Fight Aging!

An archly conservative viewpoint links establishment academia ("this thing you are doing has not yet been proven beyond all doubt to work") to the thought leadership of Big Pharma ("this thing you are doing has not yet been proven beyond all doubt to generate profit"). Both sides look at the billions in funding devoted to the growing longevity industry, and the decades of painstaking scientific work that set the foundation for that industry, and see an ongoing test in progress, as yet unfinished and the result undetermined. Can aging in fact be slowed or reversed in a practical way in humans as it can in laboratory species?

There are those who determinedly take a wait and see approach, wanting the concrete answer. Obviously a great many other people, scientists, entrepreneurs, patients, and patient advocates, are less conservative than this, otherwise there would be no longevity industry. Many lines of work that lead to potential rejuvenation therapies are highly promising, and the only remaining question is how much additional life they can provide to members of our own species. The future is ever uncertain, but one doesn't win victories by refraining from participation.

Today's open access review, being a very broad survey of everything that might fall into the purview of the diverse longevity industry, lumps together a range of very different approaches under one heading. I think this a mistake, a category error that is becoming common. At the very least one should not be placing NAD+ upregulation (unreliable animal data, small effect size, long history of failed human trials for a range of conditions) into equivalence to senolytics to clear senescent cells (reliable and extensive animal data, large effect size for reversal of age-related conditions, mixed data from only a few early human trials). These are very different classes of therapy with very different supporting evidence, and emerge from very different philosophies of development.

Geroprotective Effects of Drugs Modulating Metabolic Pathways: Perspectives of Pharmacology in Anti-Aging Therapy

Aging is the strongest risk factor for chronic diseases such as cardiovascular diseases, cancer, diabetes, and neurodegenerative disorders. Advances in geroscience indicate that pharmacological modulation of conserved molecular pathways may extend healthspan and delay multimorbidity. This review focused on molecular pathways implicated in aging, pharmacological interventions targeting these pathways, and their preclinical and clinical evaluation. Particular emphasis was placed on translational evidence, including human biomarker studies and randomized clinical trials, and on the distinction between biomarker modulation and clinically meaningful outcomes.

Repurposed drugs such as metformin and rapamycin have among the most extensive preclinical and translational evidence, although clinical evidence for broadly applicable geroprotection remains limited. Statins, SGLT2 inhibitors, GLP-1 receptor agonists, and menopausal hormone therapy have established disease-specific or cardiometabolic benefits that may have indirect relevance to geroprotection, but direct effects on biological aging and healthspan remain unproven. Other candidates, including senolytics, NAD+ precursors, taurine, and epigenetic reprogramming approaches, are at different stages of translational development, with evidence ranging from promising preclinical findings to early human studies.

Across interventions, a substantial gap remains between mechanistic plausibility and clinically validated geroprotection. Geroprotective pharmacology represents a promising but incompletely validated approach to extending healthspan. Major uncertainties include the absence of universally accepted biomarkers and clinical endpoints of biological aging, heterogeneity in treatment response, optimal timing and duration of interventions, and long-term safety. Future research should prioritize adequately powered randomized clinical trials integrating standardized measures of biological aging with clinically meaningful outcomes, alongside biomarker-guided patient selection, appropriate treatment timing, and careful assessment of long-term safety.

Mitochondrial transplantation as a form of therapy to improve mitochondrial function in aged tissues has barely started as a going concern, and only a few patients have been treated in early studies conducted to date. Yet once the protocols for manufacture and quality control become widely known, availability will likely spread quickly through the medical tourism community, made up of clinics with staff already experienced in the similar techniques used in the provision of stem cell therapies and exosome therapies. Certainly, the research community has already moved on to debating how to improve delivery of mitochondria via a range of potential approaches, and that there will soon enough be an industry hungry for such improvements is assumed to be the case.

Despite the central role of mitochondrial dysfunction in disease progression, current therapeutic strategies remain largely indirect and insufficient for restoring damaged mitochondrial networks. Mitochondrial transplantation introduces a conceptually distinct approach by directly supplying healthy mitochondria to injured cells, shifting mitochondrial medicine from molecular modulation toward organelle replacement and laying the foundation for organelle-level therapy. The concept of mitochondrial transplantation is supported not only by therapeutic need but also by the natural biology of intercellular mitochondrial transfer. Early studies demonstrated that mitochondria or mitochondrial DNA can move between mammalian cells and rescue aerobic respiration in cells with nonfunctional mitochondria.

