Результаты поиска

[A not-previously described hereditary neurological disease with a deficiency of sialic acid, galactose and N-acetylglucosamine of plasma glycoproteins].

We report on five girls (including monozygotic twins) with a newly recognized disease comprising severe neurologic disturbances, variable hepatomegaly, abnormal subcutaneous fat distribution and skeletal anomalies. The neurologic picture was characterized by moderate to severe psychomotor retardation, alternating internal strabismus , hypotonia, hyporeflexia and ataxia. Biochemical investigations showed a number of abnormalities such as tubular proteinuria, slightly increased serum transaminases, hypoalbuminemia, hypo-beta-lipoproteinemia and decreased serum thyroxine-binding globulin. Moreove

Mass spectrometric analysis of intact lipooligosaccharide: direct evidence for O-acetylated sialic acids and discovery of O-linked glycine expressed by Campylobacter jejuni.

The lipooligosaccharides (LOS) of Campylobacter jejuni is an important virulence factor. Its core oligosaccharide component is frequently sialylated and bears a close resemblance with host gangliosides. The display of ganglioside mimics by this bacterium is believed to trigger the onset of the autoimmune condition Guillain-Barré syndrome (GBS) in some individuals. Considerable effort has been directed toward the structural characterization of the glycan component of the LOS of C. jejuni strains isolated from GBS patients. Capillary electrophoresis-mass spectrometry (CE-MS) has been a particula

Role of L-selectin on leukocytes in the binding of sialic acids on sperm surface during the phagocytosis of sperm in female reproductive tract.

In either natural fertilization or artificial insemination, hundreds of millions of sperm are ejaculated or inseminated and then deposited i … vely expressed on leukocytes, which can influence the behaviors of leukocytes when bind to ligands. Sialic acids are found as the outer most monosaccharide, capping the majority of glycans at the sperm surface, can act as recognition molecule. Since the sialic acids are considered as ligands of L-selectin, we propose that leukocytes bind to the sperm through t …

9-O-acetylated sialic acids differentiating normal haematopoietic precursors from leukemic stem cells with high aldehyde dehydrogenase activity in children with acute lymphoblastic leukaemia.

Childhood acute lymphoblastic leukaemia (ALL) originates from mutations in haematopoietic progenitor cells (HPCs). For high-risk patients, treated with intensified post-remission chemotherapy, haematopoietic stem cell (HSC) transplantation is considered. Autologous HSC transplantation needs improvisation till date. Previous studies established enhanced disease-associated expression of 9-O-acetylated sialoglycoproteins (Neu5,9Ac2-GPs) on lymphoblasts of these patients at diagnosis, followed by its decrease with clinical remission and reappearance with relapse. Based on this differential express

Инфекция глиальных клеток полиомавирусом человека JC происходит при помощи гликопротеина, связанного с N и содержащего сиалистические кислоты, связанные с конечной альфа(2-6).

Полиомавирус человека (JCV) является этиологическим агентом смертельной центральной нервной системы (CNS), демиелинизирующим заболевание прогрессивной многофукальной лейкоэнцефалопатии (PML). PML обычно встречается у иммуноподверженных пациентов и является прямым результатом заражения олигодендроцитами. Первичным явлением инфекции клеток JCV является соединение вируса с рецепторами, присутствующими на поверхности чувствительной клетки. Наша лаборатория изучает это критическое событие в жизненном цикле JCV, и мы обнаружили, что JCV связывается с ограниченным числом рецепторов поверхности клеток

Совпадение в аннотации оригинала
The human JC polyomavirus (JCV) is the etiologic agent of the fatal central nervous system (CNS) demyelinating disease progressive multifoca … e to inhibit infection correlated with its ability to remove both alpha(2-3)- and alpha(2-6)-linked sialic acids from glial cells. A recombinant neuraminidase that specifically removes the alpha(2-3) linkage of sialic acid had no effect on virus binding or infection. A competition assay between virus and sialic acid-specific lectins that recognize either the a …

Molecular and biochemical insights into dysregulation of glycosphingolipid metabolism in a mouse model of lysosomal free sialic acid storage disorder.

