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Cystic fibrosis (CF) is a hereditary disease, with 70% of patients developing a proteinopathy related to the deletion of phenylalanine 508. CF is associated with multiple organ dysfunction, chronic inflammation, and recurrent lung... more
Cystic fibrosis (CF) is a hereditary disease, with 70% of patients developing a proteinopathy related to the deletion of phenylalanine 508. CF is associated with multiple organ dysfunction, chronic inflammation, and recurrent lung infections. CF is characterized by defective autophagy, lipid metabolism, and immune response. Intracellular lipid accumulation favors microbial infection, and autophagy deficiency impairs internalized pathogen clearance. Myriocin, an inhibitor of sphingolipid synthesis, significantly reduces inflammation, promotes microbial clearance in the lungs, and induces autophagy and lipid oxidation. RNA-seq was performed in Aspergillusfumigatus-infected and myriocin-treated CF patients’ derived monocytes and in a CF bronchial epithelial cell line. Fungal clearance was also evaluated in CF monocytes. Myriocin enhanced CF patients’ monocytes killing of A. fumigatus. CF patients’ monocytes and cell line responded to infection with a profound transcriptional change; my...
Glyoxalase 2 is a mitochondrial and cytoplasmic protein belonging to the metallo-β-lactamase family encoded by the hydroxyacylglutathione hydrolase (HAGH) gene. This enzyme is the second enzyme of the glyoxalase system that is responsible... more
Glyoxalase 2 is a mitochondrial and cytoplasmic protein belonging to the metallo-β-lactamase family encoded by the hydroxyacylglutathione hydrolase (HAGH) gene. This enzyme is the second enzyme of the glyoxalase system that is responsible for detoxification of the α-ketothaldehyde methylglyoxal in cells. The two enzymes glyoxalase 1 (Glo1) and glyoxalase 2 (Glo2) form the complete glyoxalase pathway, which utilizes glutathione as cofactor in eukaryotic cells. The importance of Glo2 is highlighted by its ubiquitous distribution in prokaryotic and eukaryotic organisms. Its function in the system has been well defined, but in recent years, additional roles are emerging, especially those related to oxidative stress. This review focuses on Glo2 by considering its genetics, molecular and structural properties, its involvement in post-translational modifications and its interaction with specific metabolic pathways. The purpose of this review is to focus attention on an enzyme that, from th...
ABSTRACT Oncogenes deregulation is not enough to induce cellular prolifer- ation and tumorigenic transformation, which are caused by a variety of cooperating mechanisms. The oncogene Ras requires deregulation of other oncogenes or... more
ABSTRACT Oncogenes deregulation is not enough to induce cellular prolifer- ation and tumorigenic transformation, which are caused by a variety of cooperating mechanisms. The oncogene Ras requires deregulation of other oncogenes or inactivation of tumor sup- pressor proteins, such as p53, to increase the cell proliferation rate and to transform completely the cells. Expression of the con- stitutively activated oncogene H-RasV12 induces a proliferative arrest in normal fibroblasts due to senescence, apoptosis and autophagy, associated with DNA damage. H-RasV12 activation leads to an aberrant DNA replication increase, genomic instabil- ity and the activation of DNA Damage Response (DDR), which serves like tumorigenic barrier in pre-neoplastic lesion. In this work, we show that senescence induced in human fibroblasts by transfection with H-RasV12, is associated with DNA damage as well as with redox cellular imbalance. Flow cytometer analyses indicate that redox imbalance is due to both ROS increase and loss of mitochondrial membrane potential. Moreover, oxidative stress triggers important protein post-translational modifications by functional regulation via S-glutathionylation. Interestingly, in mono- and bi-dimensional electrophoresis there are evidences for the presence of different S-glutathionylation patterns in normal and activated H-RasV12 cells. It is known that protein S-glutath- ionylation is important both to the protection of protein cysteinyl groups sensitive to oxidative stress and to modulate the activity of several target proteins involved in tumor progression and/or cell death. In conclusion, H-RasV12 induced cellular redox imbalance and S-glutathionylation of target proteins may be associated to proliferative arrest and cellular death.
