Novel glycan-related biomarker discovery by total glycomic and focused protein glycomic analyses.

The cell surface is covered with a variety of glycan subtypes (sub-glycans) such as N-glycans, O-glycans, glycosphingolipid-glycans, and glycosaminoglycans, which are collectively called the glycocalyx. The expression patterns of sub-glycans change in response to various biological events during disease pathogenesis; however, the structures of all major sub-glycans and their relative concentrations in a cell have been hardly reported. Total glycomic analysis, which comprehensively measures all major sub-glycans, is a powerful tool to discover cellular and clinical biomarkers.

Advances in total glycomic analysis including sialylated sub-glycan isomers by SALSA method.

All eukaryotic cell surfaces are coated with various types of glycans, which are essential molecules in biological events. In this review, we summarize recent integrated glycomics studies using various biological samples. We introduce an improved sialic acid linkage-specific alkylamidation (SALSA) method for sialylated glycan analysis and an automated glycosphingolipid-glycan preparation system for large-scale glycomic analysis of human plasma/serum.

Elevated A2F bisect N-glycans of serum IgA reflect progression of liver fibrosis in patients with MASLD.

Background: Advanced liver fibrosis in cases of metabolic dysfunction-associated steatotic liver disease (MASLD) leads to cirrhosis and hepatocellular carcinoma. The current gold standard for liver fibrosis is invasive liver biopsy. Therefore, a less invasive biomarker that accurately reflects the stage of liver fibrosis is highly desirable.

Associations between glycan signature alterations and the cellular antigenic properties of passaged chondrocytes.

Background: Cartilage repair is a significant clinical challenge because of the limited intrinsic healing capacity. Current therapeutic strategies, such as cell transplantation therapy, aim to overcome this challenge by replacing damaged tissue with healthy cells. However, the long-term survival and functionality of transplanted cells remain major hurdles.

The acetylglucosaminyltransferase GnT-Ⅲ regulates erythroid differentiation through ERK/MAPK signaling.

Differentiation therapy is an alternative strategy used in treating chronic myelogenous leukemia to induce the differentiation of immature or cancerous cells toward mature cells and inhibit tumor cell proliferation. We aimed to explore N-glycans' roles in erythroid differentiation using the sodium butyrate (NaBu)-induced model of K562 cells (WT/NaBu cells). Here, using lectin blot, flow cytometry, real-time PCR, and mass spectrometry analyses, we demonstrated that the mRNA levels of N-acetylglucosaminyltransferase Ⅲ ((encoded by the MGAT3 gene) and its product (bisected N-glycans) were significantly increased during erythroid differentiation.

Articular cartilage corefucosylation regulates tissue resilience in osteoarthritis.

This study aimed to investigate the glycan structural changes that occur before histological degeneration in osteoarthritis (OA) and to determine the mechanism by which these glycan conformational changes affect cartilage degeneration. An OA model was established in rabbits using mannosidase injection, which reduced high-mannose type N-glycans and led to cartilage degeneration. Further analysis of glycome in human OA cartilage identified specific corefucosylated N-glycan expression patterns.

Focal-adhesion kinase regulates the sialylation of N-glycans via the PI4KIIα-PI4P pathway.

Sialylation is a terminal glycosylated modification of glycoproteins that regulates critical biological events such as cell adhesion and immune response. Our previous study showed that integrin α3β1 plays a crucial role in regulating the sialylation of N-glycans. However, the underlying mechanism for the regulation remains unclear.

Simultaneous and sialic acid linkage-specific N- and O-linked glycan analysis by ester-to-amide derivatization.

Characterization of O-glycans linked to serine or threonine residues in glycoproteins has mostly been achieved using chemical reaction approaches because there are no known O-glycan-specific endoglycosidases. Most O-glycans are modified with sialic acid residues at the non-reducing termini through various linkages. In this study, we developed a novel approach for sialic acid linkage-specific O-linked glycan analysis through lactone-driven ester-to-amide derivatization combined with non-reductive β-elimination in the presence of hydroxylamine.

