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Effects of exposure of mytilus galloprovincialis to ni(ii), cu(ii) and cd(ii) on accumulation and on glutathione s-transferase expression level on gonads and gills
No full texthsp70 AS New Cadmium Bioaccumulation Marker to prevent the risks of Mussels Consumption in Human Nutrition
No full textThe consumption of seafood has increased in recent years, especially in coastal
regions. The consumption of mussels provides proteins, essential minerals and vitamins,
and thus, some protection from certain diseases but the risks and benefits of their
consumption are still hard to assess because of the metals bioaccumulated from the
marine environment, with their toxicity. Mussels accumulate a wide range of metals,
included cadmium, in their soft tissue. Cadmium is a heavy metal particularly hazardous
for human health and is an important pollutant in estuarine and coastal environments.
Thus, the determination of the concentrations of cadmium in mussels is essential because
of their usage as seafood and the potential adverse effects of their consumption on
human health. In order to identify a quick cadmium bioaccumulation marker usable in
monitoring programs, we analyzed the metal content in Mytilus galloprovincialis gill
tissues and its relationship with hsp70 expression levels after a laboratory exposure for
24 h to 1,5; 5 and 10 μM CdCl2 in artificial sea water. Inductively coupled plasma-mass
spectrometry showed that cadmium content increased in gills tissues in an exposure
dose-dependent fashion. RT-qPCR, showed that Cd exposure induced hsp70 increase
resulting in 3,1;10 and 12 fold at 1,5; 5, 10 μM, respectively in comparison with unexposed
mussels. Finally, hsp70 expression levels correlated with the amount of bioaccumulated
cadmium in gill tissue, indicating hsp70 as a potential marker, even if not univocally, of
significative cadmium bioaccumulation usable in environmental monitoring programs
and for seafood safety
Effects of exposure of mytilus galloprovincialis to ni(ii), cu(ii) and cd(ii) on accumulation and on glutathione s-transferase expression level on gonads and gills
No full textHydroxytyrosol decreases phosphatidylserine exposure and inhibits suicidal death induced by lysophosphatidic acid in human erythrocytes
No full textBackground/Aims: Lysophosphatidic acid (LPA) is a phospholipid signal molecule that regulates many cellular processes both physiological and pathological. Moreover, its high plasma concentrations are toxic for several cellular types, including erythrocytes (RBC), as it acts as a pro-thrombotic and pro-atherogenic agent. It is therefore essential to explore the potential protective role of nutrition in protecting cells from the possible toxic effects of high plasma concentrations of LPA by testing bioactive nutrients. In particular, our focus was on hydroxytyrosol (HT), a phenolic antioxidant occurring naturally in virgin olive oil, investigating its possible protective effect in preventing LPA-induced programmed cell death (eryptosis) in human RBC. Methods: Intact RBC were incubated in the presence of 2.5 μM LPA and increasing concentrations of HT. Phosphatidylserine (PS) exposure with cell shrinkage, influx of extracellular calcium (Ca2+), adenosine triphosphate (ATP) and glutathione levels were measured by FACS analysis. In addition, confocal laser scanning microscopy was used to determine RBC morphological alterations, as well as microvesicle formation. Results: Our study confirms that LPA-induced eryptosis is characterized by PS exposure at the cell surface, with cell shrinkage and ATP and glutathione depletion; (Ca2+) influx is also a key event that triggers eryptosis. Here we report for the first time that cell co-incubation with LPA and in quantities as low as 0.1 μM HT causes a significant decrease in PS-exposing RBC, in addition to providing significant protection from the decrease in cell volume. Moreover, treatment of RBC with HT counters the influx of extracellular Ca2+ and completely restores ATP and glutathione content at 1 μM. Finally, under the same experimental conditions, HT exerts a protective effect on RBC morphological changes and microvescicle release, completely restoring the typical biconcave shape at 1 μM. Conclusion: Taken together, the findings reported in this paper point to a novel biological effect for HT in preventing programmed suicidal death in anucleated cells and indicate that prevention from LPA toxic effects may represent an additional mechanism responsible for the health-promoting effect of this dietary phenol which has been claimed, particularly related to cardiovascular diseases
Morphological, Gene, and Hormonal Changes in Gonads and In-Creased Micrococcal Nuclease Accessibility of Sperm Chromatin Induced by Mercury
