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O-glcnac aging

Willayat Y Wani, John C Chatham, Victor Darley-Usmar, Lori L McMahon, Jianhua Zhang
O-GlcNAcylation is a dynamic form of protein glycosylation which involves the addition of β-D-N-acetylglucosamine (GlcNAc) via an O-linkage to serine or threonine residues of nuclear, cytoplasmic, mitochondrial and transmembrane proteins. The two enzymes responsible for O-GlcNAc cycling are O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA); their expression and activities in brain are age dependent. More than 1000 O-GlcNAc protein targets have been identified which play critical roles in many cellular processes...
August 4, 2016: Brain Research Bulletin
Seçkin Soya, Umut Şahar, Sabire Karaçalı
Glycoconjugates have various functions in differentiation, development, aging and in all aspects of normal functioning of organisms. The reason for increased research on this topic is that glycoconjugates locate mostly on the cell surface and play crucial biological roles in the nervous system including brain development, synaptic plasticity, learning, and memory. Considering their roles in the nervous system, information about their existence in the insect nervous system is rather sparse. Therefore, in order to detect monosaccharide content of N- and O-glycans, we carried out capLC-ESI-MS/MS analysis to determine the concentration changes of glucose, mannose, galactose, N-acetylglucosamine (GlcNAc), N-acetylgalactosamine (GalNAc), fucose, xylose, arabinose, and ribose monosaccharides in the nervous system of Bombyx mori during development and aging processes...
September 2016: Invertebrate Neuroscience: IN
Partha S Banerjee, Olof Lagerlöf, Gerald W Hart
O-GlcNAcylation, a dynamic nutrient and stress sensitive post-translational modification, occurs on myriad proteins in the cell nucleus, cytoplasm and mitochondria. O-GlcNAcylation serves as a nutrient sensor to regulate signaling, transcription, translation, cell division, metabolism, and stress sensitivity in all cells. Aberrant protein O-GlcNAcylation plays a critical role both in the development, as well as in the progression of a variety of age related diseases. O-GlcNAcylation underlies the etiology of diabetes, and changes in specific protein O-GlcNAc levels and sites are responsible for insulin expression and sensitivity and glucose toxicity...
October 2016: Molecular Aspects of Medicine
Dorit Bennmann, Wenke Weidemann, Annett Thate, Denise Kreuzmann, Rüdiger Horstkorte
UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) is the key enzyme for the biosynthesis of sialic acids. Sialic acids are terminal monosaccharides of glycoconjugates and gangliosides, which have an essential influence on various cell interactions. The sialylation of proteins varies during development, aging, and pathogenesis of degenerative diseases such as Morbus Alzheimer, diabetes mellitus type II, or myopathies. Mutation of methionine 743 in the GNE leads to a 30% reduction of the enzyme activity and is responsible for an aggressive form of GNE myopathy...
June 2016: FEBS Journal
Eleonora Gatta, Tony Lefebvre, Silvana Gaetani, Marc dos Santos, Jordan Marrocco, Anne-Marie Mir, Tommaso Cassano, Stefania Maccari, Ferdinando Nicoletti, Jérôme Mairesse
Intracellular accumulation of hyperphosphorylated tau protein is linked to neuronal degeneration in Alzheimer's disease (AD). Mounting evidence suggests that tau phosphorylation and O-N-acetylglucosamine glycosylation (O-GlcNAcylation) are mutually exclusive post-translational modifications. O-GlcNAcylation depends on 3-5% of intracellular glucose that enters the hexosamine biosynthetic pathway. To our knowledge, the existence of an imbalance between tau phosphorylation and O-GlcNAcylation has not been reported in animal models of AD, as yet...
March 2016: Pharmacological Research: the Official Journal of the Italian Pharmacological Society
Guo Dong Liu, Chong Xu, Le Feng, Fang Wang
It has recently been reported that O-linked β-N-acetyl glucosamine (O-GlcNAc) modification (a simple intracellular serine (Ser)/threonine (Thr)-linked monosaccharide) in human retinal microvascular endothelial cells (HRECs) is related to diabetic retinopathy (DR). During O-GlcNAcylation, O-GlcNAc is added to Ser and Thr residues. As the generation of reactive oxygen species (ROS) is one of the characteristics of advanced glycation end product (AGE) injury, and the most important key pathogenic factor of DR, in the present study, we aimed to investigate the association between O-GlcNAcylation and ROS generation in order to ascertain whether O-GlcNAcylation mitigates cellular injury through the generation of ROS...
October 2015: International Journal of Molecular Medicine
Tony Lefebvre, Tarik Issad
No abstract text is available yet for this article.
