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Albert FW, Somel M, Carneiro M, Aximu-Petri A, Halbwax M, Thalmann O, Blanco-Aguiar JA, Plyusnina IZ, Trut L, Villafuerte R, Ferrand N, Kaiser S, Jensen P, Pääbo S. A comparison of brain gene expression levels in domesticated and wild animals. PLoS Genet 2012; 8:e1002962. [PMID: 23028369 PMCID: PMC3459979 DOI: 10.1371/journal.pgen.1002962] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 08/06/2012] [Indexed: 11/25/2022] Open
Abstract
Domestication has led to similar changes in morphology and behavior in several animal species, raising the question whether similarities between different domestication events also exist at the molecular level. We used mRNA sequencing to analyze genome-wide gene expression patterns in brain frontal cortex in three pairs of domesticated and wild species (dogs and wolves, pigs and wild boars, and domesticated and wild rabbits). We compared the expression differences with those between domesticated guinea pigs and a distant wild relative (Cavia aperea) as well as between two lines of rats selected for tameness or aggression towards humans. There were few gene expression differences between domesticated and wild dogs, pigs, and rabbits (30-75 genes (less than 1%) of expressed genes were differentially expressed), while guinea pigs and C. aperea differed more strongly. Almost no overlap was found between the genes with differential expression in the different domestication events. In addition, joint analyses of all domesticated and wild samples provided only suggestive evidence for the existence of a small group of genes that changed their expression in a similar fashion in different domesticated species. The most extreme of these shared expression changes include up-regulation in domesticates of SOX6 and PROM1, two modulators of brain development. There was almost no overlap between gene expression in domesticated animals and the tame and aggressive rats. However, two of the genes with the strongest expression differences between the rats (DLL3 and DHDH) were located in a genomic region associated with tameness and aggression, suggesting a role in influencing tameness. In summary, the majority of brain gene expression changes in domesticated animals are specific to the given domestication event, suggesting that the causative variants of behavioral domestication traits may likewise be different.
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Affiliation(s)
- Frank W Albert
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
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Insights into Stem Cell Factor chemotactic guidance of neural crest cells revealed by a real-time directionality-based assay. Eur J Cell Biol 2012; 91:375-90. [DOI: 10.1016/j.ejcb.2011.12.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Revised: 12/19/2011] [Accepted: 12/20/2011] [Indexed: 11/23/2022] Open
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Adameyko I, Lallemend F, Furlan A, Zinin N, Aranda S, Kitambi SS, Blanchart A, Favaro R, Nicolis S, Lübke M, Müller T, Birchmeier C, Suter U, Zaitoun I, Takahashi Y, Ernfors P. Sox2 and Mitf cross-regulatory interactions consolidate progenitor and melanocyte lineages in the cranial neural crest. Development 2012; 139:397-410. [PMID: 22186729 DOI: 10.1242/dev.065581] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The cellular origin and molecular mechanisms regulating pigmentation of head and neck are largely unknown. Melanocyte specification is controlled by the transcriptional activity of Mitf, but no general logic has emerged to explain how Mitf and progenitor transcriptional activities consolidate melanocyte and progenitor cell fates. We show that cranial melanocytes arise from at least two different cellular sources: initially from nerve-associated Schwann cell precursors (SCPs) and later from a cellular source that is independent of nerves. Unlike the midbrain-hindbrain cluster from which melanoblasts arise independently of nerves, a large center of melanocytes in and around cranial nerves IX-X is derived from SCPs, as shown by genetic cell-lineage tracing and analysis of ErbB3-null mutant mice. Conditional gain- and loss-of-function experiments show genetically that cell fates in the neural crest involve both the SRY transcription factor Sox2 and Mitf, which consolidate an SCP progenitor or melanocyte fate by cross-regulatory interactions. A gradual downregulation of Sox2 in progenitors during development permits the differentiation of both neural crest- and SCP-derived progenitors into melanocytes, and an initial small pool of nerve-associated melanoblasts expands in number and disperses under the control of endothelin receptor B (Ednrb) and Wnt5a signaling.
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Affiliation(s)
- Igor Adameyko
- Unit of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institute, 17177 Stockholm, Sweden
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Rae J, Viros A, Hayward R, Bennett DC, Dhomen N, Longley BJ, Reis-Filho JS, Marais R. (V600E)Braf::Tyr-CreERT2::K14-Kitl mice do not develop superficial spreading-like melanoma: keratinocyte Kit ligand is insufficient to "translocate" (V600E)Braf-driven melanoma to the epidermis. J Invest Dermatol 2012; 132:488-91. [PMID: 22113477 DOI: 10.1038/jid.2011.341] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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56
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Durkin K, Coppieters W, Drögemüller C, Ahariz N, Cambisano N, Druet T, Fasquelle C, Haile A, Horin P, Huang L, Kamatani Y, Karim L, Lathrop M, Moser S, Oldenbroek K, Rieder S, Sartelet A, Sölkner J, Stålhammar H, Zelenika D, Zhang Z, Leeb T, Georges M, Charlier C. Serial translocation by means of circular intermediates underlies colour sidedness in cattle. Nature 2012; 482:81-4. [PMID: 22297974 DOI: 10.1038/nature10757] [Citation(s) in RCA: 114] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2011] [Accepted: 12/05/2011] [Indexed: 11/09/2022]
Abstract
Colour sidedness is a dominantly inherited phenotype of cattle characterized by the polarization of pigmented sectors on the flanks, snout and ear tips. It is also referred to as 'lineback' or 'witrik' (which means white back), as colour-sided animals typically display a white band along their spine. Colour sidedness is documented at least since the Middle Ages and is presently segregating in several cattle breeds around the globe, including in Belgian blue and brown Swiss. Here we report that colour sidedness is determined by a first allele on chromosome 29 (Cs(29)), which results from the translocation of a 492-kilobase chromosome 6 segment encompassing KIT to chromosome 29, and a second allele on chromosome 6 (Cs(6)), derived from the first by repatriation of fused 575-kilobase chromosome 6 and 29 sequences to the KIT locus. We provide evidence that both translocation events involved circular intermediates. This is the first example, to our knowledge, of a phenotype determined by homologous yet non-syntenic alleles that result from a novel copy-number-variant-generating mechanism.
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Affiliation(s)
- Keith Durkin
- Unit of Animal Genomics, GIGA-R & Faculty of Veterinary Medicine, University of Liège, 4000-Liège (Sart Tilman), Belgium
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57
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Martí RM, Sorolla A, Yeramian A. New therapeutic targets in melanoma. ACTAS DERMO-SIFILIOGRAFICAS 2012; 103:579-90. [PMID: 22261672 DOI: 10.1016/j.ad.2011.08.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Revised: 06/25/2011] [Accepted: 08/10/2011] [Indexed: 01/07/2023] Open
Abstract
Research into molecular targets for drug development in melanoma is starting to bear fruit. Of the drugs tested to date in patients with metastatic melanoma, those that have yielded the best results are V600E BRAF inhibitors in melanomas carrying the V600E mutation; c-kit tyrosine kinase activity inhibitors in melanomas carrying c-kit mutations; and anti-cytotoxic T lymphocyte antigen 4 (CTLA-4) antibodies, which block the mechanisms involved in immune tolerance. Many problems have yet to be resolved in these areas, however, such as the rapid development of resistance to BRAF and c-kit inhibitors and the lack of biomarkers to predict treatment response in the case of CTLA-4 blockers. We review the results of targeted therapy with these and other drugs in metastatic melanoma and discuss what the future holds for this field.
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Affiliation(s)
- R M Martí
- Servicio de Dermatología, Hospital Universitari Arnau de Vilanova, Universitat de Lleida, IRBLLEIDA, Lleida, Spain.
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58
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Targeting the Cellular Signaling: BRAF Inhibition and Beyond for the Treatment of Metastatic Malignant Melanoma. Dermatol Res Pract 2011; 2012:259170. [PMID: 22216021 PMCID: PMC3246694 DOI: 10.1155/2012/259170] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 09/14/2011] [Indexed: 12/19/2022] Open
Abstract
Although advances in cytotoxic treatments have been obtained in several neoplasias, in metastatic melanoma there was no drug able to significantly change the natural history of the disease in the last 30 years. In the last decade, translational research identified important mechanisms in malignant transformation, invasion, and progression. Signaling pathways can be abnormally activated by oncogenes. The identification of oncogenic mutated kinases implicated in this process provides an opportunity for new target therapies. The melanoma dependence on BRAF-mutated kinase allowed the development of inhibitors that produced major responses in clinical trials. This is the beginning of a novel class of drugs in metastatic melanoma; the identification of the transduction signaling networking and other “druggable” kinases is in active research. In this paper, we discuss the ongoing research on cellular signaling inhibition, resistance mechanisms, and strategies to overcome treatment failure.
