Read by QxMD icon Read

Sialic Acid

N B Ustinov, E G Zavyalova, I G Smirnova, A M Kopylov
Influenza virus hemagglutinins (HAs) are surface proteins that bind to sialic acid residues at the host cell surface and ensure further virus internalization. Development of methods for the inhibition of these processes drives progress in the design of new antiviral drugs. The state of the isolated HA (i.e. combining tertiary structure and extent of oligomerization) is defined by multiple factors, like the HA source and purification method, posttranslational modifications, pH, etc. The HA state affects HA functional activity and significantly impacts the results of numerous HA assays...
November 2017: Biochemistry. Biokhimii︠a︡
Rachel A North, Christopher R Horne, James S Davies, Daniela M Remus, Andrew C Muscroft-Taylor, Parveen Goyal, Weixiao Yuan Wahlgren, S Ramaswamy, Rosmarie Friemann, Renwick C J Dobson
Eukaryotic cell surfaces are decorated with a complex array of glycoconjugates that are usually capped with sialic acids, a large family of over 50 structurally distinct nine-carbon amino sugars, the most common member of which is N-acetylneuraminic acid. Once made available through the action of neuraminidases, bacterial pathogens and commensals utilise host-derived sialic acid by degrading it for energy or repurposing the sialic acid onto their own cell surface to camouflage the bacterium from the immune system...
December 8, 2017: Biophysical Reviews
Hamid A Bakshi, Faruck Lukmanul Hakkim, Smitha Sam, Farideh Javid
Crocus sativus and its bioactive constituent crocin are well known for anti-tumor potential in different models. However, the efficacy of crocin on in-vivo melanoma metastasis is not yet reported. In this study, melanoma metastatic model was developed by tail vein injection of B16F-10 cells in to C57BL/6 mice. Metastatic mice treated with two different doses of crocin (250 and 500 µg/kg of bodyweight) for 10 days and parameters such as lung metastasis inhibition, mean survival time, lung hydroxyproline, uronic acid and hexosamine levels were analyzed after 21 days of treatment...
November 1, 2017: Journal of Biomedical Research
Sehkar Oktay, Gamze Bayrak, Burcin Alev, Hazal Ipekci, Unsal Veli Ustundag, Ismet Burcu Turkyilmaz, Rabia Pisiriciler, Ebru Emekli-Alturfan, Tugba Tunali-Akbay, Refiye Yanardag, Aysen Yarat
The aim of this study is to investigate the therapeutic effects of vitamin U (Vit U) on lung tissue of pentyleneterazole (PTZ)-induced seizures in rats. Sprague Dawley male rats were randomly divided into four groups as follows: control (0.9% NaCl given, intraperitoneally); Vit U (50 mg/kg/day, for 7 days by gavage); PTZ; (60 mg/kg one dose, intraperitoneally); and PTZ + Vit U (in same dose and time). At the end of the experiment, lung tissues were taken and examined biochemically and cytologically. Lipid peroxidation (LPO), glutathione (GSH), sialic acid (SA), and nitric oxide (NO) levels, and superoxide dismutase (SOD) and catalase (CAT) activities were determined in lung homogenates...
December 7, 2017: Naunyn-Schmiedeberg's Archives of Pharmacology
Cong Chen, Liguo Liu, Yan Xiao, Sheng Cui, Jianmin Wang, Qi Jin
Since its first emergence in East China in early 2013, many cases of avian influenza A H7N9 have been reported. The disease has extended to 22 provinces in mainland China and some surrounding areas. Strategies to combat viral infection are urgently needed. We previously isolated a human monoclonal antibody, HNIgGA6, that neutralized H7N9 virus both in vitro and in vivo. In this study, we determined the crystal structure of viral hemagglutinin (HA) globular head bound to the Fab fragment of HNIgGA6. The crystal structure shows that the tip of the HNIgGA6 heavy-chain complementarity determining region 3 (HCDR3) directly interposes into the receptor binding site (RBS) and mimics, in many respects, the interaction of the sialic acid receptor...
