MT2-MMP-dependent release of collagen IV NC1 domains regulates submandibular gland branching morphogenesis.
Proteolysis is essential during branching morphogenesis, but the roles of MT-MMPs and their proteolytic products are not clearly understood. Here, we discover that decreasing MT-MMP activity during submandibular gland branching morphogenesis decreases proliferation and increases collagen IV and MT-MMP expression. Specifically, reducing epithelial MT2-MMP profoundly decreases proliferation and morphogenesis, increases Col4a2 and intracellular accumulation of collagen IV, and decreases the proteolytic release of collagen IV NC1 domains. Importantly, we demonstrate the presence of collagen IV NC1 domains in developing tissue. Furthermore, recombinant collagen IV NC1 domains rescue branching morphogenesis after MT2-siRNA treatment, increasing MT-MMP and proproliferative gene expression via beta1 integrin and PI3K-AKT signaling. Additionally, HBEGF also rescues MT2-siRNA treatment, increasing NC1 domain release, proliferation, and MT2-MMP and Hbegf expression. Our studies provide mechanistic insight into how MT2-MMP-dependent release of bioactive NC1 domains from collagen IV is critical for integrating collagen IV synthesis and proteolysis with epithelial proliferation during branching morphogenesis.
Rebustini
Ivan T
IT
Matrix and Morphogenesis Unit, Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Drive, Bethesda, MD 20892, USA.
Myers
Christopher
C
Lassiter
Keyonica S
KS
Surmak
Andrew
A
Szabova
Ludmila
L
Holmbeck
Kenn
K
Pedchenko
Vadim
V
Hudson
Billy G
BG
Hoffman
Matthew P
MP
D000818:Animals; D015153:Blotting, Western; D049109:Cell Proliferation; D024141:Collagen Type IV / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006493:Heparin / Q000378:metabolism; D066257:Heparin-binding EGF-like Growth Factor; D047468:Immunoprecipitation; D019012:Integrin beta1 / Q000235:genetics / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D053511:Matrix Metalloproteinase 14 / Q000502:physiology*; D053517:Matrix Metalloproteinase 15 / Q000235:genetics / Q000378:metabolism*; D061965:Matrix Metalloproteinase Inhibitors; D051379:Mice; D018345:Mice, Knockout; D009024:Morphogenesis; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013363:Submandibular Gland / Q000254:growth & development* / Q000378:metabolism*
D024141:Collagen Type IV; C587884:Hbegf protein, mouse; D066257:Heparin-binding EGF-like Growth Factor; D019012:Integrin beta1; D036341:Intercellular Signaling Peptides and Proteins; D061965:Matrix Metalloproteinase Inhibitors; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D006493:Heparin; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D053517:Matrix Metalloproteinase 15; D053511:Matrix Metalloproteinase 14