Sialic acids are important components of glycoproteins and glycolipids essential for cellular communication, infection, and metastasis. The importance of sialic acid biosynthesis in human physiology is well illustrated by the severe metabolic disorders in this pathway. However, the biological role of sialic acid catabolism in humans remains unclear. Here, we present evidence that sialic acid catabolism is important for heart and skeletal muscle function and development in humans and zebrafish. In two siblings, presenting with sialuria, exercise intolerance/muscle wasting, and cardiac symptoms in the brother, compound heterozygous mutations [chr1:182775324C>T (c.187C>T; p.Arg63Cys) and chr1:182772897A>G (c.133A>G; p.Asn45Asp)] were found in the N-acetylneuraminate pyruvate lyase gene (NPL). In vitro, NPL activity and sialic acid catabolism were affected, with a cell-type-specific reduction of N-acetyl mannosamine (ManNAc). A knockdown of NPL in zebrafish resulted in severe skeletal myopathy and cardiac edema, mimicking the human phenotype. The phenotype was rescued by expression of wild-type human NPL but not by the p.Arg63Cys or p.Asn45Asp mutants. Importantly, the myopathy phenotype in zebrafish embryos was rescued by treatment with the catabolic products of NPL: N-acetyl glucosamine (GlcNAc) and ManNAc; the latter also rescuing the cardiac phenotype. In conclusion, we provide the first report to our knowledge of a human defect in sialic acid catabolism, which implicates an important role of the sialic acid catabolic pathway in mammalian muscle physiology, and suggests opportunities for monosaccharide replacement therapy in human patients.
Xiao-Yan Wen, Maja Tarailo-Graovac, Koroboshka Brand-Arzamendi, Anke Willems, Bojana Rakic, Karin Huijben, Afitz Da Silva, Xuefang Pan, Suzan El-Rass, Robin Ng, Katheryn Selby, Anju Mary Philip, Junghwa Yun, X. Cynthia Ye, Colin J. Ross, Anna M. Lehman, Fokje Zijlstra, N. Abu Bakar, Britt Drögemöller, Jacqueline Moreland, Wyeth W. Wasserman, Hilary Vallance, Monique van Scherpenzeel, Farhad Karbassi, Martin Hoskings, Udo Engelke, Arjan de Brouwer, Ron A. Wevers, Alexey V. Pshezhetsky, Clara D.M. van Karnebeek, Dirk J. Lefeber
Usage data is cumulative from September 2023 through September 2024.
Usage | JCI | PMC |
---|---|---|
Text version | 591 | 376 |
76 | 45 | |
Figure | 182 | 5 |
Supplemental data | 88 | 5 |
Citation downloads | 34 | 0 |
Totals | 971 | 431 |
Total Views | 1,402 |
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.