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Ademi H, Michalak-Micka K, Moehrlen U, Biedermann T, Klar AS. Effects of an Adipose Mesenchymal Stem Cell-Derived Conditioned medium and TGF-β1 on Human Keratinocytes In Vitro. Int J Mol Sci 2023; 24:14726. [PMID: 37834173 PMCID: PMC10572767 DOI: 10.3390/ijms241914726] [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: 08/16/2023] [Revised: 09/06/2023] [Accepted: 09/27/2023] [Indexed: 10/15/2023] Open
Abstract
Human keratinocytes play a crucial role during skin wound healing and in skin replacement therapies. The secretome of adipose-derived stem cells (ASCs) has been shown to secrete pro-healing factors, among which include TGF-β1, which is essential for keratinocyte migration and the re-epithelialization of cutaneous wounds during skin wound healing. The benefits of an ASC conditioned medium (ASC-CM) are primarily orchestrated by trophic factors that mediate autocrine and paracrine effects in keratinocytes. Here, we evaluated the composition and the innate characteristics of the ASC secretome and its biological effects on keratinocyte maturation and wound healing in vitro. In particular, we detected high levels of different growth factors, such as HGF, FGFb, and VEGF, and other factors, such as TIMP1 and 4, IL8, PAI-1, uPA, and IGFBP-3, in the ASC-CM. Further, we investigated, using immunofluorescence and flow cytometry, the distinct effects of a human ASC-CM and/or synthetic TGF-β1 on human keratinocyte proliferation, migration, and cell apoptosis suppression. We demonstrated that the ASC-CM increased keratinocyte proliferation as compared to TGF-β1 treatment. Further, we found that the ASC-CM exerted cell cycle progression in keratinocytes via regulating the phases G1, S, and G2/M. In particular, cells subjected to the ASC-CM demonstrated increased DNA synthesis (S phase) compared to the TGF-β1-treated KCs, which showed a pronounced G0/G1 phase. Furthermore, both the ASC-CM and TGF-β1 conditions resulted in a decreased expression of the late differentiation marker CK10 in human keratinocytes in vitro, whereas both treatments enhanced transglutaminase 3 and loricrin expression. Interestingly, the ASC-CM promoted significantly increased numbers of keratinocytes expressing epidermal basal keratinocyte markers, such DLL1 and Jagged2 Notch ligands, whereas those ligands were significantly decreased in TGF-β1-treated keratinocytes. In conclusion, our findings suggest that the ASC-CM is a potent stimulator of human keratinocyte proliferation in vitro, particularly supporting basal keratinocytes, which are crucial for a successful skin coverage after transplantation. In contrast, TGF-β1 treatment decreased keratinocyte proliferation and specifically increased the expression of differentiation markers in vitro.
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Affiliation(s)
- Hyrije Ademi
- Tissue Biology Research Unit, Department of Surgery, University Children’s Hospital Zurich, 8952 Schlieren, Switzerland
- Children’s Research Center, University Children’s Hospital Zurich, 8032 Zurich, Switzerland
- Faculty of Medicine, University of Zurich, 8032 Zurich, Switzerland
| | - Katarzyna Michalak-Micka
- Tissue Biology Research Unit, Department of Surgery, University Children’s Hospital Zurich, 8952 Schlieren, Switzerland
- Children’s Research Center, University Children’s Hospital Zurich, 8032 Zurich, Switzerland
- Faculty of Medicine, University of Zurich, 8032 Zurich, Switzerland
| | - Ueli Moehrlen
- Tissue Biology Research Unit, Department of Surgery, University Children’s Hospital Zurich, 8952 Schlieren, Switzerland
- Children’s Research Center, University Children’s Hospital Zurich, 8032 Zurich, Switzerland
- Faculty of Medicine, University of Zurich, 8032 Zurich, Switzerland
- Department of Surgery, University Children’s Hospital Zurich, 8032 Zurich, Switzerland
| | - Thomas Biedermann
- Tissue Biology Research Unit, Department of Surgery, University Children’s Hospital Zurich, 8952 Schlieren, Switzerland
- Children’s Research Center, University Children’s Hospital Zurich, 8032 Zurich, Switzerland
- Faculty of Medicine, University of Zurich, 8032 Zurich, Switzerland
| | - Agnes S. Klar
- Tissue Biology Research Unit, Department of Surgery, University Children’s Hospital Zurich, 8952 Schlieren, Switzerland
- Children’s Research Center, University Children’s Hospital Zurich, 8032 Zurich, Switzerland
- Faculty of Medicine, University of Zurich, 8032 Zurich, Switzerland
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2
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Sun L, Yu G, Jiang H, Shi K, Huang D, Bao H, Huang Y, Che L, Chen M. Experimental study on the anti-inflammatory effect of Mongolian medicine Sendeng Decoction on mice with psoriasis. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2022. [DOI: 10.1016/j.medntd.2022.100154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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3
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Savina A, Jaffredo T, Saldmann F, Faulkes CG, Moguelet P, Leroy C, Marmol DD, Codogno P, Foucher L, Zalc A, Viltard M, Friedlander G, Aractingi S, Fontaine RH. Single-cell transcriptomics reveals age-resistant maintenance of cell identities, stem cell compartments and differentiation trajectories in long-lived naked mole-rats skin. Aging (Albany NY) 2022; 14:3728-3756. [PMID: 35507806 PMCID: PMC9134947 DOI: 10.18632/aging.204054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 04/25/2022] [Indexed: 11/25/2022]
Abstract
Naked mole-rats (NMR) are subterranean rodents characterized by an unusual longevity coupled with an unexplained resistance to aging. In the present study, we performed extensive in situ analysis and single-cell RNA-sequencing comparing young and older animals. At variance with other species, NMR exhibited a striking stability of skin compartments and cell types, which remained stable over time without aging-associated changes. Remarkably, the number of stem cells was constant throughout aging. We found three classical cellular states defining a unique keratinocyte differentiation trajectory that were not altered after pseudo-temporal reconstruction. Epidermal gene expression did not change with aging either. Langerhans cell clusters were conserved, and only a higher basal stem cell expression of Igfbp3 was found in aged animals. In accordance, NMR skin healing closure was similar in young and older animals. Altogether, these results indicate that NMR skin is characterized by peculiar genetic and cellular features, different from those previously demonstrated for mice and humans. The remarkable stability of the aging NMR skin transcriptome likely reflects unaltered homeostasis and resilience.