2015: Frontiers in Endocrinology
Patricia Nagnan-Le Meillour, Anne-Sophie Vercoutter-Edouart, Frédérique Hilliou, Chrystelle Le Danvic, Frédéric Lévy
The diversity of olfactory binding proteins (OBPs) is a key point to understand their role in molecular olfaction. Since only few different sequences were characterized in each mammalian species, they have been considered as passive carriers of odors and pheromones. We have explored the soluble proteome of pig nasal mucus, taking benefit of the powerful tools of proteomics. Combining two-dimensional electrophoresis, mass spectrometry, and western-blot with specific antibodies, our analyses revealed for the first time that the pig nasal mucus is mainly composed of secreted OBP isoforms, some of them being potentially modified by O-GlcNAcylation...
2014: Frontiers in Endocrinology
Gerald W Hart
Even though the dynamic modification of polypeptides by the monosaccharide, O-linked N-acetylglucosamine (O-GlcNAcylation) was discovered over 30 years ago, its physiological significance as a major nutrient sensor that regulates myriad cellular processes has only recently been more widely appreciated. O-GlcNAcylation, either on its own or by its interplay with other post-translational modifications, such as phosphorylation, ubiquitination, and others, modulates the activities of signaling proteins, regulates most components of the transcription machinery, affects cell cycle progression and regulates the targeting/turnover or functions of myriad other regulatory proteins, in response to nutrients...
2014: Frontiers in Endocrinology
Alexis K Nagel, Lauren E Ball
O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA) catalyze the dynamic cycling of intracellular, post-translational O-GlcNAc modification on thousands of Ser/Thr residues of cytosolic, nuclear, and mitochondrial signaling proteins. The identification of O-GlcNAc modified substrates has revealed a functionally diverse set of proteins, and the extent of O-GlcNAcylation fluctuates in response to nutrients and cellular stress. As a result, OGT and OGA are implicated in widespread, nutrient-responsive regulation of numerous signaling pathways and transcriptional programs...
October 2014: Amino Acids
Lin Zhao, Zhihui Feng, Xuan Zou, Ke Cao, Jie Xu, Jiankang Liu
Retina is particularly susceptible to aging as oxidative damage accumulates within retina, leading to age-related retinal dysfunction or even visual loss. However, the underlying mechanisms still remain obscure and effective therapeutic strategy is urgently in need. Here, we quested for the answer particularly focusing on mitochondrial homeostasis and O-GlcNAcylation in rat retina. By comparing expression of electron transfer chain complexes and key factors in mitochondrial biogenesis and dynamics in retinas of aged and young Sprague-Dawley rats, we found that mitochondrial Complex I, II, IV and V were increased in aged retina with decreased mtTFA and Mfn2...
2014: Oxidative Medicine and Cellular Longevity
Sarah Förster, Andrew S Welleford, Judy C Triplett, Rukhsana Sultana, Brigitte Schmitz, D Allan Butterfield
The potential role of the posttranslational modification of proteins with O-linked N-acetyl-β-d-glucosamine (O-GlcNAc) in the pathogenesis of Alzheimer disease (AD) has been studied extensively, yet the exact function of O-GlcNAc in AD remains elusive. O-GlcNAc cycling is facilitated by only two highly conserved enzymes: O-GlcNAc transferase (OGT) catalyzes the addition, while O-GlcNAcase (OGA) catalyzes the removal of GlcNAc from proteins. Studies analyzing global O-GlcNAc levels in AD brain have produced inconsistent results and the reasons for altered O-GlcNAcylation in AD are still poorly understood...
September 2014: Biochimica et Biophysica Acta
S Park, J Pak, I Jang, J W Cho
Autophagy regulates cellular homeostasis through degradation of aged or damaged subcellular organelles and components. Interestingly, autophagy-deficient beta cells, for example Atg7-mutant mice, exhibited hypoinsulinemia and hyperglycemia. Also, autophagy response is diminished in heart of diabetic mice. These results implied that autophagy and diabetes are closely connected and affect each other. Although protein O-GlcNAcylation is up-regulated in hyperglycemia and diabetes, and O-GlcNAcylated proteins play an important role in metabolism and nutrient sensing, little is known whether autophagy affects O-GlcNAc modification and vice versa...
October 17, 2014: Biochemical and Biophysical Research Communications
Scott A Yuzwa, David J Vocadlo
Alzheimer disease (AD) is a growing problem for aging populations worldwide. Despite significant efforts, no therapeutics are available that stop or slow progression of AD, which has driven interest in the basic causes of AD and the search for new therapeutic strategies. Longitudinal studies have clarified that defects in glucose metabolism occur in patients exhibiting Mild Cognitive Impairment (MCI) and glucose hypometabolism is an early pathological change within AD brain. Further, type 2 diabetes mellitus (T2DM) is a strong risk factor for the development of AD...
