Search results for "acids"
showing 10 items of 3520 documents
Abundance and δ13C values of fatty acids in lacustrine surface sediments: Relationships with in-lake methane concentrations
2018
Proxy-indicators in lake sediments provide the only approach by which the dynamics of in-lake methane cycling can be examined on multi-decadal to centennial time scales. This information is necessary to constrain how lacustrine methane production, oxidation and emissions are expected to respond to global change drivers. Several of the available proxies for reconstructing methane cycle changes of lakes rely on interpreting past changes in the abundance or relevance of methane oxidizing bacteria (MOB), either directly (e.g. via analysis of bacterial lipids) or indirectly (e.g. via reconstructions of the past relevance of MOB in invertebrate diet). However, only limited information is availabl…
Cholesterol trafficking and raft-like membrane domain composition mediate scavenger receptor class B type 1-dependent lipid sensing in intestinal epi…
2018
IF 5.547; International audience; Scavenger receptor Class B type 1 (SR-B1) is a lipid transporter and sensor. In intestinal epithelial cells, SR-B1-dependent lipid sensing is associated with SR-B1 recruitment in raft-like/ detergent-resistant membrane domains and interaction of its C-terminal transmembrane domain with plasma membrane cholesterol. To clarify the initiating events occurring during lipid sensing by SR-B1, we analyzed cholesterol trafficking and raft-like domain composition in intestinal epithelial cells expressing wild-type SR-B1 or the mutated form SR-B1-Q445A, defective in membrane cholesterol binding and signal initiation. These features of SR-B1 were found to influence bo…
Friedreich Ataxia: current state-of-the-art, and future prospects for mitochondrial-focused therapies
2021
Friedreichs Ataxia is an autosomal recessive genetic disease causing the defective gene product, frataxin. A body of literature has been focused on the attempts to counteract frataxin deficiency and the consequent iron imbalance, in order to mitigate the disease-associated prooxidant state and clinical course. The present mini review is aimed at evaluating the basic and clinical reports on the roles and the use of a set of iron chelators, antioxidants and some cofactors involved in the key mitochondrial functions. Extensive literature has focused on the protective roles of iron chelators, coenzyme Q10 and analogs, and vitamin E, altogether with varying outcomes in clinical studies. Other st…
On-demand autophagic network adaptations upon limited lipid availability
2020
The de novo synthesis of autophagic vesicles is strongly dependent on sufficient lipid supply. Recently, the RAB GTPase RAB18 was shown to affect autophagy by mediating fatty acid release from lipid droplets, which are lipid sources for autophagosome formation. The stable loss of RAB18 interfered with fatty acid release from the lipid reservoirs and provoked autophagy network adaptations aiming to maintain autophagic activity under lipid limiting conditions.
Identification and Characterization of a Single High-Affinity Fatty Acid Binding Site in Human Serum Albumin.
2017
A single high-affinity fatty acid binding site in the important human transport protein serum albumin (HSA) is identified and characterized using an NBD (7-nitrobenz-2-oxa-1,3-diazol-4-yl)-C12 fatty acid. This ligand exhibits a 1:1 binding stoichiometry in its HSA complex with high site-specificity. The complex dissociation constant is determined by titration experiments as well as radioactive equilibrium dialysis. Competition experiments with the known HSA-binding drugs warfarin and ibuprofen confirm the new binding site to be different from Sudlow-sites I and II. These binding studies are extended to other albumin binders and fatty acid derivatives. Furthermore an X-ray crystal structure …
DNA Methylation and Potential for Epigenetic Regulation in Pygospio elegans.
2015
Transitions in developmental mode are common evolutionarily, but how and why they occur is not understood. Developmental mode describes larval phenotypes, including morphology, ecology and behavior of larvae, which typically are generalized across different species. The polychaete worm Pygospio elegans is one of few species polymorphic in developmental mode, with multiple larval phenotypes, providing a possibility to examine the potential mechanisms allowing transitions in developmental mode. We investigated the presence of DNA methylation in P. elegans, and, since maternal provisioning is a key factor determining eventual larval phenotype, we compared patterns of DNA methylation in females…
Cardiolipin synthesis in brown and beige fat mitochondria is essential for systemic energy homeostasis
2018
Summary Activation of energy expenditure in thermogenic fat is a promising strategy to improve metabolic health, yet the dynamic processes that evoke this response are poorly understood. Here we show that synthesis of the mitochondrial phospholipid cardiolipin is indispensable for stimulating and sustaining thermogenic fat function. Cardiolipin biosynthesis is robustly induced in brown and beige adipose upon cold exposure. Mimicking this response through overexpression of cardiolipin synthase (Crls1) enhances energy consumption in mouse and human adipocytes. Crls1 deficiency in thermogenic adipocytes diminishes inducible mitochondrial uncoupling and elicits a nuclear transcriptional respons…
Cell type specific impact of cannabinoid receptor signaling in somatosensory barrel map formation in mice
2019
Endocannabinoids and their receptors are highly abundant in the developing cerebral cortex and play major roles in early developmental processes, for example, neuronal proliferation, migration, and axonal guidance as well as postnatal plasticity. To investigate the role of the cannabinoid type 1 receptor (CB1) in the formation of sensory maps in the cerebral cortex, the topographic representation of the whiskers in the primary somatosensory cortex (barrel field) of adult mice with different cell type specific genetic deletion of CB1 was studied. A constitutive absence of CB1 (CB1-KO) significantly decreased the total area of the somatosensory cortical map, affecting barrel, and septal areas…
Double methylation of tRNA-U54 to 2′-O-methylthymidine (Tm) synergistically decreases immune response by Toll-like receptor 7
2018
Abstract Sensing of nucleic acids for molecular discrimination between self and non-self is a challenging task for the innate immune system. RNA acts as a potent stimulus for pattern recognition receptors including in particular human Toll-like receptor 7 (TLR7). Certain RNA modifications limit potentially harmful self-recognition of endogenous RNA. Previous studies had identified the 2′-O-methylation of guanosine 18 (Gm18) within tRNAs as an antagonist of TLR7 leading to an impaired immune response. However, human tRNALys3 was non-stimulatory despite lacking Gm18. To identify the underlying molecular principle, interferon responses of human peripheral blood mononuclear cells to differentia…
Serum Amino Acid Profiles in Childhood Predict Triglyceride Level in Adulthood: A 7-Year Longitudinal Study in Girls.
2016
AbstractContext:Branched-chain and aromatic amino acids are associated with high risk of developing dyslipidemia and type II diabetes in adults.Objective:This study aimed to examine whether serum amino acid profiles associate with triglyceride concentrations during pubertal growth and predict hypertriglyceridemia in early adulthood.Design:This was a 7.5-year longitudinal study.Setting:The study was conducted at the Health Science Laboratory, University of Jyväskylä.Participants:A total of 396 nondiabetic Finnish girls aged 11.2 ± 0.8 years at the baseline participated in the study.Main Outcome Measures:Body composition was assessed by dual-energy x-ray absorptiometry; serum concentrations o…