RESUMEN
Estrogens up-regulate expression of the estrogen receptor alpha (ER) gene in most mammalian tissues studied. Using the ovariectomized ewe as a model, we determined that estradiol (E(2)) acted post-transcriptionally to increase endometrial ER mRNA concentrations by enhancing the stability of the message. The purpose of this study was to determine whether a similar E(2) effect occurs in Ishikawa cells, a well-differentiated human endometrial adenocarcinoma cell line. The presence and function of ER protein in Ishikawa cells was demonstrated by transactivation of a transfected plasmid (ERE(2)tkCAT) in response to 10(-)(9) M E(2), resulting in a 550% increase in reporter gene RNA. Ishikawa cells also responded to E(2) by up-regulating their ER mRNA concentration an average of 100% between 7 and 24 h of treatment. The effect of E(2) on ER mRNA stability was measured after blocking transcription with actinomycin D to find that the half-life increased from 6 to 10 h in control and E(2)-treated cells respectively. These results are consistent with cell-free studies which showed significant enhancement of the half-life of radiolabeled ER 3' untranslated region (3'UTR) RNA in extracts from E(2)-treated cells versus those from control cells. Thus, Ishikawa cells provide a relevant model system for the study of E(2)-regulated endometrial gene expression.
Asunto(s)
Neoplasias Endometriales/metabolismo , Estradiol/farmacología , ARN Mensajero/metabolismo , Receptores de Estrógenos/genética , Regulación hacia Arriba/efectos de los fármacos , Animales , Northern Blotting , Sistema Libre de Células , Dactinomicina/farmacología , Neoplasias Endometriales/patología , Femenino , Regiones Promotoras Genéticas , Sondas ARN , Ovinos , Transcripción Genética/efectos de los fármacos , Células Tumorales CultivadasRESUMEN
The apparent ability of astroglia to serve as a lead (Pb) sink in the mature brain may result from either their strategic location, between the blood-brain barrier and neurons, or from intrinsic differences between the ability of astroglia and neurons to accumulate this metal. This phenomenon may be dependent on the degree of cell differentiation. In order to address the latter possibility, Pb accumulation was compared among the following cell culture models: (1) mature and immature rat astroglia, (2) undifferentiated SY5Y human neuroblastoma cells and SY5Y cells differentiated with nerve growth factor, (3) immature rat astroglia grown in differently conditioned media, some of which induce partial differentiation, and (4) rat astroglia and SY5Y cells in co-culture. Astroglial cultures, prepared from 1-day-old rat cerebral hemispheres, were exposed to 1 microM Pb after either 14 (immature) or 21 (mature) days in culture. Pb content of the cells was measured by atomic absorption spectroscopy. Immature astroglia took up less Pb when glutathione (GSH) was added to the medium, suggesting that GSH may regulate Pb uptake in these cells. Undifferentiated neuroblastoma cells accumulated more Pb than did the differentiated ones. Astroglia accumulated up to 24 times more Pb than did neuronal cells. This ability was enhanced by exposure to conditioned medium from a neuroblastoma cell line, but not by endothelial cell-conditioned medium, although this medium induced the expression of a glutamate-activated Ca2+ response. Our findings are in agreement with in vivo studies, and thus validate the use of these cell-culture models for future studies on differential mechanisms of Pb uptake.
Asunto(s)
Astrocitos/metabolismo , Diferenciación Celular/fisiología , Plomo/farmacocinética , Neuroblastoma/metabolismo , Neuronas/metabolismo , Factores de Edad , Animales , Animales Recién Nacidos , Encéfalo/metabolismo , Calcio/metabolismo , Canales de Calcio/fisiología , Células Cultivadas , Ácido Glutámico/farmacología , Glutatión/farmacología , Humanos , Factor de Crecimiento Nervioso/farmacología , Ratas , Ratas Sprague-Dawley , Espectrofotometría Atómica , Células Tumorales CultivadasRESUMEN
Two cases of gout with marked ulnar deviation (UD) are reported. Both cases were previously diagnosed rheumatoid arthritis (RA) at referral, but gout was clinically suspected because of atypical features of RA, and subsequently confirmed by demonstration of monosodium urate crystals under the polarized microscope. No definitive evidence of associated RA was present in either case. Although UD in gout is distinctly rare, it is important to recognize this deformity in gout in order to avoid inappropriate therapy. Mechanical factors might have contributed to the hand deformities in both cases.