Circadian Control of Lipid Metabolism.

To ensure optimum health and performance, lipid metabolism needs to be temporally aligned to other body processes and to daily changes in the environment. Central and peripheral circadian clocks and environmental signals such as light provide internal and external time cues to the body. Importantly, each of the key organs involved in insect lipid metabolism contains a molecular clockwork which ticks with a varying degree of autonomy from the central clock in the brain. In this chapter, we review our current knowledge about peripheral clocks in the insect fat body, gut and oenocytes, and light- and circadian-driven diel patterns in lipid metabolites and lipid-related transcripts. In addition, we highlight selected neuroendocrine signaling pathways that are or may be involved in the temporal coordination and control of lipid metabolism.

The Role of Neutral Sphingomyelinase-2 (NSM2) in the Control of Neutral Lipid Storage in T Cells.

The accumulation of lipid droplets (LDs) and ceramides (Cer) is linked to non-alcoholic fatty liver disease (NAFLD), regularly co-existing with type 2 diabetes and decreased immune function. Chronic inflammation and increased disease severity in viral infections are the hallmarks of the obesity-related immunopathology. The upregulation of neutral sphingomyelinase-2 (NSM2) has shown to be associated with the pathology of obesity in tissues. Nevertheless, the role of sphingolipids and specifically of NSM2 in the regulation of immune cell response to a fatty acid (FA) rich environment is poorly studied. Here, we identified the presence of the LD marker protein perilipin 3 (PLIN3) in the intracellular nano-environment of NSM2 using the ascorbate peroxidase APEX2-catalyzed proximity-dependent biotin labeling method. In line with this, super-resolution structured illumination microscopy (SIM) shows NSM2 and PLIN3 co-localization in LD organelles in the presence of increased extracellular concentrations of oleic acid (OA). Furthermore, the association of enzymatically active NSM2 with isolated LDs correlates with increased Cer levels in these lipid storage organelles. NSM2 enzymatic activity is not required for NSM2 association with LDs, but negatively affects the LD numbers and cellular accumulation of long-chain unsaturated triacylglycerol (TAG) species. Concurrently, NSM2 expression promotes mitochondrial respiration and fatty acid oxidation (FAO) in response to increased OA levels, thereby shifting cells to a high energetic state. Importantly, endogenous NSM2 activity is crucial for primary human CD4+ T cell survival and proliferation in a FA rich environment. To conclude, our study shows a novel NSM2 intracellular localization to LDs and the role of enzymatically active NSM2 in metabolic response to enhanced FA concentrations in T cells.

The circadian clock is required for rhythmic lipid transport in Drosophila in interaction with diet and photic condition.

Modern lifestyle is often at odds with endogenously driven rhythmicity, which can lead to circadian disruption and metabolic syndrome. One signature for circadian disruption is a reduced or altered metabolite cycling in the circulating tissue reflecting the current metabolic status. Drosophila is a well-established model in chronobiology, but day-time dependent variations of transport metabolites in the fly circulation are poorly characterized. Here, we sampled fly hemolymph throughout the day and analyzed diacylglycerols (DGs), phosphoethanolamines (PEs) and phosphocholines (PCs) using LC-MS. In wild-type flies kept on sugar-only medium under a light-dark cycle, all transport lipid species showed a synchronized bimodal oscillation pattern with maxima at the beginning and end of the light phase which were impaired in period01 clock mutants. In wild-type flies under constant dark conditions, the oscillation became monophasic with a maximum in the middle of the subjective day. In strong support of clock-driven oscillations, levels of the targeted lipids peaked once in the middle of the light phase under time-restricted feeding independent of the time of food intake. When wild-type flies were reared on full standard medium, the rhythmic alterations of hemolymph lipid levels were greatly attenuated. Our data suggest that the circadian clock aligns daily oscillations of DGs, PEs, and PCs in the hemolymph to the anabolic siesta phase, with a strong influence of light on phase and modality.

The major trimeric antenna complexes serve as a site for qH-energy dissipation in plants.

