Search results for " Biochimica"

The nucleosome-remodeling ATPase ISWI is regulated by poly-ADP-ribosylation.

2008

ATP-dependent nucleosome-remodeling enzymes and covalent modifiers of chromatin set the functional state of chromatin. However, how these enzymatic activities are coordinated in the nucleus is largely unknown. We found that the evolutionary conserved nucleosome-remodeling ATPase ISWI and the poly-ADP-ribose polymerase PARP genetically interact. We present evidence showing that ISWI is target of poly-ADP-ribosylation. Poly-ADP-ribosylation counteracts ISWI function in vitro and in vivo. Our work suggests that ISWI is a physiological target of PARP and that poly-ADP-ribosylation can be a new, important post-translational modification regulating the activity of ATP-dependent nucleosome remodel…

3D cultures of rat astrocytes and brain capillary endothelial cells on Poly-L-lactic acid scaffolds

2016

Tissue engineering is an emerging multidisciplinary field that aims at reproducing in vitro and/or in vivo tissues with morphological and functional features similar to the biological tissue of the human body. In this communication we report setting of three-dimensional structures able to mimic the extracellular matrix of the nervous system: we prepared Poly-L-Lactic Acid (PLLA) porous scaffolds via thermally induced phase separation (TIPS), and investigated the parameters that influence porosity, average pore size and degree of interconnection, i.e. polymer concentration, temperature and time of process. Astrocytes and brain capillary endothelial cells (BCECs) were cultured on these three-…

Interactions between polyamines, acetylpolyamines and PCAF during histone acetylation.

2009

Polyamines are involved in several gene regulatory functions, as the transcription process. In order to clarify their effect, in an initial “in vitro” biochemical study, we considered their influence on the nuclear PCAF acetyltransferase (PCAF-HAT). In a model system, using both commercial histones and laboratory histone preparations from mammary epithelial cells, we evidenced the inhibitory effect played by 40-180 uM spermidine (Spd) versus PCAF, assayed on 250 nM histone and 40 uM acetyl-CoA. At the same concentrations N8-acetylspermidine (N8-Ac.Spd), the acetylated form of spermidine located in the nucleus, exerts a significant activating effect on the PCAF-HAT. In addition, N8-Ac.Spd se…

Pattern of polyamines and related monoacetyl-derivatives in chick embryo retina during development

1994

The pattern of polyamine and GABA in chicken embryo retina photoreceptor membranes

1997

The acetylation of spermidine catalyzed by P/CAF regulates its acetyltransferase activity versus histones

2010

Transcriptional regulation in eukaryotes occurs within a chromatin setting and is strongly inhibited by nucleosomal barriers imposed by histone proteins. Among the well-known covalent modifications of chromatin, the reversible acetylation of specific lysine residues of histones, catalyzed by several acetyltransferase and deacetylases, has been linked to many biological processes including transcriptional regulation. Indeed, many transcriptional coactivators possess histone acetyltransferase (HAT) activity (1). Functional interactions between HAT and polyamines have been previously reported. In particular, it has been shown that polyamines facilitate oligomerization of nucleosomal arrays in …

Micellar electrokinetic capillary chromatography of polyamines and monoacetylpolyamines.

2001

A selective procedure for qualitative and quantitative analysis of ten polyamines by micellar electrokinetic chromatography (MEKC) was developed. Benzoylated polyamines and acetylpolyamines in micellar phase of SDS (10 mM) were separated at 258C by 20 mM borate buffer pH 8.5, containing 8% ethanol, with an applied voltage of 25 kV (5 mA) and then detected at 198 nm. The experimental factors and operational parameters were optimized by performing analysis at different surfactant concentrations, pH, voltage and temperature with and without ethanol. The repeatibility of migration times and peak heights is a peculiarity of the method here described.

Does a specific genetic background influence endurance or power-orientated phenotypes?

2012

The purpose of this study was to determine the probability of individuals having the “best” mitochondrial biogenesis related polygenic profile that could increase performance. We compared polygenic profile analyzing several polymorphisms on sixty professional italian soccer players, considered “power-oriented athletes” and thirty sedentary volunteers. Samples of venous blood were obtained by standard clinical procedures and anticoagulant-treated blood was used to prepare genomic DNA. The polymorphic sites were scanned using PCR-RFLP protocols with different enzyme. Furthermore, a cloted part of venus blood sample was used to obtain serum from which we analyzed total cholesterol, high densit…

Polymerase Chain Reaction (PCR)

2008

Anti-proliferative effect of main dietary phytosterols and β-cryptoxanthin alone or combined in human colon cancer Caco-2 cells through cytosolic Ca+…

2015

β-cryptoxanthin (β-Cx) and phytosterols (Ps) have potential against different cancer types, including colon cancer. However, their combined action has not been reported so far. Human colon cancer Caco-2 cells were treated 24 h with β-Cx and/or main dietary Ps (β-sitosterol, campesterol and stigmasterol), alone or in combination, at concentrations compatible with physiological human serum levels. A decrease in cell viability due to apoptosis (rise in sub-G1 population and exposure of membrane phosphatidylserine) was accompanied with dephosphorylation of BAD, mitochondrial depolarization and caspase 3-dependent PARP cleavage, with intracellular Ca2+ influx and increase of RONS levels as initi…