However, endogenous mitochondrial transfer is spatially restricted, context-dependent, and difficult to control therapeutically. Therefore, the clinical translation of mitochondrial transplantation requires engineered systems that can reproduce the protective and selective features of natural transfer while enabling scalable, stable, and targetable delivery. Early mitochondrial transplantation studies largely relied on the direct administration of isolated free mitochondria; however, this approach was limited by the rapid loss of mitochondrial activity in the extracellular environment, immune-mediated clearance, and inefficient delivery to target tissues. Free mitochondria are intrinsically fragile once removed from the intracellular environment. During isolation, storage, circulation, and uptake, mitochondria are exposed to mechanical stress, osmotic fluctuation, calcium overload, oxidative damage, and extracellular stress, all of which can compromise membrane potential and respiratory competence.

To overcome the limitations of free mitochondrial administration, engineered delivery has become a central determinant of mitochondrial transplantation efficacy. Collectively, recent advances have shifted mitochondrial transplantation from the simple administration of isolated organelles toward carrier-assisted and target-oriented delivery systems. These strategies can be broadly categorized into surface-engineered mitochondria, cell-mediated mitochondrial transport, vesicle-encapsulated mitochondrial delivery, and cell-type-targeted mitochondrial transplantation.

Link: https://doi.org/10.1016/j.scib.2026.08.058

It is well known that electromagnetic fields affect cellular biochemistry, but the interactions are complex enough that electromagnetic therapies have yet to emerge in any robust way. It remains challenging to replicate and explain benefits arising in some studies from even long-standing forms of electromagnetic therapy, such as the use of pulsed electromagnetic field devices. While in principle carefully sculpted electromagnetic fields can enhance or impede specific biochemical reactions occurring in cells, in practice this line of development remains largely unexplored. Here, by shielding flies with and without mutations affecting mitochondrial function from the natural geomagnetic field, reducing field strength to a very low level, researchers show that the geomagnetic field meaningfully affects mitochondrial function, and thus longevity. The effects are clearly complex and circumstantial, however, far from straightforward.

Modulation of magnetic field strength may be a potential therapeutic strategy, particularly in the context of ageing and neurodegenerative disease. Research on magnetic fields (MFs) has been motivated by diverse factors, including interplanetary space travel, emissions from medical equipment, and the mechanisms underlying magnetoreception in migratory birds. The biochemistry of hypomagnetic field (HMFs; <5 μT) exposure has focused on healthy model organisms, leaving their therapeutic potential unexplored.

We investigated the effects of HMF exposure in a neurodegenerative disease model. The Pink1 loss-of-function model recapitulates key features of early-onset Parkinson's disease, including mitochondrial dysfunction, locomotor impairment, dopaminergic neuron degeneration, and reduced lifespan. A benchtop shielding apparatus was used to generate a uniform internal field of 5 nT, to effectively remove Earth's geomagnetic field (GMF; 25-60 μT). Wild-type (WT) and Pink1 knockout D. melanogaster were exposed to HMF and assessed for survival, locomotor performance, mitochondrial respirometry and reactive oxygen species production.

HMF exposure increased lifespan in Pink1⁻ D. melanogaster by 20%, with a paradoxical reduction in climbing ability. WT D. melanogaster had decreased lifespan and improved locomotor performance under HMF. Nitrogen-vacancy (NV) centre quantum diamond sensors, were used to detect elevated superoxide levels following HMF exposure. High-resolution respirometry showed increased mitochondrial complex II activity under HMF conditions. In conclusion, hypomagnetic fields modulate mitochondrial physiology and reactive oxygen species production in D. melanogaster. This highlights the potential of HMF exposure as a novel, non-invasive approach for modulating mitochondrial dysfunction in neurodegenerative disease.

Link: https://doi.org/10.18632/aging.206424

Of the many varied approaches to mimic some of the beneficial metabolic response to calorie restriction, mTOR inhibition is arguably the most well studied. Countless animal studies have been conducted, and early clinical trials for novel mTOR inhibitors have taken place. The mTOR inhibitor rapamycin is a generic, low cost drug now used by a growing number of people for its potential to slow aging. That potential remains to be proven in humans, but in mice rapamycin produces a reliable 10% to 20% increase in life span. Like calorie restriction, mTOR inhibitors appear to produce their benefits as a consequence of the increased operation or efficiency of autophagy, a collection of maintenance processes that recycle damaged proteins and structures in the cell. Near all forms of stress response converge on autophagy, which acts to improve cell function and resilience.