Full text linkMercury is one of the most dangerous environmental pollutants. In this work, we analysed the effects of exposure of Mytilus galloprovincialis to 1, 10 and 100 pM HgCl2 for 24 h on the gonadal morphology and on the expression level of three stress genes: mt10, hsp70 and πgst. In this tissue we also evaluated the level of steroidogenic enzymes 3β-HSD and 17β-HSD and the expression of PL protein genes. Finally, we determined difference in sperm chromatin accessibility to micrococcal nuclease. We found alterations in gonadal morphology especially after exposure to 10 and 100 pM HgCl2 and hypo-expression of the three stress genes, particularly for hsp70. Furthermore, decreased labelling with both 3β-HSD and 17β-HSD antibodies was observed following exposure to 1 and 10 pM HgCl2 and complete absence at 100 pM HgCl2 exposure. Gonads of mussels exposed to all HgCl2 doses showed decreased expression of PL protein genes especially for PLIII. Finally, micrococcal nuclease digestions showed that all doses of HgCl2 exposure resulted in increased sperm chromatin accessibility to this enzyme, indicative of improper sperm chromatin structure. All of these changes provide preliminary data of the potential toxicity of mercury on the reproductive health of this mussel
Olive Oil Phenols Prevent Mercury‐Induced Phosphatidylserine Exposure and Morphological Changes in Human Erythrocytes Regardless of Their Different Scavenging Activity
No full textPhosphatidylserine (PS) translocation to the external membrane leaflet represents a key mechanism in the pathophysiology of human erythrocytes (RBC) acting as an “eat me” signal for the removal of aged/stressed cells. Loss of physiological membrane asymmetry, however, can lead to adverse effects on the cardiovascular system, activating a prothrombotic activity. The data presented indicate that structurally related olive oil phenols prevent cell alterations induced in intact human RBC exposed to HgCl2 (5–40 μM) or Ca2+ ionophore (5 μM), as measured by hallmarks including PS exposure, reactive oxygen species generation, glutathione depletion and microvesicles formation. The protective effect is observed in a concentration range of 1–30 μM, hydroxytyrosol being the most effective; its in vivo metabolite homovanillic alcohol still retains the biological activity of its dietary precursor. Significant protection is also exerted by tyrosol, in spite of its weak scavenging activity, indicating that additional mechanisms are involved in the protective effect. When RBC alterations are mediated by an increase in intracellular calcium, the protective effect is observed at higher concentrations, indicating that the selected phenols mainly act on Ca2+‐ independent mechanisms, identified as protection of glutathione depletion. Our findings strengthen the nutritional relevance of olive oil bioactive compounds in the claimed health-promoting effects of the Mediterranean Diet
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
New insights into alterations in pl proteins affecting their binding to dna after exposure of mytilus galloprovincialis to mercury—a possible risk to sperm chromatin structure?
Full text linkMercury (Hg) is a highly toxic and widespread pollutant. We previously reported that the exposure of Mytilus galloprovincialis for 24 h to doses of HgCl2 similar to those found in seawater (range 1–100 pM) produced alterations in the properties of protamine-like (PL) proteins that rendered them unable to bind and protect DNA from oxidative damage. In the present work, to deepen our studies, we analyzed PL proteins by turbidimetry and fluorescence spectroscopy and performed salt-induced release analyses of these proteins from sperm nuclei after the exposure of mussels to HgCl2 at the same doses. Turbidity assays indicated that mercury, at these doses, induced PL protein aggre-gates, whereas fluorescence spectroscopy measurements showed mercury-induced conformational changes. Indeed, the mobility of the PLII band changed in sodium dodecyl sulphate-polyacrylamide gel electrophoresis, particularly after exposure to 10-pM HgCl2, confirming the mercury-induced structural rearrangement. Finally, exposure to HgCl2 at all doses produced alterations in PL-DNA binding, detectable by DNA absorption spectra after the PL protein addition and by a decreased release of PLII and PLIII from the sperm nuclei. In conclusion, in this paper, we reported Hg-induced PL protein alterations that could adversely affect mussel reproductive activity, providing an insight into the molecular mechanism of Hg-related infertility
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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