Search results for "Peptides"
showing 10 items of 2897 documents
Brain Control of Plasma Cholesterol Involves Polysialic Acid Molecules in the Hypothalamus
2017
IF 3.566; International audience; The polysialic acid (PSA) is a large glycan that is added to cell-surface proteins during their post-translational maturation. In the brain, PSA modulates distances between cells and controls the plasticity of the nervous system. In the hypothalamus, PSA is involved in many aspects of energy balance including food intake, osmoregulation, circadian rhythm, and sleep. In this work, we investigated the role of hypothalamic PSA in the regulation of plasma cholesterol levels and distribution. We report that HFD consumption in mice rapidly increased plasma cholesterol, including VLDL, LDL, and HDL-cholesterol. Although plasma VLDL-cholesterol was normalized withi…
Rescue of Hypovitaminosis A Induces Non-Amyloidogenic Amyloid Precursor Protein (APP) Processing.
2015
Retinoic acid, the bioactive metabolite of beta-carotene or vitamin A, plays a pleiotropic, multifunctional role in vertebrate development. Studies in rodents revealed that a diet deficient in vitamin A results in a complex neonatal syndrome (the VAD syndrome), manifested in many organs. In humans, the function of retinoic acid (RA) extends into adulthood, where it has important roles in fertility, vision, and suppression of neoplastic growth. In recent years, it has also been suggested that retinoic acid might potentially act as a therapeutically relevant drug in attenuating or even preventing neurodegenerative diseases such as Alzheimer's disease (AD). Here, we report that VAD leads to an…
Interaction of C 60 fullerenes with asymmetric and curved lipid membranes: a molecular dynamics study
2015
Interaction of fullerenes with asymmetric and curved DOPC/DOPS bicelles is studied by means of coarse-grained molecular dynamics simulations. The effects caused by asymmetric lipid composition of the membrane leaflets and the curvature of the membrane are analyzed. It is shown that the aggregates of fullerenes prefer to penetrate into the membrane in the regions of the moderately positive mean curvature. Upon penetration into the hydrophobic core of the membrane fullerenes avoid the regions of the extreme positive or the negative curvature. Fullerenes increase the ordering of lipid tails, which are in direct contact with them, but do not influence other lipids significantly. Our data sugges…
Food quality affects the expression of antimicrobial peptide genes upon simulated parasite attack in the larvae of greater wax moth
2017
Predator‐prey interactions are an important evolutionary force affecting the immunity of the prey. Parasitoids and mites pierce the cuticle of their prey, which respond by activating their immune system against predatory attacks. Immunity is a costly function for the organism, as it often competes with other life‐history traits for limited nutrients. We tested whether the expression of antimicrobial peptides (AMP) of the larvae of the greater wax moth Galleria mellonella (L.) (Lepidoptera: Pyralidae) changes as a consequence of insertion of a nylon monofilament, which acts like a synthetic parasite. The treatment was done for larvae grown on a high‐quality vs. a low‐quality diet. The expres…
Mediterranean Diet Improves High-Density Lipoprotein Function in High-Cardiovascular-Risk Individuals: A Randomized Controlled Trial.
2017
Background: The biological functions of high-density lipoproteins (HDLs) contribute to explaining the cardioprotective role of the lipoprotein beyond quantitative HDL cholesterol levels. A few small-scale interventions with a single antioxidant have improved some HDL functions. However, to date, no long-term, large-scale, randomized controlled trial has been conducted to assess the effects of an antioxidant-rich dietary pattern (such as a traditional Mediterranean diet [TMD]) on HDL function in humans. Methods: This study was performed in a random subsample of volunteers from the PREDIMED Study (Prevención con Dieta Mediterránea; n=296) after a 1-year intervention. We compared the effects …
AC‐1001 H3 CDR peptide induces apoptosis and signs of autophagy in vitro and exhibits antimetastatic activity in a syngeneic melanoma model
2016
Antibody-derived peptides modulate functions of the immune system and are a source of anti-infective and antitumor substances. Recent studies have shown that they comprise amino acid sequences of immunoglobulin complementarity-determining regions, but also fragments of constant regions. VH CDR3 of murine mAb AC-1001 displays antimetastatic activities using B16F10-Nex2 murine melanoma cells in a syngeneic model. The peptide was cytotoxic in vitro in murine and human melanoma cells inducing reactive oxygen species (ROS) and apoptosis by the intrinsic pathway. Signs of autophagy were also suggested by the increased expression of LC3/LC3II and Beclin 1 and by ultrastructural evidence. AC-1001 H…
Statins in liver disease: not only prevention of cardiovascular events
2018
Statins are lipid-lowering agents and one of the most pre-scribed drugs worldwide. Their main mechanism of action –inhibition of the mevalonate pathway through an effect on hydroxy-methylglutaryl CoA reductase, thus affecting the synthesis of cholesterol in the liver – makes this class of drugs pivotal in primary and secondary prevention of cardio-vascular risk, as extensively demonstrated in large prospective, randomized controlled trials. Along the years, we learned that the lower the better, and LDL-cholesterol targets have been progressively reduced to values ≤70 mg/dL for secondary prevention or in the presence of diabetes.
Acetobacter musti sp. nov., isolated from Bobal grape must
2016
An acetic acid bacterium (strain Bo7T), obtained during a study of the microbial diversity of spontaneous fermentations of Bobal grape must, was subjected to a taxonomic study using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences allocated strain Bo7T to the genus Acetobacter, and revealed Acetobacter aceti and Acetobacter oeni to be nearest neighbours (99.57 % 16S rRNA gene sequence similarity between strain Bo7T and A. oeni CECT 5830T, and 98.76 % between strain Bo7T and A. aceti CECT 298T). Cells of strain Bo7T are Gram-negative, motile rods, catalase-positive and oxidase-negative. The DNA G+C content of strain Bo7T was 58.0 mol%. DNA–DNA hybridizations demo…
Annelid Coelomic Fluid Proteins
2020
The coelomic cavity is part of the main body plan of annelids. This fluid filled space takes up a considerable volume of the body and serves as an important site of exchange of both metabolites and proteins. In addition to low molecular substances such as amino acids and glucose and lactate, the coelomic fluid contains different proteins that can arise through release from adjacent tissues (intestine) or from secretion by coelomic cells. In this chapter, we will review the current knowledge about the proteins in the annelid coelomic fluid. Given the number of more than 20,000 extant annelid species, existing studies are confined to a relatively few species. Most studies on the oligochaetes …
Antimicrobial peptide–metal ion interactions – a potential way of activity enhancement
2018
Increasing bacterial and fungal drug resistance requires novel, effective antimicrobial treatments to be actively sought. Because of a general lack of resistance towards antimicrobial peptides (AMPs), they are being relied on as a novel class of therapeutics aiming to conquer drug-resistant bacteria and fungi. There are numerous ways in which AMPs might interact with pathogens, such as membrane disruption, production of ROS, inhibition of cell wall, nucleic acid and protein synthesis or by the withdrawal of essential metal ions. Biologically indispensable metal ions have a dual effect on the activity of antimicrobial peptides: (i) AMPs bind them, so that microbes cannot get enough metals es…