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Affiliation(s)
| | - Thierry Jaffredo
- Institut de Biologie Paris Seine (IBPS), Laboratoire de Biologie du Développement, Sorbonne Université, CNRS, INSERM, Paris, France
| | | | - Chris G Faulkes
- Queen Mary University of London, School of Biological and Chemical Sciences, London, United Kingdom
| | - Philippe Moguelet
- Service d'Anatomie et Cytologie Pathologiques, Hôpital Tenon, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Christine Leroy
- Université Paris Cité, CNRS, INSERM, Institut Necker-Enfants Malades, Paris, France
| | | | - Patrice Codogno
- Université Paris Cité, CNRS, INSERM, Institut Necker-Enfants Malades, Paris, France
| | - Lucy Foucher
- Ecole Nationale Vétérinaire d'Alfort, Centre de Recherche Biomédicale, Maisons-Alfort, France
| | - Antoine Zalc
- Université Paris Cité, CNRS, INSERM, Institut Cochin, Paris, France
| | - Mélanie Viltard
- Fondation pour la Recherche en Physiologie, Brussels, Belgium
| | - Gérard Friedlander
- Université Paris Cité, CNRS, INSERM, Institut Necker-Enfants Malades, Paris, France
| | - Selim Aractingi
- Université Paris Cité, CNRS, INSERM, Institut Cochin, Paris, France.,Service de Dermatologie, Hôpital Cochin, Assistance Publique-Hôpitaux de Paris, France
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4
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Li D, Cheng S, Pei Y, Sommar P, Kärner J, Herter EK, Toma MA, Zhang L, Pham K, Cheung YT, Liu Z, Chen X, Eidsmo L, Deng Q, Xu Landén N. Single-Cell Analysis Reveals Major Histocompatibility Complex II‒Expressing Keratinocytes in Pressure Ulcers with Worse Healing Outcomes. J Invest Dermatol 2021; 142:705-716. [PMID: 34536485 DOI: 10.1016/j.jid.2021.07.176] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 07/13/2021] [Accepted: 07/26/2021] [Indexed: 12/28/2022]
Abstract
Pressure ulcer (PU) is a chronic wound often seen in patients with spinal cord injury and other bed-bound individuals, particularly in the elderly population. Despite its association with high mortality, the pathophysiology of PU remains poorly understood. In this study, we compared single-cell transcriptomic profiles of human epidermal cells from PU wound edges with those from uninjured skin and acute wounds in healthy donors. We identified significant shifts in the cell composition and gene expression patterns in PU. In particular, we found that major histocompatibility complex class II‒expressing keratinocytes were enriched in patients with worse healing outcomes. Furthermore, we showed that the IFN-γ in PU-derived wound fluid could induce major histocompatibility complex II expression in keratinocytes and that these wound fluid‒treated keratinocytes inhibited autologous T-cell activation. In line with this observation, we found that T cells from PUs enriched with major histocompatibility complex II+ keratinocytes produced fewer inflammatory cytokines. Overall, our study provides a high-resolution molecular map of human PU compared with that of acute wounds and intact skin, providing insights into PU pathology and the future development of tailored wound therapy.
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Affiliation(s)
- Dongqing Li
- Dermatology and Venereology Division, Department of Medicine Solna, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Shangli Cheng
- Department of Physiology and Pharmacology, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden; Ming Wai Lau Centre for Reparative Medicine, Karolinska Institute, Stockholm, Sweden
| | - Yu Pei
- Department of Physiology and Pharmacology, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Pehr Sommar
- Department of Reconstructive Plastic Surgery, Karolinska University Hospital, Stockholm, Sweden
| | - Jaanika Kärner
- Division of Rheumatology, Department of Medicine Solna, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Eva K Herter
- Dermatology and Venereology Division, Department of Medicine Solna, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Maria A Toma
- Dermatology and Venereology Division, Department of Medicine Solna, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Letian Zhang
- Dermatology and Venereology Division, Department of Medicine Solna, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Kim Pham
- Dermatology and Venereology Division, Department of Medicine Solna, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Yuen Ting Cheung
- Dermatology and Venereology Division, Department of Medicine Solna, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Zhuang Liu
- Dermatology and Venereology Division, Department of Medicine Solna, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Xingqi Chen
- Department of Immunology, Genetics and Pathology, Faculty of Medicine, Uppsala University, Uppsala, Sweden
| | - Liv Eidsmo
- Division of Rheumatology, Department of Medicine Solna, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden; Leo Foundation Skin Immunology Center, Department of Immunology and Microbiology, Copenhagen University, Copenhagen, Denmark
| | - Qiaolin Deng
- Department of Physiology and Pharmacology, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Ning Xu Landén
- Dermatology and Venereology Division, Department of Medicine Solna, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden; Ming Wai Lau Centre for Reparative Medicine, Karolinska Institute, Stockholm, Sweden.
