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Updated: Mar 27, 2026
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Isolation of Human Lymphatic Endothelial Cells by Multi-parameter Fluorescence-activated Cell Sorting
Published on: May 1, 2015
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Lymphatic Malformations With Activating KRAS Mutations Impair Lymphatic Valve Development Through Matrix
Diandra M Mastrogiacomo1, Abbigail Price1, Yuting Fu1
1Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa (D.M.M., A.P., Y.F., R.B., L.A.K., K.L., Y.Y., G.E.D., J.P.S.).
Arteriosclerosis, Thrombosis, and Vascular Biology
|March 26, 2026
Summary
Activating KRAS mutations cause lymphatic valve loss by upregulating matrix metalloproteinases (MMPs) that degrade the valve's extracellular matrix. Inhibiting MMPs rescues lymphatic valve development, revealing a key mechanism in lymphatic malformations.
Area of Science:
- Vascular biology
- Molecular mechanisms of disease
- Lymphatic system development
Background:
- Lymphatic malformations result from genetic mutations affecting lymphatic vasculature.
- Activating KRAS mutations are linked to lymphatic malformations and associated conditions like lymphedema and chylothorax.
- The precise mechanisms causing lymphatic valve loss in these conditions remain unclear.
Purpose of the Study:
- To elucidate the molecular mechanisms underlying lymphatic valve loss in the context of KRAS mutations.
- To investigate the role of specific signaling pathways and enzymes in lymphatic valve development and degradation.
Main Methods:
- Utilized a mouse model with lymphatic-specific, inducible KRAS-G12D expression and a Prox1GFP reporter.
- Analyzed human dermal lymphatic endothelial cells (HDLECs) with KRAS-G12D expression using qPCR, Western blot, and gel zymography.
- Performed mechanistic studies in 3D collagen matrices and tested MMP inhibitors in vivo.
Main Results:
- Lymphatic-specific KRAS-G12D expression attenuated lymphatic valve development in mice.
- KRAS-G12D induced upregulation of the plasminogen activator (PA) pathway and matrix metalloproteinases (MMPs) in HDLECs.
- MMPs, activated by plasmin, degraded the extracellular matrix (ECM) core of lymphatic valves, and MMP inhibition rescued valve formation.
Conclusions:
- Hyperactive KRAS signaling promotes lymphatic valve loss through MMP-mediated ECM degradation.
- The PA pathway plays a crucial role in activating MMPs involved in valve development.
- Targeting MMPs represents a potential therapeutic strategy for lymphatic malformations.
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