title: Glycan imaging in intact rat hearts and glycoproteomic analysis reveal the upregulation of sialylation during cardiac hypertrophy.
abstract: In the heart, glycosylation is involved in a variety of physiological and pathological processes. Cardiac glycosylation is dynamically regulated, which remains challenging to monitor in vivo. Here we describe a chemical approach for analyzing the dynamic cardiac glycome by metabolically labeling the cardiac glycans with azidosugars in living rats. The azides, serving as a chemical reporter, are chemoselectively conjugated with fluorophores using copper-free click chemistry for glycan imaging; derivatizing azides with affinity tags allows enrichment and proteomic identification of glycosylated cardiac proteins. We demonstrated this methodology by visualization of the cardiac sialylated glycans in intact hearts and identification of more than 200 cardiac proteins modified with sialic acids. We further applied this methodology to investigate the sialylation in hypertrophic hearts. The imaging results revealed an increase of sialic acid biosynthesis upon the induction of cardiac hypertrophy. Quantitative proteomic analysis identified multiple sialylated proteins including neural cell adhesion molecule 1, T-kininogens, and α2-macroglobulin that were upregulated during hypertrophy. The methodology may be further extended to other types of glycosylation, as exemplified by the mucin-type O-linked glycosylation. Our results highlight the applications of metabolic glycan labeling coupled with bioorthogonal chemistry in probing the biosynthesis and function of cardiac glycome during pathophysiological responses.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, ‡State Key Laboratory of Biomembrane and Membrane Biotechnology, College of Life Sciences, §Synthetic and Functional Biomolecules Center, and ∥Peking-Tsinghua Center for Life Sciences, Peking University , Beijing 100871, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Rong
authors.forename: Jing
authors.initials: J
authors.lastname: Han
authors.forename: Lu
authors.initials: L
authors.lastname: Dong
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Tan
authors.forename: Huaqian
authors.initials: H
authors.lastname: Yang
authors.forename: Lianshun
authors.initials: L
authors.lastname: Feng
authors.forename: Qi-Wei
authors.initials: QW
authors.lastname: Wang
authors.forename: Rong
authors.initials: R
authors.lastname: Meng
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.forename: Shi-Qiang
authors.initials: SQ
authors.lastname: Wang
authors.forename: Xing
authors.initials: X
authors.lastname: Chen
mesh_terms: D000818:Animals; D057791:Cardiac Imaging Techniques; D006332:Cardiomegaly / Q000503:physiopathology*; D018618:Echocardiography, Doppler, Color; D008562:Membrane Glycoproteins / Q000737:chemistry; D008856:Microscopy, Fluorescence; D032383:Myocytes, Cardiac / Q000737:chemistry*; D019158:N-Acetylneuraminic Acid / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry; D040901:Proteomics; D051381:Rats; D012795:Sialoglycoproteins / Q000737:chemistry; D015854:Up-Regulation
chemical_list: D008562:Membrane Glycoproteins; D011134:Polysaccharides; D012795:Sialoglycoproteins; D019158:N-Acetylneuraminic Acid