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Mashanov VS, Zueva OR, García-Arrarás JE. Radial glial cells play a key role in echinoderm neural regeneration. BMC Biol 2013; 11:49. [PMID: 23597108 PMCID: PMC3652774 DOI: 10.1186/1741-7007-11-49] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 04/16/2013] [Indexed: 11/29/2022] Open
Abstract
Background Unlike the mammalian central nervous system (CNS), the CNS of echinoderms is capable of fast and efficient regeneration following injury and constitutes one of the most promising model systems that can provide important insights into evolution of the cellular and molecular events involved in neural repair in deuterostomes. So far, the cellular mechanisms of neural regeneration in echinoderm remained obscure. In this study we show that radial glial cells are the main source of new cells in the regenerating radial nerve cord in these animals. Results We demonstrate that radial glial cells of the sea cucumber Holothuria glaberrima react to injury by dedifferentiation. Both glia and neurons undergo programmed cell death in the lesioned CNS, but it is the dedifferentiated glial subpopulation in the vicinity of the injury that accounts for the vast majority of cell divisions. Glial outgrowth leads to formation of a tubular scaffold at the growing tip, which is later populated by neural elements. Most importantly, radial glial cells themselves give rise to new neurons. At least some of the newly produced neurons survive for more than 4 months and express neuronal markers typical of the mature echinoderm CNS. Conclusions A hypothesis is formulated that CNS regeneration via activation of radial glial cells may represent a common capacity of the Deuterostomia, which is not invoked spontaneously in higher vertebrates, whose adult CNS does not retain radial glial cells. Potential implications for biomedical research aimed at finding the cure for human CNS injuries are discussed.
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Affiliation(s)
- Vladimir S Mashanov
- Department of Biology, University of Puerto Rico, San Juan, PR 00936-8377, USA.
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Abdullayev I, Kirkham M, Björklund ÅK, Simon A, Sandberg R. A reference transcriptome and inferred proteome for the salamander Notophthalmus viridescens. Exp Cell Res 2013; 319:1187-97. [PMID: 23454602 DOI: 10.1016/j.yexcr.2013.02.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 02/15/2013] [Accepted: 02/18/2013] [Indexed: 11/26/2022]
Abstract
Salamanders have a remarkable capacity to regenerate complex tissues, such as limbs and brain, and are therefore an important comparative model system for regenerative medicine. Despite these unique properties among adult vertebrates, the genomic information for amphibians in general, and salamanders in particular, is scarce. Here, we used massive parallel sequencing to reconstruct a de novo reference transcriptome of the red spotted newt (Notophthalmus viridescens) containing 118,893 transcripts with a N50 length of 2016 nts. Comparisons to other vertebrates revealed a newt transcriptome that is comparable in size and characteristics to well-annotated vertebrate transcriptomes. Identification of putative open reading frames (ORFs) enabled us to infer a comprehensive proteome, including the annotation of 19,903 newt proteins. We used the identified domain architectures (DAs) to assign ORFs phylogenetic positions, which also revealed putative salamander specific proteins. The reference transcriptome and inferred proteome of the red spotted newt will facilitate the use of systematic genomic technologies for regeneration studies in salamanders and enable evolutionary analyses of vertebrate regeneration at the molecular level.
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Affiliation(s)
- Ilgar Abdullayev
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
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Cormier Z. Newt sequencing may set back efforts to regrow human limbs. Nature 2013. [DOI: 10.1038/nature.2013.12479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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55
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Looso M, Preussner J, Sousounis K, Bruckskotten M, Michel CS, Lignelli E, Reinhardt R, Höffner S, Krüger M, Tsonis PA, Borchardt T, Braun T. A de novo assembly of the newt transcriptome combined with proteomic validation identifies new protein families expressed during tissue regeneration. Genome Biol 2013; 14:R16. [PMID: 23425577 PMCID: PMC4054090 DOI: 10.1186/gb-2013-14-2-r16] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 02/20/2013] [Indexed: 11/12/2022] Open
Abstract
Background Notophthalmus viridescens, an urodelian amphibian, represents an excellent model organism to study regenerative processes, but mechanistic insights into molecular processes driving regeneration have been hindered by a paucity and poor annotation of coding nucleotide sequences. The enormous genome size and the lack of a closely related reference genome have so far prevented assembly of the urodelian genome. Results We describe the de novo assembly of the transcriptome of the newt Notophthalmus viridescens and its experimental validation. RNA pools covering embryonic and larval development, different stages of heart, appendage and lens regeneration, as well as a collection of different undamaged tissues were used to generate sequencing datasets on Sanger, Illumina and 454 platforms. Through a sequential de novo assembly strategy, hybrid datasets were converged into one comprehensive transcriptome comprising 120,922 non-redundant transcripts with a N50 of 975. From this, 38,384 putative transcripts were annotated and around 15,000 transcripts were experimentally validated as protein coding by mass spectrometry-based proteomics. Bioinformatical analysis of coding transcripts identified 826 proteins specific for urodeles. Several newly identified proteins establish novel protein families based on the presence of new sequence motifs without counterparts in public databases, while others containing known protein domains extend already existing families and also constitute new ones. Conclusions We demonstrate that our multistep assembly approach allows de novo assembly of the newt transcriptome with an annotation grade comparable to well characterized organisms. Our data provide the groundwork for mechanistic experiments to answer the question whether urodeles utilize proprietary sets of genes for tissue regeneration.