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Intracellular Insulin-like growth factor binding protein 2 (IGFBP2) contributes to the senescence of keratinocytes in psoriasis by stabilizing cytoplasmic p21. Aging (Albany NY) 2020; 12:6823-6851. [PMID: 32302288 PMCID: PMC7202509 DOI: 10.18632/aging.103045] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 03/09/2020] [Indexed: 12/11/2022]
Abstract
Psoriasis is a chronic Th1/Th17 lymphocytes-mediated inflammatory skin disease, in which epidermal keratinocytes exhibit a peculiar senescent state, resistance to apoptosis and the acquisition of senescence-associated secretory phenotype (SASP). SASP consists of the release of soluble factors, including IGFBPs, that exert extracellular and intracellular functions in IGF-dependent or independent manner.In this report, we investigated the expression and function of IGFBP2 in senescent keratinocytes isolated from the skin of patients with plaque psoriasis. We found that IGFBP2 is aberrantly expressed and released by these cells in vivo, as well as in vitro in keratinocyte cultures undergoing progressive senescence, and it associates with the cyclin-dependent kinase inhibitors p21 and p16 expression. For the first time, we provide evidence for a dual action of IGFBP2 in psoriatic keratinocytes during growth and senescence processes. While extracellular IGFBP2 counter-regulates IGF-induced keratinocyte hyper-proliferation, intracellular IGFBP2 inhibits apoptosis by interacting with p21 and protecting it from ubiquitin-dependent degradation. Indeed, we found that cytoplasmic p21 sustains anti-apoptotic processes, by inhibiting pro-caspase 3 cleavage and JNK phosphorylation in senescent psoriatic keratinocytes. As a consequence, abrogation of p21, as well as that of IGFBP2, found to stabilize cytoplasmic p21 levels, lead to the restoration of apoptosis mechanisms in psoriatic keratinocytes, commonly observed in healthy cells.
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Stuard WL, Titone R, Robertson DM. The IGF/Insulin-IGFBP Axis in Corneal Development, Wound Healing, and Disease. Front Endocrinol (Lausanne) 2020; 11:24. [PMID: 32194500 PMCID: PMC7062709 DOI: 10.3389/fendo.2020.00024] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 01/14/2020] [Indexed: 12/11/2022] Open
Abstract
The insulin-like growth factor (IGF) family plays key roles in growth and development. In the cornea, IGF family members have been implicated in proliferation, differentiation, and migration, critical events that maintain a smooth refracting surface that is essential for vision. The IGF family is composed of multiple ligands, receptors, and ligand binding proteins. Expression of IGF type 1 receptor (IGF-1R), IGF type 2 receptor (IGF-2R), and insulin receptor (INSR) in the cornea has been well characterized, including the presence of the IGF-1R and INSR hybrid (Hybrid-R) in the corneal epithelium. Recent data also indicates that each of these receptors display unique intracellular localization. Thus, in addition to canonical ligand binding at the plasma membrane and the initiation of downstream signaling cascades, IGF-1R, INSR, and Hybrid-R also function to regulate mitochondrial stability and nuclear gene expression. IGF-1 and IGF-2, two of three principal ligands, are polypeptide growth factors that function in all cellular layers of the cornea. Unlike IGF-1 and IGF-2, the hormone insulin plays a unique role in the cornea, different from many other tissues in the body. In the corneal epithelium, insulin is not required for glucose uptake, due to constitutive activation of the glucose transporter, GLUT1. However, insulin is needed for the regulation of metabolism, circadian rhythm, autophagy, proliferation, and migration after wounding. There is conflicting evidence regarding expression of the six IGF-binding proteins (IGFBPs), which function primarily to sequester IGF ligands. Within the cornea, IGFBP-2 and IGFBP-3 have identified roles in tissue homeostasis. While IGFBP-3 regulates growth control and intracellular receptor localization in the corneal epithelium, both IGFBP-2 and IGFBP-3 function in corneal fibroblast differentiation and myofibroblast proliferation, key events in stromal wound healing. IGFBP-2 has also been linked to cellular overgrowth in pterygium. There is a clear role for IGF family members in regulating tissue homeostasis in the cornea. This review summarizes what is known regarding the function of IGF and related proteins in corneal development, during wound healing, and in the pathophysiology of disease. Finally, we highlight key areas of research that are in need of future study.
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Osher E, Macaulay VM. Therapeutic Targeting of the IGF Axis. Cells 2019; 8:E895. [PMID: 31416218 PMCID: PMC6721736 DOI: 10.3390/cells8080895] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 08/04/2019] [Accepted: 08/09/2019] [Indexed: 12/17/2022] Open
Abstract
The insulin like growth factor (IGF) axis plays a fundamental role in normal growth and development, and when deregulated makes an important contribution to disease. Here, we review the functions mediated by ligand-induced IGF axis activation, and discuss the evidence for the involvement of IGF signaling in the pathogenesis of cancer, endocrine disorders including acromegaly, diabetes and thyroid eye disease, skin diseases such as acne and psoriasis, and the frailty that accompanies aging. We discuss the use of IGF axis inhibitors, focusing on the different approaches that have been taken to develop effective and tolerable ways to block this important signaling pathway. We outline the advantages and disadvantages of each approach, and discuss progress in evaluating these agents, including factors that contributed to the failure of many of these novel therapeutics in early phase cancer trials. Finally, we summarize grounds for cautious optimism for ongoing and future studies of IGF blockade in cancer and non-malignant disorders including thyroid eye disease and aging.
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Affiliation(s)
- Eliot Osher
- Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
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Póvoa G, Diniz LM. Growth hormone system: skin interactions. An Bras Dermatol 2012; 86:1159-65. [PMID: 22281905 DOI: 10.1590/s0365-05962011000600015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Accepted: 02/09/2011] [Indexed: 11/21/2022] Open
Abstract
This paper describes the growth hormone system, emphasizing its possible effects on epidermal cells, dermal structures and wound healing. A review of the literature was conducted on studies concerning the growth hormone molecule, its receptor and carrier proteins and the other proteins involved in the mechanisms of its manifestation in dermal tissue.
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Affiliation(s)
- Guilherme Póvoa
- Department of Internal Medicine, Health Sciences Center, Federal University of Espírito Santo, Vitória, ES, Brazil.
