Wnt/β-catenin signaling and kidney fibrosis

Wnt/beta-catenin signaling is an evolutionarily conserved, highly complex, key developmental pathway that regulates cell fate, organ development, tissue homeostasis, as well as injury and repair. Although relatively silent in normal adult kidney, Wnt/beta-catenin signaling is re-activated after renal injury in a wide variety of animal models and in human kidney disorders. Whereas some data point to a protective role of this signaling in healing and repair after acute kidney injury, increasing evidence suggests that sustained activation of Wnt/beta-catenin is associated with the development and progression of renal fibrotic lesions. In kidney cells, Wnt/beta-catenin promotes the expression of numerous fibrosis-related genes such as Snail1, plasminogen activator inhibitor-1, and matrix metalloproteinase-7. Recent studies also indicate that multiple components of the renin-angiotensin system are the direct downstream targets of Wnt/beta-catenin. Consistently, inhibition of Wnt/beta-catenin signaling by an assortment of strategies ameliorates kidney injury and mitigates renal fibrotic lesions in various models of chronic kidney disease, suggesting that targeting this signaling could be a plausible strategy for therapeutic intervention. In this mini review, we will briefly discuss the regulation, downstream targets, and mechanisms of Wnt/beta-catenin signaling in the pathogenesis of kidney fibrosis.