Carbon monoxide (CO) is an endogenously produced gasotransmitter with important biological functions: anti‐inflammation, anti‐apoptosis, vasomodulation and cell metabolism modulation. The most ...recognized cellular target for CO is the mitochondria. Physiological concentrations of CO generate mitochondrial reactive oxygen species (ROS), which are signalling molecules for CO‐induced pathways. Indeed, small amounts of ROS promote cytoprotection by a preconditioning effect. Furthermore, CO prevents cell death by limiting mitochondrial membrane permeabilization, which inhibits the release of pro‐apoptotic factors into the cytosol; both events are ROS dependent. CO also increases the ability of mitochondria to take up Ca2+. Mitochondrial metabolism is modulated by CO, namely by increasing TCA cycle rate, oxidative phosphorylation and mitochondrial biogenesis, which, in turn, increases ATP production. CO's modulation of metabolism might be important for cellular response to diseases, namely cancer and ischaemic diseases. Finally, another cytoprotective role of CO involves the control of Ca2+ channels. By limiting the activity of T‐type and L‐type Ca2+ channels, CO prevents excitotoxicity‐induced cell death and modulates cell proliferation. Several questions concerning Ca2+ signalling, mitochondria and CO can be asked, for instance whether CO modulation of cell metabolism would be dependent on the mitochondrial Ca2+ uptake capacity, since small amounts of Ca2+ can increase mitochondrial metabolism. Whether CO controls Ca2+ communication between mitochondria and endoplasmic reticulum is another open field of research. In summary, CO emerges as a key gasotransmitter in the control of several cellular functions of mitochondria: metabolism, cell death and Ca2+ signalling.
Carbon monoxide action on cellular targets: facts and hypotheses. CO inhibits Ca2+ channels located in the cytoplasmic membrane, promoting cytoprotection. At the mitochondrial level, CO has beneficial effects in a ROS‐dependent manner: it decreases mitochondrial membrane permeabilization and consequently inhibits cell death, promotes mitochondrial metabolism and improves mitochondrial Ca2+ uptake ability. In the upper‐right panel, it is hypothesized that CO is involved in Ca2+ balance between ER and mitochondria and that CO modulates mitochondrial metabolism via Ca2+ signalling.
Perinatal hypoxia-ischemia is a major cause of acute mortality in newborns and cognitive and motor impairments in children. Cerebral hypoxia-ischemia leads to excitotoxicity and necrotic and ...apoptotic cell death, in which mitochondria play a major role. Increased resistance against major damage can be achieved by preconditioning triggered by subtle insults. CO, a toxic molecule that is also generated endogenously, may have a role in preconditioning as low doses can protect against inflammation and apoptosis. In this study, the role of CO-induced preconditioning on neurons was addressed in vitro and in vivo. The effect of 1 h of CO treatment on neuronal death (plasmatic membrane permeabilization and chromatin condensation) and bcl-2 expression was studied in cerebellar granule cells undergoing to glutamate-induced apoptosis. CO's role was studied in vivo in the Rice-Vannucci model of neonatal hypoxia-ischemia (common carotid artery ligature +75 min at 8% oxygen). Apoptotic cells, assessed by Nissl staining were counted with a stereological approach and cleaved caspase 3-positive profiles in the hippocampus were assessed. Apoptotic hallmarks were analyzed in hippocampal extracts by Western Blot. CO inhibited excitotoxicity-induced cell death and increased Bcl-2 mRNA in primary cultures of neurons. In vivo, CO prevented hypoxia-ischemia induced apoptosis in the hippocampus, limited cytochrome c released from mitochondria and reduced activation of caspase-3. Still, Bcl-2 protein levels were higher in hippocampus of CO pre-treated rat pups. Our results show that CO preconditioning elicits a molecular cascade that limits neuronal apoptosis. This could represent an innovative therapeutic strategy for high-risk cerebral hypoxia-ischemia patients, in particular neonates.