Plants and algae are faced with a conundrum: harvesting sufficient light to drive their metabolic needs while dissipating light in excess to prevent photodamage, a process known as nonphotochemical quenching. A slowly relaxing form of energy dissipation, termed qH, is critical for plants' survival under abiotic stress; however, qH location in the photosynthetic membrane is unresolved. Here, we tested whether we could isolate subcomplexes from plants in which qH was induced that would remain in an energy-dissipative state. Interestingly, we found that chlorophyll (Chl) fluorescence lifetimes were decreased by qH in isolated major trimeric antenna complexes, indicating that they serve as a site for qH-energy dissipation and providing a natively quenched complex with physiological relevance to natural conditions. Next, we monitored the changes in thylakoid pigment, protein, and lipid contents of antenna with active or inactive qH but did not detect any evident differences. Finally, we investigated whether specific subunits of the major antenna complexes were required for qH but found that qH was insensitive to trimer composition. Because we previously observed that qH can occur in the absence of specific xanthophylls, and no evident changes in pigments, proteins, or lipids were detected, we tentatively propose that the energy-dissipative state reported here may stem from Chl-Chl excitonic interaction.

Sphingolipid Long-Chain Base Phosphate Degradation Can Be a Rate-Limiting Step in Long-Chain Base Homeostasis.

Sphingolipid long-chain bases (LCBs) are building blocks for membrane-localized sphingolipids, and are involved in signal transduction pathways in plants. Elevated LCB levels are associated with the induction of programmed cell death and pathogen-derived toxin-induced cell death. Therefore, levels of free LCBs can determine survival of plant cells. To elucidate the contribution of metabolic pathways regulating high LCB levels, we applied the deuterium-labeled LCB D-erythro-sphinganine-d7 (D7-d18:0), the first LCB in sphingolipid biosynthesis, to Arabidopsis leaves and quantified labeled LCBs, LCB phosphates (LCB-Ps), and 14 abundant ceramide (Cer) species over time. We show that LCB D7-d18:0 is rapidly converted into the LCBs d18:0P, t18:0, and t18:0P. Deuterium-labeled ceramides were less abundant, but increased over time, with the highest levels detected for Cer(d18:0/16:0), Cer(d18:0/24:0), Cer(t18:0/16:0), and Cer(t18:0/22:0). A more than 50-fold increase of LCB-P levels after leaf incubation in LCB D7-d18:0 indicated that degradation of LCBs via LCB-Ps is important, and we hypothesized that LCB-P degradation could be a rate-limiting step to reduce high levels of LCBs. To functionally test this hypothesis, we constructed a transgenic line with dihydrosphingosine-1-phosphate lyase 1 (DPL1) under control of an inducible promotor. Higher expression of DPL1 significantly reduced elevated LCB-P and LCB levels induced by Fumonisin B1, and rendered plants more resistant against this fungal toxin. Taken together, we provide quantitative data on the contribution of major enzymatic pathways to reduce high LCB levels, which can trigger cell death. Specifically, we provide functional evidence that DPL1 can be a rate-limiting step in regulating high LCB levels.

The evolutionarily conserved kinase SnRK1 orchestrates resource mobilization during Arabidopsis seedling establishment.

The onset of plant life is characterized by a major phase transition. During early heterotrophic seedling establishment, seed storage reserves fuel metabolic demands, allowing the plant to switch to autotrophic metabolism. Although metabolic pathways leading to storage compound mobilization are well-described, the regulatory circuits remain largely unresolved. Using an inducible knockdown approach of the evolutionarily conserved energy master regulator Snf1-RELATED-PROTEIN-KINASE1 (SnRK1), phenotypic studies reveal its crucial function in Arabidopsis thaliana seedling establishment. Importantly, glucose feeding largely restores growth defects of the kinase mutant, supporting its major impact in resource mobilization. Detailed metabolite studies reveal sucrose as a primary resource early in seedling establishment, in a SnRK1-independent manner. Later, SnRK1 orchestrates catabolism of triacylglycerols and amino acids. Concurrent transcriptomic studies highlight SnRK1 functions in controlling metabolic hubs fuelling gluconeogenesis, as exemplified by cytosolic PYRUVATE ORTHOPHOSPHATE DIKINASE (cyPPDK). Here, SnRK1 establishes its function via phosphorylation of the transcription factor BASIC LEUCINE ZIPPER63 (bZIP63), which directly targets and activates the cyPPDK promoter. Taken together, our results disclose developmental and catabolic functions of SnRK1 in seed storage mobilization and describe a prototypic gene regulatory mechanism. As seedling establishment is important for plant vigor and crop yield, our findings are of agronomical importance.

