1
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El Mir J, Nasrallah A, Thézé N, Cario M, Fayyad-Kazan H, Thiébaud P, Rezvani HR. Xenopus as a model system for studying pigmentation and pigmentary disorders. Pigment Cell Melanoma Res 2024. [PMID: 38849973 DOI: 10.1111/pcmr.13178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 04/17/2024] [Accepted: 05/24/2024] [Indexed: 06/09/2024]
Abstract
Human pigmentary disorders encompass a broad spectrum of phenotypic changes arising from disruptions in various stages of melanocyte formation, the melanogenesis process, or the transfer of pigment from melanocytes to keratinocytes. A large number of pigmentation genes associated with pigmentary disorders have been identified, many of them awaiting in vivo confirmation. A more comprehensive understanding of the molecular basis of pigmentary disorders requires a vertebrate animal model where changes in pigmentation are easily observable in vivo and can be combined to genomic modifications and gain/loss-of-function tools. Here we present the amphibian Xenopus with its unique features that fulfill these requirements. Changes in pigmentation are particularly easy to score in Xenopus embryos, allowing whole-organism based phenotypic screening. The development and behavior of Xenopus melanocytes closely mimic those observed in mammals. Interestingly, both Xenopus and mammalian skins exhibit comparable reactions to ultraviolet radiation. This review highlights how Xenopus constitutes an alternative and complementary model to the more commonly used mouse and zebrafish, contributing to the advancement of knowledge in melanocyte cell biology and related diseases.
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Affiliation(s)
- Joudi El Mir
- University of Bordeaux, Inserm, BRIC, UMR 1312, Bordeaux, France
| | - Ali Nasrallah
- University of Bordeaux, Inserm, BRIC, UMR 1312, Bordeaux, France
| | - Nadine Thézé
- University of Bordeaux, Inserm, BRIC, UMR 1312, Bordeaux, France
| | - Muriel Cario
- University of Bordeaux, Inserm, BRIC, UMR 1312, Bordeaux, France
- Aquiderm, University of Bordeaux, Bordeaux, France
| | - Hussein Fayyad-Kazan
- Laboratory of Cancer Biology and Molecular Immunology, Lebanese University, Hadath, Lebanon
| | - Pierre Thiébaud
- University of Bordeaux, Inserm, BRIC, UMR 1312, Bordeaux, France
| | - Hamid-Reza Rezvani
- University of Bordeaux, Inserm, BRIC, UMR 1312, Bordeaux, France
- Aquiderm, University of Bordeaux, Bordeaux, France
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2
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Paus R, Sevilla A, Grichnik JM. Human Hair Graying Revisited: Principles, Misconceptions, and Key Research Frontiers. J Invest Dermatol 2024; 144:474-491. [PMID: 38099887 DOI: 10.1016/j.jid.2023.09.276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/09/2023] [Accepted: 09/12/2023] [Indexed: 02/25/2024]
Abstract
Hair graying holds psychosocial importance and serves as an excellent model for studying human pigmentation and aging in an accessible miniorgan. Current evidence suggests that graying results from an interindividually varying mixture of cumulative oxidative and DNA damage, excessive mTORC1 activity, melanocyte senescence, and inadequate production of pigmentation-promoting factors in the hair matrix. Various regulators modulate this process, including genetic factors (DNA repair defects and IRF4 sequence variation, peripheral clock genes, P-cadherin signaling, neuromediators, HGF, KIT ligand secretion, and autophagic flux. This leads to reduced MITF- and tyrosinase-controlled melanogenesis, defective melanosome transfer to precortical matrix keratinocytes, and eventual depletion of hair follicle (HF) pigmentary unit (HFPU) melanocytes and their local progenitors. Graying becomes irreversible only when bulge melanocyte stem cells are also depleted, occurring later in this process. Distinct pigmentary microenvironments are created as the HF cycles: early anagen is the most conducive phase for melanocytic reintegration and activation, and only during anagen can the phenotype of hair graying and repigmentation manifest, whereas the HFPU disassembles during catagen. The temporary reversibility of graying is highlighted by several drugs and hormones that induce repigmentation, indicating potential target pathways. We advise caution in directly applying mouse model concepts, define major open questions, and discuss future human antigraying strategies.
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Affiliation(s)
- Ralf Paus
- Dr. Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA; CUTANEON - Skin & Hair Innovations, Hamburg, Germany; Monasterium Laboratory, Münster, Germany.
| | - Alec Sevilla
- Dr. Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA; Department of Internal Medicine, Lakeland Regional Health, Lakeland, Florida, USA
| | - James M Grichnik
- Department of Dermatology & Cutaneous Surgery, University of South Florida, Tampa, Florida, USA
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3
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Abstract
Over the past decade, melanoma has led the field in new cancer treatments, with impressive gains in on-treatment survival but more modest improvements in overall survival. Melanoma presents heterogeneity and transcriptional plasticity that recapitulates distinct melanocyte developmental states and phenotypes, allowing it to adapt to and eventually escape even the most advanced treatments. Despite remarkable advances in our understanding of melanoma biology and genetics, the melanoma cell of origin is still fiercely debated because both melanocyte stem cells and mature melanocytes can be transformed. Animal models and high-throughput single-cell sequencing approaches have opened new opportunities to address this question. Here, we discuss the melanocytic journey from the neural crest, where they emerge as melanoblasts, to the fully mature pigmented melanocytes resident in several tissues. We describe a new understanding of melanocyte biology and the different melanocyte subpopulations and microenvironments they inhabit, and how this provides unique insights into melanoma initiation and progression. We highlight recent findings on melanoma heterogeneity and transcriptional plasticity and their implications for exciting new research areas and treatment opportunities. The lessons from melanocyte biology reveal how cells that are present to protect us from the damaging effects of ultraviolet radiation reach back to their origins to become a potentially deadly cancer.
