In an attempt to identify proteins that could potentially be involved in differentiation of vascular adventitial myofibroblasts (MF), proteomic differential expression profile after stimulation to vascular adventitial fibroblasts (AF) with angiotensin II (Ang II) and transforming growth factor-beta 1 (TGF-β1) was investigated using two-dimensional electrophoresis (2D-E) and mass spectrometry. 41 protein spots with sig-nificant difference were identified. 14 of them were regulated obviously in abundance and/or position by both Ang II and TGF-β1. Among 14 spots, 4 protein spots were increased in abundance and that of other 6 spots were down-regulated. 2 spots with altered position and 2 proteins with both up-regulated abundance and altered position were also demonstrated. Moreover, the results exhibited 20 spots changed by Ang II and 7 spots changed by TGF-β1. 14 spots regulated by both Ang II and TGF-β1 were identified by mass spectrometry. Except for cytoskeleton proteins, it was first found that ubiquitin proteasome system and purine biosynthesis were required by differentiation of MF. Furthermore, decrease of septin 2 may be a marker in process of fibroblasts phenotypic transformation. Application of proteomic technique has displayed more novel proteins involved in MF differentiation, which provide new ideas and targets for investigating and intervening cell transformation.

Key words: adventitia, fibroblast, differentiation, angiotensin II, transforming growth factor-beta 1, two-dimensional electrophoresis, mass spectrometry