Today's open access review is a short deep dive into the biochemistry of mTOR, the role of mTOR in aging, and ability of mTOR inhibitors to modestly slow aging. If there is a single point that the authors would like you to take away with you, it is that mTOR is not a straightforward target. Optimal mTOR inhibition is context and tissue dependent, and there is probably room to improve on the sort of pharmacological mTOR inhibition conducted to date via rapamycin and similar small molecule drugs. Nonetheless, there is still a compelling argument to be made that rapamcyin is a cost-effective treatment for aging, blunt as it is, and modest as the effects are. A small benefit for a trivial cost is still a win. That argument still needs to be resolved with human data, however, and movement towards that goal is painfully slow. Low cost drugs have few champions willing to underwrite the huge expense of formal human trials.

mTOR signaling in aging: from causality to geroprotective interventions and hallmark-level outcomes

Protein kinases are tightly regulated enzymes that ensure signaling fidelity through precise spatial and temporal control of their activity. Protein kinases constitute one of the largest and most functionally important enzyme families. They regulate virtually all major biological processes by transferring phosphate groups from adenosine triphosphate (ATP) to serine, threonine, or tyrosine residues. This reversible post-translational modification propagates intracellular signaling through phosphorylation cascades, whereas phosphatases terminate signaling by removing phosphate groups from target proteins.

Among phosphatidylinositol 3-kinase-related kinases (PIKKs), mechanistic target of rapamycin (mTOR) occupies a central position in aging biology owing to its role in coordinating nutrient sensing, metabolism, and stress adaptation. mTOR is a multidomain serine/threonine kinase that integrates environmental and intracellular signals to regulate metabolism, growth, autophagy, and cell survival. It assembles into two functionally distinct complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2), which differ in molecular composition, upstream regulation, and downstream signaling outputs.

Rather than functioning as a linear signaling pathway, mTOR acts as a dynamic signaling hub that coordinates anabolic and catabolic processes in response to nutrient availability, energy status, and cellular stress. Dysregulated or persistent mTOR activation is associated with reduced metabolic flexibility, impaired stress adaptation, and accelerated aging, whereas context-dependent modulation of mTORC1 and mTORC2 supports cellular homeostasis and organismal resilience. Consequently, mTOR has become one of the principal molecular targets in geroscience and a promising focus for interventions aimed at promoting healthy aging.

This review provides an integrative analysis of the molecular architecture and biological functions of mTOR signaling, with particular emphasis on the emerging role of mTORC2 in aging and longevity. It examines mechanistic, genetic, experimental, and translational evidence linking mTOR signaling to lifespan regulation and critically evaluates current geroprotective interventions that modulate this pathway. Finally, the review discusses the therapeutic opportunities, biological trade-offs, and remaining translational challenges of targeting mTOR signaling to improve healthspan and healthy aging.

Later stages of Alzheimer's disease and other tauopathies are characterized by the aggregation of altered tau protein, and a toxic surrounding biochemistry that provokes inflammation and destroys neurons. So far little headway has been made towards therapies that can halt tau pathology, by clearing harmful tau or preventing its formation. Given the several decade span of intense effort devoted to the clearance of amyloid-β in the brain before success ultimately emerged, we might expect that much more remains to be accomplished in order to reach the same point for tau. Unfortunately, many discoveries in the neurodegenerative field are approaches that cannot be curative, and this is the case here. The peptide discussed can only reduce tau pathology in mouse models of tauopathy, not eliminate it.

Neurodegenerative disorders such as Alzheimer's disease (AD), Corticobasal Degeneration (CBD), and Progressive Supranuclear Palsy (PSP) are characterized by tau aggregation, neuroinflammation, and progressive cognitive decline. Although metabolic dysregulation and neuropeptide imbalance have been linked to these disorders, the functional consequences of this imbalance and its reversal remain poorly understood. Our previous work identified chromogranin A (CgA), the gene encoding a pro-hormone for several metabolic peptides, as a key regulator of tau pathology.

Here, we investigate Catestatin (CST), a CgA-derived peptide, for its role in modulating tauopathy. We report marked reductions in CST levels and an increase in Pancreastatin (PST) in the hippocampus and cortex of AD brains, as well as in the frontal cortex of CBD and the basal ganglia of PSP. CST-supplementation in cortical neuronal cultures and organotypic slice cultures (OTSC) reduced Tau phosphorylation and aggregation. In vivo, CST administration to PS19 tauopathy mice decreased pathological Tau species, attenuated gliosis, improved cognitive function, and reduced amyloid burden and neuroinflammation in 5xFAD mice.

Mechanistically, CST reduced epinephrine levels in PS19 and 5xFAD mice, suppressed Protein Kinase A hyperactivation in PS19 and OTSC, and revealed a link between CST deficiency, adrenergic stress signaling, tauopathy-mediated neurodegeneration, and the therapeutic potential of CST supplement.

Link: https://doi.org/10.1016/j.ymthe.2026.09.022

Researchers here provide an initial proof of concept demonstration of a novel foundation for replacing lost visual capacity in cases of retinal degeneration, without addressing the underlying pathology that causes loss of function in photoreceptor cells. Recall that direct stimulation of retinal cells by grid electrodes implanted in the retina has been used to produces a poor substitute for actual vision, but a substitute that allows blind people at least some capacity to navigate and even read. Here, researchers introduce light sensitive nanoparticles into the retina that can in principle provide the basis for a more refined artificial substitute for normal vision. Based on the results of the electrode grids, one would expect the result to be a view of the world painted in glowing shades of phosphenes at various intensities.