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Affiliation(s)
- Patricia P Centeno
- Molecular Oncology Group, Cancer Research UK Manchester Institute, The University of Manchester, Alderley Park, UK
| | - Valeria Pavet
- Molecular Oncology Group, Cancer Research UK Manchester Institute, The University of Manchester, Alderley Park, UK
| | - Richard Marais
- Molecular Oncology Group, Cancer Research UK Manchester Institute, The University of Manchester, Alderley Park, UK.
- Oncodrug Ltd, Alderly Park, Macclesfield, UK.
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4
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Zhang X, Zhu J, Zhang J, Zhao H. Melanocyte stem cells and hair graying. J Cosmet Dermatol 2023; 22:1720-1723. [PMID: 36853923 DOI: 10.1111/jocd.15652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 12/27/2022] [Accepted: 01/13/2023] [Indexed: 03/01/2023]
Abstract
OBJECTIVES To explore the relationship between melanocyte stem cells in the hair follicle bulge and hair graying so as to fully understand their key role in the pathogenesis of hair graying. METHODS The published articles about "hair graying, hair color, pigmentation disorders" and "melanocyte stem cells, melanocyte" were searched and analyzed in PubMed to explore their relationship. RESULTS Melanocytes in hair bulb are involved in the pathogenesis of hair graying as well as the melanocyte stem cells in hair follicle bulge also play important roles in the formation of hair graying through some ways. CONCLUSION Loss of melanocyte stem cells in hair follicle bulge is one of the main reasons of hair graying, and more researches are needed to explain the underlying mechanisms of ectopic differentiation of melanocyte stem cells in different individual.
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Affiliation(s)
- Xiaojiao Zhang
- Department of Dermatology, University-Town Hospital of Chongqing Medical University, Chongqing, China
| | - Jinyu Zhu
- Department of Dermatology, University-Town Hospital of Chongqing Medical University, Chongqing, China
| | - Jiezhi Zhang
- Department of Dermatology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Hengguang Zhao
- Department of Dermatology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
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5
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Fernandes B, Cavaco-Paulo A, Matamá T. A Comprehensive Review of Mammalian Pigmentation: Paving the Way for Innovative Hair Colour-Changing Cosmetics. BIOLOGY 2023; 12:biology12020290. [PMID: 36829566 PMCID: PMC9953601 DOI: 10.3390/biology12020290] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/26/2023] [Accepted: 02/09/2023] [Indexed: 02/15/2023]
Abstract
The natural colour of hair shafts is formed at the bulb of hair follicles, and it is coupled to the hair growth cycle. Three critical processes must happen for efficient pigmentation: (1) melanosome biogenesis in neural crest-derived melanocytes, (2) the biochemical synthesis of melanins (melanogenesis) inside melanosomes, and (3) the transfer of melanin granules to surrounding pre-cortical keratinocytes for their incorporation into nascent hair fibres. All these steps are under complex genetic control. The array of natural hair colour shades are ascribed to polymorphisms in several pigmentary genes. A myriad of factors acting via autocrine, paracrine, and endocrine mechanisms also contributes for hair colour diversity. Given the enormous social and cosmetic importance attributed to hair colour, hair dyeing is today a common practice. Nonetheless, the adverse effects of the long-term usage of such cosmetic procedures demand the development of new methods for colour change. In this context, case reports of hair lightening, darkening and repigmentation as a side-effect of the therapeutic usage of many drugs substantiate the possibility to tune hair colour by interfering with the biology of follicular pigmentary units. By scrutinizing mammalian pigmentation, this review pinpoints key targetable processes for the development of innovative cosmetics that can safely change the hair colour from the inside out.
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Affiliation(s)
- Bruno Fernandes
- CEB—Centre of Biological Engineering, University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal
| | - Artur Cavaco-Paulo
- CEB—Centre of Biological Engineering, University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal
- LABBELS—Associate Laboratory, 4710-057 Braga, Portugal
- Correspondence: (A.C.-P.); (T.M.); Tel.: +351-253-604-409 (A.C.-P.); +351-253-601-599 (T.M.)
| | - Teresa Matamá
- CEB—Centre of Biological Engineering, University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal
- LABBELS—Associate Laboratory, 4710-057 Braga, Portugal
- Correspondence: (A.C.-P.); (T.M.); Tel.: +351-253-604-409 (A.C.-P.); +351-253-601-599 (T.M.)
