Il trasferimento di molecole tra cellule cerebrali è mediato anche da vescicole extracellulari

RNA-binding proteins expressed in differentiating rat astrocytes

Replication-independent expression of H1˚ and H3.3 histone variants is probably regulated by different RNA-binding proteins

DNA in eukaryotes is wrapped around core histones to form nucleosomes, the basic units of chromatin. The linker histones H1 bind DNA where it enters and leaves the nucleosome, thus stabilizing higher order structures. Chromatin is a dynamic complex, modulated by different processes such as DNA-methylation, post-translational modifications of histones, and incorporation of specific histone variants. Throughout rat brain development, expression of H1° and H3.3 histone variants is mainly regulated at the post-transcriptional level. These proteins are of interest for their possible involvement in the replication-independent chromatin remodelling induced by extracellular stimuli. We previously c…

Sustained release of silibinin to the posterior segment of the eye by mucoadhesive NLC

Oligodendroglioma cells shed microvesicles which contain TRAIL as well as molecular chaperones and induce cell death in astrocytes.

Microvesicles (MVs) shed from G26/24 oligodendroglioma cells were previously reported to cause a reproducible, dose-dependent, inhibitory effect on neurite outgrowth, and eventually neuronal apoptosis, when added to primary cultures of rat cortical neurons. These effects were reduced but not abolished by functional monoclonal antibodies against Fas-L. In order to investigate whether MVs contain other factors able to induce cell death, we tested them for TRAIL and found clear evidence of its presence in the vesicles. This finding suggests the possibility that Fas-L and TRAIL cooperate in inducing brain cell death. Aimed at understanding the route through which the vesicles deliver their mess…

PPARa GENE VARIATION AND PHISYCAL PERFORMANCE IN ITALIAN SOCCER PLAYERS

PURPOSE: One of the genes of the health-related fitness phenotype is a PPARα coding for peroxisome proliferator activator receptor alpha, a central regulator of expression of genes involved in fatty acid metabolism. The aim of our research was to study the role of polymorphism of PPARα gene in performance enhancing in Italian soccer players. METHODS: Sixty professional soccer players and thirty sedentary volunteers were enrolled in the study. Samples of venous blood were obtained at rest in the morning by conventional clinical procedures. Serum was collected and lipid profile was measured by using a commercial kit. An aliquote of anticoagulant-treated blood was used to prepare genomic DNA f…

Oligodendroglioma cells synthesize the differentiation-specific linker histone H1˚ and release it into the extracellular environment through shed vesicles

Chromatin remodelling can be involved in some of the epigenetic modifications found in tumor cells. One of the mechanisms at the basis of chromatin dynamics is likely to be synthesis and incorporation of replacement histone variants, such as the H1° linker histone. Regulation of the expression of this protein can thus be critical in tumorigenesis. In developing brain, H1° expression is mainly regulated at the post-transcriptional level and RNA-binding proteins (RBPs) are involved. In the past, attention mainly focused on the whole brain or isolated neurons and little information is available on H1° expression in other brain cells. Even less is known relating to tumor glial cells. In this st…

Rat PIPPin is probably part of a large complex of RNA-binding proteins

Throughout rat brain development, expression of histones variants is mainly regulated at the post-transcriptional level. We previously cloned two cDNAs encoding, respectively, PIPPin (or CSD-C2), a brain-enriched protein able to bind the 3’end of H1° and H3.3 mRNAs, and LPI (longer isoform of PEP-19). Both PEP-19 and LPI are brain-specific. By western blot, we found that PIPPin expression in PC12 cells is enhanced by NGF-induced differentiation. We investigated the RNA-binding properties of the three proteins using their 6 histidine-tagged recombinant fusions and found that they all bind H1° and H3.3 RNAs. Since PEP-19 and LPI are camstatins, we also analyzed whether calmodulin could interf…

Identification of nuclear proteins which interact with H1° mRNA.

In developing rat brain the synthesis of H1° histone is mainly regulated at posttranscriptional level and probably depends on RNA-binding proteins (RBPs) (1). We previously identified RBPs apparently specific for this messenger (2) and cloned two novel proteins by screening an expression cDNA library by binding to radiolabeled RNA (3-10). Here we report the use of biotinylated H1° RNA as bait to isolate by chromatography nuclear proteins which interact with H1° mRNA. We identified by mass spectrometry abundant RBPs and molecular chaperones. By western blot we also evidenced, among the RNA-bound proteins, the cold shock domain-containing protein 2 (CSD-C2, also know as PIPPin), a brain-enric…

ROLE OF RNA BINDING PROTEIN IN THE NERVE CELL DIFFERENTIATION

Synthesis of H1˚ and H3.3 histone proteins, in the developing rat brain, seems to be regulated mainly at the post-transcriptional level. Since regulation of RNA metabolism depends on a series of RNA-binding proteins (RBPs), we have been searching for RBPs involved in the post-transcriptional regulation of the H1˚ and H3.3 genes. Previously, we reported isolation, from a cDNA expression library, of an insert encoding a novel protein, the C-terminal half of which is identical to that of PEP-19, a brain-specific protein involved in calcium metabolism. The novel protein was called long PEP-19 isoform (LPI). We showed that LPI, as well as PEP-19, can bind H1˚ RNA. Since PEP19 and LPI contain a c…

