Efecto del Medio Condicionado de la Línea Celular H9C2 Tratada con Dehidroepiandrosterona y Expuesta a Daño sobre la Motilidad de Células Troncales Mesenquimales / Effect of the Conditioned Medium from H9C2 Cell Line Treated with Dehydroepiandrosterone and Exposed to Damage on the Motility of Mesenchymal Stem Cells

RESUMEN: Las enfermedades cardiovasculares (ECV) son la principal causa de muerte a nivel mundial, donde la terapia con Células Troncales Mesenquimales (CTM) representa una alternativa para los pacientes que no logran recuperarse con los tratamientos actuales. El lograr que las CTM residentes se movilicen al órgano afectado representaría una ventaja para el manejo terapéutico de las ECV. La dehidroepiandrosterona (DHEA) es un precursor hormonal cuyos niveles disminuyen a lo largo de la vida, lo que se ha asociado al desarrollo de ECV. Diversos estudios han demostrado que el consumo de DHEA previene y mejora la condición cardiaca, aunque no se sabe si esto ocurre porque se ejerce un efecto en los cardiomiocitos y estos, a su vez, hacia las CTM. El objetivo del presente estudio fue determinar el efecto del medio condicionado procedente de la línea H9C2 pretratada con DHEA y sometida a daño, sobre la motilidad de CTM, llevando a cabo un ensayo de cierre de herida. El pretratamiento con DHEA y el daño en la línea H9C2, promueve la motilidad de CTM. El estímulo de la motilidad de CTM por un efecto indirecto de DHEA podría ser una estrategia terapéutica para el daño cardiaco.

ABSTRACT: Cardiovascular diseases (CVD) are the leading cause of death worldwide. Mesenchymal Stem Cell (MSC) therapy is an alternative for patients who cannot recover with current treatments. Ensure movilization of MSC to the affected organs would represent an advantage for therapeutic management of CVD. Dehydroepiandrosterone (DHEA) is a hormone precursor whose levels decrease throughout life, which has been associated with the onset of CVD. Several studies have shown that DHEA consumption, prevents and improves heart condition, although it is not known if this is because an effect on cardiomyocytes is exercised on these cells and this, in turn, to CTM. The aim of this study was to determine the effect of conditioned medium from H9C2 cell line pretreated with DHEA and subjected to damage, on the motility of CTM, performing a wound healing assay. Pretreatment with DHEA and damage to H9C2 cell line, promotes motility of CTM. Stimulation of CTM motility by an indirect effect of DHEA could be a therapeutic strategy for heart damage.

Comparación entre Células Troncales Mesenquimales obtenidas de Médula Ósea, Tejido Adiposo y Gelatina de Wharton en base a los Criterios de la ISCT / Comparison between Mesenchymal Stem Cells obtained from Bone Marrow, Adipose Tissue and Wharton Gelatin according to the ISCT Criteria

RESUMEN: Las células troncales mesenquimales (CTM) representan una población heterogénea con capacidad para auto-renovarse y diferenciarse a distintos tipos celulares. Estas fueron descritas en un inicio en médula ósea (MO) a mediados del siglo pasado, desde entonces este tejido se ha convertido en el estándar de oro para la obtención y caracterización de CTM. Actualmente se sabe que este tipo de células se encuentran alojadas en nichos distribuidos por todo el organismo, donde contribuyen a los procesos de regeneración del tejido donde se localizan. No obstante, encontrar una fuente alterna de CTM con las mismas características que las de MO, pero que su extracción no suponga riesgo para el donador es fundamental para su utilización con fines terapéuticos. En este trabajo se aislaron células troncales de médula ósea, y se compararon con tejido adiposo y gelatina de Wharton y caracterizaron de acuerdo a los criterios de la Sociedad Internacional para la Terapia Celular (ISCT). Los resultados mostraron que la morfología, diferenciación osteogénica y adipogénica, así como la expresión de los antígenos de superficie CD90, CD73 y CD105 cumplen con los estándares, señalando a las provenientes de gelatina de Wharton como mejor opción.

