Globally profiling sialylation status of macrophages upon statin treatment

Abstract

Sialic acids (SAs) are widely expressed on immune cells and their levels and linkages named as sialylation status vary upon cellular environment changes related to both physiological and pathological processes. In this study, we performed a global profiling of the sialylation status of macrophages and their release of SAs in the cell culture medium by using flow cytometry, confocal microscopy and liquid chromatography tandem mass spectrometry (LC-MS/MS). Both flow cytometry and confocal microscopy results showed that cell surface α-2,3-linked SAs were predominant in the normal culture condition and changed slightly upon treatment with atorvastatin for 24 h, whereas α-2,6-linked SAs were negligible in the normal culture condition but significantly increased after treatment. Meanwhile, the amount of total cellular SAs increased about three times (from 369 ± 29 to 1080 ± 50 ng/mL) upon treatment as determined by the LC-MS/MS method. On the other hand, there was no significant change for secreted free SAs and conjugated SAs in the medium. These results indicated that the cell surface α-2,6 sialylation status of macrophages changes distinctly upon atorvastatin stimulation, which may reflect on the biological functions of the cells.

Biological Functions and Analytical Strategies of Sialic Acids in Tumor

“…Lectins are sugar-binding proteins that can specifically recognize glycans on glycoconjugates. Sambucus nigra lectin (SNA) and Maackia amurensis lectin (MAL) are commonly used to Cells 2020, 9, 273 7 of 18 recognize the α2,6-linked and α2,3-linked sialic acid residues, respectively [116][117][118], in lectin blot [119], lectin microarray [120][121][122], histochemistry [123], fluorescent image and flow cytometry [56,124]. Using lectin MAL-1, α2,3-linked sialic acids were found to promote gastric cancer cell metastasis [125].…”

The Structure of Leukocyte Sialic Acid-Containing Membrane Glycoconjugates is a Differential Indicator of the Development of Diabetic Complications

“…The Maackia amurensis lectin (MAA) and Sambucus nigra lectin (SNA) are commonly used to recognize the α2,3-linked (Neu5Acα2,3Gal) and α2,6-linked (Neu5Acα2,6Gal/GalNAc) sialic acid residues, respectively [20,68,69]. Sialospecific lectins apply in lectin microarray [70], histochemistry [71], in lectin blot [72,73], fluorescent image and flow cytometry [74] (Figure 1). At the same time, the combination of lectins with monoclonal antibodies can be used to obtain complete information on the antigenic repertoire of cells both in normal and in case of pathologies [73].…”

Fundamentals of Glycosylation

“…RAGE is a single-pass 45-kDa transmembrane protein belonging to the immunoglobulin superfamily and was first isolated and identified from bovine lungs as a cell surface receptor that binds to AGEs [74]. RAGE is expressed in monocytes, macrophages, nerves, renal tubule cells, and mesangial cells [75].…”