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L'aumento di ABCA1 determina un aumento di HDL

L'inibizione della degradazione proteolitica di ABCA1 (ATP-binding cassette transporter) comporta un aumento della biogenesi delle HDL. Il risultato finale dell'aumento dell'attività di ABCA1 è l'accelerazione del trasporto inverso del colesterolo con potenzialità di prevenzione dell'aterosclerosi.

Pharmacological inhibition of ABCA1 degradation increases HDL biogenesis and exhibits antiatherogenesis

Arakawa R, Tsujita M, Iwamoto N, Ito-Ohsumi C, Lu R, Wu CA, Shimizu K, Aotsuka T, Kanazawa H, Abe-Dohmae S, Yokoyama S.

J Lipid Res 2009;50:2299-2305

Expression of ABCA1 is regulated by transcription of the gene and calpain-mediated proteolytic degradation, and inhibition ABCA1 degradation results in increased ABCA1 and HDL biogenesis in vitro. We examined whether this approach could be a potential antiatherogenic treatment. Although probucol inhibits both the activity and degradation of ABCA1, its oxidized products, spiroquinone and diphenoquinone, reduce degradation of ABCA1 without inhibiting its activity or altering transcription of the ABCA1 gene. Accordingly, both compounds enhanced apolipoprotein A-I/ABCA1-dependent generation of HDL in vitro, and increased hepatic ABCA1 and plasma HDL without increasing antioxidant activity in plasma when given to rabbits. Both compounds also decreased vascular lipid deposition in cholesterol-fed rabbits. We therefore conclude that stabilization of ABCA1 against calpain-mediated degradation is a novel and potentially important strategy to increase HDL formation and prevent atherosclerosis. Spiroquinone and diphenoquinone are potential seeds for development of such drugs.

J Lipid Res 2009;50:2299-2305