Epidermal stem cells and skin tissue engineering in hair follicle regeneration

The reconstitution of a fully organized and functional hair follicle from dissociated cells propagated under defined tissue culture conditions is a challenge still pending in tissue engineering. The loss of hair follicles caused by injuries or pathologies such as alopecias not only affects the patients´ psychological well-being, but also endangers certain inherent functions of the skin. It is then of great interest to find different strategies aiming to regenerate or neogenerate the hair follicle under conditions proper of an adult individual. Based upon current knowledge of the epithelial and dermal cells involved in embryonic hair generation and adult hair cycling, and of the epithelial-mesenchymal interactions among them, many researchers have tried to obtain mature hair follicles using different strategies and approaches depending on the causes of hair loss. This review summarizes current advances in the different experimental strategies to regenerate or neogenerate hair follicles, with emphasis on those involving neogenesis of hair follicles in adults from isolated cells and tissue engineering. Most of these experiments were performed using rodent cells, particularly from embryonic or newborn origin. However, no successful strategy to generate human hair follicles from adult cells has yet been reported. This review identifies several issues that should be considered to achieve this objective. Perhaps the most important challenge is to provide the cells with three-dimensional culture conditions mimicking the structure of living tissue. Improving culture conditions that allow the expansion of specific cells without losing their inductive properties, as well as methods of selecting populations of epithelial stem cells should give us the necessary tools to overcome the difficulties that constrain human hair follicle neogenesis. An analysis of patents trends shows that the number of patent applications aiming to hair follicle regeneration and neogenesis has been growing during the last decade, and this field is attractive not only to academic researchers but also to the companies that own almost half of the patents in this field.Fil: Balaña, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencias y Tecnología "Dr. Cesar Milstein"; ArgentinaFil: Charreau, Hernán Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina. Clarke, Modet & C°. Technology Intelligence Unit; ArgentinaFil: Leiros, Gustavo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencias y Tecnología "Dr. Cesar Milstein"; Argentin

Androgens and androgen receptor action in skin and hair follicles

Beyond sexual functions, androgens exert their action in skin physiology andpathophysiology. Skin cells are able to synthesize most of active androgens from gonadal or adrenal precursors and the enzymes involved in skin steroidogenesis are implicated both in normal or pathological processes. Even when the role of androgens and androgen receptor (AR) in skin pathologies has been studied for decades, their molecular mechanisms in skin disorders remain largely unknown. Here, we go over recent studies of androgens and AR roles in several skin-related disorders, focusing in the current understanding of its molecular mechanisms in androgenetic alopecia (AGA). We review on the molecular pathophysiology of type 2 5α-reductase, AR coactivators, the paracrinefactors deregulated in dermal papilla (such as TGF-β, IGF 1, WNTs and DKK-1) and the crosstalk between AR and Wnt signaling in order to shed some light on new promising treatments.Fil: Ceruti, Julieta María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología "Dr. César Milstein". Fundación Pablo Cassará. Instituto de Ciencia y Tecnología "Dr. César Milstein"; ArgentinaFil: Leiros, Gustavo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología "Dr. César Milstein". Fundación Pablo Cassará. Instituto de Ciencia y Tecnología "Dr. César Milstein"; ArgentinaFil: Balaña, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología "Dr. César Milstein". Fundación Pablo Cassará. Instituto de Ciencia y Tecnología "Dr. César Milstein"; Argentin

Androgens downregulate BMP2 impairing the inductive role of dermal papilla cells on hair follicle stem cells differentiation

Hair follicle cyclical regeneration is regulated by epithelial-mesenchymal interactions. During androgenetic alopecia (AGA), hair follicle stem cells (HFSC) differentiation is impaired by deregulation of dermal papilla cells (DPC) secreted factors. We analyzed androgen influence on BMPs expression in DPC and their effect on HFSC differentiation to hair lineage. Androgens downregulated BMP2 and BMP4 in DPC spheroids. Addition of BMP2 restored alkaline phosphatase activity, marker of hair-inductivity in DPC, and DPC-induced HFSC differentiation, both inhibited by androgens. Concomitantly, in differentiating HFSC, an upregulation of BMPRIa and BMPRII receptors and nuclear β-catenin accumulation, indicative of Wnt/β-catenin pathway activation, were detected. Our results present BMP2 as an androgen-downregulated paracrine factor that contributes to DPC inductivity and favors DPC-induced HFSC differentiation to hair lineage, possibly through a crosstalk with Wnt/β-catenin pathway. A comprehensive understanding of androgen-deregulated DPC factors and their effects on differentiating HFSC would help to improve treatments for AGA.Fil: Ceruti, Julieta María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología "Dr. César Milstein". Fundación Pablo Cassará. Instituto de Ciencia y Tecnología "Dr. César Milstein"; ArgentinaFil: Oppenheimer, Florencia Maia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología "Dr. César Milstein". Fundación Pablo Cassará. Instituto de Ciencia y Tecnología "Dr. César Milstein"; ArgentinaFil: Leiros, Gustavo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología "Dr. César Milstein". Fundación Pablo Cassará. Instituto de Ciencia y Tecnología "Dr. César Milstein"; ArgentinaFil: Balaña, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología "Dr. César Milstein". Fundación Pablo Cassará. Instituto de Ciencia y Tecnología "Dr. César Milstein"; Argentin

