Integrin-Linked Kinase Regulates Integrin Signaling in

PURPOSE. To determine whether integrin-linked kinase (ILK) controls the organization of the actin cytoskeleton in the tra-becular meshwork (TM) by regulating integrin co-signaling. METHODS. The cell binding domain and the Heparin II (Hep II) domain of fibronectin were used to activate 51 and 41 integrin signaling, respectively, in differentiated human TM (HTM) cells. The role of ILK was determined using either ILK small interfering RNA (siRNA) to knockout ILK expression or the ILK inhibitors, KP392 and QLT0267. The knockdown of ILK expression was verified by Western blot analysis. The presence of actin stress fibers and focal adhesions was deter-mined by labeling cultures with phalloidin and anti-talin or ILK antibodies, respectively. RESULTS. Cell spreading in differentiated HTM cells required ILK, since ILK siRNA and the ILK inhibitors significantly re