Guarana Paullinia cupana var. sorbilis (Mart.) Ducke is a species of great economic and social important in Brazil, as it is the only commercial guarana producer in the world. The vegetative ...propagation method indicated for the culture is stem cuttings, which aims at productivity, tolerance, and uniformity of clonal cultivars, because reproduction by seeds has slow germination and high genetic variability, which in traditional varieties is an undesirable factor. Genetic factors can interfere with the rooting capacity of the crop. Studies seek alternatives that can improve this condition and enhance the production system. Use of growth regulators, microorganisms that promote plant growth, variation of substrates and fertilization, have been strategies used. Preliminary tests on the rate of stem rooting and seed germination with the use of exogenous phytohormone did not demonstrate in relation to the non-application of these inducers. The use of rhizobacteria, which presents itself as a promising activity in many cultures, has not yet been demonstrated in the culture of guarana. On the other hand, the influence of different substrates on rooting has already shown consistent results as a function of rooting rate. Fertilizing the mother plants as recommended by the production system for the crop has proven to be an efficient procedure. There are still few studies aimed at improving the spread of guarana, demonstrating that new protocols need to be explored, or that the protocols already used are reviewed from another perspective.
The proapoptotic Bax protein induces cell death by acting on mitochondria. Bax binds to the permeability transition pore complex (PTPC), a composite proteaceous channel that is involved in the ...regulation of mitochondrial membrane permeability. Immunodepletion of Bax from PTPC or purification of PTPC from Bax-deficient mice yielded a PTPC that could not permeabilize membranes in response to atractyloside, a proapoptotic ligand of the adenine nucleotide translocator (ANT). Bax and ANT coimmunoprecipitated and interacted in the yeast two-hybrid system. Ectopic expression of Bax induced cell death in wild-type but not in ANT-deficient yeast. Recombinant Bax and purified ANT, but neither of them alone, efficiently formed atractyloside-responsive channels in artificial membranes. Hence, the proapoptotic molecule Bax and the constitutive mitochondrial protein ANT cooperate within the PTPC to increase mitochondrial membrane permeability and to trigger cell death.
•Simulated and experimental design for passive cooling in day and night times.•Multilayer selective cooling design based on Al/SiO2/SiNx/SiO2/TiO2/SiO2.•Optical properties and structure of SiNx, SiO2 ...and TiO2 is studied.
A multilayer passive radiative selective cooling coating based on Al/SiO2/SiNx/SiO2/TiO2/SiO2 prepared by dc magnetron sputtering is presented. The design was first theoretically optimized using the optical constants, refractive index and extinction coefficient, of thin single layers. The spectral optical constants in the wavelength range from 0.3 to 27 µm were calculated from the transmittance and reflectance data of thin single layers deposited on silicon and glass substrates. The samples were characterized by Scanning Electron Microscopy, X-ray diffraction, Fourier-transform Infrared Spectroscopy and UV–VIS–NIR spectroscopy. It is shown that the TiO2 layer presents a partially rutile phase polycrystalline structure and a higher refractive index than amorphous SiO2 and SiNx layers in the spectral range from 0.3 to 2.5 μm. The cooling device was deposited on copper substrates and a thin low-density polyethylene foil with high transmittance in the 8 to 13 µm spectral range was used as convection cover material. The device is characterized by both low reflectance (high emittance) in the sky atmospheric window (wavelength range from 8 to 13 µm) and high hemispherical reflectance elsewhere, allowing for temperature drops of average 7.4 °C at night-time in winter, which corresponds to a net cooling power of ~43 W m−2. Further, a temperature drop of 2.5 °C was obtained during winter daytime.
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► The biosorption of food dyes onto
Spirulina platensis was optimized. ► The effects of pH, stirring rate and contact time were verified. ► The best results were 400 and 1653
mg
g
−1. ...► Avrami kinetic model was the best to represent the biosorption experimental data. ►
S. platensis is an alternative biosorbent to food dyes removal.
The biosorption of food dyes acid blue 9 and FD&C red no. 40 onto
Spirulina platensis was studied. A full factorial design was used to analyze the effects of pH (2–4), stirring rate (50–400
rpm) and contact time (20–100
min) on biosorption capacity. In the best conditions, biosorption kinetics was analyzed and the experimental data were fitted with four kinetic models. The best conditions were: pH 2, 400
rpm and 100
min for acid blue 9, and pH 2, 225
rpm and 100
min for FD&C red no. 40. In these conditions, the biosorption capacities were 1653.0
mg
g
−1 for acid blue 9 and 400.3
mg
g
−1 for FD&C red no. 40. For both dyes, the Avrami kinetic model was the more appropriate to represent the experimental data. These results showed that the
S. platensis is a suitable biosorbent for removal of food dyes from aqueous solutions.
Background:
This study tested the hypothesis that the low-grade inflammation presented in patients with bipolar disorder (BD) is associated with expansion of activated T cells, and this activated ...state may be due to a lack of peripheral regulatory cells.
