has not yet been determined. Since they are prepared in a similar way and since they have similar growth-promoting activity, we postulate that there is an ubiquitous growth factor in the eye called eye-derived growth factor (EDGF) which may play an important role in physiology and pathology of the eye.
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