ABSTRACT
In the last century, progress in the knowledge of human diseases, their diagnosis and treatment have grown exponentially, due in large part to the introduction and use of laboratory animals. Along with this important progress, the need to provide training and guidance to the scientific community in all aspects related to the proper use of experimental animals has been indispensable. Animal research committees play a primary role in evaluating experimental research protocols, from their feasibility to the rational use of animals, but above all in seeking animal welfare. The Institutional Committee for the Care and Use of Animals (IACUC) has endeavored to share several relevant aspects in conducting research with laboratory animals. Here, we present and discuss the topics that we consider of utmost importance to take in the account during the design of any experimental research protocol, so we invite researchers, technicians, and undergraduate and graduate students to dive into the fascinating subject of proper animal care and use for experimentation. The main intention of these contributions is to sensitize users of laboratory animals for the proper and rational use of them in experimental research, as well as to disseminate the permitted and unpermitted procedures in laboratory animals. In the first part, the significance of experimental research, the main functions of IACUC, and the principle of the three R's (replacement, reduction, and refinement) are addressed.
Subject(s)
Animals , Animal Welfare , Animal Experimentation/ethics , Animal Care Committees , Research Design , Animals, LaboratoryABSTRACT
Abstract Background Expression and activity of the potassium channel ether-à-go-go-1 (EAG1) are strongly related to carcinogenesis and tumor progression, which can be exploited for therapeutic purposes. EAG1 activity may be reduced by preventing its phosphorylation with epidermal growth factor receptor (EGFR) kinase inhibitors and by astemizole, which blocks the channel pore and downregulates its gene expression. Objective We aimed to study the potential cooperative antiproliferative effect of the EGFR inhibitor gefitinib and the EAG1-blocker astemizole, in breast cancer cells. Materials and Methods The cells were characterized by immunocytochemistry. Inhibitory concentrations were determined by non-linear regression analysis using dose-response curves. The nature of the pharmacological effect was evaluated by the combination index equation while cell cycle analysis was studied by flow cytometry. Results Astemizole and gefitinib inhibited cell proliferation in a concentration-dependent manner, with inhibitory concentrations (IC 50) values of 1.72 µM and 0.51 µM, respectively. All combinations resulted in a synergistic antiproliferative effect. The combination of astemizole and gefitinib diminished the percentage of cells in G2/M and S phases, while increased accumulation in G0/G1 of the cell cycle. Conclusions Astemizole and gefitinib synergistically inhibited proliferation in breast cancer cells expressing both EGFR and EAG1. Our results suggest that the combined treatment increased cell death by targeting the oncogenic activity of EAG1.
Subject(s)
Humans , Female , Breast Neoplasms/drug therapy , Astemizole/pharmacology , Gefitinib/pharmacology , Antineoplastic Agents/pharmacology , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Gene Expression Regulation, Neoplastic , Astemizole/administration & dosage , Inhibitory Concentration 50 , Cell Line, Tumor , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/pharmacology , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drug Synergism , Ether-A-Go-Go Potassium Channels/antagonists & inhibitors , Ether-A-Go-Go Potassium Channels/genetics , ErbB Receptors/antagonists & inhibitors , ErbB Receptors/genetics , Gefitinib/administration & dosage , Antineoplastic Agents/administration & dosageABSTRACT
Progesterone is an essential hormone for pregnancy maintenance. This hormone acts by binding to its intracellular receptor or by rapid non-genomic actions to regulate a wide variety of biological functions in the feto-placental unit. Progesterone regulates blastocyst implantation and placental development by inducing immunosupression through type Th2 cytokines secretion. This review summarizes current research about the role of progesterone as critical regulator of expression and secretion of cytokines by T-cell and other placental cells.
La progesterona es una hormona esteroide muy versátil y esencial para el mantenimiento del embarazo. El principal mecanismo de acción de la progesterona es el clásico, vía receptor intracelular, regulando diversas funciones, aspectos celulares y vías moleculares implicadas en el proceso de la implantación. Asimismo existen mecanismos adicionales que no dependen de la interacción del complejo hormona receptor con la maquinaria transcripcional y que son capaces de regular rápidamente cascadas de señalización que determinarán la respuesta de la célula. En particular se ha demostrado que la progesterona ejerce efectos inmunosupresores durante la gestación al favorecer la secreción de citocinas de tipo Th2 por los linfocitos T, evento importante para regular el sistema inmunológico materno y evitar el rechazo de la placenta. El objetivo de esta revisión se centra en analizar la influencia de la progesterona en la interfase materno-fetal sobre la expresión y secreción de citocinas por las células T y no T como es el caso del trofoblasto.
Subject(s)
Animals , Female , Mice , Pregnancy , Pregnancy Maintenance/immunology , Progesterone/physiology , Blastocyst , Cytokines/physiology , Embryo Implantation/immunology , Embryo Implantation/physiology , Gene Expression Regulation , Immune Tolerance , Inflammation , Labor, Obstetric/physiology , Lymphocytes/metabolism , Models, Biological , Maternal-Fetal Exchange/immunology , NF-kappa B/physiology , Placenta/growth & development , Placenta/immunology , Pregnancy Maintenance/physiology , Pregnancy Proteins/physiology , Receptors, Progesterone/physiology , Suppressor Factors, Immunologic , Spleen/metabolismABSTRACT
Prolactin (PRL) Is a 23 κDa protein hormone that is produced and secreted by the pituitary lactotrophs. Although PRL was initially regarded as an exclusive pituitary hormone, many nonpituitary tissues were later found to contain and produce this hormone. The most established extrapituitary sites that produce PRL are the decidua, the immune system, brain and endometrium. In the immune system, PRL acts as a cytokine where it plays an important role in human immune responses, including in autoimmune diseases. Here, we will discuss the regulation of PRL gene expression in human lymphocytes and review the functions of PRL made by the immune cells, including its involvement in autoimmunity.
