Mitochondria are involved in a variety of cellular functions, including ATP production, amino acid and lipid biogenesis and breakdown, signalling and apoptosis. Mitochondrial dysfunction has been ...linked to neurodegenerative diseases, cancer and ageing. Although transcriptional mechanisms that regulate mitochondrial abundance are known, comparatively little is known about how mitochondrial function is regulated. Here we identify the metabolite stearic acid (C18:0) and human transferrin receptor 1 (TFR1; also known as TFRC) as mitochondrial regulators. We elucidate a signalling pathway whereby C18:0 stearoylates TFR1, thereby inhibiting its activation of JNK signalling. This leads to reduced ubiquitination of mitofusin via HUWE1, thereby promoting mitochondrial fusion and function. We find that animal cells are poised to respond to both increases and decreases in C18:0 levels, with increased C18:0 dietary intake boosting mitochondrial fusion in vivo. Intriguingly, dietary C18:0 supplementation can counteract the mitochondrial dysfunction caused by genetic defects such as loss of the Parkinson's disease genes Pink or Parkin in Drosophila. This work identifies the metabolite C18:0 as a signalling molecule regulating mitochondrial function in response to diet.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
In the present study, effects of cis‐9,10‐epoxystearic acid (ESA) generated by the thermal oxidation of oleic acid on HepG2 cells, including intracellular lipid accumulation, fatty acid composition, ...and lipid metabolism, were investigated. Our results revealed that ESA increased the number and size of cellular lipid droplets. Intracellular triacylglycerol and total cholesterol content demonstrated that ESA induced lipid accumulation in HepG2 cells in a dose‐ and time‐dependent manner. Results of fatty acid composition further indicated that ESA could lead to intracellular lipid accumulation. Our results also revealed that ESA may suppress the fatty acid oxidation in peroxisomes and mitochondria, including PPARα, Cpt1α, and Acox1, whereas the expression of genes involved in lipid synthesis, including Srebp‐1c and Scd1, was enhanced. These findings provide critical information on the effects of ESA on HepG2 cells, particularly lipid accumulation and metabolism, which is important for evaluating the biosafety of the oxidative product of oleic acid.
Practical Application
The administration of cis‐9,10‐epoxystearic acid to HepG2 cells could lead to disorder of lipid metabolism of cells by enhancing the intracellular lipid content, as well as suppressing the fatty acid oxidation in peroxisomes and mitochondria. These findings could provide information for the evaluation of the biosafety of the oxidative product of oleic acid.
•Fish oil-in-water Pickering emulsion stabilized by chitosan (CS)-stearic acid (SA) nanogels.•Mayonnaise enriched with fish oil emulsion stabilized by CS-SA nanogels.•Fish oil in emulsified form ...increased the oxidative stability of mayonnaise.•CS-SA nanogel incorporating clove essential oil increased elasticity of mayonnaise.
The aim of this study was to introduce Pickering emulsions stabilized by chitosan (CS)-stearic acid (SA) nanogels incoporating clove essential oil (CEO) as a new way to enrich mayonnaise with fish oil. Firstly, fish oil-in-water Pickering emulsion was prepared, which the most stability of emulsion was achived at 2 % (w/w) CS-SA nanogels and 60 % (w/w) fish oil. Then, the fish oil-in-water Pickering emulsions stabilized with 2 % CS-SA nanogels as well as 2 % CS-SA nanogels incorporating CEO were used in formulation of mayonnaise. The results showed that the use of fish oil in the form of emulsion stabilized with CS-SA nanogels increased the oxidative stability of mayonnaise. Moreover, rheological studies indicated that the use of CS-SA nanogels could increase the elasticity of mayonnaise, which higher elasticity was observed about mayonnaise containing CS-SA nanogels incorporating CEO. Overall, CS-SA nanogels incorporating CEO can be used for increasing gel-like structure of the fish-oil-enriched mayonnaise.