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Sugiyama-Nakagiri Y, Naoe A, Ohuchi A, Kitahara T. Serum levels of IGF-1 are related to human skin characteristics including the conspicuousness of facial pores. Int J Cosmet Sci 2011; 33:144-9. [DOI: 10.1111/j.1468-2494.2010.00602.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Involvement of IGF-1/IGFBP-3 signaling on the conspicuousness of facial pores. Arch Dermatol Res 2010; 302:661-7. [PMID: 20567839 DOI: 10.1007/s00403-010-1062-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2010] [Revised: 06/08/2010] [Accepted: 06/10/2010] [Indexed: 01/28/2023]
Abstract
Conspicuous facial pores are one type of serious esthetic defects for many women. We previously reported that the severity of impairment of skin architecture around facial pores correlates well with the appearance of facial pores in several ethnic groups. In our last report, we showed that serum levels of insulin-like growth factor-1 (IGF-1) correlate well with facial pore size and with the severity of impairment of epidermal architecture around facial pores. However, our results could not fully explain the implication between facial pores and IGF signaling. In this study, we conducted a histological analysis of facial skin to determine whether potential changes in IGF-1 availability occur in the skin with or without conspicuous pores. Immunohistochemical observations showed that expression of insulin-like growth factor binding protein-3 (IGFBP-3) is limited to the suprapapillary epidermis around facial pores and to basal cells of rete pegs without tips in epidermis with conspicuous pores. In contrast, in basal cells of skin without conspicuous pores, IGFBP-3 expression is very low. Ki-67 and IGF-1 receptor-positive cells are abundant in basal cells in the tips of the rete pegs in skin with typical epidermal architecture around facial pores. No obvious differences were observed in the expression of filaggrin, involucrin, K1, K6 or K17 in skin with or without conspicuous pores. However, increased expression of K16 was observed in skin with conspicuous pores suggesting hyperproliferation. These results suggest that the IGF-1/IGFBP-3 signaling pathway is involved in the formation of conspicuous facial pores due to the epidermal architecture around facial pores.
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Özden MG, İlter N, Suer ÖE, Solaktekin N, Gürer MA. Increased insulin-like growth factor binding protein-3 expression level in psoriatic tissue before and after systemic treatment with cyclosporine A and methotrexate. Int J Dermatol 2008; 47:1177-83. [DOI: 10.1111/j.1365-4632.2008.03810.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Damasiewicz-Bodzek A, Kos-Kudła B, Suwała-Jurczyk B. The effect of various methods of psoriasis treatment on somatotrophin axis hormones in serum. J Clin Pharm Ther 2006; 31:343-9. [PMID: 16882103 DOI: 10.1111/j.1365-2710.2006.00747.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVE To investigate the effect of pharmacotherapy and phototherapy on the concentration of hormones of the somatotrophin axis [growth hormone (GH), insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3)] in the serum of patients with psoriasis in exacerbation and remission. METHODS GH and IGFBP-3 in serum were determined by immunoradiometric assay (IRMA), and IGF-I concentrations - by radioimmunological assay (RIA). The dermatological state was assessed by the psoriasis area and severity index (PASI). RESULTS There was no significant difference in the GH concentrations in patients both in exacerbation and remission, irrespective of therapy applied. However, in the group treated by phototherapy a significant increase in IGFBP-3 secretion was observed, whereas in the group treated with cyclosporin A - a significant increase in IGF-I secretion was observed in remission. CONCLUSION Different methods of treatment have different effects on the secretion of somatotrophin axis hormones, but generally the hormone concentrations do not return to the values observed in healthy people. The therapeutic actions of the drugs concerned are not fully known and require further investigations.
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Mark EB, Jonsson M, Asp J, Wennberg AM, Mölne L, Lindahl A. Expression of genes involved in the regulation of p16 in psoriatic involved skin. Arch Dermatol Res 2006; 297:459-67. [PMID: 16552541 DOI: 10.1007/s00403-006-0649-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2005] [Revised: 10/12/2005] [Accepted: 02/13/2006] [Indexed: 01/03/2023]
Abstract
It has been suggested that the up-regulation of the tumour suppressor p16 gene and induction of senescence protect the phenotype of psoriatic involved skin from malignant transformation. On the other hand, Id1, which is inversely correlated with p16 has been shown to be up-regulated in psoriatic involved skin. To test the hypothesis that there may be an altered regulation of p16 in psoriatic involved skin, we have measured genes involved in the Igf-1 receptor signalling through the Ras/MAPK cascade. Igf-1R, IGFBP3, hRas, Ets2, JunB, Egr-1, Id1, MIDA1 and p16 gene expressions were measured using quantitative real-time PCR in total RNA isolated from punch biopsies from psoriatic involved (n = 9) and uninvolved skin (n = 9) and from cutaneous squamous cell cancer (SCC) involved (n = 8) and uninvolved skin (n = 8). The IGFBP3, hRas, JunB, Egr-1, Id1 and MIDA1 genes were up-regulated in psoriatic involved skin compared with uninvolved skin. The p16, JunB and MIDA1 genes were up-regulated in SCC involved skin compared with uninvolved skin. Our results indicate that there may be a balance between the proliferation and induction of senescence in psoriasis. This balance may vary and the psoriatic involved skin represented in this study appears to be in a proliferative state rather than senescence. Furthermore, we suggest that the noted up-regulation of JunB, which has been shown to up-regulate p16, in combination with the previously reported elevation of p16 expression in psoriatic involved skin, may indicate activation of a pathway by which JunB may protect the psoriatic plaque by inducing p16 in an event of malignant stress.
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Affiliation(s)
- Elisabeth Björntorp Mark
- Department of Dermatology, Sahlgrenska University Hospital, Göteborg University, 413 45, Göteborg, Sweden.
