tiziana cocco - Academia.edu (original) (raw)

Papers by tiziana cocco

Journal of Cellular Physiology, Feb 10, 2017

Parkin mutations are a major cause of early‐onset Parkinson's disease (PD). The impairment of... more Parkin mutations are a major cause of early‐onset Parkinson's disease (PD). The impairment of protein quality control system together with defects in mitochondria and autophagy process are consequences of the lack of parkin, which leads to neurodegeneration. Little is known about the role of lipids in these alterations of cell functions. In the present study, parkin‐mutant human skin primary fibroblasts have been considered as cellular model of PD to investigate on possible lipid alterations associated with the lack of parkin protein. Dermal fibroblasts were obtained from two unrelated PD patients with different parkin mutations and their lipid compositions were compared with that of two control fibroblasts. The lipid extracts of fibroblasts have been analyzed by combined matrix‐assisted laser desorption/ionization‐time‐of‐flight mass spectrometry (MALDI‐TOF/MS) and thin‐layer chromatography (TLC). In parallel, we have performed direct MALDI‐TOF/MS lipid analyses of intact fibroblasts by skipping lipid extraction steps. Results show that the proportions of some phospholipids and glycosphingolipids were altered in the lipid profiles of parkin‐mutant fibroblasts. The detected higher level of gangliosides, phosphatidylinositol, and phosphatidylserine could be linked to dysfunction of autophagy and mitochondrial turnover; in addition, the lysophosphatidylcholine increase could represent the marker of neuroinflammatory state, a well‐known component of PD.

Scientific reports, Mar 28, 2024

PubMed, Jan 13, 2016

The effects of low-level laser therapy (LLLT) has been the focus of recent studies as being assum... more The effects of low-level laser therapy (LLLT) has been the focus of recent studies as being assumed responsible for promoting photostimulatory and photobiomodulatory effects in vivo and in vitro, increasing cell metabolism, improving cell regeneration and invoking an anti-inflammatory response. A positive effect of LLLT on the bone proliferation of some cell types has been observed, but little is known about its effect on dental pulp stem cells (DPSCs). Here, we accurately describe the technical procedure to isolate mesenchymal DPSCs, and assay their osteogenic capacity when irradiated with an LLLT source. These preliminary results show that LLLT irradiation influences the in vitro proliferation of DPSCs and increases the expression of essential proteins for bone formation, although it is necessary to carry out further experiments on other cell types and to uniform the methodological designs.

IBRO Reports, Sep 1, 2019

This article has been accepted for publication and undergone full peer review but has not been th... more This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as

Biochemical and Biophysical Research Communications, 2020

Vimentin, a member of cytoskeleton intermediate filaments proteins, plays a critical role in cell... more Vimentin, a member of cytoskeleton intermediate filaments proteins, plays a critical role in cell structure and dynamics. The present proteomic study reveals reduced amount of six different lengths, N-terminal truncated proteolytic products of vimentin, in the primary skin fibroblasts from two unrelated PD patients, as compared to control fibroblasts. The decreased amount of N-terminal truncated forms of vimentin in parkin-mutant fibroblasts, could contribute to impairment of cellular function, potentially contributing to the pathogenesis of Parkinson disease.

ChemPhotoChem, Sep 11, 2020

Journal of Biotechnology, 2014

structs were transfected into A. gambiae Sua 5.1* cells to measure luciferase activity as a surro... more structs were transfected into A. gambiae Sua 5.1* cells to measure luciferase activity as a surrogate promoter activity. The WHO bioassay (used to expose both mosquito strains to 0.75% permethrin) and quantitative PCR were used to ascertain the regulation and transcriptional levels of CYP6M2, respectively. Presence of putative AGAP010295/AhR and AGAP005300/Nrf2 cis-acting elements within A. gambiae CYP6M2 promoters were established in silico. Luciferase reporter gene assays revealed no promoter activity as confirmed by using CYP9M10 promoter from Culex quinquefasciatus with a known promoter activity as control. Results suggest presence of putative AhR and Nrf2 binding sites in A. gambiae CYP6M2 promoter, which may potentially be associated with insecticide resistance. These if established have implications in the control of malaria.

European Journal of Pharmacology, 2011

A study is presented on the effect of the β-adrenoceptor agonist isoproterenol on mitochondrial o... more A study is presented on the effect of the β-adrenoceptor agonist isoproterenol on mitochondrial oxygen metabolism in fibroblast and heart myoblast cultures. Isoproterenol treatment of serum-limited fibroblasts and proliferating myoblasts results in the promotion of mitochondrial complex I activity and decrease of the cellular level of reactive oxygen species. These effects of isoproterenol are associated with cAMP-dependent phosphorylation of complex I subunit(s). Addition of okadaic acid, inhibitor of protein phosphatase(s), reverses the decline of complex I activity in serum-limited fibroblast cultures and activates the complex in proliferating myoblast cultures. The effects of isoproterenol on complex I activity and reactive oxygen species balance can contribute to the therapeutic effect of the drug.

