Land uses in cities and their impacts on the water quality of urban freshwater blue spaces in the Pampean region (Argentina).

Freshwater blue spaces (FBS), such as ponds, are key elements of the urban landscape and are under strong anthropogenic pressure. Land-use types and diversity may exert a negative or positive impact on FBS' water quality depending on their nature and arrangement. The information available in this respect is remarkably scarcer for water bodies in the Global South than for the north. Thus, we aim to identify and quantify the land-use types in a 500-m buffer zone of urban ponds in the Pampean region (Argentina) to assess their impact on water quality. We based our study on 15 FBS located in neighborhoods of Buenos Aires province during cold and warm seasons. We analyzed physical, chemical, and biological variables, and estimated water conditions by means of water quality indexes (WQIs) and quality guidelines. We quantified the dominant land-use type and the diversity of uses in the ponds' buffer zones, and evaluated their relationships with WQIs. Our results showed that WQIs were negatively related to a high proportion of residential areas in the adjacent zone, while positively to recreational ones. The diversity of land uses did not influence the water quality. We propose a new WQIpond with fewer key response variables, and as sensitive as the currently used WQIobjetive. We conclude that water quality from urban ponds in the Pampean region can be affected by dominant land-use type in the adjacent area but also the quality of their water supply sources (superficial and/or underground), clandestine wastewater discharges, and non-point pollution.

Downstream effects of endocannabinoid on blood cells: implications for health and disease.

Endocannabinoids (eCBs), among which N-arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG) are the most biologically active members, are polyunsaturated lipids able to bind cannabinoid, vanilloid and peroxisome proliferator-activated receptors. Depending on the target engaged, these bioactive mediators can regulate different signalling pathways, at both central and peripheral levels. The biological action of eCBs is tightly controlled by a plethora of metabolic enzymes which, together with the molecular targets of these substances, form the so-called "endocannabinoid system". The ability of eCBs to control manifold peripheral functions has received a great deal of attention, especially in the light of their widespread distribution in the body. In particular, eCBs are important regulators in blood, where they modulate haematopoiesis, platelet aggregation and apoptosis, as well as chemokine release and migration of immunocompetent cells. Here, we shall review the current knowledge on the pathophysiological roles of eCBs in blood. We shall also discuss the involvement of eCBs in those disorders affecting the haematological system, including cancer and inflammation. Knowledge gained to date underlines a fundamental role of the eCB system in blood, thus suggesting that it may represent a therapeutic promise for a broad range of diseases involving impaired hematopoietic cell functions.

Obesity-associated oxidative stress: strategies finalized to improve redox state.

Obesity represents a major risk factor for a plethora of severe diseases, including diabetes, cardiovascular disease, non-alcoholic fatty liver disease, and cancer. It is often accompanied by an increased risk of mortality and, in the case of non-fatal health problems, the quality of life is impaired because of associated conditions, including sleep apnea, respiratory problems, osteoarthritis, and infertility. Recent evidence suggests that oxidative stress may be the mechanistic link between obesity and related complications. In obese patients, antioxidant defenses are lower than normal weight counterparts and their levels inversely correlate with central adiposity; obesity is also characterized by enhanced levels of reactive oxygen or nitrogen species. Inadequacy of antioxidant defenses probably relies on different factors: obese individuals may have a lower intake of antioxidant- and phytochemical-rich foods, such as fruits, vegetables, and legumes; otherwise, consumption of antioxidant nutrients is normal, but obese individuals may have an increased utilization of these molecules, likewise to that reported in diabetic patients and smokers. Also inadequate physical activity may account for a decreased antioxidant state. In this review, we describe current concepts in the meaning of obesity as a state of chronic oxidative stress and the potential interventions to improve redox balance.

The endocannabinoid system and its relevance for nutrition.