Free sialic acid storage disorder (FSASD) is caused by pathogenic biallelic variants in SLC17A5, which encodes the lysosomal sialic acid exporter, sialin. FSASD is characterized by the accumulation of lysosomal free sialic acid, leading to either a severe, childhood-lethal form or a more slowly progressive neurodegenerative disorder associated with the p.Arg39Cys (p.R39C) variant, i.e., Salla disease. While dysregulated glycosphingolipid (GSL) metabolism has been observed in cellular models of FSASD, this study provides the first in vivo biochemical dissection of GSL metabolism in a knock-in m

Programmable One-Tube Sialic Acid Derivatization Enables Dual-Mode N-Glycomics of Low-Input Samples.

Low-input glycomics remains particularly challenging for sialylated N-glycans because rigorous linkage-specific derivatization often increases sample handling, disperses signal across multiple linkage isomers, and compromises sensitivity. Here, we report a programmable one-tube workflow that integrates cell lysis, N-glycan release, sialic acid derivatization, and purification in a single microcentrifuge tube for highly sensitive N-glycome profiling. By controlling ammonia activity and reaction time after ethyl esterification, the workflow enables optional sialic acid linkage-specific, linkage-

Salivary sialic acid as a diagnostic biomarker for periodontal health in children with type 1 diabetes mellitus: a pilot study.

BACKGROUND: Type 1 Diabetes Mellitus (T1DM) is a chronic autoimmune condition that alters salivary composition due to metabolic disturbances. Saliva provides a non-invasive means of detecting systemic changes. This pilot study compared salivary pH, sialic acid concentration, antioxidant capacity, and oral health indicators between children with and without T1DM. METHODS: A comparative cross-sectional study was conducted among 40 children aged 6-15 years (20 with T1DM, 20 healthy controls). Sociodemographic and clinical data were collected, and unstimulated saliva was analysed for pH, sialic a

A smart pH-responsive and sialic acid targeted hybrid nanoparticles for precise chemo-herbal delivery in lung cancer.

Development of drug resistance, systemic toxicities, and treatment variability limit the translational use of nanocarriers (NCs) in lung cancer. A study utilized the successful synthesis of phenyl boronic acid-1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (PBA-DOPE) with pH responsiveness and precise sialic acid targeting characteristics. PBA-DOPE was surface anchored on lipid-polymer hybrid nanoparticles (PBA-DOPE HNPs) with a higher payload (>70%) of Biochanin-A (B) and Lenvatinib (L). A lipid shell polymer core nanostructure was defined and confirmed using photon correlation spectroscopy an

Loss of erythrocyte sialic acid in sepsis disrupts inhibitory Siglec interactions, driving neutrophil hyperactivation and NET outspread.

Systemic inflammation is accompanied by overwhelming neutrophil activation, resulting in extensive formation of neutrophil extracellular tra … essation of NET inhibition is due to inflammation-induced RBC desialylation (removal of α2,3-linked sialic acids) and decreased expression of inhibitory Siglec-E/9 and -G, but not Siglec-F/5, on neutrophils. Accordingly, concurrent addition of exogenous polysialic acid (PolySia) and pharmacologically controlled accumulation of Siglec molecules on neutrophils p …

Lysosomal free sialic acid storage disorder iPSC-derived neural cells display altered glycosphingolipid metabolism.

Lysosomal free sialic acid storage disorder (FSASD) is a rare neurodegenerative disease caused by biallelic mutations in SLC17A5, encoding the lysosomal sialic acid exporter, SLC17A5 (sialin). While the involvement of oligodendroglia in FSASD pathogenesis is established, the roles of other neural cell types remain elusive. In this study, we utilized radial glial cells (iRGCs), immature and mature astrocytes (iIAs and iMAs, respectively), and cortical neurons (iCNs) differentiated from induced pluripotent stem cells (iPSCs) derived from two individuals with FSASD, alongside two independent heal

The Role of the Hexosamine-Sialic Acid Metabolic Pathway Mediated by GFPT1/NANS in c-Myc-Driven Hepatocellular Carcinoma.

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) frequently involves metabolic reprogramming, which promotes oncogenesis and metastasis. However, the underlying molecular mechanisms remain insufficiently explored. In this study, we aim to investigate the metabolic abnormalities in c-Myc-driven HCC development and their potential therapeutic implications. METHODS: RNA sequencing and metabolomics were performed on HCC and adjacent tissues in a murine HCC model established by hydrodynamic tail-vein injection of c-Myc and sgTrp53/Cas9 plasmids. Key catalytic enzyme gene knockout was used to asse

Examining sialic acid derivatives as potential inhibitors of SARS-CoV-2 spike protein receptor binding domain.

Severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) has been the primary reason behind the COVID-19 global pandemic which has affected millions of lives worldwide. The fundamental cause of the infection is the molecular binding of the viral spike protein receptor binding domain (SP-RBD) with the human cell angiotensin-converting enzyme 2 (ACE2) receptor. The infection can be prevented if the binding of RBD-ACE2 is resisted by utilizing certain inhibitors or drugs that demonstrate strong binding affinity towards the SP RBD. Sialic acid based glycans found widely in human cells and tiss

Sialic acid blockade in dendritic cells enhances CD8+ T cell responses by facilitating high-avidity interactions.

Sialic acids are negatively charged carbohydrates that cap the glycans of glycoproteins and glycolipids. Sialic acids are involved in various biological processes including cell-cell adhesion and immune recognition. In dendritic cells (DCs), the major antigen-presenting cells of the immune system, sialic acids emerge as important regulators of maturation and interaction with other lymphocytes including T cells. Many aspects of how sialic acids regulate DC functions are not well understood and tools and model systems to address these are limited. Here, we have established cultures of murine bon…

Human-type sialic acid receptors contribute to avian influenza A virus binding and entry by hetero-multivalent interactions.

Establishment of zoonotic viruses, causing pandemics like the Spanish flu and Covid-19, requires adaptation to human receptors. Pandemic influenza A viruses (IAV) that crossed the avian-human species barrier switched from binding avian-type α2-3-linked sialic acid (2-3Sia) to human-type 2-6Sia receptors. Here, we show that this specificity switch is however less dichotomous as generally assumed. Binding and entry specificity were compared using mixed synthetic glycan gradients of 2-3Sia and 2-6Sia and by employing a genetically remodeled Sia repertoire on the surface of a Sia-free cell line an

Sialic Acid Protects Nontypeable Haemophilus influenzae from Natural IgM and Promotes Survival in Murine Respiratory Tract.

Nontypeable Haemophilus influenzae (NTHi), a common inhabitant of the human nasopharynx and upper airways, causes opportunistic respiratory tract infections that are frequently recurring and chronic. NTHi utilizes sialic acid from the host to evade antibacterial defenses and persist in mucosal tissues; however, the role of sialic acid scavenged by NTHi during infection is not fully understood. We previously showed that sialylation protects specific epitopes on NTHi lipooligosaccharide (LOS) targeted by bactericidal IgM in normal human serum. Here, we evaluated the importance of immune evasion

Prediction of Single Point Mutations in Human Coronavirus and Their Effects on Binding to 9-O-Acetylated Sialic Acid and Hidroxychloroquine.

Due to the current spreading of the new disease CoViD-19, the World Health Organization formally declared a world pandemic on March 11, 2020. The present trends indicate that the pandemic will have an enormous clinical and economic impact on population health. Infections are initiated by the transmembrane spike (S) glycoproteins of human coronavirus (hCoV) binding to host receptors. Ongoing research and therapeutic product development are of vital importance for the successful treatment of CoViD-19. To contribute somewhat to the overall effort, herein, single point mutations (SPMs) of the bind

Status of oxidative stress, trace elements, sialic acid and cholinesterase activity in cattle naturally infected with Babesia bigemina.

Babesia bigemina infection (also known as Texas fever) is reported as the most prevalent and main causative agent of bovine babesiosis, worldwide. The current study was undertaken to assess indicators of oxidative stress including activities of antioxidant enzymes and total antioxidant capacity (TAC), oxidation status of biomolecules and serum levels of trace elements as well as indicators of inflammation including sialic acid (SA) contents and cholinesterase activity in cattle naturally infected with B. bigemina. An infected group comprised of 20 crossbred Holstein cattle (3-4 years old) were

Cervical mucus sialic acid content determines the ability of frozen-thawed ram sperm to migrate through the cervix.

The aim of this study was to investigate the properties and to functionally characterize the cervical mucus that modulates sperm transport through the cervix by using ewe breeds with a divergent pregnancy rate (Belclare and Suffolk; high and low, respectively) following cervical insemination using frozen-thawed semen. Sperm number, as well as sialic acid and fucose content in both the channels and in the lumen of different regions of the cervix were quantified in inseminated Belclare and Suffolk ewes. Expression of glycosyltransferase and MUC genes, glycosidase activity and sialic acid speciat