In vitro antiproliferative activity of 3 H-spiro [1-benzofuran-2,1'-cyclohexane] derivatives / Actividad antiproliferativa in vitro de derivados de 3 H-spiro [1-benzofuran-2, 1'-cyclohexano]

The in vitro effect of the resinous exudate of Heliotropium filifolium, of the 3 H-spiro[1-benzofuran-2,1 '-cyclohexane] derivative called filifolinol 1, isolated from the resin and the semi-synthetic compounds filifolinone 2 and filifolinoic acid 3, obtained from filifolinol 1, were evaluated on the proliferation of an immortalized cell line, UCHT1, derived from rat thyroid. We evaluated the effect of these compounds on UCHT1 cell growth parameters by calculating doubling time; and toxicity using the LIVE/DEAD™ in vitro test. The results showed that the resin is not active, while filifolinone 2, filifolinoic acid 3 and filifolinol 1 produced a significant inhibition of cell doubling time, in concentrations equal or greater than 50, 25 and 75 uM, respectively. The LIVE/DEAD test showed no significant toxicity at these concentrations, compared to cultures kept in absence of compounds. These results suggest a possible cytostatic effect of these compounds, and could therefore constitute potential alternatives for antineoplasic therapy.

Se evaluó el efecto in vitro de la resina aislada desde Heliotropium filifolium y del derivado 3 H-spiro[1-benzofuran-2,1'-cyclohexano] llamado filifolinol 1, obtenido desde este exudado resinoso y los compuestos semi-sintéticos filifolinona 2 y ácido filifolinoico 3, obtenidos a partir de filifolinol 1, sobre la proliferación de la línea celular inmortal, UCHT1, derivada de tumor de tiroide de rata. Evaluamos el efecto de estos compuestos en el desarrollo celular de UCHT1 a través de los parámetros tiempo de doblaje y citotoxicidad usando el test LIVE/DEAD™ in vitro. Los resultados mostraron que la resina no presentó actividad y que filifolinona, ácido filifolinoico y filifolinol producen una inhibición significativa del tiempo de doblaje celular, en concentraciones iguales o superiores a 50, 25 y 75 uM, respectivamente. El test LIVE/DEAD no mostró toxicidad significativa en comparación con los cultivos mantenidos en ausencia de compuestos. Estos resultados sugieren un posible efecto citostático de estos compuestos y por lo tanto, constituirían alternativas potenciales para terapia antineoplásica.

Small-molecule aggregation inhibitors reduce excess amyloid in a trisomy 16 mouse cortical cell line

We have previously characterized a number of small molecule organic compounds that prevent the aggregation of the β-amyloid peptide and its neurotoxicity in hippocampal neuronal cultures. We have now evaluated the effects of such compounds on amyloid precursor protein (APP) accumulation in the CTb immortalized cell line derived from the cerebral cortex of a trisomy 16 mouse, an animal model of Down's syndrome. Compared to a non-trisomic cortical cell line (CNh), CTb cells overexpress APP and exhibit slightly elevated resting intracellular Ca2+ levéis ([Ca2+]¡). Here, we show that the compounds 2,4-dinitrophenol, 3-nitrophenol and 4-anisidine decreased intracellular accumulation of APP in CTb cells. Those compounds were non-toxic to the cells, and slightly increased the basal [Ca2+]¡. Results indícate that the compounds tested can be leads for the development of drugs to decrease intracellular vesicular accumulation of APP in trisomic cells.

Establecimiento de la primera línea celular de paratoroides humana / Establishment of first cell line of human parathyroid

Para el manejo de pacientes con hipoparatiroidismo postquirúrgico se ha intentado el transplante de células de paratiroides humanas. Los problemas para este eventual tratamiento han sido mantener cultivos duraderos a largo plazo y mantener cultivos con función endrocina normal. Existe un método de inmortalización celular, descrito por Caviedes y cols. que permite mantener células humanas con la capacidad de proliferar sin perder sus funciones de células diferenciadas. Con este método de inmortalización se logrará establecer una línea celular continua de paratiroides humana con función endrocina normal a largo plazo: esta última definida como la capacidad de respuesta secretoria normal de paratohormona (PTH), frente a distintas concentraciones de calcio extracelular. En este artículo se presenta el procedimiento y sus resultados in vitro.

For the handling of patients with postsurgical hypoparathyroidism, the trasplant of cells of human parathyroid has been tried. The difficulties to establish this type of cultures have been to maintain cultures lasting in the term and to maintain cultures with normal endocrin function. A method of cellular inmortalization, described by Caviedes et al. exists that allow to maintain human parathyroid cells with the capacity to proliferate without losing their differentiated functions. With this method of inmortalization it will be managed in the long term to establish a continuous parathyroid cellular line with normal endocrinal function, defined as the capacity of normal secretion of paratohormona (PTH), as opposed to different extracellular calcium concentrations. We present de procedure and its in vitro results.

Altered calcium currents in cultured sensory neurons of normal and trisomy 16 mouse fetuses, an animal model for human trisomy 21 (Down Syndrome)

Down syndrome is determined by the presence of an extra copy of autosome 21 and is expressed by multiple abnormalities, with mental retardation being the most striking feature. The condition results in altered electrical membrane properties of fetal dorsal root ganglia (DRG) neurons, as in the trisomy 16 fetal mouse, an animal model of the human condition. Cultured trisomic DRG neurons from human and mouse fetuses present faster rates of depolarization and repolarization in the action potential compared to normal controls and a shorter spike duration. Also, trisomy 16 brain and spinal cord tissue exhibit reduced acetylcholine secretion. Therefore, we decided to study Ca2+ currents in cultured DRG neurons from trisomy 16 and age-matched control mice, using the whole-cell patch-clamp technique. Trisomic neurons exhibited a 62 percent reduction in Ca2+ current amplitude and reduced voltage dependence of current activation at -30 and -20 mV levels. Also, trisomic neurons showed slower activation kinetics for Ca2+ currents, with up to 80 percent increase in time constant values. Kinetics of the inactivation phase were similar in both conditions. The results indicate that murine trisomy 16 alter Ca2+ currents, which may contribute to impaired cell function, including neurotransmitter release. These abnormalities also may alter neural development.