Endocannabinoids bind to cannabinoid, vanilloid, and peroxisome proliferator-activated receptors. The biological actions of these polyunsaturated lipids are controlled by key agents responsible for their synthesis, transport and degradation, which together form an endocannabinoid system (ECS). In the past few years, evidence has been accumulated for a role of the ECS in regulating food intake and energy balance, both centrally and peripherally. In addition, up-regulation of the ECS in the gastrointestinal tract has a potential impact on inflammatory bowel diseases. In this review, the main features of the ECS are summarized in order to put in better focus our current knowledge of the nutritional relevance of endocannabinoid signaling and of its role in obesity, cardiovascular pathologies, and gastrointestinal diseases. The central and peripheral pathways that underlie these effects are discussed, as well as the possible exploitation of ECS components as novel drug targets for therapeutic intervention in eating disorders.

Anandamide extends platelets survival through CB(1)-dependent Akt signaling.

Platelets are stored at 22 degrees C, since incubation at 37 degrees C results in loss of viability. Nonetheless, in our body (37 degrees C), platelets survive for 8-10 days. This discrepancy has been explained in terms of deprivation of viability factors or accumulation of apoptotic factors during storage. We report that the endocannabinoid anandamide (AEA) may be one of the agents allowing platelet survival. In fact, at 37 degrees C, human platelets enhance the expression of pro-apoptotic proteins (caspases, Bax, Bak) and decrease the expression of Bcl-xL, thus changing the Bcl-xL/Bak ratio, a key platelet biological clock. AEA or its non-hydrolyzable analogue, methanandamide, extend platelet life span, without reversing the changes in Bcl-xL/Bak ratio induced by heat stress. Instead, AEA binding to type-1 cannabinoid receptor activates Akt, which regulates, through phosphorylation of Bad, the interactions among different Bcl-2 family members. These findings could have implications for platelet collection and, potentially, for their clinical use.

Redox modulation of Ecto-NOX1 in human platelets.

By modulating the cellular redox state, the plasma membrane electron transport (PMET) is important in platelet biology; indeed, the oxidant/antioxidant balance plays a central role during activation of the coagulation pathway. None the less, in human platelets, the PMET system has not yet been fully characterized and the molecular identities of most components are unknown. Here, for the first time, the presence of the plasma membrane hydroquinone (NADH) oxidase Ecto-NOX1 in human platelets has been described. We found that Ecto-NOX1 expression is modulated by capsaicin: Indeed, it is positively regulated through a mechanism requiring binding of capsaicin to its receptor, namely the transient receptor potential vanilloid subtype 1 (TRPV1). Ligand-receptor interaction triggers a signalling cascade leading to ROS production, which in turn enhances expression and activity of Ecto-NOX1. Redox regulation of Ecto-NOX1 may be important to platelet recruitment and activation during inflammatory diseases.

The Effect of Glyphosate on the Reproduction of Estuarine Crabs: Neohelice granulata as a Study Model.

This review summarizes the bulk of evidence about the effect of glyphosate, both technical and formulated, on the ovarian maturation of Neohelice granulata female crabs, as well as the effects of glyphosate on sperm production in males of the same species. After long-term in vivo assays, made during the 3-month pre-reproductive period of this species, both formulated and technical glyphosate were able to produce a significant incidence of oocyte reabsorption in the ovary, together with a concomitant decreased of vitellogenin content, at concentrations ranging from 0.2 to 1 mg/L. Despite this, after 32-day in vivo assays, glyphosate stimulated oocyte growth, in terms of a higher percentage of vitellogenic oocytes, suggesting that glyphosate could be acting as an endocrine disruptor. In vitro assays made with isolated ovarian pieces showed a decrease of vitellogenin content, in correlation with lower protein synthesis, although some advance in maturation was observed in the histological analysis. In male crabs exposed in vivo to both technical and formulated glyphosate at 1 mg/L, several reproductive imbalances were noted, such as a significant decrease of the sperm count, abnormal spermatophores, and possible disrupting effects of glyphosate on the androgenic gland.