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Edmondson SR, Thumiger SP, Kaur P, Loh B, Koelmeyer R, Li A, Silha JV, Murphy LJ, Wraight CJ, Werther GA. Insulin-like growth factor binding protein-3 (IGFBP-3) localizes to and modulates proliferative epidermal keratinocytes in vivo. Br J Dermatol 2005; 152:225-30. [PMID: 15727632 DOI: 10.1111/j.1365-2133.2004.06350.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND The colocalization of insulin-like growth factor binding protein-3 (IGFBP-3) and IGF-I receptor (IGF-IR) in the basal/germinative layer of the epidermis suggests a key role in modulating epidermal homeostasis. OBJECTIVES We aimed to clarify both the specific cellular localization and the effect of excess epidermal IGFBP-3 on keratinocyte proliferation. METHODS (i) Total RNA was isolated from fluorescence-activated cell sorted basal human keratinocyte subtypes [keratinocyte stem cells, transit amplifying keratinocytes (TA), postmitotic differentiating keratinocytes (PMD)], and real-time polymerase chain reaction analysis was used to determine the abundance of IGFBP-3 and IGF-IR mRNAs. (ii) An IGFBP-3 transgenic mouse model was then used to assess the effect of excess epidermal IGFBP-3 on keratinocyte proliferation. Excess epidermal IGFBP-3 mRNA and protein was determined by in situ hybridization and immunohistochemistry, respectively. RESULTS (i) The highest levels of IGFBP-3 mRNA were detected in TA keratinocytes, in contrast to IGF-IR mRNA levels which were highest in PMD keratinocytes. (ii) Elevated human IGFBP-3 mRNA and protein was confirmed in the epidermis of skin derived from transgenic mice. Excess IGFBP-3 reduced the relative percentage of proliferative keratinocytes (Ki67 positive) irrespective of skin location (belly, back and tail). Thus, in the epidermis, IGFBP-3 mRNA is highly expressed by proliferative keratinocytes (TA) and overexpression of IGFBP-3 inhibits keratinocyte proliferation. CONCLUSIONS We conclude that in vivo IGFBP-3 ensures epidermal homeostasis via downregulation of keratinocyte proliferation, and thus modulates the early stages of keratinocyte differentiation.
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Affiliation(s)
- S R Edmondson
- Epithelial Stem Cell Biology Laboratory, Peter MacCallum Cancer Institute, East Melbourne, 3002 Victoria, Australia
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15
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Thumiger SP, Adams TE, Werther GA, Wraight CJ, Edmondson SR. UV induced responses of the human epidermal IGF system: impaired anti-apoptotic effects of IGF-I in HaCaT keratinocytes. Growth Factors 2005; 23:151-9. [PMID: 16019437 DOI: 10.1080/08977190500153680] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The insulin-like growth factor receptor (IGF-IR) is critical in epidermal development and IGF binding protein-3 (IGFBP-3), a modulator of cellular activity with or without IGF-dependence, co-localises with epidermal IGF-IRs. We have investigated whether the greater UV susceptibility of a human keratinocyte cell line (HaCaT) in comparison to normal human keratinocytes (NHKs) may involve differences in the IGF system. At 24 h after UV (960 mJ/cm(2) UVB), in comparison to NHKs, HaCaT keratinocytes exhibited significantly higher levels of apoptosis, refractoriness to IGF-I treatment and reduced IGF-IR phosphorylation. Secreted, intact IGFBP-3 (38-42 kDa) and IGFBP-3 mRNA abundance were reduced in HaCaT keratinocytes, but not consistently altered in NHKs. Immunoreactive IGFBP-3 fragments (16-11 kDa) were detected in both UV-exposed cultures. These data suggest that an altered IGF system contributes to HaCaT keratinocyte UV susceptibility and that following UV insult the IGF system may enhance keratinocyte viability and contribute to a return to epidermal homeostasis.
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Affiliation(s)
- Susan P Thumiger
- Centre for Hormone Research, Murdoch Childrens Research Institute, Royal Children's Hospital, University of Melbourne, Flemington Road, Parkville, Victoria, Australia
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16
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Abstract
Antisense oligonucleotides are emerging as an exciting therapeutic strategy for treating skin diseases such as psoriasis. Potential antisense targets are proteins upregulated in psoriatic skin, in particular those associated with inflammation (intercellular adhesion molecule [ICAM]-1, IL-2 and -8), proliferation (insulin-like growth factor type I receptor [IGF-IR], epidermal growth factor) and hyperangiogenesis (vascular endothelial growth factor [VEGF]). Whereas topical application and subsequent penetration of large oligonucleotides into normal skin is problematic, the impaired barrier function of psoriatic lesions permits the uptake of antisense drugs. Studies to date indicate that topically applied antisense molecules can be delivered to target cells in the epidermis and dermis of psoriatic skin. Antisense-mediated suppression of target mRNA and protein has been demonstrated in models of human skin grafted to immunosuppressed mice and in hairless mouse models of skin inflammation. In a xenograft model of human psoriasis, treatment with repeated intradermal injections of IGF-IR antisense caused a normalisation of the epidermal hyperproliferation. This class of drug, therefore, holds much potential for the successful treatment of psoriasis in the clinical setting.
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Affiliation(s)
- P J White
- Department of Pharmaceutical Biology and Pharmacology, Victorian College of Pharmacy, Monash University, Parkville 3052, Australia
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17
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Wang H, Shen SS, Wang H, Diwan AH, Zhang W, Fuller GN, Prieto VG. Expression of insulin-like growth factor-binding protein 2 in melanocytic lesions. J Cutan Pathol 2004; 30:599-605. [PMID: 14744083 DOI: 10.1034/j.1600-0560.2003.00120.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Insulin-like growth factor-1 (IGF-1) is one of the most critical proteins required for the survival, migration, and growth of melanoma cells. IGF-binding protein 2 (IGFBP2), which binds and regulates the function of IGF-1, is upregulated in a dose-dependent manner in melanoma cells treated with IGF-1, suggesting a possible role of IGFBP2 in the pathogenesis of melanoma. METHODS Tissue microarrays were constructed using formalin-fixed, paraffin-embedded archival tissue blocks from 94 melanocytic lesions: 20 benign nevi, 20 dysplastic nevi, 23 primary melanomas, and 31 metastatic melanomas. IGFBP2 expression was evaluated immunohistochemically using a polyclonal antibody against the C-terminus of IGFBP2. The number of cells and labeling intensity were assessed semiquantitatively. RESULTS Positive IGFBP2 labeling was observed in 5.0% of benign nevi, which was significantly lower than in dysplastic nevi (35.0%), primary melanomas (52.2%), or metastatic melanomas (54.8%) (p < 0.05). Among the IGFBP2-positive cases, moderate-to-strong immunostaining was observed in 64.7% of metastatic melanomas and 33.3% of primary melanomas. But none of the dysplastic nevi had moderate-to-strong immunostaining (p < 0.05). CONCLUSIONS Our study shows that IGFBP2 expression increases from benign and dysplastic nevi to primary and metastatic melanomas and suggests that it may play a role in melanoma progression.
