4,043 research outputs found
Troposphere ozone as a source of oxidative stress in cutaneous tissues
No full textThis review presents troposphere ozone (O3) as a source of oxidative stress in cutaneous tissues. O3 may cause a disturbance of the barrier function, increase transepidermal water loss and provoke epidermal repair responses, as can be also seen after barrier perturbation. Depletion of O3 at stratospheric level leads to an increased exposure to UV radiation, well known source of skin cancer. Increased level of O3 at the ground level, together with increased UV exposure as a consequence of O3 depletion in stratosphere can have an additive effect on the development of skin pathologies
Cigarette Smoke Affects ABCAl Expression via Liver X Receptor Nuclear Translocation in Human Keratinocytes
No full textCutaneous tissue is the first barrier against outdoor insults. The outer most layer of the skin, the stratum corneum (SC), is formed by corneocytes embedded in a lipid matrix (cholesterol, ceramide and fatty acids). Therefore, the regulation of lipids and, in particular, of cholesterol homeostasis in the skin is of great importance. ABCA1 is a membrane transporter responsible for cholesterol efflux and plays a key role in maintaining cellular cholesterol levels. Among the many factors that have been associated with skin diseases, the environmental stressor cigarette smoke has been recently studied. In the present study, we demonstrate that ABCA1 expression in human cells (HaCaT) was increased (both mRNA and protein levels) after CS exposure. This effect was mediated by the inhibition of NFkB (aldehydes adducts formation) that allows the translocation of liver X receptor (LXR). These findings suggest that passive smoking may play a role in skin cholesterol levels and thus affect cutaneous tissues functions
Scavenger receptor class B type I: a multifunctional receptor
No full textThe scavenger receptor class B type I (SR-B1) plays an important role in meditating the uptake of HDL-derived cholesterol and cholesteryl ester in the liver and steroidogenic tissues. In addition to being ubiquitous, SR-B1 is a high-density lipoprotein (HDL) receptor in many tissues, though the mechanism by which SR-B1 does this is unclear. Other than its role as an HDL receptor, SR-B1 is also involved in pathogen recognition; its expression can be modulated by lipopolysaccharide and oxidative stress; and it plays a significant role in the uptake of lipid soluble vitamins, such as vitamin E and carotenoids. In this short review, we have summarized the biological aspects to which SR-B1 has been thus far associated
In vitro assessement of tariquidar toxicity towards vasculature
No full textBackground: The P-glycoprotein (P-gp) inhibitor tariquidar, intravenously administered, increases brain uptake of radiolabeled P-gp
substrates, commonly used to detect functional alterations of blood –
brain barrier pumps in PET imaging [1]. However, the doses that are
required — up to 4-fold higher than those already used in clinical trials
to reverse multidrug resistance — cause syncopal episodes and hypotension [2]. Therefore, we investigated the toxic hazard of these
doses towards the vasculature.
Methods: The effects of tariquidar on A7r5 and EA.hy926 cell
viability, on the mechanical activity of fresh and cultured rat aorta
rings, as well as on A7r5 CaV1.2 channel current (ICa1.2) were
analysed [3].
Results: In both A7r5 and EA.hy926 cells, tariquidar was generally
devoid of cytotoxic effects up to a concentration of 1 μM. However, at
10 μM, it caused apoptosis already after 24 h treatment. In endothelium-denuded aorta rings, 10 μM tariquidar relaxed contractions
induced by phenylephrine but not by high K+. The contractile activity
of rings cultured for 7 days was not affected by drug treatment.
Finally, tariquidar did not modify ICa1.2 intensity and kinetics.
Discussion: Tariquidar exerts both cytotoxic and acute vascular
effects at concentrations comparable to those employed in PET
imaging. This may limit its use as diagnostic tool.
Acknowledgements: This work was supported by the Italian Ministry
for Instruction, Universities and Research (Futuro in Ricerca 2012,
RBFR12SOQ1 to S. S.)