A novel hydrophobic stearic acid-Yb-PbO2 (SA-Yb-PbO2) electrode with high oxygen evolution overpotential and long service lifetime was successfully fabricated through electrodeposition approach. The ...characterization of SA-Yb-PbO2 electrode, including surface morphology, elemental components, hydrophobicity, and crystal lattice structure, were performed. The results indicated that stearic acid's adulteration could enhance oxygen evolution overpotential and increase active specific surface area and the amounts of active sites. Then, the hydrophobic electrodes were used as anodes for electrolysis of naproxen sodium. The SA-Yb-PbO2 electrode showed better performance on naproxen sodium degradation than Yb-PbO2 electrode, exhibiting higher removal efficiency, lower energy consumption and higher mineralization current efficiency. Furthermore, the adulteration of stearic acid could greatly promote the stability and reusability of the electrodes for naproxen sodium degradation. The enhancement of electrode performance and oxidation power was related to high oxygen evolution overpotential and strong generation capability of OH caused by electrode's hydrophobic surface. Moreover, the degradation pathway and corresponding byproducts of naproxen sodium were obtained by HPLC and HPLC/MS assay, which revealed that naproxen sodium could be effectively mineralized by hydrophobic SA-Yb-PbO2 anode. These results presented that the organic pollutant wastewater containing naproxen sodium could be effectively decontaminated by electrochemical approach using hydrophobic SA-Yb-PbO2 electrode as anode.
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•A novel SA-Yb-PbO2 electrode with hydrophobic property was fabricated by electrodeposition method.•Hydrophobic property improves the electrochemical activity and stability of PbO2.•Naproxen sodium can be completely removed using hydrophobic SA-Yb-PbO2 as anode.•The electrochemical degradation intermediates and pathway of naproxen sodium were proposed.
Oil spills lead to a substantial depletion of aquatic biodiversity. The mitigation of an oil spill can entail considerable financial outlays, give rise to consequential environmental impacts, and ...present formidable operational complexities. In this research, hollow hydroxyapatite particles with enhanced oil adsorption characteristics were prepared by surface modification with stearic acid. Peanut and vacuum pump oils were used to imitate oil spills and conduct adsorption tests. The 50% stearic acid-modified hydroxyapatite (Sa/HAP) adsorbent showed superior hydrophobic properties with respect to water contact angle data. Adsorption isotherm analysis revealed that the adsorption processes of peanut and vacuum pump oils matched well with the Sips isotherm model, with regression coefficients of 0.992 and 0.996, respectively. The oil adsorption by the modified hydroxyapatite (HAP) adsorbent was found to be 9.85 g·g−1 for peanut oil and 12.13 g·g−1 for vacuum pump oil. Furthermore, the adsorption kinetics performance was determined by chemical interaction, whereas the adsorption equilibrium capacities were 8.97 g·g−1 and 11.41 g·g−1, respectively. Recycling of the spent adsorbent was performed with toluene stripping. The synthesized oil-adsorbents were analyzed by SEM, FTIR, XRD, contact angle, and TGA analyses. Hence, the efficacy of the Sa/HAP material as a potential adsorbent for the purification of oil-contaminated water was established, attributed to its commendable oil adsorption capability.
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•Sa-modified HAP showed excellent hydrophobicity with a high-water contact angle.•Evaluated peanut and vacuum pump oils adsorption on Sa/HAP particles.•Sips model showed the best fit for Sa/HAP adsorption, with R2 values 0.992 and 0.996.•Temperature influences the peanut and vacuum pump oils adsorption.•Sa-modified HAP particles can be regenerated using the toluene stripping method.
A novel formulation based on nanostructured lipid carriers (NLCs) was developed to increase solubility and intestinal absorption of khellin. K-NLCs were prepared with stearic acid, hempseed oil, Brij ...S20, and Labrafil M 1944 CS, using the emulsification-ultrasonication method. Developed nanoparticles were chemically and physically characterized by liquid chromatography, light scattering techniques, and electron microscopy. The size, about 200 nm, was optimal for oral delivery, and the polydispersity index (around 0.26), indicated high sample homogeneity. Additionally, K-NLCs showed a spherical morphology without aggregation by microscopic analysis. The encapsulation efficiency of khellin was about 55%. In vitro release studies were carried out in media with different pH to mimic physiological conditions. K-NLCs were found to be physically stable in the simulated gastric and intestinal fluids, and they preserved about 70% of khellin after 6 h incubation. K-NLCs were also successfully lyophilized testing different lyoprotectants, and obtained freeze-dried K-NLCs demonstrated good shelf life over a month. Lastly, permeability studies on Caco-2 cells were performed to predict khellin passive diffusion across the intestinal epithelium, demonstrating that nanoparticles increased khellin permeability by more than two orders of magnitude. Accordingly, developed NLCs loaded with khellin represent a versatile formulation with good biopharmaceutical properties for oral administration, possibly enhancing khellin's bioavailability and therapeutic effects.
