Methionine–choline-deficient (MCD) diet is a widely used dietary model of non-alcoholic steatohepatitis (NASH) in rodents. However, the contribution of adipose tissue to MCD-induced steatosis, and ...inflammation as features of NASH are not fully understood. The goal of this study was to elucidate the role of adipose tissue fatty acid (FA) metabolism, adipogenesis, lipolysis, inflammation and subsequent changes in FA profiles in serum and liver in the pathogenesis of steatohepatitis. We therefore fed ob/ob mice with control or MCD diet for 5weeks. MCD-feeding increased adipose triglyceride lipase and hormone sensitive lipase activities in all adipose depots which may be attributed to increased systemic FGF21 levels. The highest lipase enzyme activity was exhibited by visceral WAT. Non-esterified fatty acid (NEFA)-18:2n6 was the predominantly elevated FA species in serum and liver of MCD-fed ob/ob mice, while overall serum total fatty acid (TFA) composition was reduced. In contrast, an overall increase of all FA species from TFA pool was found in liver, reflecting the combined effects of increased FA flux to liver, decreased FA oxidation and decrease in lipase activity in liver. NAFLD activity score was increased in liver, while WAT showed no changes and BAT showed even reduced inflammation. Conclusion: This study demonstrates a key role for adipose tissue lipases in the pathogenesis of NASH and provides a comprehensive lipidomic profiling of NEFA and TFA homeostasis in serum and liver. Our findings provide novel mechanistic insights for the role of WAT in progression of MCD-induced liver injury.
•MCD model of NASH increases lipase activity in WAT as a critical determinant of hepatic FA flux and lipotoxicity.•The maximal increase of ATGL and HSL activity is in visceral WAT.•Increased lipase activity may be due to enhanced FGF21 signaling.•NEFA-18:2n6 is preferentially increased in serum and liver due to lipolysis in WAT.•MCD diet enhances the activity of BAT and diminishes its inflammatory markers.
Hepatic inflammation is a key feature of progressive liver disease. Alterations of fatty acid (FA) metabolism and signaling may play an important role in the pathogenesis of nonalcoholic fatty liver ...disease (NAFLD) and its progression to nonalcoholic steatohepatitis (NASH). Moreover, FAs activate peroxisome proliferator‐activated receptor α (PPARα) as a key transcriptional regulator of hepatic FA metabolism and inflammation. Since adipose triglyceride lipase (ATGL/PNPLA2) is the key enzyme for intracellular hydrolysis of stored triglycerides and determines FA signaling through PPARα, we explored the role of ATGL in hepatic inflammation in mouse models of NASH and endotoxemia. Mice lacking ATGL or hormone‐sensitive lipase (HSL) were challenged with a methionine‐choline‐deficient (MCD) diet as a nutritional model of NASH or lipopolysaccharide (LPS) as a model of acute hepatic inflammation. We further tested whether a PPARα agonist (fenofibrate) treatment improves the hepatic phenotype in MCD‐ or LPS‐challenged ATGL‐knockout (KO) mice. MCD‐fed ATGL‐KO mice, although partially protected from peripheral lipolysis, showed exacerbated hepatic steatosis and inflammation. Moreover, ATGL‐KO mice challenged by LPS showed enhanced hepatic inflammation, increased mortality, and torpor, findings which were attributed to impaired PPARα DNA binding activity due to reduced FABP1 protein levels, resulting in impaired nuclear FA import. Notably, liganding PPARα through fenofibrate attenuated hepatic inflammation in both MCD‐fed and LPS‐treated ATGL‐KO mice. In contrast, mice lacking HSL had a phenotype similar to the WT mice on MCD and LPS challenge. Conclusion: These findings unravel a novel protective role of ATGL against hepatic inflammation which could have important implications for metabolic and inflammatory liver diseases. (Hepatology 2014;59:858–869)
Gelation is one of the functional properties of protein, which can be controlled by pH and ionic strength. However, kowledge related to gelation properties of emerging plant proteins is still ...limited. In this paper, the solubility, the thermal behaviour and gelation behaviour of pea protein were analysed. Gels were analysed rheologically measuring the elastic modulus G′25°C, the ratio of G′25°C to G′95°C, and dependence on frequency and amplitude. In addition, the stabilizing protein interactions within the gel were analysed. The stiffest gels were obtained at pH 4.5 at 0.6 M NaCl. The high G′25°C and low tan δ value indicate the inclusion of active fillers, which is proposed to be insoluble protein. Salt addition at acidic pH could protect the protein from acid denaturation leading to a low heat denaturation at 62 °C–68 °C compared to heat denaturation at neutral pH. Addition of salt at pH 3 also led to a stiffer gel with a lower G′25 °C/G′95°C ratio, which indicates more hydrophobic and covalent interactions. An increase in ionic strength at pH 7 and pH 9 led to an increase of denaturation temperature above gelation temperature and an increase of electrostatic interactions. At pH 9 at ionic strenghts of 0.9 M NaCl and 1.5 M NaCl the frequency sweep showed that an entangled solution was formed, instead of a gel. It was observed that pea protein gelation were more influenced by the ionic strength at low pH values compared to neutral or alkaline pH.