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Grigoryan EN, Markitantova YV, Avdonin PP, Radugina EA. Study of regeneration in amphibians in age of molecular-genetic approaches and methods. RUSS J GENET+ 2013. [DOI: 10.1134/s1022795413010043] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Duszynski RJ, Topczewski J, LeClair EE. Divergent requirements for fibroblast growth factor signaling in zebrafish maxillary barbel and caudal fin regeneration. Dev Growth Differ 2013; 55:282-300. [PMID: 23350700 DOI: 10.1111/dgd.12035] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 12/14/2012] [Accepted: 12/14/2012] [Indexed: 12/31/2022]
Abstract
The zebrafish maxillary barbel is an integumentary organ containing skin, glands, pigment cells, taste buds, nerves, and endothelial vessels. The maxillary barbel can regenerate (LeClair & Topczewski 2010); however, little is known about its molecular regulation. We have studied fibroblast growth factor (FGF) pathway molecules during barbel regeneration, comparing this system to a well-known regenerating appendage, the zebrafish caudal fin. Multiple FGF ligands (fgf20a, fgf24), receptors (fgfr1-4) and downstream targets (pea3, il17d) are expressed in normal and regenerating barbel tissue, confirming FGF activation. To test if specific FGF pathways were required for barbel regeneration, we performed simultaneous barbel and caudal fin amputations in two temperature-dependent zebrafish lines. Zebrafish homozygous for a point mutation in fgf20a, a factor essential for caudal fin blastema formation, regrew maxillary barbels normally, indicating that the requirement for this ligand is appendage-specific. Global overexpression of a dominant negative FGF receptor, Tg(hsp70l:dn-fgfr1:EGFP)(pd1) completely blocked fin outgrowth but only partially inhibited barbel outgrowth, suggesting reduced requirements for FGFs in barbel tissue. Maxillary barbels expressing dn-fgfr1 regenerated peripheral nerves, dermal connective tissue, endothelial tubes, and a glandular epithelium; in contrast to a recent report in which dn-fgfr1 overexpression blocks pharyngeal taste bud formation in zebrafish larvae (Kapsimali et al. 2011), we observed robust formation of calretinin-positive tastebuds. These are the first experiments to explore the molecular mechanisms of maxillary barbel regeneration. Our results suggest heterogeneous requirements for FGF signaling in the regeneration of different zebrafish appendages (caudal fin versus maxillary barbel) and taste buds of different embryonic origin (pharyngeal endoderm versus barbel ectoderm).
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Affiliation(s)
- Robert J Duszynski
- Department of Biological Sciences, DePaul University, Chicago, IL 60614, USA
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58
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Garland CB, Pomerantz JH. Regenerative strategies for craniofacial disorders. Front Physiol 2012; 3:453. [PMID: 23248598 PMCID: PMC3521957 DOI: 10.3389/fphys.2012.00453] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Accepted: 11/12/2012] [Indexed: 01/26/2023] Open
Abstract
Craniofacial disorders present markedly complicated problems in reconstruction because of the complex interactions of the multiple, simultaneously affected tissues. Regenerative medicine holds promise for new strategies to improve treatment of these disorders. This review addresses current areas of unmet need in craniofacial reconstruction and emphasizes how craniofacial tissues differ from their analogs elsewhere in the body. We present a problem-based approach to illustrate current treatment strategies for various craniofacial disorders, to highlight areas of need, and to suggest regenerative strategies for craniofacial bone, fat, muscle, nerve, and skin. For some tissues, current approaches offer excellent reconstructive solutions using autologous tissue or prosthetic materials. Thus, new “regenerative” approaches would need to offer major advantages in order to be adopted. In other tissues, the unmet need is great, and we suggest the greatest regenerative need is for muscle, skin, and nerve. The advent of composite facial tissue transplantation and the development of regenerative medicine are each likely to add important new paradigms to our treatment of craniofacial disorders.
