| First Author | Wisler JW | Year | 2015 |
| Journal | Am J Physiol Heart Circ Physiol | Volume | 309 |
| Issue | 9 | Pages | H1516-27 |
| PubMed ID | 26371162 | Mgi Jnum | J:230673 |
| Mgi Id | MGI:5763526 | Doi | 10.1152/ajpheart.00291.2015 |
| Citation | Wisler JW, et al. (2015) The role of beta-arrestin2-dependent signaling in thoracic aortic aneurysm formation in a murine model of Marfan syndrome. Am J Physiol Heart Circ Physiol 309(9):H1516-27 |
| abstractText | Ang II type 1a receptor (AT1aR)-mediated activation of MAPKs contributes to thoracic aortic aneurysm (TAA) development in Marfan syndrome (MFS). beta-Arrestin2 (betaarr2) is known to mediate AT1aR-dependent MAPK activation, as well as proproliferative and profibrotic signaling in aortic vascular smooth muscle cells. Therefore, we investigated whether betaarr2-dependent signaling contributes to TAA formation in MFS. We used a murine model of MFS [fibrillin (Fbn)(C1039G/+)] to generate an MFS murine model in combination with genetic betaarr2 deletion (Fbn(C1039G/+)/betaarr2(-/-)). Fbn(C1039G/+)/betaarr2(-/-) mice displayed delayed aortic root dilation compared with Fbn(C1039G/+) mice. The mRNA and protein expression of several mediators of TAA formation, including matrix metalloproteinase (MMP)-2 and -9, was reduced in the aorta of Fbn(C1039G/+)/betaarr2(-/-) mice relative to Fbn(C1039G/+) mice. Activation of ERK1/2 was also decreased in the aortas of Fbn(C1039G/+)/betaarr2(-/-) mice compared with Fbn(C1039G/+) animals. Small interfering RNA targeting betaarr2 inhibited angiotensin-stimulated expression of proaneurysmal signaling mediators in primary aortic root smooth muscle cells. Angiotensin-stimulated expression of the proaneurysmal signaling mediators MMP-2 and -9 was inhibited by blockade of ERK1/2 or the EGF receptor, whereas blockade of the transforming growth factor-beta receptor had no effect. These results suggest that betaarr2 contributes to TAA formation in MFS by regulating ERK1/2-dependent expression of proaneurysmal genes and proteins downstream of the AT1aR. Importantly, this demonstration of the unique signaling mechanism by which betaarr2 contributes to aneurysm formation identifies multiple novel, potential therapeutic targets in MFS. |