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6
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Sittewelle M, Kappès V, Zhou C, Lécuyer D, Monsoro-Burq AH. PFKFB4 interacts with ICMT and activates RAS/AKT signaling-dependent cell migration in melanoma. Life Sci Alliance 2022; 5:5/12/e202201377. [PMID: 35914811 PMCID: PMC9348664 DOI: 10.26508/lsa.202201377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 07/04/2022] [Accepted: 07/06/2022] [Indexed: 11/24/2022] Open
Abstract
Glycolysis regulator PFKFB4 promotes cell migration in metastatic melanoma and normal melanocytes by a non-conventional glycolysis-independent function involving ICMT, RAS, and AKT signaling. Cell migration is a complex process, tightly regulated during embryonic development and abnormally activated during cancer metastasis. RAS-dependent signaling is a major nexus controlling essential cell parameters including proliferation, survival, and migration, utilizing downstream effectors such as the PI3K/AKT signaling pathway. In melanoma, oncogenic mutations frequently enhance RAS, PI3K/AKT, or MAP kinase signaling and trigger other cancer hallmarks among which the activation of metabolism regulators. PFKFB4 is one of these critical regulators of glycolysis and of the Warburg effect. Here, however, we explore a novel function of PFKFB4 in melanoma cell migration. We find that PFKFB4 interacts with ICMT, a posttranslational modifier of RAS. PFKFB4 promotes ICMT/RAS interaction, controls RAS localization at the plasma membrane, activates AKT signaling and enhances cell migration. We thus provide evidence of a novel and glycolysis-independent function of PFKFB4 in human cancer cells. This unconventional activity links the metabolic regulator PFKFB4 to RAS-AKT signaling and impacts melanoma cell migration.
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Affiliation(s)
- Méghane Sittewelle
- Université Paris-Saclay, Faculté des Sciences d'Orsay, CNRS UMR 3347, INSERM U1021, Orsay, France.,Institut Curie Research Division, PSL Research University, CNRS UMR 3347, INSERM U1021, Orsay, France
| | - Vincent Kappès
- Université Paris-Saclay, Faculté des Sciences d'Orsay, CNRS UMR 3347, INSERM U1021, Orsay, France.,Institut Curie Research Division, PSL Research University, CNRS UMR 3347, INSERM U1021, Orsay, France
| | - Chenxi Zhou
- Université Paris-Saclay, Faculté des Sciences d'Orsay, CNRS UMR 3347, INSERM U1021, Orsay, France.,Institut Curie Research Division, PSL Research University, CNRS UMR 3347, INSERM U1021, Orsay, France
| | - Déborah Lécuyer
- Université Paris-Saclay, Faculté des Sciences d'Orsay, CNRS UMR 3347, INSERM U1021, Orsay, France.,Institut Curie Research Division, PSL Research University, CNRS UMR 3347, INSERM U1021, Orsay, France
| | - Anne H Monsoro-Burq
- Université Paris-Saclay, Faculté des Sciences d'Orsay, CNRS UMR 3347, INSERM U1021, Orsay, France .,Institut Curie Research Division, PSL Research University, CNRS UMR 3347, INSERM U1021, Orsay, France
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7
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Jo SK, Lee JY, Lee Y, Kim CD, Lee JH, Lee YH. Three Streams for the Mechanism of Hair Graying. Ann Dermatol 2018; 30:397-401. [PMID: 30065578 PMCID: PMC6029974 DOI: 10.5021/ad.2018.30.4.397] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 03/09/2018] [Indexed: 02/06/2023] Open
Abstract
Hair graying is an obvious sign of human aging. Although graying has been investigated extensively, the mechanism remains unclear. Here, we reviewed previous studies on the mechanism of graying and seek to offer some new insights. The traditional view is that hair graying is caused by exhaustion of the pigmentary potential of the melanocytes of hair bulbs. Melanocyte dysfunction may be attributable to the effects of toxic reactive oxygen species on melanocyte nuclei and mitochondria. A recent study suggests that bulge melanocyte stem cells (MSCs) are the key cells in play. Graying may be caused by defective MSC self-maintenance, not by any deficiency in bulbar melanocytes. Our previous study suggested that graying may be principally attributable to active hair growth. Active hair growth may produce oxidative or genotoxic stress in hair bulge. These internal stress may cause eventually depletion of MSC in the hair follicles. Taken together, hair graying may be caused by MSC depletion by genotoxic stress in the hair bulge. Hair graying may also be sometimes caused by dysfunction of the melanocytes by oxidative stress in the hair bulb. In addition, hair graying may be attributable to MSC depletion by active hair growth.
