Although Type-2 (T2) induced epithelial dysfunction is likely to profoundly alter epithelial differentiation and repair in asthma, the mechanisms for these effects are poorly understood. A role for specific mucins, heavily N-glycosylated epithelial glycoproteins, in orchestrating epithelial cell fate in response to T2 stimuli has not previously been investigated. Levels of a sialylated MUC4β isoform were found to be increased in airway specimens from asthmatic patients, in association with T2 inflammation. We hypothesized that IL-13 would increase sialylation of MUC4β, thereby altering its function and that the β-galactoside α-2,6-sialyltranferase 1 (ST6GAL1) would regulate the sialylation. Using human biologic specimens and cultured primary human airway epithelial cells (HAECs), we demonstrated that IL-13 increased sialylation of MUC4β under control of ST6GAL1, and that both were increased in asthma, particularly in those with elevated T2 biomarkers. ST6GAL1 induced sialylation of MUC4β altered its lectin binding and secretion. Both ST6GAL1 and MUC4β inhibited epithelial cell proliferation while promoting goblet cell differentiation. These in vivo and in vitro data provide strong evidence for a critical role for ST6GAL1 induced sialylation of MUC4β in epithelial dysfunction associated with T2-High asthma, thereby identifying specific sialylation pathways as potential targets in asthma.
Xiuxia Zhou, Carol L. Kinlough, Rebecca P. Hughey, Mingzhu Jin, Hideki Inoue, Emily Etling, Brian D. Modena, Naftali Kaminski, Eugene R. Bleecker, Deborah A. Meyers, Nizar N. Jarjour, John B. Trudeau, Fernando Holguin, Anuradha Ray, Sally E. Wenzel
Guidelines: The Editorial Board will only consider letters that we deem relevant and of interest to our readers. We will not post data that have not been subjected to peer review, nor will we post letters that are essentially a reiteration of another letter. All accepted letters will be posted on our website within one week of acceptance. We reserve the right to edit any letter for length, content, and clarity. Authors of all accepted letters will be asked to preview any changes. Authors will be notified by e-mail if their letters were not accepted. As this is a final decision, no appeals will be considered.
Specific requirements: All letters must be 400 words or fewer. You may enter the letter as plain text or HTML. The author's name and e-mail address are required, and will be posted with the letter. All possible conflicts of interest must be noted, even if they are not posted. If you wish to include a figure (keep in mind that non-peer-reviewed data will not be posted), please contact the editors directly at email@example.com.