Caveolin Delivered by Ultrasound-Mediated Microbubble Destruction Prevents Endothelial Cell Proliferation.

Introduction: The nitric oxide synthase (eNOS) is an important regulator of vascular homeostasis. eNOS is modulated by intracellular mechanisms that include protein-protein interaction with Caveolin-1 (Cav). Cav binds to and impairs eNOS activation reducing vascular permeability and angiogenesis. Blocking of eNOS by Cav has been proposed as therapeutic antiangiogenic approach. However, the efficient and controlled delivery of the peptide requires to be solved. Methods: The effect of antennapedia (AP)-Cav loaded into microbubbles (MBs) and delivered by ultrasound-mediated microbubble destruction (UMMD) into brain endothelial cells (bEnd.3 cells) was evaluated on NO production using DAF2-DA, cell migration assessed by the wound healing assay, cell proliferation with BrdU, and ex-vivo angiogenesis in rat aortic rings. Results: An enhanced inhibitory effect of AP-Cav was observed on cells treated with UMMD. MBs and ultrasound disruption delivery of AP-Cav increased acetylcholine-induced NO release, wound healing, cell proliferation, and angiogenesis inhibition on bEnd.3 cells, compared to free AP-Cav administration. Conclusion: We demonstrated that the delivery of Cav via AP-Cav-loaded MBs and UMMD may be an administration method for Cav that would increase its therapeutic potential by enhancing efficacy and cellular specificity.

Thromboxane-dependent coronary vasoconstriction in obese mice: Role of peroxynitrite.

Obesity leads to chronic oxidative stress promoting the development of cardiovascular diseases including coronary artery disease and endothelial dysfunction. Increased reactive oxygen species production associated with obesity might lead to endothelial dysfunction through cyclooxygenase (COX) pathway. We evaluated arachidonic acid (AA)-dependent coronary vascular responses and explored COX metabolism in obese C57BL/6 mice. In response to arachidonic acid (AA), isolated hearts from obese mice showed increased vasoconstriction compared with control mice. Released thromboxane (TX) A2 during AA-induced vasoconstriction phase was increased in heart perfusates from obese mice. Indomethacin and 1-benzylimidazole, both reduced vasoconstriction response in control and obese mice. Vasoconstriction response to TXA2 mimetic analog U46619 was 2.7 higher in obese mice. Obesity increased COX-2, TXS and TX receptor protein expression as well as oxidative stress evaluated by nitrotyrosine and peroxynitrite levels, compared with control mice. Obese mice treated with FeTMPyP, a peroxynitrite scavenger, reversed all these parameters to control levels. These data suggest that alterations in COX pathway may be associated with increased generation of free radicals, including peroxynitrite, that result from the oxidative stress observed in obesity.