Raw cement asbestos (RCA) undergoes a complete solid state transformation when heated at high temperatures. The secondary raw material produced, high temperatures-cement asbestos (HT-CA) is composed of newly-formed crystals in place of... more
Raw cement asbestos (RCA) undergoes a complete solid state transformation when heated at high temperatures. The secondary raw material produced, high temperatures-cement asbestos (HT-CA) is composed of newly-formed crystals in place of the asbestos fibers present in RCA. Our previous study showed that HT-CA exerts lower cytotoxic cell damage compared to RCA. Nevertheless further investigations are needed to deepen our understanding of pathogenic pathways involving oxidative and nitrative damage. Our aim is to deepen the understanding of the biological effects on A549 cells of these materials regarding DNA damage related proteins (p53, its isoform p73 and TRAIL) and nitric oxide (NO) production during inducible nitric oxide synthase (iNOS)-mediated inflammation. Increments of p53/p73 expression, iNOS positive cells and NO concentrations were found with RCA, compared to HT-CA and controls mainly at 48 h. Interestingly, ferrous iron causing reactive oxygen species (ROS)-mediated DNA damage was found in RCA as a contaminant. HT-CA thermal treatment induces a global recrystallization with iron in a crystal form poorly released in media. HT-CA slightly interferes with genome expression and exerts lower inflammatory potential compared to RCA on biological systems. It could represent a safe approach for storing or recycling asbestos and an environmentally friendly alternative to asbestos waste.
S-glutathionylation involves the reversible formation of a mix disulphide-bridge between specific cysteine and a molecule of glutathione, the major non-protein antioxidant compound in the cell. Mechanisms of protein S-glutathionylation... more
S-glutathionylation involves the reversible formation of a mix disulphide-bridge between specific cysteine and a molecule of glutathione, the major non-protein antioxidant compound in the cell. Mechanisms of protein S-glutathionylation are far to be completely understood and several reactions can promote it, either spontaneously or catalyzed. For the first time Glo II enzyme was studied as a new potential candidate to promote S-glutathionylation. To demonstrate its active involvement in protein glutathionylation were used actin, malate dehydrogenase and GAPDH purified proteins, which are known to be glutathionylated, for in vitro experiments..This work shows active involvement of cytosolic Glo II for in vitro protein S-glutathionylation. To confirm the role of Glo II, preliminary protein-protein docking studies was performed between Glo II and human actin. The data showed a high propensity to aggregate with other proteins through its catalytic site Further, in silico investigation of Glo II stability and behavior, conducted through full atom molecular dynamics simulations, showed an high folding stability together with a great affinity towards its own reaction product glutathione both protonated (GSH) and unprotonated (GS(-)). These studies, revealed that GloII, using its natural substrate SLG, allow a rapid and specific protein-SSG formation, leading enzymatic regulation of S-glutathionylation in proteins of different origin and cellular compartmentalization.
In a previous study we showed that prediction tools are useful to select single-nucleotide polymorphisms (SNPs) which potentially affect phenotype and therefore guide genotyping in association studies, thus saving time and money. Here we... more
In a previous study we showed that prediction tools are useful to select single-nucleotide polymorphisms (SNPs) which potentially affect phenotype and therefore guide genotyping in association studies, thus saving time and money. Here we use the recently available RNA cross-link immunoprecipitation data to analyze several genes involved in psychiatric disorders and show which disease-associated SNPs can affect the splicing process by altering splicing factor binding sites. We point out the importance of using cross-link immunoprecipitation data in psychiatry to refine the SNP selection methods, to explain the association found and to plan molecular investigations.
