Guembe, L. (L.)
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- Repigmentation of vitiligo by transplantation of autologous melanocyte cells cultured on amniotic membrane(Wiley-Blackwell, 2008) Garcia-Guzman, M. (María); Olmo-López, J. (Julio) del; Guembe, L. (L.); Redondo-Bellón, P. (Pedro); Prosper-Cardoso, F. (Felipe)SIR, Vitiligo is an acquired skin disease that affects 1% of the world’s population, and which significantly impacts the quality of life of patients. In patients with stable vitiligo, lack of effective medical therapies has led to the development of surgical treatment options using transplantation of autologous melanocytes. These techniques include split-thickness grafts, punch grafts and suction blister grafts, that do not require cell expansion.1,2 Transplantation methods include cultured mixed melanocyte–keratinocyte suspension with or without carrier, and cultured pure melanocyte suspension.3,4 To date, pure single-layer melanocyte cultures have not been reported in the treatment of vitiligo, nor has the use of amniotic membrane (AM) as a scaffold been documented. The AM, the inner part of the placenta, consists of a thick basement membrane of collagen type IV and laminin, and an avascular stroma. AM has been successfully used in skin transplantation5 and has been applied for ocular surface reconstruction in patients with severe corneal diseases.6 We treated a group of five patients (four men and one woman; age range 18–56 years, mean ± SD 29 ± 13Æ2) with either focal or generalized stable vitiligo using a graft of autologous melanocytes cultured on a denuded AM (Table 1). The technique of human amniotic processing and cryopreservation with Dulbecco’s modified Eagle’s medium and 50% glycerol recommended by the U.S. Food and Drug Administration renders all the amniotic cells nonviable.7 Immediately before use, AM was treated with 0Æ02% ethylenediamine
- Comparative study of PrPc expression in rat, monkey and cow gastrointestinal tract(Wiley-Blackwell, 2006-01-12) Sesma, M.P. (María Pilar); Marcos, Z. (Z.); Guembe, L. (L.)ABSTRACT: The gastrointestinal tract (GIT) appears to be the main site of entry for the pathological isoform of prions (PrPsc). To understand how the PrPsc internalization process occurs, it is important to characterize the cell types that express normal prion protein (PrPc) along the GIT. To do so, we studied the distribution of PrPc in the rat, monkey, and cow GIT. Using Western blot analysis, we found that PrPc is expressed in all digestive regions of the three species. Immunoreactivity for PrPc was found throughout the GIT in epithelial cells sharing the neuroendocrine (NE) phenotype. Immunostained cells appeared scattered throughout the epithelium of fundic and pyloric glands as well as in intestinal villi and crypts.
- Hepatitis C virus induces the expression of CCL17 and CCL22 chemokines that attract regulatory T cells to the site of infection(Elsevier, 2011-03-03) Riezu-Boj, J.I. (José Ignacio); Echeverria, I. (Itziar); Larrea, E. (Esther); Aldabe, R. (Rafael); Sangro, B. (Bruno); Casares, N. (Noelia); Guembe, L. (L.); Prieto, J. (Jesús); Galeano, E. (E.); Herrero, J.I. (José Ignacio); Sarobe, P. (Pablo); Lasarte, J.J. (Juan José)Background & Aims: The mechanisms by which Foxp3+ T regulatory cells (Treg) accumulate in HCV infected livers are not known. Here, we studied the role of chemokines CCL17 and CCL22 in this process. Methods: Chemokine mRNA levels were determined by qPCR in liver biopsies from 26 HCV chronically infected patients (CHC), 11 patients with treatment-induced sustained virological response (SVR), 16 patients with other liver diseases unrelated to HCV, and 24 normal livers. Double-immunofluorescence Foxp3/CD3 or CD11c/CCL22 was performed in liver sections. Chemokine production by monocyte-derived dendritic cells (MDDC) co-cultured with uninfected or HCV-JFH1 infected Huh7 cells was measured by qPCR and ELISA. Chemotactic activity of culture supernatants was also tested. Results: Foxp3+ Treg were increased in CHC livers as compared to controls. Patients with CHC showed elevated intrahepatic levels of CCL17 mRNA compared to normal livers or livers from subjects with SVR or other forms of liver disease. Intrahepatic CCL22 expression was also higher in CHC than in healthy subjects or SVR patients but similar to that observed in other liver diseases. Dendritic cells producing CCL22 could be found inside the hepatic lobule in CHC patients. Contact between MDDC and HCV-JFH1- infected Huh7 cells induced the expression of CCL17 and CCL22 in a process partially dependent on ICAM-1. Transwell experiments showed that upregulation of these chemokines enhanced Treg migration