Endocrine signals fine-tune daily activity patterns in Drosophila.

Animals need to balance competitive behaviors to maintain internal homeostasis. The underlying mechanisms are complex but typically involve neuroendocrine signaling. Using Drosophila, we systematically manipulated signaling between energy-mobilizing endocrine cells producing adipokinetic hormone (AKH), octopaminergic neurons, and the energy-storing fat body to assess whether this neuroendocrine axis involved in starvation-induced hyperactivity also balances activity levels under ad libitum access to food. Our results suggest that AKH signals via two divergent pathways that are mutually competitive in terms of activity and rest. AKH increases activity via the octopaminergic system during the day, while it prevents high activity levels during the night by signaling to the fat body. This regulation involves feedback signaling from octopaminergic neurons to AKH-producing cells (APCs). APCs are known to integrate a multitude of metabolic and endocrine signals. Our results add a new facet to the versatile regulatory functions of APCs by showing that their output contributes to shape the daily activity pattern under ad libitum access to food.

Chemical Priming by Isothiocyanates Protects Against Intoxication by Products of the Mustard Oil Bomb.

In Brassicaceae, tissue damage triggers the mustard oil bomb i.e., activates the degradation of glucosinolates by myrosinases leading to a rapid accumulation of isothiocyanates at the site of damage. Isothiocyanates are reactive electrophilic species (RES) known to covalently bind to thiols in proteins and glutathione, a process that is not only toxic to herbivores and microbes but can also cause cell death of healthy plant tissues. Previously, it has been shown that subtoxic isothiocyanate concentrations can induce transcriptional reprogramming in intact plant cells. Glutathione depletion by RES leading to breakdown of the redox potential has been proposed as a central and common RES signal transduction mechanism. Using transcriptome analyses, we show that after exposure of Arabidopsis seedlings (grown in liquid culture) to subtoxic concentrations of sulforaphane hundreds of genes were regulated without depletion of the cellular glutathione pool. Heat shock genes were among the most highly up-regulated genes and this response was found to be dependent on the canonical heat shock factors A1 (HSFA1). HSFA1-deficient plants were more sensitive to isothiocyanates than wild type plants. Moreover, pretreatment of Arabidopsis seedlings with subtoxic concentrations of isothiocyanates increased resistance against exposure to toxic levels of isothiocyanates and, hence, may reduce the autotoxicity of the mustard oil bomb by inducing cell protection mechanisms.

Loss of function in the Drosophila clock gene period results in altered intermediary lipid metabolism and increased susceptibility to starvation.

The fruit fly Drosophila is a prime model in circadian research, but still little is known about its circadian regulation of metabolism. Daily rhythmicity in levels of several metabolites has been found, but knowledge about hydrophobic metabolites is limited. We here compared metabolite levels including lipids between period01 (per01) clock mutants and Canton-S wildtype (WTCS) flies in an isogenic and non-isogenic background using LC-MS. In the non-isogenic background, metabolites with differing levels comprised essential amino acids, kynurenines, pterinates, glycero(phospho)lipids, and fatty acid esters. Notably, detectable diacylglycerols (DAG) and acylcarnitines (AC), involved in lipid metabolism, showed lower levels in per01 mutants. Most of these differences disappeared in the isogenic background, yet the level differences for AC as well as DAG were consistent for fly bodies. AC levels were dependent on the time of day in WTCS in phase with food consumption under LD conditions, while DAGs showed weak daily oscillations. Two short-chain ACs continued to cycle even in constant darkness. per01 mutants in LD showed no or very weak diel AC oscillations out of phase with feeding activity. The low levels of DAGs and ACs in per01 did not correlate with lower total food consumption, body mass or weight. Clock mutant flies showed higher sensitivity to starvation independent of their background-dependent activity level. Our results suggest that neither feeding, energy storage nor mobilisation is significantly affected in per01 mutants, but point towards impaired mitochondrial activity, supported by upregulation of the mitochondrial stress marker 4EBP in the clock mutants.

