O-GlcNAc glycosylation， as the most extensive type of glycosylation modification， is involved in the development and prognosis of ischemic stroke by regulating excitatory toxicity， mitochondrial function， synaptic plasticity， and immune metabolism and inhibiting endoplasmic reticulum stress and inflammatory response， and regulation of O-GlcNAc glycosylation is considered a promising therapeutic target for ischemic stroke.This article reviews the characteristics and specific mechanisms of O-GlcNAc glycosylation in ischemic stroke，in order to provide new ideas for the prevention and treatment of ischemic stroke.
Glycosylation

OBJECTIVE: This study prospectively investigates the association between immunoglobulin G (IgG) N-glycan traits and ischemic stroke (IS) risk. METHODS: A nested case-control study was conducted in the China suboptimal health cohort study, which recruited 4,313 individuals in 2013-2014. Cases were identified as patients diagnosed with IS, and controls were 1:1 matched by age and sex with cases. IgG N-glycans in baseline plasma samples were analyzed. RESULTS: A total of 99 IS cases and 99 controls were included, and 24 directly measured glycan peaks (GPs) were separated from IgG N-glycans. In directly measured GPs, GP4, GP9, GP21, GP22, GP23, and GP24 were associated with the risk of IS in men after adjusting for age, waist and hip circumference, obesity, diabetes, hypertension, and dyslipidemia. Derived glycan traits representing decreased galactosylation and sialylation were associated with IS in men (FBG2S2/(FBG2 + FBG2S1 + FBG2S2): odds ratio ( OR) = 0.92, 95% confidence interval ( CI): 0.87-0.97; G1 ⁿ: OR = 0.74, 95% CI: 0.63-0.87; G0 ⁿ: OR = 1.12, 95% CI: 1.03-1.22). However, these associations were not found among women. CONCLUSION This study validated that altered IgG N-glycan traits were associated with incident IS in men, suggesting that sex discrepancies might exist in these associations.
Male ; Humans ; Female ; Immunoglobulin G/metabolism* ; Ischemic Stroke ; Case-Control Studies ; Cohort Studies ; Glycosylation ; Polysaccharides

OBJECTIVE: To explore the clinical and molecular characteristics of a child with Congenital disorders of glycosylation (CDG). METHODS: A 4-month-old boy who had presented at the Children's Hospital Affiliated to Zhejiang University Medical School on December 31, 2019 due to feeding difficulties after birth was selected as the study subject. High-throughput sequencing was carried out for the patient, and real-time qPCR was used for validating the suspected deletion fragments and the carrier status of other members of his family. RESULTS: High-throughput sequencing revealed that the child had lost the capture signal for chrX: 153 045 645-153 095 809 (approximately 50 kb), which has involved 4 OMIM genes including SRPK3, IDH3G, SSR4 and PDZD4. qPCR verified that the copy number in this region was zero, while that of his elder brother and parents was all normal. CONCLUSION The deletion of the fragment containing the SSR4 gene in the Xq28 region probably underlay the SSR4-CDG in this child.
Aged ; Child ; Humans ; Infant ; Male ; Gene Deletion ; Glycosylation ; High-Throughput Nucleotide Sequencing ; Neoplasm Proteins ; Parents ; Siblings

Phosphomannomutase 2 deficiency is the most common form of N-glycosylation disorders and is also known as phosphomannomutase 2-congenital disorder of glycosylation (PMM2-CDG). It is an autosomal recessive disease with multi-system involvements and is caused by mutations in the PMM2 gene (OMIM: 601785), with varying severities in individuals. At present, there is still no specific therapy for PMM2-CDG, and early identification, early diagnosis, and early treatment can effectively prolong the life span of pediatric patients. This article reviews the advances in the diagnosis and treatment of PMM2-CDG.
Humans ; Child ; Congenital Disorders of Glycosylation/therapy* ; Mutation