Several forms of periodontal diseases (PD) are often associated with modified phagocytosing leukocytes and contemporary free radical production. Host antioxidant defenses could benefit from toothpastes used as adjuncts to counteract... more
Several forms of periodontal diseases (PD) are often associated with modified phagocytosing leukocytes and contemporary free radical production. Host antioxidant defenses could benefit from toothpastes used as adjuncts to counteract plaque-associated bacteria. The aim of the present study was to determine possible antioxidant activity (AA) of 12 differently antioxidant-enriched toothpastes, regardless of their efficacy as antimicrobial agents. Toothpastes were enriched alternatively with sodium ascorbyl phosphate, alpha-tocopherol acetate, pycnogenol, allantoin and methyl salycilate or a mixture of these. AA was tested in a cell-free system with a ABTS-decolorization assay improved by means of a flow injection analysis device. Comet assay, using NCTC 2544 keratinocytes, was performed to test if it was possible to identify any protection against in vitro DNA fragmentation provoked by a challenge with H(2)O(2) in cultures pre-incubated with toothpaste extracts. Only toothpastes containing sodium ascorbyl phosphate displayed clear AA with I(50) values ranging between 50 and 80 mg of toothpaste/ml water. COMET analysis of cells challenged with H(2)O(2) in presence of toothpaste extracts revealed a limited protection exerted by sodium ascorbyl phosphate. The results described herein indicate that toothpastes containing sodium ascorbyl phosphate possess AA. All the data were obtained in systems in vitro and the demonstration of in vivo AA is desirable. These findings could be useful in the treatment and maintenance of some forms of PD and should be considered when arranging new toothpaste formulations.
The objective of this work was to evaluate the capability of both seminal plasma and sperm cells to scavenge different forms of oxyradicals and the possible correlation with sperm motility parameters. A total of 14 individuals were... more
The objective of this work was to evaluate the capability of both seminal plasma and sperm cells to scavenge different forms of oxyradicals and the possible correlation with sperm motility parameters. A total of 14 individuals were analyzed by computer-assisted sperm analysis (CASA) and the results integrated with the measurement of total oxyradical scavenging capacity (TOSC) toward peroxyl radicals, hydroxyl radicals and peroxynitrite in seminal plasma and spermatozoa. TOSC values revealed some significant correlation with kinetic sperm cell parameters, including curvilinear velocity (VCL), straight-line velocity (VSL) and linearity (LIN). A lower antioxidant capacity toward hydroxyl radical was found in the seminal fluid of men with reduced sperm motility. Such correlations were not found with peroxyl radicals and peroxynitrite, neither when TOSC values were analyzed in spermatozoa. The TOSC assay is a useful tool for studying the relationship between oxyradical toxicity and abnormal sperm cell motility. Although further investigations are needed, the data clearly establish different role for various forms of oxyradicals, i.e., hydroxyl radicals, in altering sperm motility. Measurement of TOSC is suggested as a useful means of indicating relationship between reactive oxygen species and sperm cell kinetics in clinical trials and antioxidant-based treatments.
Studies of oxidative stress have classically been performed by analyzing specific, single antioxidants. In this study, susceptibility to oxidative stress in the human keratinocyte cell line NCTC2544 exposed to hydrogen peroxide (H2O2) was... more
Studies of oxidative stress have classically been performed by analyzing specific, single antioxidants. In this study, susceptibility to oxidative stress in the human keratinocyte cell line NCTC2544 exposed to hydrogen peroxide (H2O2) was measured by the TOSC (total oxyradical scavenging capacity) assay, which discriminates between the antioxidant capacity toward peroxyl radicals and hydroxyl radical. The generation of H2O2-induced DNA damage, total antioxidant capacity and levels of antioxidant enzymes (catalase, superoxide dismutase, glutathione reductase, glutathione S-transferase, glutathione peroxidase) were studied. Exposure to H2O2-induced DNA damage that was gradually restored while a significant reduction in cellular TOSC values was obtained independently of stressor concentrations and the degree of DNA repair. Whereas TOSC values and cell resistance to H2O2 showed a good relationship, the extent of DNA damage is independent from cellular total antioxidant capacity. Indeed, maximum DNA damage and cell mortality were observed in the first 4 h, whereas TOSC remained persistently low until 48 h. Catalase levels were significantly lower in exposed cells after 24 and 48 h. Keratinocytes exposed after 48 h to a second H2O2 treatment exhibited massive cell death. A possible linkage was observed between TOSC values and NCTC2544 resistance to H2O2 challenge. The TOSC assay appears to be a useful tool for evaluating cellular resistance to oxidative stress.