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Affiliation(s)
- Catharine B Garland
- Department of Surgery, Division of Plastic and Reconstructive Surgery, University of California San Francisco San Francisco, CA, USA ; Craniofacial and Mesenchymal Biology Program, University of California San Francisco San Francisco, CA, USA
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Sánchez Alvarado A. Q&A: what is regeneration, and why look to planarians for answers? BMC Biol 2012; 10:88. [PMID: 23136835 PMCID: PMC3493261 DOI: 10.1186/1741-7007-10-88] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 11/02/2012] [Indexed: 02/04/2023] Open
Affiliation(s)
- Alejandro Sánchez Alvarado
- Howard Hughes Medical Institute and Stowers Institute for Medical Research, 1000 E. 50th Street, Kansas City, MO 64110, USA.
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60
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Kumar A, Brockes JP. Nerve dependence in tissue, organ, and appendage regeneration. Trends Neurosci 2012; 35:691-9. [PMID: 22989534 DOI: 10.1016/j.tins.2012.08.003] [Citation(s) in RCA: 204] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 08/06/2012] [Accepted: 08/13/2012] [Indexed: 12/20/2022]
Abstract
Many regeneration contexts require the presence of regenerating nerves as a transient component of the progenitor cell niche. Here we review nerve involvement in regeneration of various structures in vertebrates and invertebrates. Nerves are also implicated as persistent determinants in the niche of certain stem cells in mammals, as well as in Drosophila. We consider our present understanding of the cellular and molecular mechanisms underlying nerve dependence, including evidence of critical interactions with glia and non-neural cell types. The example of the salamander aneurogenic limb illustrates that developmental interactions between the limb bud and its innervation can be determinative for adult regeneration. These phenomena provide a different perspective on nerve cells to that based on chemical and electrical excitability.
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Affiliation(s)
- Anoop Kumar
- Institute of Structural and Molecular Biology, Division of Life Sciences, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
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61
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Looso M, Michel CS, Konzer A, Bruckskotten M, Borchardt T, Krüger M, Braun T. Spiked-in Pulsed in Vivo Labeling Identifies a New Member of the CCN Family in Regenerating Newt Hearts. J Proteome Res 2012; 11:4693-704. [DOI: 10.1021/pr300521p] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Mario Looso
- Max-Planck-Institute for Heart and Lung Research, Ludwigstr. 43, 61231 Bad
Nauheim, Germany
| | - Christian S. Michel
- Max-Planck-Institute for Heart and Lung Research, Ludwigstr. 43, 61231 Bad
Nauheim, Germany
| | - Anne Konzer
- Max-Planck-Institute for Heart and Lung Research, Ludwigstr. 43, 61231 Bad
Nauheim, Germany
| | - Marc Bruckskotten
- Max-Planck-Institute for Heart and Lung Research, Ludwigstr. 43, 61231 Bad
Nauheim, Germany
| | - Thilo Borchardt
- Max-Planck-Institute for Heart and Lung Research, Ludwigstr. 43, 61231 Bad
Nauheim, Germany
| | - Marcus Krüger
- Max-Planck-Institute for Heart and Lung Research, Ludwigstr. 43, 61231 Bad
Nauheim, Germany
| | - Thomas Braun
- Max-Planck-Institute for Heart and Lung Research, Ludwigstr. 43, 61231 Bad
Nauheim, Germany
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Ferreira LMR, Floriddia EM, Quadrato G, Di Giovanni S. Neural Regeneration: Lessons from Regenerating and Non-regenerating Systems. Mol Neurobiol 2012; 46:227-41. [DOI: 10.1007/s12035-012-8290-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Accepted: 06/07/2012] [Indexed: 12/22/2022]
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Abstract
Regeneration of complex structures after injury requires dramatic changes in cellular behavior. Regenerating tissues initiate a program that includes diverse processes such as wound healing, cell death, dedifferentiation, and stem (or progenitor) cell proliferation; furthermore, newly regenerated tissues must integrate polarity and positional identity cues with preexisting body structures. Gene knockdown approaches and transgenesis-based lineage and functional analyses have been instrumental in deciphering various aspects of regenerative processes in diverse animal models for studying regeneration.