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59
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Janebodin K, Horst OV, Ieronimakis N, Balasundaram G, Reesukumal K, Pratumvinit B, Reyes M. Isolation and characterization of neural crest-derived stem cells from dental pulp of neonatal mice. PLoS One 2011; 6:e27526. [PMID: 22087335 PMCID: PMC3210810 DOI: 10.1371/journal.pone.0027526] [Citation(s) in RCA: 109] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Accepted: 10/19/2011] [Indexed: 01/09/2023] Open
Abstract
Dental pulp stem cells (DPSCs) are shown to reside within the tooth and play an important role in dentin regeneration. DPSCs were first isolated and characterized from human teeth and most studies have focused on using this adult stem cell for clinical applications. However, mouse DPSCs have not been well characterized and their origin(s) have not yet been elucidated. Herein we examined if murine DPSCs are neural crest derived and determined their in vitro and in vivo capacity. DPSCs from neonatal murine tooth pulp expressed embryonic stem cell and neural crest related genes, but lacked expression of mesodermal genes. Cells isolated from the Wnt1-Cre/R26R-LacZ model, a reporter of neural crest-derived tissues, indicated that DPSCs were Wnt1-marked and therefore of neural crest origin. Clonal DPSCs showed multi-differentiation in neural crest lineage for odontoblasts, chondrocytes, adipocytes, neurons, and smooth muscles. Following in vivo subcutaneous transplantation with hydroxyapatite/tricalcium phosphate, based on tissue/cell morphology and specific antibody staining, the clones differentiated into odontoblast-like cells and produced dentin-like structure. Conversely, bone marrow stromal cells (BMSCs) gave rise to osteoblast-like cells and generated bone-like structure. Interestingly, the capillary distribution in the DPSC transplants showed close proximity to odontoblasts whereas in the BMSC transplants bone condensations were distant to capillaries resembling dentinogenesis in the former vs. osteogenesis in the latter. Thus we demonstrate the existence of neural crest-derived DPSCs with differentiation capacity into cranial mesenchymal tissues and other neural crest-derived tissues. In turn, DPSCs hold promise as a source for regenerating cranial mesenchyme and other neural crest derived tissues.
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Affiliation(s)
- Kajohnkiart Janebodin
- Department of Oral Health Sciences, School of Dentistry, University of Washington, Seattle, Washington, United States of America
- Department of Anatomy, Faculty of Dentistry, Mahidol University, Bangkok, Thailand
| | - Orapin V. Horst
- Departments of Dental Public Health Sciences and Endodontics, School of Dentistry, University of Washington, Seattle, Washington, United States of America
| | - Nicholas Ieronimakis
- Department of Pathology, Institute for Stem Cell and Regenerative Medicine, School of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Gayathri Balasundaram
- Department of Pathology, Institute for Stem Cell and Regenerative Medicine, School of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Kanit Reesukumal
- Department of Clinical Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Busadee Pratumvinit
- Department of Clinical Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Morayma Reyes
- Department of Oral Health Sciences, School of Dentistry, University of Washington, Seattle, Washington, United States of America
- Department of Pathology, Institute for Stem Cell and Regenerative Medicine, School of Medicine, University of Washington, Seattle, Washington, United States of America
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Linskey KR, Dias-Santagata D, Nazarian RM, Le LP, Lam Q, Bellucci KS, Robinson-Bostom L, Mihm MC, Hoang MP. Malignant Neurocristic Hamartoma. Am J Surg Pathol 2011; 35:1570-7. [DOI: 10.1097/pas.0b013e31822389b7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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61
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Serre C, Lebleu A, Bergeron L, Plantivaux A, Botto JM, Dal Farra C, Domloge N. Microarray profiling of gene expression in human keratinocytes suggests a new protective activity against UV-induced DNA damage for a compound previously known to interact with SCF-KIT signalling pathway. Int J Cosmet Sci 2011; 33:398-407. [PMID: 21382056 DOI: 10.1111/j.1468-2494.2011.00641.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The stem cell factor (SCF) and its protein-tyrosine kinase receptor KIT are together implicated in the regulation of diverse biological processes and particularly in melanogenesis. Indeed, this signalling pathway controls melanoblast migration from the neural crest during embryogenesis and allows the communication between keratinocytes and melanocytes in the adult. In melanocytes, the binding of SCF to its transmembrane receptor leads to the activation of signalling pathways implicating protein kinases which finally control the expression of pigmentation-related genes. We have developed a biological compound called IV09.007, which we previously described as a modulator of the SCF/KIT signalling pathway with a pro-pigmenting effect. In the present work, we have studied the expression and localization of both SCF and KIT mRNAs and proteins in the skin or skin-derived cell lines. Then, we explored with a microarray approach the ability of IV09.007 to modulate the expression of genes in human keratinocytes and melanocytes in culture. Thereby, we observed the regulation of genes implicated in DNA repair, mainly related to base/nucleotides excision pathways. A modulated transcriptional response was also observed for some genes implicated in the response against oxidative stress, in apoptosis inhibition and in lowering inflammatory immune response. These microarray results predicted a conferred protective effect of IV09.007 and we verified this hypothesis by performing comet assays on UVB-irradiated keratinocytes or melanocytes, to demonstrate the efficacy of IV09.007 on preventing DNA damage.
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Affiliation(s)
- C Serre
- ISP VINCIENCE, Sophia Antipolis, France
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Stokman G, Stroo I, Claessen N, Teske GJD, Weening JJ, Leemans JC, Florquin S. Stem cell factor expression after renal ischemia promotes tubular epithelial survival. PLoS One 2010; 5:e14386. [PMID: 21200435 PMCID: PMC3006174 DOI: 10.1371/journal.pone.0014386] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Accepted: 11/30/2010] [Indexed: 11/18/2022] Open
Abstract
Background Renal ischemia leads to apoptosis of tubular epithelial cells and results in decreased renal function. Tissue repair involves re-epithelialization of the tubular basement membrane. Survival of the tubular epithelium following ischemia is therefore important in the successful regeneration of renal tissue. The cytokine stem cell factor (SCF) has been shown to protect the tubular epithelium against apoptosis. Methodology/Principal Findings In a mouse model for renal ischemia/reperfusion injury, we studied how expression of c-KIT on tubular epithelium and its ligand SCF protect cells against apoptosis. Administration of SCF specific antisense oligonucleotides significantly decreased specific staining of SCF following ischemia. Reduced SCF expression resulted in impaired renal function, increased tubular damage and increased tubular epithelial apoptosis, independent of inflammation. In an in vitro hypoxia model, stimulation of tubular epithelial cells with SCF activated survival signaling and decreased apoptosis. Conclusions/Significance Our data indicate an important role for c-KIT and SCF in mediating tubular epithelial cell survival via an autocrine pathway.
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Affiliation(s)
- Geurt Stokman
- Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
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63
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Expression and network analysis of genes related to melanocyte development in the Silky Fowl and White Leghorn embryos. Mol Biol Rep 2010; 38:1433-41. [PMID: 20848220 DOI: 10.1007/s11033-010-0248-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2009] [Accepted: 09/02/2010] [Indexed: 10/19/2022]
Abstract
Silky Fowl is a natural mutant with hyperpigmentation of various internal tissues. Although the mechanism of hyperpigmentation remains unclear, recent studies have shown that the abnormal migration of melanoblast and the absence of environmental barrier molecules are responsible for the hyperpigmentation in Silky Fowl. In this study, 13 genes related to melanocyte development were selected to detect expression changes between Silky Fowl and White Leghorn [including SRY-box 10 (Sox10), paired box (Pax3), stem cell factor (Scf), v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog (Kit), endothelin type-B receptor (Ednrb), endothelin 3 (Edn3), microphthalmia-associated transcription factor (Mitf), tyrosinase (Tyr), tyrosinase-related protein-1 (Trp1), tyrosinase-related protein-2 (Trp2), melanocortin-1 receptor (Mc1r), Agouti-related proteins (Agrp), and Proopiomelanocortin (Pomc)]. Transcript expression was detected in 11 stages from 2.5 to 15 days of incubation. In these embryonic periods, Mitf, Kit, Scf, and Agrp expressed earlier in Silky Fowl than in White Leghorn. Sox10, Ednrb, Kit, Mc1r, and Agrp, associating with the proliferation and differentiation of melanoblast, expressed higher (P < 0.05) in Silky Fowl than White Leghorn during 5-6 days of incubation. After day 8 of incubation, Mitf, Tyr, Trp1, Trp2, and Mc1r expressed higher (P < 0.05) in Silky Fowl than White Leghorn, while Agrp expressed higher (P < 0.05) in White Leghorn than Silky Fowl. Moreover, a regulatory network for melanocyte development was constructed based on the expression data. The network predicted novel regulatory relationships and confirmed relationships that have been reported. These results provide biological insight into the molecular mechanism of hyperpigmentation in the Silky Fowl. However, further investigation is needed to confirm these regulatory relationships.