The possibility to electrically stimulate living tissue creates new opportunities for therapeutic applications. Interfaces between biology and nanomaterials open an array of possibilities for non-genetic modulation of bioelectric activity with subcellular spatiotemporal control. Nanoparticles (NPs) have shown to be able to build tight interfaces with both intra- and extracellular membranes. Importantly, light can trigger electrochemical or photothermal effects at the semiconductor NP/cellular interface acting as a leadless electrophysiological modulator.

Here, drawing inspiration from photosynthesis, we develop hollow-sphere graphitic carbon nitride nanoparticles (hg-C3N4 NPs) that can modulate biological activity from subcellular processes to whole-tissue function. The homogeneous hg-C3N4 NPs show responsiveness to light via both photoelectrochemical and photothermal mechanisms and can be spontaneously internalized with excellent cytocompatibility.

We demonstrate that hg-C3N4 nanoparticles can be safely delivered and elicit measurable cortical and behavioural light responses in a model of advanced retinal degeneration. The application of hg-C3N4 NPs to porcine retinal tissue ex vivo confirms their modulation capability to directly activate retinal ganglion cell activity under light-emitting diode photostimulation.

Link: https://doi.org/10.1038/s41551-026-01773-w

PD-L1 found on the surface of cells is a well known immune checkpoint protein. When it binds to the receptor PD-1 found on the surface of T cells and B cells, it acts to suppress immune activity. This is a necessary brake to avoid runaway immune reactions, but because it is also abused by cancer cells to shield them from the immune system, the cancer research community has given a great deal of attention to this and other forms of immune checkpoint. Checkpoint inhibitors such as antibodies for PD-L1 are a well established class of drug intended to enable the immune system to better attack cancerous cells.

In today's open access paper, researchers report on the results of delivering a PD-L1 antibody directly into the brains of Alzheimer's disease model mice. Past research has suggested that the more usual intravenous delivery outside the brain can help improve clearance of protein aggregates in the brain by immune cells, but the mechanism would have to be fairly indirect. The immune systems of body and brain are quite distinct from one another, separated by the blood-brain barrier, and in normal circumstances only small numbers of immune cells from the body can enter the brain. Would a more direct targeting of brain cells produce a larger effect?

While the authors of today's paper view checkpoint inhibition in terms of enabling greater clearance of protein aggregates by a more active population of immune cells, it seems plausible that clearance of senescent cells in the brain is equally important. Like cancerous cells, senescent cells in aged tissues have been found to employ immune checkpoint activation to preserve themselves from clearance by the immune system. Senescent cells are clearly detrimental to the aging brain, a major contribution to disruptive chronic inflammation. It is plausible that checkpoint inhibition could reduce the burden of senescent cells in an aging brain. Alas, the researchers here restrict themselves to measuring only some functional aspects of brain cell populations, so whether or not this is the case in the present study is unclear.

Targeting glial PD-1/PD-L1 restores microglial homeostasis and reduces neuronal hyperactivity in an Alzheimer's disease model

Immunotherapy targeting the immune checkpoint pathway, particularly the programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) axis, has emerged as a promising strategy for treating Alzheimer's disease (AD). Previous studies have suggested that the systemic administration of anti-PD-L1 antibody reduces amyloid-β burden and improves cognitive outcomes in AD mouse models, primarily by activating peripheral immune responses and promoting the recruitment of monocyte-derived macrophages (MDMs) into the brain. However, these studies have primarily focused on peripheral immune cells.

Unlike the systemic approaches, our study emphasizes the direct modulation of PD-1/PD-L1 signaling within the brain and its implications for glial and neuronal functions. Microglia, the brain's intrinsic immune cells, are central to maintaining neuronal homeostasis; they monitor neuronal activities and modulate synaptic functions. In AD, microglia often exhibit a dysfunctional state characterized by impaired phagocytosis, reduced motility, and altered gene expression. Astrocytes also play a vital role in maintaining brain homeostasis by modulating neuronal activities, thereby regulating synaptic transmission and supporting microglial function. PD-L1 expressed on astrocytes has been implicated in neuroimmune interactions, but its specific role in AD has not been fully investigated.

Increased PD-1 and PD-L1 levels in microglia and astrocytes show features analogous to their sustained expression in exhausted peripheral immune cells during chronic infections and tumors, in which they help suppress heightened immune responses. In AD, such upregulation of PD-1/PD-L1 may contribute to glial dysfunction, with potential consequences for immune surveillance and neuronal modulation. Consequently, targeting glial PD-1/PD-L1 signaling directly within the brain could provide a promising strategy to restore glial and neuronal function.

