Expression of ILK in renal stroma is essential for multiple aspects of renal development

Kidney development involves reciprocal and inductive interactions between the ureteric bud (UB) and surrounding metanephric mesenchyme (MM). Signals from renal stromal lineages are essential for differentiation and patterning of renal epithelial and mesenchymal cell types, and renal vasculogenesis, however, underlying mechanisms remain not fully understood. Integrin-linked kinase (ILK), a key component of integrin signaling pathway, plays an important role in kidney development. However, the role of ILK in renal stroma remains unknown. Here, we ablated ILK in renal stromal lineages using a Pdgfrβ-Cre mouse line, and the resulting Ilk mutant mice presented postnatal growth retardation and died within 3 weeks of age with severe renal developmental defects. Pdgfrb-Cre;Ilk mutant kidneys exhibited a significant decrease in UB branching and disrupted collecting duct formation. From E16.5 onward, renal interstitium was disorganized, forming medullary interstitial pseudocysts. Pdgfrb-Cre;Ilk mutants exhibited re...