La ingeniería biomédica en la UC3M

Los rankings profesionales en las proyecciones del Departamento de Trabajo del gobierno de EE.UU. para el periodo 2008-2018, publicaba en 2010 la lista de las 50 carreras que, en su opinión, ofrecían las mejores oportunidades: en el área de ciencia y tecnología la encabezaba la ingeniería biomédica. Denota que cómo consecuencia del desarrollo del proyecto "Genoma humano", y la creciente capacidad de correlacionar la variabilidad genética de los individuos y su susceptibilidad a las enfermedades y a los fármacos (farmacogenética/farmacogenómica), ha llevado al concepto de ‘medicina personalizada’. El nuevo Grado en Ingeniería Biomédica dirige las especialidades a tres itinerarios específicos: instrumentación médica, imagen médica e ingeniería de tejidos y medicina regenerativa

Long-term Engraftment of Single Genetically Modified Human Epidermal Holoclones Enables Safety Pre-assessment of Cutaneous Gene Therapy

Predicting the risks of permanent gene therapy approaches involving the use of integrative gene-targeting vectors has become a critical issue after the unfortunate episode of a clinical trial in children with X-linked severe combined immunodeficiency (X-SCID). Safety pre-assessment of single isolated gene-targeted stem cells or their derivative clones able to regenerate their tissue of origin would be a major asset in addressing untoward gene therapy effects in advance. Human epidermal stem cells, which have extensive proliferative potential in vitro, theoretically offer such a possibility as a method of assessment. By means of optimized organotypic culture and grafting methods, we demonstrate the long-term in vivo regenerative capacity of single gene-targeted human epidermal stem cell clones (holoclones). Both histopathological analysis of holoclone-derived grafts in immunodeficient mice and retroviral insertion site mapping performed in the holoclone in vitro and after grafting provide proof of the feasibility of pre-assessing genotoxicity risks in isolated stem cells before transplantation into patients. Our results provide an experimental basis for previously untested assumptions about the in vivo behavior of epidermal stem cells prospectively isolated in vitro and pave the way for a safer approach to cutaneous gene therapy

The regenerative potential of fibroblasts in a new diabetes-induced delayed humanised wound healing model

Cutaneous diabetic wounds greatly affect the quality of life of patients, causing a substantial economic impact on the healthcare system. The limited clinical success of conventional treatments is mainly attributed to the lack of knowledge of the pathogenic mechanisms related to chronic ulceration. Therefore, management of diabetic ulcers remains a challenging clinical issue. Within this context, reliable animal models that recapitulate situations of impaired wound healing have become essential. In this study, we established a new in vivo humanised model of delayed wound healing in a diabetic context that reproduces the main features of the human disease. Diabetes was induced by multiple low doses of streptozotocin in bioengineered human-skin-engrafted immunodeficient mice. The significant delay in wound closure exhibited in diabetic wounds was mainly attributed to alterations in the granulation tissue formation and resolution, involving defects in wound bed maturation, vascularisation, inflammatory response and collagen deposition. In the new model, a cell-based wound therapy consisting of the application of plasma-derived fibrin dermal scaffolds containing fibroblasts consistently improved the healing response by triggering granulation tissue maturation and further providing a suitable matrix for migrating keratinocytes during wound re-epithelialisation. The present preclinical wound healing model was able to shed light on the biological processes responsible for the improvement achieved, and these findings can be extended for designing new therapeutic approaches with clinical relevance.This work was supported by grants from the Science and Innovation Ministry of Spain (SAF2010-16976), from the European VI Framework Programme (LSHB-CT-512102), from Comunidad de Madrid (S2010/BMD-2420; CELLCAM) and from Fundacion Ramon Areces (CIVP16A1864)

La terapia génica ante el nuevo milenio

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Increased IKKα Expression in the Basal Layer of the Epidermis of Transgenic Mice Enhances the Malignant Potential of Skin Tumors

Non-melanoma skin cancer is the most frequent type of cancer in humans. In this study we demonstrate that elevated IKKα expression in murine epidermis increases the malignancy potential of skin tumors. We describe the generation of transgenic mice overexpressing IKKα in the basal, proliferative layer of the epidermis and in the outer root sheath of hair follicles. The epidermis of K5-IKKα transgenic animals shows several alterations such as hyperproliferation, mislocalized expression of integrin-α6 and downregulation of the tumor suppressor maspin. Treatment of the back skin of mice with the mitogenic agent 12-O-tetradecanoylphorbol-13-acetate causes in transgenic mice the appearance of different preneoplastic changes such as epidermal atypia with loss of cell polarity and altered epidermal tissue architecture, while in wild type littermates this treatment only leads to the development of benign epidermal hyperplasia. Moreover, in skin carcinogenesis assays, transgenic mice carrying active Ha-ras (K5-IKKα-Tg.AC mice) develop invasive tumors, instead of the benign papillomas arising in wild type-Tg-AC mice also bearing an active Ha-ras. Therefore we provide evidence for a tumor promoter role of IKKα in skin cancer, similarly to what occurs in other neoplasias, including hepatocarcinomas and breast, prostate and colorectal cancer. The altered expression of cyclin D1, maspin and integrin-α6 in skin of transgenic mice provides, at least in part, the molecular bases for the increased malignant potential found in the K5-IKKα skin tumors