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Affiliation(s)
- Huamin Wang
- Department of Pathology and Laboratory Medicine, The University of Texas Medical School at Houston, USA
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18
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Edmondson SR, Thumiger SP, Werther GA, Wraight CJ. Epidermal homeostasis: the role of the growth hormone and insulin-like growth factor systems. Endocr Rev 2003; 24:737-64. [PMID: 14671001 DOI: 10.1210/er.2002-0021] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
GH and IGF-I and -II were first identified by their endocrine activity. Specifically, IGF-I was found to mediate the linear growth-promoting actions of GH. It is now evident that these two growth factor systems also exert widespread activity throughout the body and that their actions are not always interconnected. The literature highlights the importance of the GH and IGF systems in normal skin homeostasis, including dermal/epidermal cross-talk. GH activity, sometimes mediated via IGF-I, is primarily evident in the dermis, particularly affecting collagen synthesis. In contrast, IGF action is an important feature of the dermal and epidermal compartments, predominantly enhancing cell proliferation, survival, and migration. The locally expressed IGF binding proteins play significant and complex roles, primarily via modulation of IGF actions. Disturbances in GH and IGF signaling pathways are implicated in the pathophysiology of several skin perturbations, particularly those exhibiting epidermal hyperplasia (e.g., psoriasis, carcinomas). Additionally, many studies emphasize the potential use of both growth factors in the treatment of skin wounds; for example, burn patients. This overview concerns the role and mechanisms of action of the GH and IGF systems in skin and maintenance of epidermal integrity in both health and disease.
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Affiliation(s)
- Stephanie R Edmondson
- Centre for Hormone Research, Murdoch Children's Research Institute, Royal Children's Hospital, University of Melbourne, Parkville, Victoria, Australia 3052.
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19
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Sadowski T, Dietrich S, Koschinsky F, Sedlacek R. Matrix metalloproteinase 19 regulates insulin-like growth factor-mediated proliferation, migration, and adhesion in human keratinocytes through proteolysis of insulin-like growth factor binding protein-3. Mol Biol Cell 2003; 14:4569-80. [PMID: 12937269 PMCID: PMC266773 DOI: 10.1091/mbc.e03-01-0009] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Unlike most other matrix metalloproteinases (MMPs) MMP-19 is expressed in undifferentiated basal keratinocytes of healthy human skin. The human keratinocyte cell line HaCaT, which like basal keratinocytes constitutively expresses MMP-19, down-regulated the expression of MMP-19 at high calcium concentrations. Calcium-regulation occurred through E-cadherin mediated cell-cell contacts because neutralizing anti-E-cadherin antibodies restored MMP-19 expression in high calcium. Overexpression of MMP-19 in HaCaT cells (HaCaT-WT) increased cellular proliferation, as well as migration and adhesion on type I collagen. This was due to proteolysis of the insulin-like growth factor (IGF) binding protein-3 by MMP-19, which augmented signaling through the IGF-I receptor, as evidenced by its increased autophosphorylation. Conversely, these effects were not observed in cells transfected with MMP-2 or a catalytically inactive MMP-19 mutant. As further proof that increased IGF-signaling promoted adhesion and migration in HaCaT-WT cells, we reproduced these effects by treating parental HaCaT with IGF-I. We observed dephosphorylation of the focal adhesion kinase in HaCaT-WT as well as IGF-I-treated HaCaT cells, suggesting that inactivating focal adhesion kinase is a mechanism by which IGF-I enhances adhesion. Furthermore, IGF-I-triggered motility on type I collagen was mediated by MMP activity, which, however, was distinct from MMP-19. Considering the coexpression of IGFBP-3 and MMP-19 in the skin, we conclude that MMP-19 is a likely candidate to be the major IGFBP-3 degrading MMP in the quiescent epidermis. This activity might have widespread consequences for the behavior of epidermal keratinocytes.
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Affiliation(s)
- Thorsten Sadowski
- Institute of Biochemistry, Christian-Albrechts-University of Kiel, D-24118 Kiel, Germany
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20
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Fogarty RD, McKean SC, White PJ, Atley LM, Werther GA, Wraight CJ. Sequence dependence of C5-propynyl-dU,dC-phosphorothioate oligonucleotide inhibition of the human IGF-I receptor: mRNA, protein, and cell growth. ANTISENSE & NUCLEIC ACID DRUG DEVELOPMENT 2002; 12:369-77. [PMID: 12568311 DOI: 10.1089/108729002321082447] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Human keratinocytes are highly responsive to mitogenic and antiapoptotic signaling by the insulin-like growth factor-I receptor (IGF-IR). IGF-IR hyperstimulation is a feature of hyperplastic skin conditions, making the IGF-IR an appealing target for antisense therapeutic intervention. In this study, we used a C5-propynyl-dU,dC-phosphorothioate oligo-2'-deoxyribonucleotide antisense 15-mer to the human IGF-IR mRNA, along with liposome transfection, to inhibit IGF-IR activity in a human keratinocyte cell line and demonstrated potent inhibition of cell growth despite the presence of serum. To investigate the sequence specificity of these effects and to establish the concentration range over which a purely antisense effect could be demonstrated, we introduced 1, 2, 4, 8, and 15 base mismatches into the oligonucleotide and analyzed changes in inhibitory efficacy. In the 10-30 nM concentration range, the introduction of 1 and 2 mismatches into the middle of the 15-mer only modestly affected inhibitory efficacy, whereas >4 mismatches profoundly reduced mRNA, protein, and growth-inhibitory effects. From these results, we conclude that (1) sequence-specific antisense inhibition of IGF-IR activity in keratinocytes is achievable, (2) potent anti-IGF-IR antisense inhibition can be achieved in vitro at concentrations as low as 10 nM, and (3) a sequence-dependent mechanism is likely to underpin the observed in vivo therapeutic effects (Wraight et al. Nat. Biotechnol. 2000;18:521) of these antisense oligonucleotides (AS-ODN) in cutaneous hyperplastic disorders, such as psoriasis.
