Background
Cutaneous neoplasms include melanoma and non‐melanoma skin cancers (NMSCs). Among NMSCs, basal cell carcinoma (BCC) represents the most common lesion. On the contrary, although accounting ...for less than 5% of all skin cancers, melanoma is responsible for most of cutaneous malignancy‐related deaths. Paraoxonase‐2 (PON2) is an intracellular enzyme exerting a protective role against production of reactive oxygen species within mitochondrial respiratory chain. Recently, a growing attention has been focused on exploring the role of PON2 in cancer. The aim of this study was to investigate the diagnostic and prognostic role of PON2 in skin neoplasms.
Materials and methods
36 cases of BCC, distinguished between nodular and infiltrative lesions, as well as 29 melanoma samples were analysed by immunohistochemistry to evaluate PON2 protein expression. Subsequent statistical analyses were carried out to explore the existence of correlations between intratumour enzyme levels and clinicopathological features.
Results
Results obtained showed PON2 overexpression in BCCs compared with controls. In particular, distinguishing between less and more aggressive tumour forms, we found no significant differences in enzyme levels between nodular BCCs and controls. Conversely, PON2 expression was significantly higher in infiltrative BCCs compared with controls. Moreover, the enzyme was strongly upregulated in melanoma samples with respect to controls. Interestingly, PON2 levels were positively correlated with Breslow thickness, Clark level, regression, mitoses, lymph node metastases, primary tumour (pT) parameter and pathological stage.
Conclusions
Reported findings seem to suggest that PON2 expression levels could be positively related with tumour aggressiveness of both BCC and melanoma.
Proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to and degrades the low-density lipoprotein receptor (LDLR), contributing to hypercholesterolemia. Adipose tissue plays a role in ...lipoprotein metabolism, but there are almost no data about PCSK9 and LDLR regulation in human adipocytes. We studied PCSK9 and LDLR regulation by insulin, atrial natriuretic peptide (ANP, a potent lipolytic agonist that antagonizes insulin), and LDL in visceral adipose tissue (VAT) and in human cultured adipocytes.
was expressed in VAT and its expression was positively correlated with body mass index (BMI). Both intracellular mature and secreted PCSK9 were abundant in cultured human adipocytes. Insulin induced PCSK9, LDLR, and sterol-regulatory element-binding protein-1c (SREBP-1c) and -2 expression (SREBP-2). ANP reduced insulin-induced PCSK9, especially in the context of a medium simulating hyperglycemia. Human LDL induced both mature and secreted PCSK9 and reduced LDLR. ANP indirectly blocked the LDLR degradation, reducing the positive effect of LDL on PCSK9. In conclusion,
is expressed in human adipocytes. When the expression of PCSK9 is induced, LDLR is reduced through the PCSK9-mediated degradation. On the contrary, when the induction of PCSK9 by insulin and LDL is partially blocked by ANP, the LDLR degradation is reduced. This suggests that NPs could be able to control LDLR levels, preventing PCSK9 overexpression.
Spices, widely used to improve the sensory characteristics of food, contain several bioactive compounds as well, including polyphenols, carotenoids, and glucosynolates. Acting through multiple ...pathways, these bioactive molecules affect a wide variety of cellular processes involved in molecular mechanisms important in the onset and progress of human diseases. Capparis spinosa L. is an aromatic plant characteristic of the Mediterranean diet. Previous studies have reported that different parts (aerial parts, roots, and seeds) of C. spinosa exert various pharmacological activities. Flower buds of C. spinosa contain several bioactive compounds, including polyphenols and glucosinolates. Two different subspecies of C. spinosa L., namely, C. spinosa L. subsp. spinosa, and C. spinosa L. subsp. rupestris, have been reported. Few studies have been carried out in C. spinosa L. subsp. rupestris. The aim of our study was to investigate the phytochemical profile of floral buds of the less investigated species C. spinosa subsp. rupestris. Moreover, we investigated the effect of the extract from buds of C. spinosa subsp. rupestris (CSE) on cell proliferation, intracellular ROS levels, and expression of the antioxidant and anti-apoptotic enzyme paraoxonase-2 (PON2) in normal and cancer cells. T24 cells and Caco-2 cells were selected as models of advanced-stage human bladder cancer and human colorectal adenocarcinoma, respectively. The immortalized human urothelial cell line (UROtsa) and human dermal fibroblast (HuDe) were chosen as normal cell models. Through an untargeted metabolomic approach based on ultra-high-performance liquid chromatography quadrupole-time-of-flight mass spectrometry (UHPLC-QTOF-MS), our results demonstrate that C. spinosa subsp. rupestris flower buds contain polyphenols and glucosinolates able to exert a higher cytotoxic effect and higher intracellular reactive oxygen species (ROS) production in cancer cells compared to normal cells. Moreover, upregulation of the expression of the enzyme PON2 was observed in cancer cells. In conclusion, our data demonstrate that normal and cancer cells are differentially sensitive to CSE, which has different effects on PON2 gene expression as well. The overexpression of PON2 in T24 cells treated with CSE could represent a mechanism by which tumor cells protect themselves from the apoptotic process induced by glucosinolates and polyphenols.
