671 research outputs found
Maternal obesity is associated with the formation of small dense LDL and hypoadiponectinemia in the third trimester
Context: Maternal obesity is associated with high plasma triglyceride, poor vascular function, and an increased risk for pregnancy complications. In normal-weight pregnant women, higher triglyceride is associated with increased small, dense low-density lipoprotein (LDL).
Hypothesis: In obese pregnancy, increased plasma triglyceride concentrations result in triglyceride enrichment of very low-density lipoprotein-1 particles and formation of small dense LDL via lipoprotein lipase.
Design: Women (n = 55) of body mass index of 18–46 kg/m2 were sampled longitudinally at 12, 26, and 35 weeks' gestation and 4 months postnatally.
Setting: Women were recruited at hospital antenatal appointments, and study visits were in a clinical research suite.
Outcome Measures: Plasma concentrations of lipids, triglyceride-rich lipoproteins, lipoprotein lipase mass, estradiol, steroid hormone binding globulin, insulin, glucose, leptin, and adiponectin were determined.
Results: Obese women commenced pregnancy with higher plasma triglyceride, reached the same maximum, and then returned to higher postnatal levels than normal-weight women. Estradiol response to pregnancy (trimester 1–3 incremental area under the curve) was positively associated with plasma triglyceride response (r2 adjusted 25%, P < .001). In the third trimester, the proportion of small, dense LDL was 2-fold higher in obese women than normal-weight women [mean (SD) 40.7 (18.8) vs 21.9 (10.9)%, P = .014], and 35% of obese, 14% of overweight, and none of the normal-weight women displayed an atherogenic LDL subfraction phenotype. The small, dense LDL mass response to pregnancy was inversely associated with adiponectin response (17%, P = .013).
Conclusions: Maternal obesity is associated with an atherogenic LDL subfraction phenotype and may provide a mechanistic link to poor vascular function and adverse pregnancy outcome
Electrophiles modulate glutathione reductase activity via alkylation and upregulation of glutathione biosynthesis
Cells evolved robust homeostatic mechanisms to protect against oxidation or alkylation by electrophilic species.
Glutathione (GSH) is the most abundant intracellular thiol, protects cellular components from oxidation and is
maintained in a reduced state by glutathione reductase (GR). Nitro oleic acid (NO2-OA) is an electrophilic fatty
acid formed under digestive and inflammatory conditions that both reacts with GSH and induces its synthesis
upon activation of Nrf2 signaling. The effects of NO2-OA on intracellular GSH homeostasis were evaluated. In
addition to upregulation of GSH biosynthesis, we observed that NO2-OA increased intracellular GSSG in an
oxidative stress-independent manner. NO2-OA directly inhibited GR in vitro by covalent modification of the
catalytic Cys61, with kon of (3.45±0.04)×103 M−1 s−1, koff of (4.4±0.4)×10−4 s−1, and Keq of
(1.3±0.1)×10−7 M. Akin to NO2-OA, the electrophilic Nrf2 activators bardoxolone-imidazole (CDDO-Im),
bardoxolone-methyl (CDDO-Me) and dimethyl fumarate (DMF) also upregulated GSH biosynthesis while promoting GSSG accumulation, but without directly inhibiting GR activity. In vitro assays in which GR was treated
with increasing GSH concentrations and GSH depletion experiments in cells revealed that GR activity is finely
regulated via product inhibition, an observation further supported by theoretical (kinetic modeling of cellular
GSSG:GSH levels) approaches. Together, these results describe two independent mechanisms by which electrophiles modulate the GSH/GSSG couple, and provide a novel conceptual framework to interpret experimentally determined values of GSH and GSSG
A FABP4-PPARγ signaling axis regulates human monocyte responses to electrophilic fatty acid nitroalkenes
Nitro-fatty acids (NO2-FA) are electrophilic lipid mediators derived from unsaturated fatty acid nitration. These species are produced endogenously by metabolic and inflammatory reactions and mediate anti-oxidative and anti-inflammatory responses. NO2-FA have been postulated as partial agonists of the Peroxisome Proliferator-Activated Receptor gamma (PPARγ), which is predominantly expressed in adipocytes and myeloid cells. Herein, we explored molecular and cellular events associated with PPARγ activation by NO2-FA in monocytes and macrophages. NO2-FA induced the expression of two PPARγ reporter genes, Fatty Acid Binding Protein 4 (FABP4) and the scavenger receptor CD36, at early stages of monocyte differentiation into macrophages. These responses were inhibited by the specific PPARγ inhibitor GW9662. Attenuated NO2-FA effects on PPARγ signaling were observed once cells were differentiated into macrophages, with a significant but lower FABP4 upregulation, and no induction of CD36. Using in vitro and in silico approaches, we demonstrated that NO2-FA bind to FABP4. Furthermore, the inhibition of monocyte FA binding by FABP4 diminished NO2-FA-induced upregulation of reporter genes that are transcriptionally regulated by PPARγ, Keap1/Nrf2 and HSF1, indicating that FABP4 inhibition mitigates NO2-FA signaling actions. Overall, our results affirm that NO2-FA activate PPARγ in monocytes and upregulate FABP4 expression, thus promoting a positive amplification loop for the downstream signaling actions of this mediator.Fil: Lamas Bervejillo, M.. Universidad de la República; UruguayFil: Bonanata, Julieta. Universidad de la República; UruguayFil: Franchini, Gisela Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner"; ArgentinaFil: Richeri, A.. Instituto de Investigaciones Biológicas "Clemente Estable"; UruguayFil: Marqués, J.M.. Universidad de la República; UruguayFil: Freeman, B.A.. University of Pittsburgh; Estados UnidosFil: Schopfer, Francisco Jose. University of Pittsburgh; Estados UnidosFil: Coitiño, E.L.. Universidad de la República; UruguayFil: Córsico, Betina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner"; ArgentinaFil: Rubbo, H.. Universidad de la República; UruguayFil: Ferreira, A.M.. Universidad de la República; Urugua
