Omega-3 fatty acid exposure with a low-fat diet in patients with past hypertriglyceridemia-induced acute pancreatitis; an exploratory, randomized, open-label crossover study.

BACKGROUND: Omega-3 fatty acids (OM3-FAs) are recommended with a low-fat diet for severe hypertriglyceridemia (SHTG), to reduce triglycerides and acute pancreatitis (AP) risk. A low-fat diet may reduce pancreatic lipase secretion, which is required to absorb OM3-ethyl esters (OM3-EEs), but not OM3-carboxylic acids (OM3-CAs). METHODS: In this exploratory, randomized, open-label, crossover study, 15 patients with SHTG and previous AP were instructed to take OM3-CA (2 g or 4 g) and OM3-EE 4 g once daily for 4 weeks, while adhering to a low-fat diet. On day 28 of each treatment phase, a single dose was administered in the clinic with a liquid low-fat meal, to assess 24-h plasma exposure. Geometric least-squares mean ratios were used for between-treatment comparisons of baseline (day 0)-adjusted area under the plasma concentration versus time curves (AUC0-24) and maximum plasma concentrations (Cmax) for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). RESULTS: Before initiating OM3-FA treatment, mean baseline fasting plasma EPA + DHA concentrations (nmol/mL) were 723 for OM3-CA 2 g, 465 for OM3-CA 4 g and 522 for OM3-EE 4 g. At week 4, mean pre-dose fasting plasma EPA + DHA concentrations increased by similar amounts (+ 735 - + 768 nmol/mL) for each treatment. During the 24-h exposure assessment (day 28), mean plasma EPA + DHA increased from pre-dose to the maximum achieved concentration by + 32.7%, + 45.8% and + 3.1% with single doses of OM3-CA 2 g, OM3-CA 4 g and OM3-EE 4 g, respectively. Baseline-adjusted AUC0-24 was 60% higher for OM3-CA 4 g than for OM3-EE 4 g and baseline-adjusted Cmax was 94% higher (both non-significant). CONCLUSIONS: Greater 24-h exposure of OM3-CA versus OM3-EE was observed for some parameters when administered with a low-fat meal at the clinic on day 28. However, increases in pre-dose fasting plasma EPA + DHA over the preceding 4-week dosing period were similar between treatments, leading overall to non-significant differences in baseline (day 0)-adjusted AUC0-24 and Cmax EPA + DHA values. It is not clear why the greater 24-h exposure of OM3-CA versus OM3-EE observed with a low-fat meal did not translate into significantly higher pre-dose fasting levels of DHA + EPA with longer-term use. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02189252, Registered 23 June 2014.

Effects of dapagliflozin and n-3 carboxylic acids on non-alcoholic fatty liver disease in people with type 2 diabetes: a double-blind randomised placebo-controlled study.

AIMS/HYPOTHESIS: The EFFECT-II study aimed to investigate the effects of dapagliflozin and omega-3 (n-3) carboxylic acids (OM-3CA), individually or combined, on liver fat content in individuals with type 2 diabetes and non-alcoholic fatty liver disease (NAFLD). METHODS: This randomised placebo-controlled double-blind parallel-group study was performed at five clinical research centres at university hospitals in Sweden. 84 participants with type 2 diabetes and NAFLD were randomly assigned 1:1:1:1 to four treatments by a centralised randomisation system, and all participants as well as investigators and staff involved in the study conduct and analyses were blinded to treatments. Each group received oral doses of one of the following: 10 mg dapagliflozin (n = 21), 4 g OM-3CA (n = 20), a combination of both (n = 22) or placebo (n = 21). The primary endpoint was liver fat content assessed by MRI (proton density fat fraction [PDFF]) and, in addition, total liver volume and markers of glucose and lipid metabolism as well as of hepatocyte injury and oxidative stress were assessed at baseline and after 12 weeks of treatment (completion of the trial). RESULTS: Participants had a mean age of 65.5 years (SD 5.9), BMI 31.2 kg/m2 (3.5) and liver PDFF 18% (9.3). All active treatments significantly reduced liver PDFF from baseline, relative changes: OM-3CA, -15%; dapagliflozin, -13%; OM-3CA + dapagliflozin, -21%. Only the combination treatment reduced liver PDFF (p = 0.046) and total liver fat volume (relative change, -24%, p = 0.037) in comparison with placebo. There was an interaction between the PNPLA3 I148M polymorphism and change in liver PDFF in the active treatment groups (p = 0.03). Dapagliflozin monotherapy, but not the combination with OM-3CA, reduced the levels of hepatocyte injury biomarkers, including alanine aminotransferase, aspartate aminotransferase, γ-glutamyl transferase (γ-GT), cytokeratin (CK) 18-M30 and CK 18-M65 and plasma fibroblast growth factor 21 (FGF21). Changes in γ-GT correlated with changes in liver PDFF (ρ = 0.53, p = 0.02). Dapagliflozin alone and in combination with OM-3CA improved glucose control and reduced body weight and abdominal fat volumes. Fatty acid oxidative stress biomarkers were not affected by treatments. There were no new or unexpected adverse events compared with previous studies with these treatments. CONCLUSIONS/INTERPRETATION: Combined treatment with dapagliflozin and OM-3CA significantly reduced liver fat content. Dapagliflozin monotherapy reduced all measured hepatocyte injury biomarkers and FGF21, suggesting a disease-modifying effect in NAFLD. TRIAL REGISTRATION: ClinicalTrials.gov NCT02279407 FUNDING: The study was funded by AstraZeneca.

