RESUMEN
Human mesenchymal stem cells (hMSCs) have gained traction in transplantation therapy due to their immunomodulatory, paracrine, immune-evasive, and multipotent differentiation potential. The inherent heterogeneity of hMSCs poses a challenge for therapeutic treatments and necessitates the identification of robust biomarkers to ensure reproducibility in both in vivo and in vitro experiments. In this study, we utilized dielectrophoresis (DEP), a label-free electrokinetic phenomenon, to investigate the heterogeneity of hMSCs derived from bone marrow (BM) and adipose tissue (AD). The electrical properties of BM-hMSCs were compared to homogeneous mouse fibroblasts (NIH-3T3), human fibroblasts (WS1), and human embryonic kidney cells (HEK-293). The DEP profile of BM-hMSCs differed most from HEK-293 cells. We compared the DEP profiles of BM-hMSCs and AD-hMSCs and found that they have similar membrane capacitances, differing cytoplasm conductivity, and transient slopes. Inducing both populations to differentiate into adipocyte and osteoblast cells revealed that they behave differently in response to differentiation-inducing cytokines. Histology and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analyses of the differentiation-related genes revealed differences in heterogeneity between BM-hMSCs and AD-hMSCs. The differentiation profiles correlate well with the DEP profiles developed and indicate differences in the heterogeneity of BM-hMSCs and AD-hMSCs. Our results demonstrate that using DEP, membrane capacitance, cytoplasm conductivity, and transient slope can uniquely characterize the inherent heterogeneity of hMSCs to guide robust and reproducible stem cell transplantation therapies.
Asunto(s)
Tejido Adiposo , Diferenciación Celular , Células Madre Mesenquimatosas , Humanos , Células Madre Mesenquimatosas/citología , Ratones , Animales , Tejido Adiposo/citología , Electroforesis/métodos , Células de la Médula Ósea/citología , Células HEK293 , Células Cultivadas , Adipocitos/citología , Células 3T3 NIHRESUMEN
Free fatty acids (FFA) cause apoptosis of pancreatic beta-cells and might contribute to beta-cell loss in type 2 diabetes via the induction of endoplasmic reticulum (ER) stress. We studied here the molecular mechanisms implicated in FFA-induced ER stress initiation and apoptosis in INS-1E cells, FACS-purified primary beta-cells and human islets exposed to oleate and/or palmitate. Treatment with saturated and/or unsaturated FFA led to differential ER stress signaling. Palmitate induced more apoptosis and markedly activated the IRE1, PERK and ATF6 pathways, owing to a sustained depletion of ER Ca(2+) stores, whereas the unsaturated FFA oleate led to milder PERK and IRE1 activation and comparable ATF6 signaling. Non-metabolizable methyl-FFA analogs induced neither ER stress nor beta-cell apoptosis. The FFA-induced ER stress response was not modified by high glucose concentrations, suggesting that ER stress in primary beta-cells is primarily lipotoxic, and not glucolipotoxic. Palmitate, but not oleate, activated JNK. JNK inhibitors reduced palmitate-mediated AP-1 activation and apoptosis. Blocking the transcription factor CHOP delayed palmitate-induced beta-cell apoptosis. In conclusion, saturated FFA induce ER stress via ER Ca(2+) depletion. The IRE1 and resulting JNK activation contribute to beta-cell apoptosis. PERK activation by palmitate also contributes to beta-cell apoptosis via CHOP.
Asunto(s)
Retículo Endoplásmico/efectos de los fármacos , Retículo Endoplásmico/patología , Ácidos Grasos no Esterificados/toxicidad , Células Secretoras de Insulina/efectos de los fármacos , Células Secretoras de Insulina/patología , Factor de Transcripción Activador 3/metabolismo , Factor de Transcripción Activador 6/metabolismo , Animales , Apoptosis/efectos de los fármacos , Calcio/metabolismo , Retículo Endoplásmico/enzimología , Ácidos Grasos no Esterificados/metabolismo , Glucosa/toxicidad , Humanos , Células Secretoras de Insulina/enzimología , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Masculino , Proteínas de la Membrana/metabolismo , Ratones , Persona de Mediana Edad , Proteínas Serina-Treonina Quinasas/metabolismo , Ratas , Ratas Wistar , Transducción de Señal/efectos de los fármacos , Factor de Transcripción CHOP/metabolismo , eIF-2 Quinasa/metabolismoRESUMEN
El presente trabajo es un estudio retrospectivo sobre Embarazo Ectópico (EE) en el Hospital Gineco-Obstétrico Isidro Ayora (HGIOA) durante los años 1992 y 1993. Encontramos un total de 93 casos con una prevalencia de 1 por 250 nacidos vivos. las pacientes fueron multigestas en el 93.5 por ciento de casos y la media de la edad materna fue de 27.9 años. La media de la edad gestacional fue 7 semanas. El factor predisponente más importante, el aborto anterior al EE 54,8 por ciento el cuadro clínico fue dominado por dolor hipogástrico, sangrado genital y anexo doloroso con defensa abdominal a la palpación. Para confirmar el diagnóstico se utilizó el ECO pélvico y culdocentesis. El mayor porcentaje de EE se localizan en la ampolla tubárica 62 por ciento. El 89.2 por ciento de pacientes acudieron al servicio de urgencias de este hospital con EE roto, realizandose salpingectomia total en el 80.6 por ciento de los casos.