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Expression of ETA and ETB receptor in adventitial fibroblasts
Author(s) -
Di Wang Hui,
Boyd Ryan,
Forgione Andrea
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.1148.8
Subject(s) - receptor , adventitia , endothelin receptor , angiotensin ii , receptor antagonist , extracellular matrix , endocrinology , medicine , chemistry , endothelin 1 , receptor expression , extracellular , antagonist , microbiology and biotechnology , biology
Objective: The adventitia has been recognized to play important roles in vascular remodeling and contraction. We recently demonstrated that adventitial fibroblasts are able to express endothelin‐1 (ET‐1) in response to angiotensin II (ANG II). However, it is unclear whether the ET‐1 receptors are expressed in the adventitia. We therefore examined the expression of both the ET A/B receptors and the roles of these two types of receptors in collagen synthesis and ET‐1 clearance in adventitial fibroblasts. Methods and Results: Adventitial fibroblasts were isolated and cultured from the thoracic mouse aorta. Cells were treated with ANG II (100 nM), the ET‐1 receptor antagonists (100 uM), BQ123 (ET A receptor) and/or BQ788 (ET B receptor). ET‐1 peptide levels were determined by ELISA, while ET A/B and collagen levels were determined by Western blot. ANG II increased ET A receptor protein as well as collagen in a similar fashion, reaching significance after 4, 6, and 24 hours treatment. ANG II induced collagen was reduced while in the presence of the ET A receptor antagonist suggesting the role of the ET A receptor in the regulation of the extracellular matrix. ANG II treatment also increased ET B receptor protein levels in time dependent manner. ANG II treatment in the presence of the ET B receptor antagonist significantly increased ET‐1 peptide levels, implicating the role of the ET B receptor in the clearance of the ET‐1 peptide. Conclusion: Both the ET A and ET B receptors are expressed in adventitial fibroblasts. The ET A receptor subtype mediates collagen I expression, while the ET B receptor may play a protective role through increasing the clearance of the ET‐1 peptide.