Importance of pancreatic exocrine dysfunction in patients with type 2 diabetes: A randomized crossover study.

BACKGROUND: Levels of faecal elastase-1 (FE-1), a marker of exocrine pancreatic function, are lower in patients with type 2 diabetes than without diabetes. We aimed to investigate the association between FE-1 and nutritional status, gastrointestinal symptoms, and lipid absorption. METHODS: This randomized, open-label, crossover study included 315 patients with type 2 diabetes aged 18-70 years treated with oral antidiabetics, with HbA1c 6.5-9.0% and BMI 18-40 kg/m2. Assessments included levels of FE-1 and blood biomarkers of nutrition, and Bristol Stool Scale and Gastrointestinal Symptom Rating Scale (GSRS) scores. Plasma exposure of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) after oral administration of free omega-3 carboxylic acids or ethyl esters with breakfast was investigated in patients with low, intermediate, and normal FE-1 levels. RESULTS: The prevalence of low and intermediate FE-1 levels was 5.2% and 4.9%, respectively. Bristol Stool Scale scores and mean values of GSRS Diarrhoea and Indigestion domain symptoms were similar across groups, but patients with low FE-1 were heavier and reported lower stool frequency. FE-1 levels correlated positively with plasma levels of amylase, lipase, 25-hydroxy vitamin D, and albumin. Mean EPA + DHA exposure was similarly higher after intake of free vs. esterified omega-3 fatty acids in all FE-1 groups. CONCLUSIONS: The prevalence of low FE-1 (<100 µg/g) as a measure of pancreatic exocrine insufficiency was infrequent in type 2 diabetes. Except for low plasma concentrations of EPA and 25-hydroxy vitamin D, type 2 diabetes patients with low FE-1 had no other signs of malabsorption or gastrointestinal disorders. Plasma levels of EPA and DHA after the intake of esterified versus free EPA and DHA did not correlate with FE-1 levels. TRIAL REGISTRATION: ClinicalTrials.gov NCT02370537.

Omega-3 carboxylic acids in patients with severe hypertriglyceridemia: EVOLVE II, a randomized, placebo-controlled trial.

BACKGROUND: Adult patients with severe hypertriglyceridemia (SHTG) are at increased risk of developing acute pancreatitis and cardiovascular disease. Omega-3 carboxylic acids (OM3-CA) are approved for treatment as an adjunct to diet to reduce triglyceride (TG) concentrations in patients with SHTG. OBJECTIVE: The aim of the study was to assess efficacy and safety of the intermediate dose of OM3-CA (2 g daily), compared with olive oil 2 g daily, in reducing serum TG and lipid concentrations in patients with SHTG. METHODS: A randomized, double-blind, olive oil-controlled, parallel-group trial involving 162 adults with qualifying serum TG concentrations of at least 500 mg/dL (5.65 mmol/L) and <2500 mg/dL (28.25 mmol/L; <2000 mg/dL [22.60 mmol/L] in Canada). The treatment period after randomization was 12 weeks. Blood samples for measurement of fasting serum lipid concentrations were taken at baseline, 6, 10, and 12 weeks. RESULTS: Treatment with OM3-CA 2 g daily led to a significant reduction in TG concentrations (median of differences, -14.2% [95% confidence interval: -26.2%, -2.8%; P = .017]) and non-high-density lipoprotein cholesterol concentrations (median of differences, -9.0% [95% confidence interval: -14.8%, -2.8%; adjusted P = .018]) from baseline to the Week 12 endpoint, when compared with olive oil 2 g daily. These treatment effects were more pronounced in patients with qualifying TG concentrations >885 mg/dL (10 mmol/L). CONCLUSION: An intermediate dose of OM3-CA (2 g daily) significantly lowers TG and non-high-density lipoprotein cholesterol concentrations in patients with SHTG and may benefit individuals at risk of acute pancreatitis and cardiovascular disease.

Heterogeneous kinetics of AKT signaling in individual cells are accounted for by variable protein concentration.

In most solid cancers, cells harboring oncogenic mutations represent only a sub-fraction of the entire population. Within this sub-fraction the expression level of mutated proteins can vary significantly due to cellular variability limiting the efficiency of targeted therapy. To address the causes of the heterogeneity, we performed a systematic analysis of one of the most frequently mutated pathways in cancer cells, the phosphatidylinositol 3 kinase (PI3K) signaling pathway. Among others PI3K signaling is activated by the hepatocyte growth factor (HGF) that regulates proliferation of hepatocytes during liver regeneration but also fosters tumor cell proliferation. HGF-mediated responses of PI3K signaling were monitored both at the single cell and cell population level in primary mouse hepatocytes and in the hepatoma cell line Hepa1_6. Interestingly, we observed that the HGF-mediated AKT responses at the level of individual cells is rather heterogeneous. However, the overall average behavior of the single cells strongly resembled the dynamics of AKT activation determined at the cell population level. To gain insights into the molecular cause for the observed heterogeneous behavior of individual cells, we employed dynamic mathematical modeling in a stochastic framework. Our analysis demonstrated that intrinsic noise was not sufficient to explain the observed kinetic behavior, but rather the importance of extrinsic noise has to be considered. Thus, distinct from gene expression in the examined signaling pathway fluctuations of the reaction rates has only a minor impact whereas variability in the concentration of the various signaling components even in a clonal cell population is a key determinant for the kinetic behavior.