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64
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Fontanesi L, D’Alessandro E, Scotti E, Liotta L, Crovetti A, Chiofalo V, Russo V. Genetic heterogeneity and selection signature at the KIT gene in pigs showing different coat colours and patterns. Anim Genet 2010; 41:478-92. [DOI: 10.1111/j.1365-2052.2010.02054.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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65
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Ernfors P. Cellular origin and developmental mechanisms during the formation of skin melanocytes. Exp Cell Res 2010; 316:1397-407. [PMID: 20211169 DOI: 10.1016/j.yexcr.2010.02.042] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Accepted: 02/28/2010] [Indexed: 11/20/2022]
Abstract
Melanocytes are derived from the neural crest (NC), which are transient multipotent cells arising by delamination from the developing dorsal neural tube. During recent years, signaling systems and molecular mechanisms of melanocyte development have been studied in detail, but the exact diversification of the NC into melanocytes and how they migrate, expand and disperse in the skin have not been fully understood. The recent finding that Schwann cell precursors (SCPs) of the growing nerve represents a stem cell niche from which various cell types, including Schwann cells, endoneural fibroblasts and melanocytes arise has exposed new knowledge on the cellular basis for melanocyte development. This opens for the identification of new factors and reinterpretation of old data on cell fate instructive, proliferative, survival and cell homing factors participating in melanocyte development.
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Affiliation(s)
- Patrik Ernfors
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institute, 17177 Stockholm, Sweden.
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66
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Vanover JC, Spry ML, Hamilton L, Wakamatsu K, Ito S, D’Orazio JA. Stem cell factor rescues tyrosinase expression and pigmentation in discreet anatomic locations in albino mice. Pigment Cell Melanoma Res 2009; 22:827-38. [PMID: 19682281 PMCID: PMC4962694 DOI: 10.1111/j.1755-148x.2009.00617.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The K14-SCF transgenic murine model of variant pigmentation is based on epidermal expression of stem cell factor (SCF) on the C57BL/6J background. In this system, constitutive expression of SCF by epidermal keratinocytes results in retention of melanocytes in the interfollicular basal layer and pigmentation of the epidermis itself. Here, we extend this animal model by developing a compound mutant transgenic amelanotic animal defective at both the melanocortin 1 receptor (Mc1r) and tyrosinase (Tyr) loci. In the presence of K14-Scf, tyrosinase-mutant animals (previously thought incapable of synthesizing melanin) exhibited progressive robust epidermal pigmentation with age in the ears and tails. Furthermore, K14-SCF Tyr(c2j/c2j) animals demonstrated tyrosinase expression and enzymatic activity, suggesting that the c2j Tyr defect can be rescued in part by SCF in the ears and tail. Lastly, UV sensitivity of K14-Scf congenic animals depended mainly on the amount of eumelanin present in the skin. These findings suggest that c-kit signaling can overcome the c2j Tyr mutation in the ears and tails of aging animals and that UV resistance depends on accumulation of epidermal eumelanin.
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Affiliation(s)
- Jillian C. Vanover
- University of Kentucky College of Medicine, Department of Pediatrics, The Markey Cancer Center and the Graduate Center for Toxicology, Department of Molecular and Biomedical Pharmacology 800 Rose Street, Lexington, KY, 40536
| | - Malinda L. Spry
- University of Kentucky College of Medicine, Department of Pediatrics, The Markey Cancer Center and the Graduate Center for Toxicology, Department of Molecular and Biomedical Pharmacology 800 Rose Street, Lexington, KY, 40536
| | - Laura Hamilton
- University of Kentucky College of Medicine, Department of Pediatrics, The Markey Cancer Center and the Graduate Center for Toxicology, Department of Molecular and Biomedical Pharmacology 800 Rose Street, Lexington, KY, 40536
| | - Kazumasa Wakamatsu
- Fujita Health University School of Health Sciences, Toyoake Aichi, 470-1192, Japan
| | - Shosuke Ito
- Fujita Health University School of Health Sciences, Toyoake Aichi, 470-1192, Japan
| | - John A. D’Orazio
- University of Kentucky College of Medicine, Department of Pediatrics, The Markey Cancer Center and the Graduate Center for Toxicology, Department of Molecular and Biomedical Pharmacology 800 Rose Street, Lexington, KY, 40536
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67
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Fontanesi L, Tazzoli M, Russo V, Beever J. Genetic heterogeneity at the bovine KIT gene in cattle breeds carrying different putative alleles at the spotting locus. Anim Genet 2009; 41:295-303. [PMID: 19968642 DOI: 10.1111/j.1365-2052.2009.02007.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
According to classical genetic studies, piebaldism in cattle is largely influenced by the allelic series at the spotting locus (S), which includes the S(H) (Hereford pattern), S(+) (non-spotted) and s (spotted) alleles. The S locus was mapped on bovine chromosome 6 in the region containing the KIT gene. We investigated the KIT gene, analysing its variability and haplotype distribution in cattle of three breeds (Angus, Hereford and Holstein) with different putative alleles (S(+), S(H) and s respectively) at the S locus. Resequencing of a whole of 0.485 Mb revealed 111 polymorphisms. The global nucleotide diversity was 0.087%. Tajima's D-values were negative for all breeds, indicating putative directional selection. Of the 28 inferred haplotypes, only five were observed in the Hereford breed, in which one was the most frequent. Coalescent simulation showed that it is highly unlikely (P < 10E-6) to obtain this low number of haplotypes conditionally on the observed number of segregating SNPs. Therefore, the neutral model could be rejected for the Hereford breed, suggesting that a selection sweep occurred at the KIT locus. Twelve haplotypes were inferred in Holstein and Angus. For these two breeds, the neutral model could not be rejected. High heterogeneity of the KIT gene was confirmed from a phylogenetic analysis. Our results suggest a role of the KIT gene in determining the S(H) allele(s) in the Hereford, but no evidence of selective sweep was obtained in Holstein, suggesting that complex mechanisms (or other genes) might be the cause of the spotted phenotype in this breed.
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Affiliation(s)
- L Fontanesi
- DIPROVAL, Sezione di Allevamenti Zootecnici, Faculty of Agriculture, University of Bologna, Via F.lli Rosselli 107, 42123 Reggio Emilia, Italy.
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Mimeault M, Batra SK. Recent advances on skin-resident stem/progenitor cell functions in skin regeneration, aging and cancers and novel anti-aging and cancer therapies. J Cell Mol Med 2009; 14:116-34. [PMID: 19725922 PMCID: PMC2916233 DOI: 10.1111/j.1582-4934.2009.00885.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Recent advances in skin-resident adult stem/progenitor cell research have revealed that these immature and regenerative cells with a high longevity provide critical functions in maintaining skin homeostasis and repair after severe injuries along the lifespan of individuals. The establishment of the functional properties of distinct adult stem/progenitor cells found in skin epidermis and hair follicles and extrinsic signals from their niches, which are deregulated during their aging and malignant transformation, has significantly improved our understanding on the etiopathogenesis of diverse human skin disorders and cancers. Particularly, enhanced ultraviolet radiation exposure, inflammation and oxidative stress and telomere attrition during chronological aging may induce severe DNA damages and genomic instability in the skin-resident stem/progenitor cells and their progenies. These molecular events may result in the alterations in key signalling components controlling their self-renewal and/or regenerative capacities as well as the activation of tumour suppressor gene products that trigger their growth arrest and senescence or apoptotic death. The progressive decline in the regenerative functions and/or number of skin-resident adult stem/progenitor cells may cause diverse skin diseases with advancing age. Moreover, the photoaging, telomerase re-activation and occurrence of different oncogenic events in skin-resident adult stem/progenitor cells may also culminate in their malignant transformation into cancer stem/progenitor cells and skin cancer initiation and progression. Therefore, the anti-inflammatory and anti-oxidant treatments and stem cell-replacement and gene therapies as well as the molecular targeting of their malignant counterpart, skin cancer-initiating cells offer great promise to treat diverse skin disorders and cancers.
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Affiliation(s)
- Murielle Mimeault
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198-5870, USA.
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Aoki H, Yamada Y, Hara A, Kunisada T. Two distinct types of mouse melanocyte: differential signaling requirement for the maintenance of non-cutaneous and dermal versus epidermal melanocytes. Development 2009; 136:2511-21. [PMID: 19553284 DOI: 10.1242/dev.037168] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Unlike the thoroughly investigated melanocyte population in the hair follicle of the epidermis, the growth and differentiation requirements of the melanocytes in the eye, harderian gland and inner ear - the so-called non-cutaneous melanocytes - remain unclear. In this study, we investigated the in vitro and in vivo effects of the factors that regulate melanocyte development on the stem cells or the precursors of these non-cutaneous melanocytes. In general, a reduction in KIT receptor tyrosine kinase signaling leads to disordered melanocyte development. However, melanocytes in the eye, ear and harderian gland were revealed to be less sensitive to KIT signaling than cutaneous melanocytes. Instead, melanocytes in the eye and harderian gland were stimulated more effectively by endothelin 3 (ET3) or hepatocyte growth factor (HGF) signals than by KIT signaling, and the precursors of these melanocytes expressed the lowest amount of KIT. The growth and differentiation of these non-cutaneous melanocytes were specifically inhibited by antagonists for ET3 and HGF. In transgenic mice induced to express ET3 or HGF in their skin and epithelial tissues from human cytokeratin 14 promoters, the survival and differentiation of non-cutaneous and dermal melanocytes, but not epidermal melanocytes, were enhanced, apparently irrespective of KIT signaling. These results provide a molecular basis for the clear discrimination between non-cutaneous or dermal melanocytes and epidermal melanocytes, a difference that might be important in the pathogenesis of melanocyte-related diseases and melanomas.