Dermal Papilla Cells improve the wound healing process and generate hair bud-like structures in grafted skin substitutes using Hair Follicle Stem Cells

Tissue-engineered skin represents a useful strategy for the treatment of deep skin injuries and may contribute to the understanding of skin regeneration. The growth of hair follicles in vitro or after grafting remains a major challenge. The dermal-epidermal composites are skin substitutes comprised of dermal fibroblasts (DF) embedded in a matrix overlaid with keratinocytes. Hair Follicle Stem Cells (HFSC) contribute to hair follicle regeneration and wound repair. Dermal papilla cells (DPC) signaling orchestrates hair follicle morphogenesis and regeneration. The use of DPC as dermal component in a permanent composite skin with human HFSC was evaluated by studying tissue-engineered skin architecture, stem cell persistence and hair regeneration as well as the graft-take in nude mice. A porcine acellular dermal matrix (ADM) was seeded with HFSC alone and with human DPC or DF. Histological and immunohistochemical analyses of in vitro constructs were performed. The presence of DPC induced a more regular and multi-layered stratified epidermis with more basal p63-positive cells and invaginations. Graft-take and tissue remodeling in nude mice were favored in DPC-containing composite skin supported by the fact of graft-epidermis survival and early neovascularization. Interestingly, only in grafted constructs containing DPC, embryonic hair bud-like structures were observed from 14 days after grafting. These structures showed cells of human origin, presence of precursor epithelial cells and expression of a hair differentiation marker. These observations suggest an incipient hair follicle neogenesis inside the remodeling ADM. Taken together our results show DPC and HFSC as promising cellular components for a permanent skin substitute.Fil: Leiros, Gustavo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencias y Tecnología "Dr. Cesar Milstein"; ArgentinaFil: Kusinsky, Ana Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencias y Tecnología "Dr. Cesar Milstein"; ArgentinaFil: Drago, Hugo. Hospital de Quemados de la Ciudad de Buenos Aires. Banco de Tejidos; ArgentinaFil: Bossi, Silvia. Hospital de Quemados de la Ciudad de Buenos Aires. Banco de Tejidos; ArgentinaFil: Sturla, Flavio. Hospital de Quemados de la Ciudad de Buenos Aires. Banco de Tejidos; ArgentinaFil: Castellanos, Maria Lia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencias y Tecnología "Dr. Cesar Milstein"; ArgentinaFil: Stella, Inés Yolanda. Universidad Maimónides. Centro de Estudios Biomédicos, Ambientales y Diagnóstico; ArgentinaFil: Balaña, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencias y Tecnología "Dr. Cesar Milstein"; Argentin

Interações entre fatores de crescimento (GFs) e o receptor de progesterona (PR) em câncer de mama

