2026/02/06 by O.N. Hoang, Colin E Chan, Joshua M. Brenner +22 · 1 voice
Biochemistry, Genetics and Molecular Biology · Medicine · #Cellular transport and secretion #Glycosylation and Glycoproteins Research #Neonatal Respiratory Health Research
paper · doi:10.1093/ajrcmb/aanag018
openalex publication_date 2026/02/06 · openalex created_date 2026/02/22 · openalex updated_date 2026/08/01
RATIONALE: Finely tuned production and secretion of the polymeric mucins MUC5AC and MUCB are required for lung health, but knowledge of many details between their translation and their packaging into secretory granules is lacking. OBJECTIVES: To analyze the structure and function of the Golgi apparatus, a key site of mucin glycosylation, folding, polymerization, and packaging, in airway epithelial secretory cells. METHODS: Lung tissue was obtained from mice stimulated or not with IL-13 to upregulate mucin production and from normal human lungs. Golgi elements in mouse and human tissue were imaged by high-resolution immunofluorescence microscopy and electron microscopy. Tissue from mice with deletion of both polymeric mucins was also examined. MEASUREMENTS AND MAIN RESULTS: By immunofluorescence microscopy, both mouse and human airway secretory cells contained approximately 100 dispersed puncta labeled by markers of medial and trans-Golgi cisternae and the trans-Golgi network (TGN), but only a few perinuclear puncta were labeled by markers of cis-Golgi cisternae. By electron microscopy, secretory cells contained both a perinuclear Golgi ribbon and numerous dispersed Golgi stacks, termed satellites. In mucous metaplastic cells, satellites were concentrated among immature mucin granules. Increasing mucin production by cytokine stimulation did not increase the number of TGN puncta, nor did preventing polymeric mucin production by gene deletion reduce TGN puncta. CONCLUSIONS: Mucin-producing airway secretory cells express an unusual Golgi structure consisting of a conventional perinuclear ribbon as well as dispersed satellites. While the Golgi satellites are likely an adaptation for mucin production and packaging, their presence is specified developmentally, independent of mucin production.