Expression of the endocannabinoid system in the bi-potential HEL cell line: commitment to the megakaryoblastic lineage by 2-arachidonoylglycerol.

The role of the endocannabinoid system in haematopoietic cells is not completely understood. We investigated whether human erythroleukemia (HEL) cells were able to bind, metabolise and transport the main endocannabinoids, anandamide (AEA) and 2-arachidonoylglycerol (2-AG). We also investigated whether AEA or 2-AG could modulate HEL differentiation. Although able to internalise both endocannabinoids, HEL cells had the machinery to metabolise 2-AG only, since they were devoid of the enzymes needed to synthesise and degrade AEA. Nonetheless, the intracellular transport of exogenous AEA might be required to activate the vanilloid receptors, with yet unknown implications for vascular biology. On the contrary, 2-AG appeared to play a role in lineage determination. Indeed, 2-AG itself drove HEL cells towards megakaryocytic differentiation, as it enhanced expression of beta3 integrin subunit, a megakaryocyte/platelet surface antigen, and glycoprotein VI, a late marker of megakaryocytes; in parallel, it reduced the amount of messenger RNA encoding for glycophorin A, a marker of erythroid phenotype. All these effects were mediated by activation of CB(2) cannabinoid receptors that triggered an extracellular signal-regulated kinase-dependent signalling cascade. In addition, classical inducers of megakaryocyte differentiation reduced 2-AG synthesis (although they did not affect the binding efficiency of CB(2) receptors), suggesting that levels of this endocannabinoid may be critical for committing HEL cells towards the megakaryocytic lineage.

The plasma membrane redox system in human platelet functions and platelet-leukocyte interactions.

The plasma membrane electron transport is crucial for blood coagulation and thrombosis, since reactive oxygen species and thiol changes, generated by plasma membrane redox reactions, modulate activation of platelets, as well as their interaction with leukocytes. Several antioxidants are linked to this system; thus, platelets are also able to counterbalance radical production and to regulate thrombus growth. Aim of this review is to give an update on the plasma membrane redox system in platelets, as well as on its role in platelet functions and leukocyte-platelet cross-talk.

Origanum vulgare induces apoptosis in human colon cancer caco2 cells.

Oregano spice is widely used in the Mediterranean diet, which is associated with a low risk for colon cancer. Although the medicinal benefits of oregano, such as the anti-inflammatory and antimicrobial activities, are well known; nonetheless, only few data are available on its effect in cancer prevention, especially concerning the mechanism of action. Here, we investigated the effect of Origanum vulgare ethanolic extracts on redox balance, cell proliferation, and cell death in colon adenocarcinoma Caco2 cells. Oregano extract leads to growth arrest and cell death in a dose- and time-dependent manner. Changes in glutathione content, as well as the increase in its oxidized form, may be involved in oregano-triggered death. Both extrinsic and intrinsic apoptotic pathways appear to be activated by spice extract. Our findings suggest that oregano amounts found in the Mediterranean diet can exert proapoptotic effects, which are selective for cancer cells. Moreover, whole extract, instead of a specific component, can be responsible for the observed cytotoxic effects.

Ovarian growth impairment after chronic exposure to Roundup Ultramax® in the estuarine crab Neohelice granulata.

Adult females of the estuarine crab Neohelice granulata were exposed to the glyphosate formulation Roundup Ultramax® during the entire 3-month pre-reproductive period. At the end of the assay, a significant higher increment of glycemia was noted at both glyphosate concentrations assayed (0.01 and 0.2 mg/L, acid equivalent). Although no differences were observed in the gonadosomatic index, a significantly higher proportion of reabsorbed vitellogenic oocyte was observed at the highest glyphosate concentration, together with a significant decrease of vitellogenin content in the ovary. In addition, some in vitro assays were carried out by co-incubating small pieces of ovary with or without the addition of Roundup; at both concentrations tested (same as those used in vivo), a decrease in the ovarian vitellogenin content was observed, whereas the ovarian protein synthesis was significantly inhibited by glyphosate at 0.2 mg/L in the Roundup formulation used.