En trabajos previos hemos demostramos la existencia de interacciones bi-direccionales entre las vías de los progestá- genos y de la heregulina (HRG) en cáncer mamario. Encontramos que los progestágenos regulan la actividad y expresión del ErbB-2 y de la HRG. Describimos que la interacción entre la vía de la progesterona y de la HRG ocurre a nivel del PR que es activado transcripcionalmente por la HRG. Además encontramos que los progestágenos inducen la activación transcripcional de la proteína transductora de señales y activadora de la transcripción 3 (Stat3), que es un requisito para el crecimiento inducido por progestágenos en cáncer mamario. Demostramos que Stat3 es un punto de convergencia entre las vías de PR y de HRG/ErbB-2 en cáncer de mama, ya que la HRG, a través del ErbB-2, induce la activación de Stat3 mediante la integración del PR como molécula señalizadora. En línea con estos resultados, describimos la función de Stat3 como coactivador del PR activado por progesterona y como integrante de un complejo transcripcional en donde ErbB-2 actúa como coactivador de Stat3 sobre el promotor de ciclina D1. Estos resultados proveen nuevos blancos moleculares como terapéuticas alternativas para el tratamiento del cáncer de mama resistente a las terapias anti-hormonales y anti-tirosina quinasa.Accumulating findings, including ours, have proven the presence of bidirectional interactions between progestins and heregulin (HRG) signaling pathways in breast cancer. On the one hand, we showed that PR activates the HRG/ErbB-2 pathway. On the other, we found that HRG induces PR transcriptional activation. We have provided the first demonstration that progestins induced transcriptional activation of the signal transducer and activator of transcription 3 (Stat3), which is an absolute requirement for progestin-mediated in vitro and in vivo breast cancer growth. We have identified Stat3 as a convergence point between PR and HRG/ErbB-2 signaling pathways in breast cancer, given that Stat3 is activated by HRG via ErbB-2 and through the co-option of PR function as a signaling molecule. In line with these results, we have described Stat3 as a coactivator of ligand activatedPR and as part of a novel transcriptional complex where ErbB-2 functions as a Stat3 coactivator in progestin-induced cyclin D1 promoter activation. These results provide novel molecular targets as alternative therapies for breast cancer resistant to anti-hormonal and anti-tyrosine kinase therapies.Em trabalhos prévios temos demonstrado a existência de interações bidirecionais entre as vias dos progestágenos e da heregulina (HRG) em câncer mamário. Encontramos que os progestágenos regulam a atividade e expressão do ErbB-2 e da HRG. Descrevemos que a interação entre a via da progesterona e da HRG ocorre em nível do PR que é ativado transcricionalmente pela HRG. Além disso encontramos que os progestágenos induzem a ativação transcricional da proteína transdutora de sinais e ativadora da transcrição 3 (Stat3), que é um requisito para o crescimento induzido por progestágenos em câncer mamário. Demonstramos que Stat3 é um ponto de convergência entre as vias de PR e de HRG/ErbB-2 em câncer de mama, já que a HRG, através do ErbB-2, induz a ativação de Stat3 mediante a integração do PR como molé- cula sinalizadora. Em linha com estes resultados, descrevemos a função de Stat3 como coativador do PR ativado por progesterona e como integrante de um complexo transcricional onde ErbB-2 atua como coativador de Stat3 sobre o promotor de ciclina D1. Estes resultados fornecem novos alvos moleculares como terapêuticas alternativas para o tratamento do câncer de mama resistente às terapias anti-hormonais e anti-tirosina quinase.Fil: Elizalde, Patricia Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Proietti Anastasi, Cecilia Jazmín. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Schillaci, Roxana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Balaña, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Labriola, Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Salatino, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Beguelin, Wendy. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Carnevale, Romina Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Díaz Flaqué, María Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Charreau, Eduardo Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

Metastatic Cancer Stem Cells: New Molecular Targets for Cancer Therapy

The cancer stem cell (CSC) hypothesis, predicts that a small subpopulation of cancer cells that possess "stem-like" characteristics, are responsible for initiating and maintaining cancer growth. According to the CSC model the many cell populations found in a tumour might represent diverse stages of differentiation. From the cellular point of view metastasis is considered a highly inefficient process and only a subset of tumour cells is capable of successfully traversing the entire metastatic cascade and eventually re-initiates tumour growth at distant sites. Some similar features of both normal and malignant stem cells suggest that CSCs are not only responsible for tumorigenesis, but also for metastases. The CSC theory proposes that the ability of a tumour to metastasize is an inherent property of a subset of CSCs. The similar biological characteristics shared by normal stem cells (NSCs) and CSCs mainly implicate self-renewal and differentiation potential, survival ability, niche-specific microenvironment requirements and specific homing to metastatic sites and may have important implications in terms of new approaches to cancer therapy in the metastatic setting. There are several agents targeting many of these CSC features that have shown to be effective both in vitro and in vivo. Although clinical trials results are still preliminary and continue under investigation, these new therapies are very promising. The identification of new therapeutic targets and drugs based on CSC model constitutes a great challenge.Fil: Leiros, Gustavo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología "Dr. César Milstein". Fundación Pablo Cassará. Instituto de Ciencia y Tecnología "Dr. César Milstein"; ArgentinaFil: Balaña, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología "Dr. César Milstein". Fundación Pablo Cassará. Instituto de Ciencia y Tecnología "Dr. César Milstein"; Argentin

Hair follicle stem cell differentiation is inhibited through cross-talk between Wnt/β-catenin and androgen signalling in dermal papilla cells from patients with androgenetic alopecia