In this study, we investigated the effects of direct intracortical anti-PD-L1 administration on microglial function, neuronal activity, and amyloid-β pathology in a 5xFAD mouse model using real-time in vivo two-photon microscopy. Seven days after the intracortical injection, the anti-PD-L1 treatment effectively rescued microglial process motility and restored spontaneous neuronal calcium activity, while reducing amyloid-β plaque burden and increasing plaque-associated microglia. Furthermore, astrocyte-specific PD-L1 knockdown showed effects similar to those resulting from the inhibition of the glial PD-1/PD-L1 pathway. Collectively, our findings suggest that brain-intrinsic glial PD-1/PD-L1 modulation reduces amyloid-β pathology along with restoring functional interactions among microglia, astrocytes, and neurons.

Researchers here provide a proof of concept for the use of Raman spectroscopy to non-invasively measure the burden of senescent cells in an imaged tissue. This works because Raman imaging can provide distinct signatures of different molecules via scattering of photons. Provided the field of imaging is sufficiently constrained, it is possible to produce results that measure differing abundances of specific molecules in different cells. Senescent cells exhibit a range of upregulated and downregulated proteins and other molecules, so in principle creating a system to assess the presence of senescent cells is just a matter of putting in the work to construct and validate a specific implementation.

Aging and tissue repair involve heterogeneous remodeling across transcriptional, biochemical, and cellular dimensions, yet prevailing definitions rely on isolated molecular markers that obscure how these states co-evolve. Here we present RamanOmics, a multimodal framework integrating label-free hyperspectral Raman imaging with single-nucleus RNA sequencing and spatial transcriptomics to link biochemical states with transcriptional programs at single-cell spatial resolution.

Applied to young and old mouse lung and skin, RamanOmics reveals tissue-specific programs: lung senescent cells are enriched for extracellular matrix remodeling and transforming growth factor-β signaling, whereas skin senescence is dominated by epidermal differentiation genes (Krt10, Lor, and Sbsn). Across tissues, we identified a conserved lipid-linked Raman signature marking p21+ senescent cells and developed a machine learning-derived, multimodal barcode enabling nondestructive senescence identification in situ. In a mouse wound-healing model, RamanOmics reveals reactivation of epidermal differentiation genes (Krt10, Lor and Sbsn) in senescent cells, alongside increased lipid-associated Raman signatures.

Taken together, RamanOmics provides a tissue-agnostic framework for scalable, multimodal profiling of cellular states.

Link: https://doi.org/10.1038/s43587-026-01219-7

One of the more interesting new concepts in aging research is that repeated activation of the DNA damage response may cause epigenetic changes in the management of nuclear DNA structure that are characteristic of aging. It neatly explains how stochastic DNA damage to unused DNA sequences can possible contribute to aging. It also frames partial epigenetic reprogramming as a true rejuvenation therapy, one of the reasons why there is a great deal of funding for that line of work. Is it actually the case, however? The mechanistic evidence to date is suggestive, but as usual the question is less whether the mechanism exists and more whether it provides a meaningful contribution to degenerative aging. Maybe those epigenetic changes are largely the result of other processes, for example. Here, a researcher discusses the evidence to date, and proposes tests that one might consider running in order to provide a better set of answers regarding the contribution of the DNA damage response to aging than presently exist.

Aging is multi-causal, yet its molecular hallmarks may converge on a few upstream integrating nodes. We advance the hypothesis that chronic, largely mutation-independent overactivation of the DNA damage response (DDR) is one such node, dysregulating the cell's intact guardian pathways - the tumor-suppressor networks and their negative regulators - to induce senescence, deplete stem-cell pools, and drive inflammaging. Unlike cancer, where mutations inactivate these guardians, aging more often reflects functional dysregulation of wild-type pathways, either chronically overactivated (p53, p16INK4a) or epigenetically silenced (SIRT1, FOXO3, NRF2, Klotho). That the very programs guarding against cancer can, when chronically engaged, come to drive aging we term the guardian paradox.

We organize 16 candidate axes - which we term the aging axis - across three evidence tiers, mapped onto the hallmarks of aging, outlining for each a conceptual diagnostic signature and an illustrative restoration strategy, with all numeric biomarker bands and vector details as non-clinical placeholders. We set this DDR-integrator hypothesis against mitochondria-, proteostasis-, and reprogramming-first models and pre-specify longitudinal, mediation, and head-to-head tests that could support, demote, or refute it. No integrated human interventional data yet exist; we therefore present a falsifiable research agenda, not a therapeutic protocol.