Translational control of the ascorbic acid transporter SVCT2 in human platelets.

Reactive oxygen species (ROS) and redox state have emerged as physiological mediators, controlling blood coagulation and thrombosis. The redox balance is obviously linked to the presence of antioxidants; in particular, vitamin C appears to be a key modulator of platelet oxidative state, since these cells physiologically accumulate ascorbic acid and, moreover, platelet ascorbate plays a role during aggregation. Here, we showed that platelets could compensate for fluctuations in ascorbate levels by modulating the expression of the Na+-dependent transporter SVCT2. Furthermore, the use of anucleated cells demonstrated, for the first time, that SVCT2 expression could be regulated at the translational level. The control of ascorbic acid uptake, through regulation of its carrier, was not only related to substrate availability, but it also occurred during platelet activation, which was accompanied by vitamin C deprivation and alteration in the redox state. Finally, we showed that changes in intracellular ascorbic acid content had physiological relevance, since they modulate the surface sulfhydryl content and the thrombus viscoelastic properties. Beside its role during aggregation, vitamin C may also have important effects during postaggregatory events.

Cellular and biochemical parameters of exercise-induced oxidative stress: relationship with training levels.

To better clarify the relationship between physical activity and oxidative stress, we determined the effects of a maximal test in 18 young subjects with different training levels (six professional Athletes and 12 non-agonists (NA)). Redox homeostasis (total antioxidant activity (TAS), vitamin C and glutathione (GSH)), oxidative damage (diene conjugation and hemolysis), lymphocyte cell death and repair systems (apoptosis, micronuclei and Hsp70 expression) were evaluated. We found that agonistic training led to a chronic oxidative insult (high baseline values of oxidized glutathione (GSSG), micronuclei and hemolysis). On the contrary, NA with the lowest level of training frequency showed a well balanced profile at rest, but they were more susceptible to exercise-induced variations (GSSG/GSH and diene increased values), respect to the NA with an higher level of training. As almost all the parameters employed in this study showed inter-individual variations, the GSSG/GSH ratio remains the most sensitive and reliable marker of oxidative stress, accordingly with other data just reported in the literature.

Vitamin C homeostasis in skeletal muscle cells.

In skeletal muscle, vitamin C not only enhances carnitine biosynthesis but also protects cells against ROS generation induced by physical exercise. The ability to take up both ascorbic and dehydroascorbic acid from the extracellular environment, together with the ability to recycle the intracellular vitamin, maintains high cellular stores of ascorbate. In this study, we examined vitamin C transport and recycling, by using the mouse C2C12 and rat L6C5 muscle cell lines, which exhibit different sensitivity to oxidative stress and GSH metabolism. We found that: (1) both cell lines express SVCT2, whereas SVCT1 is expressed at very low levels only in proliferating L6C5 cells; furthermore L6C5 myoblasts are more efficient in ascorbic acid transport than C2C12 myoblasts; (2) C2C12 cells are more efficient in dehydroascorbic acid transport and ascorbyl free radical/dehydroascorbic acid reduction; (3) differentiation is paralleled by decreased ascorbic acid and dehydroascorbic acid transport and reduction and increased ascorbyl free radical reduction; (4) differentiated cells are more responsive to oxidative stress induced by glutathione depletion; indeed, myotubes showed increased SVCT2 expression and thioredoxin reductase-mediated dehydroascorbic acid reduction. From our data, SVCT2 and NADPH-thioredoxin-dependent DHA reduction appears to belong to an inducible system activated in response to oxidative stress.

Biological role of vitamin C in keratinocytes.