Liver ischemia/reperfusion is frequently associated with organ injury to which reactive oxygen species contribute. The aim of our study was to evaluate cytosolic and mitochondrial glutathione levels and morphological changes in... more
Liver ischemia/reperfusion is frequently associated with organ injury to which reactive oxygen species contribute. The aim of our study was to evaluate cytosolic and mitochondrial glutathione levels and morphological changes in hepatocytes of rat liver in an experimental model of ischemia/reperfusion. The experimental procedure consisted of temporary interruption of blood flow to the left lateral and medial hepatic lobes for different lengths of time and, in some cases, subsequent reperfusion. Cytosolic and mitochondrial glutathione levels were evaluated and ultrastructural analysis was carried out for all samples. Ischemic lobes showed ultrastructural changes in relationship with the increase in ischemia time. Total glutathione levels did not show variations in ischemic lobes and sham lobes with respect to control rats during ischemia only. Instead, during reperfusion, significant ultrastructural alterations of the hepatocytes and a significant depletion of glutatione in cytosolic and mitochondrial compartments were evident. The sham lobes also showed a significant glutathione decrement. Increased oxidized glutathione (GSSG) levels were found during ischemia both in ischemic lobes and in sham lobes. During reperfusion GSSG was found to a minor extent, in the cytosolic compartment. In mitochondria GSSG levels were also high during reperfusion. We conclude that depletion of glutathione contributes to impaired liver after reperfusion following ischemia but depletion of glutathione alone does not induce changes in the morphology of the hepatocytes. Glutathione depletion and a greater quantity of GSSG, even in sham lobes, may indicate a metabolic alteration which spreads to compartments that are not involved in ischemia/reperfusion.
Protection of mitochondria during cold storage of liver and following transplantation: comparison of the two solutions,
Synthetic nitrone spin-traps are being explored as therapeutic agents for the treatment of a wide range of oxidative stress-related pathologies, including but not limited to stroke, cancer, cardiovascular, and neurodegenerative diseases.... more
Synthetic nitrone spin-traps are being explored as therapeutic agents for the treatment of a wide range of oxidative stress-related pathologies, including but not limited to stroke, cancer, cardiovascular, and neurodegenerative diseases. In this context, increasing efforts are currently being made to the design and synthesis of new nitrone-based compounds with enhanced efficacy. The most researched nitrones are surely the ones related to α-phenyl-tert-butylnitrone (PBN) and 5,5-dimethyl-1-pyrroline N-oxide (DMPO) derivatives, which have shown to possess potent biological activity in many experimental animal models. However, more recently, nitrones with a benzoxazinic structure (3-aryl-2H-benzo[1,4]oxazin-N-oxides) have been demonstrated to have superior antioxidant activity compared to PBN. In this study, two new benzoxazinic nitrones bearing an electron-withdrawing methoxycarbonyl group on the benzo moiety (in para and meta positions respect to the nitronyl function) were synthesiz...
Glutathione is a very ancient molecule widely distributed in aerobic cells and organisms, either prokaryotes or eukaryotes. Since glutathione in not found in anaerobic cells it could have evolved in the course of the adaptation to the... more
Glutathione is a very ancient molecule widely distributed in aerobic cells and organisms, either prokaryotes or eukaryotes. Since glutathione in not found in anaerobic cells it could have evolved in the course of the adaptation to the presence of oxygen in the atmosphere. Glutathione is the major non-protein low molecular weight antioxidant and the most important cellular thiol reducing agent. Glutathione biosynthesis occurs in the cytosol from its constituent amino acids; GSH is present also in the most important cellular districts like mitochondria and nucleus to indicate its central role in several metabolic pathways and protective mechanisms. There are several glutathione dependent enzymes involved in various steps of cell metabolism. GSH is a key antioxidant that modulates various cellular processes and therefore is determinant for redox signaling, xenobiotics’s detoxication, regulation of cell proliferation, apoptosis and immune functions. Glutathione concentration and redox state is due to a complex interaction between biosynthesis, utilization, degradation, and transport. All these factors are of great importance for understanding the significance of cellular redox balance and its correlation with pathological conditions.
Cerebral Cavernous Malformations (CCM; OMIM 116860) are a cerebrovascular malformations characterized by abnormally enlarged and leaky capillaries that predispose to seizures, focal neurological deficits, and fatal intracerebral... more
Cerebral Cavernous Malformations (CCM; OMIM 116860) are a cerebrovascular malformations characterized by abnormally enlarged and leaky capillaries that predispose to seizures, focal neurological deficits, and fatal intracerebral haemorrhage (1). CCMs are characterized by familial and sporadic form and three gene are been identified: CCM1/KRIT1, CCM2/MGC4607 and CCM3/PDCD10 (2). In particular CCM disease has been associated with several mutations in KRIT1 gene and the protein encoded plays an important role in molecular mechanisms involved in the maintenance of the cellular redox balance (3-5). In this study we found that KRIT1 loss/down-regulation is associated with a significant increase in intracellular ROS levels and with a significant decrease in total antioxidant capacity towards hydroxyl radical. Moreover we found a significant decrease of GSH level and significant activity and expression decrease of the GST. Furthermore, we demonstrate that the redox imbalance in KRIT1-/- cel...
