Hway is critical to vascular development, repair, and remodeling [15,16,17,18]. Recently, Notch signaling has been shown to be downregulated in human abdominal aortic aneurysm (AAA) tissue [19] and in the ascending aorta of patients with bicuspidNotch Signaling in Aortic Aneurysm and Dissectionaortic valve (BAV) [20]. Furthermore, genetic variation in 
the NOTCH1 gene appears to confer susceptibility to ascending aortic aneurysm formation in patients with BAV [21]. However, Notch signaling has not been examined in sporadic descending thoracic aortic aneurysm and dissection (DTAAD). Because of its important role in vascular repair and remodeling, we hypothesize that Notch signaling may be altered in DTAAD. In this study, we examined the activation of the Notch signaling pathway in aortic tissue from patients with DTAAD.Western blotFrozen aortic tissues (approximately 100 mg) were ground and homogenized. Protein content was extracted with RIPA buffer (Cell Signaling Technology, Danvers, MA), and protein concentration was determined by using the Bradford assay (Bio-Rad Laboratories, Hercules, CA). A total of 20 mg protein was electrophoretically separated in 4?0 Homotaurine chemical information Mini-PROTEAN TGX Gels (Bio-Rad Laboratories) and transferred onto polyvinylidene difluoride membranes (Bio-Rad Laboratories). Anti-Notch1 rabbit monoclonal antibody (1:1000, Cell Signaling Technology), anticleaved Notch1 rabbit monoclonal antibody (1:1000, Cell Signaling Technology), Hexaconazole custom synthesis anti-Hes1 polyclonal antibody (1:1000, EMD Millipore, Billerica, MA), and a horseradish peroxidaselabeled anti-rabbit secondary antibody (1:5000, Santa Cruz Biotechnology, Santa Cruz, CA) were used to detect Notch1, NICD, and Hes1 proteins in the extract. An anti-b-actin mouse monoclonal antibody (1:5000; Cell Signaling Technology) was used to confirm equal loading. Detailed information on the primary antibodies is provided in Table 2. The western blot bands were scanned and analyzed by using ImageJ software (National Institutes of Health).Materials and Methods Patient enrollment and tissue collectionThis study protocol was approved by the institutional review board at Baylor College of Medicine. Informed, written consent was obtained from all patients. We enrolled patients who underwent elective surgical repair of either a descending thoracic 
aortic aneurysm without dissection (TAA) or a chronic descending thoracic aortic dissection (TAD). We excluded patients who had acute symptoms (,14 days); BAV; heritable connective tissue disease (eg, Marfan syndrome); DTAAD related to trauma, aortitis, or infection; and first-degree relatives who had TAA or TAD. We obtained samples of aortic 24786787 tissue from 30 DTAAD patients undergoing surgical repair: TAA patients (n = 14) and TAD patients (n = 16). In the latter group, the mean interval between the onset of dissection and operation was 5.164.5 years. During TAA and TAD repair, samples of the posterolateral aortic wall were excised from the site of maximal aortic dilatation; in cases of aortic dissection, these samples comprised the outer wall of the false lumen. After excision, samples were rinsed with cold saline, and any attached thrombus was removed. Control samples (International Institute for the Advancement of Medicine, Jessup, PA) of descending thoracic aortic tissue were obtained from 12 age-matched organ donors without aortic aneurysm, dissection, coarctation, or previous aortic repair. For protein extraction, tissues were snap-frozen in liquid nitrogen a.Hway is critical to vascular development, repair, and remodeling [15,16,17,18]. Recently, Notch signaling has been shown to be downregulated in human abdominal aortic aneurysm (AAA) tissue [19] and in the ascending aorta of patients with bicuspidNotch Signaling in Aortic Aneurysm and Dissectionaortic valve (BAV) [20]. Furthermore, genetic variation in the NOTCH1 gene appears to confer susceptibility to ascending aortic aneurysm formation in patients with BAV [21]. However, Notch signaling has not been examined in sporadic descending thoracic aortic aneurysm and dissection (DTAAD). Because of its important role in vascular repair and remodeling, we hypothesize that Notch signaling may be altered in DTAAD. In this study, we examined the activation of the Notch signaling pathway in aortic tissue from patients with DTAAD.Western blotFrozen aortic tissues (approximately 100 mg) were ground and homogenized. Protein content was extracted with RIPA buffer (Cell Signaling Technology, Danvers, MA), and protein concentration was determined by using the Bradford assay (Bio-Rad Laboratories, Hercules, CA). A total of 20 mg protein was electrophoretically separated in 4?0 Mini-PROTEAN TGX Gels (Bio-Rad Laboratories) and transferred onto polyvinylidene difluoride membranes (Bio-Rad Laboratories). Anti-Notch1 rabbit monoclonal antibody (1:1000, Cell Signaling Technology), anticleaved Notch1 rabbit monoclonal antibody (1:1000, Cell Signaling Technology), anti-Hes1 polyclonal antibody (1:1000, EMD Millipore, Billerica, MA), and a horseradish peroxidaselabeled anti-rabbit secondary antibody (1:5000, Santa Cruz Biotechnology, Santa Cruz, CA) were used to detect Notch1, NICD, and Hes1 proteins in the extract. An anti-b-actin mouse monoclonal antibody (1:5000; Cell Signaling Technology) was used to confirm equal loading. Detailed information on the primary antibodies is provided in Table 2. The western blot bands were scanned and analyzed by using ImageJ software (National Institutes of Health).Materials and Methods Patient enrollment and tissue collectionThis study protocol was approved by the institutional review board at Baylor College of Medicine. Informed, written consent was obtained from all patients. We enrolled patients who underwent elective surgical repair of either a descending thoracic aortic aneurysm without dissection (TAA) or a chronic descending thoracic aortic dissection (TAD). We excluded patients who had acute symptoms (,14 days); BAV; heritable connective tissue disease (eg, Marfan syndrome); DTAAD related to trauma, aortitis, or infection; and first-degree relatives who had TAA or TAD. We obtained samples of aortic 24786787 tissue from 30 DTAAD patients undergoing surgical repair: TAA patients (n = 14) and TAD patients (n = 16). In the latter group, the mean interval between the onset of dissection and operation was 5.164.5 years. During TAA and TAD repair, samples of the posterolateral aortic wall were excised from the site of maximal aortic dilatation; in cases of aortic dissection, these samples comprised the outer wall of the false lumen. After excision, samples were rinsed with cold saline, and any attached thrombus was removed. Control samples (International Institute for the Advancement of Medicine, Jessup, PA) of descending thoracic aortic tissue were obtained from 12 age-matched organ donors without aortic aneurysm, dissection, coarctation, or previous aortic repair. For protein extraction, tissues were snap-frozen in liquid nitrogen a.