Background Hair follicle (HF) regeneration begins when signals from the mesenchyme-derived dermal papilla cells (DPC) reach multipotent epidermal stem cells in the bulge region. Wnt/β-catenin signalling is known to affect mammalian hair growth positively. In androgenetic alopecia (AGA), androgens cause HF miniaturization through a mechanism that remains unclear. Circulating androgens act on DPC and alter paracrine factors that influence hair epithelial cells. Objectives To elucidate the role of androgens in dermal papilla-induced differentiation of HF stem cells. Methods HF stem cell differentiation was evaluated in a coculture model with DPC or culturing with media conditioned by DPC after activation of androgen and Wnt/β-catenin signalling pathways. To study the molecular cross-talk between the androgen and Wnt signalling pathway in DPC, we analysed the expression and activation of downstream Wnt signalling molecules in the presence of androgens. Results In a coculture model with human DPC from patients with AGA and HF stem cells, we observed that androgens abrogate hair differentiation evaluated by hair-specific keratin 6 expression. Wnt signalling activation restored the ability of androgen-treated DPC to induce differentiation. Androgen treatment revealed a significant decrease in the cytoplasmic/total β-catenin protein ratio and upregulation of the activity of glycogen synthase kinase-3β in DPC, indicative of canonical Wnt pathway inhibition. Conclusions These results suggest that androgens deregulate DPC-secreted factors involved in normal HF stem cell differentiation via the inhibition of the canonical Wnt signalling pathway. © 2012 The Authors. BJD © 2012 British Association of Dermatologists.Fil: Leiros, Gustavo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología "Dr. César Milstein". Fundación Pablo Cassará. Instituto de Ciencia y Tecnología ; ArgentinaFil: Attorresi, Alejandra Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología "Dr. César Milstein". Fundación Pablo Cassará. Instituto de Ciencia y Tecnología ; ArgentinaFil: Balaña, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología "Dr. César Milstein". Fundación Pablo Cassará. Instituto de Ciencia y Tecnología ; Argentin

Triolein reduces MMP-1 upregulation in dermal fibroblasts generated by ROS production in UVB-irradiated keratinocytes

Background: Cytokine production and oxidative stress generated by ultraviolet radiation B (UVB) skin exposure are main factors of skin photoaging. Interleukin-6 (IL-6) produced by irradiated keratinocytes is proposed to have a role in metalloproteinases (MMPs) expression activation in dermal fibroblasts. Objectives: We examined the effect of triolein treatment of UVB-irradiated keratinocytes on MMP1 (interstitial collagenase) expression response of dermal fibroblasts. We assayed UVB-irradiated keratinocytes soluble signals, mainly IL-6 and reactive oxygen species (ROS). Methods: IL-6 expression and ROS generation were assayed in UVB-irradiated keratinocytes. MMP1 mRNA expression response was assayed in fibroblasts grown in keratinocytes conditioned medium. We evaluated the effect of treating keratinocytes with triolein on IL-6 expression and ROS generation in keratinocytes, and MMP1 expression in fibroblasts. Results: The irradiation of epidermal cells with sublethal UVB doses increased IL-6 expression and ROS generation. Conditioned culture medium collected from keratinocytes was used to culture dermal fibroblasts. MMP1 mRNA expression increase was observed in fibroblasts cultured in medium collected from UVB-irradiated keratinocytes. Triolein treatment reduced the IL-6 expression and ROS generation in keratinocytes and this effect was reflected in downregulation of MMP1 expression in fibroblasts. Conclusions: Triolein reduces both the expression of IL-6 and ROS generation in irradiated keratinocytes. It seems to exert an anti-inflammatory and anti-oxidative stress effect on irradiated keratinocytes that in turn reduces MMP1 expression in dermal fibroblasts. Collectively, these results indicate that triolein could act as a photoprotective agent.Fil: Leiros, Gustavo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología ; ArgentinaFil: Kusinsky, Ana Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología ; ArgentinaFil: Balaña, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología ; ArgentinaFil: Hagelin, Karin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología ; Argentin

Silencing the androgen receptor: New skills for antiandrogen oligonucleotide skin and hair therapy

Hair growth and follicular cycle are regulated predominantly through androgens under complex genetic and hormonal control. Human hair growth occurs in cycles of three phases, anagen (continuous growth), catagen (cessation of growth) and telogen (resting phase). In genetically susceptible subjects, hair follicles in vertex and frontal regions of the scalp respond to androgens by reducing length of the anagen phase and regression of the follicles producing weaker and thinner hairs. More than 50% of men by the age of 50 years and women over 60 years suffer from androgenetic alopecia. Keywords: Antiandrogen oligonucleotides, Skin and hair, Cutaneous therapyFil: Dugour, Andrea Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología "Dr. César Milstein". Fundación Pablo Cassará. Instituto de Ciencia y Tecnología "Dr. César Milstein"; ArgentinaFil: Hagelin, Karin. Unidad Asistencial "Dr. César Milstein"; ArgentinaFil: Smus, Cintia Natalia. Unidad Asistencial "Dr. César Milstein"; ArgentinaFil: Balaña, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología "Dr. César Milstein". Fundación Pablo Cassará. Instituto de Ciencia y Tecnología "Dr. César Milstein"; ArgentinaFil: Kerner, Néstor. Unidad Asistencial "Dr. César Milstein"; Argentin