Link: https://doi.org/10.18632/aging.206416

Type 1 conventional dendritic cells are a subclass of dendritic cell known to be an important component of the immune response to pathogens and cancerous cells, particularly focused on stimulating the activity of cytotoxic T cells. The cancer research community, as is often the case when it comes to specific components of the immune system, has led the way in generating a better understanding of these cells, and so much of the present literature is focused on their role in cancer. Generally speaking, patients with more type 1 conventional dendritic cells tends to exhibit better outcomes, because the cancer will be more aggressively attacked by the immune system. Unfortunately, the population of type 1 conventional dendritic cells declines with age.

Today's open access paper assembles existing data to provide a coherent viewpoint on the interconnected mechanisms leading to the age-related loss of type 1 conventional dendritic cells, and proposes a readily available solution, albeit one involving cell therapy. A number of interventions assessed by the cancer research community have been shown to somewhat restore dendritic cell function, but none of them are sufficient because they each only address once small part of the overall cause of the loss of type 1 conventional dendritic cells. The authors of today's paper propose that an existing approach to the ex vivo production of type 1 conventional dendritic cells for anti-cancer cell therapy will solve the problem by providing cells that were not exposed to the specific changes in an aged biochemistry that form the root cause of the issue.

A proposed convergent molecular chain linking senescence, cancer, and chronic infection to a correctable failure of dendritic cell instruction

Three convergent phenomena in biomedical research have lacked a unified mechanistic explanation: the dendritic cell dysfunction of aging, the immune evasion of cancer, and the tolerogenic bias of chronic infection. In each setting, the specific cell responsible for instructing effector immunity, the type 1 conventional dendritic cell (cDC1), is numerically depleted, functionally silent, or both, leading to loss of its bioactive IL-12p70 output.

The cDC1 is defined at the lineage level by its dependence on the transcription factor IRF8, which is required for cDC1 specification, survival, and the capacity to produce IL-12p70. The IRF8 locus is regulated by a BATF3-dependent enhancer architecture that has been shown to operate as a bistable switch with no stable intermediate state: a committed cDC1 is either IRF8-high and surveillance-competent or IRF8-low and tolerogenic. The switch does not sit between these states. This architectural property is central to understanding why partial interventions have produced only partial results.

We propose that aging, cancer, and chronic infection converge on a single molecular chain that forces this switch into the off position. The chain has four steps, each of which is individually established in the published literature. Senescence-associated secretory phenotype (SASP) cytokines activate STAT3 in hematopoietic progenitors; STAT3 recruits DNMT1 and EZH2 to the IRF8 locus; dual DNA methylation and histone methylation installs a bistable silencing state with no stable intermediate; IL-12 transcription and cDC1 instruction collapse.

Any correction that leaves the upstream SASP intact and attempts to unlock IRF8 in situ must overcome both DNA methylation and H3K27me3 on a bistable locus whose low-affinity enhancer architecture is biased toward the off state. Pharmacological attempts to do this, DNMT inhibitors, EZH2 inhibitors, JAK/STAT3 inhibitors, IL-6 blockade, have produced partial restoration of dendritic-cell function in preclinical settings but not durable correction. The logic of the chain explains why: each of these interventions targets a single node while the remaining nodes continue to reinforce silencing.

An alternative approach bypasses the architecture rather than unlocking it. A cDC1 manufactured ex vivo in a STAT3-free environment, with IFN-γ priming and TLR3 engagement, is never exposed to the sustained STAT3 signal required for DNMT and EZH2 recruitment. Its IRF8 locus is not methylated because the conditions that drive methylation are absent from the bioreactor. The α-type-1 polarized dendritic cell (α-DC1) protocol developed in the early 2000s produces precisely such a cell. The α-DC1 protocol has been evaluated clinically, most directly in recurrent malignant glioma, within a broader body of dendritic-cell vaccine trials in melanoma and other solid tumors. The clinical data in these trials are consistent with the framework. Interpreted within the framework presented here, the α-DC1 functions as a replacement instructor for a cell population whose native equivalents have been silenced.

Suppression of cancer is a necessary component of species longevity, and finding out how exactly cancer incidence is in some cases dramatically reduced is one of the primary goals for the field of comparative biology. Here, researchers survey known cancer-associated sequences across the genomes of long-lived and short-lived species, and see that sequences are more conserved in long-lived species. Patterns of epigenetic modifications to the genome at these locations also exhibit differences in long-lived species. Thus one component of reduced cancer risk in these species involves specific sequence differences in oncogenes and related genes, and different expression of oncogenes in circumstances relevant to induction of cancer.

Recently, accumulated evidence has shown that longer-lived species, such as naked mole rats, elephants, and some bat species display enhanced resistance to cancer. In this study, we identify genomic sites in 58 mammalian species that are homologous to human cancer-associated regions and compare their evolutionary dynamics to those of cancer-unrelated sites. By contrasting mutation rates in longer-lived versus shorter-lived species, we evaluate whether evolutionary constraint at these loci correlates with lifespan or body size. Because epigenetic modifications are intimately linked to oncogenesis, and synonymous changes can affect tumorigenesis by perturbing m6A deposition, we also examine the distribution of 5mC and m6A marks at cancer-associated versus unrelated sites across the two lifespan groups.

