Enhanced delivery of rapamycin by V156K-apoA-I high-density lipoprotein inhibits cellular proatherogenic effects and senescence and promotes tissue regeneration

Although rapamycin (rapa) is a fungicide, it is now believed to possess the capacity to extend mammalian life span. Because rapamycin is insoluble in water, its study in the aqueous phase has been limited. We therefore solubilized rapamycin in isotonic buffer using reconstituted high-density lipoprotein containing V156K-apolipoprotein A-I (V156K-rHDL). Rapamycin (final concentration, 0.1 mg/mL) was solubilized in rHDL containing either wild-type (WT) or V156K-apoA-I (1 mg/mL of protein) prepared using the sodium cholate dialysis method. V156K-rHDL containing rapamycin (V156K-rapa-rHDL) had a slightly larger particle size than rapamycin-loaded WT-rHDL (WT-rapa-rHDL). V156K-rapa-rHDL exhibited enhanced antioxidant ability, cholesteryl ester transfer protein inhibitory activity, and anti-atherosclerotic activity. Treatment with V156K-rapa-rHDL resulted in attenuation of senescence in human cells with increased cell survival and enhancement of tissue regenerative activities in zebrafish model compared with WT-rapa-rHDL or rHDL alone.