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Affiliation(s)
- Seong Kyeong Jo
- Department of Anatomy, Chungnam National University College of Medicine, Daejeon, Korea
| | - Ji Yeon Lee
- Department of Anatomy, Chungnam National University College of Medicine, Daejeon, Korea
| | - Young Lee
- Department of Dermatology, Chungnam National University College of Medicine, Daejeon, Korea
| | - Chang Deok Kim
- Department of Dermatology, Chungnam National University College of Medicine, Daejeon, Korea
| | - Jeung-Hoon Lee
- Department of Dermatology, Chungnam National University College of Medicine, Daejeon, Korea
| | - Young Ho Lee
- Department of Anatomy, Chungnam National University College of Medicine, Daejeon, Korea
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8
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A direct link between MITF, innate immunity, and hair graying. PLoS Biol 2018; 16:e2003648. [PMID: 29723194 PMCID: PMC5933715 DOI: 10.1371/journal.pbio.2003648] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 03/30/2018] [Indexed: 12/03/2022] Open
Abstract
Melanocyte stem cells (McSCs) and mouse models of hair graying serve as useful systems to uncover mechanisms involved in stem cell self-renewal and the maintenance of regenerating tissues. Interested in assessing genetic variants that influence McSC maintenance, we found previously that heterozygosity for the melanogenesis associated transcription factor, Mitf, exacerbates McSC differentiation and hair graying in mice that are predisposed for this phenotype. Based on transcriptome and molecular analyses of Mitfmi-vga9/+ mice, we report a novel role for MITF in the regulation of systemic innate immune gene expression. We also demonstrate that the viral mimic poly(I:C) is sufficient to expose genetic susceptibility to hair graying. These observations point to a critical suppressor of innate immunity, the consequences of innate immune dysregulation on pigmentation, both of which may have implications in the autoimmune, depigmenting disease, vitiligo. Hair pigmentation over the course of a lifetime depends on melanocyte stem cells that reside in the hair follicle. As old hairs fall out and new hairs grow in, melanocyte stem cells serve as a reservoir for the melanocytes that produce the pigment that gives hair its visible color. The loss of these stem cells leads to the growth of nonpigmented, or gray, hairs. Evaluating mouse models of hair graying can reveal key aspects of melanocyte stem cell biology. Using this approach, we discovered a novel role for the melanogenesis associated transcription factor, MITF, in repressing the expression of innate immune genes within cells of the melanocyte lineage. The importance of this repression is revealed in animals that have a predisposition for hair graying. In these animals, artificial elevation of the innate immune response, either through a genetic mechanism or via exposure to viral mimic, results in significant melanocyte and melanocyte stem cell loss and leads to the production of an increased number of gray hairs. These observations highlight the negative effects of innate immune activation on melanocyte and melanocyte stem cell physiology and suggest a connection between viral infection and hair graying.
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9
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Li H, Hou L. Regulation of melanocyte stem cell behavior by the niche microenvironment. Pigment Cell Melanoma Res 2018; 31:556-569. [PMID: 29582573 DOI: 10.1111/pcmr.12701] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 03/05/2018] [Indexed: 12/17/2022]
Abstract
Somatic stem cells are regulated by their niches to maintain tissue homeostasis and repair throughout the lifetime of an organism. An excellent example to study stem cell/niche interactions is provided by the regeneration of melanocytes during the hair cycle and in response to various types of injury. These processes are regulated by neighboring stem cells and multiple signaling pathways, including WNT/β-catenin, KITL/KIT, EDNs/EDNRB, TGF-β/TGF-βR, α-MSH/MC1R, and Notch signaling. In this review, we highlight recent studies that have advanced our understanding of the molecular crosstalk between melanocyte stem cells and their neighboring cells, which collectively form the niche microenvironment, and we focus on the question of how McSCs/niche interactions shape the responses to genotoxic damages and mechanical injury.
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Affiliation(s)
- Huirong Li
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Ling Hou
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Ophthalmology, Optometry and Vision Science and Key Laboratory of Vision Science of Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology, Wenzhou Medical University, Wenzhou, China
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10
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Druillennec S, Pouponnot C, Eychène A. NRAS-driven melanoma: A RAF can hide another. Mol Cell Oncol 2017; 4:e1344758. [PMID: 29209643 PMCID: PMC5706944 DOI: 10.1080/23723556.2017.1344758] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 06/15/2017] [Accepted: 06/16/2017] [Indexed: 10/26/2022]
Abstract
Using mouse genetics, we recently showed that BRAF has a critical role in initiation of NRAS-driven melanoma that cannot be compensated by CRAF. In contrast, RAF proteins display compensatory functions in fully established tumors and ARAF can sustain proliferation in the absence of BRAF and CRAF, highlighting an addiction to RAF signaling in NRAS-driven melanoma.