The structure of N-glycans on specific proteins can regulate innate and adaptive immunity via sensing environmental signals. Meanwhile, the structural diversity of N-glycans poses analytical challenges that limit the exploration of specific glycosylation functions. In this work, we used THP-1-derived macrophages as examples to show the vast potential of a N-glycan structural interpretation tool StrucGP in N-glycoproteomic analysis. The intact glycopeptides of macrophages were enriched and analyzed using mass spectrometry (MS)-based glycoproteomic approaches, followed by the large-scale mapping of site-specific glycan structures via StrucGP. Results revealed that bisected GlcNAc, core fucosylated, and sialylated glycans (e.g., HexNAc₄Hex₅Fuc₁Neu5Ac₁, N₄H₅F₁S₁) were increased in M1 and M2 macrophages, especially in the latter. The findings indicated that these structures may be closely related to macrophage polarization. In addition, a high level of glycosylated PD-L1 was observed in M1 macrophages, and the LacNAc moiety was detected at Asn-192 and Asn-200 of PD-L1, and Asn-200 contained Lewis epitopes. The precision structural interpretation of site-specific glycans and subsequent intervention of target glycoproteins and related glycosyltransferases are of great value for the development of new diagnostic and therapeutic approaches for different diseases.
Humans ; B7-H1 Antigen ; Glycosylation ; Polysaccharides/metabolism*

OBJECTIVE: Xiaotan Sanjie recipe (XTSJ), a Chinese herbal compound medicine, exerts a significant inhibitory effect on gastric cancer (GC) metastasis. This work investigated the mechanism underlying the XTSJ-mediated inhibition of GC metastasis. METHODS: The effect of XTSJ on GC metastasis and the associated mechanism were investigated in vitro, using GC cell lines, and in vivo, using a GC mouse model, by focusing on the expression of Glc-N-Ac-transferase V (GnT-V; encoded by MGAT5). RESULTS: The migration and invasion ability of GC cells decreased significantly after XTSJ administration, which confirmed the efficacy of XTSJ in treating GC in vitro. XTSJ increased the accumulation of E-cadherin at junctions between GC cells, which was reversed by MGAT5 overexpression. XTSJ administration and MGAT5 knockdown alleviated the structural abnormality of the cell-cell junctions, while MGAT5 overexpression had the opposite effect. MGAT5 knockdown and XTSJ treatment also significantly increased the accumulation of proteins associated with the E-cadherin-mediated adherens junction complex. Furthermore, the expression of MGAT5 was significantly lower in the lungs of BGC-823-MGAT5 + XTSJ mice than in those of BGC-823-MGAT5 + solvent mice, indicating that the ability of gastric tumors to metastasize to the lung was decreased in vivo following XTSJ treatment. CONCLUSION XTSJ prevented GC metastasis by inhibiting the GnT-V-mediated E-cadherin glycosylation and promoting the E-cadherin accumulation at cell-cell junctions. Please cite this article as: Huang N, He HW, He YY, Gu W, Xu MJ, Liu L. Xiaotan Sanjie recipe, a compound Chinese herbal medicine, inhibits gastric cancer metastasis by regulating GnT-V-mediated E-cadherin glycosylation. J Integr Med. 2023; 21(6): 561-574.
Male ; Mice ; Animals ; Stomach Neoplasms/genetics* ; Drugs, Chinese Herbal/pharmacology* ; Glycosylation ; Cell Line, Tumor ; Cadherins/metabolism*

In carbohydrate chemistry, the stereoselective synthesis of 1,2-cis-glycosides remains a formidable challenge. This complexity is comparable to the synthesis of 1,2-cis-β-D-mannosides, primarily due to the adverse anomeric and Δ-2 effects. Over the past decades, to attain β-stereoselectivity in D-rhamnosylation, researchers have devised numerous direct and indirect methodologies, including the hydrogen-bond-mediated aglycone delivery (HAD) method, the synthesis of β-D-mannoside paired with C6 deoxygenation, and the combined approach of 1,2-trans-glycosylation and C2 epimerization. This review elaborates on the advancements in β-D-rhamnosylation and its implications for the total synthesis of tiacumicin B and other physiologically relevant glycans.
Glycosides ; Mannosides ; Glycosylation ; Stereoisomerism