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Affiliation(s)
- Hitomi Aoki
- Department of Tissue and Organ Development, Regeneration, and Advanced Medical Science, Gifu University Graduate School of Medicine, Yanagido, Gifu, Japan
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70
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de Wijn RS, Zaal LH, Hennekam RCM, van der Horst CMAM. Familial clustering of giant congenital melanocytic nevi. J Plast Reconstr Aesthet Surg 2009; 63:906-13. [PMID: 19464972 DOI: 10.1016/j.bjps.2009.02.090] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Revised: 11/30/2008] [Accepted: 02/14/2009] [Indexed: 01/19/2023]
Abstract
Giant congenital melanocytic nevus (GCMN) is an infrequently occurring congenital malformation. GCMN generally occurs in isolation but rare familial occurrence points to a genetic background. We present two cases of familial GCMN: one with two affected siblings and another with two affected double second cousins. Familial occurrence of GCMN reported in literature is reviewed and an overview of the embryology and proliferation given, illustrating the plethora of factors that might lead to GCMN formation. The pattern of inheritance is likely not Mendelian and discordance in identical twins and the segmental distribution of lesions suggest a post-zygotic mutation. A polygenic paradominant inheritance best explains the clinically observed transmission pattern. Candidate genes include those influencing neural crest development and melanocyte proliferation.
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Affiliation(s)
- Robert S de Wijn
- Department of Plastic, Reconstructive and Hand Surgery, Academic Medical Centre, University of Amsterdam, The Netherlands.
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71
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Abstract
A common feature of domestic animals is tameness-i.e., they tolerate and are unafraid of human presence and handling. To gain insight into the genetic basis of tameness and aggression, we studied an intercross between two lines of rats (Rattus norvegicus) selected over >60 generations for increased tameness and increased aggression against humans, respectively. We measured 45 traits, including tameness and aggression, anxiety-related traits, organ weights, and levels of serum components in >700 rats from an intercross population. Using 201 genetic markers, we identified two significant quantitative trait loci (QTL) for tameness. These loci overlap with QTL for adrenal gland weight and for anxiety-related traits and are part of a five-locus epistatic network influencing tameness. An additional QTL influences the occurrence of white coat spots, but shows no significant effect on tameness. The loci described here are important starting points for finding the genes that cause tameness in these rats and potentially in domestic animals in general.
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72
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Haase B, Obexer-Ruff G, Dolf G, Rieder S, Burger D, Poncet PA, Gerber V, Howard J, Leeb T. Haematological parameters are normal in dominant white Franches-Montagnes horses carrying a KIT mutation. Vet J 2009; 184:315-7. [PMID: 19362501 DOI: 10.1016/j.tvjl.2009.02.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Revised: 02/05/2009] [Accepted: 02/06/2009] [Indexed: 11/19/2022]
Abstract
The KIT receptor protein-tyrosine kinase plays an important role during embryonic development. Activation of KIT is crucial for the development of various cell lineages such as melanoblasts, stem cells of the haematopoietic system, spermatogonia and intestinal cells of Cajal. In mice, many mutations in the Kit gene cause pigmentation disorders accompanied by pleiotropic effects on blood cells and male fertility. Previous work has demonstrated that dominant white Franches-Montagnes horses carry one copy of the KIT gene with the p.Y717X mutation. The targeted breeding of white horses would be ethically questionable if white horses were known to suffer from anaemia or leukopenia. The present study demonstrates that no statistically significant differences in peripheral blood parameters are detectable between dominant white and solid-coloured Franches-Montagnes horses. The data indicate that KIT mutations may have different effects in mice, pigs, and horses. The KIT p.Y717X mutation does not have a major negative effect on the haematopoietic system of dominant white horses.
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Affiliation(s)
- Bianca Haase
- Institute of Genetics, Vetsuisse-Faculty, University of Berne, Bremgartenstr. 109a, P.O. Box 8466, 3001 Berne, Switzerland
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73
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Efficacy and prognosis of chronic myeloid leukemia treated with imatinib mesylate in a Chinese population. Int J Hematol 2009; 89:445-451. [DOI: 10.1007/s12185-009-0292-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2008] [Revised: 01/18/2009] [Accepted: 03/03/2009] [Indexed: 12/17/2022]
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74
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Zabierowski SE, Herlyn M. Embryonic stem cells as a model for studying melanocyte development. Methods Mol Biol 2009; 584:301-16. [PMID: 19907984 DOI: 10.1007/978-1-60761-369-5_16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Melanocytes are neural crest-derived pigment-producing cells that reside in the inner ear, in the uveal tract, in hair follicles, and in the skin. The main function of melanocytes is to provide pigmentation through melanin production and secretion to the immediate surrounding area. Although much is known about mature melanocyte function and regulation, particularly in the skin, little is known with regard to the signals and gene expression patterns that ensue upon melanocyte development and differentiation from embryonic precursors. The ability to examine these patterns in an in vitro specified setting through the use of embryonic stem cells holds great potential for understanding melanocyte biology. In this chapter, we outline our procedures for the differentiation of human embryonic stem cells toward mature pigment-producing melanocytes that express the appropriate melanocytic markers and home to the epidermal basal layer in 3D skin reconstructs.
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75
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Jiang X, Zhou J, Yuen NK, Corless CL, Heinrich MC, Fletcher JA, Demetri GD, Widlund HR, Fisher DE, Hodi FS. Imatinib targeting of KIT-mutant oncoprotein in melanoma. Clin Cancer Res 2008; 14:7726-32. [PMID: 19047099 DOI: 10.1158/1078-0432.ccr-08-1144] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
PURPOSE Melanoma subtypes based on anatomic location and UV light exposure can be further classified based on genetic alterations recently identified. Mutations and gene amplification in KIT have been described in a significant percentage of mucosal and acral melanomas. We recently reported a patient with metastatic mucosal melanoma harboring a known KIT mutation treated with imatinib mesylate who experienced a major response. Biological effects of KIT inhibition in these melanomas remain poorly understood. We sought to investigate further the effects of imatinib in these melanoma subsets. EXPERIMENTAL DESIGN Mucosal melanoma cells were analyzed for KIT aberrations by genomic sequencing, quantitative PCR, and single nucleotide polymorphism analyses. Imatinib effects were assayed by viability measurements and apoptotic cytotoxicity. Tumor cell lysates were assayed by Western blots to determine effects on multiple signaling pathways after imatinib exposure. RESULTS Mucosal melanoma cells exhibited imatinib sensitivity correlating with KIT mutational status. Imatinib dramatically decreased proliferation and was cytotoxic to a KIT mutated and amplified cell culture. Exposure to drug affected the mitogen-activated protein kinase, phosphatidylinositol 3-kinase/AKT, JAK-STAT, and antiapoptotic pathways. CONCLUSIONS Rational targeting of KIT in melanoma offers a unique and potent clinical opportunity. In vitro analyses revealed major sensitivity to KIT kinase inhibition by imatinib, with potent induction of melanoma cell apoptosis. Biochemical studies identified changes in signaling molecules regulating proliferation and survival responses, which may serve as mediators and/or biomarkers of in vivo treatment efficacy. Pathways affected by KIT inhibition provide a model for understanding components in effective melanoma cell death and insights into targeting for resistance mechanisms.
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Affiliation(s)
- Xiaofeng Jiang
- Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02115, USA
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76
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Kelsh RN, Harris ML, Colanesi S, Erickson CA. Stripes and belly-spots -- a review of pigment cell morphogenesis in vertebrates. Semin Cell Dev Biol 2008; 20:90-104. [PMID: 18977309 DOI: 10.1016/j.semcdb.2008.10.001] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Revised: 08/29/2008] [Accepted: 10/03/2008] [Indexed: 11/27/2022]
Abstract
Pigment patterns in the integument have long-attracted attention from both scientists and non-scientists alike since their natural attractiveness combines with their excellence as models for the general problem of pattern formation. Pigment cells are formed from the neural crest and must migrate to reach their final locations. In this review, we focus on our current understanding of mechanisms underlying the control of pigment cell migration and patterning in diverse vertebrates. The model systems discussed here - chick, mouse, and zebrafish - each provide unique insights into the major morphogenetic events driving pigment pattern formation. In birds and mammals, melanoblasts must be specified before they can migrate on the dorsolateral pathway. Transmembrane receptors involved in guiding them onto this route include EphB2 and Ednrb2 in chick, and Kit in mouse. Terminal migration depends, in part, upon extracellular matrix reorganization by ADAMTS20. Invasion of the ectoderm, especially into the feather germ and hair follicles, requires specific signals that are beginning to be characterized. We summarize our current understanding of the mechanisms regulating melanoblast number and organization in the epidermis. We note the apparent differences in pigment pattern formation in poikilothermic vertebrates when compared with birds and mammals. With more pigment cell types, migration pathways are more complex and largely unexplored; nevertheless, a role for Kit signaling in melanophore migration is clear and indicates that at least some patterning mechanisms may be highly conserved. We summarize the multiple factors thought to contribute to zebrafish embryonic pigment pattern formation, highlighting a recent study identifying Sdf1a as one factor crucial for regulation of melanophore positioning. Finally, we discuss the mechanisms generating a second, metamorphic pigment pattern in adult fish, emphasizing recent studies strengthening the evidence that undifferentiated progenitor cells play a major role in generating adult pigment cells.