ABSTRACT: Mesenchymal stem cells (MSC) represent a heterogeneous population with the capacity to self-renew and differentiate into different cell types. At the middle of the last century these cells initially were described in bone marrow (BM), thence this tissue has become the gold standard for obtaining and characterization of MSC. It is known that these cells are housed in specific areas called niches distributed throughout all body, where they contribute to tissue regeneration processes of self-tissue were they are located. However, finding an alternative source of CTM with the same characteristics that have showed in MO, but its obtention no represent a risk since the donor is essential to their use for therapeutic purposes. In this study we isolated mesenchymal stem cells from bone marrow, adipose tissue and Wharton's jelly and they were compared in their characteristics in according to the standards of the International Society for Cellular Therapy (ISCT). The results showed that the morphology as well as adipogenic and osteogenic differentiation and also the expression of surface antigens (CD90, CD73, and CD105) from all tissues accomplished the standards, although Wharton's jelly represented the best option.

Efecto de la dehidroepiandroesterona y el acetónido de triamcinolona sobre la línea celular 3T3-L1 / Effect of dehydroepiandroesterone and triamcinolone acetonide on 3T3-L1 cell line

RESUMEN: La piel es el órgano más extenso en el ser humano, su integridad representa protección contra diferentes agentes químicos, biológicos y mecánicos. Las lesiones ocasionadas en este tejido se resuelven mediante la formación de una cicatriz, sin embargo, diferentes alteraciones moleculares pueden sobre estimular este proceso, lo que conlleva a la formación de cicatrices aberrantes (hipertrófica o queloide). El tratamiento más recomendado para este tipo de lesiones es la aplicación intralesional del acetónido de triamcinolona (AT) y por otro lado, la dehidroepiandrosterona (DHEA) es una pro-hormona que posee una gran variedad de efectos biológicos como: regulación de la síntesis de fibras de colágeno, protección celular, propiedades antitumorales, antiinflamatorias y antioxidante. En este trabajo, se estudió la combinación de AT-DHEA sobre la proliferación y muerte celular en la línea celular de fibroblastos 3T3-L1. Los resultados mostraron que la AT a 100 M y la DHEA a 1000 M inhiben la proliferación en un 50 y 40% respectivamente. La combinación de AT-DHEA (10000-10 M) inhibe la proliferación celular e inducen muerte celular programada, entonces esta combinación pudiera utilizarse en cicatrices hipertróficas o queloides para su eliminación.

ABSTRACT: The skin in the human is the largest organ, his integrity represents protection against various chemical, biological and mechanical agents. The injuries in this tissue are solved by forming a scar, however, different molecular alterations may overstimulate this process, leading to the formation of aberrant scars (hypertrophic or keloid). The most recommended treatment for such injuries is the intralesional application of triamcinolone acetonide (TA) and on the other hand, dehydroepiandrosterone (DHEA) is a pro-hormone that has a wide variety of biological effects such as regulation of the synthesis of collagen fibers, cell protection, anti-tumor properties, anti-inflammatory and antioxidant. In this paper, the combination of AT-DHEA on proliferation and cell death in fibroblast cell line 3T3-L1 was studied. The results showed that the AT 100 and 1000 M DHEA to inhibit proliferation by 50 and 40% respectively. The combination of AT-DHEA (10000-10 M) inhibits cell proliferation and induce programmed cell death, so this combination could be used in hypertrophic or keloid scars for disposal.

Cytotoxic activity of Justicia spicigera is inhibited by bcl-2 proto-oncogene and induces apoptosis in a cell cycle dependent fashion.