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Affiliation(s)
- Sabine Druillennec
- Institut Curie, Orsay, France.,INSERM U1021, Centre Universitaire, Orsay, France.,CNRS UMR 3347, Centre Universitaire, Orsay, France.,Université Paris Sud-11, Orsay, France.,Equipe Labellisée Ligue Nationale Contre le Cancer
| | - Celio Pouponnot
- Institut Curie, Orsay, France.,INSERM U1021, Centre Universitaire, Orsay, France.,CNRS UMR 3347, Centre Universitaire, Orsay, France.,Université Paris Sud-11, Orsay, France.,Equipe Labellisée Ligue Nationale Contre le Cancer
| | - Alain Eychène
- Institut Curie, Orsay, France.,INSERM U1021, Centre Universitaire, Orsay, France.,CNRS UMR 3347, Centre Universitaire, Orsay, France.,Université Paris Sud-11, Orsay, France.,Equipe Labellisée Ligue Nationale Contre le Cancer
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11
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Dorard C, Estrada C, Barbotin C, Larcher M, Garancher A, Leloup J, Beermann F, Baccarini M, Pouponnot C, Larue L, Eychène A, Druillennec S. RAF proteins exert both specific and compensatory functions during tumour progression of NRAS-driven melanoma. Nat Commun 2017; 8:15262. [PMID: 28497782 PMCID: PMC5437303 DOI: 10.1038/ncomms15262] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 03/14/2017] [Indexed: 12/19/2022] Open
Abstract
NRAS and its effector BRAF are frequently mutated in melanoma. Paradoxically, CRAF but not BRAF was shown to be critical for various RAS-driven cancers, raising the question of the role of RAF proteins in NRAS-induced melanoma. Here, using conditional ablation of Raf genes in NRAS-induced mouse melanoma models, we investigate their contribution in tumour progression, from the onset of benign tumours to malignant tumour maintenance. We show that BRAF expression is required for ERK activation and nevi development, demonstrating a critical role in the early stages of NRAS-driven melanoma. After melanoma formation, single Braf or Craf ablation is not sufficient to block tumour growth, showing redundant functions for RAF kinases. Finally, proliferation of resistant cells emerging in the absence of BRAF and CRAF remains dependent on ARAF-mediated ERK activation. These results reveal specific and compensatory functions for BRAF and CRAF and highlight an addiction to RAF signalling in NRAS-driven melanoma. The melanoma-driver mutations in NRAS and BRAF are mutually exclusive but the contribution of RAF signalling downstream of NRAS remains to be clarified. Here, using mouse models, the authors show specific roles of each member of the RAF family at different stages of melanomagenesis.
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Affiliation(s)
- Coralie Dorard
- Institut Curie, Orsay F-91405, France.,INSERM U1021, Centre Universitaire, Orsay F-91405, France.,CNRS UMR 3347, Centre Universitaire, Orsay F-91405, France.,Université Paris Sud-11, Orsay F-91405, France.,Equipe Labellisée Ligue Nationale Contre le Cancer, Orsay F-91405, France
| | - Charlène Estrada
- Institut Curie, Orsay F-91405, France.,INSERM U1021, Centre Universitaire, Orsay F-91405, France.,CNRS UMR 3347, Centre Universitaire, Orsay F-91405, France.,Université Paris Sud-11, Orsay F-91405, France.,Equipe Labellisée Ligue Nationale Contre le Cancer, Orsay F-91405, France
| | - Céline Barbotin
- Institut Curie, Orsay F-91405, France.,INSERM U1021, Centre Universitaire, Orsay F-91405, France.,CNRS UMR 3347, Centre Universitaire, Orsay F-91405, France.,Université Paris Sud-11, Orsay F-91405, France.,Equipe Labellisée Ligue Nationale Contre le Cancer, Orsay F-91405, France
| | - Magalie Larcher
- Institut Curie, Orsay F-91405, France.,INSERM U1021, Centre Universitaire, Orsay F-91405, France.,CNRS UMR 3347, Centre Universitaire, Orsay F-91405, France.,Université Paris Sud-11, Orsay F-91405, France.,Equipe Labellisée Ligue Nationale Contre le Cancer, Orsay F-91405, France
| | - Alexandra Garancher
- Institut Curie, Orsay F-91405, France.,INSERM U1021, Centre Universitaire, Orsay F-91405, France.,CNRS UMR 3347, Centre Universitaire, Orsay F-91405, France.,Université Paris Sud-11, Orsay F-91405, France
| | - Jessy Leloup
- Institut Curie, Orsay F-91405, France.,INSERM U1021, Centre Universitaire, Orsay F-91405, France.,CNRS UMR 3347, Centre Universitaire, Orsay F-91405, France.,Université Paris Sud-11, Orsay F-91405, France.,Equipe Labellisée Ligue Nationale Contre le Cancer, Orsay F-91405, France
| | - Friedrich Beermann
- Swiss Institute for Experimental Cancer Research (ISREC), Ecole Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland
| | - Manuela Baccarini
- Max F. Perutz Laboratories, Center for Molecular Biology, University of Vienna, Vienna 1030, Austria
| | - Celio Pouponnot
- Institut Curie, Orsay F-91405, France.,INSERM U1021, Centre Universitaire, Orsay F-91405, France.,CNRS UMR 3347, Centre Universitaire, Orsay F-91405, France.,Université Paris Sud-11, Orsay F-91405, France
| | - Lionel Larue
- Institut Curie, Orsay F-91405, France.,INSERM U1021, Centre Universitaire, Orsay F-91405, France.,CNRS UMR 3347, Centre Universitaire, Orsay F-91405, France.,Université Paris Sud-11, Orsay F-91405, France.,Equipe Labellisée Ligue Nationale Contre le Cancer, Orsay F-91405, France
| | - Alain Eychène
- Institut Curie, Orsay F-91405, France.,INSERM U1021, Centre Universitaire, Orsay F-91405, France.,CNRS UMR 3347, Centre Universitaire, Orsay F-91405, France.,Université Paris Sud-11, Orsay F-91405, France.,Equipe Labellisée Ligue Nationale Contre le Cancer, Orsay F-91405, France
| | - Sabine Druillennec
- Institut Curie, Orsay F-91405, France.,INSERM U1021, Centre Universitaire, Orsay F-91405, France.,CNRS UMR 3347, Centre Universitaire, Orsay F-91405, France.,Université Paris Sud-11, Orsay F-91405, France.,Equipe Labellisée Ligue Nationale Contre le Cancer, Orsay F-91405, France
