Cellular and molecular architecture of submucosal glands in wild-type and cystic fibrosis pigs

Abstract

Submucosal glands (SMGs) protect lungs but can also contribute to disease. For example, in cystic fibrosis (CF), SMGs produce abnormal mucus that disrupts mucociliary transport. CF is an ion transport disease, yet knowledge of the ion transporters expressed by SMG acini, which produce mucus, and SMG ducts that carry it to the airway lumen is limited. Therefore, we isolated SMGs from newborn pigs and used single-cell messenger RNA sequencing, immunohistochemistry, and in situ hybridization to identify cell types, gene expression, and spatial distribution. Cell types and transcript levels were the same in non-CF and CF SMGs, suggesting that loss of epithelial anion secretion rather than an intrinsic cell defect causes CF mucus abnormalities. Gene signatures of acinar mucous and acinar serous cells revealed specialized functions in producing mucins and antimicrobials, respectively. However, surprisingly, these two cell types expressed the same ion transporters and neurohumoral receptors, suggesting the importance of balancing mucin and liquid secretion to produce optimal mucus properties. SMG duct cell transcripts suggest that they secrete HCO3− and Cl−, and thus have some similarity to pancreatic ducts that are also defective in CF. These and additional findings suggest the functions of the SMG acinus and duct and provide a baseline for understanding how environmental and genetic challenges impact their contribution to lung disease.

An optimized approach and inflation media for obtaining complimentary mass spectrometry-based omics data from human lung tissue

“…To identify potential proteins that may specifically correlate with the PG spatial localization we could see with MALDI-MSI, LCM was utilized to specifically isolate and analyze these airway structures. Importantly, numerous markers of airway epithelial cells ( Sun et al, 2022 ) were detected in the microdissected regions including: the well-described marker of secretory cells uteroglobin (SCGB1A1) ( Zhu et al, 2019 ); RSPH1 that localizes within the cilia of airway epithelial cells ( Kott et al, 2013 ); the recently described basal marker TACSTD2 ( Lenárt et al, 2021 ; Sun et al, 2022 ), the neuroendocrine marker GRP ( Wang and Conlon, 1993 ), the myoepithelial cell marker MYH11 ( Anderson et al, 2017 ) and the serous cell markers LYZ ( Yu et al, 2022 )and LTF ( Travaglini et al, 2020 ). The data showed the presence of surfactant proteins (SP).…”

Cell type catalog of middle turbinate epithelium

“…We broadly categorized 5 serous clusters into 2 groups (Figure 5A-B). Although several of the marker genes aforementioned showed a similar expression pattern in all subgroups (Supplemental Figure 4), only Serous1-3 expressed DMBT1 at a high level (Figure 5C); this protein is a known marker of serous cells 37 and has been identified in serous acini cells in human (which was not certified by peer review) is the author/funder. All rights reserved.…”

“…[33][34][35][36] BPIFB2 has also been shown to be highly expressed in goblet cells in pig submucosal glands. 37,38 We found a cluster characterized by expression of these genes (Figure 3), which identified this cluster as goblet cells. Some of these genes (MUC5B, TFF1, and TFF3) were previously shown to be over-expressed in middle turbinate samples from patients with CRS.…”

Insights gained in the pathology of lung disease through single‐cell transcriptomics

“…A single‐cell transcriptomic analysis of the submucosal gland in newborn pigs has recently been performed, both in CF and non‐CF animals [51]. This work suggests that loss of epithelial anion secretion, rather than intrinsic cell defects, might be involved in CF‐related mucociliary abnormalities.…”