Severe agglomeration caused by high calcination temperature is a major challenge to the preparation of highly dispersed α-Al2O3. In this study, α-Al2O3 nanoparticles were prepared by stearic ...acid-assisted mechanochemical method. The mechanochemistry induced the conversion of ammonium aluminum carbonate hydroxide (AACH) to α-Al2O3 during the calcination process and significantly reduced the phase transition temperature of α-Al2O3. The sintering phenomenon between α-Al2O3 particles was reduced by constructing an organic protective layer on the AACH surface using stearic acid. The composition, structure, and morphology of the prepared powders were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric-differential scanning calorimetry (TG-DSC). Carbon produced by calcining stearic acid in the N2 atmosphere was distributed on the surface of the α-Al2O3 grains, which impeded the growth of the α-Al2O3 nanoparticles. The average size of the samples obtained was smaller, and the size distribution was narrower than that of the directly calcined AACH.
Preparation of α-Al2O3 nanoparticles by ball milling and stearic acid at low temperature. Display omitted
•Homogenous nanosized α-Al2O3 was synthesized by low temperature calcination AACH•The ball-milling reduces phase transition temperature from AACH to α-Al2O3•Stearic acid hinders the abnormal growth of α-Al2O3 grains at high temperature
The objective of the experiment was to determine the effects of supplemental saturated fatty acid (SFA) sources, lysophospholipids (LPL), and their interaction on production and nutrient ...digestibility in lactating dairy cows. The experiment was conducted with 48 cows in a randomized complete block design. Cows were blocked (total 12 blocks) by parity and days in milk and randomly assigned to 4 dietary treatments in each block (2 × 2 factorial arrangement), i.e., 2 sources of fat supplements, C16:0 (palmitic acid, PA)- or C18:0 (stearic acid, SA)-enriched fat, with or without LPL. The experiment was conducted for 6 wk to measure daily dry matter intake and milk yield and weekly milk composition. During the last week of the experiment, spot fecal and urine samples were collected to determine total-tract nutrient digestibility. Milk samples in the last week were also collected to analyze for milk fatty acid (FA) profile. All data were analyzed using the mixed procedure of SAS where block was used as a random effect and FA, LPL, and the interaction of FA by LPL were used as fixed effects. Week and interactions of week by FA or LPL were included for production measures. Different sources of SFA did not affect dry matter intake and milk yield. However, PA increased (39.7 vs. 36.8 kg) energy-corrected milk compared with SA due to increased milk fat yield. No effect of LPL on production measures was observed. Total-tract digestibilities of dry matter, organic matter, crude protein, and total FA were not different between PA and SA, but PA increased (41.4 vs. 38.8%) neutral detergent fiber digestibility compared with SA. Supplementation of LPL increased (64.7 vs. 60.5%) total FA digestibility, especially 18-carbon FA (74.1 vs. 68.2%). An interaction of SFA by LPL was found for 16-carbon FA digestibility. The PA diet increased the concentration of 16-carbon FA in milk fat and SA increased the concentration of preformed FA (≥18 carbons). Supplementation of LPL decreased the concentration of trans-10 C18:1. No difference in N utilization and excretion among treatments was observed. In conclusion, PA was more effective in improving milk fat yield of lactating cows compared with SA. Supplementation of LPL increased digestibility of total FA, especially 18-carbon FA but did not affect production.
A novel polymer, i.e. galactosylated O-carboxymethyl chitosan-graft-stearic acid (Gal-OCMC-g-SA) was synthesized for liver targeting delivery of doxorubicin. The chemical structure was characterized ...by FT-IR, 1H NMR and elemental analysis. Gal-OCMC-g-SA could self-assemble into nanoparticles with diameter of 160nm by probe sonication in aqueous medium and exhibited a low critical aggregation concentration of 0.047mg/mL. The DOX-loaded Gal-OCMC-g-SA (Gal-OCMC-g-SA/DOX) self-assembled nanoparticles were almost spherical in shape with an average diameter of less than 200nm and zeta potential of around −10mV. In vitro release revealed that the Gal-OCMC-g-SA/DOX nanoparticles exhibited a sustained and pH-dependent drug release manner. Furthermore, the hemolysis test demonstrated the good safety of Gal-OCMC-g-SA in blood-contacting applications. These results indicated that Gal-OCMC-g-SA/DOX nanoparticles were highly potential to be applied in cancer therapy.
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