Identification of organic compounds from plants is of clinical significance because of the effect that they might have in patients with haematopoietic disorders. We studied the effect of the plant extract Justicia spicigera (Acanthaceae) in different haematopoietic cells: human leukaemic cell lines, umbilical cord blood cells, and mouse bone marrow cells. By examining colony formation and performing the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay it was shown that the plant extract of Justicia spicigera contains cytotoxic factors for leukaemic cells and has no proliferative activity on normal haematopoietic progenitor cells. Our results show that this plant extract induces apoptosis in the human leukaemia cell line TF-1, but not in the bcl-2 transfectant cell line TB-1. Similar results were obtained using a haemopoietic cell line 32D and 32DBcl2. The cultures of umbilical cord blood cells and mouse bone marrow that contain granulocyte-macrophage colony-stimulating factor (GM-CSF) do not proliferate or become terminally differentiated in the presence of the infusion of Justicia spicigera. GM-CSF that acts by abrogating programmed cell death is not sufficient to inhibit the apoptotic stimulus in TF-1 and 32D cells. Moreover mouse fibroblasts (3T3) and two cervical carcinoma cell lines CALO and INBL, undergo apoptosis in the presence of different concentrations of an infusion from the plant. Our data show that there is a strong correlation between the cytotoxic effect and cell proliferation. Together, these results indicate that the plant infusion of Justicia spicigera does not contain any haematopoietic activity, induces apoptosis inhibited by bcl-2 and is linked to cell proliferation.

Implication of tyrosine kinase receptor and steel factor in cell density-dependent growth in cervical cancers and leukemias.

Cell-cell interaction is important in the expansion of leukemic cells and of solid tumors. Steel factor (SF) or Kit ligand is produced as a membrane-bound form (mSF) and a soluble form. Because both primary gynecological tumors and primary leukemic cells from patients with acute myeloblastic leukemia (AML) have been shown to coexpress c-Kit and SF, we addressed the question of whether mSF could contribute to cell interaction in these cancers. Investigations on primary cervical carcinomas have been hindered by the fact that the cells do not grow in culture. We report herein the establishment of two cervical carcinoma cell lines, CALO and INBL, that reproduce the pattern of SF/c-Kit expression observed in primary tumor samples. In addition, these cells exhibit marked density-dependent growth much in the same way as AML blasts. Using an antisense strategy with phosphorothioate-modified oligonucleotides that specifically target SF without affecting other surface markers, we provide direct evidence for a role of mSF and c-Kit in cell interaction and cell survival in these gynecological tumor cell lines as well as in primary AML blasts. Finally, our study defines the importance of juxtacrine stimulation, which may be as important, if not more, than autocrine stimulation in cancers.

Steel factor sustains SCL expression and the survival of purified CD34+ bone marrow cells in the absence of detectable cell differentiation.

CD34+ cells express the basic helix-loop-helix transcription factor SCL, which is essential for blood cell formation in vivo. In addition, their survival is critically dependent on hemopoietic growth factors. We therefore compared the effects of Steel factor (SF) and GM-CSF on the survival, proliferation, and differentiation of primary human CD34+ cells, as well as the role of SCL during these processes. GM-CSF suppresses apoptosis in CD34+ cells, which proliferate and differentiate into mature granulocytic and monocytic cells (CD34-CD13+) and loose SCL expression. In contrast, SF suppresses apoptosis without a significant increase in cell numbers, and the cells remain CD34+ and SCL+ with a blast-like morphology. Examination of apoptosis by the terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling (TUNEL) reaction and of the cell cycle status indicated that SF is both a survival factor and a mitogenic factor for CD34+ cells. There was, however, constant cell death in a fraction of the population, which could be rescued by GM-CSF. Co-addition of SF and GM-CSF prevents the downregulation of SCL observed in the presence of GM-CSF by itself, allows for prolonged survival and expansion of CD34+ cells in culture, inhibits monocytic differentiation and impairs granulocytic differentiation. Finally, exposure to an antisense SCL but not a control oligonucleotide decreases SCL protein levels and prevents the suppression of apoptosis by SF without affecting GM-CSF-dependent cell survival. These observations suggest that the hemopoietic transcription factor SCL regulates the survival of CD34+ cells in response to SF.