October 7, 2014: Chemical Society Reviews
John A Hanover, Peng Wang
C. elegans has proven to be an excellent organism in which to model human neurodegenerative disease.(1) (-) (7) The worm's simple nervous system, lineage, and neural maps, easily scored movement phenotypes, and robust forward and reverse genetics make it optimal for studying age-dependent processes on a reasonable time scale. A popular approach has been the introduction of transgenes expressing GFP-tagged proteotoxic human proteins into neurons leading to visible aggregation or movement phenotypes.(2) (,) (4) (,) (6) (,) (8) (-) (13) In addition, the maintenance of proteostasis networks has been extensively studied using the power of worm genetics...
October 1, 2013: Worm
Kimberley M Mellor, Margaret A Brimble, Lea M D Delbridge
Diabetes elicits cardiac metabolic stress involving impaired glucose uptake and metabolic substrate shifts. Diabetic cardiac pathology is well documented in human patients and experimental animal models to be characterized by diastolic dysfunction, but the underlying mechanisms are not well understood. Signaling disturbances involved in cardiac insulin resistance are linked to glucose handling abnormalities. Both reversible (e.g. O-GlcNAc) and irreversible (e.g. AGEs) glucose-modifications of cardiomyocyte extracellular and intracellular proteins are implicated in structural and functional alterations underlying pathology in the diabetic heart...
May 15, 2015: Life Sciences
E P Smorodin, B L Sergeyev, O A Kurtenkov
UNLABELLED: The elevated anti-GalNAcβ IgG level of serum was shown to be associated with the significantly better survival of patients with gastrointestinal cancer. AIM: To characterize the specificity of IgG antibodies to GalNAcβ-terminated glycans of long-term gastric cancer survivors. METHODS: Serum antibodies and affinity-isolated antibodies were analysed by the indirect and competitive ELISA using glycan-polyacrylamide (PAA) conjugates as well as by isoelectric focusing and Western blotting...
March 2014: Experimental Oncology
Caroline Cieniewski-Bernard, Erwan Dupont, Elodie Richard, Bruno Bastide
Although calcium is the major regulator of excitation-contraction coupling, myofilament function can also be modulated through post-translational modifications. In particular, phosphorylation and O-GlcNAcylation are key modulators of calcium activation parameters. Among the regulatory proteins of skeletal muscle contraction, the myosin light chain 2 (MLC2) can undergo both types of post-translational modification. During aging or physical inactivity, the phosphorylation status of the slow isoform of MLC2 (sMLC2) does not correlate with calcium sensitivity, suggesting that the O-GlcNAcylation might modulate sMLC2 activity...
November 2014: Pflügers Archiv: European Journal of Physiology
Erica W Taylor, Kai Wang, Amy R Nelson, Teruko M Bredemann, Kyle B Fraser, Sarah M Clinton, Rosemary Puckett, Richard B Marchase, John C Chatham, Lori L McMahon
Serine phosphorylation of AMPA receptor (AMPAR) subunits GluA1 and GluA2 modulates AMPAR trafficking during long-term changes in strength of hippocampal excitatory transmission required for normal learning and memory. The post-translational addition and removal of O-linked β-N-acetylglucosamine (O-GlcNAc) also occurs on serine residues. This, together with the high expression of the enzymes O-GlcNAc transferase (OGT) and β-N-acetylglucosamindase (O-GlcNAcase), suggests a potential role for O-GlcNAcylation in modifying synaptic efficacy and cognition...
January 1, 2014: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Peter Borghgraef, Clément Menuet, Clara Theunis, Justin V Louis, Herman Devijver, Hervé Maurin, Caroline Smet-Nocca, Guy Lippens, Gerard Hilaire, Harrie Gijsen, Dieder Moechars, Fred Van Leuven
The microtubule associated protein tau causes primary and secondary tauopathies by unknown molecular mechanisms. Post-translational O-GlcNAc-ylation of brain proteins was demonstrated here to be beneficial for Tau.P301L mice by pharmacological inhibition of O-GlcNAc-ase. Chronic treatment of ageing Tau.P301L mice mitigated their loss in body-weight and improved their motor deficits, while the survival was 3-fold higher at the pre-fixed study endpoint at age 9.5 months. Moreover, O-GlcNAc-ase inhibition significantly improved the breathing parameters of Tau...
2013: PloS One
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