Estudios sobre el metabolismo lipídico en células de hepatocarcinoma humano HepG2 y su relación con el reloj molecular

El sistema circadiano comprende osciladores presentes en órganos, tejidos e incluso en células individuales, y es el encargado de regular la fisiología de los organismos de manera temporal. El hígado presenta un reloj endógeno que funciona en estrecho vínculo con el metabolismo, y aunque se conoce que es ampliamente influenciado por los horarios de las comidas poco se conoce sobre su funcionamiento a nivel molecular y más aún en condiciones de proliferación exacerbada como es el caso de las células cancerosas. A su vez tampoco se conoce en profundidad el rol que cumple el reloj biológico en el metabolismo lipídico ni la forma en la que se interconectan entre si.Fil: Monjes, Natalia M.. Consejo Nacional de Investigaciones Científicas y Técnicas.Fil: Guido, Mario E.. Consejo Nacional de Investigaciones Científicas y Técnicas

Expression of Novel Opsins and Intrinsic Light Responses in the Mammalian Retinal Ganglion Cell Line RGC-5. Presence of OPN5 in the Rat Retina

The vertebrate retina is known to contain three classes of photoreceptor cells: cones and rods responsible for vision, and intrinsically photoresponsive retinal ganglion cells (RGCs) involved in diverse non-visual functions such as photic entrainment of daily rhythms and pupillary light responses. In this paper we investigated the potential intrinsic photoresponsiveness of the rat RGC line, RGC-5, by testing for the presence of visual and non-visual opsins and assessing expression of the immediate-early gene protein c-Fos and changes in intracellular Ca2+mobilization in response to brief light pulses. Cultured RGC-5 cells express a number of photopigment mRNAs such as retinal G protein coupled receptor (RGR), encephalopsin/panopsin (Opn3), neuropsin (Opn5) and cone opsin (Opn1mw) but not melanopsin (Opn4) or rhodopsin. Opn5 immunoreactivity was observed in RGC-5 cells and in the inner retina of rat, mainly localized in the ganglion cell layer (GCL). Furthermore, white light pulses of different intensities and durations elicited changes both in intracellular Ca2+ levels and in the induction of c-Fos protein in RGC-5 cell cultures. The results demonstrate that RGC-5 cells expressing diverse putative functional photopigments display intrinsic photosensitivity which accounts for the photic induction of c-Fos protein and changes in intracellular Ca2+ mobilization. The presence of Opn5 in the GCL of the rat retina suggests the existence of a novel type of photoreceptor cell

Fin systems comparative anatomy in model Batoidea Raja asterias and Torpedo marmorata: Insights and relatioships between musculo-skeletal layout, locomotion and morphology

The macroscopic and microscopic morphology of the appendicular skeleton was studied in the two species Raja asterias (order Rajiformes) and Torpedo marmorata (Order Torpediniformes), comparing the organization and structural layout of pectoral, pelvic, and tail fin systems. The shape, surface area and portance of the T. marmorata pectoral fin system (hydrodynamic lift) were conditioned by the presence of the two electric organs in the disk central part, which reduced the pectoral fin surface area, suggesting a lower efficiency of the "flapping effectors" than those of R. asterias. Otherwise, radials' rays alignment, morphology and calcification pattern showed in both species the same structural layout characterized in the fin medial zone by stiffly paired columns of calcified tiles in the perpendicular plane to the flat batoid body, then revolving and in the horizontal plane to continue as separate mono-columnar rays in the fin lateral zone with a morphology suggesting fin stiffness variance between medial/lateral zone. Pelvic fins morphology was alike in the two species, however with different calcified tiles patterns of the 1st compound radial and pterygia in respect to the fin-rays articulating perpendicularly to the latter, whose tile rows lay-out was also different from that of the pectoral fins radials. The T. marmorata tail-caudal fin showed a muscular and connective scaffold capable of a significant oscillatory forward thrust. On the contrary, the R. asterias dorsal tail fins were stiffened by a scaffold of radials-like calcified segments. Histomorphology, heat-deproteination technique and morphometry provided new data on the wing-fins structural layout which can be correlated to the mechanics of the Batoid swimming behavior and suggested a cartilage-calcification process combining interstitial cartilage growth (as that of all vertebrates anlagen) and a mineral deposition with accretion of individual centers (the tiles). The resulting layout showed scattered zones of un-mineralized matrix within the calcified mass and a less compact texture of the matrix calcified fibers suggesting a possible way of fluid diffusion throughout the mineralized tissue. These observations could explain the survival of the embedded chondrocytes in absence of a canalicular system as that of the cortical bone

A Family of Unitary Higher Order Equations

A scalar field obeying a Lorentz invariant higher order wave equation, is minimally coupled to the electromagnetic field. The propagator and vertex factors for the Feynman diagrams, are determined. As an example we write down the matrix element for the Compton effect. This matrix element is algebraically reduced to the usual one for a charged Klein–Gordon particle. It is proven that the nth order theory is equivalent to n independent second order theories. It is also shown that the higher order theory is both renormalizable and unitary for arbitrary n.Facultad de Ciencias Exacta

A metabolic oscillator controls temporal changes in lipid metabolism and redox Istatus in tumor cells : implications in chemotherapy suceptibility

Biological clocks even present in immortalized cell lines, regulate physiological processes in a time-dependent manner, driving transcriptional and metabolic rhythms. The disruption of circadian rhythmicity in modern life (shiftwork, jetlag, etc.) may promote higher cancer risk and metabolic disorders.Fil: Wagner, Paula M.. Consejo Nacional de Investigaciones Científicas y TécnicasFil: Monjes, Natalia M.. Consejo Nacional de Investigaciones Científicas y TécnicasFil: Guido, Mario E.. Consejo Nacional de Investigaciones Científicas y Técnica

Identification and characterization of key circadian clock genes of tobacco hairy roots : putative regulatory role in xenobiotic metabolism

This work was also supported by research grants to P.M. from the Spanish Ministry of Economy and Competitiveness, from the Generalitat de Catalunya (AGAUR), from the Global Research Network of the National Research Foundation of Korea, from the European Commission Marie Curie Research Training Network (ChIP-ET) and from the Spanish Ministry of Economy and Competitiveness, through the "Severo Ochoa Programme for Centres of Excellence in R&D" 2016-2019 (SEV-2015-0533)".The circadian clock is an endogenous system that allows organisms to daily adapt and optimize their physiology and metabolism. We studied the key circadian clock gene (CCG) orthologs in Nicotiana tabacum seedlings and in hairy root cultures (HRC). Putative genes involved in the metabolism of xenobiotic compounds (MXC) were selected and their expression profiles were also analyzed. Seedlings and HRC displayed similar diurnal variations in the expression profiles for the CCG examined under control conditions (CC). MXC-related genes also showed daily fluctuations with specific peaks of expression. However, when HRC were under phenol treatment (PT), the expression patterns of the clock and MXC-related genes were significantly affected. In 2-week-old HRC, PT downregulated the expression of NtLHY, NtTOC1, and NtPRR9 while NtFKF1 and NtGI genes were upregulated by phenol. In 3-week-old HRC, PT also downregulated the expression of all CCG analyzed and NtTOC1 was the most affected. Following PT, the expression of the MXC-related genes was upregulated or displayed an anti-phasic expression profile compared to the expression under CC. Our studies thus provide a glimpse of the circadian expression of clock genes in tobacco and the use of HRC as a convenient system to study plant responses to xenobiotic stresses