Cristina Touriño - Academia.edu (original) (raw)

Papers by Cristina Touriño

Arquivos Brasileiros De Cardiologia, Dec 1, 2011

The process of angiogenesis involves a complex sequence of stimuli and integrated responses, such... more The process of angiogenesis involves a complex sequence of stimuli and integrated responses, such as stimulation of endothelial cells (ECs) for their proliferation and migration, stimulation of the extracellular matrix (ECM) for the attraction of pericytes and macrophages, stimulation of smooth muscle cells for their proliferation and migration, and formation of new vascular structures. Angiogenesis is mainly an adaptive response to tissue hypoxia and depends on the accumulation of the hypoxiainducible factor (HIF-1α) in the ischemic myocardial area, which increases the transcription of the vascular endothelial growth factor (VEGF) and its receptors VEGF-R by the ECs undergoing ischemia. Those steps involve enzymatic mechanisms and plasminogen activator proteases, metalloproteinases (MMP) of the ECM, and kinases that cause proteolytic molecular degradation of the ECM and activation and release of growth factors, such as: basic fibroblast growth factor (bFGF), VEGF, and insulin growth factor-1 (IGF-1). In the intermediate phase, stabilization of the immature neovascular sprout occurs. The final phase is characterized by vascular maturation of the physiological angiogenesis. In conclusion, coronary angiogenesis in adults is fundamentally a paracrine response of the preexisting capillary network under pathophysiological condition of ischemia and inflammation.

Hématologie, Mar 18, 1999

En l’absence de caracteristiques morphologiques ou immunologiques specifiques, les progeniteurs h... more En l’absence de caracteristiques morphologiques ou immunologiques specifiques, les progeniteurs hematopoietiques humains ne peuvent etre identifies que sur la caracterisation de leur descendance obtenue in vitro apres induction de leur proliferation et de leur differenciation dans des conditions appropriees. La limitation dans le temps et le caractere tres artificiel des tests in vitro, qui ne peuvent pas mimer les conditions de fonctionnement d’un organisme entier, les rendent peu propices a l’identification des cellules souches responsables de la reconstitution hematopoietique apres greffe, et a l’evaluation d’une atteinte quantitative ou qualitative de ce compartiment. Ceci explique les efforts entrepris pour creer un modele experimental in vivo ou les cellules humaines pourraient s’implanter et se developper dans la moelle osseuse d’un receveur xenogenique, reconstituant une hematopoiese active pendant plusieurs mois. L’objectif de cette revue (la troisieme de la serie) est de faire le point de nos connaissances sur le modele developpe par Dick qui consiste a injecter des populations de cellules souches humaines par voie intraveineuse a des souris immunodeficientes (SCID/NOD-SCID) et a analyser leur developpement dans les tissus murins plusieurs semaines apres greffe. Nous nous efforcerons d’analyser de facon critique si cette strategie permet une evaluation rigoureuse du compartiment des cellules souches hematopoietiques humaines, et en quoi elle peut faire progresser notre connaissance du fonctionnement de ces cellules. (Cette revue fait suite a deux articles parus anterieurement dans Hematologie et traitant des modeles animaux d’analyse de l’hematopoiese humaine normale I) Zanjani et al., Hematologie 1996 ; 2 : 487-98 et II) Peault et al., Hematologie 1997 ; 3 : 299-307.)

Stem Cell Investigation

Background: The use of a deceased donor (DD) as an alternative source of human mesenchymal stroma... more Background: The use of a deceased donor (DD) as an alternative source of human mesenchymal stromal cells (hMSC) is promising, but has been little explored. This study evaluated the potential of femur bone marrow (FBM) from brain-death donors as a source of hMSC and compared this with hMSC from matched iliac crest bone marrow (ICBM). Methods: Sixteen donor-matched FBM and ICBM samples were processed from brain-death donors. We analyzed the starting material and compared cell yield, phenotypic profile and differentiation capacity of hMSC. Results: Neither the amount of nucleated cells per gram (14.6×10 6 ±10.3×10 6 from FBM vs.

