RESUMEN

Breast cancer (BC) is a malignant disease with a high prevalence worldwide. The main cause of death is not the primary tumor, but instead the spread of tumor cells to distant sites. The aim of the present study was to examine a new method for the detection of cancer cells in aqueous medium using bioimpedance spectroscopy assisted with magnetic nanoparticles (MNP's) exposure to a constant magnetic field. The spectroscopic patterns were identified for three breast cancer cell lines. Each BC cell line represents a different pathologic stage: the early stage (MCF-7), invasive phase (MDA-MB-231) and metastasis (SK-BR-3). For this purpose, bioimpedance measurements were carried out at a certain frequency range with the aid of nanoprobes, consisting of magnetic nanoparticles (MNPs) coupled to a monoclonal antibody. The antibody was specific for the predominant cell surface protein for each cell line, which was identified by using RT-qPCR and flow cytometry. Accordingly, EpCAM corresponds to MCF-7, MUC-1 to MDA-MB-231, and HER-2 to SK-BR-3. Despite their low concentrations, BC cells could be detected by impedance spectroscopy. Hence, this methodology should permit the monitoring of circulating tumor cells (CTC) and therefore help to prevent recurrences and metastatic processes during BC treatment.

Asunto(s)

RESUMEN

INTRODUCTION AND AIMS: Fecal incontinence is a disabling condition with devastating consequences for the patients. Medical and surgical options are not very satisfactory, reason by which regenerative medicine has been considered in this field. In the present research, we analyzed functional and histologic effects after implanting pluripotent stem cells (PSCs) in a murine model with sphincterotomy. MATERIALS AND METHODS: Female Wistar rats were subjected to sphincterotomy and divided into three groups. Group 1 (control group) was treated with 300µL of balanced saline solution and group 2 (late treatment) and group 3 (early treatment) received 50,000 PSCs resuspended in 300µL of balanced saline solution. All animals were evaluated through high-resolution anorectal manometry 24hours before and after sphincterotomy and every month for three months. Finally, the rats were euthanized and histopathologic sections from the anal canal were obtained. RESULTS: All groups showed a decrease in resting anal pressure and squeeze anal pressure 24hours after sphincterotomy. At the third month, higher anal pressures in the groups treated with PSCs were detected. Regarding the histologic effects, the microscopic architecture was restored and there was a significant decrease in the inflammatory response in the groups treated with PSCs. CONCLUSION: PSCs implantation improves anal tone, as well as histologic structure, presenting better regenerative results when implanted as early treatment.

Asunto(s)

RESUMEN

The identification and characterization of diverse cells types and cell differentiation process requires complex techniques as flow cytometry, immunocytochemistry and the exploration of molecular markers; such techniques require infrastructure and qualified personnel. The objective of this study was to analyze the use of Electrical Bioimpedance Spectroscopy (EBIS) measurements as a non-complex alternative technique to identify populations of undifferentiated mouse Pluripotent Stem Cells (mPSCs), Mouse Embryonic Fibroblasts (MEFs) and the differentiation process from preadipocytes (3T3-L1) to mature adipocytes. EBIS measurements were compared in populations of cells which were characterized previously using microscopy. The results indicate that EBIS technique has a potential sensitivity at certain frequency range to discriminate between both evaluated cell populations and some differentiation process. Additional studies with different concentrations to evaluate quantitatively the sensitivity and specificity of the proposed technique are recommended.

Asunto(s)

RESUMEN

Resumen: Dos de los grandes retos en la biología de las Células Madre (CM) y la Medicina Regenerativa, son el control en la diferenciación de estas células y asegurar la pureza de las células diferenciadas, por lo que es necesario contar con técnicas rápidas, eficientes y precisas para la caracterización de CM y su diferenciación a diferentes linajes celulares. El objetivo de este trabajo fue analizar Células Madre Pluripotentes (CMP) y Células Pancreáticas Diferenciadas (CPD) mediante espectroscopía Infrarroja por Transformada de Fourier (FTIR) y Análisis de Componentes Principales (ACP). Para ello se diferenciaron CMP a CPD, caracterizando el proceso de diferenciación a los días 0, 11, 17 y 21 mediante microscopía óptica y espectroscopia vibracional. Los espectros FTIR se analizaron con el método multivariado de ACP, utilizando su segunda derivada en las regiones de proteínas, carbohidratos y ribosas. Los resultados indican que el ACP permite caracterizar y discriminar CMP y CPD en sus diferentes etapas de diferenciación en las regiones espectrales analizadas. Con lo anterior concluimos que el ACP permite caracterizar química y estructuralmente CMP y diferentes etapas de su diferenciación en una forma rápida, precisa y no invasiva.