Whey protein lowers systolic blood pressure and Ca-caseinate reduces serum TAG after a high-fat meal in mildly hypertensive adults.

Epidemiological studies show an inverse association between dairy consumption and blood pressure (BP) but there are few data on the postprandial effects of milk proteins. This study examined their effects, compared to maltodextrin, on postprandial BP and other CVD risk markers in volunteers with mild and pre-hypertension over an 8 h period. In this double-blinded, randomised, cross-over, controlled study 27 adults ingested a high-fat, isoenergetic breakfast and lunch with 28 g whey protein, 28 g Ca-caseinate or 27 g maltodextrin. Whey protein reduced systolic BP compared with Ca-caseinate (-15.2 ± 13.6 mmHg) and maltodextrin (-23.4 ± 10.5 mmHg) up to 5 h post-ingestion. There was an improvement in arterial stiffness after whey protein compared with maltodextrin (incremental Area Under the Curve- iAUC0-8h: +14.4 ± 6.2%). Despite similar glucose levels after both whey protein and Ca-caseinate, whey protein induced a higher insulin response than Ca-caseinate (iAUC0-8h: +219.5 ± 54.6 pmol/L). Ca-caseinate induced less suppression of non-esterified fatty acids than whey protein (iAUC0-5h: -58.9 ± 135.5 µmol/L) and maltodextrin (iAUC0-5h: -106.9 ± 89.4 µmol/L) and induced a smaller postprandial triacylglycerol response than whey protein (iAUC0-8h: -1.68 ± 0.6 mmol/L). Milk proteins co-ingestion with high-fat meals may have the potential to maintain or improve CVD risk factors.

Short-Communication: A Comparison of the In Vitro Angiotensin-1-Converting Enzyme Inhibitory Capacity of Dairy and Plant Protein Supplements.

The consumption of supplements based on dairy or plant proteins may be associated with bioactive potential, including angiotensin-1-converting enzyme inhibitory (ACE-1i) activity, which is linked with blood pressure reduction in vivo. To gain insight into this proposed mechanism, the ACE-1i potential of protein-based supplements, including a selection of dairy (n = 10) and plant (n = 5) proteins were in vitro digested. The total digest was filtered and permeate and retentate were obtained. ACE-1i activity was measured as the ability of proteins (pre-digestion, 'gastric', permeate, and retentate) to decrease the hydrolysis of furanacroloyl-Phe-Glu-Glu (FAPGG) substrate for the ACE-1 enzyme. Permeate and retentate of dairy proteins exerted a significantly higher ACE-1i activity (mean of 10 proteins: 27.05 ± 0.2% and 20.7 ± 0.2%, respectively) compared with pre-digestion dairy proteins (16.7 ± 0.3%). Plant protein exhibited high ACE-1i in 'gastric' and retentate fractions (mean of five proteins: 54.9 ± 0.6% and 35.7 ± 0.6%, respectively). The comparison of the in vitro ACE-1i activity of dairy and plant proteins could provide valuable knowledge regarding their specific bioactivities, which could inform their use in the formulation of specific functional supplements that would require testing for blood pressure control in human randomly-controlled studies.

Membrane Microdomain Disassembly Inhibits MRSA Antibiotic Resistance.