December 6, 2017: Journal of Virology
Yan-Cun Liu, Mu-Ming Yu, Yan-Fen Chai, Song-Tao Shou
Sialic acid-binding immunoglobulin-type lectins (Siglecs) are a group of cell surface transmembrane receptors expressed on immune cells, and regulate immune balance in inflammatory diseases. Sepsis is a life-threatened inflammatory syndrome induced by infection, and the pathogenesis of sepsis includes immune dysregulation, inflammation, and coagulation disorder. Here, we reviewed the various roles acted by Siglecs family in the pathogenesis of sepsis. Siglec-1, Siglec-5, and Siglec-14 play bidirectional roles through modulation of inflammation and immunity...
2017: Frontiers in Immunology
Sateesh Peri, Asmita Kulkarni, Felix Feyertag, Patricia M Berninsone, David Alvarez-Ponce
The enzyme CMP-N-acetylneuraminic acid hydroxylase (CMAH) is responsible for the synthesis of N-glycolylneuraminic acid (Neu5Gc), a sialic acid present on the cell surface proteins of most deuterostomes. The CMAH gene is thought to be present in most deuterostomes, but it has been inactivated in a number of lineages, including humans. The inability of humans to synthesize Neu5Gc has had several evolutionary and biomedical implications. Remarkably, Neu5Gc is a xenoantigen for humans, and consumption of Neu5Gc-containing foods, such as red meats, may promote inflammation, arthritis and cancer...
November 30, 2017: Genome Biology and Evolution
Huangxian Ju, Yunlong Chen, Huipu Liu, Yingying Xiong
This work proposes, for the first time, a screening strategy for nondestructive quantitation of gangliosides on cell surface with designed extractors and collectors. The extractors are constructed by functionalizing maleimide silica bubbles with DNA probe, which contains endonuclease cleavage site and boronic acid end to extract cell surface sialic acid-contained compounds through simple centrifugation. After the extractors containing extracted compounds are incubated with endonuclease, the released oligonucleotide-gangliosides can be selectively collected by silylanized collector bubbles via hydrophobic interaction...
December 4, 2017: Angewandte Chemie
Lester Thoo, Mochamad Z Fahmi, Ihsan N Zulkipli, Natasha Keasberry, Adi Idris
Carbon dot (Cdot) nanoparticles are an emerging class of carbon nanomaterials with a promising potential for drug delivery and bio imaging applications. Although the interaction between Cdots and non-immune cell types has been well studied, Cdot interactions with macrophages have not been investigated. Exposure of Cdot nanoparticles to J774.1 cells, a murine macrophage cell line, resulted in minimal toxicity, where notable toxicity was only seen with Cdot concentrations higher than 0.5 mg/ml. Flow cytometric analysis revealed that Cdots prepared from citric acid were internalized at significantly higher levels by macrophages compared with those prepared from bamboo leaves...
2017: Central-European Journal of Immunology
Jihong Li, Bruce A McClane
Enterotoxin-producing Clostridium perfringens type A strains cause human gastrointestinal (GI) infections, including a very common food poisoning and 5-10% of all antibiotic-associated diarrhea cases. This bacterium can utilize free sialic acid for growth but most sialic acids in the GI tract are sequestered on macromolecules such as the mucin proteins of mucus or glycoconjugates in host cells. However, many C. perfringens strains produce sialidases that might promote growth and survival by generating free sialic acid from those sialyated host macromolecules or by exposing underlying carbohydrates or proteins for digestion by other enzymes...
December 4, 2017: Infection and Immunity
Sepideh Rezaei-Adl, Arash Ghahroudi Tali, Hiva Saffar, Afsaneh Rajabiani, Alireza Abdollahi
 Due to a close link between cardiovascular disorders and increased acute phase responses, it is now proposed the relation of total sialic acid (TSA) and C Reactive Protein (CRP) as main components of acute phase proteins and cardiovascular risk profiles such as diabetes mellitus and smoking. We hypothesized that the elevation in the level of TSA along with other prototype acute phase reactants such as CRP is expected more in the coexistence of diabetes and smoking than in diabetes mellitus alone. Ninety diabetic patients were randomly selected and entered into this case-control study...
