Effect of Controlled Crossing on the Triglyceride and Fatty Acid Composition of Virgin Olive Oils

Our study reports the triglyceride (triacylglycerol, TAG) composition of five new Tunisian virgin olive oil cultivars obtained through controlled crossings of the cultivar (cv.) Chemlali Sfax. These cultivars have been selected among a progeny of 500 olive descendants, based on an evaluation of the fatty‐acid (FA) composition of their oils. Among these samples, two were derived from the crossing with the cv. Sigoise as pollinator (SM634) or pollen acceptor (SM1110) and the others from the crossing with the cv. Meski as pollen acceptor (SM513, SM514, and SM517). The five descendants were characterized by a good fat value, a balanced FA composition, and a high content of triolein, varying between 26.9 (SM514) and 45.46% (SM1110). They had an improved FA composition as compared to that of the cv. Chemlali Sfax and their fruits were slightly bigger. The principal component analysis suggested that the TAG variables were more suitable than the total FAs for an optimum classification of the cultivar samples analyzed. The cultivars obtained through the crossing with the cv. Sigoise (as pollen acceptor or pollinator) had a more favorable composition of FAs and TAG than those obtained through the crossing with the cv. Meski, which indicated that genetic factors had the most important influence on the quality of the virgin olive oils.     

Volatile Composition Screening of Salix spp. Nectar Honey: Benzenecarboxylic Acids,Norisoprenoids, Terpenes,and Others

Salix spp. nectar honey volatiles of Croatian origin were analyzed by headspace solid‐phase microextraction (HS‐SPME) and ultrasonic solvent extraction (USE), followed by gas chromatography and mass spectrometry (GC, GC/MS). Isolated volatiles were found in the honey headspace and extracts with almost exclusive distribution of several abundant compounds (e.g., phenylacetic acid, pinocembrin, 8‐hydroxy‐4,7‐dimethylcoumarin, and 3‐hydroxy‐trans‐β‐damascone in the extracts, or safranal and lilac alcohols in the headspace). Comparison with Croatian Salix spp. honeydew honey revealed similarities regarding distribution of important shikimate pathway derivatives (e.g., high percentage of phenylacetic acid) and several norisoprenoids (α‐isophorone and 4‐oxoisophorone). On the other hand, distinct features of this honey were occurrence of compounds such as pinocembrin, 8‐hydroxy‐4,7‐dimethylcoumarin, phenylacetonitrile, norisoprenoids (major ones: 3‐hydroxy‐trans‐β‐damascenone and trans‐β‐damascone), more pronounced variability of linalool‐derived compounds, as well as the abundance of 3‐methylpropanoic acid, 3‐methylbutanoic acid, 2‐methylpentanoic acid, and 3‐methylpentan‐1‐ol.     

SILAC analysis of oxidative stress‐mediated proteins in human pneumocytes: New role for treacle

To better understand lung oxidant stress responses, we examined A549 lung cells exposed to H₂O₂ using “stable isotope labeling by amino acids.” We identified 466 cytosolic and 387 nuclear proteins; H₂O₂ exposure produced ≥twofold differences in 31, all were downregulations. None were previously reported as oxidant stress response proteins, although they share common functions. One of the responders, treacle, was linked to p53, an important oxidative stress response. The Treacher Collins–Franceschetti syndrome can result from treacle mutation and insufficiency was suggested to cause increased p53 leading to the syndrome. However, results here indicate p53 and treacle responses to H₂O₂ are independent: treacle remains suppressed after p53 recovery; the threshold for treacle reduction is well above that for p53 induction; and treacle suppression by short interfering RNA does not modify the p53 response. Evidence of treacle antioxidant activity include reduction being driven by proteasome degradation independently of mRNA, typical for oxidant‐absorbing proteins, and increased sensitivity to H₂O₂ consequent to short interfering RNA suppression. Data here show a link between oxidative stress and treacle reduction, demonstrate that treacle does not control p53, provide evidence of a treacle oxidant defense role, support the hypothesis that oxidant stress plays a role in the Treacher Collins–Franceschetti syndrome, and raise the possibility that treacle plays an anti‐oxidant role in lungs.     