The epidermal growth factor receptor (EGFR) is one of the most well-studied molecular targets in non-small cell lung cancer (NSCLC) and tyrosine kinase inhibitors have been shown to be effective in the treatment of advanced NSCLC.... more
The epidermal growth factor receptor (EGFR) is one of the most well-studied molecular targets in non-small cell lung cancer (NSCLC) and tyrosine kinase inhibitors have been shown to be effective in the treatment of advanced NSCLC. Nevertheless, the efficacy of tyrosine kinase inhibitors could be compromised by additional mutations in EGFR and compensatory activations of other pathways. Epigallocatechin-3-gallate (EGCG), the main bioactive molecule in green tea, acts as a tyrosine kinase inhibitor toward cancer cells overexpressing EGFR (wild-type). However, little information has been reported on the effect of EGCG on EGFR with activating mutations. In this study, we evaluated the ability of EGCG to inhibit EGFR signaling activation in three different NSCLC cell lines containing wild-type EGFR or EGFR with additional mutations. The effect on proliferation, apoptosis, migration, and vinculin expression was then studied. Overall, our results demonstrate that EGCG polyphenol inhibits c...
The use of glyceryl monooleate (GMO)-based nanoparticles has not yet been explored in overcoming the low bioavailability of Epigallocatechin-3-gallate (EGCG), a green tea polyphenol with a known anticancer activity. Since the inclusion of... more
The use of glyceryl monooleate (GMO)-based nanoparticles has not yet been explored in overcoming the low bioavailability of Epigallocatechin-3-gallate (EGCG), a green tea polyphenol with a known anticancer activity. Since the inclusion of a guest molecule can affect the curvature and the supramolecular structure of fully hydrated GMO-based phase, the phase behavior of bulk and dispersed liquid crystalline systems containing EGCG were explored by Small Angle Neutron Scattering and X-Ray Diffraction experiments. Molecular Dynamic Simulations showed how the interaction of EGCG with polar heads of GMO strongly affects the curvature and packing of GMO phase. The EGCG encapsulation efficiency was determined in the nanodispersions and their size studied by Dynamic Light Scattering and Atomic Force Microscopy. A nanodispersed formulation has been optimized with a cytotoxic effect more than additive of GMO and EGCG.
Reactive oxygen species (ROS) are produced constantly inside the cells as a consequence of nutrient catabolism. The balance between ROS production and elimination allows to maintain cell redox homeostasis and biological functions,... more
Reactive oxygen species (ROS) are produced constantly inside the cells as a consequence of nutrient catabolism. The balance between ROS production and elimination allows to maintain cell redox homeostasis and biological functions, avoiding the occurrence of oxidative distress causing irreversible oxidative damages. A fundamental player in this fine balance is reduced glutathione (GSH), required for the scavenging of ROS as well as of the reactive 2-oxoaldehydes methylglyoxal (MGO). MGO is a cytotoxic compound formed constitutively as byproduct of nutrient catabolism, and in particular of glycolysis, detoxified in a GSH-dependent manner by the glyoxalase pathway consisting in glyoxalase I and glyoxalase II reactions. A physiological increase in ROS production (oxidative eustress, OxeS) is promptly signaled by the decrease of cellular GSH/GSSG ratio which can induce the reversible S-glutathionylation of key proteins aimed at restoring the redox balance. An increase in MGO level also o...
S-glutathionylation, the reversible formation of a mixed disulfide bridge between a specific cysteine and a glutathione molecule, can occur spontaneously or be catalyzed by enzymes. Glyoxalase II (GloII), using its natural substrate SLG... more
S-glutathionylation, the reversible formation of a mixed disulfide bridge between a specific cysteine and a glutathione molecule, can occur spontaneously or be catalyzed by enzymes. Glyoxalase II (GloII), using its natural substrate SLG can form specific protein-SSG mixed disulfide leading enzymatic regulation of S-glutathionylation.
