Figure 7.

KIBRA regulated cell migration of podocytes. (A) A wound was scraped into confluent cell culture monolayers of control and KIBRA k/d podocytes (top, 0 h). In contrast to control cells, KIBRA k/d podocytes are incapable of closing a wound within 10 h via directed migration (bottom, 10 h). Square fields of identical size were superimposed to count cells that had migrated into the wound area. Bar = 50 μm. (B) The number of cells that had migrated into equal areas within 10 h was plotted (square fields in A). KIBRA k/d podocytes are severely impaired in migrating into the denuded area. Experiments were performed in triplicate. (C) Typical original trajectories of control and KIBRA k/d cells are superimposed on the starting images of wound-healing assays. Migration of control podocytes is characterized by a high degree of persistence, and cells rarely change the direction of migration (left). In contrast, KIBRA k/d podocyte migration is ineffective and direction of movement changes frequently (right). (D) Statistical evaluation of migration velocity and displacement. KIBRA k/d podocytes move significantly faster (P < 0.05; P = 0.01) than control cells. Despite the higher velocity of KIBRA k/d podocytes, their displacement (Ø 152.8 ± 22.9 μm) is not significantly different (P = 0.09) from that of control cells (Ø 112.8 ± 7.0 μm). This can be accounted for by the frequent turns in the direction of movement of KIBRA k/d cells. Means of 21 (control) or 17 (KIBRA k/d) cells are given.