A number of bacterial cell processes are confined functional membrane microdomains (FMMs), structurally and functionally similar to lipid rafts of eukaryotic cells. How bacteria organize these intricate platforms and what their biological significance is remain important questions. Using the pathogen methicillin-resistant Staphylococcus aureus (MRSA), we show here that membrane-carotenoid interaction with the scaffold protein flotillin leads to FMM formation, which can be visualized using super-resolution array tomography. These membrane platforms accumulate multimeric protein complexes, for which flotillin facilitates efficient oligomerization. One of these proteins is PBP2a, responsible for penicillin resistance in MRSA. Flotillin mutants are defective in PBP2a oligomerization. Perturbation of FMM assembly using available drugs interferes with PBP2a oligomerization and disables MRSA penicillin resistance in vitro and in vivo, resulting in MRSA infections that are susceptible to penicillin treatment. Our study demonstrates that bacteria possess sophisticated cell organization programs and defines alternative therapies to fight multidrug-resistant pathogens using conventional antibiotics.

Phospholipid:Diacylglycerol Acyltransferase-Mediated Triacylglyerol Synthesis Augments Basal Thermotolerance.

High temperatures rapidly induce a genetically programmed heat-shock response (HSR) that is essential to establish short-term acquired thermotolerance. In addition, an immediate HSR-independent metabolic response is triggered, resulting in an accumulation of unsaturated triacylglycerols (TAGs) in the cytosol. The metabolic processes involved in heat-induced TAG formation in plants and their physiological significance remain to be clarified. Lipidomic analyses of Arabidopsis (Arabidopsis thaliana) seedlings indicated that during heat stress, polyunsaturated fatty acids from thylakoid galactolipids are incorporated into cytosolic TAGs. In addition, rapid conversion of plastidic monogalactosyl diacylglycerols (MGDGs) into oligogalactolipids, acylated MGDGs, and diacylglycerols (DAGs), the direct precursor of TAGs, was observed. For TAG synthesis, DAG requires a fatty acid from the acyl-CoA pool or phosphatidylcholine. Since seedlings deficient in PHOSPHOLIPID:DIACYLGLYCEROL ACYLTRANSFERASE1 (PDAT1) were unable to accumulate TAGs after heat stress, phosphatidylcholine appears to be the major fatty acid donor. Results suggest that rapid plastid lipid metabolism drives TAG accumulation during heat stress. PDAT1-mediated TAG accumulation was found to increase heat resistance, since nonacclimated pdat1 mutant seedlings were more sensitive to severe heat stress, as indicated by a more dramatic decline of the maximum efficiency of PSII and lower seedling survival compared to wild-type seedlings. In contrast, nonacclimated trigalactosyldiacylglycerol1 (tgd1) mutants overaccumulating TAGs and oligogalactolipids were more resistant to heat stress. Hence, thylakoid lipid metabolism and TAG formation increases thermotolerance in addition to the genetically encoded HSR.

Enzymatic and Non-Enzymatic Mechanisms Contribute to Lipid Oxidation During Seed Aging.

Storage of seeds is accompanied by loss of germination and oxidation of storage and membrane lipids. A lipidomic analysis revealed that during natural and artificial aging of Arabidopsis seeds, levels of several diacylglycerols and free fatty acids, such as linoleic acid and linolenic acid as well as free oxidized fatty acids and oxygenated triacylglycerols, increased. Lipids can be oxidized by enzymatic or non-enzymatic processes. In the enzymatic pathway, lipoxygenases (LOXs) catalyze the first oxygenation step of polyunsaturated fatty acids. Analysis of lipid levels in mutants with defects in the two 9-LOX genes revealed that the strong increase in free 9-hydroxy- and 9-keto-fatty acids is dependent on LOX1 but not LOX5. Fatty acid oxidation correlated with an aging-induced decrease of germination, raising the question of whether these oxylipins negatively regulate germination. However, seeds of the lox1 mutant were only slightly more tolerant to aging, indicating that 9-LOX products contribute to but are not the major cause of loss of germination during aging. In contrast to free oxidized fatty acids, accumulation of oxygenated triacylglycerols upon accelerated aging was mainly based on non-enzymatic oxidation of seed storage lipids.