The Hematology Journal, 2001

The ex vivo expansion of hematopoietic grafts could be an important therapeutic tool for accelera... more The ex vivo expansion of hematopoietic grafts could be an important therapeutic tool for accelerating hematopoietic recovery after administration of high-dose chemotherapy regimens. The fate of the long-term repopulating cells during the ex vivo manipulation of grafts is a critical issue and will ultimately define the clinical applicability of this technology to hematopoietic transplantation. To study the effects of a clinically applicable ex vivo expansion protocol in the proliferative potential of the most primitive human hematopoietic cells, both LTC-IC and NOD/SCID-RC assays were used to determine LTC-IC and NOD/SCID-RC contents of hematopoietic grafts, both before and after expansion (SCF, IL-3, PEG-MGDF Flt3-L and 5% AB serum), in four children with non-hematological malignancies. The mean percentage of CD34+ cells after expansion was 16%. The numbers of nucleated cells increased 20-fold with a mean three-fold increase in the numbers of CD34+ cells during the expansion period. The CFC content of the samples showed a mean 11-fold increase (range: 5-17) after ex vivo expansion. The primitive hematopoietic stem cell content of the expanded cell fraction evaluated by LTC-IC assays was found to be increased in two patients out of three, with maintenance of the LTC-IC frequency in the third patient. The NOD/SCID-RC potential, evaluated in five experiments from four patients using 109 mice injected 5-6 weeks earlier with human hematopoietic cells, increased from a mean percentage of 36% (range: 7-75%) before expansion, to a mean percentage of 70% (range: 37-100%) after expansion (P < 0.00001). The frequency of NOD/SCID-RC calculated with pooled data from all patients was 1/80,000 at day 0 and 1/40,000 after seven days of culture. The full phenotypic analysis of human hematopoietic cells obtained in NOD/SCID mice injected with expanded cells showed the presence of significant numbers of CD34+, CD19+ and CD15+ cells, suggesting the persistent lympho-myeloid potential of the expanded hematopoietic cells. Our results suggest that efficient expansion of NOD/SCID-RC with lympho-myeloid potential can be achieved not only in cord blood or normal marrow as previously reported, but also in hematopoietic grafts obtained from children exposed to high-dose chemotherapy.

Introduction: The ex vivo expansion of hematopoietic grafts could be an important therapeutic too... more Introduction: The ex vivo expansion of hematopoietic grafts could be an important therapeutic tool for accelerating hematopoietic recovery after administration of high-dose chemotherapy regimens. The fate of the long-term repopulating cells during the ex vivo manipulation of grafts is a critical issue and will ultimately define the clinical applicability of this technology to hematopoietic transplantation. Materials and methods: To study

Hématologie, 1999

Résumé: En l'absence de caractéristiques morphologiques ou immunologiques spécifiques, les p... more Résumé: En l'absence de caractéristiques morphologiques ou immunologiques spécifiques, les progéniteurs hématopoïétiques humains ne peuvent être identifiés que sur la caractérisation de leur descendance obtenue in vitro après induction de leur prolifération ...

Oncogene, 2005

Myelodysplastic syndromes (MDS) are clonal malignant stem cell disorders characterized by ineffic... more Myelodysplastic syndromes (MDS) are clonal malignant stem cell disorders characterized by inefficient hematopoiesis. The role of the marrow microenvironment in the pathogenesis of the disease has been controversial and no study has been performed so far to characterize mesenchymal cells (MC) from MDS patients and to analyse their ability to support hematopoiesis. To this end, we have isolated and characterized MC at diagnostic marrow samples (n ¼ 12) and have purified their CD34 þ CD38À and CD34 þ CD38 þ counterparts (n ¼ 7) before using MC as a short-and long-term hematopoietic support. We show that MC can be readily isolated from MDS marrow and exhibit a major expansion potential as well as an intact osteoblastic differentiation ability. They do not harbor the abnormal marker identified by FISH in the hematopoietic cells and they stimulate the growth of autologous clonogenic cells. Conversely, highly purified stem cells and their cytokine-expanded progeny harbor the clonal marker with variable frequencies, and both normal and abnormal long-term culture-initiating cell-derived progeny can be effectively supported by autologous MC. Thus, we demonstrate that MDS marrow is an abundant source of MC appearing both cytogenetically and functionally noninvolved by the malignant process and able to support hematopoiesis, suggesting their possible usefulness in future cell therapy approaches.