COVID-19 represents the most serious public health event in the past few decades of the 21^st century. The development of vaccines, neutralizing antibodies, and small molecule chemical agents have effectively prevented the rapid spread of COVID-19. However, the continued emergence of SARS-CoV-2 variants have weakened the efficiency of these vaccines and antibodies, which brought new challenges for searching novel anti-SARS-CoV-2 drugs and methods. In the process of SARS-CoV-2 infection, the virus firstly attaches to heparan sulphate on the cell surface of respiratory tract, then specifically binds to hACE2. The S protein of SARS-CoV-2 is a highly glycosylated protein, and glycosylation is also important for the binding of hACE2 to S protein. Furthermore, the S protein is recognized by a series of lectin receptors in host cells. These finding implies that glycosylation plays important roles in the invasion and infection of SARS-CoV-2. Based on the glycosylation pattern and glycan recognition mechanisms of SARS-CoV-2, it is possible to develop glycan inhibitors against COVID-19. Recent studies have shown that sulfated polysaccharides originated from marine sources, heparin and some other glycans display anti-SARS-CoV-2 activity. This review summarized the function of glycosylation of SARS-CoV-2, discoveries of glycan inhibitors and the underpinning molecular mechanisms, which will provide guidelines to develop glycan-based new drugs against SARS-CoV-2.
Antibodies, Neutralizing ; Glycosylation ; Heparin ; Heparitin Sulfate ; Humans ; Polysaccharides/chemistry* ; Receptors, Mitogen/metabolism* ; SARS-CoV-2 ; Spike Glycoprotein, Coronavirus/metabolism* ; COVID-19 Drug Treatment

Immune-based therapies have experienced a pronounced breakthrough in the past decades as they acquired multiple US Food and Drug Administration (FDA) approvals for various indications. To date, six chimeric antigen receptor T cell (CAR-T) therapies have been permitted for the treatment of certain patients with relapsed/refractory hematologic malignancies. However, several clinical trials of solid tumor CAR-T therapies were prematurely terminated, or they reported life-threatening treatment-related damages to healthy tissues. The simultaneous expression of target antigens by healthy organs and tumor cells is partly responsible for such toxicities. Alongside targeting tumor-specific antigens, targeting the aberrantly glycosylated glycoforms of tumor-associated antigens can also minimize the off-tumor effects of CAR-T therapies. Tn, T, and sialyl-Tn antigens have been reported to be involved in tumor progression and metastasis, and their expression results from the dysregulation of a series of glycosyltransferases and the endoplasmic reticulum protein chaperone, Cosmc. Moreover, these glycoforms have been associated with various types of cancers, including prostate, breast, colon, gastric, and lung cancers. Here, we discuss how underglycosylated antigens emerge and then detail the latest advances in the development of CAR-T-based immunotherapies that target some of such antigens.
Antigens, Neoplasm/chemistry* ; Biomarkers, Tumor/metabolism* ; Glycosylation ; Hematologic Neoplasms/drug therapy* ; Humans ; Immunotherapy, Adoptive/methods* ; Male ; Neoplasm Recurrence, Local/metabolism* ; Receptors, Chimeric Antigen ; T-Lymphocytes ; United States

Genistein and its monoglucoside derivatives play important roles in food and pharmaceuticals fields, whereas their applications are limited by the low water solubility. Glycosylation is regarded as one of the effective approaches to improve water solubility. In this paper, the glycosylation of sophoricoside (genistein monoglucoside) was investigated using a cyclodextrin glucosyltransferase from Penibacillus macerans (PmCGTase). Saturation mutagenesis of D182 from PmCGTase was carried out. Compared with the wild-type (WT), the variant D182C showed a 13.42% higher conversion ratio. Moreover, the main products sophoricoside monoglucoside, sophoricoside diglucoside, and sophoricoside triglucoside of the variant D182C increased by 39.35%, 56.05% and 64.81% compared with that of the WT, respectively. Enzymatic characterization showed that the enzyme activities (cyclization, hydrolysis, disproportionation) of the variant D182C were higher than that of the WT, and the optimal pH and temperature of the variant D182C were 6 and 40℃, respectively. Kinetics analysis showed the variant D182C has a lower K_m value and a higher k_cat/K_m value than that of the WT, indicating the variant D182C has enhanced affinity to substrate. Structure modeling and docking analysis demonstrated that the improved glycosylation efficiency of the variant D182C may be attributed to the increased interactions between residues and substrate.
Cyclodextrins ; Genistein ; Glucosyltransferases/metabolism* ; Glycosylation ; Kinetics