Inhibitory potential of strepthonium A against Shiga toxin production in enterohemorrhagic Escherichia coli (EHEC) strain EDL933.

The production of shiga toxin (Stx) is a critical step in the establishment and progress of enterohemorrhagic Escherichia coli (EHEC) infections. The possible release of Stx from dead and dying bacteria, and the risk of resistance development have restricted the usage of antibiotics against EHEC. The chlorinated quaternary ammonium compound, strepthonium A, was isolated from the culture of Streptomyces sp. SBT345 that was cultivated from the Mediterranean sponge Agelas oroides. The structure was elucidated and confirmed by spectroscopic analyses including 1D and 2D NMR, ESI-HRMS, as well as ESI-HRMS2. Strepthonium A follows Lipinski's rule of five with respect to its molecular weight, CLogP values and the number of hydrogen acceptors and donors. Verotoxin ELISA assay demonstrated that Strepthonium A reduced the Stx production in EHEC strain EDL933 at 80 µM concentration without growth inhibition. This study demonstrates the potential of strepthonium A in restraining the production of Stx in EHEC infections.

Whey protein lowers blood pressure and improves endothelial function and lipid biomarkers in adults with prehypertension and mild hypertension: results from the chronic Whey2Go randomized controlled trial.

BACKGROUND: Cardiovascular diseases (CVDs) are the greatest cause of death globally, and their reduction is a key public-health target. High blood pressure (BP) affects 1 in 3 people in the United Kingdom, and previous studies have shown that milk consumption is associated with lower BP. OBJECTIVE: We investigated whether intact milk proteins lower 24-h ambulatory blood pressure (AMBP) and other risk markers of CVD. DESIGN: The trial was a double-blinded, randomized, 3-way-crossover, controlled intervention study. Forty-two participants were randomly assigned to consume 2 × 28 g whey protein/d, 2 × 28 g Ca caseinate/d, or 2 × 27 g maltodextrin (control)/d for 8 wk separated by a 4-wk washout. The effects of these interventions were examined with the use of a linear mixed-model ANOVA. RESULTS: Thirty-eight participants completed the study. Significant reductions in 24-h BP [for systolic blood pressure (SBP): -3.9 mm Hg; for diastolic blood pressure (DBP): -2.5 mm Hg; P = 0.050 for both)] were observed after whey-protein consumption compared with control intake. After whey-protein supplementation compared with control intake, peripheral and central systolic pressures [-5.7 mm Hg (P = 0.007) and -5.4 mm Hg (P = 0.012), respectively] and mean pressures [-3.7 mm Hg (P = 0.025) and -4.0 mm Hg (P = 0.019), respectively] were also lowered. Flow-mediated dilation (FMD) increased significantly after both whey-protein and calcium-caseinate intakes compared with control intake [1.31% (P < 0.001) and 0.83% (P = 0.003), respectively]. Although both whey protein and calcium caseinate significantly lowered total cholesterol [-0.26 mmol/L (P = 0.013) and -0.20 mmol/L (P = 0.042), respectively], only whey protein decreased triacylglycerol (-0.23 mmol/L; P = 0.025) compared with the effect of the control. Soluble intercellular adhesion molecule 1 and soluble vascular cell adhesion molecule 1 were reduced after whey protein consumption (P = 0.011) and after calcium-caseinate consumption (P = 0.039), respectively, compared with after control intake. CONCLUSIONS: The consumption of unhydrolyzed milk proteins (56 g/d) for 8 wk improved vascular reactivity, biomarkers of endothelial function, and lipid risk factors. Whey-protein supplementation also lowered 24-h ambulatory SBP and DBP. These results may have important implications for public health. This trial was registered at clinicaltrials.gov as NCT02090842.

An essential developmental function for murine phosphoglycolate phosphatase in safeguarding cell proliferation.