Chronic high glucose (HG) exposure increases methylglyoxal (MG)-derived AGEs and is involved in the onset of pathological conditions, such as diabetes, atherosclerosis and chronic‐degenerative diseases. Under physiologic condition the... more
Chronic high glucose (HG) exposure increases methylglyoxal (MG)-derived AGEs and is involved in the onset of pathological conditions, such as diabetes, atherosclerosis and chronic‐degenerative diseases. Under physiologic condition the harmful effects of MG are contrasted by glyoxalase system that is involved in the detoxification of Reactive Carbonyl Species (RCS) and maintain the homeostasis of the redox environment of the cell. Polyphenols are the most abundant antioxidants in the diet and present various health benefits. The study aimed at investigating the role of polyphenols extracted from an apple high in polyphenols (Calville White Winter), on glyco-oxidative stress induced by chronic HG-exposure. Intestinal Caco-2 cells were treated in physiological glucose condition (25mM) as a control and in HG condition (50mM) with or without apple extract for one week. Our data demonstrated that HG-treatment triggers glyco-oxidation stress with a significantly increase in ROS, lipid pero...
Dicarbonyl stress is a dysfunctional state consisting in the abnormal accumulation of reactive α-oxaldehydes leading to increased protein modification. In cells, post-translational changes can also occur through S-glutathionylation, a... more
Dicarbonyl stress is a dysfunctional state consisting in the abnormal accumulation of reactive α-oxaldehydes leading to increased protein modification. In cells, post-translational changes can also occur through S-glutathionylation, a highly conserved oxidative post-translational modification consisting of the formation of a mixed disulfide between glutathione and a protein cysteine residue. This review recapitulates the main findings supporting a role for dicarbonyl stress and S-glutathionylation in the pathogenesis of cerebrovascular diseases, with specific emphasis on cerebral cavernous malformations (CCM), a vascular disease of proven genetic origin that may give rise to various clinical signs and symptoms at any age, including recurrent headaches, seizures, focal neurological deficits, and intracerebral hemorrhage. A possible interplay between dicarbonyl stress and S-glutathionylation in CCM is also discussed.
Resveratrol (RES) is a stilbenoid polyphenol with interesting antitumor activity compromised by its poor solubility and bioavailability; thus, new approaches are necessary to improve its therapeutic effectiveness. In the present study,... more
Resveratrol (RES) is a stilbenoid polyphenol with interesting antitumor activity compromised by its poor solubility and bioavailability; thus, new approaches are necessary to improve its therapeutic effectiveness. In the present study, bovine serum albumin coated layered double hydroxide (LDH–BSA) was employed to encapsulate RES in order to overcome the above-mentioned usage limits. To evaluate the feasibility of neutral RES complexation with cationic LDH, we carried out molecular dynamics simulation in order to predict its structure and stability. In the supramolecular complex formed with LDH, RES disposes itself in the interlamellar region of LDH where it is stabilized by intermolecular interactions. The physico-chemical characteristics of the resulting nanocomplexes were studied by X-ray powder diffraction, transmission electron microscopy, and attenuated total reflection Fourier transform infrared spectroscopy. The encapsulation efficiency and drug release studies were also perf...
Glyoxalase II has been docked with actin and malate dehydrogenase and a direct involvement of the GlxII active site was found. The presence of GSH in the GlxII catalytic site promotes the protein–protein stabilization.
Loss-of-function mutations in the KRIT1 gene are associated with the pathogenesis of cerebral cavernous malformations (CCMs), a major cerebrovascular disease still awaiting therapies. Accumulating evidence demonstrates that KRIT1 plays an... more
Loss-of-function mutations in the KRIT1 gene are associated with the pathogenesis of cerebral cavernous malformations (CCMs), a major cerebrovascular disease still awaiting therapies. Accumulating evidence demonstrates that KRIT1 plays an important role in major redox-sensitive mechanisms, including transcriptional pathways and autophagy, which play major roles in cellular homeostasis and defense against oxidative stress, raising the possibility that KRIT1 loss has pleiotropic effects on multiple redox-sensitive systems. Using previously established cellular models, we found that KRIT1 loss-of-function affects the glutathione (GSH) redox system, causing a significant decrease in total GSH levels and increase in oxidized glutathione disulfide (GSSG), with a consequent deficit in the GSH/GSSG redox ratio and GSH-mediated antioxidant capacity. Redox proteomic analyses showed that these effects are associated with increased S-glutathionylation of distinct proteins involved in adaptive r...