Epidemiological studies have suggested an association between vitamin C (and other antioxidant vitamins) and cancer risk. However, the mechanisms accounting for prevention have not been extensively investigated. In skin, vitamin C (ascorbic acid) exerts different biological roles, including photoprotective effects and participation in collagen synthesis. This paper reports new findings about additional functions of the vitamin. Vitamin C counteracts oxidative stress via transcriptional and post-translational mechanisms; this modulation may interfere with the activity of redox-sensitive transcription factors, commitment to differentiation or cell cycle arrest, and apoptosis in response to DNA damage. All of these vitamin C-mediated responses might be important in different cell types, allowing for the maintenance of body homeostasis.

Regulation of inflammation and proliferation of human bladder carcinoma cells by type-1 and type-2 cannabinoid receptors.

AIMS: Pro-inflammatory cytokines, growth and angiogenic factors released by leukocytes are involved in carcinogenesis and cancer progression, but they are also crucial for fighting tumour growth and spreading. We have previously demonstrated that endocannabinoids modulate cell-to-cell crosstalk during inflammation. Here, we investigated the inflammatory and tumourigenic properties of endocannabinoids in a human urinary bladder carcinoma cell line. MAIN METHODS: Endocannabinoid-treated ECV304 cells were checked for tumour necrosis factor (TNF)-α secretion (by ELISA assay) and surface exposure of selectins (by in situ ELISA and FACS analysis). ECV304/Jurkat T cell interaction was assessed by adhesion and live imaging experiments. Proliferation rate, cell death and cell cycle were determined by FACS analysis. KEY FINDINGS: By binding to type-1 (CB1) and type-2 (CB2) cannabinoid receptors, the endocannabinoid 2-arachidonoylglycerol (2-AG) exacerbates the pro-inflammatory status surrounding bladder carcinoma ECV304 cells, by: (i) enhancing TNF-α release, (ii) increasing surface exposure of P- and E-selectins, and (iii) allowing Jurkat T lymphocytes to adhere to treated cancer cells. We also found that the CB1 inverse agonist AM281, unlike 2-AG, decreases cancer proliferation by delaying cell cycle progression. SIGNIFICANCE: Our data suggest that 2-AG modulates the inflammatory milieu of cancer cells in vitro, while AM281 plays a more specific role in proliferation. Collectively, these findings suggest that CB receptors may play distinct roles in cancer biology, depending on the specific ligand employed. CONCLUSIONS: The in vivo assessment of the role of CB receptors in inflammation and cancer might be instrumental in broadening the understanding about bladder cancer biology.

Characterization of keratinocyte differentiation induced by ascorbic acid: protein kinase C involvement and vitamin C homeostasis.

Epidermal keratinocytes undergo differentiation in response to several stimuli to form the cornified envelope, a structure that contributes to the barrier function of skin. Although differentiation has been extensively analyzed, the precise role of vitamin C during this process is still not defined. Ascorbic acid, besides acting as a radical scavenger, has been shown to promote mesenchymal differentiation. In this study, we found that keratinocytes grown in ascorbate-supplemented medium developed a differentiated phenotype, as demonstrated by enhanced expression of marker genes and increase in cornified envelope content. The pro-differentiating effects of ascorbate were mediated by the protein-kinase-C-dependent induction of activating protein 1 DNA binding activity; indeed, down-modulation of protein kinase C activity abolished differentiation triggered by ascorbic acid. Although vitamin C appeared to regulate the same signaling pathway modulated by calcium, a classical in vitro inducer of epidermal differentiation, nonetheless terminally differentiated keratinocytes exhibited different ascorbate homeostasis and cellular antioxidant status. Indeed, we found that, unlike calcium, differentiation promoted by ascorbate was accompanied by (i) an enhanced ascorbate transport, due to overexpression of specific transporters, (ii) a great efficiency of dehydroascorbate uptake, and (iii) an increase in glutathione content with respect to proliferating cells. Ascorbic acid may be useful to promote epidermal differentiation, avoiding depletion of hydrophilic antioxidant stores.