Low-density lipoproteins (LDLs) exert a key role in the transport of esterified cholesterol to tissues. Among the atherogenic modifications of LDLs, the oxidative modification has been mainly ...investigated as a major risk factor for accelerating atherogenesis. Since LDL sphingolipids are also emerging as important regulators of the atherogenic process, increasing attention is devoted to the effects of sphingomyelinase (SMase) on LDL structural and atherogenic properties. The aims of the study were to investigate the effect of SMase treatment on the physical-chemical properties of LDLs. Moreover, we evaluated cell viability, apoptosis, and oxidative and inflammatory status in human umbilical vein endothelial cells (HUVECs) treated with either ox-LDLs or SMase-treated LDLs (SMase-LDLs). Both treatments were associated with the accrual of the intracellular ROS and upregulation of the antioxidant Paraoxonase 2 (PON2), while only SMase-LDLs induced an increase of superoxide dismutase 2 (SOD2), suggesting the activation of a feedback loop to restrain the detrimental effects of ROS. The increased caspase-3 activity and reduced viability observed in cells treated with SMase-LDLs and ox-LDLs suggest a pro-apoptotic effect of these modified lipoproteins on endothelial cells. Moreover, a strong proinflammatory effect of SMase-LDLs compared to ox-LDLs was confirmed by an increased activation of NF-κB and consequent increased expression of its downstream cytokines IL-8 and IL-6 in HUVECs.
High‐density lipoproteins (HDLs) play a key role in the protection against oxidative damage. The enzyme paraoxonase‐1 (PON1) associated at the surface of HDL modulates the antioxidant and ...anti‐inflammatory role of HDL. Previous studies have demonstrated a decrease of serum PON in obese patients. The aim of this study was to investigate whether modifications of PON1 activity reflect in a different ability to protect and/or repair biological membranes against oxidative damage. Thirty obese patients at different grades of obesity (BMI ranging from 30.4 to 64.0 kg/m2) and 62 age‐matched control subjects (BMI <25 kg/m2) were included in the study. The ability of HDL to protect membranes against oxidative damage was studied using erythrocyte membranes oxidized with 2,2‐azobis(2 amidinopropane)dihydrochloride (AAPH) (ox‐membrane). The membrane lipid hydroperoxide levels were evaluated after the incubation of ox‐membranes in the absence or in the presence of HDL of controls or obese patients. The results confirm that HDL exerts a protective effect against lipid peroxidation. The ability of HDL to repair erythrocyte membranes was positively correlated with HDL‐PON activity and negatively correlated with lipid hydroperoxide levels in HDL. These results suggest that PON modulates the HDL repairing ability. HDL from obese patients repaired less efficiently erythrocyte membranes against oxidative damage with respect to HDL from healthy subjects. A negative relationship has been established between BMI of obese patients and the protective effect of HDL. In conclusion, the decrease of HDL‐PON activity and the lower HDL protective action against membrane peroxidation in obese patients could contribute to accelerate the cellular oxidative damage and arteriosclerosis in obesity.
Abstract Objective Methylglyoxal (MG), a reactive carbonyl compound formed primarily from triose phosphates, appears to be involved in the molecular mechanisms of diabetes, end-stage renal disease ...and neurodegenerative diseases. Methylglyoxal exerts several biological activities. Among these it promotes advanced glycation end products (AGEs), which are crucial in pathogenesis of human disease. Previous studies have demonstrated that MG reacts with proteins and compositional modifications reflect loss of biological activity. The aim of the study was to investigate the effect of in vitro MG-induced glycation on human high density lipoprotein (HDL) and on the activity of the enzyme paraoxonase-1 (PON1). Methods HDL was incubated in the absence or in the presence of MG (0.2 mmol/L and 1.0 mmol/L) (MG-HDL) for different times (3, 6, 24 h) at 37 ° C. We evaluated apoprotein compositional changes, in both control and MG treated HDL, using intrinsic fluorescence of tryptophan and monitoring the decrease of free amino groups. Furthermore we evaluated fluorescent advanced glycation end products (Ex = 370 nm, Em = 440 nm) and the activity of HDL-paraoxonase. Results We demonstrated that human HDL is susceptible to glycation by MG (0.2 mmol/L and 1 mmol/L). The decrease of free amino groups and of intrinsic fluorescence of tryptophan demonstrates HDL apoprotein modifications in HDL incubated with MG. The compositional changes are associated with a significant increase in fluorescent advanced glycation end products and with a significant decrease of paraoxonase-1 enzyme activity associated with the HDL surface. Conclusions HDL-associated paraoxonase is responsible for the anti-inflammatory and anti-oxidative properties of HDL and detoxification against homocysteine-thiolactone. Therefore, modifications of apoprotein composition and the decrease of paraoxonase-1 activity in MG-treated HDL could affect the protective effect exerted by HDL against oxidative damage and could contribute to complications in patients affected by diseases associated with aging and oxidative stress.