Additional file 2: Model 1. Principal mode analysis of the deposited structure shows that the two... more Additional file 2: Model 1. Principal mode analysis of the deposited structure shows that the two domains of eIF2Îą can rotate relative to one other, exhibiting a twisting motion.

International Journal of Molecular Sciences, Aug 25, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Springer eBooks, 1987

A study is presented on the effects of papain digestion on the activity and the EPR signals arisi... more A study is presented on the effects of papain digestion on the activity and the EPR signals arising from the semiquinone radical (SQc) and the Fe-S center of bovine heart b-c1 complex, these effects are compared with those exerted by the modification of the complex with ethoxyformic anhydride (EFA).

Journal of Bioenergetics and Biomembranes, 2002

A study is presented on the interaction of carvedilol with mitochondria isolated from several rat... more A study is presented on the interaction of carvedilol with mitochondria isolated from several rat organs. It is shown that carvedilol causes a moderate uncoupling effect under non phosphorylating succinate supported respiration of intact mitochondria, as well as a marked inhibition of coupled respiration with NAD-dependent substrates. The inhibitory effect was also found in the bovine heart purified Complex I

Organelles in Eukaryotic Cells, 1989

The second segment of the respiratory chain of mitochondria (b-c1 complex, complex III or ubiquin... more The second segment of the respiratory chain of mitochondria (b-c1 complex, complex III or ubiquinol-cytochrome c reductase, E.C. 1.10.2.2) is an oligomeric integral protein of approx. 240 kDa in a monomeric form, which catalyses the transfer of electrons from ubiquinol or synthetic analogs to ferricytochrome c. The flow of reducing equivalents from dehydrogenase or quinols to cytochrome c, along the b-c1 complex, results in the effective translocation of two protons from the matrix space (Negative phase) to the outer space (Positive phase); two additional protons, deriving from the scalar oxidation of a hydrogen donor, are released in the P phase, thus giving an overall H+/2e− stoicheiometry of 4.

Cytochrome Systems, 1987

The finding that the H+/e- ratio for electron flow in the ubiquinol-cytochrome c reductase is 4 (... more The finding that the H+/e- ratio for electron flow in the ubiquinol-cytochrome c reductase is 4 (1,2) instead of 2 as predicted by the redox loop mechanism (3) led Mitchell to revise his model and to develop the Q-cycle (4). This mechanism, which also offers explanation for the peculiar features of electron transfer in the b-c1 complexes of redox chains, has met with general favour (5–9). At the same time that the Q-cycle was proposed other groups developed indirect models for the protonmotive activity of the b-c1 complex, based on co-operative interaction between the redox reactions at the catalytic centers and proton transfer in proteins (vectorial Bohr mechanism (10,11), b cycle (12); see also (13)). Further refinement and/or revision of these models led to the proposal by Papa et al. (14–17) of the Q-gated proton pump model and of the semiquinone-cycle by Wikstrom and Krab (18).

Journal of Bioenergetics and Biomembranes, 1997

The effect of different anions on the steady-state proton translocation in bovine bc1 complex rec... more The effect of different anions on the steady-state proton translocation in bovine bc1 complex reconstituted in liposomes was studied. The H+/e- ratio for vectorial proton translocation is at the steady state definitely lower than that measured at level flow, (0.3 vs. 1.0). The presence of azide or arachidonate at micro- and submicromolar concentrations, respectively, gave a substantial reactivation of the

Peptides, 2002

The protein IF 1 is a natural inhibitor of the mitochondrial F o F 1-ATPase. Many investigators h... more The protein IF 1 is a natural inhibitor of the mitochondrial F o F 1-ATPase. Many investigators have been prompted to identify the shortest segment of IF 1 , retaining its native activity, for use in biomedical applications. Here, the activity of the synthetic peptides IF 1-(42-58) and IF 1-(22-46) is correlated to their structure and conformational plasticity determined by CD and [ 1 H]-NMR spectroscopy. Among all the IF 1 segments tested, IF 1-(42-58) exerts the most potent, pH and temperature dependent activity on the F o F 1 complex. The results suggest that, due to its flexible structure, it can fold in helical and/or ␤-spiral arrangements that favor the binding to the F o F 1 complex, where the native IF 1 binds. IF 1-(22-46), instead, as it adopts a rigid ␣-helical conformation, it inhibits ATP hydrolysis only in the soluble F 1 moiety.

Journal of Bioenergetics and Biomembranes, 1995

The thermodynamic forces on electrons (AEh) and protons (Ap) across mitochondrial complexes I, II... more The thermodynamic forces on electrons (AEh) and protons (Ap) across mitochondrial complexes I, III and IV were measured in isolated mitochondria respiring on succinate. The force ratio (AEh/Ap) across complex I close to equilibrium was found to be about 2. The equilibrium force ratio across complex I was measured during sulphite oxidation and was again close to 2. These results indicate that the proton/electron stoichiometry of complex I is 2, in conditions of high protonmotive force.