[Transfection of TF-1 cell line with human bcl-2 proto-oncogene provides short-term survival in absence of GM-CSF without changing the phenotype]. / La transfección de la línea celular TF-1 con el proto-oncogen bcl-2 humano proporciona supervivencia a corto plazo en ausencia de GM-CSF sin cambiar el fenotipo.

UNLABELLED: Apoptosis is a process genetically controlled. The produce of the bcl-2 gene, bcl-2, is an anti apoptotic protein that is linked to the external membrane of the mitochondria. OBJECTIVE: To explore the possibility that bcl-2 transfection could change phenotype, response to mitogenic factor, and cell morphology on the TF-1 parental cell line and the bcl-2 transfectant TB-1 or TF-1neo. METHODS: We look at the expression of CD13, CD34 and c-Kit surface markers by flow cytometry. We have measured cell proliferation in response to GM-CSF and cell survival after GM-CSF withdrawal by the MTT assay on the same cell lines. Apoptosis was evaluated by the apoptotic membrane blebbing set up at different times after serum and survival factor removal or tolerance to cytotoxic compounds from Justicia spicigera. RESULTS: According with our results, ectopic expression of the bcl-2 gene prevented apoptosis without changes in morphology or phenotype in the absence of GM-CSF and serum or the presence of the extract from Justicia spicigera. Consisting with the Bcl-2 function, we found that Bcl-2 did not change response to GM-CSF. Serum deprivation or GM-CSF withdrawal induces cell death at 36 hours in TF-1 and TF-1neo cells, whereas TB-1 cells undergo apoptotic membrane blebbing after 96 hours under the same conditions. CONCLUSIONS: Taken together, our data indicate that Bcl-2 is a short term anti apoptotic protein in TB-1 cell line, that does not affect response to GM-CSF neither CD13, CD34 nor c-Kit antigen expression.

[Stem cell factor (SCF) supports granulocyte progenitor survival in mouse bone marrow cultures]. / El factor de células totipotenciales (stem cell factor; SCF) sostiene la supervivencia de progenitores de granulocitos en cultivos de médula ósea de ratón.

The regulation of cell differentiation and cell death in crucial to the generation of hematopoietic cells both in vitro and in vivo. The biologic role of stem cell factor (SCF) in hematopoietic cell development is not well known. We monitored the survival, proliferation and differentiation of mouse hematopoietic cells in culture in the presence of SCF. Examination of colony formation, MTT and thymidine killing of mouse bone marrow indicated that SCF is mainly a survival factor. Our results show that SCF maintains cells in a "undifferentiated" state. Committed granulocytic and monocytic progenitors (CFU-GM) survive for seven days in the presence of SCF alone, under conditions where no maturing granulocytic monocytic cells could be recovered. On transfer to GM-CSF containing cultures, these cells proliferate and differentiate terminally. Together, our data indicate that SCF induces survival in hematopoietic progenitors. Furthermore, SCF favors the survival of granulocytic progenitors over that of monocytic progenitors. In the absence of later acting factors such as GM-CSF, cells that progress beyond the CFU-GM stage lose c-kit expression and die by default. Hence, lack of cell expansion in the presence of SCF by itself is due to constant cell proliferation and survival, which is counterbalanced by cell death. In contrast, the presence of both SCF and GM-CSF allows for the continuous survival and expansion of hematopoietic progenitor cells in culture, as well as favoring their terminal differentiation along granulocytic and monocytic pathways. Furthermore, GM-CSF induces colonies of macrophages that produce G-CSF and IL-6, two molecules involved in granulopoiesis, and these in turn stimulate granulocyte colony formation. Finally, our data suggest that survival signals by SCF are crucial during the differentiative process of granulocytes, giving strength to deterministic model.

[Biology of hematopoietic stem cells]. / Biología de las células totipotenciales hematopoyéticas.