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12
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Laugier F, Finet-Benyair A, André J, Rachakonda PS, Kumar R, Bensussan A, Dumaz N. RICTOR involvement in the PI3K/AKT pathway regulation in melanocytes and melanoma. Oncotarget 2016; 6:28120-31. [PMID: 26356562 PMCID: PMC4695048 DOI: 10.18632/oncotarget.4866] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 08/17/2015] [Indexed: 01/16/2023] Open
Abstract
Several studies have highlighted the importance of the PI3K pathway in melanocytes and its frequent over-activation in melanoma. However, little is known about regulation of the PI3K pathway in melanocytic cells. We showed that normal human melanocytes are less sensitive to selective PI3K or mTOR inhibitors than to dual PI3K/mTOR inhibitors. The resistance to PI3K inhibitor was due to a rapid AKT reactivation limiting the inhibitor effect on proliferation. Reactivation of AKT was linked to a feedback mechanism involving the mTORC2 complex and in particular its scaffold protein RICTOR. RICTOR overexpression in melanocytes disrupted the negative feedback, activated the AKT pathway and stimulated clonogenicity highlighting the importance of this feedback to restrict melanocyte proliferation. We found that the RICTOR locus is frequently amplified and overexpressed in melanoma and that RICTOR over-expression in NRAS-transformed melanocytes stimulates their clonogenicity, demonstrating that RICTOR amplification can cooperate with NRAS mutation to stimulate melanoma proliferation. These results show that RICTOR plays a central role in PI3K pathway negative feedback in melanocytes and that its deregulation could be involved in melanoma development.
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Affiliation(s)
- Florence Laugier
- INSERM, U976, Centre de Recherche sur la Peau, Hôpital Saint-Louis, Paris, F-75010, France.,Université Paris Diderot, Sorbonne Paris Cité, UMRS976, Paris, F-75010, France
| | - Adeline Finet-Benyair
- INSERM, U976, Centre de Recherche sur la Peau, Hôpital Saint-Louis, Paris, F-75010, France.,Université Paris Diderot, Sorbonne Paris Cité, UMRS976, Paris, F-75010, France
| | - Jocelyne André
- INSERM, U976, Centre de Recherche sur la Peau, Hôpital Saint-Louis, Paris, F-75010, France.,Université Paris Diderot, Sorbonne Paris Cité, UMRS976, Paris, F-75010, France
| | | | - Rajiv Kumar
- Division of Molecular Genetic Epidemiology, German Cancer Research Center, 69120, Heidelberg, Germany
| | - Armand Bensussan
- INSERM, U976, Centre de Recherche sur la Peau, Hôpital Saint-Louis, Paris, F-75010, France.,Université Paris Diderot, Sorbonne Paris Cité, UMRS976, Paris, F-75010, France
| | - Nicolas Dumaz
- INSERM, U976, Centre de Recherche sur la Peau, Hôpital Saint-Louis, Paris, F-75010, France.,Université Paris Diderot, Sorbonne Paris Cité, UMRS976, Paris, F-75010, France
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13
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Conditional Deletion of Kit in Melanocytes: White Spotting Phenotype Is Cell Autonomous. J Invest Dermatol 2015; 135:1829-1838. [DOI: 10.1038/jid.2015.83] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 02/04/2015] [Accepted: 02/15/2015] [Indexed: 12/13/2022]
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14
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Abstract
RAF family kinases were among the first oncoproteins to be described more than 30 years ago. They primarily act as signalling relays downstream of RAS, and their close ties to cancer have fuelled a large number of studies. However, we still lack a systems-level understanding of their regulation and mode of action. The recent discovery that the catalytic activity of RAF depends on an allosteric mechanism driven by kinase domain dimerization is providing a vital new piece of information towards a comprehensive model of RAF function. The fact that current RAF inhibitors unexpectedly induce ERK signalling by stimulating RAF dimerization also calls for a deeper structural characterization of this family of kinases.
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15
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de Iriarte Rodríguez R, Magariños M, Pfeiffer V, Rapp UR, Varela-Nieto I. C-Raf deficiency leads to hearing loss and increased noise susceptibility. Cell Mol Life Sci 2015; 72:3983-98. [PMID: 25975225 PMCID: PMC4575698 DOI: 10.1007/s00018-015-1919-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 04/21/2015] [Accepted: 04/27/2015] [Indexed: 12/20/2022]
Abstract
The family of RAF kinases transduces extracellular information to the nucleus, and their activation is crucial for cellular regulation on many levels, ranging from embryonic development to carcinogenesis. B-RAF and C-RAF modulate neurogenesis and neuritogenesis during chicken inner ear development. C-RAF deficiency in humans is associated with deafness in the rare genetic insulin-like growth factor 1 (IGF-1), Noonan and Leopard syndromes. In this study, we show that RAF kinases are expressed in the developing inner ear and in adult mouse cochlea. A homozygous C-Raf deletion in mice caused profound deafness with no evident cellular aberrations except for a remarkable reduction of the K+ channel Kir4.1 expression, a trait that suffices as a cause of deafness. To explore the role of C-Raf in cellular protection and repair, heterozygous C-Raf+/− mice were exposed to noise. A reduced C-RAF level negatively affected hearing preservation in response to noise through mechanisms involving the activation of JNK and an exacerbated apoptotic response. Taken together, these results strongly support a role for C-RAF in hearing protection.