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Affiliation(s)
- Robert N Kelsh
- Centre for Regenerative Medicine, Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK.
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77
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Barkho BZ, Munoz AE, Li X, Li L, Cunningham LA, Zhao X. Endogenous matrix metalloproteinase (MMP)-3 and MMP-9 promote the differentiation and migration of adult neural progenitor cells in response to chemokines. Stem Cells 2008; 26:3139-49. [PMID: 18818437 DOI: 10.1634/stemcells.2008-0519] [Citation(s) in RCA: 161] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Adult neurogenesis is regulated by both intrinsic programs and extrinsic stimuli. The enhanced proliferation of adult neural stem/progenitor cells (aNPCs) in the subventricular zone and the migration of neuroblasts toward the ischemic region in adult brains present a unique challenge as well as an opportunity to understand the molecular mechanisms underlying the extrinsic cue-induced neurogenic responses. Matrix metalloproteinases (MMPs) are a family of proteinases known to play a role in extracellular matrix remodeling and cell migration. However, their presence in aNPCs and their potential function in injury-induced aNPC migration remain largely unexplored. Here we demonstrate that in response to two injury-induced chemokines, stromal cell-derived factor 1 (SDF-1) and vascular endothelial growth factor, aNPCs differentiated into migratory cells that expressed increased levels of MMP-3 and MMP-9. Whereas differentiated neuroblasts and a subpopulation of astrocytes migrated toward the chemokines, undifferentiated progenitors did not migrate. Blocking the expression of MMP-3 or MMP-9 in aNPCs interfered with both the differentiation of aNPCs and chemokine-induced cell migration. Thus, endogenous MMPs expressed by aNPCs are important for mediating their neurogenic response to extrinsic signals.
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Affiliation(s)
- Basam Z Barkho
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, New Mexico 87131, USA
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78
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Kumano K, Masuda S, Sata M, Saito T, Lee SY, Sakata-Yanagimoto M, Tomita T, Iwatsubo T, Natsugari H, Kurokawa M, Ogawa S, Chiba S. Both Notch1 and Notch2 contribute to the regulation of melanocyte homeostasis. Pigment Cell Melanoma Res 2008; 21:70-8. [PMID: 18353145 DOI: 10.1111/j.1755-148x.2007.00423.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Notch signaling affects a variety of mammalian stem cells, but there has been limited evidence that a specific Notch molecule regulates adult stem cells. Recently, it was reported that the reduced Notch signaling initiated at the embryonic stage results in a gradual hair graying phenotype after birth. Here we demonstrate that the oral administration of a gamma-secretase inhibitor (GSI) to wild-type adult C57/Bl6 mice led to a gradual increase in gray spots, which remained unchanged for at least 20 weeks after discontinuing the GSI. In GSI-treated mice, there was a severe decrease in unpigmented melanocytes in the bulge/subbulge region where melanocyte stem cells are located. While we confirmed that Notch1+/-Notch2+/- double heterozygous mice with a C57/Bl6 background were born with a normal hair color phenotype and gradually turned gray after the second hair cycle, in the c-kit mutant Wv background, Notch1+/- and Notch2+/- mice had larger white spots on the first appearance of hair than did the Wv/+ mice, which did not change throughout life. Notch1+/-Notch2+/-Wv/+ mice had white hair virtually all over the body at the first appearance of hair and the depigmentation continued to progress thereafter. Using a neural crest organ culture system, GSI blocked the generation of pigmented melanocytes when added to the culture during the period of melanoblast proliferation, but not during the period of differentiation. These observations imply roles of Notch signaling in both development of melanocyte during embryogenesis and maintenance of melanocyte stem cells in adulthood, while the degree of requirement is distinct in these settings: the latter is more sensitive than the former to the reduced Notch signaling. Furthermore, Notch1 and Notch2 cooperates with c-kit signaling during embryogenesis, and they cooperate with each other to regulate melanocyte homeostasis after birth.
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Affiliation(s)
- Keiki Kumano
- Department of Cell Therapy and Transplantation Medicine, University of Tokyo Hospital, Tokyo, Japan
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79
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Belmar-Lopez C, Mancheno-Corvo P, Saornil MA, Baril P, Vassaux G, Quintanilla M, Martin-Duque P. Uveal vs. cutaneous melanoma. Origins and causes of the differences. Clin Transl Oncol 2008; 10:137-42. [PMID: 18321815 DOI: 10.1007/s12094-008-0170-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Melanoma is a malignant tumour derived from melanocytes (dendritic cells originated from the neural crest and capable to produce melanin synthesis) that could be established on the skin or less frequently on the uvea. The cellular origin from both kind of melanoma seems to be the same but the melanocytes migrates to the epithelia for cutaneous melanoma, while for uveal melanoma, they migrate to mesodermic tissues. Despite the common origin, both melanomas show extreme differences in their metastatic potential, clinical response to treatments, immune response and genetic alterations. We will describe some of those differences in this review.
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Affiliation(s)
- Carolina Belmar-Lopez
- Universidad Francisco de Vitoria, Facultad de Ciencias Biosanitarias, Dpto. Biotecnología, Pozuelo de Alarcón, Madrid, Spain
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80
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Hu SCS, Chen GS, Wu CS, Chai CY, Chen WT, Lan CCE. Pigmented eccrine poromas: expression of melanocyte-stimulating cytokines by tumour cells does not always result in melanocyte colonization. J Eur Acad Dermatol Venereol 2008; 22:303-10. [DOI: 10.1111/j.1468-3083.2007.02406.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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81
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Herlyn M, Halaban R, Ronai Z, Schuchter L, Berwick M, Pinkel D. Roadmap for new opportunities in melanoma research. Semin Oncol 2008; 34:566-76. [PMID: 18083380 DOI: 10.1053/j.seminoncol.2007.09.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Investigators representing all major melanoma research areas present an overview of the most important challenges for the field. Four major research areas are covered plus the training of new investigators. For each area we first describe the present status, its strengths and weaknesses, and then outline specific recommendations. In basic research of melanoma, we outline the pertinent issues for melanoma classification, understanding melanocyte development and transformation, melanoma resistance, tumor microenvironment, metastasis, animal models, immune response, and blood and tissue diagnostics. In clinical research we provide an overview of the current challenges and the strategies for characterization, monitoring, and therapy. It will be important to develop strong research and clinical infrastructures by establishing tumor banks, identifying and validating biomarkers, developing new imaging techniques, and increasing multidisciplinary collaboration and communication. To strengthen the field we need to recruit both young and established investigators and foster career development plans that cover all disciplines. Recent research advances provide significant opportunities to have a major impact on this devastating disease. This group provides recommendations for both short- and long-term strategies that build on research strengths and opportunities established by the many members of the research community.
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Affiliation(s)
- Meenhard Herlyn
- Molecular and Cellular Oncogenesis, The Wistar Institute, Philadelphia, PA 19104, USA.
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82
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Sarin KY, Artandi SE. Aging, graying and loss of melanocyte stem cells. ACTA ACUST UNITED AC 2008; 3:212-7. [PMID: 17917134 DOI: 10.1007/s12015-007-0028-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 02/04/2023]
Abstract
Hair graying is one of the prototypical signs of human aging. Maintenance of hair pigmentation is dependent on the presence and functionality of melanocytes, neural crest derived cells which synthesize pigment for growing hair. The melanocytes, themselves, are maintained by a small number of stem cells which reside in the bulge region of the hair follicle. The recent characterization of the melanocyte lineage during aging has significantly accelerated our understanding of how age-related changes in the melanocyte stem cell compartment contribute to hair graying. This review will discuss our current understanding of hair graying, drawing on evidence from human and mouse studies, and consider the contribution of melanocyte stem cells to this process. Furthermore, using the melanocyte lineage as an example, it will discuss common theories of tissue and stem cell aging.
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Affiliation(s)
- Kavita Y Sarin
- Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
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83
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Carlson JA, Linette GP, Aplin A, Ng B, Slominski A. Melanocyte receptors: clinical implications and therapeutic relevance. Dermatol Clin 2007; 25:541-57, viii-ix. [PMID: 17903613 PMCID: PMC2732336 DOI: 10.1016/j.det.2007.06.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The activation or the inhibition of melanocyte-specific receptors offers novel means of augmenting normal melanocyte function, skin color, and photoprotection, or treating melanocytic disorders, namely at this time, metastatic melanoma. Melanocyte-specific receptors include melanocortin-1 (MCR1) and melatonin receptors. Other receptors that play an important role in melanoma progression are G-protein couple receptors such as Frizzled 5 and receptor tyrosine kinases such as c-Kit and hepatocyte growth factor (HGF) receptor. These receptors activate two crucial cell-signaling pathways, RAS/RAF/MEK/ERK and PI3K/AKT, integral to melanoma cell survival, and can serve as targets for therapy of disseminated melanoma. Activation of death receptors is another pathway that can be exploited with targeted therapeutics to control advanced melanoma. This article reviews the current understanding of melanocyte receptors, their agonists and inhibitors, and their potential to treat the melanocytic pathology.