Abstract: Two of the greatest challenges in Stem Cells (SCs) biology and regenerative medicine, are differentiation control of SCs and ensuring the purity of differentiated cells. In this sense, fast, efficient and accurate techniques for SCs characterization and their differentiation into different cell lineages are needed. The aim of this study was to analyse Pluripotent Stem Cells (PSCs) and Differentiated Pancreatic Cells (DPCs) by Fourier Transform Infrared (FTIR) spectroscopy and Principal Component Analysis (PCA). For this purpose, we differentiated PSCs toward DPCs, characterizing the differentiation process at different stages (0, 11, 17 and 21 days) through light microscopy and vibrational spectroscopy. FTIR spectra were analysed with the multivariate method of PCA, using the second derivatives in the protein, carbohydrate and ribose regions. The results indicate that the PCA allows to characterize and discriminate PSCs and DPCs at different stages of differentiation in the analysed spectral regions. From these results, we concluded that the PCA allows the chemically and structural characterization of PSCs and the different stages of their differentiation in a fast, accurate and non-invasive way.

RESUMEN

Obesity has reached epidemic proportions, the World Health Organization (WHO) estimates that there are more than 1,000 million overweight adults world-wide. Furthermore, obesity is characterized as an overgrowth of white adipose tissue as a result of adipocyte hypertrophy and hyperplasia. Mitochondria is considered the source of energy within the adipocyte, since it contains the molecular machinery, and it is involved in a large number of metabolic pathways, besides the transformation of chemical energy into adenosine triphosphate. Mitochondria shortage and adipocyte dysfunction result in an excessive accumulation of triacylglycerol in the cytoplasm, which determines an imbalance between energy production and energy expenditure. Resveratrol (RSV) is a polyphenol found in different plants and its effects have been associated with mitochondrial biogenesis. An adipogenesis in vitro model (3T3-L1 preadipocytes) was used, and these cells were differentiated into mature adipocytes. Subsequently the effect of RSV on the adipocytes morphology, the lipid content and mitochondrial activity was evaluated using microscopic and flow cytometry techniques. The effect of RSV on differentiated mature adipocytes, was characterized by the decrease in lipid content and the consequently declination of the mitochondrial activity. 3T3-L1 preadipocytes retained the differentiation ability until passage 18. The RSV at doses of 25 and 50 µM for 48 hours in differentiated mature adipocytes promoted the decreased in lipid content probably due to an increase in mitochondrial activity in the early hours of RSV exposure, causing the consequently declination of mitochondrial activity at the end of 48 hours.

La obesidad ha tomado dimensiones epidémicas globales y la Organización Mundial de la Salud estima que hay más de 1,000 millones de adultos con sobrepeso. Así mismo, la obesidad se ha caracterizado como la expansión del tejido adiposo blanco condicionada por la hipertrofia e/o hiperplasia de los adipocitos. La mitocondria es considerada la fuente de energía dentro del adipocito, debido a que contiene la maquinaria molecular que dirige, a través de diversas vías metabólicas, la transformación de la energía química en adenosíntrifosfato. La escasez de mitocondrias así como su disfunción en el adipocito, resulta en una acumulación excesiva de triacilgliceroles en el citoplasma, lo que condiciona un desequilibrio entre producción de energía y gasto energético. El resveratrol (RSV) es un polifenol que se encuentra en diferentes grupos de plantas y sus efectos se han asociado con la inducción de genes para la biogénesis mitocondrial. Se empleó un modelo de adipogénesis (in vitro) materializado por una línea celular de preadipocitos 3T3-L1, mismos que se diferenciaron a adipocitos maduros. Posteriormente se evaluó el efecto del RSV sobre la morfología, contenido lipídico y actividad mitocondrial en los adipocitos maduros diferenciados a través de las técnicas: microscopía invertida, confocal y citometría de flujo. El efecto del RSV sobre los adipocitos maduros diferenciados, se caracterizó por la disminución del contenido lipídico y consecuentemente de la actividad mitocondrial. Los preadipocitos 3T3-L1 conservaron la capacidad de diferenciación hasta el pase 18. Por otra parte, el resveratrol a dosis de 25 y 50 µM durante 48 horas en adipocitos maduros diferenciados, promueve una disminución en el contenido lipídico probablemente debido a un aumento de la actividad mitocondrial en las primeras horas de exposición al tratamiento, provocando la disminución de la actividad mitocondrial al término de 48 horas.