Role of very-long-chain fatty acids in plant development,when chain length does matter

Very long chain fatty acids (VLCFAs) are essential components for eukaryotes. They are elongated by the elongase complex in the endoplasmic reticulum and are incorporated into four major lipid pools (triacylglycerols, waxes, phospholipids, complex sphingolipids). Functional analysis of several components of the elongase complex demonstrated the essential role of VLCFAs in plants, invertebrates and vertebrates. Although VLCFAs changes in the triacylglycerol pool has no consequence for plant development, modifications of the nature and levels of VLCFAs in waxes, phospholipids and complex sphingolipids have, collectively, profound effects on embryo, leaf, root and flower development. VLCFAs levels in epicuticular waxes are critical for the regulation of epidermal fusions during organogenesis. VLCFAs phospholipids and sphingolipids are involved in membrane structure and dynamics regulating cell size but also division and differentiation. This review summarizes the recent findings in plants but also in other organisms, highlighting the importance of very long acyl chain length during development.     

Testosterone affects hormone-sensitive lipase (HSL) activity and lipid metabolism in the left ventricle

Fatty acids, which are the major cardiac fuel, are derived from lipid droplets stored in cardiomyocytes, among other sources. The heart expresses hormone-sensitive lipase (HSL), which regulates triglycerides (TG) breakdown, and the enzyme is under hormonal control. Evidence obtained from adipose tissue suggests that testosterone regulates HSL activity. To test whether this is also true in the heart, we measured HSL activity in the left ventricle of sedentary male rats that had been treated with testosterone supplementation or orchidectomy with or without testosterone substitution. Left ventricle HSL activity against TG was significantly elevated in intact rats supplemented with testosterone. HSL activity against both TG and diacylglyceride was reduced by orchidectomy, whereas testosterone replacement fully reversed this effect. Moreover, testosterone increased left ventricle free fatty acid levels, caused an inhibitory effect on carbohydrate metabolism in the heart, and elevated left ventricular phosphocreatine and ATP levels as compared to control rats. These data indicate that testosterone is involved in cardiac HSL activity regulation which, in turn, may affect cardiac lipid and carbohydrate metabolism.     

Carbohydrate quantitative digestion and absorption in ruminants: from feed starch and fibre to nutrients available for tissues

Carbohydrates are the main source of energy in ruminants. Their site, extent and kinetics of digestion highly impact the amount and profile of nutrients delivered to peripheral tissues, and the responses of the animal, i.e. ingestion, efficiency of production, N and methane excretion, quality of products and welfare. Development of multi-objective feed evaluation systems thus requires a more integrated quantitative knowledge on carbohydrate digestion and yield of terminal products, as well as on their metabolism by splanchnic tissues. The objective of this paper is to review (i) quantitative knowledge on fibre, starch and sugar digestion, volatile fatty acids (VFA) and glucose production and splanchnic metabolism and (ii) modelling approaches which aim at representing and/or predicting nutrient fluxes in the digestive tract, portal and hepatic drainage. It shows that the representation of carbohydrate digestion and VFA yield is relatively homogeneous among models. Although published quantitative comparisons of these models are scarce, they stress that prediction of fibre digestion and VFA yield and composition is still not good enough for use in feed formulation, whereas prediction of microbial N yield and ruminal starch digestion seems to be more satisfactory. Uncertainties on VFA stoichiometric coefficients and absorption rates may partly explain the poor predictions of VFA. Hardly any mechanistic models have been developed on portal-drained viscera (PDV) metabolism whereas a few exist for liver metabolism. A qualitative comparison of these models is presented. Most are focused on dairy cows and their level of aggregation in the representation of nutrient fluxes and metabolism highly differs depending on their objectives. Quantitative comparison of these models is still lacking. However, recent advances have been achieved with the empirical prediction of VFA and glucose production and fluxes through PDV and liver based on the current INRA feed evaluation system. These advances are presented. They illustrate that empirical prediction of ruminal VFA and intestinal glucose production can be evaluated by comparison with measured net portal net fluxes. We also illustrate the potential synergy between empirical and mechanistic modelling. It is concluded that concomitant empirical and mechanistic approach may likely help to progress towards development of multi-objective feed evaluation systems based on nutrient fluxes.     

