CXCR6 Plays a Critical Role in Angiotensin II–Induced Renal Injury and FibrosisSignificance
Objective—Recent studies have shown that angiotensin II (Ang II) plays a critical role in the pathogenesis and progression of hypertensive kidney disease. However, the signaling mechanisms are poorly understood. In this study, we investigated the role of CXCR6 in Ang II–induced renal injury and fibrosis.
Approach and Results—Wild-type and CXCR6-green fluorescent protein (GFP) knockin mice were treated with Ang II via subcutaneous osmotic minipumps at 1500 ng/kg per minute after unilateral nephrectomy for ≤4 weeks. Wild-type and CXCR6-GFP knockin mice had virtually identical blood pressure at baseline. Ang II treatment led to an increase in blood pressure that was similar between wild-type and CXCR6-GFP knockin mice. CXCR6-GFP knockin mice were protected from Ang II–induced renal dysfunction, proteinuria, and fibrosis. CXCR6-GFP knockin mice accumulated fewer bone marrow–derived fibroblasts and myofibroblasts and produced less extracellular matrix protein in the kidneys after Ang II treatment. Furthermore, CXCR6-GFP knockin mice exhibited fewer F4/80+ macrophages and CD3+ T cells and expressed less proinflammatory cytokines in the kidneys after Ang II treatment. Finally, wild-type mice engrafted with CXCR6−/− bone marrow cells displayed fewer bone marrow–derived fibroblasts, macrophages, and T cells in the kidney after Ang II treatment when compared with wild-type mice engrafted with CXCR6+/+ bone marrow cells.
Conclusions—Our results indicate that CXCR6 plays a pivotal role in the development of Ang II–induced renal injury and fibrosis through regulation of macrophage and T-cell infiltration and bone marrow–derived fibroblast accumulation.
- Received March 11, 2013.
- Accepted May 11, 2014.
- © 2014 American Heart Association, Inc.