The NEU1-selective sialidase inhibitor, C9- butyl-amide-DANA, blocks sialidase activity and NEU1-mediated bioactivities in human lung in vitro and murine lung in vivo

Authors

• Sang W. Hyun, Baltimore Veterans Affairs Medical Center
• Anguo Liu, Baltimore Veterans Affairs Medical Center
• Zhenguo Liu, Baltimore Veterans Affairs Medical Center
• Alan S. Cross, University of Maryland School of Medicine
• Avelino C. Verceles, University of Maryland School of Medicine
• Sadagopan Magesh, Gifu University
• Yadagiri Kommagalla, Gifu University
• Chandrababunaidu Kona, Gifu University
• Hiromune Ando, Gifu University
• Irina G. Luzina, Baltimore Veterans Medical Center
• Sergei P. Atamas, Baltimore Veterans Affairs Medical Center
• Kurt H. Piepenbrink, University of Maryland School of MedicineFollow
• Eric J. Sundberg, University of Maryland School of Medicine
• Wei Guang, University of Maryland School of Medicine
• Hideharu Ishida, Gifu University
• Erik P. Lillehoj, University of Maryland School of Medicine
• Simeon E. Goldblum, Baltimore Veterans Affairs Medical Center

Date of this Version

9-2-2016

Document Type

Article

Citation

Glycobiology. 2016 Aug; 26(8): 834–849. Published online 2016 Sep 2. doi: 10.1093/glycob/cww060 PMCID: PMC5884327 PMID: 27226251

Abstract

Neuraminidase-1 (NEU1) is the predominant sialidase expressed in human airway epithelia and lung microvascular endothelia where it mediates multiple biological processes. We tested whether the NEU1-selective sialidase inhibitor, C9-butyl-amide-2-deoxy-2,3-dehydro-Nacetylneuraminic acid (C9-BA-DANA), inhibits one or more established NEU1-mediated bioactivities in human lung cells. We established the IC50 values of C9-BA-DANA for total sialidase activity in human airway epithelia, lung microvascular endothelia and lung fibroblasts to be 3.74 µM, 13.0 µM and 4.82 µM, respectively. In human airway epithelia, C9-BA-DANA dose-dependently inhibited flagellin-induced, NEU1-mediated mucin-1 ectodomain desialylation, adhesiveness for Pseudomonas aeruginosa and shedding. In lung microvascular endothelia, C9-BA-DANA reversed NEU1-driven restraint of cell migration into a wound and disruption of capillary-like tube formation. NEU1 and its chaperone/transport protein, protective protein/cathepsin A (PPCA), were differentially expressed in these same cells. Normalized NEU1 protein expression correlated with total sialidase activity whereas PPCA expression did not. In contrast to eukaryotic sialidases, C9-BA-DANA exerted far less inhibitory activity for three selected bacterial neuraminidases (IC₅₀ > 800 µM). Structural modeling of the four human sialidases and three bacterial neuraminidases revealed a loop between the seventh and eighth strands of the β-propeller fold, that in NEU1, was substantially shorter than that seen in the six other enzymes. Predicted steric hindrance between this loop and C9-BA-DANA could explain its selectivity for NEU1. Finally, pretreatment of mice with C9-BA-DANA completely protected against flagellin-induced increases in lung sialidase activity. Our combined data indicate that C9- BA-DANA inhibits endogenous and ectopically expressed sialidase activity and established NEU1-mediated bioactivities in human airway epithelia, lung microvascular endothelia, and fibroblasts in vitro and murine lungs in vivo.