Effects of U373-MG astrocytoma cells conditioned medium on differentiated IMR-32 neuroblastoma cells subjected to hypoxia
No full textThe lost of Scavenger Receptor B1 by Cigarette Smoke Exposure in Keratinocytes is Driven by H202
No full textThe lost of Scavenger Receptor B1 by Cigarette Smoke
Exposure in Keratinocytes is Driven by H2O2
Giuseppe Valacchi
1
, Claudia Sticozzi
2
, Alessandra Pecorelli
3
, Giuseppe
Belmonte4
, Emanuela Maioli
5
, Beatrice Arezzini
3
, and Concetta Gardi
3
1
Dept. of Evolutionary Biology,
2
Dept. di Ingegneria Meccanica e
Strutturale,
3
Dept of Pathology,
4
Dept of Biomedical
Sciences,
5
Dept of Physiology, University of Siena
Scavenger Receptor B1 (SRB1), also known as HDL receptor, is
involved in cellular cholesterol uptake. Stratum corneoum (SC),
the outermost layer of the skin, is composed for more than 25%
by cholesterol. Several reports support the view that alteration of
SC lipids composition may be the cause of impaired barrier
function which gives rise to several skin diseases. for this reason
the regulation of the genes involved in cholesterol uptake is of
extreme significance for skin health. Being the first shield against
the outdoor insults, the skin is exposed to several noxious
substances and among these is cigarette smoke (CS) which has
been recently associated to various skin pathologies. Using
immunoblotting, immunoprecipitation, RT-PCR, and confocal
microscopy we have demonstrated that the translocation and the
consecutive lost of SRB1 in human keratinocytes after CS
exposure is driven by hydrogen peroxide (H2O2) which derives not
only from the CS gas phase but mainly from the activation of
cellular NADPH oxidase (NOX). This effect was reversed when
the cells were pretreated with NOX inhibitors, catalase, or
superoxide dismutase (SOD) inhibitor. Furthermore, CS caused
the formation of SRB1-aldheydes adducts (Acrolein and 4-
Hydroxynonenal) and the increased of its ubiquitination which is
the cause of SRB1 lost. in conclusion, exposure to CS, through
the production of H2O2, induced post-translational modifications of
SRB1 with the consequence lost of the receptor and this may
contribute to the skin physiology alteration
The Magic Velvet Bean of Mucuna pruriens
No full textMucuna pruriens (Fabaceae) is an established herbal drug used for the management of male infertility, nervous disorders, and also as an aphrodisiac. It has been shown that its seeds are potentially of substantial medicinal importance. The ancient Indian medical system, Ayurveda, traditionally used M. pruriens, even to treat such things as Parkinson's disease. M. pruriens has been shown to have anti-parkinson and neuroprotective effects, which may be related to its anti-oxidant activity. In addition, anti-oxidant activity of M. pruriens has been also demonstrated in vitro by its ability to scavenge DPPH radicals and reactive oxygen species. In this review the medicinal properties of M. pruriens are summarized, taking in consideration the studies that have used the seeds extracts and the leaves extracts
Claudia Rankine: An Evening with Claudia Rankine
No full textAn initiative of the National Endowment for the Arts in partnership with Arts Midwest, the NEA Big Read broadens our understanding of our world, our communities, and ourselves through the joy of sharing a good book. For NEA Big Read: Hampton Roads, that book is Citizen: An American Lyric.
NEA Big Read: Hampton Roads, the President\u27s Lecture Series, and the President\u27s Task Force on Inclusive Excellence invite you to a powerful evening with Claudia Rankine, the book\u27s author, hosted by Tim Seibles, Poet Laureate for the Commonwealth of Virginia, and opening with readings by local youth poets.
Claudia Rankine has written five collections of poetry, including Citizen: An American Lyric, which was selected for the National Endowment for the Arts\u27 Big Read, and two plays. She also has participated in several video collaborations and edited anthologies including The Racial Imaginary: Writers on Race in the Life of the Mind.
Rankine has received fellowships from the MacArthur and Guggenheim foundations. Citizen won several honors, including the National Book Critics Circle Award for Poetry, the PEN Open Book Award and the NAACP Image Award. Citizen also was the only poetry book to be a New York Times nonfiction bestseller. She is the Frederick Iseman Professor of Poetry at Yale University and chancellor of the Academy of American Poets
Skin damage mechanisms related to airborne particulate matter exposure
No full textEpidemiological studies suggest a correlation between increased airborne particulate matter (PM) and adverse health effects. The mechanisms of PM-health effects are believed to involve oxidative stress and inflammation. To evaluate the ability of PM promoting skin tissue damage, one of the main organs exposed to outdoor pollutants, we analyzed the effect of concentrated ambient particles (CAPs) in a reconstructed human epidermis (RHE) model. RHE tissues were exposed to 25 or 100 μg/ml CAPs for 24 or 48 h. Data showed that RHE seems to be more susceptible to CAPs-induced toxicity after 48 h exposure than after 24 h. We found a local reactive O2 species (ROS) production increase generated from metals present on the particle, which contributes to lipids oxidation. Furthermore, as a consequence of altered redox status, NFkB nucleus translocation was increase upon CAPs exposure, as well as cyclooxygenase 2 and cytochrome P450 levels, which may be involved in the inflammatory response initiated by PM. CAPs also triggered an apoptotic process in skin. Surprisingly, by transition electron microscopy analysis we showed that CAPs were able to penetrate skin tissues. These findings contribute to the understanding of the cutaneous pathophysiological mechanisms initiated by CAPs exposure, where oxidative stress and inflammation may play predominant roles.Fil: Magnani, Natalia Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Muresan, Ximena M.. Universita Di Ferrara; ItaliaFil: Belmonte, Giuseppe. Universita Di Ferrara; ItaliaFil: Cervellati, Franco. Universita Di Ferrara; ItaliaFil: Sticozzi, Claudia. Universita Di Ferrara; ItaliaFil: Pecorelli, Alessandra. Universita Di Ferrara; ItaliaFil: Miracco, Clelia. Università Degli Studi Di Siena; ItaliaFil: Marchini, Timoteo Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Evelson, Pablo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Valacchi, Giuseppe. Universita Di Ferrara; Itali
Cutaneous responses to environmental stressors
No full textLiving organisms are continuously exposed to environmental pollutants. Because of its critical location, the skin is a major interface between the body and the environment and provides a biological barrier against an array of chemical and physical environmental pollutants. The skin can be defined as our first defense against the environment because of its constant exposure to oxidants, including ultraviolet (UV) radiation and other environmental pollutants such as diesel fuel exhaust, cigarette smoke (CS), halogenated hydrocarbons, heavy metals, and ozone (O3). The exposure to environmental pro-oxidant agents leads to the formation of reactive oxygen species (ROS) and the generation of bioactive molecules that can damage skin cells. This short review provides an overview of the effects and mechanisms of action of CS, O3, and UV on cutanous tissues. © 2012 New York Academy of Sciences
- …