While overall evolutionary rates at cancer-associated loci do not differ significantly between long-lived and short-lived species, cancer-associated sites show greater evolutionary conservation relative to non-cancer sites within long-lived mammals but not within short-lived mammals. Furthermore, long-lived species exhibit a pronounced enrichment of m6A at cancer-associated loci (based on m6A modification sites derived exclusively from male samples) despite lower global m6A levels. Notably, tumor suppressor genes in long-lived mammals harbor proportionally more m6A-modified transcripts, suggesting a potential association between messenger RNA methylation and post-transcriptional regulation at cancer-relevant loci. Together, these results suggest that enhanced sequence conservation at cancer loci, coupled with targeted mRNA modification, may be part of a multilayered molecular strategy that reduces cancer risk in long-lived mammals.

Link: https://doi.org/10.1038/s41467-026-76479-3

Here find a small slice of programmed aging consideration focused on some of the changes in cognitive function that take place in later life. The researchers argue that a shift in focus to integration of information, characterized by a loss of precision in episodic memory, is adaptive and selected for in older individuals. It is an interesting point of view, though given the tools the research community has today it would be challenging to determine whether any specific age-related alteration in neural circuitry and cognitive function in the brain is adaptive change versus change that is a response to damage and loss of function.

Prevailing theories of cognitive aging depict late life as a period of compensatory decline - an effort to preserve performance despite progressive neural deterioration. We propose instead that aging represents a continuation of development: a genetically conserved, adaptive reorganization of memory systems that parallels the brain's earlier-life transitions. Drawing on convergent molecular, network, behavioral, and comparative evidence, we argue that the well-documented decline in episodic-memory precision reflects a deliberate recalibration of plasticity from hippocampal to cortical circuits, favoring semantic integration and schematic stability over rapid encoding of novel details.

This shift, we suggest, is not a workaround for loss but an evolved optimization suited to the cognitive ecology of late life, when accumulated knowledge, social insight, and intergenerational teaching become primary adaptive functions. The resulting semantic mode of cognition supports narrative coherence, emotional regulation, and wisdom, distinguishing normal aging from pathological derailments such as Alzheimer's disease. We outline testable predictions across longitudinal, neuroimaging, and computational domains and reinterpret constructs like cognitive reserve as expressions of this developmental reallocation. By reframing aging as purposeful maturation rather than compensation, the adaptive-aging hypothesis positions late-life cognition as a distinct, evolutionarily honed phase of human development.

Link: https://doi.org/10.1177/17456916261469175

It is well understood in the aging research community that the lack of a useful, consensus measure of biological age or pace of biological aging is a considerable hindrance to progress. If researchers could quickly measure the pace of aging or the state of aging in a robust way, then discovery and optimization of interventions would proceed a great deal more rapidly. At present, too many suboptimal lines of research are maintained despite the likely lack of effectiveness at the end of the day, and the discovery of new approaches to slow aging and extend life is a slow and expensive process; even in mice, life span studies take years to run.

There are a great many age-related changes in health, biochemistry, and physical function that can be measured, and many of those have their advocates. The "just measure grip strength and get on with it already" faction is a sizable one. Various aging clocks produce decent correlations with age-related mortality and morbidity. And so forth. But the challenge with all of the existing options is that we have no idea as whether then can be trusted to accurately reflect the effects of any new class of intervention. Maybe they will overstate the outcome. Maybe they will understate it. The only way to find out is to calibrate assays against interventions in long-running and expensive studies. And so development remains stuck in the slow lane.

In today's open access paper, researchers propose one possible way forward to an incrementally better situation. The idea is to look through the existing high quality studies of slowed aging in mice conducted by the Interventions Testing Program, and find common biochemical and metabolic measures that appear in mice exhibiting slowed aging. This seems relevant to the classes of therapy that slow aging by provoking cellular stress responses, repair and maintenance and defense activities that improve cell function: calorie restriction, calorie restriction mimetics, and the like. It seems tough to argue that metrics uncovered via these studies could then be applied to completely different approaches to therapy that do not touch on these shared stress response systems, such as senolytics or stem cell therapies, however.

Aging rate indicators and the search for anti-aging drugs

Evidence that drugs, diets, and single-gene mutations can slow aging and extend the healthy lifespan of mammals has begun to convert biogerontology from an observational science into one based on interventions that could provide people with additional years of healthy, productive life. However, the research and development of anti-aging drugs is hampered by the lack of instantaneous and continuous measures of the rate of aging itself. This article presents recent work on anti-aging drugs that are effective in mice, provides evidence for candidate "aging rate indicators" (ARIs), and outlines a roadmap for translating these into clinical research to slow aging in humans.

