title: Chemically modified N-acylated hyaluronan fragments modulate proinflammatory cytokine production by stimulated human macrophages.
abstract: Low molecular mass hyaluronans are known to induce inflammation. To determine the role of the acetyl groups of low molecular mass hyaluronan in stimulating the production of proinflammatory cytokines, partial N-deacetylation was carried out by hydrazinolysis. This resulted in 19.7 ± 3.5% free NH2 functional groups, which were then acylated by reacting with an acyl anhydride, including acetic anhydride. Hydrazinolysis resulted in bond cleavage of the hyaluronan chain causing a reduction of the molecular mass to 30-214 kDa. The total NH2 and N-acetyl moieties in the reacetylated hyaluronan were 0% and 98.7 ± 1.5% respectively, whereas for butyrylated hyaluronan, the total NH2, N-acetyl, and N-butyryl moieties were 0, 82.2 ± 4.6, and 22.7 ± 3.8%, respectively, based on (1)H NMR. We studied the effect of these polymers on cytokine production by cultured human macrophages (THP-1 cells). The reacetylated hyaluronan stimulated proinflammatory cytokine production to levels similar to LPS, whereas partially deacetylated hyaluronan had no stimulatory effect, indicating the critical role of the N-acetyl groups in the stimulation of proinflammatory cytokine production. Butyrylated hyaluronan significantly reduced the stimulatory effect on cytokine production by the reacetylated hyaluronan or LPS but had no stimulatory effect of its own. The other partially N-acylated hyaluronan derivatives tested showed smaller stimulatory effects than reacetylated hyaluronan. Antibody and antagonist experiments suggest that the acetylated and partially butyrylated lower molecular mass hyaluronans exert their effects through the TLR-4 receptor system. Selectively N-butyrylated lower molecular mass hyaluronan shows promise as an example of a novel semisynthetic anti-inflammatory molecule.
authors: From the Department of Medicine, Division of Rheumatology and.
authors: Oladunni
authors: O
authors: Babasola
authors: From the Department of Medicine, Division of Rheumatology and.
authors: Karen J
authors: KJ
authors: Rees-Milton
authors: From the Department of Medicine, Division of Rheumatology and.
authors: Siziwe
authors: S
authors: Bebe
authors: the Department of Chemistry, Queen's University, Kingston, Ontario K7L 3N6, Canada.
authors: Jiaxi
authors: J
authors: Wang
authors: From the Department of Medicine, Division of Rheumatology and anastass@queensu.ca.
authors: Tassos P
authors: TP
authors: Anastassiades
mesh_terms: D000215:Acylation; D002087:Butyrates / Q000378:metabolism; D002240:Carbohydrate Sequence; D045744:Cell Line, Tumor; D016207:Cytokines / Q000378:metabolism*; D006801:Humans; D006820:Hyaluronic Acid / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D006834:Hydrazines / Q000378:metabolism; D018836:Inflammation Mediators / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D015394:Molecular Structure; D008970:Molecular Weight; D013997:Time Factors; D051197:Toll-Like Receptor 4 / Q000378:metabolism
chemical_list: D002087:Butyrates; D016207:Cytokines; D006834:Hydrazines; D018836:Inflammation Mediators; D008070:Lipopolysaccharides; D051197:Toll-Like Receptor 4; C029424:hydrazine; D006820:Hyaluronic Acid
keywords: CD44; Cytokine; Glycobiology; Hyaluronan; Hyaluronate; Inflammation; Macrophage; N-Acylation; Polymers; Toll-like Receptor (TLR)