Nephrin phosphorylation regulates podocyte adhesion through the PINCH-1-ILK-α-parvin complex

Abstract

Nephrin, a structural molecule, is also a signaling molecule afterphosphorylation. Inhibition of nephrin phosphorylation iscorrelated with podocyte injury. The PINCH-1-ILK-α-parvin(PIP) complex plays a crucial role in cell adhesion andcytoskeleton formation. We hypothesized that nephrinphosphorylation influenced cytoskeleton and cell adhesion inpodocytes by regulating the PIP complex. The nephrinphosphorylation, PIP complex formation, and F-actin in Wistarrats intraperitoneally injected with puromycin aminonucleosidewere gradually decreased but increased with time, coincidingwith the recovery from glomerular/podocyte injury and proteinuria.In cultured podocytes, PIP complex knockdown resultedin cytoskeleton reorganization and decreased cell adhesion andspreading. Nephrin and its phosphorylation were unaffectedafter PIP complex knockdown. Furthermore, inhibition ofnephrin phosphorylation suppressed PIP complex expression,disorganized podocyte cytoskeleton, and decreased celladhesion and spreading. These findings indicate that alterationsin nephrin phosphorylation disorganize podocyte cytoskeletonand decrease cell adhesion through a PIP complex-dependentmechanism. [BMB Reports 2013; 46(4): 230-235]

Keywords

• Cell adhesion
• Nephrin phosphorylation
• PINCH-1-ILK-α-parvin complex
• Podocyte