BACKGROUND: Estrogen receptor alpha (ERα) has been identified in the vessel wall, offering vasoprotective effects when upregulated. Estrogens are known to mediate the inflammatory milieu, and inflammation has long been associated with abdominal aortic aneurysm (AAA) formation. Therefore, it is theorized that increased estrogen receptor in females contributes to their relative resistance to AAAs. The objective of this study was to determine gender differences in ERα levels during experimental AAA formation. METHODS: Infrarenal aortas of male and female C57 mice (n = 18 and n = 16, respectively) were infused with 0.4% elastase. Diameters were measured at days 0 and 14. Aortic messenger RNA expression of ERα was determined on day 3 by reverse transcription-polymerase chain reaction, whereas ERα protein levels were measured via Western blot. Immunohistochemistry using rabbit antibody for ERα was performed on day 14 samples and quantified. Zymography was done for matrix metalloproteinases (MMP)2 and 9 activity levels. Samples of human AAAs were collected and Western blot performed. Data were compared for significance using a student t-test. RESULTS: Infrarenal aortic diameter increased in elastase-perfused males (ME) by 80% at 14 days after perfusion, whereas females (FE) increased by only 35% (P = 0.0012). FE had ×10 greater ERα messenger RNA expression compared with ME at day 3 (P = 0.003). Similarly, ERα protein levels were 100% higher in FE compared with those in ME on day 14 (P = 0.035). ERα protein levels were 80% higher in female human patients with AAA than those in their male counterparts (P = 0.029). ERα visualized via immunohistochemistry was 1.5 fold higher in FE than ME (P = 0.029). MMP2 and 9 activity levels were decreased in female compared with male aortas. CONCLUSIONS: This study demonstrates an increase in aortic wall ERα in females compared with males that correlates inversely with MMP activity and AAA formation. These findings, coupled with observations that exogenous estrogen inhibits AAA formation in males, further suggest that estrogen supplementation may be important to prevent AAA formation and growth.
BACKGROUND:Estrogen receptor alpha (ERα) has been identified in the vessel wall, offering vasoprotective effects when upregulated. Estrogens are known to mediate the inflammatory milieu, and inflammation has long been associated with abdominal aortic aneurysm (AAA) formation. Therefore, it is theorized that increased estrogen receptor in females contributes to their relative resistance to AAAs. The objective of this study was to determine gender differences in ERα levels during experimental AAA formation. METHODS: Infrarenal aortas of male and female C57 mice (n = 18 and n = 16, respectively) were infused with 0.4% elastase. Diameters were measured at days 0 and 14. Aortic messenger RNA expression of ERα was determined on day 3 by reverse transcription-polymerase chain reaction, whereas ERα protein levels were measured via Western blot. Immunohistochemistry using rabbit antibody for ERα was performed on day 14 samples and quantified. Zymography was done for matrix metalloproteinases (MMP)2 and 9 activity levels. Samples of human AAAs were collected and Western blot performed. Data were compared for significance using a student t-test. RESULTS: Infrarenal aortic diameter increased in elastase-perfused males (ME) by 80% at 14 days after perfusion, whereas females (FE) increased by only 35% (P = 0.0012). FE had ×10 greater ERα messenger RNA expression compared with ME at day 3 (P = 0.003). Similarly, ERα protein levels were 100% higher in FE compared with those in ME on day 14 (P = 0.035). ERα protein levels were 80% higher in female humanpatients with AAA than those in their male counterparts (P = 0.029). ERα visualized via immunohistochemistry was 1.5 fold higher in FE than ME (P = 0.029). MMP2 and 9 activity levels were decreased in female compared with male aortas. CONCLUSIONS: This study demonstrates an increase in aortic wall ERα in females compared with males that correlates inversely with MMP activity and AAA formation. These findings, coupled with observations that exogenous estrogen inhibits AAA formation in males, further suggest that estrogen supplementation may be important to prevent AAA formation and growth.
Authors: Gary Pare; Andrée Krust; Richard H Karas; Sonia Dupont; Mark Aronovitz; Pierre Chambon; Michael E Mendelsohn Journal: Circ Res Date: 2002-05-31 Impact factor: 17.367
Authors: M D Iafrati; R H Karas; M Aronovitz; S Kim; T R Sullivan; D B Lubahn; T F O'Donnell; K S Korach; M E Mendelsohn Journal: Nat Med Date: 1997-05 Impact factor: 53.440
Authors: E Enmark; M Pelto-Huikko; K Grandien; S Lagercrantz; J Lagercrantz; G Fried; M Nordenskjöld; J A Gustafsson Journal: J Clin Endocrinol Metab Date: 1997-12 Impact factor: 5.958
Authors: D B Lubahn; J S Moyer; T S Golding; J F Couse; K S Korach; O Smithies Journal: Proc Natl Acad Sci U S A Date: 1993-12-01 Impact factor: 11.205
Authors: Peggy Robinet; Dianna M Milewicz; Lisa A Cassis; Nicholas J Leeper; Hong S Lu; Jonathan D Smith Journal: Arterioscler Thromb Vasc Biol Date: 2018-01-04 Impact factor: 8.311
Authors: Adriana G Ramirez; Nolan A Wages; Yinin Hu; Mark E Smolkin; Craig L Slingluff Journal: Cancer Immunol Immunother Date: 2015-09-21 Impact factor: 6.968
Authors: Ye Yao; Junli Zhuang; You Li; Bao Jing; Hali Li; Jingbo Li; Changgang Shao; Keshen Li; Haiyang Wang Journal: Biomed Res Int Date: 2015-02-18 Impact factor: 3.411