Translational Model Development: Rapamycin, Aging, and Endothelial Dysfunction

描述(申请人提供)：我们的目标是开发一种安全的活体人类模型，能够解释雷帕霉素(RapA)延长小鼠寿命但仍会导致内皮功能障碍的相互矛盾的揭示。我们的试点项目将通过使用局部、非侵入性和微侵入性技术来开发这一新模型，以检查身体小区域局部RAPA治疗的效果，从而避免全身给药的风险。尽管有抗衰老的作用，但据报道，RAPA通过增加氧化和亚硝化应激导致内皮功能障碍，这是一个导致动脉粥样硬化和其他人类血管疾病的有害过程。临床研究发现，RAPA洗脱支架会导致血管内皮功能障碍，增加支架内血栓形成的风险。因此，RAPA似乎具有长期寻求的抗衰老作用，但可能具有有害的心血管作用。如果要将RAPA安全地转化为临床药物作为一种抗衰老疗法，这种令人困惑的效果二分法必须得到解释。尽管RAPA似乎有抗衰老的好处，但我们假设有害的血管内皮效应限制了它在人类中的用途。我们在开发和验证我们的局部治疗模型时将解决的具体目标是：i.局部应用的软膏中实现对mTOR(21，51)的可重复性和功能相关的抑制的最佳RAPA浓度。皮肤间质超氧化物歧化酶、过氧化氢、生物可利用的一氧化氮、NADPH氧化酶和内皮型一氧化氮合酶的水平是否因局部使用RAPA软膏(13、15、40)而被mTOR抑制而改变。RAPA抑制mTOR是否通过监测局部皮肤变暖对血管反应的影响来改变内皮功能(28，32，47)。AIMS将在健康的人类受试者中得到解决。RAPA软膏将用于治疗一侧前臂的皮肤，软膏载体将用于治疗对侧前臂；因此，每个受试者将由他/她自己控制。RAPA释放、超氧化物和过氧化氢水平、生物可利用的NO和内皮对局部皮肤变暖的反应的测量将在RAPA处理的皮肤区域和赋形剂处理的皮肤区域之间进行比较，以实现我们的目标。我们建议的模型将使我们能够安全地确定RAPA对人体体内血管功能的影响；这是将RAPA转化为人类抗衰老疗法的基本前提。

DESCRIPTION (provided by applicant): Our goal is develop a safe, in vivo human model that can translate the conflicting revelations that rapamycin (RAPA) expands lifespan in mice but yet causes endothelial dysfunction. Our pilot project will develop this new model by using local, non- invasive and minimally invasive techniques to examine the effects of local RAPA treatment in small areas of the body, obviating risks of systemic drug administration. Despite anti-aging effects, RAPA has been reported to cause endothelial dysfunction through increased oxidative and nitrosative stress, a deleterious process that leads to atherosclerosis and other human vasculopathies. Clinical studies find that RAPA eluting stents induce endothelial dysfunction and increase in-stent thrombosis risk in humans. RAPA thus appears to have long-sought anti-aging effects, but yet may have deleterious cardiovascular effects. This confusing dichotomy of effects must be explained if RAPA is to be translated safely into clinical medicine as an anti-aging therapy. Although RAPA appears to have anti-aging benefits, we hypothesize that deleterious vascular endothelium effects limits its usefulness in humans. Specific aims we will address in developing and validating our local treatment model are to define: I.the optimal concentration of RAPA in a topically applied ointment that achieves a reproducible and functionally relevant inhibition of mTOR (21, 51). II.whether interstitial superoxide, hydrogen peroxide, bioavailable NO, NADPH oxidase, and endothelial NOS levels in skin are altered by mTOR inhibition with topical treatment with RAPA ointment (13, 15, 40). III.whether mTOR inhibition by RAPA alters endothelial function by monitoring the effects of topical RAPA ointment on vascular responses to local skin warming (28, 32, 47). Aims will be addressed in healthy human subjects. RAPA ointment will be used to treat skin of one forearm and ointment vehicle will be used to treat the contralateral forearm; thus each subject will be his/her own control. Measurements of RAPA delivery, levels of superoxide and H2O2, bioavailable NO, and endothelial responses to local skin warming will be compared between RAPA-treated and vehicle-treated skin regions to address our aims. Our proposed model will allow us to safely determine the effects of RAPA on vascular function in humans in vivo; an essential prerequisite for translating RAPA into an anti-aging therapy for humans.