Fight Aging!

You might recall that gene therapy to overexpress caveolin-1 in the brain was recently shown to reduce pathology in a mouse model of Alzheimer's disease. In today's open access paper, researchers apply the same gene therapy to a mouse model of TDP-43 pathology in the aging brain. In this model, the mice express higher than normal levels of TDP-43, and thus as they age, the animals exhibit greater levels of altered forms of TDP-43 that form aggregates and disrupt cell biochemistry in the brain as a consequence. This pathological aggregation and its consequences are particularly important in amyotrophic lateral sclerosis (ALS) and the recently named limbic-predominant age-related TDP-43 encephalopathy (LATE), but it seems likely that TDP-43 aggregation contributes in some way to all of the major named age-related neurodegenerative conditions.

Of note, the viral vector used in these studies, AAV-PHP.eB, is a relatively recently developed AAV serotype that allows for both intravenous injection and efficient transduction of cells in the brain. From a logistics and cost perspective, this is a large improvement over the need for stereotactic approaches to direct injection of the brain and intrathecal injections, and is spurring more interest in the development brain targeted gene therapies.

The mechanism by which increased caveolin-1 expression improves function in a brain undergoing neurodegenerative issues is quite interesting; it seems more suited to TDP-43 pathology than Alzheimer's pathology, as one might argue that it is actually doing something to mitigate much of the core problem of TDP-43 alteration and mislocalization, rather than only compensating for root causes by enabling greater synaptic plasticity, as seems more the case in the Alzheimer's disease models.

Systemic delivery of synapsin-promoted caveolin-1 overexpression ameliorates pathological TDP-43-induced cognitive decline and neurodegenerative changes

Transactive response DNA-binding protein 43 (TDP-43) proteinopathy is associated with frontotemporal dementia and Alzheimer's disease (AD). We previously demonstrated that synapsin-promoted caveolin-1 (SynCav1) preserves cognitive function in the mouse model of AD. This study investigated the therapeutic potential of SynCav1 in a mouse model of TDP-43 proteinopathy. AAV-PhP.eB-SynCav1 was delivered systemically to the TDP-43A315T mouse, followed by cognitive evaluation and biochemical and ultrastructural analysis of brain tissue.

Systemic AAV-PhP.eB-SynCav1 gene therapy efficiently crossed the blood-brain barrier and achieved central nervous system-wide neuroprotection. Mechanistically, pathological TDP-43 mislocalized to membrane lipid rafts (MLRs), resulting in decreased MLR-associated GluN2A expression and degenerative changes in neuronal ultrastructure. In contrast, SynCav1 delivery alleviated TDP-43 mislocalization on MLRs, stabilized MLR-associated GluN2A expression, and preserved synaptic ultrastructure. Furthermore, SynCav1 mitigated TDP-43-induced mitochondrial hyper-fragmentation and excessive mitochondrial fission signaling.

These findings establish a novel link between TDP-43 proteinopathy and MLR instability, supporting SynCav1 as a "neuron-centric" candidate for treating TDP-43-related neurodegeneration.

Macular degeneration involves the death of vital cells in the retina, leading to progressive blindness. The less common neovascular (or "wet") form of the condition involves the inappropriate growth of leaky blood vessels in the retina and underlying choroid. Existing treatments focus on trying to prevent this blood vessel growth or remove the vessels, rather than addressing underlying causes. Here, researchers make a step in the direction of those underlying causes by identifying a problem immune cell population that appears to contribute to the dysfunction and leakage of blood vessels in the eye.

Age-related macular degeneration (AMD) is the leading cause of irreversible central blindness and can result in pathological neovascularization. Using a "human-first" approach, we identify immunotherapy as a disease modifier in models of neovascular AMD. Plasma cytokine analysis in a large population cohort reveals an imbalance of lymphocytic cytokines associated with severity of AMD, leading to discovery of a skewed peripheral natural killer (NK) cell phenotype in individuals with AMD.

Peripheral NK cells are rapidly activated in neovascular AMD models, and single-cell RNA sequencing demonstrates expansion of activated cytolytic NK cells within neovascular lesions during resolution. NK cells localize to neovessels in human AMD donor eyes; however, they exhibit markers of terminal differentiation and quiescence. Adoptive transfer of pre-activated NK cells reduces neovascularization and restores barrier integrity. Our data identify a distinct, functionally altered NK cell phenotype in neovascular AMD and suggests harnessing NK cells represents an immunotherapeutic alternative for the treatment of neovascular AMD.

Link: https://doi.org/10.1016/j.xcrm.2026.102792

Researchers continue to produce new aging clocks at a fair pace. Any sufficiently complex set of biological data obtained from people of various ages can yield a clock given the use of various forms of machine learning. It is straightforward to make a new clock. Most of these will vanish into obscurity, as they will demonstrate no advantages over existing, more well studied clocks. The need is not for new clocks, but to solve the challenges inherent in the use of any clock, which is to say that it is entirely unclear as to whether a clock provides a reasonable representation of biological aging, and whether it can be trusted as an assessment of any given intervention to slow or reverse aspects of aging. The research community struggles to connect clock parameters to aging in any meaningful way that yields confidence in the ability of a clock to assess novel forms of therapy.

Amino acids are fundamental to human physiology, yet their impact on growth, development, and aging remains elusive. Here, we introduce AmiAge, a biological age predictor constructed using a Random Forest model trained on the concentrations of 18 amino acids across individuals aged 1 to 89 years. Leveraging data from 9 studies encompassing over 11,000 in-house and more than 270,000 publicly available samples with diverse demographic and genetic backgrounds,

AmiAge demonstrates robust accuracy. The deviation between AmiAge and chronological age (AmiAge Gap) correlates strongly with established aging biomarkers, disease risk, and clinical outcomes. Individuals with higher gaps exhibit increased frailty, telomere attrition, and elevated incidence of age-related diseases. To enhance clinical utility, we distilled AmiAge into an 8-amino acid model (including alanine, glutamine, glycine, histidine, leucine, phenylalanine, tyrosine, and valine). Our findings suggest that this simple, scalable amino acid clock offers a valuable complement to existing biological aging metrics, with potential applications in personalized health management and aging research.

Link: https://doi.org/10.1038/s41467-026-73371-y