- The diffuse endocrine system: from embryogenesis to carcinogenesis(Elsevier, 2003) Sesma, M.P. (María Pilar); Villaro, A.C. (Ana Cristina); Burrell, M.A. (María Ángela); Montuenga-Badia, L.M. (Luis M.); Guembe, L. (L.); Bodegas-Frías, E. (Elena); Calvo-González, A. (Alfonso); Sola, J.J. (Jesús Javier)In the present review we will summarise the current knowledge about the cells comprising the Diffuse Endocrine System (DES) in mammalian organs. We will describe the morphological, histochemical and functional traits of these cells in three major systems gastrointestinal, respiratory and prostatic. We will also focus on some aspects of their ontogeny and differentiation, as well as to their relevance in carcinogenesis, especially in neuroendocrine tumors. The first chapter describes the characteristics of DES cells and some of their specific biological and biochemical traits. The second chapter deals with DES in the gastrointestinal organs, with special reference to the new data on the differentiation mechanisms that leads to the appearance of endocrine cells from an undifferentiated stem cell. The third chapter is devoted to DES of the respiratory system and some aspects of its biological role, both, during development and adulthood. Neuroendocrine hyperplasia and neuroendocrine lung tumors are also addressed. Finally, the last chapter deals with the prostatic DES, discussing its probable functional role and its relevance in hormone-resistant prostatic carcinomas.
- Production of regulatory factors in the respiratory system of vertebrates(Brill Academic Publishers, 1994) Sesma, M.P. (María Pilar); Villaro, A.C. (Ana Cristina); Montuenga-Badia, L.M. (Luis M.); Guembe, L. (L.); Bodegas-Frías, E. (Elena); Beorlegui, C. (Carmen)Among the different cell types present in the respiratory tract of the vertebrates, some (epithelial, endothelial, neural) specialise in the production of regulatory factors. Endocrine cells occur either single, spread throughout the epithelial lining, or in innervated groups, called 'neuroepithelial bodies' (NEBs). In mammals, these endocrine cells may be involved in lung maturation during perinatal life and in chemoreception. A neuroendocrine diffuse system is present in the respiratory organs of all classes of vertebrates. In amphibians and reptiles, single endocrine cells as well as NEBs are located in the apices of the lung septa. The respiratory tract shows nerve fibres immunoreactive to several neuropeptides. Since some neurons and fibres contain NO synthase a broad evolutionary presence of NO-releasing neurons, probably involved in the control of relaxation, is suggested.
- Distribution of the long leptin receptor isoform in brush border, basolateral membrane, and cytoplasm of enterocytes.(British Society of Gastroenterology, 2002) Pascual, I. (I.); Villaro, A.C. (Ana Cristina); Muñoz-Navas, M. (Miguel); Lostao, M.P. (María Pilar); Barber, A. (Ana); Guembe, L. (L.); Barrenetxe, J. (Jaione)BACKGROUND AND AIM: Leptin, a hormone mainly produced by fat cells, acts primarily on the hypothalamus regulating energy expenditure and food intake. Leptin receptors are expressed in several tissues and the possible physiological role of leptin is being extensively investigated, with the result that important peripheral actions of the hormone in the organism are being discovered. Recent studies have demonstrated leptin and leptin receptor expression in gastric epithelial cells. In the present study, we report the presence of the long leptin receptor isoform (OB-Rb) in human, rat, and mouse small intestine, supporting the hypothesis of leptin as a hormone involved in gastrointestinal function. METHODS: The presence of the leptin receptor was determined by immunocytochemical methods using antibodies against the peptide corresponding to the carboxy terminus of the long isoform of the leptin receptor. Human duodenal biopsies from normal individuals undergoing gastrointestinal endoscopy, and intestinal fragments of Wistar rats and Swiss mice were processed for the study. RESULTS: Immunoreactivity for the long leptin receptor isoform was observed in the three studied species. Staining was located throughout the cytoplasm of the enterocytes, of both villi and crypts, and in the basolateral plasma membrane. Immunolabelling for OB-Rb protein was also found in the brush border of human enterocytes of formol and paraformaldehyde fixed samples. CONCLUSION: This report demonstrates the presence of the long leptin receptor isoform in the absorptive cells of rat, mouse, and human small intestine, suggesting that leptin could have a physiological role in the regulation of nutrient absorption.