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Affiliation(s)
- Ryan S King
- Howard Hughes Medical Institute, Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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64
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Simon A, Tanaka EM. Limb regeneration. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2012; 2:291-300. [DOI: 10.1002/wdev.73] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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65
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Agata K, Inoue T. Survey of the differences between regenerative and non-regenerative animals. Dev Growth Differ 2012; 54:143-52. [DOI: 10.1111/j.1440-169x.2011.01323.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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66
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Cernaro V, Lacquaniti A, Donato V, Fazio MR, Buemi A, Buemi M. Fibrosis, regeneration and cancer: what is the link? Nephrol Dial Transplant 2011; 27:21-7. [DOI: 10.1093/ndt/gfr567] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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67
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Seifert AW, Monaghan JR, Smith MD, Pasch B, Stier AC, Michonneau F, Maden M. The influence of fundamental traits on mechanisms controlling appendage regeneration. Biol Rev Camb Philos Soc 2011; 87:330-45. [DOI: 10.1111/j.1469-185x.2011.00199.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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68
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The aneurogenic limb identifies developmental cell interactions underlying vertebrate limb regeneration. Proc Natl Acad Sci U S A 2011; 108:13588-93. [PMID: 21825124 DOI: 10.1073/pnas.1108472108] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The removal of the neural tube in salamander embryos allows the development of nerve-free aneurogenic limbs. Limb regeneration is normally nerve-dependent, but the aneurogenic limb regenerates without nerves and becomes nerve-dependent after innervation. The molecular basis for these tissue interactions is unclear. Anterior Gradient (AG) protein, previously shown to rescue regeneration of denervated limbs and to act as a growth factor for cultured limb blastemal cells, is expressed throughout the larval limb epidermis and is down-regulated by innervation. In an aneurogenic limb, the level of AG protein remains high in the epidermis throughout development and regeneration, but decreases after innervation following transplantation to a normal host. Aneurogenic epidermis also shows a fivefold difference in secretory gland cells, which express AG protein. The persistently high expression of AG in the epithelial cells of an aneurogenic limb ensures that regeneration is independent of the nerve. These findings provide an explanation for this classical problem, and identify regulation of the epidermal niche by innervation as a distinctive developmental mechanism that initiates the nerve dependence of limb regeneration. The absence of this regulation during anuran limb development might suggest that it evolved in relation to limb regeneration.
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69
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Wada N. Spatiotemporal changes in cell adhesiveness during vertebrate limb morphogenesis. Dev Dyn 2011; 240:969-78. [PMID: 21290476 DOI: 10.1002/dvdy.22552] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/22/2010] [Indexed: 12/13/2022] Open
Abstract
During vertebrate limb development, various molecules are expressed in the presumptive limb field or the limb bud in a spatiotemporal-specific manner. The combination of these molecules regulates cellular properties that affect limb initiation and its morphogenesis, especially cartilage formation. Cell adhesiveness of the limb mesenchyme is a key factor in the regulation of cell distribution. Differential adhesiveness of mesenchymal cells is first observed between cells in the presumptive limb field and flank region, and the adhesiveness of the cells in the limb field is higher than that of cells in the flank region. In the limb bud, the adhesiveness of mesenchymal cells shows spatiotemporal difference, which reflects the positional identity of the cells. Position-dependent cell adhesiveness is also observed in blastema cells of the regenerating limb. Therefore, local changes in cell adhesiveness are observed during limb development and regeneration, suggesting significant roles for cell adhesiveness in limb morphogenesis.
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Affiliation(s)
- Naoyuki Wada
- Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Chiba, Japan.