Continuous light exposure causes cumulative stress that affects the localization oscillation dynamics of the transcription factor Msn2p.

Light exposure is a potentially powerful stress factor during in vivo optical microscopy studies. In yeast, the general transcription factor Msn2p translocates from the cytoplasm to the nucleus in response to illumination. However, previous time-lapse fluorescence microscopy studies of Msn2p have utilized a variety of discrete exposure settings, which makes it difficult to correlate stress levels and illumination parameters. We here investigate how continuous illumination with blue light, corresponding to GFP excitation wavelengths, affects the localization pattern of Msn2p-GFP in budding yeast. The localization pattern was analyzed using a novel approach that combines wavelet decomposition and change point analysis. It was found that the Msn2p nucleocytoplasmic localization trajectories for individual cells exhibit up to three distinct and successive states; i) Msn2p localizes to the cytoplasm; ii) Msn2p rapidly shuttles between the cytoplasm and the nucleus; iii) Msn2p localizes to the nucleus. Many cells pass through all states consecutively at high light intensities, while at lower light intensities most cells only reach states i) or ii). This behaviour strongly indicates that continuous light exposure gradually increases the stress level over time, presumably through continuous accumulation of toxic photoproducts, thereby forcing the cell through a bistable region corresponding to nucleocytoplasmic oscillations. We also show that the localization patterns are dependent on protein kinase A (PKA) activity, i.e. yeast cells with constantly low PKA activity showed a stronger stress response. In particular, the nucleocytoplasmic oscillation frequency was found to be significantly higher for cells with low PKA activity for all light intensities.

Brownian dynamics simulations in hydrogels using an adaptive time-stepping algorithm.

The adaptive time-stepping algorithm for Brownian simulation of solute diffusion in three-dimensional complex geometries previously developed by the authors of this paper was applied to heterogeneous three-dimensional polymer hydrogel structures. The simulations were performed on reconstructed three-dimensional hydrogels. The obstruction effect from the gel strands on water and diffusion of dendrimers with different sizes were determined by simulations and compared with experimental nuclear magnetic resonance diffusometry data obtained from the same material. It was concluded that obstruction alone cannot explain the observed diffusion rates, but an interaction between the dendrimers and the gel strands should be included in the simulations. The effect of a sticky-wall interaction potential with geometrically distributed residence times on the diffusion rate has been studied. It was found that sticky-wall interaction is a possible explanation for the discrepancy between simulated and experimental diffusion data for dendrimers of different sizes diffusing in hydrogels.

Image analysis algorithms for cell contour recognition in budding yeast.

Quantification of protein abundance and subcellular localization dynamics from fluorescence microscopy images is of high contemporary interest in cell and molecular biology. For large-scale studies of cell populations and for time-lapse studies, such quantitative analysis can not be performed effectively without some kind of automated image analysis tool. Here, we present fast algorithms for automatic cell contour recognition in bright field images, optimized to the model organism budding yeast (Saccharomyces cerevisiae). The cell contours can be used to effectively quantify cell morphology parameters as well as protein abundance and subcellular localization from overlaid fluorescence data.

Estimation of centres and radial intensity profiles of spherical nano-particles in digital microscopy.

Control of the microscopic characteristics of colloidal systems is critical in a wealth of application areas, ranging from food to pharmaceuticals. To assist in estimating these characteristics, we present a method for estimating the positions of spherical nano-particles in digital microscopy images. The radial intensity profiles of particles, which depend on the distances of the particles from the focal plane of the light microscope and have no closed functional form, are modelled using a local quadratic kernel estimate. We also allow for the case where pixel values are censored at an upper limit of 255. Standard errors of centre estimates are obtained using a sandwich estimator which takes into account spatial autocorrelation in the errors. The approach is validated by a simulation study.

Identification of the three-dimensional gel microstructure from transmission electron micrographs.

Mass transport in gels depends crucially on local properties of the gel network. We propose a method for identifying the three-dimensional (3D) gel microstructure from statistical information in transmission electron micrographs. The gel strand network is modelled as a random graph with nodes and edges (branches). The distribution of edge length, the number of edges at nodes and the angles between edges at a node are estimated from transmission electron micrographs by image analysis methods. The 3D network is simulated by Markov chain Monte Carlo, with a probability function based on the statistical information found from the micrographs. The micrographs are projections of stained gel strands in slices, and we derive a formula for estimating the thickness of the stained gel slice based on the total projected gel strand length and the number of times that gel strands enter or exit the slice.