- A peptide inhibitor of FOXP3 impairs regulatory T cell Activity and improves vaccine efficacy in mice(American Association of Immunologists, 2010-11-25) Riezu-Boj, J.I. (José Ignacio); Borras-Cuesta, F. (Francisco); Lozano-Moreda, T. (Teresa); Rudilla, F. (Francesc); Casares, N. (Noelia); Guembe, L. (L.); Prieto, J. (Jesús); Llopiz, D. (Diana); Sarobe, P. (Pablo); Arribillaga, L. (Laura); Lopez-Sagaseta, J. (Jacinto); Lasarte, J.J. (Juan José)Immunosuppressive activity of regulatory T cells (Treg) may contribute to the progression of cancer or infectious diseases by preventing the induction of specific immune responses. Using a phage-displayed random peptide library, we identified a 15-mer synthetic peptide, P60, able to bind to forkhead/winged helix transcription factor 3 (FOXP3), a factor required for development and function of Treg. P60 enters the cells, inhibits FOXP3 nuclear translocation, and reduces its ability to suppress the transcription factors NF-κB and NFAT. In vitro, P60 inhibited murine and human-derived Treg and improved effector T cell stimulation. P60 administration to newborn mice induced a lymphoproliferative autoimmune syndrome resembling the reported pathology in scurfy mice lacking functional Foxp3. However, P60 did not cause toxic effects in adult mice and, when given to BALB/c mice immunized with the cytotoxic T cell epitope AH1 from CT26 tumor cells, it induced protection against tumor implantation. Similarly, P60 improved the antiviral efficacy of a recombinant adenovirus expressing NS3 protein from hepatitis C virus. Functional inhibition of Treg by the FOXP3-inhibitory peptide P60 constitutes a strategy to enhance antitumor and antiviral immunotherapies.
- Adeno-associated virus liver transduction efficiency measured by in vivo [18F]FHBG positron emission tomography imaging in rodents and nonhuman primates(Mary Ann Liebert, 2011) González-Aseguinolaza, G. (Gloria); Benito-Boilos, A. (Alberto); Snapper, J. (Jolanda); Collantes, M. (María); Lanciego, J.L. (José Luis); Peñuelas-Sanchez, I. (Ivan); Timmermans, E. (Eric); Pañeda, A. (Astrid); Rodriguez-Pena, M.S. (María Sol); Otano, I. (Itziar); Guembe, L. (L.); Beattie, S.G. (Stuart G.); Prieto, J. (Jesús)Recombinant adeno-associated virus 5 (rAAV5) represents a candidate vector with unique advantages for the treatment of hepatic disorders because of its narrow hepatic tropism. Noninvasive in vivo imaging of transgene expression provides an important tool with which to quantify the transduction efficiency, and duration and location, of transgene expression. In this study, we used positron emission tomography (PET) and positron emission tomography-computed tomography (PET-CT) imaging to monitor liver transduction efficacy in rodents and nonhuman primates that received rAAV5 vector encoding herpes simplex virus thymidine kinase (HSV-TK). HSV-TK expression in liver was also measured by immunohistochemistry. Notable differences in liver transduction efficiency were found, dependent on the animal species and sex. Male rodents were better transduced than females, as previously described. Moreover, male nonhuman primates also displayed increased hepatic expression of the rAAV5-delivered transgene, indicating that differences in rAAV-mediated liver transduction can be anticipated in humans. Our results demonstrate the high sensitivity and reproducibility of PET, using HSV-TK and [(18)F]FHBG, to detect gene expression after rAAV vector administration into living animals, confirming the utility of this technology in the quantification of transgene expression, even at low expression levels. However, we also describe how an immune response against HSV-TK hampered analysis of long-term expression in nonhuman primates.