Translational Model Development: Rapamycin, Aging, and Endothelial Dysfunction

描述（由申请人提供）：我们的目标是开发一种安全的体内人类模型，该模型可以解释雷帕霉素（RAPA）延长小鼠寿命但仍导致内皮功能障碍的矛盾启示。我们的试点项目将通过使用局部、非侵入性和微创技术来开发这种新模型，以检查局部RAPA治疗在身体小区域的效果，避免全身给药的风险。 尽管有抗衰老作用，但据报道RAPA通过增加氧化和亚硝化应激引起内皮功能障碍，这是一种导致动脉粥样硬化和其他人类血管病变的有害过程。临床研究发现，RAPA洗脱支架可诱导内皮功能障碍，并增加人体支架内血栓形成风险。 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RAPA要作为一种抗衰老疗法安全地转化为临床医学，这种令人困惑的效果二分法必须得到解释。虽然RAPA似乎有抗衰老的好处，我们假设，有害的血管内皮细胞的影响限制了其在人类中的用途。我们将在开发和验证我们的局部治疗模型中解决的具体目标是定义：I.局部施用的软膏中RAPA的最佳浓度，其实现mTOR的可再现和功能相关的抑制（21，51）。II.用RAPA软膏局部治疗的mTOR抑制是否改变皮肤中的间质超氧化物、过氧化氢、生物可利用NO、NADPH氧化酶和内皮NOS水平（13，15，40）。III.通过监测局部RAPA软膏对局部皮肤变暖的血管反应的影响，RAPA对mTOR的抑制是否改变了内皮功能（28，32，47）。 目的将在健康人类受试者中进行。RAPA软膏将用于治疗一侧前臂的皮肤，软膏溶剂将用于治疗对侧前臂;因此，每例受试者将作为其自身对照。测量RAPA交付，超氧化物和H2 O2，生物可利用的NO，和内皮细胞对局部皮肤变暖的反应将比较RAPA治疗和车辆治疗的皮肤区域，以解决我们的目标。我们提出的模型将使我们能够安全地确定RAPA对人体血管功能的影响;这是将RAPA转化为人类抗衰老疗法的必要先决条件。

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.