La prolactina es una hormona que fue considerada durante mucho tiempo de origen exclusivamente hipofisario, y cuya función más importante era la promoción de la lactancia. Sin embargo, la prolactina no sólo se sintetiza en diversos sitios del organismo, sino que también participa en una amplia variedad de procesos biológicos. Dentro de los sitios de síntesis extrahipofisarios de esta hormona se encuentran diversas células del sistema inmunológico. A este nivel, la prolactina actúa afectando desde la proliferación celular hasta el estado inmune del individuo. En esta revisión presentamos algunos aspectos relativos a la prolactina de origen linfocitario tales como su síntesis, su participación en el sistema inmunológico y su relación con estados de autoinmunidad.
Subject(s)
Animals , Female , Humans , Male , Mice , Immune System/physiology , Prolactin/physiology , Autocrine Communication , Autoimmune Diseases/metabolism , Autoimmunity/physiology , Cell Differentiation/physiology , Disease Models, Animal , Gene Expression Regulation , Leukocytes/metabolism , Lupus Erythematosus, Systemic/metabolism , Lymphocytes/metabolism , Mice, Inbred NZB , Paracrine Communication , Pituitary Gland, Anterior/metabolism , Pituitary Gland, Anterior , Prolactin/genetics , Promoter Regions, Genetic/genetics , Receptors, Cytokine/physiology , Receptors, Prolactin/metabolism , Transcription, GeneticABSTRACT
La zona pelúcida (ZP) es una capa de glicoproteínas que rodea al ovocito de los mamíferos. Esta cubierta está formada por tre familias de glicoproteínas denominadas ZP1, ZP2 y ZP3, que difieren en sus propiedades inmunológicas y funcionales debido a modificaciones postraduccionales. Estudios llevados a cabo en el ratón sugieren que la función de estas proteínas se encuentra relacionada con el reconocimiento del espermatozoide por la ZP, confiriéndole muy probablemente la connotación de receptores. Esta observación ha permitido que varios laboratorios hayan iniciado la producción y obtención de las proteínas de la ZP, permitiendo la exploración de su papel en procesos fisiológicos y clínicos, y ha abierto la posibilidad de utilizarlas en el desarrollo de un método inmunológico anticonceptivo. En la actualidad la posibilidad de obtener anticuerpos específicos contra los constituyentes proteínicos de la ZP representa una estrategia novedosa para el control de la fertilidad en el humano.
Subject(s)
Contraception, Immunologic/methods , Oocytes , Zona Pellucida/immunology , Fertility , Sperm-Ovum Interactions/immunologyABSTRACT
La vitamina D cobró importancia desde que se descubrió la naturaleza esteroidea y carácter hormonal de uno de sus metabolitos: el calcitriol. Su participación en el mantenimiento de la homeostasis mineral, así como su capacidad para regular la transcripción génica y fomentar la diferenciación celular, han hecho de su estudio tema de gran interés. Los recientes avances en el estudio de la enzima encargada de convertir la 25-hidroxivitamina D en 1.25-dihidroxivitamina D3 (calcitriol), así como la descripción de su mecanismo de acción, han permitido ampliar el conocimiento de los factores reguladores que controlan el equilibrio del sistema endocrino de la vitamina D, y de las implicaciones del calcitriol en la salud en general y en el embarazo en particular.
Subject(s)
25-Hydroxyvitamin D3 1-alpha-Hydroxylase , Pregnancy , Vitamin D , Calcitriol , Cholecalciferol , Ergocalciferols , PlacentaABSTRACT
In this study, the influence of steroid and thyroid hormones and epidermal growth factor on the productin of SHBG by placenta tissue explants was investigated. Explants of trophoblastic tissue obtained from normal term placentas were cultured for 48 h in serum free culture medium, and then for an additional 24 h period in the presence or absence of various concentrations of either estradiol (0.25 - 5 nM), testoterone (0.5 - 500 nM), triiodothyronine (0.01 - 100 nM) or EGF (2-40 µM), respectively. Human SHBG concentration in culture media was estimated on each day by specific two-site time-resolved fluoroimmunometric assay and the results expressed as pmol/mg tissue protein. Binding characteristics and molecular structure of secreted SHBG were determined by [3H]5a-DHT binding assays and Western blot analysis, espectively. Estradiol and triidothyronine but not testoterone increased significantly (p<0.05 vs. control) the secretion of SHBG into the culture media. Addition of EGF did not significantly change the production of SHBG at the various concentrations studied. [3H]5a-DHT binding assays and Western blot analysis of placental SHBG resulted in identical binding affinities (Kd 2.0 ñ 0.16 x 10-9M= and molecular structure to those obtained in serum from normal pregnant women. These findings support and extend previous observations by our laboratory indicating that SHBG gene is expressed in the placenta and provide further evidence on the hormonal regulatory characteristics of this steroid-binding protein in cultured placenta