Mammalian phosphoglycolate phosphatase (PGP) is thought to target phosphoglycolate, a 2-deoxyribose fragment derived from the repair of oxidative DNA lesions. However, the physiological role of this activity and the biological function of the DNA damage product phosphoglycolate is unknown. We now show that knockin replacement of murine Pgp with its phosphatase-inactive PgpD34N mutant is embryonically lethal due to intrauterine growth arrest and developmental delay in midgestation. PGP inactivation attenuated triosephosphate isomerase activity, increased triglyceride levels at the expense of the cellular phosphatidylcholine content, and inhibited cell proliferation. These effects were prevented under hypoxic conditions or by blocking phosphoglycolate release from damaged DNA. Thus, PGP is essential to sustain cell proliferation in the presence of oxygen. Collectively, our findings reveal a previously unknown mechanism coupling a DNA damage repair product to the control of intermediary metabolism and cell proliferation.

The CE-Way of Thinking: "All Is Relative!".

Over the last two decades the development of capillary electrophoresis instruments lead to systems with programmable sampler, separation column, separation buffer, and detection devices comparable visually in many aspects to the setup of classical chromatography.Two processes make capillary electrophoresis essentially different from chromatography and are the basis of the CE-way of thinking, namely, the injection type and the liquid flow within the capillary. (1) When the injection is made hydrodynamically (such as in most of the found applications in the literature), the injected volumes are directly dependent on the type and size of the separation capillary. (2) The buffer velocity is not pressure driven as in liquid chromatography but electrokinetically governed by the quality of the capillary surface (separation buffer dependant surface charge) inducing an electroosmotic flow (EOF). The EOF undergoes small variations and is not necessarily identical from one separation or day to the other. The direct consequence is an apparent nonreproducible migration time of the analytes, even though the own velocity of the ions is the same.The effective mobility (field strength normalized velocity) of the ions is a possible parameterization from acquired timescale to effective mobility-scale electropherograms leading to a reproducible visualization and better quantification with a direct relation to structural characters of the analytes (i.e., charge and size-see chapter on semiempirical modelization).

A Semiempirical Approach for a Rapid Comprehensive Evaluation of the Electrophoretic Behaviors of Small Molecules in Free Zone Electrophoresis.

A phenomenological model is proposed for the evaluation of relative electrophoretic migration of charged substances present in mixtures and for the rapid pH optimization prior CZE method development. The simple and robust model is based on the Offord model that takes account of the chemical structure. The effective charge and the molecular mass of the molecule are needed; the charge can easily be calculated from pK a obtained from known sources or simulated with existing pK-calculation programs. A first example was chosen with the separation of hydroxy-s-triazines to illustrate the applicability of this simple approach for determination of the first buffer-pH conditions prior experimental method optimization when separation of different ions is needed. In a second example, the confirmation of aminoalcohols in the CZE method development of unsaturated hexahydro-triazines and oxasolidines.

Can milk proteins be a useful tool in the management of cardiometabolic health? An updated review of human intervention trials.

The prevalence of cardiometabolic diseases is a significant public health burden worldwide. Emerging evidence supports the inverse association between greater dairy consumption and reduced risk of cardiometabolic diseases. Dairy proteins may have an important role in the favourable impact of dairy on human health such as blood pressure (BP), blood lipid and glucose control. The purpose of this review is to update and critically evaluate the evidence on the impacts of casein and whey protein in relation to metabolic function. Evidence from short-term clinical studies assessing postprandial responses to milk protein ingestion suggests benefits on vascular function independent of BP, as well as improvement in glycaemic homeostasis. Long-term interventions have been less conclusive, with some showing benefits and others indicating a lack of improvement in vascular function. During chronic consumption BP appears to be lowered and both dyslipidaemia and hyperglacaemia seem to be controlled. Limited number of trials investigated the effects of dairy proteins on oxidative stress and inflammation. Although the underlying mechanisms of milk proteins on cardiometabolic homeostasis remains to be elucidated, the most likely mechanism is to improve insulin resistance. The incorporation of meals enriched with dairy protein in the habitual diet may result in the beneficial effects on cardiometabolic health. Nevertheless, future well-designed, controlled studies are needed to investigate the relative effects of both casein and whey protein on BP, vascular function, glucose homeostasis and inflammation.