title: Sialylation and desialylation dynamics of monocytes upon differentiation and polarization to macrophages.
abstract: Sialic acids (SAs) often exist as the terminal sugars of glycan structures of cell surface glycoproteins and glycolipids. The level and linkages of cell surface SAs, which are controlled by both sialylation and desialylation processes and environment cues, can dramatically impact cell properties and represent different cellular status. In this study, we systematically examined the sialylation and desialylation profiles of THP-1 monocytes after differentiation to M0 macrophages, and polarization to M1 and M2 macrophages by the combination of LC-MS/MS, flow cytometry and confocal microscopy. Interestingly, both α2-3- and α2-6-linked SAs on the cell surface decreased after monocytes were differentiated to macrophages, which was in accordance with the increased level of free SA in the cell culture medium and the elevated activity of endogenous Neu1 sialidase. Meanwhile, the siaoglycoconjugates inside the cells increased as confirmed by confocal microscopy and the total SA inside the cells increased as determined by LC-MS/MS. Western blot analysis showed higher expression levels of sialyltransferases, including ST3Gal-I, ST3Gal-V, ST6Gal-I and ST6GalNAc-II. Further, upon polarization, the cell surface sialylation levels of M1 and M2 macrophages remained the same as M0 macrophages, while a slight decrease of cellular SAs in the M1 macrophages but increase in the M2 macrophages were confirmed by LC-MS/MS.
authors.affiliation: Department of Chemistry, Chemical and Biomedical Engineering and Center for Gene Regulation in Health and Disease (GRHD), Cleveland State University, 2121 Euclid Avenue, Cleveland, OH, 44115, USA.
authors.forename: Dan
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Chemical and Biomedical Engineering and Center for Gene Regulation in Health and Disease (GRHD), Cleveland State University, 2121 Euclid Avenue, Cleveland, OH, 44115, USA.
authors.forename: Evgeny
authors.initials: E
authors.lastname: Ozhegov
authors.affiliation: Department of Chemistry, Chemical and Biomedical Engineering and Center for Gene Regulation in Health and Disease (GRHD), Cleveland State University, 2121 Euclid Avenue, Cleveland, OH, 44115, USA.
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Chemical and Biomedical Engineering and Center for Gene Regulation in Health and Disease (GRHD), Cleveland State University, 2121 Euclid Avenue, Cleveland, OH, 44115, USA.
authors.forename: Aimin
authors.initials: A
authors.lastname: Zhou
authors.affiliation: School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, 150000, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Nie
authors.affiliation: School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, 150000, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Chemistry, Chemical and Biomedical Engineering and Center for Gene Regulation in Health and Disease (GRHD), Cleveland State University, 2121 Euclid Avenue, Cleveland, OH, 44115, USA. x.sun55@csuohio.edu.
authors.forename: Xue-Long
authors.initials: XL
authors.lastname: Sun
mesh_terms: D002454:Cell Differentiation / Q000502:physiology*; D045744:Cell Line, Tumor; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D006017:Glycolipids / Q000378:metabolism*; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D008264:Macrophages / Q000166:cytology / Q000378:metabolism*; D009000:Monocytes / Q000166:cytology / Q000378:metabolism*; D019158:N-Acetylneuraminic Acid / Q000378:metabolism*; D009439:Neuraminidase / Q000096:biosynthesis; D012799:Sialyltransferases / Q000096:biosynthesis
chemical_list: D006017:Glycolipids; D006023:Glycoproteins; D012799:Sialyltransferases; C486385:NEU1 protein, human; D009439:Neuraminidase; D019158:N-Acetylneuraminic Acid
keywords: Desialylation; Differentiation, polarization; Macrophage; Monocyte; Sialic acid; Sialylation