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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.
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Humans , B7-H1 Antigen , Glycosylation , Polysaccharides/metabolismABSTRACT
Objective To investigate the expression of multi-glycan in serum of patients with dual-phenotype hepatocellular (DPHCC) and its clinical significance. Methods Serum samples were collected from 65 patients with DPHCC, 80 patients with primary hepatocellular carcinoma (HCC), and 120 patients with liver cirrhosis (LC) who were treated in Mengchao Hepatobiliary Hospital of Fujian Medical University from June 2019 to December 2020. DNA sequencer-aided fluorophore-assisted carbohydrate electrophoresis was used to measure the expression of N-glycan in serum, The measurement data of normal distribution were compared by t -test between the two groups and analysis of variance between multiple groups; The measurement data with non normal distribution were compared by Mann-Whitney U test between the two groups and Kruskal-Wallis H test between multiple groups, the chi-square test was used for comparison of categorical data between groups.The logistic regression method was used to establish the common index model. The efficacy of AFP, PIVKA - Ⅱ, CEA, CA19-9 and multi glycan in the diagnosis of DPHCC was evaluated by receiver operating characteristic (ROC) curve, and the area under ROC curve (AUC) was compared by Z test. Results There was a significant difference in multi-glycan between the DPHCC group and the HCC group ( P < 0.001), while there were no significant differences in AFP, PIVKA-Ⅱ, CEA, CA19-9, and SUM between the two groups ( P =0.924, 0.084, 0.442, 0.924, and 0.206). Multi-glycan had an area under the ROC curve (AUC) of 0.775, which was significantly higher than that of AFP (0.507), PIVKA-Ⅱ (0.584), CEA (0.537), CA19-9 (0.505), and SUM (0.561), and multi-glycan had a sensitivity of 69.23%, which was increased compared with the other 5 items. There were significant differences in multi-glycan, AFP, PIVKA-Ⅱ, CA19-9, and SUM between the DPHCC group and the LC group (all P < 0.001), but there was no significant difference in CEA between the two groups ( P =0.14). Multi-glycan had an AUC of 0.780, which was also higher than that of AFP (0.767), PIVKA-Ⅱ (0.743), CEA (0.566), CA19-9 (0.689), and SUM (0.713), and multi-glycan had a sensitivity of 89.23%, which was increased compared with the other five items. Conclusion Multi-glycan can be used as one of the indicators for the auxiliary diagnosis of DPHCC.
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In recent years, the biopharmaceutical industry has grown rapidly, and the market size of monoclonal antibody drugs has increased significantly. Accurate structural characterization and quality control are the supporting technologies for the development of monoclonal antibody drugs. As a significant post-translational modification of antibody drugs, glycosylation has an important influence on its efficacy, stability, and immunogenicity. The existing literature usually uses liquid chromatography-mass spectrometry to perform major glycosylation modifications of monoclonal antibody drugs. Characterization, there are few studies on low-abundance glycosylation, but the characterization and control of low-abundance glycosylation cannot be ignored. In this study, we have established a qualitative and quantitative analysis technology for N-glycans based on RapiFluor-MS reagent-labeled monoclonal antibody drugs. This method has a short sample processing time and high sensitivity. It can not only characterize the main glycoforms of three monoclonal antibody drugs (adalimumab, bevacizumab, and trastuzumab) but also can quantify low-abundance N-glycans. The results of the study showed that the main glycoforms specified in the Pharmacopoeia could be detected in different batches of monoclonal antibody drugs, but the content of N-glycans in different batches of samples is not identical. After that, we analyzed the N-glycans connection sites and glycoforms at the intact glycopeptide level, further enriching the N-glycans structure information of the monoclonal antibody. The qualitative and quantitative analysis technology of N-glycans based on RapiFluor-MS reagent-labeled monoclonal antibody drugs can realize the in-depth characterization and control of glycosylation modification of monoclonal antibody drugs.
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ObjectiveTo investigate the potential mechanism of serum N-glycan alterations in patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) by measuring serum N-glycan profile and comparing glycosyltransferase gene expression between HCC tissue and adjacent tissue. MethodsThe samples of HCC tissue, adjacent tissue, and normal liver tissue were collected from 34 patients with HBV-related HCC who were admitted to Chinese PLA General Hospital, and serum samples were also collected. Among these 34 patients, 8 were randomly selected and their serum samples were established as HCC experimental group, and the serum samples of 20 healthy adults were established as control group. DNA sequencer-aided fluorophore-assisted carbohydrate electrophoresis was used to analyze serum N-glycan profile in the HCC experimental group and the control group. Quantitative real-time PCR was used to measure the mRNA expression of 8 glycosyltransferase genes (FUT3, FUT4, FUT6, FUT7, FUT8, Gn-TIII, Gn-TIVa, and Gn-TV) in the HCC tissue and adjacent tissue of 34 patients with HBV-related HCC, and Western blot was used to measure the expression of corresponding proteins. The independent samples t-test was used for comparison of continuous data between two groups. ResultsCompared with the control group, the HCC experimental group had a significant increase in the abundance of N-glycan peak9 (NA3Fb) in serum(t=-2.514,P＜0.05). There were significant differences in the mRNA expression of FUT8, Gn-TIVa, and Gn-TV between HCC tissue and adjacent tissue, and the mRNA and protein expression levels of FUT8 and Gn-TV in HCC tissue were significantly higher than those in adjacent tissue (FUT8 mRNA: 1.50±0.34 vs 0.65±0.11, t=-2.354，P=0.022; Gn-TV mRNA: 3.57±0.64 vs 1.33±016, t=-3.384,P=0001; FUT8 protein: 0.70±0.11 vs 0.083±0.017, t=9.555,P=0.001; Gn-TV protein: 1.33±0.19 vs 0.60±0.15, t=5.097,P=0.007). The mRNA expression level of Gn-TIVa in HCC tissue was significantly higher than that in adjacent tissue (2.90±0.47 vs 1.68±0.19, t=-2.403,P=0.019), but there was no significant difference in the protein expression level of Gn-TIVa between HCC tissue and adjacent tissue (052±0.24 vs 0.24±0.11,t=1.833, P=0.141). The changes of glycosyltransferase gene expression in HCC tissue were consistent with the alteration of serum N-glycan profile. ConclusionSerum N-glycan alterations in patients with HBV-related HCC may be closely associated with the upregulated expression of the glycosyltransferase genes FUT8, Gn-TIVa, and Gn-TV in HCC tissue.