Thus far, 14 agents or combinations have significantly increased the lifespan of mice in studies conducted under the Interventions Testing Program (ITP) of the National Institute on Aging, often when initiated in late adulthood. Recent evidence suggests that many, perhaps all, interventions that slow aging in mice induce common, shared changes in physiological status and molecular pathways. We have proposed 12 such mechanisms as candidate ARIs, i.e., measurable outcomes that reflect a slow-aging state and that could discriminate between normal mice (and perhaps humans) and those exposed to effective anti-aging interventions - thereby accelerating research.

Research priorities now include testing the robustness of these ARIs, extending them to include plasma constituents, elucidating the mechanisms through which diverse interventions alter them, uncovering the links between the ARIs and late-life diseases, and extending research to dogs, non-human primates, and humans. The growing recognition of the legitimacy and promise of evidence-based interventions resulting from aging biology should elevate this field to a level of urgency and respect comparable to that of current research on individual age-related conditions.

Researchers have started on the long process of transferring promising genes from long-lived species into short-lived species, one by one, with each such transfer as a test of how important that specific difference is to the progression of aging and species longevity. Differences in the presence of hyaluronan in the extracellular matrix are thought to improve the health and resilience of long-lived naked-mole rats, and so researchers generated a mouse lineage that manufactures naked mole rat hyaluronan. The result is improved healthspan, and so now researchers are beginning to assess this novel lineage of mice more deeply. Here, for example, researchers show that this alteration to hyaluronan doesn't have any effect on age-related hearing loss.

Approximately one in three adults aged 65-74 years reports hearing difficulty, including age-related hearing loss (AHL, presbycusis). The C57BL/6 mouse is widely used in preclinical AHL research because it develops AHL relatively early. Calorie restriction (CR) attenuates AHL and improves healthspan and longevity in this strain. A recently developed transgenic C57BL/6 mouse expressing naked mole-rat hyaluronan synthase 2 (nmrHas2), which produces very high molecular mass hyaluronan (vHMM-HA), also exhibits improved healthspan, reduced inflammaging, and increased longevity. Therefore, we evaluated nmrHas2 mice for evidence of alleviated AHL.

The goal of this experiment was to determine whether ubiquitous expression of the nmrHas2 transgene, including within the cochleae, attenuated AHL. Our results indicate that a genetic intervention that had previously been shown to improve healthspan, reduce inflammaging, and increase longevity in C57BL/6 mice did not attenuate AHL, i.e., these outcomes were decoupled in nmrHas2 mice, which contrasts with outcomes following CR. This points to differences in the mechanisms of action of these two interventions, at least within the cochleae.

Link: https://doi.org/10.3389/fragi.2026.1936677

Many approaches to modestly slow aging in short-lived species involve a mild mitochondrial dysfunction that that somewhat increases the level of reactive oxygen species generated in the course of producing adenosine triphosphate (ATP) to power the cell. Reactive oxygen species react with and damage molecular machinery throughout the cell, damage that needs to be repaired. The cell reacts with an increase in repair and maintenance activities that address oxidative damage and other forms of damage, producing a net benefit to function. Here, researchers investigate one portion of how this response is regulated, looking at the metabolism of nematode worms.

The reactive oxygen species superoxide is generated by mitochondria during the process of producing energy. While superoxide can cause oxidative damage to the cell, we and others have shown that a mild increase in mitochondrial superoxide extends longevity in multiple model organisms. To elucidate the molecular mechanisms involved, we identified transcriptional changes in mitochondrial superoxide dismutase deletion mutants (sod-2 worms) using RNA sequencing. sod-2 mutants exhibit a number of changes in nuclear gene expression resulting from elevated mitochondrial superoxide suggesting that mitochondria-to-nucleus signaling is contributing to their longevity.

Gene ontology enrichment analysis demonstrated that genes involved in innate immunity and cuticle formation are significantly upregulated in sod-2 worms. To identify kinases involved in this lifespan-extending pathway, we completed a targeted RNA interference screen to examine the contribution of selected kinases to sod-2 longevity. From this screen, we found 25 kinases which are required for the long lifespan of sod-2 mutants including mak-2, which has a role in a kinase signaling pathway involved in axon regeneration. Disruption of mak-2 specifically reduces sod-2 lifespan but not wild-type longevity and also decreases resistance to multiple exogenous stressors. In examining other genes that act with mak-2 in established signaling pathways, we identified a SEK-3/PMK-3/MAK-2/CEBP-1 signaling pathway that is specifically required for sod-2 longevity but not wild-type lifespan.

Combined these results suggest a novel role for kinases with established roles in axon regeneration in promoting longevity through a mitochondria-to-nucleus signaling pathway.

Link: https://doi.org/10.1016/j.redox.2026.104385