Control of lupus activity during pregnancy via the engagement of IgG sialylation: novel crosstalk between IgG sialylation and pDC functions / 医学前沿

Immunoglobulin (IgG) glycosylation affects the effector functions of IgG in a myriad of biological processes and has been closely associated with numerous autoimmune diseases, including systemic lupus erythematosus (SLE), thus underlining the pathogenic role of glycosylation aberration in autoimmunity. This study aims to explore the relationship between IgG sialylation patterns and lupus pregnancy. Relative to that in serum samples from the control cohort, IgG sialylation level was aberrantly downregulated in serum samples from the SLE cohort at four stages (from preconception to the third trimester of pregnancy) and was significantly associated with lupus activity and fetal loss during lupus pregnancy. The type I interferon signature of pregnant patients with SLE was negatively correlated with the level of IgG sialylation. The lack of sialylation dampened the ability of IgG to suppress the functions of plasmacytoid dendritic cells (pDCs). RNA-seq analysis further revealed that the expression of genes associated with the spleen tyrosine kinase (SYK) signaling pathway significantly differed between IgG- and deSia-IgG-treated pDCs. This finding was confirmed by the attenuation of the ability to phosphorylate SYK and BLNK in deSia-IgG. Finally, the coculture of pDCs isolated from pregnant patients with SLE with IgG/deSia-IgG demonstrated the sialylation-dependent anti-inflammatory function of IgG. Our findings suggested that IgG influences lupus activity through regulating pDCs function via the modulation of the SYK pathway in a sialic acid-dependent manner.

Progress in technology for glycomics / 中国药理学与毒理学杂志

Technologies for glycomics usually involve methods for separation and purification of poly-saccharides, and separation, structure resolution, quantification, property investigation and function comment of glycan chains. Because of the different biochemical properties of glycoproteins, proteogly-cans and glycolipids, the separation and purification of polysaccharides involve corresponding fractional precipitation, boric acid affinity, titanium dioxide, affinity chromatography, size exclusion method, and gel filtration chromatography column chromatography methods. The lectins, water affinity chromatogra-phy , solid phase extraction and other technologies could be applied to the oil enrichment of high pure and specific glycan chains. The structure of glycan chains can be analyzed using lectin microarray technolo-gy, mass spectrometry, and derivatization markers of glycan chains. lsotope labelling and metabolic labeling can be used to quantify glycan chains. The glycan biological function can be better understood using glycan chain structure analysis software and database of glycan chains by bioinformatics.

Expression of N-glycome in sera of patients with hepatocellular carcinoma / 第二军医大学学报

Objective: To compare the expression profiles of serum glycomics between hepatocellular carcinoma(HCC) patients and normal adults, in an attempt to search for new biomarkers for HCC. Methods: Serum samples were obtained from HCC patients with hepatitis B virus(HBV) infection (n = 100) and normal adults(n = 130). Profiles of serum N-glycome were determined by capillary electrophoresis (CE) based on DNA sequencing equipment. Results: Each sample had a profile with 11 peaks; the peaks were adjusted and quantified. Peaks 1, 2, 9, and 11 in HCC group were higher than those in the control group; peaks 6, 8 and 10 were lower in HCC group than those in control group (P<0.05). The changes of peak values of several peaks were correlated with tumor markers such as alpha-fetoprotein(AFP), HBV DNA copies, albumin and prothrombin time. Conclusion: N-glycome profiles in serum are significantly different between HCC patients and normal adults, which may provide evidence for clinical diagnosis of HCC.