Effect of n-3 and n-6 polyunsaturated fatty acids on hare reproductive performances

The study was carried out on 42 breeder couples (42 males and 42 females) of European brown hare (Lepus europaeus), divided into three groups fed three different experimental diets (14 couples/treatment). Two diets were supplemented with n-3 and n-6 polyunsaturated fatty acids (PUFAs; 2% of linseed oil and soybean oil, respectively) and were compared with a control diet supplemented with a monounsaturated fatty acids (2% of olive oil). During the experimental period (from 15 April to 30 September), the following parameters were recorded: days from the beginning of trial to the first parturition, parturition interval, number of parturitions, number of leverets born (alive and dead), dead during suckling, the total number of leverets weaned and feed intake per cage (of males, females and leverets until weaning). Feed intake was not influenced by treatments. In hares fed n-3 and n-6 diets, the days from the beginning of the trial to the first parturition and the parturition interval were similar and were lower compared with control group (63.1 v. 70.6 days, and 37.8 v. 40.9 days, respectively; P < 0.05). Hares from n-6 group had a higher (P < 0.05) number of parturitions per cage during the experimental period than the n-3 and control group that showed a similar value (3.00 v. 2.36, respectively). The total number of leverets born per cage and parturition in n-6 and n-3 groups increased with respect to those fed control diet (P < 0.05). The leverets' mortality rate at birth was higher in n-6 than in n-3 and control group (3.50 v. 2.17, respectively; P < 0.05). In control group, leverets' mortality rate during suckling was lower with respect to n-3 (P < 0.05) and n-6 (P < 0.05), showing the highest value for the latter (P < 0.05). In spite of this higher mortality, the number of leverets weaned per cage and parturition was higher (P < 0.05) in n-6 compared with n-3 group, being the latter higher than the control group (3.12, 2.79 and 2.43, respectively). Our results show that the dietary PUFAs, particularly n-6 supplementation, have a positive influence on the reproductive performances of the European brown hare.     

Daunomycin interaction with DNA: Microcalorimetric studies of the thermodynamics and binding mechanism

Nucleic acids are an important target for many therapeutics. Small molecules that bind to nucleic acids are important in many aspects of medicines, particularly in cancer chemotherapy. In recent years, many studies have utilized polynucleic acids with various sequences to demonstrate the binding mechanism of daunomycin, a potent anticancer drug. This study describes that isothermal titration calorimetry is a useful tool for studying the fundamental binding mechanism systemically. The results suggest that the binding free energy is more favorable when the temperature is increased. The binding entropy contributes to this effect. Furthermore, the amine group on daunomycin contributes electrostatic interaction that induces the binding process. In addition, enthalpy-entropy compensation is also exhibited in the daunomycin-DNA binding mechanism. This study used an easy, convenient method of performing a systemic study in a recognition system. The results from this study provide additional information about microscopic mechanisms for molecular design and molecular recognition.     

ArfGAP1 inhibits mTORC1 lysosomal localization and activation

The mammalian target of rapamycin complex 1 (mTORC1) integrates nutrients, growth factors, stress, and energy status to regulate cell growth and metabolism. Amino acids promote mTORC1 lysosomal localization and subsequent activation. However, the subcellular location or interacting proteins of mTORC1 under amino acid‐deficient conditions is not completely understood. Here, we identify ADP‐ribosylation factor GTPase‐activating protein 1 (ArfGAP1) as a crucial regulator of mTORC1. ArfGAP1 interacts with mTORC1 in the absence of amino acids and inhibits mTORC1 lysosomal localization and activation. Mechanistically, the membrane curvature‐sensing amphipathic lipid packing sensor (ALPS) motifs that bind to vesicle membranes are crucial for ArfGAP1 to interact with and regulate mTORC1 activity. Importantly, ArfGAP1 represses cell growth through mTORC1 and is an independent prognostic factor for the overall survival of pancreatic cancer patients. Our study identifies ArfGAP1 as a critical regulator of mTORC1 that functions by preventing the lysosomal transport and activation of mTORC1, with potential for cancer therapeutics.