Tensin-1(TNS1)is a 220 kD focal adhesion protein that binds to actin filaments,integrin receptors,small GTPases,tyrosine-phosphorylated proteins,and lipids.1 These binding activities enable TNS1 to link the actin cytoskeleton to integrins and transduce outside-in and inside-out signals at focal adhesion sites,thereby regulating cell attachment,migration,prolif-eration,and mechanical sensing.

DLC1 is a focal adhesion molecule that regulates cell polarity, proliferation, migration, and survival. DLC1 functions as a tumor suppressor and its expression is often down-regulated in various malignant neoplasms of epithelial origin. Recent studies have suggested that lack of DLC1 in endothelial cells may contribute to the development of angiosarcoma, and that DLC1 mutations have been identified in patients with nephrotic syndrome, a disease mainly due to leaky glomerular filtration barriers. To demonstrate whether lack of endothelial DLC1 induces angiosarcoma and/or damages glomerular capillaries leading to nephrotic syndrome, we have extended our analyses on endothelial cell-specific DLC1 knockout mice with focuses on their liver and kidney function. Mice were monitored up to 24 months of age. However, no histological or clinical difference was found between DLC1 knockout and wild type mice, indicating that lack of endothelial DLC1 alone does not compromise kidney and liver function in mice.