September 2017: Acta Medica Iranica
Keiji Tanigaki, Anastasia Sacharidou, Jun Peng, Ken L Chambliss, Ivan S Yuhanna, Debabrata Ghosh, Mohamed Ahmed, Alexander J Szalai, Wanpen Vongpatanasin, Robert F Mattrey, Qiushi Chen, Parastoo Azadi, Ildiko Lingvay, Marina Botto, William L Holland, Jennifer J Kohler, Shashank R Sirsi, Kenneth Hoyt, Philip W Shaul, Chieko Mineo
Type 2 diabetes mellitus (T2DM) is a common complication of obesity. Here, we have shown that activation of the IgG receptor FcγRIIB in endothelium by hyposialylated IgG plays an important role in obesity-induced insulin resistance. Despite becoming obese on a high-fat diet (HFD), mice lacking FcγRIIB globally or selectively in endothelium were protected from insulin resistance as a result of the preservation of insulin delivery to skeletal muscle and resulting maintenance of muscle glucose disposal. IgG transfer in IgG-deficient mice implicated IgG as the pathogenetic ligand for endothelial FcγRIIB in obesity-induced insulin resistance...
November 27, 2017: Journal of Clinical Investigation
Sing Yee Yeung, Annabell Mucha, Ravindra Deshmukh, Malak Boutrus, Thomas Arnebrant, Börje Sellergren
We report on the design of pH-switchable monolayers allowing a reversible and ordered introduction of affinity reagents on sensor surfaces. The principal layer building blocks consist of α-(4-amidinophenoxy)alkanes decorated at the ω-position with affinity ligands. These spontaneously self-assemble on top of carboxylic acid terminated SAMs to form reversible homo or mixed monolayers (rSAMs) that are tunable with respect to the nature of the head group, layer order and stability while featuring pH responsiveness and the dynamic nature of noncovalent build assemblies...
November 22, 2017: ACS Central Science
Takashi Suzuki
Sialidase releases sialic acid residues from the ends of sugar chains. The sialidases are involved in many physiological processes including cell differentiation and proliferation and immune function as well as pathophysiological conditions such as various human cancers and infections. Therefore visualization of sialidase activities with high sensitivity could provide valuable insights into these isozyme's activity. We developed novel fluorescent sialidase substrates, 2-benzothiazol-2-yl-phenol derivatives-based N-acetylneuraminic acid (Neu5Ac) (BTP-Neu5Ac) substrates, for highly sensitive and specific visualization of sialidase activity in living mammalian tissues and virus-infected cells...
2017: Biological & Pharmaceutical Bulletin
Mitsuru Tsuji, Nongluk Sriwilaijaroen, Hideo Inoue, Kazuhiko Miki, Kaoru Kinoshita, Kiyotaka Koyama, Kimio Furuhata, Yasuo Suzuki, Kunio Takahashi
We are interested in new non-natural glycosides with sialic acid conjugates and their biological activities. We report the synthesis of eleven non-natural occurring glycosides, which are triterpene (glycyrrhetinic acid and its derivatives)-sialic acid conjugates, and their inhibitory activities against influenza virus sialidases and influenza virus multiplication in MDCK host cells. Deoxoglycyrrhetol-sialic acid conjugates (6d and 6e) and oleanolic acid-sialic acid conjugates (7d and 7e) showed strong inhibitory activities against three subtypes of influenza virus sialidases...