Archivos De Medicina Interna, 2006

Blood, 1999

Evidence has been provided recently that shows that high concentrations of cytokines can fulfill ... more Evidence has been provided recently that shows that high concentrations of cytokines can fulfill functions previously attributed to stromal cells, such as promote the survival of, and led to a net increase in human primitive progenitors initiating long-term cultures in vitro (LTC-IC) or engrafting NOD-SCID (nonobese diabetic severe-combined immunodeficient) recipients in vivo. These data prompted us to re-evaluate whether stromal cells will further alter the properties of primitive progenitor cells exposed to cytokines. Single CD34+CD38low and CD38neg cells were incubated 10 days in serum-containing or serum-free medium in the presence or in the absence of murine marrow-derived stromal cells (MS-5). Recombinant human cytokines stem cell factor (SCF), pegylated-megakaryocyte growth and differentiation factor (PEG–MGDF), FLT3-L, Interleukin (IL)-3, IL-6, and granulocyte-macrophage colony-stimulating factor (GM–CSF) were systematically added at various concentrations (10 to 300 ng/mL)....

Objectives: To establish and implement a simplified protocol for the extraction, primary isolatio... more Objectives: To establish and implement a simplified protocol for the extraction, primary isolation, and culture of human dental pulp stem cells (hDPSCs). To analyze the isolated cells quantitatively and qualitatively. Methodology: Ten healthy third molars were donated by patients who attended the School of Dentistry, UdelaR, and gave their written consent. The teeth were processed within 48 hours. The teeth were sectioned to obtain the pulp tissue and processed with the explant method. Cell viability and marker expression were analyzed by flow cytometry at passages 4 and 12 and verified by immunocytochemistry. Results: The cells obtained had a vitality greater than 90% in all passages. We found the characteristic morphology and the expression of CD90, C105, CD73, CD29 and 166 mesenchymal stem cell markers by flow cytometry in both passages. Conclusion: It was possible to establish a cell isolation protocol that is highly successful and safe to isolate hDPSC.

DNA). Therefore, using NMA rather than DMSO is expected to attenuate cell death due to cryopreser... more DNA). Therefore, using NMA rather than DMSO is expected to attenuate cell death due to cryopreservation, both by ensuring sufficient cryopreservation action and by reducing cytotoxicity. From comparison of activities between pig sperms cryopreserved with 15% (w/v) of NMA, NMF, and DMSO before freezing and after thawing, freezinginduced damage and cryopreservative-induced cytotoxicity were better with NMA and NMF than with DMSO in contrast to the fact that NMF did not exhibit sufficient cryopreservation activity for human cells.

Cell and Tissue Banking, 2021

Tissue engineering (TE) and regenerative medicine offer strategies to improve damaged tissues by ... more Tissue engineering (TE) and regenerative medicine offer strategies to improve damaged tissues by using scaffolds and cells. The use of collagen-based biomaterials in the field of TE has been intensively growing over the past decades. Mesenchymal stromal cells (MSCs) and dental pulp stem cells (DPSCs) are promising cell candidates for development of clinical composites. In this study, we proposed the development of a bovine collagen type I: chondroitin-6-sulphate (CG) scaffold, obtained from Uruguayan raw material (certified as free bovine spongiform encephalopathy), with CG crosslinking enhancement using different gamma radiation doses. Structural, biomechanical and chemical characteristics of the scaffolds were assessed by Scanning Electron Microscopy, axial tensile tests, FT-IR and Raman Spectroscopy, respectively. Once we selected the most appropriate scaffold for future use as a TE product, we studied the behavior of MSCs and DPSCs cultured on the scaffold by cytotoxicity, proliferation and differentiation assays. Among the diverse porous scaffolds obtained, the one with the most adequate properties was the one exposed to 15 kGy of gamma radiation. This radiation dose contributed to the crosslinking of molecules, to the formation of new bonds and/or to the reorganization of the collagen fibers. The selected scaffold was non-cytotoxic for the tested cells and a suitable substrate for cell proliferation. Furthermore, the scaffold allowed MSCs differentiation to osteogenic, chondrogenic, and adipogenic lineages. Thus, this work shows a promising approach to the synthesis of a collagen-scaffold suitable for TE.