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Affiliation(s)
- J Andrew Carlson
- Division of Dermatopathology and Dermatology, Department of Pathology and Laboratory Medicine, Albany Medical College MC-81, 47 New Scotland Avenue, Albany, NY 12208, USA.
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84
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Kawaguchi A, Chiba K, Tanimura Y, Motohashi T, Aoki H, Takeda T, Hayashi SI, Shimizu K, Kunisada T. Isolation and characterization of Kit-independent melanocyte precursors induced in the skin of Steel factor transgenic mice. Dev Growth Differ 2007; 50:63-9. [DOI: 10.1111/j.1440-169x.2007.00976.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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85
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Itoi M, Tsukamoto N, Yoshida H, Amagai T. Mesenchymal cells are required for functional development of thymic epithelial cells. Int Immunol 2007; 19:953-64. [PMID: 17625108 DOI: 10.1093/intimm/dxm060] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Epithelial-mesenchymal interactions have essential roles in thymus organogenesis. Mesenchymal cells are known to be required for epithelial cell proliferation. However, the contribution of mesenchymal cells to thymic epithelial cell differentiation is still unclear. In the present study, we have investigated the roles of mesenchymal cells in functional development of epithelial cells in the thymus anlage in patch (ph) mutant mice, which have a primarily defect in mesenchymal cells caused by the absence of platelet-derived growth factor receptor alpha expression. In the ph/ph thymus anlage, T cell progenitors migrate normally among the epithelial cells, however, they are severely impaired to proliferate and differentiate to CD25-positive cells. Epithelial cells of the ph/ph thymus anlage show severely impaired proliferation and expression of functional molecules, such as SCF, Delta-like 4 and MHC class II, which have crucial roles in T cell development. Moreover, the cultured ph/ph thymus anlage fails to develop into a mature organ supporting full T cell development. Addition of intact thymic mesenchymal cells to organ culture induces development of the ph/ph thymus anlage. In the cultured lobes, added mesenchymal cells contribute to form not only the capsule but also the meshwork structure mingled with epithelial cells. Our present results strongly suggest the roles of mesenchymal cells in functional development of epithelial cells in thymus organogenesis. In addition, our data suggest that mesenchymal cells are required to create the thymic microenvironment and to maintain epithelial architecture and function.
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Affiliation(s)
- Manami Itoi
- Department of Immunology and Microbiology, Meiji University of Oriental Medicine, Hiyoshi-cho, Nantan, Kyoto 629-0392, Japan.
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86
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Fang D, Leishear K, Nguyen TK, Finko R, Cai K, Fukunaga M, Li L, Brafford PA, Kulp AN, Xu X, Smalley KSM, Herlyn M. Defining the Conditions for the Generation of Melanocytes from Human Embryonic Stem Cells. Stem Cells 2006; 24:1668-77. [PMID: 16574754 DOI: 10.1634/stemcells.2005-0414] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Because of their undifferentiated nature, human embryonic stem cells (hESCs) are an ideal model system for studying both normal human development and the processes that underlie disease. In the current study, we describe an efficient method for differentiating hESCs into a melanocyte population within 4-6 weeks using three growth factors: Wnt3a, endothelin-3, and stem cell factor. The hESC-derived melanocytes expressed melanocyte markers (such as microphthalmia-associated transcription factor and tyrosinase), developed melanosomes, and produced melanin. They retained the melanocyte phenotype during long-term cell culture (>90 days) and, when incorporated into human reconstructed skin, homed to the appropriate location along the basement membrane in the same manner as epidermis-derived melanocytes. They maintained a stable phenotype even after grafting of the reconstructs to immunodeficient mice. Over time in culture, the hESC-derived melanocytes lost expression of telomerase and underwent senescence. In summary, we have shown for the first time the differentiation of hESCs into melanocytes. This method provides a novel in vitro system for studying the development biology of human melanocytes.
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Affiliation(s)
- Dong Fang
- Program of Molecular and Cellular Oncogenesis, The Wistar Institute, Philadelphia, Pennsylvania 19104, USA
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87
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Tosaki H, Kunisada T, Motohashi T, Aoki H, Yoshida H, Kitajima Y. Mice Transgenic for KitV620A: Recapitulation of Piebaldism but not Progressive Depigmentation Seen in Humans with this Mutation. J Invest Dermatol 2006; 126:1111-8. [PMID: 16456533 DOI: 10.1038/sj.jid.5700173] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Piebaldism is an autosomal dominant genetic pigmentary disorder, characterized by congenital white hair and patches located on the forehead, anterior trunk, and extremities. Most piebald patients have a mutation of the KIT gene, which encodes a tyrosine kinase receptor involved in pigment cell development. The white hair and patches of such patients are already completely formed at birth and do not usually expand thereafter. This stability of pigmented spots also applies to Kit(W) and Kitl(Sl) mutant mice. However, two novel cases of piebaldism were reported in 2001, in which both mother and daughter having a novel Val620Ala mutation in their KIT gene showed progressive depigmentation. To prepare an animal model of this mutation, to explore undefined functions of KIT signaling for maintaining pigmented melanocytes in the skin or more specifically the integrity of the melanocyte stem cell system in the postnatal skin, we produced transgenic mice expressing Val620Ala Kit. These mice well mimicked the white spotting pattern of patients; however, no change in this pattern was observed after birth, even after increasing the transgene expression by various means. Here, we report the unexpectedly extremely stable maintenance of the melanocyte stem cell system under stringent conditions for KIT signaling.
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Affiliation(s)
- Hiroko Tosaki
- Department of Dermatology, Gifu University School of Medicine, Gifu 501-1194, Japan
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88
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Reber L, Da Silva CA, Frossard N. Stem cell factor and its receptor c-Kit as targets for inflammatory diseases. Eur J Pharmacol 2006; 533:327-40. [PMID: 16483568 DOI: 10.1016/j.ejphar.2005.12.067] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2005] [Indexed: 10/25/2022]
Abstract
Stem cell factor (SCF), the ligand of the c-Kit receptor, is expressed by various structural and inflammatory cells in the airways. Binding of SCF to c-Kit leads to activation of multiple pathways, including phosphatidyl-inositol-3 (PI3)-kinase, phospholipase C (PLC)-gamma, Src kinase, Janus kinase (JAK)/Signal Transducers and Activators of Transcription (STAT) and mitogen activated protein (MAP) kinase pathways. SCF is an important growth factor for mast cells, promoting their generation from CD34+ progenitor cells. In vitro, SCF induces mast cells survival, adhesion to extracellular matrix and degranulation, leading to expression and release of histamine, pro-inflammatory cytokines and chemokines. SCF also induces eosinophil adhesion and activation. SCF is upregulated in inflammatory conditions both in vitro and in vivo, in human and mice. Inhibition of the SCF/c-Kit pathway leads to significant decrease of histamine levels, mast cells and eosinophil infiltration, interleukin (IL)-4 production and airway hyperresponsiveness in vivo. Taken together, these data suggest that SCF/c-Kit may be a potential therapeutic target for the control of mast cell and eosinophil number and activation in inflammatory diseases.
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Affiliation(s)
- Laurent Reber
- EA 3771 Inflammation and Environment in Asthma, Université Louis Pasteur-Strasbourg-I, Faculté de Pharmacie, Illkirch, France.
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89
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Sharov A, Tobin DJ, Sharova TY, Atoyan R, Botchkarev VA. Changes in different melanocyte populations during hair follicle involution (catagen). J Invest Dermatol 2006; 125:1259-67. [PMID: 16354197 DOI: 10.1111/j.0022-202x.2005.23959.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Melanin synthesis in the hair follicle (HF) is strictly coupled to the growth stage of the hair cycle and is interrupted during follicle regression (catagen) and resting. Using tyrosine-related protein 2 (Trp)2-LacZ transgenic mice as a model, we show that distinct melanocyte subpopulations of the HF display distinct patterns of apoptosis and survival during catagen. Melanocytes located in the outer root sheath express Bcl-2 and are TUNEL-negative. Part of the pigment-producing melanocytes located above the follicular papilla expresses Fas, TUNEL, and is likely to undergo apoptosis, whereas the other part of these melanocytes expresses c-kit, Bcl-2, and becomes visible in the follicular papilla. During late catagen, TUNEL and Ki-67 negative melanocytes expressing Bcl-2 are seen in the secondary germ of the HF. Lack of proliferation in the follicular melanocytes during catagen suggests that secondary hair germ of late catagen HF is most likely repopulated by melanocytes arising from the outer root sheath or follicular papilla of early/mid-catagen HF. Taken together, these data suggest a possible scenario and mechanisms of the remodeling of the follicular pigmentary unit during HF anagen-catagen-telogen transition and may be used for the establishing in vivo models for pharmacological modulation of melanocyte apoptosis and survival during the hair cycle.
