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Annalisa De Palma
Ruolo
Ricercatore
Organizzazione
Università degli Studi di Bari Aldo Moro
Dipartimento
DIPARTIMENTO DI BIOSCIENZE, BIOTECNOLOGIE E BIOFARMACEUTICA
Area Scientifica
AREA 05 - Scienze biologiche
Settore Scientifico Disciplinare
BIO/10 - Biochimica
Settore ERC 1° livello
Non Disponibile
Settore ERC 2° livello
Non Disponibile
Settore ERC 3° livello
Non Disponibile
The mammalian growth factor erv1-like (GFER) gene encodes a sulfhydryl oxidase enzyme, named Augmenter of Liver Regeneration (ALR). Recently it has been demonstrated that ALR supports cell proliferation acting as an anti-apoptotic factor. This effect is determined by ALR ability to support the anti-apoptotic gene expression and to preserve cellular normoxic conditions. We recently demonstrated that the addition of recombinant ALR (rALR) in the culture medium of H(2)O(2)-treated neuroblastoma cells reduces the lethal effects induced by the hydrogen peroxide. Similar data have been reported in the regenerating liver tissue from partially hepatectomized rats treated with rALR. The purpose of the present study was to evaluate the effect of the GFER inhibition, via the degradation of the complementary mRNA by the specific siRNA, on the behaviour of the apoptosis (apoptotic gene and caspase expression and apoptotic cell number) and of the oxidative stress-induced parameters (reactive oxygen species (ROS), clusterin expression and mitochondrial integrity) in T98G glioma cells. The results revealed a reduction of (i) ALR, (ii) clusterin and (iii) bcl-2 and an increase of (iv) caspase-9, activated caspase-3, ROS, apoptotic cell number and mitochondrial degeneration. These data confirm the anti-apoptotic role of ALR and its anti-oxidative properties, and shed some light on the molecular pathways through which ALR modulates its biological effects
Acetylcholinesterase (AChE) inhibitors still comprise the majority of the marketed drugs for Alzheimer's disease (AD). The structural arrangement of the enzyme, which features a narrow gorge that separates the catalytic and peripheral anionic subsites (CAS and PAS, respectively), inspired the development of bivalent ligands that are able to bind and block the catalytic activity of the CAS as well as the role of the PAS in beta amyloid (Aβ) fibrillogenesis. With the aim of discovering novel AChE dual binders with improved drug-likeness, homo- and heterodimers containing 2H-chromen-2-one building blocks were developed. By exploring diverse linkages of neutral and protonatable amino moieties through aliphatic spacers of different length, a nanomolar bivalent AChE inhibitor was identified (3-[2-(4-[(dimethylamino)methyl]-2-oxo-2H-chromen-7-yloxy)ethoxy]-6,7-dimethoxy-2H-chromen-2-one (6 d), IC50 =59 nm) from originally weakly active fragments. To assess the potential against AD, the disease-related biological properties of 6 d were investigated. It performed mixed-type AChE enzyme kinetics (inhibition constant Ki =68 nm) and inhibited Aβ self-aggregation. Moreover, it displayed an outstanding ability to protect SH-SY5Y cells from Aβ1-42 damage.
Recently a series of chiral N-(phenoxyalkyl)amides have been reported as potent MT1 and MT2 melatonergic ligands. Some of these compounds were selected and tested for their antioxidant properties by measuring their reducing effect against oxidation of 20,70-dichlorodihydrofluorescein (DCFH) in the DCFHdiacetate (DCFH-DA) assay. Among the tested compounds, N-[2-(3-methoxyphenoxy)propyl]butanamide displayed potent antioxidant activity that was stereoselective, the (R)-enantiomer performing as the eutomer. This compound displayed strong cytoprotective activity against H2O2-induced cytotoxicity resulting slightly more active than melatonin, and performed as Ca2+/calmodulin-dependent kinase II (CaMKII) inhibitor, too.
Several members of a new family of non-sugar-type α-glucosidase inhibitors, bearing a phthalimide moiety connected to a variously substituted phenoxy ring by an alkyl chain, were synthesized and their activities were investigated. The efficacy of the inhibition activity appeared to be governed by the chain length of the substrate. Substrates possessing 10 carbons afforded the highest levels of activity, which were one to two orders of magnitude more potent than the known inhibitor 1-deoxynojirimycin (dNM). Furthermore, structure-activity relationship studies indicated a critical role of electron-withdrawing substituents at the phenoxy group for the activity. Derivatives bearing a chlorine atom along with a strong electron-withdrawing group, such as a nitro group, were the most potent of the series.
The first synthesis of m-hydroxymexiletine (MHM) has been accomplished. MHM displayed hNav1.5 sodium channel blocking activity, and tests indicate it to be ∼2-fold more potent than the parent mexiletine and to have more favorable toxicological properties than mexiletine. Thus, MHM and possible related prodrugs might be studied as agents for the treatment of arrhythmias, neuropathic pain, and myotonias in substitution of mexiletine (metabolite switch), which has turned out to be tainted with common toxicity.
Four mexiletine analogues have been tested for their antiarrhythmic, inotropic, and chronotropic effects on isolated guinea pig heart tissues and to assess calcium antagonist activity, in comparison with the parent compound mexiletine. All analogues showed from moderate to high antiarrhythmic activity. In particular, three of them (1b,c,e) were more active and potent than the reference drug, while exhibiting only modest or no negative inotropic and chronotropic effects and vasorelaxant activity, thus showing high selectivity of action. All compounds showed no cytotoxicity and 1b,c,d did not impair motor coordination. All in, these new analogues exhibit an interesting cardiovascular profile and deserve further investigation.
Abstract: Here, the oxoglutarate carrier, already isolated from various sources and described in the literature, has been purified from rat brain and reconstituted in proteoliposomes for an accurate kinetic study. The rate of uptake of labelled oxoglutarate and malate has been measured in various conditions, essentially in double substrate experiments. The data so obtained fit the hypothesis that the carrier operates by a uniport-exchange mechanism and provide significant values for the kinetic constants and the equilibrium constants implied in the process. Their analysis leads to the conclusion that the carrier is maximally efficient in the exchange between external malate and internal oxoglutarate, as required by the malate/aspartate shuttle, which should be the main role of the oxoglutarate carrier in brain mitochondria.
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