Response to the Thought-Provoking Critique of Hyperfunction Theory by Aubrey de Grey

Mikhail 'Misha' Blagosklonny's enduring legacy in geroscience: the hyperfunction theory and the therapeutic potential of rapamycin

The untimely passing of Dr. Mikhail "Misha" Blagosklonny has left a lasting void in geroscience and oncology. This review examines his profound contributions, focusing on his pioneering the Hyperfunction Theory and his advocacy for rapamycin, an mTOR inhibitor, as a therapeutic agent for lifespan extension. Contrary to traditional damage-centric models, the Hyperfunction Theory rejects damage accumulation as the primary driver of aging. Instead, it redefines aging as a quasi-programmed process driven by the persistent, excessive activity of growth-promoting pathways beyond their developmental roles, leading to age-related pathologies. We explore how Blagosklonny's insights predict rapamycin's ability to decelerate aging by modulating excessive mTOR signaling, supported by empirical evidence across multiple physiological systems, including immune, cardiovascular, cognitive, and oncologic health. His forward-thinking approach, advocating for the cautious clinical use of rapamycin and suggesting personalized, preventive, and combination therapy strategies, has catalyzed interest in translational geroscience. This review synthesizes Blagosklonny's legacy, presenting rapamycin as a foundational pharmacological intervention with potential in managing age-related decline and extending healthspan, and underlines his impact in shifting aging research from theoretical frameworks to actionable interventions. Blagosklonny's work remains an enduring inspiration, paving the way toward treating aging as a modifiable condition.

Consolidating multiple evolutionary theories of ageing suggests a need for new approaches to study genetic contributions to ageing decline

Understanding mechanisms of ageing remains a complex challenge for biogerontologists, but recent adaptations of evolutionary ageing theories offer a compelling lens in which to view both age-related molecular and physiological deterioration. Ageing is commonly associated with progressive declines in biochemical and molecular processes resulting from damage accumulation, yet the role of continued developmental gene activation is less appreciated. Natural selection pressures are at their highest in youthful periods to modify gene expression towards maximising reproductive capacity. After sexual maturation, selective pressure diminishes, subjecting individuals to maladaptive pleiotropic gene functions that were once beneficial for developmental growth but become pathogenic later in life. Due to this selective 'shadowing' in ageing, mechanisms to counter such hyper/hypofunctional genes are unlikely to evolve. Interventions aimed at targeting gene hyper/hypofunction during ageing might, therefore, represent an attractive therapeutic strategy. The nematode Caenorhabditis elegans offers a strong model for post-reproductive mechanistic and therapeutic investigations, yet studies examining the mechanisms of, and countermeasures against, ageing decline largely intervene from larval stages onwards. Importantly, however, lifespan extending conditions frequently impair early-life fitness and fail to correspondingly increase healthspan. Here, we consolidate multiple evolutionary theories of ageing and discuss data supporting hyper/hypofunctional changes at a global molecular and functional level in C. elegans, and how classical lifespan-extension mutations alter these dynamics. The relevance of such mutant models for exploring mechanisms of ageing are discussed, highlighting that post-reproductive gene optimisation represents a more translatable approach for C. elegans research that is not constrained by evolutionary trade-offs. Where some genetic mutations in C. elegans that promote late-life health map accordingly with healthy ageing in humans, other widely used genetic mutations that extend worm lifespan are associated with life-limiting pathologies in people. Lifespan has also become the gold standard for quantifying 'ageing', but we argue that gerospan compression (i.e., 'healthier' ageing) is an appropriate goal for anti-ageing research, the mechanisms of which appear distinct from those regulating lifespan alone. There is, therefore, an evident need to re-evaluate experimental approaches to study the role of hyper/hypofunctional genes in ageing in C. elegans.

Aging is a Side Effect of the Ontogenesis Program of Multicellular Organisms

The review presents a brief outline of the current state of the main theoretical approaches to the aging problem. The works of authors, supporting the theory of "accumulation of errors" and theories stating the presence of a hypothetical "aging program" in all multicellular organisms are reviewed. The role of apoptosis and its connection with phenoptosis, as well as the theory of "hyperfunction" are analyzed. Our own approach to this problem is presented, in which aging is explained by the redistribution of limited resources between the two main aims of the organism: its self-sufficiency, based on the function of the housekeeping genes (HG) group, and functional specialization, provided by the integrative genes (IntG) group. Agreeing with the inseparable connection between aging and the ontogenesis program, the main role in the aging mechanisms is assigned to the redistribution of resources from the HG self-sufficiency genes to the IntGs necessary for the operation of all specialized functions of the organism as a whole. The growing imbalance between HGs and IntGs with age, suggests that switching of cellular resources in favor of IntGs is a side effect of ontogenesis program implementation and the main reason for aging, inherent in the nature of genome functioning under conditions of highly integrated multicellularity. The hypothesis of functional subdivision of the genome also points to the leading role of slow-dividing and postmitotic cells, as the most sensitive to reduction of repair levels, for triggering and realization of the aging process.

Rapamycin treatment early in life reprograms aging: hyperfunction theory and clinical practice

Making provocative headlines, three outstanding publications demonstrated that early-life treatment with rapamycin, including treatments during developmental growth, extends lifespan in animals, confirming predictions of hyperfunction theory, which views aging as a quasi-program (an unintended continuation of developmental growth) driven in part by mTOR. Despite their high theoretical importance, clinical applications of two of these studies in mice, Drosophila and Daphnia cannot be implemented in humans because that would require growth retardation started at birth. A third study demonstrated that a transient (around 20% of total lifespan in Drosophila) treatment with rapamycin early in Drosophila adult life is as effective as lifelong treatment, whereas a late-life treatment is not effective. However, previous studies in mice demonstrated that a transient late-life treatment is highly effective. Based on hyperfunction theory, this article attempts to reconcile conflicting results and suggests the optimal treatment strategy to extend human lifespan.

Hallmarks of cancer and hallmarks of aging

A thought-provoking article by Gems and de Magalhães suggests that canonic hallmarks of aging are superficial imitations of hallmarks of cancer. I took their work a step further and proposed hallmarks of aging based on a hierarchical principle and the hyperfunction theory.

To do this, I first reexamine the hallmarks of cancer proposed by Hanahan and Weinberg in 2000. Although six hallmarks of cancer are genuine, they are not hierarchically arranged, i.e., molecular, intra-cellular, cellular, tissue, organismal and extra-organismal. (For example, invasion and angiogenesis are manifestations of molecular alterations on the tissue level; metastasis on the organismal level, whereas cell immortality is observed outside the host).

The same hierarchical approach is applicable to aging. Unlike cancer, however, aging is not a molecular disease. The lowest level of its origin is normal intracellular signaling pathways such as mTOR that drive developmental growth and, later in life, become hyperfunctional, causing age-related diseases, whose sum is aging. The key hallmark of organismal aging, from worms to humans, are age-related diseases. In addition, hallmarks of aging can be arranged as a timeline, wherein initial hyperfunction is followed by dysfunction, organ damage and functional decline.