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Affiliation(s)
- Andreya Sharov
- Department of Dermatology, Boston University School of Medicine, Boston, Massachusetts, USA
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90
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Motoi T, Ishida T, Kawato A, Motoi N, Fukayama M. Pigmented neurofibroma: review of Japanese patients with an analysis of melanogenesis demonstrating coexpression of c-met protooncogene and microphthalmia-associated transcription factor. Hum Pathol 2005; 36:871-7. [PMID: 16112003 DOI: 10.1016/j.humpath.2005.05.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2004] [Accepted: 05/03/2005] [Indexed: 11/30/2022]
Abstract
Pigmented neurofibroma (PNF) is a rare variant of neurofibroma showing melanin production. To clarify the clinicopathologic features of PNF and to characterize melanogenesis in PNF, 12 cases of PNF were examined in comparison with schwannoma (SCH, n = 16) and neurofibroma (NF, n = 26). The PNF patients were all Japanese including 7 men and 5 women, and patient age ranged from 11 to 71 years (median, 23.5 years). They showed strong a predisposition for neurofibromatosis type 1. Their tumor size was large, and tumors arose from various sites of skin. Histologically, clusters of epithelioid, dendritic, and spindle melanin-producing cells with faint pigmentation had a tendency to locate in deep dermis and subcutis, which seems to be a characteristic pattern of melanogenesis. There was a transition between melanin-producing cells and Schwann cells. Immunohistochemical examination included known melanogenic markers, microphthalmia-associated transcription factor (MITF), which is a key regulator of melanogenesis, and 2 tyrosine kinase receptors, c-Met and c-Kit, which regulate the development of melanocytes. In PNF, melanin-producing cells were S100 (+), MITF (+), Melan-A (+), tyrosinase (+/-), HMB45 (+/-), c-Met (+), and c-Kit (-). Schwann cells were S100 (+), MITF (-), Melan-A (-), tyrosinase (-), HMB45 (-), c-Met (-), and c-Kit (-), and intermediate spindle cells were S100 (+), MITF (+), Melan-A (+), tyrosinase (-), HMB45 (-), c-Met (+), and c-Kit (-). When compared with SCH and NF, MITF was weakly expressed in a part of tumor cells of SCH, whereas no definite staining was found in NF. c-Met expression was very weak in a scattered manner in SCH (10/15 cases) and NF (10/26 cases). These results suggest that PNF is a unique tumor that shows differentiation toward mature melanin production, but ability of melanin synthesis seems to be impaired. There may be a close relationship between up-regulated MITF and c-Met and the peculiar melanogenic nature of PNF, and both of these are useful diagnostic tools for distinguishing PNFs with less melanin production from NFs.
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Affiliation(s)
- Toru Motoi
- Department of Pathology, The University of Tokyo Hospital, Tokyo 113-8655, Japan.
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91
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Nandi S, Akhter MP, Seifert MF, Dai XM, Stanley ER. Developmental and functional significance of the CSF-1 proteoglycan chondroitin sulfate chain. Blood 2005; 107:786-95. [PMID: 16210339 PMCID: PMC1895624 DOI: 10.1182/blood-2005-05-1822] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The primary macrophage growth factor, colony-stimulating factor-1 (CSF-1), is homodimeric and exists in 3 biologically active isoforms: a membrane-spanning, cell-surface glycoprotein (csCSF-1) and secreted glycoprotein (sgCSF-1) and proteoglycan (spCSF-1) isoforms. To investigate the in vivo role of the chondroitin sulfate glycosaminoglycan (GAG) chain of spCSF-1, we created mice that exclusively express, in a normal tissue-specific and developmental manner, either the secreted precursor of spCSF-1 or the corresponding precursor in which the GAG addition site was mutated. The reproductive, hematopoietic tooth eruption and tissue macrophage defects of CSF-1-deficient, osteopetrotic Csf1(op)/Csf1(op) mice were corrected by transgenic expression of the precursors of either sgCSF-1 or spCSF-1. Furthermore, in contrast to the transgene encoding csCSF-1, both failed to completely correct growth retardation, suggesting a role for csCSF-1 in the regulation of body weight. However, spCSF-1, in contrast to sgCSF-1, completely resolved the osteopetrotic phenotype. Furthermore, in transgenic lines expressing different concentrations of sgCSF-1 or spCSF-1, spCSF-1 more efficiently corrected Csf1(op)/Csf1(op) defects of tooth eruption, eyelid opening, macrophage morphology, and B-cell deficiency than sgCSF-1. These results indicate an important role of the CSF-1 chondroitin sulfate proteoglycan in in vivo signaling by secreted CSF-1.
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Affiliation(s)
- Sayan Nandi
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY 10461, USA
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92
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Johansson A, Pielberg G, Andersson L, Edfors-Lilja I. Polymorphism at the porcine Dominant white/KIT locus influence coat colour and peripheral blood cell measures. Anim Genet 2005; 36:288-96. [PMID: 16026338 DOI: 10.1111/j.1365-2052.2005.01320.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have examined the phenotype of different KIT genotypes with regard to coat colour and several blood parameters (erythrocyte numbers and measures, total and differential leucocyte numbers, haematocrit and haemoglobin levels and serum components). The effect of two different iron supplement regimes (one or two iron injections) on the blood parameters was also examined. For a total of 184 cross-bred piglets (different combinations of Hampshire, Landrace and Yorkshire) blood parameters were measured four times during their first month of life, and the KIT genotypes of these and 70 additional cross-bred piglets were determined. Eight different KIT genotypes were identified, which confirms the large allelic diversity at the KIT locus in commercial pig populations. The results showed that pigs with different KIT genotypes differ both in coat colour and in haematological parameters. In general, homozygous Dominant white (I/I) piglets had larger erythrocytes with lower haemoglobin concentration, indicating a mild macrocytic anaemia. The effect of two compared with one iron injection was also most pronounced for the I/I piglets.
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Affiliation(s)
- A Johansson
- Department of Chemistry and Biomedical Science, University of Kalmar, Kalmar, Sweden.
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93
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Wolnicka-Glubisz A, Noonan FP. Neonatal susceptibility to UV induced cutaneous malignant melanoma in a mouse model. Photochem Photobiol Sci 2005; 5:254-60. [PMID: 16465311 DOI: 10.1039/b506974b] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
UV irradiation has multiple effects on skin including erythema, immunosuppression and the induction of keratinocyte-derived skin cancers and cutaneous malignant melanoma (CMM). CMM which arises from damage to the melanocyte, the pigment cell of the skin, is associated in epidemiologic studies with sun-exposure of susceptible populations, especially children. Our experimental studies have supported the concept that the epidemiologically observed susceptibility in children has a biologic basis. Hepatocyte growth factor/scatter factor (HGF/SF) transgenic mice neonatally irradiated with UV produce melanomas which recapitulate human disease in histopathology and molecular pathogenesis. In this model, neonatal UV is necessary and sufficient for melanoma induction although an additional adult dose of UV radiation significantly increased melanoma multiplicity. One hypothesis for the susceptibility of neonatal mice to induction of melanoma is that neonatal skin contains a large number of immature melanocytes which may result in the retention of the consequences of UV damage throughout the lifetime of the animal. An alternate hypothesis is that the immaturity of the neonatal immune system results in tolerance to melanocytic antigens produced by UV exposure, thus permitting the subsequent outgrowth of melanoma. Here, we discuss the current state of knowledge about the differences between adult and neonatal mice in melanocytes and immune maturation as possible factors playing a role in the susceptibility to melanoma in UV irradiated HGF/SF transgenic mice.
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Affiliation(s)
- Agnieszka Wolnicka-Glubisz
- Department of Environmental and Occupational Health, School of Public Health and Health Services, the George Washington University Medical Center, 2300 Eye Street, NW, Ross Hall, Rm. 110, Washington DC 20037, USA.
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94
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Tobiishi M, Haratake A, Kaminaga H, Nakahara M, Komiya A, Koishikawa H, Uchiwa H, Kawa Y, Mizoguchi M. Changes in responses of UVB irradiated skin of brownish guinea pigs with aging. ACTA ACUST UNITED AC 2005; 18:278-84. [PMID: 16029421 DOI: 10.1111/j.1600-0749.2005.00246.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
It is known that skin often shows irregular pigmentation during aging, which is frequently associated with hyperpigmentation. Many studies have utilized brownish A1 guinea pigs to investigate the pathogenesis of ultraviolet B (UVB)-induced skin pigmentation, however, responses associated with aging following UVB irradiation have not been elucidated. To characterize those responses, dorsal skin of A1 guinea pigs from 14-weeks to 5-yr old were investigated. The minimal erythema dose was found to increase with aging. Further, in pigmentation induced by UVB radiation, skin brightness (DeltaL*-value) decreased equally in both the 14-week old (young) group and in the 3-yr old (old) group of guinea pigs. The DeltaL*-value recovered in the young group from 21 d after UVB irradiation, whereas no such recovery was seen in the old group. In addition, the amount of melanin and the number of melanocytes returned near pre-irradiation levels in the young group, while they remained high in the old group. Our results therefore demonstrate for the first time that skin responses following UVB irradiation change with aging in A1 guinea pigs.
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Affiliation(s)
- Megumi Tobiishi
- Basic Research Laboratory, Kanebo Cosmetics Inc., Odawara, Kanagawa, Japan.