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•Ionic strength has a minor effect on gelation at neutral and alkaline pH and a major effect at acidic pH.•Solubility impacts stiffness of pea protein gels.•Gels at pH 9 and high ionic strength resemble rather entangled solutions than a gel.•Stabilizing protein interaction are non-covalent and dependent on pH and ionic strength.
Biomimetic nanocrystalline apatites analogous to bone mineral can be prepared using soft chemistry. Due to their high similarity to bone apatite, as opposed to stoichiometric hydroxyapatite for ...example, they now represent an appealing class of compounds to produce bioactive ceramics for which drug delivery and ion exchange abilities have been described extensively. However, immersion in aqueous media of dried non-carbonated biomimetic apatite crystals may generate an acidification event, which is often disregarded and not been clarified to-date. Yet, this acidification process could limit their further development if it is not understood and overcome if necessary. This may, for example, alter biological test outcomes, during their evaluation as bone repair materials, due to potentially deleterious effects of the acidic environment on cells, especially in in vitro static conditions. In this study, we explore the origins of this acidification phenomenon based on complementary experimental data and we point out the central role of the hydrated ionic layer present on apatite nanocrystals. We then propose a practical strategy to circumvent this acidification effect using an adequate post-precipitation equilibration step that was optimized. Using this enutralization protocol, we then showed the possibility of performing (micro)biological assessments on such compounds and provide an illustration with the examples of post-equilibrated Cu
- and Ag
-doped nanocrystalline apatites. We demonstrate their non-cytotoxicity to osteoblast cells and their antibacterial features as tested versus five major pathogens involved in bone infections, therefore pointing to their relevance in the field of antibacterial bone substitutes. The preliminary in vivo implantation of a relevant sample in a rat's calvarial defect confirmed its biocompatibility and the absence of adverse reaction. Understanding and eliminating this technical barrier should help promoting biomimetic apatites as a genuine new class of biomaterial-producing compounds for bone regeneration applications, e.g., with antibacterial features, far from being solely considered as "laboratory curiosities".
OBJECTIVE:-- Diabetes is characterized by marked postprandial endothelial dysfunction induced by hyperglycemia, hypertriglyceridemia, advanced glycation end products (AGEs), and dicarbonyls (e.g., ...methylglyoxal MG). In vitro hyperglycemia-induced MG formation and endothelial dysfunction could be blocked by benfotiamine, but in vivo effects of benfotiamine on postprandial endothelial dysfunction and MG synthesis have not been investigated in humans until now. RESEARCH DESIGN AND METHODS-- Thirteen people with type 2 diabetes were given a heat-processed test meal with a high AGE content (HAGE; 15.100 AGE kU, 580 kcal, 54 g protein, 17 g lipids, and 48 g carbohydrates) before and after a 3-day therapy with benfotiamine (1,050 mg/day). Macrovascular flow-mediated dilatation (FMD) and microvascular reactive hyperemia, along with serum markers of endothelial disfunction (E-selectin, vascular cell adhesion molecule-1, and intracellular adhesion molecule-1), oxidative stress, AGE, and MG were measured during both test meal days after an overnight fast and then at 2, 4, and 6 h postprandially. RESULTS:-- The HAGE induced a maximum reactive hyperemia decrease of -60.0% after 2 h and a maximum FMD impairment of -35.1% after 4 h, without affecting endothelium-independent vasodilatation. The effects of HAGE on both FMD and reactive hyperemia were completely prevented by benfotiamine. Serum markers of endothelial dysfunction and oxidative stress, as well as AGE, increased after HAGE. These effects were significantly reduced by benfotiamine. CONCLUSIONS:-- Our study confirms micro- and macrovascular endothelial dysfunction accompanied by increased oxidative stress following a real-life, heat-processed, AGE-rich meal in individuals with type 2 diabetes and suggests benfotiamine as a potential treatment.
To investigate the efficacy and safety of two different budesonide formulations (effervescent tablet for orodispersible use (BET) and viscous suspension (BVS)) with different daily dosages for ...short-term treatment of eosinophilic oesophagitis (EoE).