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Fernando WA, Leininger E, Simkin J, Li N, Malcom CA, Sathyamoorthi S, Han M, Muneoka K. Wound healing and blastema formation in regenerating digit tips of adult mice. Dev Biol 2010; 350:301-10. [PMID: 21145316 DOI: 10.1016/j.ydbio.2010.11.035] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Revised: 11/02/2010] [Accepted: 11/27/2010] [Indexed: 11/30/2022]
Abstract
Amputation of the distal region of the terminal phalanx of mice causes an initial wound healing response followed by blastema formation and the regeneration of the digit tip. Thus far, most regeneration studies have focused in embryonic or neonatal models and few studies have examined adult digit regeneration. Here we report on studies that include morphological, immunohistological, and volumetric analyses of adult digit regeneration stages. The regenerated digit is grossly similar to the original, but is not a perfect replacement. Re-differentiation of the digit tip occurs by intramembranous ossification forming a trabecular bone network that replaces the amputated cortical bone. The digit blastema is comprised of proliferating cells that express vimentin, a general mesenchymal marker, and by comparison to mature tissues, contains fewer endothelial cells indicative of reduced vascularity. The majority of blastemal cells expressing the stem cell marker SCA-1, also co-express the endothelial marker CD31, suggesting the presence of endothelial progenitor cells. Epidermal closure during wound healing is very slow and is characterized by a failure of the wound epidermis to close across amputated bone. Instead, the wound healing phase is associated with an osteoclast response that degrades the stump bone allowing the wound epidermis to undercut the distal bone resulting in a novel re-amputation response. Thus, the regeneration process initiates from a level that is proximal to the original plane of amputation.
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Affiliation(s)
- Warnakulasuriya Akash Fernando
- Division of Developmental Biology, Department of Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA
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Blassberg RA, Garza-Garcia A, Janmohamed A, Gates PB, Brockes JP. Functional convergence of signalling by GPI-anchored and anchorless forms of a salamander protein implicated in limb regeneration. J Cell Sci 2010; 124:47-56. [PMID: 21118959 DOI: 10.1242/jcs.076331] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The GPI-anchor is an established determinant of molecular localisation and various functional roles have been attributed to it. The newt GPI-anchored three-finger protein (TFP) Prod1 is an important regulator of cell behaviour during limb regeneration, but it is unclear how it signals to the interior of the cell. Prod1 was expressed by transfection in cultured newt limb cells and activated transcription and expression of matrix metalloproteinase 9 (MMP9) by a pathway involving ligand-independent activation of epidermal growth factor receptor (EGFR) signalling and phosphorylation of extracellular regulated kinase 1 and 2 (ERK1/2). This was dependent on the presence of the GPI-anchor and critical residues in the α-helical region of the protein. Interestingly, Prod1 in the axolotl, a salamander species that also regenerates its limbs, was shown to activate ERK1/2 signalling and MMP9 transcription despite being anchorless, and both newt and axolotl Prod1 co-immunoprecipitated with the newt EGFR after transfection. The substitution of the axolotl helical region activated a secreted, anchorless version of the newt molecule. The activity of the newt molecule cannot therefore depend on a unique property conferred by the anchor. Prod1 is a salamander-specific TFP and its interaction with the phylogenetically conserved EGFR has implications for our view of regeneration as an evolutionary variable.
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Affiliation(s)
- Robert A Blassberg
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK
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72
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Abstract
Lens regeneration among vertebrates is basically restricted to some amphibians. The most notable cases are the ones that occur in premetamorphic frogs and in adult newts. Frogs and newts regenerate their lens in very different ways. In frogs the lens is regenerated by transdifferentiation of the cornea and is limited only to a time before metamorphosis. On the other hand, regeneration in newts is mediated by transdifferentiation of the pigment epithelial cells of the dorsal iris and is possible in adult animals as well. Thus, the study of both systems could provide important information about the process. Molecular tools have been developed in frogs and recently also in newts. Thus, the process has been studied at the molecular and cellular levels. A synthesis describing both systems was long due. In this review we describe the process in both Xenopus and the newt. The known molecular mechanisms are described and compared.
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Affiliation(s)
- Jonathan J Henry
- Department of Cell and Developmental Biology, University of Illinois, Urbana, IL 61801, USA.
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73
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Advances in understanding tissue regenerative capacity and mechanisms in animals. Nat Rev Genet 2010; 11:710-22. [PMID: 20838411 DOI: 10.1038/nrg2879] [Citation(s) in RCA: 290] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Questions about how and why tissue regeneration occurs have captured the attention of countless biologists, biomedical engineers and clinicians. Regenerative capacity differs greatly across organs and organisms, and a range of model systems that use different regenerative strategies and that offer different technical advantages have been studied to understand regeneration. Making use of this range of systems and approaches, recent advances have allowed progress to be made in understanding several key issues that are common to natural regenerative events. These issues include: the determination of regenerative capacity; the importance of stem cells, dedifferentiation and transdifferentiation; how regenerative signals are initiated and targeted; and the mechanisms that control regenerative proliferation and patterning.
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