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95
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Klein OD, Cotter PD, Schmidt AM, Bick DP, Tidyman WE, Albertson DG, Pinkel D, Rauen KA. Interstitial deletion of chromosome 12q: Genotype-phenotype correlation of two patients utilizing array comparative genomic hybridization. Am J Med Genet A 2005; 138:349-54. [PMID: 16200635 DOI: 10.1002/ajmg.a.30867] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Interstitial deletions of chromosome 12q are rare, with only 11 reported cases in the literature. We recently described two cases with cytogenetically identical interstitial deletions of the long arm of chromosome 12. Here, we report on a third patient, a 26-month-old male with a cytogenetically-identical interstitial deletion: 46,XY,del(12)(q21.2q22). Phenotypic features of this male proband included craniofacial and ectodermal anomalies, genitourinary anomalies, minor cardiac abnormalities, mild ventriculomegaly on brain MRI, hyperopia, and developmental delay. To further define the extent of the chromosomal aberration, microarray-based comparative genomic hybridization (array CGH) analysis was performed and the array data was compared to one of our previously reported cases. Although cytogenetic analysis of the two patients was concordant, molecular analysis by array CGH revealed that the patients had discordant distal breakpoints. The determination of molecular breakpoints and phenotypic analyses in these two patients, in conjunction with previously reported cases, leads us to propose a 12q deletion phenotype and a possible genetic locus for hyperkeratosis pilaris/ulerythema ophryogenes.
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Affiliation(s)
- Ophir D Klein
- Department of Pediatrics, Division of Medical Genetics, University of California San Francisco, San Francisco, California 94115, USA
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96
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Abstract
The neural crest (NC) yields pluripotent cells endowed with migratory properties. They give rise to neurons, glia, melanocytes and endocrine cells, and to diverse 'mesenchymal' derivatives. Experiments in avian embryos have revealed that the differentiation of the NC 'neural' precursors is strongly influenced by environmental cues. The reversibility of differentiated cells (such as melanocytes or glia) to a pluripotent precursor state can even be induced in vitro by a cytokine, endothelin 3. The fate of 'mesenchymal' NC precursors is strongly restricted by Hox gene expression. In this context, however, facial skeleton morphogenesis is under the control of a multistep crosstalk between the epithelia (endoderm and ectoderm) and NC cells.
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Affiliation(s)
- Nicole M Le Douarin
- Institut d'Embryologie cellulaire et moléculaire du CNRS et du Collège de France (UMR CNRS 7128), 94736 Nogent-sur-Marne, France.
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97
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Yashpal NK, Li J, Wang R. Characterization of c-Kit and nestin expression during islet cell development in the prenatal and postnatal rat pancreas. Dev Dyn 2004; 229:813-25. [PMID: 15042705 DOI: 10.1002/dvdy.10496] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
It has been well documented that there are abundant endocrine progenitor cells in the neonatal pancreas. However, little is known of their relative proportions or even their phenotypes. The aim of this study was to examine the normal distribution and characteristics of putative endocrine precursor cells, identified by c-Kit or nestin expression, within the prenatal and postnatal rat pancreas during islet cell development. Here, we provide evidence of the existence of a subset of ductal, islet, and acinar cells with an immature morphology and high proliferative capacity that expressed c-Kit or nestin. The proportion of islet cells expressing c-Kit or nestin was highest at embryonic day 18 (25 +/- 4% and 28 +/- 6%) and decreased significantly by postnatal day 28 (P < 0.01), 1.3 +/- 0.2% and 5.7 +/- 1%, respectively. The expression of nestin mRNA decreased throughout development, while c-Kit mRNA expression was found to slightly increase in the developing pancreas. Coexpression patterns indicated that c-Kit and nestin form two distinct cell populations in the postnatal pancreas, and infrequently coexpress with other pancreatic cell-specific markers. Furthermore, decreased c-Kit and nestin expression in the islets in postnatal life correlated with an increase in cells immunopositive for Pdx-1 compared with birth (36 +/- 5% vs. 60 +/- 3%, P < 0.01), which accompanied a doubling in the proportion of Glut-2-positive cells (39.4 +/- 4% vs. 68.8 +/- 3%, P < 0.01), both of which are mature beta-cell markers. Taken together, these findings suggest that c-Kit- and nestin-expressing cells represent endocrine precursor cells that undergo marked changes in population dynamics during the transition from prenatal to postnatal pancreatic development in the rat. Characterization of the phenotype, relative abundance and location of these cells within the developing pancreas is an important step toward creating a strategy for isolating stem cell populations and modeling islet cell differentiation in vitro.
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Affiliation(s)
- Nina Kaur Yashpal
- Department of Physiology and Pharmacology, University of Western Ontario, Lawson Health Research Institute, London, Ontario, Canada
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98
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Van Raamsdonk CD, Fitch KR, Fuchs H, de Angelis MH, Barsh GS. Effects of G-protein mutations on skin color. Nat Genet 2004; 36:961-8. [PMID: 15322542 PMCID: PMC7341985 DOI: 10.1038/ng1412] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2004] [Accepted: 07/13/2004] [Indexed: 12/27/2022]
Abstract
A new class of dominant dark skin (Dsk) mutations discovered in a screen of approximately 30,000 mice is caused by increased dermal melanin. We identified three of four such mutations as hypermorphic alleles of Gnaq and Gna11, which encode widely expressed Galphaq subunits, act in an additive and quantitative manner, and require Ednrb. Interactions between Gq and Kit receptor tyrosine kinase signaling can mediate coordinate or independent control of skin and hair color. Our results provide a mechanism that can explain several aspects of human pigmentary variation and show how polymorphism of essential proteins and signaling pathways can affect a single physiologic system.
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Affiliation(s)
- Catherine D Van Raamsdonk
- Department of Genetics, Stanford University School of Medicine, Stanford, California 94305-5323, USA
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99
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Herron MD, Vanderhooft SL, Smock K, Zhou H, Leachman SA, Coffin C. Proliferative Nodules in Congenital Melanocytic Nevi. Am J Surg Pathol 2004; 28:1017-25. [PMID: 15252307 DOI: 10.1097/01.pas.0000126785.61609.6e] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Congenital melanocytic nevi (CMN) occur in 1% to 2% of newborns, and the risk of malignant melanoma is increased in patients with large CMN. Appearance at birth or later of a nodular or hyperpigmented area within a CMN simulates malignant melanoma and prompts biopsy. Although their clinical and pathologic features seem ominous, proliferative nodules (PNs) typically are benign and may regress, although atypical features cause greater concern. Here we report clinical and pathologic findings with outcome in 10 children who had multiple biopsies of large CMN with PNs. We reviewed 78 separate samples from the 10 patients and classified the 60 PNs according to published criteria. A subset of 30 samples containing both the CMN and a PNs was analyzed for immunohistochemical reactivity for melanocytic (S-100 protein, HMB45, melan-A), lymphocytic (CD45), cell-cycle/proliferative (Mib-1, p16, p21, p27, c-Myc), apoptotic (p53, Bax, c-kit, CD95), and anti-apoptotic (bcl-2) markers. Both CMN and PNs had similar expression of melanocytic, lymphocytic, and most cell-cycle/proliferative and apoptotic markers, including Mib-1, p16, p21, p27, c-Myc, Bax, CD95, and bcl-2. A greater proportion of PNs than CMN were reactive for p53 (67% vs. 30%, P < 0.0098) and c-kit (97% vs. 3%, P < 0.0001). p53 and p21 expression in CMN and all types of PNs were inversely correlated. When ordinary and atypical PNs were compared, the atypical PNs more frequently expressed p53, Mib-1, Bax, and bcl-2, but less frequently expressed p21. The c-kit expression in nearly all PNs and its absence in nearly all CMN is potentially useful for recognition of PN, suggests a delayed melanocytic maturation process in proliferative nodules, and may be likely indicative of their benign nature. p53 reactivity in concert with a lack of p21 up-regulation by immunohistochemistry suggests that a p53 mutation may be present in PN, although the immunohistochemical findings alone cannot exclude possible overexpression of wild-type p53. Regressive, involutional, or maturational changes were observed in sequential samples from 4 patients. No patient developed malignant melanoma or another melanocytic nevus-associated malignancy during the follow-up period. These findings underscore the similarities between PNs and the underlying CMN and suggest that maturational, proliferative, and apoptotic processes are involved in their clinical evolution.
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Affiliation(s)
- Mark D Herron
- Department of Dermatology, University of Utah School of Medicine, 100 North Medical Drive, Salt Lake City, UT 84113, USA
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100
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Abstract
Multiple neural and non-neural cell types arise from the neural crest (NC) in vertebrate embryos. Recent work has provided evidence for multipotent stem cells and intermediate precursors in the early NC cell population as well as in various NC derivatives in embryos and even in adult. Advances have been made towards understanding how cytokines, regulatory genes and cell-cell interactions cooperate to control commitment and differentiation to pigment cells, glia and neurone subtypes. In addition, NC cell fates appeared to be unstable, as differentiated NC cells can reverse to multipotent precursors and transdifferentiate in vitro.
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Affiliation(s)
- Nicole M Le Douarin
- Laboratoire d'Embryologie Cellulaire et Moléculaire, CNRS UMR 7128, 49bis, avenue de la Belle Gabrielle, 94736 Nogent-sur-Marne cedex, France.
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