Rapamycin / mTOR inhibition

The mechanistic target of mTOR(definition)-inhibiting drug studied for extending healthspan and lifespan." style="text-decoration:underline dotted; text-underline-offset:2px; cursor:help;">rapamycin(definition) (mTOR) is a conserved checkpoint kinase and a central component of the PI3K/AKT/mTOR signaling network that governs cell growth, protein synthesis, survival, and cell cycle progression [2, 4]. Dysregulation of this pathway is implicated in cancer and tumor malignancies [4, 5, 7]. Consensus demonstrates that pharmacological inhibition of mTOR using rapamycin extends lifespan in model organisms, including yeast, flies, and genetically heterogeneous mice—even when administered late in life [3, 8]. Furthermore, rapamycin targets metabolic dysregulation to attenuate age-related pathologies such as atrial remodeling and fibrillation [9].

Despite its lifespan-extending benefits, chronic mTOR(definition)-inhibiting drug studied for extending healthspan and lifespan." style="text-decoration:underline dotted; text-underline-offset:2px; cursor:help;">rapamycin(definition) administration paradoxically impairs glucose tolerance and induces insulin resistance [8]. Mechanistically, this adverse metabolic effect is driven by the disruption and loss of mTORC2, demonstrating that the metabolic side effects can be uncoupled from longevity benefits [8]. Other open questions remain regarding the precise cross-interactions within upstream and downstream signaling nodes [2, 4] and fully characterizing the complex tissue-specific trade-offs of chronic mTOR inhibition.

The strength of evidence supporting mTOR(definition)'s role in growth regulation and rapamycin(definition)-induced lifespan extension across diverse model organisms is robust and well-replicated [2, 3, 8]. Evidence regarding the specific bifurcation between mTORC1-mediated longevity and mTORC2 loss-induced insulin resistance is supported by targeted experimental findings [8], while emerging studies continue to map out its translational potential in age-related tissue remodeling [9].