Methods:
Specifically, we investigated the distribution of monocytes and lymphocyte subsets, and investigated Th1/Th2/Th17 cytokines in plasma by flow cytometry. Twenty-one BD type I patients and 21 age- and sex-matched controls were recruited for this study.
Results:
BD patients had increased proportions of monocytes (CD14+). Regarding lymphocyte populations, BD patients presented reduced proportions of T cells (CD3+) and cytotoxic T cells (CD3+CD8+). BD patients also exhibited a higher percentage of activated T CD4+CD25+ cells, and a lower percentage of IL-10 expressing Treg cells.
Conclusions:
Our data shed some light into the underlying mechanisms involved with the chronic low-grade inflammatory profile described in BD patients.
Eosinophils are multifunctional leukocytes implicated in numerous inflammatory diseases. The present study was conducted to clarify the precise role of eosinophils in the development of colitis by ...using eosinophil-depleted mice and a novel chemokine-binding protein that neutralizes CCL11 action. Colitis was induced by administration of dextran sodium sulfate (DSS) to wild-type and eosinophil-deficient Δ dbl GATA-1 mice. Accumulation of eosinophils in the gut of mice given DSS paralleled worsening of clinical score and weight loss. In response to DSS, Δ dbl GATA-1 mice showed virtual absence of eosinophil recruitment, amelioration of clinical score, weight loss, and tissue destruction, and no lethality. There was a decrease in CXCL1 and CCL3 production and decreased neutrophil influx in the intestine of Δ dbl GATA-1 mice. Transfer of bone marrow cells from wild-type mice reconstituted disease manifestation in DSS-treated Δ dbl GATA-1 mice, and levels of CCL11 were increased after DSS treatment and localized to inflammatory cells. Treatment with the chemokine-binding protein evasin-4 at a dose that prevented the function of CCL11 greatly ameliorated clinical score, weight loss, overall tissue destruction, and death rates. In conclusion, the influx of eosinophils is critical for the induction of colitis by DSS. Treatment with a novel chemokine-binding protein decreased eosinophil influx and greatly ameliorated colitis, suggesting that strategies that interfere with the recruitment of eosinophils may be useful as therapy for colitis.
The adsorption of azobenzene FD&C Red No. 40 (C.I. 16035) from aqueous solutions by chitosan was studied through adsorption isotherms. The effects of pH (5.7, 6.6 and 7.5), particle size ranges (0.10
...±
0.02, 0.18
±
0.02 and 0.26
±
0.02
mm), deacetylation degree (42
±
5%, 64
±
3% and 84
±
3%) and temperature (25, 35 and 45
°C) were investigated. Langmuir, Freundlich and Redlich–Peterson (R–P) adsorption models were applied in order to describe the experimental isotherms and isotherm constants. Coefficients of determination (
R
2
>
0.95) and mean relative error (MRE
<
0.10) values showed that Langmuir and R–P models presented better fit with the experimental data. The maximum monolayer adsorption value has been found to be 529
mg
g
−1, at pH 6.6, temperature 35
°C, particle size range 0.10
±
0.02
mm, and deacetylation degree 84
±
3%.
Less than one percent of marine natural products characterized since 1963 have been obtained from the phylum Bryozoa which, therefore, still represents a huge reservoir for the discovery of bioactive ...metabolites with its ~6000 described species. The current review is designed to highlight how bryozoans use sophisticated chemical defenses against their numerous predators and competitors, and which can be harbored for medicinal uses. This review collates all currently available chemoecological data about bryozoans and lists potential applications/benefits for human health. The core of the current review relates to the potential of bryozoan metabolites in human diseases with particular attention to viral, brain, and parasitic diseases. It additionally weighs the pros and cons of total syntheses of some bryozoan metabolites versus the synthesis of non-natural analogues, and explores the hopes put into the development of biotechnological approaches to provide sustainable amounts of bryozoan metabolites without harming the natural environment.
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