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Background To fill the gap between acute and chronic stimulation methods of angiotensin II (Ang II) and obtain relevant signaling information, we have made an adenovirus vector encoding a furin-cleavable Ang II fusion protein. Methods Vascular smooth muscle cells (VSMCs) were infected with adenovirus to evaluate Ang II production. Also, expression of early growth response-1 (Egr-1) and hypertrophic responses were examined in VSMCs. Results Acute stimulation of VSMCs with synthetic Ang II showed the peptide had a half-life of less than 1 h. Infection of VSMCs with Ang II adenovirus showed a time-dependent production of Ang II as early as 2 days and up to 7 days postinfection. The Ang II adenovirus induced VSMC hypertrophy, stimulated Egr-1 expression, and suppressed Ang II type 1 receptor mRNA expression. Chronic Ang II infusion in mice for 2 weeks markedly enhanced Egr-1 immunostaining in carotid artery compared with the control saline infusion. Conclusion Application of the Ang II adenovirus vector to cultured cells will be useful to elucidate molecular and signaling mechanisms of cardiovascular diseases associated with enhanced Ang II production.

Background Health benefits of brown rice over white rice have been described previously. However, whether the outer bran of rice contains an ingredient useful to prevent cardiovascular diseases remains unknown. The subaleurone layer of rice, which is usually lost by milling brown rice for whitening, is rich in varied nutrients, suggesting that some ingredient contained within this layer may be beneficial for the cardiovascular system. Methods To assess potential benefits of the subaleurone layer toward pathological vascular remodeling, we examined the effects of the layer extracts from Japanese rice (Oryza sativa var. japonica) on angiotensin II (Ang II)-induced signal transduction and hypertrophy in cultured rat vascular smooth muscle cells (VSMCs). Results Pretreatment of the ethyl acetate extract (100 µg/ml), but not other extracts, inhibited Ang II (100 nmol/l)-induced immediate signal transduction events. Also, the extract diminished c-Fos expression and hypertrophic protein accumulation induced by Ang II in the cells. Conclusion These data suggest that an ingredient in the ethyl acetate extract from the subaleurone layer of rice has a protective effect toward cardiovascular diseases by interfering with signal transduction induced by Ang II.