Adults with active EoE (n=76) randomly received 14 days' treatment with either BET 2×1 mg/day (BET1, n=19) or BET 2×2 mg/day (BET2, n=19), or BVS 2×5 mL (0.4 mg/mL)/day (BVS, n=19) or placebo (n=19) in a double-blind, double-dummy fashion, with a 2-week follow-up. Primary end point was histological remission (mean of <16 eosinophils/mm(2 )hpf). Secondary end points included endoscopy score, dysphagia score, drug safety and patient's preference for drug formulation.
Histological remission occurred in 100%, 94.7% and 94.7% of budesonide (BET1, BET2, BVS, respectively) and in 0% of placebo recipients (p<0.0001). The improvement in total endoscopic intensity score was significantly higher in the three budesonide groups compared with placebo. Dysphagia improved in all groups at the end of treatment; however, improvement of dysphagia persisted only in those treated with BET1 (p=0.0196 vs placebo). There were no serious adverse events. Local fungal infection (stained fungi) occurred in two patients of each budesonide group (10.5%). The effervescent tablet was preferred by 80% of patients.
BET or BVS was highly effective and safe for short-term treatment of EoE. The 1 mg (twice daily) dosage was equally effective as the 2 mg twice daily dosage. The majority of patients preferred the effervescent tablet formulation.
NCT02280616; EudraCT number, 2009-016692-29.
•Sorbitol-plasticized films were stiffer than glycerol-plasticized films.•Moisture transmission was higher for glycerol containing films than containing sorbitol.•For glycerol-plasticized films, a ...strong decline of the moisture transmission at 10 % (w/w) beeswax addition could be identified.•Antioxidant potential of quercetin entrapped in sodium caseinate-based emulsion films has been demonstrated.•The effects of the lipid concentration were less apparent compared to the plasticizer effects.
The objective of this study was to examine the effects of the plasticizer type (sorbitol or glycerol) and lipid concentration (oleic acid or oleic acid-beeswax mixtures) on sodium caseinate (NaCas)-based films and to investigate how, and to which extent, these parameters are affecting the technofunctional properties of NaCas-based films. Additionally, we intended to demonstrate the antioxidant potential of quercetin as a component of the described formulations. Films prepared from the different composed emulsions were characterized in terms of selected packaging-relevant properties. The results showed that the type of plasticizer and the lipid concentration had significant effect on the technofunctional properties of NaCas-based films. Contact angle measurement and evaluation of the SFE revealed rather hydrophilic than hydrophobic surfaces. Determination of the WVTR showed a significant influence (p≤0.05) of the type of plasticizer towards WVTR. WVTR was clearly decreased for sorbitol-plasticized films. On the contrary, the influence of the lipid concentration was also significant (p≤0.05), but not as clear as the plasticizer effect. However, at 10% (w/w) beeswax (BW) addition, there was a sharp drop in WVTR visible for glycerol-plasticized films. Measurement of the OP did not yield as clear results as suggested in preliminary test series. Although, we did not conduct systematic studies regarding the effect of the antioxidant towards the OP we showed the antioxidant potential of the described compositions. Results for the mechanical performance showed a significant influence (p≤0.05) of the type of plasticizer and lipid concentration. YM and TS values were clearly higher for sorbitol-plasticized films whereas E% values were lower for sorbitol-plasticized films. Regarding the effect of the lipid concentration on the mechanical performance, no apparently visible trend could be identified. Light transmittance measurement revealed that in terms of UV-absorptivity at wavelengths between 300 nm and 400 nm, the incorporation of quercetin led to promising barrier properties against UV-light.
Lactate is an important metabolic intermediate released by skeletal muscle and other organs including the adipose tissue, which converts glucose into lactate under the influence of insulin. Here we ...show that lactate activates the G protein-coupled receptor GPR81, which is expressed in adipocytes and mediates antilipolytic effects through G
i-dependent inhibition of adenylyl cyclase. Using GPR81-deficient mice, we demonstrate that the receptor is not involved in the regulation of lipolysis during intensive exercise. However, insulin-induced inhibition of lipolysis and insulin-induced decrease in adipocyte cAMP levels were strongly reduced in mice lacking GPR81, although insulin-dependent release of lactate by adipocytes was comparable between wild-type and GPR81-deficient mice. Thus, lactate and its receptor GPR81 unexpectedly function in an autocrine and paracrine loop to mediate insulin-induced antilipolytic effects. These data show that lactate can directly modulate metabolic processes in a hormone-like manner, and they reveal a new mechanism underlying the antilipolytic effects of insulin.
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► Lactate inhibits lipolysis through activation of GPR81 in adipose tissue ► Lactate is released from adipocytes upon insulin-dependent glucose uptake ► Lactate and GPR81 mediate insulin-induced antilipolytic effects
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