Reactive oxygen species (ROS) production in the skin is among the highest compared to other organs, and a clear correlation exists between ROS production and skin aging. Many attempts are underway to reduce oxidative stress in the skin by... more
Reactive oxygen species (ROS) production in the skin is among the highest compared to other organs, and a clear correlation exists between ROS production and skin aging. Many attempts are underway to reduce oxidative stress in the skin by topical treatment or supplementation with antioxidants/cosmeceuticals, and cultures of human dermal fibroblasts (HDF) are widely used for these studies. Here, we examined the influence of oxygen tension on cell aging in HDF and how this impacted ROS production, the enzymatic and nonenzymatic antioxidant response system, and the efficacy of this defense system in limiting DNA damage and in modulating gene expression of proteins involved in the extracellular matrix, linked to skin aging. We investigated a selection of parameters that represent and reflect the behavior of cellular responses to aging and oxygen tension. Serial passaging of HDF under normoxia (21%) and hypoxia (5%) leads to cell aging as confirmed by -galactosidase activity, p16 express...
Abstract Liposomes are versatile platforms to carry anticancer drugs in targeted drug delivery; they can be surface modified by different strategies and, when coupled with targeting ligands, are able to increase cellular internalisation... more
Abstract Liposomes are versatile platforms to carry anticancer drugs in targeted drug delivery; they can be surface modified by different strategies and, when coupled with targeting ligands, are able to increase cellular internalisation and organelle-specific drug delivery. An interesting strategy of antitumoral therapy could involve the use of lysosomotropic ligand-targeted liposomes loaded with molecules, which can induce lysosomal membrane permeabilization (LMP), leakage of cathepsins into the cytoplasm and subsequent apoptosis. We have previously demonstrated the ability of liposomes functionalised with a mannose-6-phosphate to reach lysosomes; in this research we compare the behaviour of M6P-modified and non-functionalised liposomes in MCF7 tumour cell and in HDF normal cells. With this aim, we first demonstrated by Western blotting the overexpression of mannose-6-phosphate/insulin-like growth factor (M6P/IGF-II) receptor in MCF7. Then, we prepared calcein-loaded liposomes and we revealed the increased uptake of M6P-functionalised liposomes in MCF7 cells respect to HDF cells by flow cytometry analysis. Finally, we loaded functionalised and not functionalised liposomes with N-hexanoyl-d-erythro-sphingosine (C6Cer), able to initiate LMP-induced apoptosis; after having studied the stability of both vesicles in the presence of serum by Dynamic Light Scattering and Spectrophotometric turbidity measurements, we showed that ceramide-loaded M6P-liposomes significantly increased apoptosis in MCF7 with respect to HDF cells.
Glyoxalase II, the second of 2 enzymes in the glyoxalase system, is a hydroxyacylglutathione hydrolase that catalyses the hydrolysis of S-d-lactoylglutathione to form d-lactic acid and glutathione, which is released from the active site.... more
Glyoxalase II, the second of 2 enzymes in the glyoxalase system, is a hydroxyacylglutathione hydrolase that catalyses the hydrolysis of S-d-lactoylglutathione to form d-lactic acid and glutathione, which is released from the active site. The tripeptide glutathione is the major sulfhydryl antioxidant and has been shown to control several functions, including S-glutathionylation of proteins. S-Glutathionylation is a way for the cells to store reduced glutathione during oxidative stress, or to protect protein thiol groups from irreversible oxidation, and few enzymes involved in protein S-glutathionylation have been found to date. In this work, the enzyme glyoxalase II and its substrate S-d-lactoylglutathione were incubated with malate dehydrogenase or with actin, resulting in a glutathionylation reaction. Glyoxalase II was also submitted to docking studies. Computational data presented a high propensity of the enzyme to interact with malate dehydrogenase or actin through its catalytic ...

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