Increased Expression of TGF-β Signaling Components in a Mouse Model of Fibrosis Induced by Submandibular Gland Duct Ligation.

Abstract

Transforming growth factor-β (TGF-β) is a multi-functional cytokine with a well-described role in the regulation of tissue fibrosis and regeneration in the liver, kidney and lung. Submandibular gland (SMG) duct ligation and subsequent deligation in rodents is a classical model for studying salivary gland damage and regeneration. While previous studies suggest that TGF-β may contribute to salivary gland fibrosis, the expression of TGF-β signaling components has not been investigated in relation to mouse SMG duct ligation-induced fibrosis and regeneration following ductal deligation. Following a 7 day SMG duct ligation, TGF-β1 and TGF-β3 were significantly upregulated in the SMG, as were TGF-β receptor 1 and downstream Smad family transcription factors in salivary acinar cells, but not in ductal cells. In acinar cells, duct ligation also led to upregulation of snail, a Smad-activated E-cadherin repressor and regulator of epithelial-mesenchymal transition, whereas in ductal cells upregulation of E-cadherin was observed while snail expression was unchanged. Upregulation of these TGF-β signaling components correlated with upregulation of fibrosis markers collagen 1 and fibronectin, responses that were inhibited by administration of the TGF-β receptor 1 inhibitors SB431542 or GW788388. After SMG regeneration following a 28 day duct deligation, TGF-β signaling components and epithelial-mesenchymal transition markers returned to levels similar to non-ligated controls. The results from this study indicate that increased TGF-β signaling contributes to duct ligation-induced changes in salivary epithelium that correlate with glandular fibrosis. Furthermore, the reversibility of enhanced TGF-β signaling in acinar cells of duct-ligated mouse SMG after deligation indicates that this is an ideal model for studying TGF-β signaling mechanisms in salivary epithelium as well as mechanisms of fibrosis initiation and their resolution.

• Authors: Lucas T Woods, Jean M Camden, Farid G El-Sayed, Mahmoud G Khalafalla, Michael J Petris, Laurie Erb, Gary A Weisman
• Journal: PloS one (PLoS One) Vol. 10 Issue 5 Pg. e0123641 ( 2015) ISSN: 1932-6203 [Electronic] United States
• PMID: 25955532 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• 4-(4-(3-(pyridin-2-yl)-1H-pyrazol-4-yl)pyridin-2-yl)-N-(tetrahydro-2H-pyran-4-yl)benzamide
• Benzamides
• Biomarkers
• Cadherins
• Protein Isoforms
• Pyrazoles
• Receptors, Transforming Growth Factor beta
• Smad Proteins
• Snail Family Transcription Factors
• Transcription Factors
• Transforming Growth Factor beta
• Protein Serine-Threonine Kinases
• Receptor, Transforming Growth Factor-beta Type I

Topics

• Acinar Cells (drug effects, metabolism, pathology)
• Animals
• Benzamides (pharmacology)
• Biomarkers (metabolism)
• Cadherins (genetics, metabolism)
• Disease Models, Animal
• Fibrosis
• Ligation
• Male
• Mice, Inbred C57BL
• Protein Isoforms (genetics, metabolism)
• Protein Serine-Threonine Kinases (genetics, metabolism)
• Pyrazoles (pharmacology)
• Receptor, Transforming Growth Factor-beta Type I
• Receptors, Transforming Growth Factor beta (genetics, metabolism)
• Regeneration (drug effects)
• Signal Transduction (drug effects, genetics)
• Smad Proteins (genetics, metabolism)
• Snail Family Transcription Factors
• Submandibular Gland (drug effects, metabolism, pathology)
• Transcription Factors (genetics, metabolism)
• Transforming Growth Factor beta (genetics, metabolism)
• Up-Regulation (genetics)