Exposure to brefeldin A induces unusual expression of hybrid- and complex-type free N-glycans in HepG2 cells.

This study determined the effect of brefeldin A (BFA) on the free N-glycomic profile of HepG2 cells to better understand the effect of blocking intracellular vesicle formation and transport of proteins from the endoplasmic reticulum to the Golgi apparatus. A series of exoglycosidase- and endoglycosidase-assisted analyses clarified the complex nature of altered glycomic profiles. A key feature of BFA-mediated alterations in Gn2-type glycans was the expression of unusual hybrid-, monoantennary- and complex-type free N-glycans (FNGs).

Comprehensive Glycan Analysis of Sphingolipids in Human Serum/Plasma.

Glycosphingolipids (GSLs) are glycolipids with ceramide and carbohydrate head groups that play an important role in numerous biological processes. Previously, we performed GSL-glycan analysis of various cell lines and virus-infected cells using a glycoblotting approach. Recently, we developed several methods for sialic acid linkage-specific chemical modification to distinguish sialylated glycan isomers by mass spectrometry.

Simultaneous determination of heparan sulfate, chondroitin/dermatan sulfates, and hyaluronan glycosaminoglycan disaccharides by high-performance liquid chromatography using a reverse-phase column with adamantyl groups.

Glycosaminoglycans (GAGs), which are one of the major components of proteoglycans, play a pivotal role in physiological processes such as signal transduction, cell adhesion, growth, and differentiation. Characterization of GAGs is challenging due to the tremendous structural diversity of heteropolysaccharides with numerous sulfate or carboxyl groups. In this present study, we examined the analysis of 2-aminobenzamide (2-AB) labeled GAG disaccharides by high-performance liquid chromatography (HPLC) using a reverse-phase (RP)-column with adamantyl groups.

Comprehensive Cellular Glycan Profiling of Glycoproteins and Glycosphingolipids by Glycoblotting and BEP Methods.

The glycocalyx is a layer of glycans that covers the surface of every cell. Glycans are covalently attached to proteins and lipids, and are classified into subclasses such as N-linked glycans, glycosaminoglycans, glycosphingolipid-glycans, free oligosaccharides, and O-linked glycans according to their biosynthetic pathways. These complex glycans affect various biological and pathological processes, such as cell growth, differentiation, and adhesion.

Establishment of the removal method of undifferentiated induced pluripotent stem cells coexisting with chondrocytes using R-17F antibody.

Tumorigenicity of residual undifferentiated induced pluripotent stem cells (iPSCs) is a major concern. The purpose of this study was to investigate the optimal conditions for removal of iPSCs using R-17F antibody, which recognizes specific glycosphingolipids glycans on undifferentiated iPSCs and exhibits selective cytotoxicity to iPSCs. After adding of R-17F and secondary antibody to co-cultured iPSCs and chondrocytes, residual iPSCs were quantitatively evaluated by iPS specific glycome analysis.

Evaluation of the context of downstream N- and free N-glycomic alterations induced by swainsonine in HepG2 cells.

Swainsonine (SWA), a potent inhibitor of class II α-mannosidases, is present in a number of plant species worldwide and causes severe toxicosis in livestock grazing these plants. The mechanisms underlying SWA-induced animal poisoning are not fully understood. In this study, we analyzed the alterations that occur in N- and free N-glycomic upon addition of SWA to HepG2 cells to understand better SWA-induced glycomic alterations.

Comprehensive and Comparative Structural Glycome Analysis in Mouse Epiblast-like Cells.

Glycosylation is one of the most abundant posttranslational modifications and is involved in a wide range of cellular processes. Glycome diversity in mammals is generated by the action of over 200 distinct glycosyltransferases and related enzymes. Nevertheless, glycosylation dynamics are tightly coordinated to allow proper organismal development.