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The glycosylation of proteins is responsible for their structural and functional roles in many cellular activities. This work describes a strategy that combines an efficient release, labeling and liquid chromatography–mass spectral analysis with the use of a comprehensive database to analyze N-glycans. The analytical method described relies on a recently commercialized kit in which quick deglycosylation is followed by rapid labeling and cleanup of labeled glycans. This greatly improves the separation, mass spectrometry (MS) analysis and fluorescence detection of N-glycans. A hypothetical database, constructed using GlycResoft, provides all compositional possibilities of N-glycans based on the common sugar residues found in N-glycans. In the initial version this database contains >8,700 N-glycans, and is compatible with MS instrument software and expandable. N-glycans from four different well-studied glycoproteins were analyzed by this strategy. The results provided much more accurate and comprehensive data than that had been previously reported. This strategy was then used to analyze the N-glycans present on the membrane glycoproteins of gastric carcinoma cells with different degrees of differentiation. Accurate and comprehensive N-glycan data from those cells was obtained efficiently and their differences were compared corresponding to their differentiation states. Thus, the novel strategy developed greatly improves accuracy, efficiency and comprehensiveness of N-glycan analysis.
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Objective Detecting the influence of swainsonine bring in the expression of N?glycan of osteosarcoma tumor stem cells. Methods LM8 cells were cultured in the culture medium (free of serum), then selected the LM8 cells of both CD44 and CD133 positive by magnetic activated cell sorting technique. Detecting the levels ofβ1, 6 branch N?glycan expression in the selected LM8 cells (treating by different doses of N?glycosylation inhibitor swainsonine) surface through the lectin binding assay (L?PHA). Results (96.5 ± 1.2)%of LM8 cells were both CD133 and CD44 positive which selected from all the LM8 cells in culture medium (free of serum) by magnetic activated cell sorting technique. Lectin binding assays shown that the bound rare of osteosarcoma tumor stem cells and L?PHA was (90.3 ± 2.1)%, which was higher than normal LM8 cells and L?PHA by (54.3 ± 3.1)%(P<0.05). The positive rare ofβ1, 6 branch N?glycan on the selected LM8 cells(treat with 1mg/mL swainsonine) surface was 90%. The positive rare of β1, 6 branch N?glycan on the selected LM8 cells (treat with 5mg/mL swainsonine) surface was 21%. Conclusion N?glycosylation inhibitor swainsonine plays a role in inhibiting the expression of N?glycan on cell surface of osteosarcoma tumor stem cell.
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ObjectiveTo discuss the changes in characteristics of N-glycan in gastric cancer and its relationship with TCM syndromes.Methods The blood samples of 138 gastric cancer patients and 120 healthy volunteers were collected. The changes in N-glycan were detected by DNA sequencer-assisted and fluorophore-assisted carbohydrate electrophoresis (DSA-FACE), and differences of N-glycan among different TCM syndromes were compared.Results At least 9 N-glycan peaks could be identified in all samples. Compared with the healthy volunteers, Peak1, Peak5, Peak9 and Peak2 of gastric cancer patients obviously increased (P<0.05,P<0.01), whereas Peak3, Peak6 significantly decreased (P<0.01). Peak6 of gastric cancer in stage I was obviously higher than stages II, III, and IV (P<0.01), while Peak9 in stage I was obviously lower than the other three stages (P<0.01). Peak1 was significantly lower in disharmony between liver and stomach type than stagnation of phlegm-dampness type, interior retention of toxin stagnation type, deficiency of both Qi and blood type (P<0.05,P<0.01);lower in impairment of yin due to stomach heat type, deficiency-cold in spleen and stomach type than deficiency of both Qi and blood type (P<0.01);lower in stagnation of phlegm-dampness type, interior retention of toxin stagnation type than deficiency of both Qi and blood type (P<0.05). Peak6 was higher in disharmony between liver and stomach type than impairment of yin due to stomach heat type, stagnation of phlegm-dampness type, interior retention of toxin stagnation type than deficiency of both Qi and blood type (P<0.01). Peak9 was much higher in deficiency of both Qi and blood type than disharmony between liver and stomach type (P<0.01), impairment of yin due to stomach heat type and deficiency-cold in spleen and stomach type (P<0.05, P<0.01).Conclusion The expression of N-glycan was specifically changed in gastric cancer. These variations could promote the metastasis of gastric cancer and potentially have certain correlation with TCM syndromes.
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Human malignant malaria is caused by Plasmodium falciparum and accounts for almost 900,000 deaths per year, the majority of which are children and pregnant women in developing countries. There has been significant effort to understand the biology of P. falciparum and its interactions with the host. However, these studies are hindered because several aspects of parasite biology remain controversial, such as N- and O-glycosylation. This review describes work that has been done to elucidate protein glycosylation in P. falciparum and it focuses on describing biochemical evidence for N- and O-glycosylation. Although there has been significant work in this field, these aspects of parasite biochemistry need to be explored further.