Early phase of plasticity-related gene regulation and SRF dependent transcription in the hippocampus

Hippocampal organotypic cultures are a highly reliable in vitro model for studying neuroplasticity: in this paper, we analyze the early phase of the transcriptional response induced by a 20 \ub5M gabazine treatment (GabT), a GABA-Ar antagonist, by using Affymetrix oligonucleotide microarray, RT-PCR based time-course and chromatin-immuno-precipitation. The transcriptome profiling revealed that the pool of genes up-regulated by GabT, besides being strongly related to the regulation of growth and synaptic transmission, is also endowed with neuro-protective and pro-survival properties. By using RT-PCR, we quantified a time-course of the transient expression for 33 of the highest up-regulated genes, with an average sampling rate of 10 minutes and covering the time interval [10 3690] minutes. The cluster analysis of the time-course disclosed the existence of three different dynamical patterns, one of which proved, in a statistical analysis based on results from previous works, to be significantly related with SRF-dependent regulation (p-value<0.05). The chromatin immunoprecipitation (chip) assay confirmed the rich presence of working CArG boxes in the genes belonging to the latter dynamical pattern and therefore validated the statistical analysis. Furthermore, an in silico analysis of the promoters revealed the presence of additional conserved CArG boxes upstream of the genes Nr4a1 and Rgs2. The chip assay confirmed a significant SRF signal in the Nr4a1 CArG box but not in the Rgs2 CArG box

COMPARATIVE STUDIES REGARDING HEAVY ELEMENTS CONCENTRATION IN HUMAN CORTICAL BONE

The heavy metal metabolism in the human hard tissues biostructures can be assessed by individual studies made on targeted groups from the same living area. During lifetime the exposure to the heavy metals due to environment and professional sources leads to their concentration increment at calcified tissues level, their study reflecting thaw the integrated or cumulative exposure. This study is conducted on 16 samples from human hard tissue in order to assess the metallic elemental concentration in bone and to find the influence of the human subject age on the results. Due to the fact that previous studies showed high differences in bones metals concentrations relative to the sex, living area and bone type we used in this study only male human bones, from the same area (Bucharest) and the same bone type (cortical). We supposed that this selection would allow us to assess the average value of the bone metal concentration function of age factor and similar with the natural concentration. Scanning electron microscopy coupled with energy dispersion spectrometry method was chosen to assess the morphology of the studied bones and Ca/P ratio. X-ray fluorescence spectrometric method is proposed for the heavy elements analysis and its accuracy is proved using atomic absorption spectrometry, a well known precise method