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Affiliation(s)
- Rhys D Fogarty
- Centre for Hormone Research, Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria 3052, Australia
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21
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Abstract
Antisense oligonucleotides have been the subject of intense interest as research tools to elucidate the functions of gene products and as therapeutic agents. Initially, their mode of action was poorly understood and the biological effects of oligonucleotides were often misinterpreted. However, research into these gene-based inhibitors of cellular action recently has succeeded in realising their exciting potential, particularly as novel therapeutic agents. An emerging application of this technology is in cutaneous therapy. The demand for more effective dermatological drugs will ensure further development of antisense strategies in skin, with key issues being drug delivery, therapeutic target selection, and clinical applicability.
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Affiliation(s)
- C J Wraight
- Centre for Hormone Research, Murdoch Childrens Research Institute, Flemington Road, Parkville, Victoria 3052, Australia.
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22
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Edmondson SR, Werther GA, Wraight CJ. Calcium regulates the expression of insulin-like growth factor binding protein-3 by the human keratinocyte cell line HaCaT. J Invest Dermatol 2001; 116:491-7. [PMID: 11286613 DOI: 10.1046/j.0022-202x.2001.temp.doc.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The insulin-like growth factor (IGF) system is essential for epidermal homeostasis. Insulin-like growth factor binding protein 3 (IGFBP-3), a modulator of IGF action that also exhibits IGF-independent activity, is localized to selected keratinocytes in the basal epidermal layer and may thus contribute to keratinocyte differentiation. We have utilized the human keratinocyte cell line, HaCaT, to examine the effect of calcium on the regulation of components of the IGF system. Western ligand and northern blot analyses revealed secreted IGFBP-3 and IGFBP-3 mRNA were reduced by an elevation in calcium levels in the culture medium. At 1.0 and 1.2 mM CaCl2 culture conditions IGFBP-3 abundance was reduced to 36% +/- 1.6% and 26% +/- 7.1%, respectively, of that from cells grown at 0.03 mM CaCl2. IGFBP-3 mRNA levels in 0.7 mM and 1.2 mM CaCl2 were reduced to 46% +/- 17.4% and 24% +/- 4.6%, respectively, compared with IGFBP-3 mRNA levels at 0.03 mM CaCl2. The observed reduction of IGFBP-3 was not associated with IGFBP-3 proteolysis. In contrast IGF-I receptor protein and mRNA levels remained unchanged. The IGF-I stimulated proliferative response of HaCaT keratinocytes showed that under low (0.03 mM) and high (1.2 mM) CaCl2 conditions IGF-I at 100 and 1000 ng per ml similarly increased cell number 2.4- and 2.7-fold, respectively, with similar dose-response curves. HaCaT keratinocytes grown under medium (0.7 mM) and high (1.2 mM), but not low (0.03 mM), CaCl2 conditions for 21 d revealed an induction of profilaggrin mRNA, a marker of keratinocyte differentiation. These studies indicate that the exposure of HaCaT keratinocytes to elevated calcium levels is associated with a decline in IGFBP-3 but not IGF-I receptor levels. These findings suggest a potential mechanism for the distribution of IGFBP-3 in the epidermis, which may be involved in the process of keratinocyte differentiation.
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Affiliation(s)
- S R Edmondson
- Center for Hormone Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia.
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23
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Wraight CJ, White PJ, McKean SC, Fogarty RD, Venables DJ, Liepe IJ, Edmondson SR, Werther GA. Reversal of epidermal hyperproliferation in psoriasis by insulin-like growth factor I receptor antisense oligonucleotides. Nat Biotechnol 2000; 18:521-6. [PMID: 10802619 DOI: 10.1038/75382] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Epidermal hyperplasia is a key feature of the common skin disorder psoriasis. Stimulation of epidermal keratinocytes by insulin-like growth factor I (IGF-I) is essential for cell division, and increased sensitivity to IGF-I may occur in psoriasis. We hypothesized that inhibition of IGF-I receptor expression in the psoriasis lesion would reverse psoriatic epidermal hyperplasia by slowing the rate of keratinocyte cell division. Here we report the use of C5-propynyl-dU,dC-phosphorothioate antisense oligonucleotides to inhibit IGF-I receptor expression in keratinocytes. We identified several inhibitory antisense oligonucleotides and demonstrated IGF-I receptor inhibition in vitro through an mRNA targeting mechanism. Repeated injection of these oligonucleotides into human psoriasis lesions, grafted onto nude mice, caused a dramatic normalization of the hyperplastic epidermis. The findings indicate that IGF-I receptor stimulation is a rate-limiting step in psoriatic epidermal hyperplasia and that IGF-I receptor targeting by cutaneous administration of antisense oligonucleotides forms the basis of a potential new psoriasis therapy.
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Affiliation(s)
- C J Wraight
- Centre for Hormone Research, Royal Children's Hospital, Parkville, Victoria 3052, Australia.