Asunto(s)

RESUMEN

Debido al auge de la medicina regenerativa, las Células Madre (SC) representan una fuente de reemplazo celular para cualquier tejido, decidiendo emprender este trabajo de investigación con el objetivo de diferenciar células madre embrionarias de ratón (mESC) a células pancreáticas tempranas, realizando su caracterización génica y morfológica. Primeramente se cultivaron y arrestaron en su ciclo celular fibroblastos embrionarios de ratón (MEF) con mitomicina, posteriormente se expandieron las mESC y se sometieron a un protocolo de diferenciación de 21 días hacía células pancreáticas tempranas, evaluándose durante la diferenciación su morfología y expresión relativa de los genes sox-17, pdx-1, ins-1 e ins-2, determinando además la producción de las proteínas insulina y glucagón mediante inmunocitoquímica y citometría de flujo. Se obtuvieron cuerpos embrionarios (EBs) a partir de mESC, con características morfológicas diferentes de acuerdo a su diferenciación, los cuales expresaron genes de la línea germinal endodérmica (sox-17 y pdx-1) a los días 0, 11 y 17 de diferenciación, gen inductor del desarrollo embrionario pancreático (pdx-1) al día 11 de diferenciación y, genes de expresión pancreática (ins-1 e ins-2) a los días 17 y 21 de diferenciación. Finalmente se detectó la producción de proteínas insulina y glucagón en los EBs al día 21 de diferenciación. Se logró diferenciar mESC. El análisis morfológico evidenció cúmulos celulares tridimensionales correspondientes a EBs. Con el análisis de los patrones de expresión génica, se distinguieron inicialmente células con características genéticas de endodermo y posteriormente a partir del día 17 células pancreáticas tempranas, las cuales al día 21 de diferenciación expresaron las proteínas insulina y glucagón...

Due to the boom in regenerative medicine, Stem Cells (SC) represent a source of cell replacement to any tissue, we decided to undertake this research with the objective of differentiating mouse embryonic stem cells (mESC) to early pancreatic cells, developing their genetic and morphological characterization. Initially Mouse embryonic fibroblasts (MEF) were grown and arrested in their cell cycle with mitomycin, subsequently mouse embryonic SC (mESC) were expanded and subjected in to a pancreatic cell differentiation protocol of 21 days. During differentiation, morphology and the relative expression of sox-17, pdx-1, Ins-1 and Ins-2 genes were assessed, also the production of insulin and glucagon proteins was determinated by fluorescence microscopy and flow cytometry. Embryoid bodies (EBs) were obtained from mESC, with different morphological characteristics according to their differentiation, which expressed endodermal germ line genes (sox-17 y pdx-1) at days 0, 11 and 17 of differentiation, an inductor gene of embryonic pancreas development (pdx-1) was detected at day 11 of differentiation. Pancreas genes (ins-1 e ins-2) were expressed at day 17 and 21 of differentiation. Finally the production of insulin and glucagon proteins was detected on the EBS at day 21 of differentiation. In conclusion, the mESC differentiation was achieved. The morphological analysis evidenced three-dimensional cell clusters corresponding to EBs. Analysis of the gene expression patterns in the differentiation process, cells initially showed genetic characteristics of endoderm and thereafter from day 17 of differentiation characteristics of early pancreatic cells which by day 21 of differentiation expressed insulin and glucagon proteins...

Asunto(s)