Artificial and Natural Sialic Acid Precursors Influence the Angiogenic Capacity of Human Umbilical Vein Endothelial Cells

Autor: Sebastian P. Galuska, Klaus T. Preissner, Hildegard Geyer, Rudolf Geyer, Heike Hausmann, Sandra Frank, Silvia Rudloff, Uwe Schubert, Zehra Sentürk, Nils B. Bayer
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Zdroj: Molecules, Vol 18, Iss 3, Pp 2571-2586 (2013)
Druh dokumentu: article
ISSN: 1420-3049
DOI: 10.3390/molecules18032571
Popis: N-acetylneuraminic acid (Neu5Ac) represents the most common terminal carbohydrate residue in many mammalian glycoconjugates and is directly involved in a number of different physiological as well as pathological cellular processes. Endogenous sialic acids derive from the biosynthetic precursor molecule N-acetyl-D-mannosamine (ManNAc). Interestingly, N-acyl-analogues of D-mannosamine (ManN) can also be incorporated and converted into corresponding artificial sialic acids by eukaryotic cells. Within this study, we optimized a protocol for the chemical synthesis of various peracetylated ManN derivatives resulting in yields of approximately 100%. Correct molecular structures of the obtained products ManNAc, N-propanoyl-ManN (ManNProp) and N-butyl-ManN (ManNBut) were verified by GC-, ESI-MS- and NMR-analyses. By applying these substances to human umbilical vein endothelial cells (HUVECs), we could show that each derivative was metabolized to the corresponding N-acylneuraminic acid variant and subsequently incorporated into nascent glycoproteins. To investigate whether natural and/or artificial sialic acid precursors are able to modulate the angiogenic capacity of HUVECs, a spheroid assay was performed. By this means, an increase in total capillary length has been observed when cells incorporated N-butylneuraminic acid (Neu5But) into their glycoconjugates. In contrast, the natural precursor ManNAc inhibited the growth of capillaries. Thus, sialic acid precursors may represent useful agents to modulate blood vessel formation.
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