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Affiliation(s)
- Rocío de Iriarte Rodríguez
- Instituto de Investigaciones Biomédicas "Alberto Sols", CSIC-UAM, Arturo Duperier 4, 28029, Madrid, Spain.,Centre for Biomedical Network Research (CIBERER), Institute of Health Carlos III (ISCIII), Madrid, Spain
| | - Marta Magariños
- Instituto de Investigaciones Biomédicas "Alberto Sols", CSIC-UAM, Arturo Duperier 4, 28029, Madrid, Spain. .,Centre for Biomedical Network Research (CIBERER), Institute of Health Carlos III (ISCIII), Madrid, Spain. .,Departamento de Biología, Universidad Autónoma de Madrid, Darwin 2, 28049, Madrid, Spain.
| | - Verena Pfeiffer
- Institute for Medical Radiation and Cell Research (MSZ), University of Würzburg, Versbacher Strasse 5, 97078, Würzburg, Germany.,Institute for Anatomy and Cell Biology, University of Würzburg, Koellikerstraße 6, 97070, Würzburg, Germany
| | - Ulf R Rapp
- Institute for Medical Radiation and Cell Research (MSZ), University of Würzburg, Versbacher Strasse 5, 97078, Würzburg, Germany.,Molecular Mechanisms of Lung Cancer, Max Planck Institute for Heart and Lung Research, Parkstr. 1, 61231, Bad Nauheim, Germany
| | - Isabel Varela-Nieto
- Instituto de Investigaciones Biomédicas "Alberto Sols", CSIC-UAM, Arturo Duperier 4, 28029, Madrid, Spain.,Centre for Biomedical Network Research (CIBERER), Institute of Health Carlos III (ISCIII), Madrid, Spain.,Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain
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16
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Abstract
Melanocyte development provides an excellent model for studying more complex developmental processes. Melanocytes have an apparently simple aetiology, differentiating from the neural crest and migrating through the developing embryo to specific locations within the skin and hair follicles, and to other sites in the body. The study of pigmentation mutations in the mouse provided the initial key to identifying the genes and proteins involved in melanocyte development. In addition, work on chicken has provided important embryological and molecular insights, whereas studies in zebrafish have allowed live imaging as well as genetic and transgenic approaches. This cross-species approach is powerful and, as we review here, has resulted in a detailed understanding of melanocyte development and differentiation, melanocyte stem cells and the role of the melanocyte lineage in diseases such as melanoma. Summary: This Review discusses melanocyte development and differentiation, melanocyte stem cells, and the role of the melanocyte lineage in diseases such as melanoma.
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Affiliation(s)
| | - Ian J Jackson
- MRC Human Genetics Unit and University of Edinburgh Cancer Research UK Cancer Centre, MRC Institute for Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - E Elizabeth Patton
- MRC Human Genetics Unit and Roslin Institute, University of Edinburgh, Edinburgh EH25 9RG, UK
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17
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Harris ML, Levy DJ, Watkins-Chow DE, Pavan WJ. Ectopic differentiation of melanocyte stem cells is influenced by genetic background. Pigment Cell Melanoma Res 2015; 28:223-8. [PMID: 25495036 DOI: 10.1111/pcmr.12344] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 12/01/2014] [Indexed: 01/13/2023]
Abstract
Hair graying in mouse is attributed to the loss of melanocyte stem cell function and the progressive depletion of the follicular melanocyte population. Single-gene, hair graying mouse models have pointed to a number of critical pathways involved in melanocyte stem cell biology; however, the broad range of phenotypic variation observed in human hair graying suggests that additional genetic variants involved in this process may yet be discovered. Using a sensitized approach, we ask here whether natural genetic variation influences a predominant cellular mechanism of hair graying in mouse, melanocyte stem cell differentiation. We developed an innovative method to quantify melanocyte stem cell differentiation by measuring ectopically pigmented melanocyte stem cells in response to the melanocyte-specific transgene Tg(Dct-Sox10). We make the novel observation that the production of ectopically pigmented melanocyte stem cells varies considerably across strains. The success of sensitizing for melanocyte stem cell differentiation by Tg(Dct-Sox10) sets the stage for future investigations into the genetic basis of strain-specific contributions to melanocyte stem cell biology.