Electrophilic nitroalkene-tocopherol derivatives: synthesis, physicochemical characterization and evaluation of anti-inflammatory signaling responses
Inflammation plays a major role in the onset and development of chronic non-communicable diseases like obesity, cardiovascular diseases and cancer. Combined, these diseases represent the most common causes of death worldwide, thus development of novel pharmacological approaches is crucial. Electrophilic nitroalkenes derived from fatty acids are formed endogenously and exert anti-inflammatory actions by the modification of proteins involved in inflammation signaling cascades. We have developed novel nitroalkenes derived from α-tocopherol aiming to increase its salutary actions by adding anti-inflammatory properties to a well-known nutraceutical. We synthesized and characterized an α-tocopherol-nitroalkene (NATOH) and two hydrosoluble analogues derived from Trolox (NATxME and NATx0). We analyzed the kinetics of the Michael addition reaction of these compounds with thiols in micellar systems aiming to understand the effect of hydrophobic partition on the reactivity of nitroalkenes. We studied NATxME in vitro showing it exerts non-conventional anti-inflammatory responses by inducing Nrf2-Keap1-dependent gene expression and inhibiting the secretion of NF-κB dependent pro-inflammatory cytokines. NATxME was also effective in vivo, inhibiting neutrophil recruitment in a zebrafish model of inflammation. This work lays the foundation for the rational design of a new therapeutic strategy for the prevention and treatment of metabolic and inflammation-related disease
Highly deformed Ca configurations in Si + C
The possible occurrence of highly deformed configurations in the Ca
di-nuclear system formed in the Si + C reaction is investigated
by analyzing the spectra of emitted light charged particles. Both inclusive and
exclusive measurements of the heavy fragments (A 10) and their
associated light charged particles (protons and particles) have been
made at the IReS Strasbourg {\sc VIVITRON} Tandem facility at bombarding
energies of Si) = 112 MeV and 180 MeV by using the {\sc ICARE}
charged particle multidetector array. The energy spectra, velocity
distributions, and both in-plane and out-of-plane angular correlations of light
charged particles are compared to statistical-model calculations using a
consistent set of parameters with spin-dependent level densities. The analysis
suggests the onset of large nuclear deformation in Ca at high spin.Comment: 33 pages, 11 figure
Governance of microfinance institutions (MFIs) in Cameroon: What lessons can we learn?
The aim of this paper is to find out the effects of the COBAC regulations regulating the microfinance industry on the governance of microfinance institutions (MFIs) in Cameroon. The paper is based on 35 in-depth interviews carried out from May to June 2011 and June to July 2012 with managers and accountants from MFIs in Cameroon, MFI clients and non-clients, regulatory authorities in the Ministry of Finance, and accounting professionals. The findings show that the regulations have broken down the governance within the MFIs in Cameroon thus turning MFIs into hybrid organizations with managers striving to meet their shareholders' interests
Shrinking a large dataset to identify variables associated with increased risk of Plasmodium falciparum infection in Western Kenya
Large datasets are often not amenable to analysis using traditional single-step approaches. Here, our general objective was to apply imputation techniques, principal component analysis (PCA), elastic net and generalized linear models to a large dataset in a systematic approach to extract the most meaningful predictors for a health outcome. We extracted predictors for Plasmodium falciparum infection, from a large covariate dataset while facing limited numbers of observations, using data from the People, Animals, and their Zoonoses (PAZ) project to demonstrate these techniques: data collected from 415 homesteads in western Kenya, contained over 1500 variables that describe the health, environment, and social factors of the humans, livestock, and the homesteads in which they reside. The wide, sparse dataset was simplified to 42 predictors of P. falciparum malaria infection and wealth rankings were produced for all homesteads. The 42 predictors make biological sense and are supported by previous studies. This systematic data-mining approach we used would make many large datasets more manageable and informative for decision-making processes and health policy prioritization
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