Exocrine pancreatic disorders in transsgenic mice expressing human keratin 8

9 pages, 6 figures, 2 tables.-- et al.Keratins K8 and K18 are the major components of the intermediate-filament cytoskeleton of simple epithelia. Increased levels of these keratins have been correlated with various tumor cell characteristics, including progression to malignancy, invasive behavior, and drug sensitivity, although a role for K8/K18 in tumorigenesis has not yet been demonstrated. To examine the function of these keratins, we generated mice expressing the human K8 (hk8) gene, which leads to a moderate keratin-content increase in their simple epithelia. These mice displayed progressive exocrine pancreas alterations, including dysplasia and loss of acinar architecture, redifferentiation of acinar to ductal cells, inflammation, fibrosis, and substitution of exocrine by adipose tissue, as well as increased cell proliferation and apoptosis. Histological changes were not observed in other simple epithelia, such as the liver. Electron microscopy showed that transgenic acinar cells have keratins organized in abundant filament bundles dispersed throughout the cytoplasm, in contrast to control acinar cells, which have scarce and apically concentrated filaments. The phenotype found was very similar to that reported for transgenic mice expressing a dominant-negative mutant TGF-β type II receptor (TGFβRII mice). We show that these TGFβRII mutant mice also have elevated K8/K18 levels. These results indicate that simple epithelial keratins play a relevant role in the regulation of exocrine pancreas homeostasis and support the idea that disruption of mechanisms that normally regulate keratin expression in vivo could be related to inflammatory and neoplastic pancreatic disorders.This work was supported in part by grant PB 94-1230 of the Spanish Dirección General de Investigación Científica y Tecnológica.Peer reviewe

Up-regulation of vascular endothelial growth factor/vascular permeability factor in mouse skin carcinogenesis correlates with malignant progression state and activated H-ras expression levels

Angiogenesis is a crucial process for tumor growth and metastasis regulated by the balance of positive and negative factors. Vascular endothelial growth factor (VEGF/VPF) is a specific mitogen for endothelial cells that has been shown to be overexpressed in a variety of tumors and other inflammatory diseases. To analyze the implication of VEGF/VPF during tumorigenesis, we have studied its expression at different stages of tumor development using the mouse skin carcinogenesis model. VEGF/VPF mRNA was induced in skin in vivo after 12-O-tetradecanoylphorbol-13-acetate treatment. Constitutive up-regulation of VEGF/VPF at the mRNA and protein levels was also observed in premalignant papillomas and, at a higher level, in squamous carcinomas, suggesting a correlation between VEGF/VIF expression and tumor progression. A direct positive correlation between VEGF/VPF mRNA expression and the level of activated H-ras gene was found in a series of cell lines representing different stares of epidermal tumor development. Consequently, a clone of line of these cell lines, HaCa4, which has lost most of its v-ras expression, down-regulated VEGF mRNA expression concomitantly with its metastatic potential. Direct evidence of H-ras involvement in VEGF induction was obtained when an immortalized mouse keratinocyte cell line transduced with a retrovirus carrying v-H-ras showed highly increased VEGF/VPF mRNA levels. These data show that in mouse skin carcinogenesis, the VEGF/VPF angiogenic stimulus occurs early during premalignant papilloma development and further increases at later stages. Moreover, we demonstrate that increasing the activated H-ras dose, a phenomenon that takes place sequentially throughout mouse skin tumor development, may play an additional role by facilitating malignant in vivo progression through the modulation of VEGF/VPF-mediated angiogenesis.This work was supported in part by Grants PB9O-0390 and PB94- 1 230 from the Dirección General de Investigaciones Científicas of Spain (to J. L. J.) and CA57596 from NIH. R. M. was supported by a fellowship from the Spanish Ministerio de Educacióny Ciencia.Peer Reviewe

Remote diffuse reflectance spectroscopy sensor for tissue engineering monitoring based on blind signal separation

et al.In this study the first results on evaluation and assessment of grafted bioengineered skin substitutes using an optical Diffuse Reflectance Spectroscopy (DRS) system with a remote optical probe are shown. The proposed system is able to detect early vascularization of skin substitutes expressing the Vascular Endothelial Growth Factor (VEGF) protein compared to normal grafts, even though devitalized skin is used to protect the grafts. Given the particularities of the biological problem, data analysis is performed using two Blind Signal Separation (BSS) methods: Principal Component Analysis (PCA) and Independent Component Analysis (ICA). These preliminary results are the first step towards point-of-care diagnostics for skin implants early assessment.Peer reviewe