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Perrino C.,University of Naples Federico II | Feliciello A.,University of Naples Federico II | Schiattarella G.G.,University of Naples Federico II | Esposito G.,University of Naples Federico II | And 11 more authors.
Cardiovascular Research

AimsThe aim of the present study was to determine the function and the role of the scaffold protein AKAP121, tethering cAMP dependent protein kinase A to the outer wall of mitochondria, in neonatal ventricular myocytes and the heart. Methods and results: Competitive peptides displacing AKAP121 from mitochondria in the tissue and in the cells were used to investigate the role of AKAP121 in mitochondrial function, reactive oxygen species (ROS) generation, and cell survival. Displacement of AKAP121 from mitochondria by synthetic peptides triggers the death program in cardiomyocytes. Under pathological conditions in vivo, in a rat model of cardiac hypertrophy induced by ascending aorta banding, the levels of AKAP121 are significantly down-regulated. Disappearance of AKAP121 is associated with mitochondrial dysfunction, high oxidative stress, and apoptosis. In vivo delocalization of AKAP121 by competitive peptides replicates some of the molecular signatures induced by pressure overload: mitochondrial dysfunction, increased mitochondrial ROS, and apoptosis. Conclusion: These data suggest that AKAP121 regulates the response to stress in cardiomyocytes, and therefore AKAP121 downregulation might represent an important event contributing to the development of cardiac dysfunction. © The Author 2010. Source

Rampello L.,University of Catania | Battaglia G.,Istituto Neurologico Mediterraneo | Malaguarnera G.,University of Catania
Acta Medica Mediterranea

Diabetic neuropathy is a common complication of diabetes, especially in cases of poor control or long duration, which is characterized by its clinical polymorphism whose most common form is distal symmetric polyneuropathy. This brief review outlines the prevailing views on the epidemiology and pathogenesis. Source

Messina S.,University of Cassino and Southern Lazio | Frati L.,Istituto Neurologico Mediterraneo | Porcellini A.,University of Naples Federico II
Oxidative Medicine and Cellular Longevity

Addition of hydrogen peroxide to cultured astrocytes induced a rapid and transient increase in the expression of Ha-Ras and Ki-Ras. Pull-down experiments with the GTP-Ras-binding domain of Raf-1 showed that oxidative stress substantially increased the activation of Ha-Ras, whereas a putative farnesylated activated form of Ki-Ras was only slightly increased. The increase in both Ha-Ras and Ki-Ras was insensitive to the protein synthesis inhibitor, cycloheximide, and was occluded by the proteasomal inhibitor, MG-132. In addition, exposure to hydrogen peroxide reduced the levels of ubiquitinated Ras protein, indicating that oxidative stress leads to a reduced degradation of both isoforms through the ubiquitin/proteasome pathway. Indeed, the late reduction in Ha-Ras and Ki-Ras was due to a recovery of proteasomal degradation because it was sensitive to MG-132. The late reduction of Ha-Ras levels was abrogated by compound PD98059, which inhibits the MAP kinase pathway, whereas the late reduction of Ki-Ras was unaffected by PD98059. We conclude that oxidative stress differentially regulates the expression of Ha-Ras and Ki-Ras in cultured astrocytes, and that activation of the MAP kinase pathway by oxidative stress itself or by additional factors may act as a fail-safe mechanism limiting a sustained expression of the potentially detrimental Ha-Ras. © 2012 Samantha Messina et al. Source

Dallanoce C.,University of Milan | Grazioso G.,University of Milan | Pome D.Y.,University of Milan | Sciaccaluga M.,Istituto Neurologico Mediterraneo | And 5 more authors.
Journal of Computer-Aided Molecular Design

The binding mode of nicotinic agonists has been thoroughly investigated in the last decades. It is now accepted that the charged amino group is bound by a cation-π interaction to a conserved tryptophan residue, and that the aromatic moiety is projected into a hydrophobic pocket deeply located inside the binding cleft. A hydrogen bond donor/acceptor, maybe a water molecule solvating this receptor subsite, contributes to further stabilize the nicotinic ligands. The position of this water molecule has been established by several X-ray structures of the acetylcholine-binding protein. In this study, we computationally analyzed the role of this water molecule as a putative hydrogen bond donor/acceptor moiety in the agonist binding site of the three most relevant heteromeric (α4β2, α3β4) and homomeric (α7) neuronal nicotinic acetylcholine receptor (nAChR) subtypes. Our theoretical investigation made use of epibatidine 1 and deschloroepibatidine 2 as molecular probes, and was then extended to their analogues 3 and 4, which were subsequently synthesized and tested at the three target receptor subtypes. Although the pharmacological data for the new ligands 3 and 4 indicated a reduction of the affinity at the studied nAChRs with respect to reference agonists, a variation of the selectivity profile was clearly evidenced. © 2013 Springer Science+Business Media Dordrecht. Source

Bonaccio M.,Istituto Neurologico Mediterraneo | Di Castelnuovo A.,Istituto Neurologico Mediterraneo | De Curtis A.,Istituto Neurologico Mediterraneo | Costanzo S.,Istituto Neurologico Mediterraneo | And 4 more authors.
British Journal of Nutrition

Nut intake has been associated with reduced inflammatory status and lower risk of CVD and mortality. The aim of this study was to examine the relationship between nut consumption and mortality and the role of inflammation. We conducted a population-based prospective investigation on 19 386 subjects enrolled in the Moli-sani study. Food intake was recorded by the Italian version of the European Project Investigation into Cancer and Nutrition FFQ. C-reactive protein, leucocyte and platelet counts and the neutrophil:lymphocyte ratio were used as biomarkers of low-grade inflammation. Hazard ratios (HR) were calculated using multivariable Cox proportional hazard models. During a median follow-up of 4·3 years, 334 all-cause deaths occurred. As compared with subjects who never ate nuts, rare intake (≤2 times/month) was inversely associated with mortality (multivariable HR=0·68; 95 % CI 0·54, 0·87). At intake ≥8 times/month, a greater protection was observed (HR=0·53; 0·32, 0·90). Nut intake (v. no intake) conveyed a higher protection to individuals poorly adhering to the Mediterranean diet (MD). A significant reduction in cancer deaths (HR=0·64; 95 % CI 0·44, 0·94) was also observed, whereas the impact on CVD deaths was limited to an inverse, but not significant, trend. Biomarkers of low-grade inflammation were reduced in nut consumers but did not account for the association with mortality. In conclusion, nut intake was associated with reduced cancer and total mortality. The protection was stronger in individuals with lower adherence to MD, whereas it was similar in high-risk groups (diabetics, obese, smokers or those with the metabolic syndrome), as compared with low-risk subjects. Inflammation did not explain the observed relationship. © 2015 The Authors. Source

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