Vitamin C recycling is enhanced in the adaptive response to leptin-induced oxidative stress in keratinocytes.

Leptin acts on energy metabolism and plays a role in skin repair and in the modulation of cellular redox balance as well. Here, we investigated the effects of leptin on the redox homeostasis in keratinocytes, by evaluating reactive oxygen species (ROS) generation, glutathione content, antioxidant enzymes, activating protein 1 (AP-1) activity, and expression of AP-1-dependent, differentiation-specific genes. We also evaluated the systems involved in the maintenance of a positive ascorbate/dehydroascorbate ratio, i.e., transport and recycling. Leptin altered the keratinocyte redox state, as evident by enhanced ROS generation, oxidized/reduced glutathione ratio, and AP-1 activity. Still, this phenomenon was temporary. Indeed, we found an adaptive response, as demonstrated by an early induction of catalase and a late induction of specific dehydroascorbate reductase activities. In particular, leptin-treated cells showed an increased ability to reduce dehydroascorbate, both in a NADH, lipoic acid- and in a NADPH, thioredoxin-dependent manner. Our results show that leptin may induce adaptation to oxidative stress in skin, leading to an improved vitamin C homeostasis.

Nuclear factor kappaB and activating protein 1 are involved in differentiation-related resistance to oxidative stress in skeletal muscle cells.

Skeletal muscle cells are continuously exposed to oxidative stress. Thus, they compensate environmental challenges by increasing adaptive responses, characterized by activating protein 1 (AP-1)- and nuclear factor kappaB (NF-kappaB)-mediated transcriptional upregulation of endogenous enzymatic and nonenzymatic antioxidants. We investigated the crosstalk of molecules involved in redox signaling in muscle cells, by using the rat L6C5 and mouse C2C12 cell lines, which represent a useful experimental model for studying muscle metabolism. We analyzed specific antioxidant systems, including glutathione, thioredoxin reductase, and antioxidant enzymes, and the redox-sensitive transcription factors AP-1 and NF-kappaB, in both myoblasts and myotubes. We found that the high levels of NF-kappaB DNA binding activity and thioredoxin reductase, together with inhibitory AP-1 complexes, allowed increased expression of antioxidant enzymes and survival of C2C12 cells after oxidant exposure. On the contrary, L6C5 myoblasts had a sensitive phenotype, correlated with lower levels of thioredoxin reductase, catalase, and NF-kappaB activity and higher levels of GSSG and activating AP-1 complexes. Interestingly, this cell line acquired an apoptosis-resistant phenotype, accompanied by drastic changes in the oxidant/antioxidant balance, when induced to differentiate. In conclusion, the two cell lines, although similar in terms of growth and differentiation, displayed significant heterogeneity in terms of redox homeostasis.

Effects of glyphosate on egg incubation, larvae hatching, and ovarian rematuration in the estuarine crab Neohelice granulata.

Ovigerous females of the estuarine crab (Neohelice granulate) were exposed to both pure glyphosate (2.5 mg/L and 5 mg/L) and a glyphosate formulation (Roundup Ultramax, containing glyphosate at 2.5 mg/L acid equivalent). At the end of the egg incubation period, a significant reduction in the number of hatched larvae was seen as a result of Roundup exposure. Additionally, several larvae abnormalities were seen in both pure glyphosate (2.5 mg/L) and Roundup treatments, such as hydropsy and hypopigmented eyes, and atrophied eyes were observed in the Roundup treatment. To evaluate the effect of the herbicide on ovarian rematuration, females remained exposed for 32 d. Pure glyphosate at 2.5 mg/L stimulated ovarian maturation over control levels, mainly in terms of a higher gonadosomatic index and a higher percentage of vitellogenic oocytes. A plausible hypothesis to be tested in further experiments is that exposure to glyphosate disrupts the hormonal system controlling reproduction.