All the cells comprising the hemopoietic system are derived from a common precursor, the totipotent hemopoietic cell (THC), which, through processes of proliferation and differentiation, gives rise to all the mature cells found in the blood and lympho-hemopoietic organs. In order that the processes of proliferation, survival, apoptosis, and differentiation from THCs to mature cells take place, the participation of proteins denoted collectively as cytokines is required. Their role is to promote and regulate one or several functions (depending on the cell type and stage of development), and to participate in one or several stages of cell development of the THCs. By the use of different tissue culture techniques, it was concluded that other non-hemopoietic cell types have an important role. These cells are those comprising the stroma in the bone marrow: fibroblasts, endothelial cells and adipocytes among others. The contribution of the stroma lies in the production of cytokines, as well as providing sustenance for the THCs. Even when it could seem that cytokines are fundamental factors in the regulation of the main functions of the hemopoietic cells, two models have been proposed to explain the process of hemopoiesis: the deterministic and the stocastic. Both models provide some evidence to support their postulates, however, to this date it is not possible, in view of the data, to decide which of the models is more accurate without incurring controversy. Even though the study of the THCs promotes a great number of questions about the basic mechanisms that regulate them, in several laboratories in the world a new aspect of research: their use in transplants, using THCs as a substitute for whole bone marrow transplant and, still in the initial stages, their use as targets for gene therapy for deficiency diseases or even for therapy against cancer.

[The Steel factor]. / El factor Steel.

Mice bearing mutations at either of two loci, dominant White spotting(W) or Steel(Sl), exhibit development defects in hematopoietic, melanocytic and germ cells. Genetics studies have shown that the SI locus encodes the Steel factor (SF), which is the ligand for the tyrosine kinase receptor c-kit, the product of the W locus. SF is synthesized in membrane-bound form and can be processed to produce a soluble form. Cell-cell interaction is important in the production of normal blood cells in vivo and in vitro and in the cellular expansion of leukemic cells. We discuss here how SF decreases the requirements in cell interaction for blast colony formation in acute myeloblastic leukemia (AML) and the presence of membrane-bound SF possibly contributes to the density-dependent growth of the AML blasts. We explain that SF is mainly a survival factor for hematopoietic cells, of little proliferative effect, which maintains CD34+ hematopoietic cells in an undifferentiated state. These properties would potentially allow the maintenance of hematopoietic cells in culture for the purpose of marrow purging or gene therapy. The activation of the c-kit signal transduction pathway may play a significant role in the development of many types of non-hematological malignancies by disrupting normal cell-cell interactions and allowing the growth of cancer cell populations. In summary, the properties of the SF indicate it has a role for survival signals during the process of normal differentiation, AML proliferation and in the maintenance of many c-kit+ tumors.

Product of the Steel locus can replace leukemic cell interaction.

Mutations in the Steel locus, encoding a growth factor (Steel factor or SF) or c-kit, the gene encoding its receptor, result in severe anemia in the mouse. In the present study, we have addressed the mechanism of synergistic growth activation, at the cellular level, by SF and GM-CSF using the blast cells of acute myeloblastic leukemia (AML blasts). Our data indicate that SF drastically alleviates the requirement in cell interaction for blast colony formation in most of the samples tested. Analysis of cultures performed in the presence of SF and GM-CSF at different cell concentrations, ranging from 1,000 to 20,000 cells, suggested a single limiting element, i.e., the blast clonogenic cell, while 2 or more limiting elements were found in cultures stimulated with GM-CSF alone, suggesting interacting cell populations. The presence of membrane-bound SF was detected by immunofluorescence, suggesting the possibility that secreted or membrane-bound SF may, at least in part, contribute to the density-dependent growth of AML blasts. In all samples tested, SF appears to increase the responsiveness of AML blasts to GM-CSF, as demonstrated by a 3-fold decrease of GM-CSF half efficient concentration on addition of SF to the cultures. Exposure of AML blasts to SF did not affect GM-CSF receptor expression, suggesting that this increase in GM-CSF responsiveness is likely to occur at the postreceptor level. Interestingly, 2 of 15 AML samples surveyed did not respond to SF, and were both of the myelomonocytic or monocytic subtype, classified as M4 and M5, respectively.