ET-3/ETBR Mediates Na⁺-Activated Immune Signaling and Kidney Lymphatic Dynamics

Area of Science:

• Nephrology
• Immunology
• Vascular Biology

Background:

• Kidney lymphatic vessels are crucial for fluid and immune cell clearance.
• Dysfunctional lymphatics worsen kidney injury and inflammation.
• Sodium accumulation in kidney injury stimulates inflammatory responses.

Purpose of the Study:

• Investigate isolevuglandin-adduct formation in kidney injury.
• Determine effects on lymphatic endothelial cells (LECs).
• Elucidate the role of the endothelin-3 (ET-3)/endothelin type B receptor (ETBR) axis in lymphatic function.

Main Methods:

• Used a mouse model of nephrotoxin-induced proteinuric kidney injury.
• Analyzed immune cell-LEC interactions via transwell assays, RNA sequencing, and flow cytometry.
• Assessed lymphatic vessel contractility using a vessel perfusion chamber.

Main Results:

• Proteinuric injury increased kidney lymphangiogenesis and immune cell infiltration (dendritic cells, T cells).
• Sodium-rich environments enhanced LEC-immune cell interaction and LEC isolevuglandin-adduct production.
• Isolevuglandin-adducts facilitated ET-3/ETBR signaling, modulating lymphatic vessel pumping.

Conclusions:

• A novel mechanism links isolevuglandins, the ET-3/ETBR axis, LECs, and dendritic cells in kidney injury.
• ET-3/ETBR signaling is a new pathogenic factor in lymphatic vessel dynamics during kidney disease.
• The ET-3/ETBR axis represents a potential therapeutic target for kidney diseases.