Posidonia oceanica (L.) Delile is an endemic Mediterranean marine plant of extreme ecological importance. Previous in vitro and in vivo studies have demonstrated the potential antidiabetic properties ...of P. oceanica leaf extract. Intestinal glucose transporters play a key role in glucose homeostasis and represent novel targets for the management of diabetes. In this study, the ability of a hydroalcoholic P. oceanica leaf extract (POE) to modulate intestinal glucose transporters was investigated using Caco-2 cells as a model of an intestinal barrier. The incubation of cells with POE significantly decreased glucose uptake by decreasing the GLUT2 glucose transporter levels. Moreover, POE had a positive effect on the barrier integrity by increasing the Zonulin-1 levels. A protective effect exerted by POE against oxidative stress induced by chronic exposure to high glucose concentrations or tert-butyl hydroperoxide was also demonstrated. This study highlights for the first time the effect of POE on glucose transport, intestinal barrier integrity, and its protective antioxidant effect in Caco-2 cells. These findings suggest that the P. oceanica phytocomplex may have a positive impact by preventing the intestinal cell dysfunction involved in the development of inflammation-related disease associated with oxidative stress.
Objectives: Physical exercise significantly impacts the biochemistry of the organism. Ubiquinone is a key component of the mitochondrial respiratory chain and ubiquinol, its reduced and active form, ...is an emerging molecule in sport nutrition. The aim of this study was to evaluate the effect of ubiquinol supplementation on biochemical and oxidative stress indexes after an intense bout of exercise.
Methods: 21 male young athletes (26 + 5 years of age) were randomized in two groups according to a double blind cross-over study, either supplemented with ubiquinol (200 mg/day) or placebo for 1 month. Blood was withdrawn before and after a single bout of intense exercise (40 min run at 85% maxHR). Physical performance, hematochemical parameters, ubiquinone/ubiquinol plasma content, intracellular reactive oxygen species (ROS) level, mitochondrial membrane depolarization, paraoxonase activity and oxidative DNA damage were analyzed.
Results: A single bout of intense exercise produced a significant increase in most hematochemical indexes, in particular CK and Mb while, on the contrary, normalized coenzyme Q
10
plasma content decreased significantly in all subjects. Ubiquinol supplementation prevented exercise-induced CoQ deprivation and decrease in paraoxonase activity. Moreover at a cellular level, in peripheral blood mononuclear cells, ubiquinol supplementation was associated with a significant decrease in cytosolic ROS while mitochondrial membrane potential and oxidative DNA damage remained unchanged.
Discussion: Data highlights a very rapid dynamic of CoQ depletion following intense exercise underlying an increased demand by the organism. Ubiquinol supplementation minimized exercise-induced depletion and enhanced plasma and cellular antioxidant levels but it was not able to improve physical performance indexes or markers of muscular damage.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Anti-virulence strategies are being explored as a novel approach to combat pathogens. Such strategies include inhibition of surface adhesion, tissue invasion, toxin production, and/or interference ...with the gene regulation of other virulence traits.
, the causative agent of listeriosis, is a facultative intracellular food pathogen characterized by a wide distribution in the environment. Its ability to persist within biofilms and to develop resistance to sanitizers is the cause of significant problems in food processing plants and of steep costs for the food industry. In humans, the treatment of listeriosis is hampered by the intracellular location of listeriae and the poor intracellular penetration of some antibiotics. Eleven
isolates from patients who were diagnosed with invasive listeriosis in Italy in 2014-2016 were studied. This
and
study explored the antibacterial and anti-virulence properties of a steam-distilled essential oil of
L., which is being intensively investigated for its high content in powerful bioactive phytochemicals. Susceptibility experiments demonstrated a moderate bactericidal activity of the essential oil (Minimum Bactericidal Concentration > 2048 μg/mL). Assessment of the effects of sublethal concentrations of the essential oil on
virulence traits demonstrated a significant action on motility. Listeriae were non-motile after exposure to the essential oil. Light and scanning electron microscopy documented aggregates of listeriae with the flagella trapped inside the cluster. Real-time RT-PCR experiments showed downregulation of flagellar motility genes and of the regulatory gene
. The ability to form biofilm and to invade Caco-2 cells was also significantly reduced.
larvae infected with
grown in presence of sublethal concentrations of the essential oil showed much higher survival rates compared with controls, suggesting that the extract inhibited tissue invasion. Food contamination with
is a major concern for the food industry, particularly for plants making ready-to-eat and processed food. The present work provides a baseline in the study of the anti-virulence properties of the
essential oil against
. Further studies are needed to understand if it could be used as an alternative agent for the control of
in food processing plants.
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