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24
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Edmondson SR, Russo VC, McFarlane AC, Wraight CJ, Werther GA. Interactions between growth hormone, insulin-like growth factor I, and basic fibroblast growth factor in melanocyte growth. J Clin Endocrinol Metab 1999; 84:1638-44. [PMID: 10323393 DOI: 10.1210/jcem.84.5.5692] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Melanocytes, highly differentiated neural crest-derived cells, are located in the basal layer of the epidermis, where they play a role in protecting against UV damage in the skin. Previous studies suggest that both growth hormone (GH) and the insulin-like growth factor I (GH/IGF-I) system may be important for melanocyte growth and function. We have therefore characterized the role of the GH/IGF system in melanocyte growth in vitro and its interaction with the local growth factor basic fibroblast growth factor (bFGF). Analysis of the effects of GH, IGF-I, and bFGF and combinations of these growth factors on melanocyte growth in vitro revealed that 1) GH stimulates the growth of melanocytes when combined with IGF-I, des(1-3)IGF-I [an analog of IGF-I that has a reduced binding affinity for IGF-binding proteins (IGFBPs)], or bFGF, either separately or in combination; 2) in contrast to the lack of effect of GH or bFGF alone, both IGF-I and des(1-3)IGF-I enhance melanocyte growth in a dose-dependent manner; and 3) IGF-I is more efficacious in eliciting a growth response at low concentrations compared to des(1-3)IGF-I. Using Western ligand blotting, affinity cross-linking, immunoprecipitation, RIA, and Northern analysis, we show that cultured human melanocytes synthesize and secrete minimal amounts of IGFBP. IGFBP-4 is the major IGFBP produced by these cells when cultured in complete growth medium or in the presence of either IGF-I or des(1-3)IGF-I alone. In conclusion, these studies provide support for a role for both GH and IGF-I in the growth of human melanocytes in vitro, involving synergy with bFGF. Low levels of melanocyte-derived IGFBP-4 may play a role in enhancing the modulation of IGF action.
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Affiliation(s)
- S R Edmondson
- Centre for Hormone Research, Royal Children's Hospital, Parkville, Victoria, Australia.
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25
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Edmondson SR, Murashita MM, Russo VC, Wraight CJ, Werther GA. Expression of insulin-like growth factor binding protein-3 (IGFBP-3) in human keratinocytes is regulated by EGF and TGFbeta1. J Cell Physiol 1999; 179:201-7. [PMID: 10199559 DOI: 10.1002/(sici)1097-4652(199905)179:2<201::aid-jcp10>3.0.co;2-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Insulin-like growth factor-I (IGF-I) is essential for normal epidermal homeostasis; however, the role of IGF binding proteins (IGFBPs), regulators of IGF action, remains unclear. Here we examine the regulation of human keratinocyte-produced IGFBPs by epidermal growth factor (EGF), transforming growth factor beta 1 (TGFbeta1), and IGF-I, growth factors known to be active in skin. In the absence of added growth factors, IGFBP-3 was the major binding protein secreted into the medium by primary keratinocytes. Addition of EGF or TGFbeta1 to keratinocyte cultures resulted in a significant decrease in IGFBP-3 abundance in conditioned medium when compared with control, untreated cells. Specifically, EGF (50 ng/ml) and TGFbeta1 (50 ng/ml) reduced IGFBP-3 abundance to 15+/-6% and 22+/-9%, respectively. Using Northern blot analysis, we found EGF and TGFbeta1 (50 ng/ml) to reduce IGFBP-3 mRNA levels in keratinocytes to 51+/-12% and 50+/-38%, respectively, when compared with control, untreated cells. Treatment with IGF-I or its analogue des(1-3)IGF-I did not lead to any consistent change in IGFBP-3 abundance. However, both IGF-I and des(1-3)IGF-I at 100 ng/ml led to a modest increase in IGFBP-3 mRNA levels in keratinocytes, suggesting posttranscriptional regulation of IGFBP-3 abundance. We propose that local modulation of IGFBP-3 abundance may represent another level of regulation of growth factor action in the epidermis, where EGF and TGFbeta1 and possibly other local growth factors specifically regulate the availability of IGF-I to its keratinocyte receptors.
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Affiliation(s)
- S R Edmondson
- Centre for Hormone Research, Royal Children's Hospital, Parkville, Victoria, Australia
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26
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Wraight CJ, Liepe IJ, White PJ, Hibbs AR, Werther GA. Intranuclear localization of insulin-like growth factor binding protein-3 (IGFBP-3) during cell division in human keratinocytes. J Invest Dermatol 1998; 111:239-42. [PMID: 9699724 DOI: 10.1046/j.1523-1747.1998.00258.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Insulin-like growth factor-I (IGF-I) stimulation of basal keratinocytes is an essential component of normal epidermal homeostasis. In addition to the IGF receptor, basal keratinocytes synthesize insulin-like growth factor binding protein-3 (IGFBP-3). The HaCaT keratinocyte cell line, which has many characteristics of basal keratinocytes, synthesizes IGFBP-3 that in vitro reduces its IGF-I responsiveness. IGFBP-3 has attracted interest as a potential growth arrest protein, both via its ability to modulate IGF-I responsiveness, and more controversially via IGF-I-independent mechanisms. Intracellular modes of action have been proposed, and a nuclear localization consensus sequence has previously been identified within IGFBP-3. Using immunocytochemistry with a biotinylated antibody specific for IGFBP-3, we investigated the intracellular localization of IGFBP-3 in subconfluent monolayer cultures of HaCaT cells. Diffuse cellular staining was visible, potentially corresponding to cell surface and nascent cytoplasmic IGFBP-3. Of particular interest however, was the localization of staining over the nuclei of a large proportion of cells that were undergoing cell division. Antibody staining was specific for IGFBP-3 because addition of recombinant human IGFBP-3 to the antibody prior to incubation with the cells inhibited these staining patterns. Optical sections obtained using a confocal laser scanning microscope showed that in keratinocytes undergoing cell division, IGFBP-3 was localized inside the nucleus. These results show that intracellular IGFBP-3 localization is altered during the cell cycle and suggest a possible nuclear role for IGFBP-3 during cell division.
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Affiliation(s)
- C J Wraight
- Center for Hormone Research, Royal Children's Hospital, Parkville, Victoria, Australia
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