October 3, 2017: Bioorganic & Medicinal Chemistry
Albert Barroso, Estela Giménez, Albert Konijnenberg, Jaime Sancho, Victoria Sanz-Nebot, Frank Sobott
The study of protein glycosylation can be regarded as an intricate but very important task, making glycomics one of the most challenging and interesting, albeit under-researched, type of "omics" science. Complexity escalates remarkably when considering that carbohydrates can form severely branched structures with many different constituents, which often leads to the formation of multiple isomers. In this regard, ion mobility (IM) spectrometry has recently demonstrated its power for the separation of isomeric compounds...
November 29, 2017: Journal of Proteomics
Asmi Chakraborty, Kaitlyn A Dorsett, Hoa Q Trummell, Eddy S Yang, Patsy G Oliver, James A Bonner, Donald J Buchsbaum, Susan L Bellis
Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with a poor prognosis. Gemcitabine, as a single agent or in combination therapy, remains the frontline chemotherapy despite its limited efficacy due to de novo or acquired chemoresistance. There is an acute need to decipher mechanisms underlying chemoresistance and identify new targets to improve patient outcomes. Here we report a novel role for the ST6Gal-I sialyltransferase in gemcitabine resistance. Utilizing MiaPaCa-2 and BxPC-3 PDAC cells, we find that knockdown (KD) of ST6Gal-I expression, as well as removal of surface α2-6 sialic acids by neuraminidase, enhances gemcitabine-mediated cell death assessed via colonogenic assays and cleaved caspase 3 expression...
November 30, 2017: Journal of Biological Chemistry
Jing-Bo Hu, Gui-Ling Song, Di Liu, Shu-Juan Li, Jia-Hui Wu, Xu-Qi Kang, Jing Qi, Fei-Yang Jin, Xiao-Juan Wang, Xiao-Ling Xu, Xiao-Ying Ying, Lian Yu, Jian You, Yong-Zhong Du
In an attempt to improve therapeutic efficacy of dexamethasone (DXM)-loaded solid lipid nanoparticles (NPs) for renal ischemia-reperfusion injury (IRI)-induced acute renal injury (AKI), sialic acid (SA) is used as a ligand to target the inflamed vascular endothelium. DXM-loaded SA-conjugated polyethylene glycol (PEG)ylated NPs (SA-NPs) are prepared via solvent diffusion method and show the good colloidal stability. SA-NPs reduce apoptotic human umbilical vein endothelial cells (HUVECs) via downregulating oxidative stress-induced Bax, upregulating Bcl-xL, and inhibiting Caspase-3 and Caspase-9 activation...
November 2017: Drug Delivery
Gege Xu, Matthew J Amicucci, Zhi Cheng, Ace G Galermo, Carlito B Lebrilla
A rapid method for the quantitation of sixteen neutral and acidic monosaccharides, from both animal and plant sources was developed using ultra-high performance liquid chromatography triple quadrupole mass spectrometry (UHPLC/QqQ-MS) in dynamic multiple reaction monitoring (dMRM) mode. Monosaccharides including three pentoses (ribose, xylose, arabinose), two deoxyhexoses (rhamnose, fucose), five hexoses (fructose, mannose, allose, glucose, galactose), two hexuronic acids (glucuronic acid, galacturonic acid), and two N-acetyl-hexosamines (GlcNAc, GalNAc), were derivatized with 1-phenyl-3-methyl-5-pyrazolone (PMP), while underivatized sialic acids, Neu5Ac and Neu5Gc, were simultaneously analyzed with a 10-minute run...
November 29, 2017: Analyst
Austin T Mudd, Stephen A Fleming, Beau Labhart, Maciej Chichlowski, Brian M Berg, Sharon M Donovan, Ryan N Dilger
Sialic acid (SA) is a key component of gangliosides and neural cell adhesion molecules important during neurodevelopment. Human milk contains SA in the form of sialyllactose (SL) an abundant oligosaccharide. To better understand the potential role of dietary SL on neurodevelopment, the effects of varying doses of dietary SL on brain SA content and neuroimaging markers of development were assessed in a newborn piglet model. Thirty-eight male pigs were provided one of four experimental diets from 2 to 32 days of age...
November 28, 2017: Nutrients
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"