EDitoriaLs: CELL CyCLE FEaturEs 4298 Cell Cycle Volume 11 issue 23

While rapamycin was discovered as a fungicide in 1975, it is now famous for its ability to suppresses mammalian cell aging1,2 and to extend lifespan in mice.3,4 Rapamycin is an oral immunomodula-tory agent approved to prevent rejection in human organ transplantation. It also exerts an antitumor activity as well as an anti-restenosis activity, when used in drug-eluting stents. In addition, rapamycin has neuroprotective effects in traumatic brain injury models, with increased neuron survival and recovery of brain functions. Nevertheless, there has been a practical limitation in performing physiologic stud-ies with rapamycin, because rapamycin has very poor water solubility and bio-availability.5 To maximize the research and clinical application of rapamycin, it is advantageous to dissolve rapamycin in a physiologic and isotonic solution. To overcome this limitation (poor water solubility), we solubilized rapamycin in isotonic buffer using reconstituted high-density lipoprotein containing V156K-apoA-I (V156K-rHDL).6 Apolipoprotein (apo) A-I is a principal protein component of HDL and is known to perform a ben-eficial role in the reverse cholesterol trans-port pathway through its antioxidant and antiinflammatory activities. HDL have atheroprotective effects with potent anti-oxidant, antiinflammatory, anti-diabetic activities. Recently, we showed that rHDL containing V156K-apoA-I, had a potent antioxidant activity and was more resis-tant to glycation, with more enhanced tissue regeneration activity as a HDL-therapy. More resistance to glycation is advantageous to develop a protein-based drug for both anti-atherosclerotic and anti-diabetic agents. These results suggest Rapamycin in lipoproteins for enhanced deliver