Monitoring biomarkers during preseason preparation period in professional soccer players

Aim. The present study aimed at investigating the effect of a 3-week experimental intervention on biomarkers in professional soccer players during the preseason preparation-period. Methods. Eight participants (age 22.5±2.2 yrs) were enrolled in the study. During the physical preparation period players have attended a training program (51,9 hours) planned by coaches of “Equipe-Sicilia-2009”. Results. At rest, the lipid profile, the creatine kinase (CK), the lactic-acid dehydrogenase (LDH) and the expression of nuclear receptors peroxisome-proliferator-activated receptors (PPAR α/γ) were analyzed before starting and after 3 weeks of training sessions. The plasma level of CK in our samples sho…

Histone H1° and H3.3 RNA-binding proteins identified in the developing rat brain

Histone H1° RNA-binding proteins in developing rat brain.

Co-culture of rat brain cells as a tool for studying cell-cell interactions

Brain capillary endothelial cells (BCECs) form the blood-brain barrier (BBB) in response to interaction with other brain cells (astrocytes, pericytes and neurons). BCECs are characterized by tight junctions (TJ), maturation and stabilization of which require different proteins, such as occludin. When co-cultured with astrocytes and neurons, BCECs were found to form a monolayer resembling the natural BBB: paracellular flux of dopamine and sucrose (i.e. compounds which are unable to cross the BBB in vivo) significantly decreased (1), while the transendothelial electrical resistance (TEER) increased. In these conditions, BCECs produced a larger amount of occludin and tended to localize it at t…

Extracellular membrane vesicles can mediate intercellular transfer of molecules

Many eukaryotic cell types, including neural cells, release into the extracellular environment vesicles of different sizes and composition. Neurons and astrocytes shed extracellular vesicles which contain FGF2 and VEGF and could be involved in interaction with endothelial cells, to form the blood-brain barrier. Also brain tumor cells, such as glioblastomas, release vesicles in the extracellular space. Microvesicles (MVs) shed from G26/24 oligodendro¬glioma cells were previously reported to contain FAS-L and to cause a reproducible, dose-dependent, inhibitory effect on neurite outgrowth, and neuronal apoptosis, when added to primary cultures of rat cortical neurons. More recently, they were …

Extracellulare membrane vesicles as vehicles for cell-to-cell and cell-to-extracellular matrix functional interactions

L`ANGIOGENESI NEL SISTEMA NERVOSO ANGIOGENESIS IN THE NERVOUS SYSTEM

PPAR alpha gene variants as predicted performance-enhancing polymorphisms in professional Italian soccer players

Patrizia Proia,1 Antonino Bianco,1 Gabriella Schiera,2 Patrizia Saladino,2 Valentina Contrò,1 Giovanni Caramazza,3 Marcello Traina,1 Keith A Grimaldi,4 Antonio Palma,1 Antonio Paoli5 1Sport and Exercise Sciences Research Unit, 2Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Palermo, Italy; 3Regional Sports School of CONI Sicilia, Sicily, Italy; 4Biomedical Engineering Laboratory, Institute of Communication and Computer Systems, National Technical University of Athens, Athens, Greece; 5Department of Biomedical Sciences, University of Padova, Padua, Italy Background: The PPARα gene encodes the peroxisome proliferato…

Identification in the rat brain of a set of nuclear proteins interacting with H1° mRNA

Synthesis of H1° histone, in the developing rat brain, is also regulated at post-transcriptional level. Regulation of RNA metabolism depends on a series of RNA-binding proteins (RBPs); therefore, we searched for H1° mRNA-interacting proteins. With this aim, we used in vitro transcribed, biotinylated H1° RNA as bait to isolate, by a chromatographic approach, proteins which interact with this mRNA, in the nuclei of brain cells. Abundant RBPs, such as heterogeneous nuclear ribonucleoprotein (hnRNP) K and hnRNP A1, and molecular chaperones (heat shock cognate 70, Hsc70) were identified by mass spectrometry. Western blot analysis also revealed the presence of cold shock domain-containing protein…

PPARα GENE VARIANTS AS PREDICTED PERFORMANCE ENHANCING POLYMORPHISMS IN PROFESSIONAL ITALIAN SOCCER PLAYERS

RNA-binding activity of the rat calmodulin-binding PEP-19 protein and of the long PEP-19 isoform

Synthesis of H1˚ histone protein, in the developing rat brain, seems to be regulated mainly at the post-transcriptional level. Since regulation of RNA metabolism depends on a series of RNA-binding proteins, we have been searching for RNA-binding proteins involved in the post-transcriptional regulation of the H1˚ gene. We recently reported isolation, from a cDNA expression library, of an insert encoding a novel protein, the C-terminal half of which is identical to that of PEP-19, a brain-specific protein involved in calcium metabolism. The novel protein was called long PEP-19 isoform (LPI). Herein we show that LPI, as well as PEP-19, can bind H1˚ RNA. Moreover, in order to improve production…

Role of RNA-binding proteins in the replication-independent expression of H1° and H3.3 histone variants