Reactive oxygen species production via NADPH oxidase mediates TGF- -induced cytoskeletal alterations in endothelial cells

Hu, Taishan, Satish P. RamachandraRao, Senthuran Siva, Cathryn Valancius, Yanqing Zhu, Kalyankar Mahadev, Irene Toh, Barry J. Goldstein, Marilyn Woolkalis, and Kumar Sharma. Reactive oxygen species production via NADPH oxidase mediates TGF-induced cytoskeletal alterations in endothelial cells. Am J Physiol Renal Physiol 289: F816–F825, 2005; doi:10.1152/ajprenal.00024.2005.—Cytoskeletal alterations in endothelial cells have been linked to nitric oxide generation and cell-cell interactions. Transforming growth factor (TGF)has been described to affect cytoskeletal rearrangement in numerous cell types; however, the underlying pathway is unclear. In the present study, we found that human umbilical vein endothelial cells (HUVEC) have marked cytoskeletal alterations with short-term TGFtreatment resulting in filipodia formation and F-actin assembly. The cytoskeletal alterations were blocked by the novel TGFtype I receptor/ALK5 kinase inhibitor (SB-505124) but not by the p38 kinase inhibitor (SB-203580). TGFalso induced marked stimulation of reactive oxygen species (ROS) within 5 min of TGFexposure. TGFstimulation of ROS was mediated by the NAPDH oxidase homolog Nox4 as DPI, an inhibitor of NADPH oxidase, and dominant-negative Nox4 adenovirus blocked ROS production. Finally, inhibition of ROS with ROS scavengers or dominant-negative Nox4 blocked the TGFeffect on cytoskeleton changes in endothelial cells. In conclusion, our studies show for the first time that TGF-induced ROS production in human endothelial cells is via Nox4 and that TGFalteration of cytoskeleton in HUVEC is mediated via a Nox4-dependent pathway.