Revista Uruguaya de Medicina Interna, 2018

Rev. urug. med. interna. Caso clinico Tratamiento complementario de heridas crónicas con factor d... more Rev. urug. med. interna. Caso clinico Tratamiento complementario de heridas crónicas con factor de crecimiento estimulante de colonias de granulocitos. A propósito de dos casos clínicos. Granulocyte Colony-Stimulating Growth Factor complementary treatment in chronic wounds. Report of two cases. Tratamento complementar de feridas crônicas com colônias de granulócitos estimulantes do fator de crescimento. Cerca de dois casos clínicos. Resumen: Introducción. Independientemente de su etiología, las heridas crónicas, representan un desafío terapéutico debido a que muchas veces son refractarias a tratamientos convencionales. Es por este motivo que en los últimos años se han desarrollado de forma creciente estrategias complementarias en el área de la medicina regenerativa, como: terapias con células madre, ingeniería de tejidos, plasma rico en plaquetas y factores de crecimiento aplicados en las heridas crónicas. Dichas terapias complementarias han mostrado ciertos beneficios en la cicatrización de heridas complejas. Materiales y métodos. Se presentan dos casos clínicos de pacientes con heridas crónicas de diferente etiología, refractarias al tratamiento con cura avanzada de heridas, las cuales recibieron de forma complementaria factor estimulante de colonias de granulocitos (G-CSF; Filgen®). Se realizaron inyecciones locales de G-CSF a una dosis de 300 mcg/ml en piel peri úlcera en forma semanal completando dos series de cuatro inyecciones cada una. Resultados. Ambos casos presentaron una reducción en el área de las mismas alcanzándose la cicatrización total en un paciente y una reducción del 37% en el otro luego de dos series. El procedimiento fue bien tolerado y no se reportaron efectos adversos relacionados al mismo. Conclusiones. Los resultados obtenidos en estos pacientes mostraron beneficios en la cicatrización con la aplicación del G-CSF. Se requieren de ensayos clínicos controlados que permitan establecer el rol de dicho factor en el tratamiento de las mismas. Por este motivo nuestro grupo de trabajo se encuentra desarrollando un protocolo que permita evaluar este aspecto.

Odontoestomatología, 2021

Establishment and implementation of a simplified protocol for expansion and culture of Human Dent... more Establishment and implementation of a simplified protocol for expansion and culture of Human Dental Pulp Stem Cells (DPSCh) Estabelecimento e implementação de um protocolo simplificado para expansão e cultura de células-tronco da polpa dentária humana (DPSCh)

Muscles, ligaments and tendons journal, 2012

Stem cells are one of the most fascinating areas in regenerative medicine today. They play a cruc... more Stem cells are one of the most fascinating areas in regenerative medicine today. They play a crucial role in development and regeneration and are defined as cells that continuously reproduce themselves while maintaining the ability to differentiate into various cell types. Stem cells are found at all developmental stages, from embryonic stem cells (ESCs) which differentiate into all cell types, to adult stem cells (ASCs) which are responsible for tissue regeneration. Studies using animal models have shown promising results following cell therapy for induced injury in musculoskeletal system, including tendon healing, but the results can be variable. Alternative sources for cell therapy in tendon pathology may include ESCs, ASCs (bone marrow, adipose tissue or tendon derived stem cells) or induced pluripotent stem cells (iPSCs). While ethical and safety concerns currently forbid clinical application of ESCs and iPSCs, initial clinical trials with ASCs are promising.