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Affiliation(s)
- Melissa L Harris
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
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18
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Abstract
INTRODUCTION Melanocytes produce pigment granules that color both skin and hair. In the hair follicles melanocytes are derived from stem cells (MelSCs) that are present in hair bulges or sub-bulge regions and function as melanocyte reservoirs. Quiescence, maintenance, activation and proliferation of MelSCs are controlled by specific activities in the microenvironment that can influence the differentiation and regeneration of melanocytes. Therefore, understanding MelSCs and their niche may lead to use of MelSCs in new treatments for various pigmentation disorders. AREAS COVERED We describe here pathophysiological mechanisms by which melanocyte defects lead to skin pigmentation disorders such as vitiligo and hair graying. The development, migration and proliferation of melanocytes and factors involved in the survival, maintenance and regeneration of MelSCs are reviewed with regard to the biological roles and potential therapeutic applications in skin pigmentation diseases. EXPERT OPINION MelSC biology and niche factors have been studied mainly in murine experimental models. Human MelSC markers or methods to isolate them are much less well understood. Identification, isolation and culturing of human MelSCs would represent a major step toward new biological therapeutic options for patients with recalcitrant pigmentary disorders or hair graying. By modulating the niche factors for MelSCs, it may one day be possible to control skin pigmentary disorders and prevent or reverse hair graying.
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Affiliation(s)
- Ju Hee Lee
- Massachusetts General Hospital, Harvard Medical School, Department of Dermatology and Cutaneous Biology Research Center , Boston, MA 02129 , USA +1 617 643 5428 ; +1 617 643 6588 ;
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19
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Misery L. [What's new in dermatological research?]. Ann Dermatol Venereol 2013; 139 Suppl 5:S188-93. [PMID: 23522705 DOI: 10.1016/s0151-9638(12)70133-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Dermatological research is more and more productive and its level higher and higher. Choosing the most significant articles is difficult. Mast cell plays a role in the initiation of inflammation and therefore in poorer healing. Keratinocytes derive from stem cells and progenitors, which are independent. They can be activated directly by heat through sensory proteins at their surface. The cutaneous nervous system has an organization similar to that of the most complex sensory organs. In psoriasis, denervation induces a significant plaque regression. The cerebral integration of skin appearance modulates the skin reactivity to histamine. Pruritus is linked to specific receptors in the skin, which give specific projections into the brain and are histamine-dependent or not. Atopic dermatitis may be linked to the nonspecific activation of Th2 immune system, particularly to abnormalities of the skin barrier. Skin bacteria, but not intestinal, modulate the formation of skin immunity. Raf kinases are well known in melanoma and play an important role in physiological conditions: they are not essential to the initial development of the melanocyte lineage but to maintain it. In culture, melanocytes can be dedifferentiated in melanoblasts. Sunburns are consecutive to the activation of TLR3 by UVB. ANRIL gene is involved in the polymorphism of neurofibromatosis 1 and gene RAD51B is linked to the risk of male breast cancer. MCV infection is linked to sites with sialic acid. Aging objectified by telomere shortening is accelerated by stress.
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Affiliation(s)
- L Misery
- Service de Dermatologie, CHU de Brest, 2, avenue Foch, 29200 Brest, France.
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20
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Bonfiglio JJ, Inda C, Senin S, Maccarrone G, Refojo D, Giacomini D, Turck CW, Holsboer F, Arzt E, Silberstein S. B-Raf and CRHR1 internalization mediate biphasic ERK1/2 activation by CRH in hippocampal HT22 Cells. Mol Endocrinol 2013; 27:491-510. [PMID: 23371389 DOI: 10.1210/me.2012-1359] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
CRH is a key regulator of neuroendocrine, autonomic, and behavioral response to stress. CRH-stimulated CRH receptor 1 (CRHR1) activates ERK1/2 depending on intracellular context. In a previous work, we demonstrated that CRH activates ERK1/2 in limbic areas of the mouse brain (hippocampus and basolateral amygdala). ERK1/2 is an essential mediator of hippocampal physiological processes including emotional behavior, synaptic plasticity, learning, and memory. To elucidate the molecular mechanisms by which CRH activates ERK1/2 in hippocampal neurons, we used the mouse hippocampal cell line HT22. We document for the first time that ERK1/2 activation in response to CRH is biphasic, involving a first cAMP- and B-Raf-dependent early phase and a second phase that critically depends on CRHR1 internalization and β-arrestin2. By means of mass-spectrometry-based screening, we identified B-Raf-associated proteins that coimmunoprecipitate with endogenous B-Raf after CRHR1 activation. Using molecular and pharmacological tools, the functional impact of selected B-Raf partners in CRH-dependent ERK1/2 activation was dissected. These results indicate that 14-3-3 proteins, protein kinase A, and Rap1, are essential for early CRH-induced ERK1/2 activation, whereas dynamin and vimentin are required for the CRHR1 internalization-dependent phase. Both phases of ERK1/2 activation depend on calcium influx and are affected by calcium/calmodulin-dependent protein kinase II inactivation. Thus, this report describes the dynamics and biphasic nature of ERK1/2 activation downstream neuronal CRHR1 and identifies several new critical components of the CRHR1 signaling machinery that selectively controls the early and late phases of ERK1/2 activation, thus providing new potential therapeutic targets for stress-related disorders.
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Affiliation(s)
- Juan J Bonfiglio
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA), CONICET, Partner Institute of the Max Planck Society, Godoy Cruz 2390, C1425FQA Buenos Aires, Argentina
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