Juan Claudio Benech

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The SIRT 1 enzyme is a NAD dependent deacetylase implicated in ageing, cell protection, and energy metabolism in mammalian cells. How the endogenous activity of SIRT 1 is modulated is not known. The enzyme CD38 is a multifunctional enzyme capable of synthesis of the second messenger, cADPR, NAADP, and ADPR. However, the major enzymatic activity of CD38 is(More)
Local protein synthesis within axons has been studied on a limited scale. In the present study, several techniques were used to investigate this synthesis in sciatic nerve, and to show that it increases after damage to the axon. Neurofilament (NF) mRNAs were probed by RT-PCR, Northern blot and in situ hybridization in axons of intact rat sciatic nerve, and(More)
Ribosomes and polyribosomes were detected by immuno-electron microscopy in the giant axon and small axons of the squid using a polyclonal antibody against rat brain ribosomes. The ribosomal fraction used as antigen was purified by ultracentrifugation on a sucrose density gradient and shown to contain ribosomal RNAs and native ribosomes. The polyclonal(More)
Previous data have suggested that the large nerve terminals present in the synaptosomal fraction from squid optic lobe are capable of protein synthesis (Crispino et al., 1993a,b). We have further examined this issue by comparing the translation products of synaptosomal and microsomal polysomes. Both preparations programmed an active process of translation,(More)
The presence of Myosin Va (an actin-based molecular motor) in the peripheral nervous system was examined and its subcellular distribution within the axons of the sciatic nerve was demonstrated via immunocytochemistry. Myosin Va (M-Va) in the nerve was detected by using SDS-PAGE and Western blot techniques with a polyclonal antibody specifically raised(More)
Synaptosomes from the optic lobes of squid (Loligo forbesi) were prepared by homogenization and allowed to settle onto glass coverslips. Synaptosomes were loaded with Ca(2+) sensitive dyes (Fura-2 AM, Calcium Green-1 AM and Calcium Green-5N AM), visualized by light microscopy and Ca(2+) sensitive fluorescence signals recorded and analyzed. With Fura-2,(More)
UNLABELLED Superparamagnetic iron oxide nanoparticles (SPIONS) were synthesized by thermal decomposition of an organometallic precursor at high temperature and coated with a bi-layer composed of oleic acid and methoxy-polyethylene glycol-phospholipid. The formulations were named SPION-PEG350 and SPION-PEG2000. Transmission electron microscopy, X-ray(More)
Immediately after wounding, bovine corneal endothelial cells develop a fast calcium wave that propagates from the wound border to the rest of the monolayer and extinguishes in approximately 5 minutes. One hour after wounding, a late, slow calcium wave (SCW) develops concomitantly to the depolarization of the plasma membrane potential of the border cells.(More)
Previously [Inesi & de Meis (1989) J. Biol. Chem. 264, 5929-5936] it was shown that dimethyl sulphoxide (Me2SO) increases the amount of Ca2+ accumulated by sarcoplasmic-reticulum vesicles. This effect was related to a decrease in the enzyme affinity for ADP from less than 20 microM to 1 mM. In the present work the apparent affinity of the ADP-sensitive(More)
Previous biochemical, autoradiographic, and ultrastructural data have shown that, in the synaptosomal fraction of the squid optic lobe, protein synthesis is largely due to the presynaptic terminals of the retinal photoreceptor neurons (Crispino et al. [1993a] Mol. Cell. Neurosci. 4:366-374; Crispino et al. [1993b] J. Neurochem. 61:1144-1146; Crispino et al.(More)