Conditional expression of anti-apoptotic protein p35 by Cre-mediated DNA recombination in cardiomyocytes from IoxP-p35-transgenic mice

p35, a viral inhibitor of caspase, prevents cell death induced by various s timuli. We established an experimental system to study the involvement of c aspases in cell death, using primary cultured cells from p35 transgenic mic e in which the p35 open reading frame (ORF) had been disrupted by the inser tion of a DMA segment flanked by loxP sites, the Ore recognition sites. In this system, p35 expression can be initiated by Ore recombinase, Cardiomyoc ytes, which are highly sensitive to hypoxic stress, were infected with an a denovirus carrying the cre gene (AxCANCre), Expression of p35 by infection with AxCANCre resulted in inhibition of caspase-3 activation and resistance to hypoxia-induced cell death. Hypoxia-induced cytochrome c release was al so attenuated in p35-expressing cardiomyocytes, Our transgenic mice can be used as an experimental model for studying the involvement of caspases in v arious degenerative diseases as well as programmed cell death both in vitro and in vivo.