Targeting iron-associated protein Ftl1 in the brain of old mice improves age-related cognitive impairment.

Understanding cellular and molecular drivers of age-related cognitive decline is necessary to identify targets to restore cognition at old age. Here we identify ferritin light chain 1 (FTL1), an iron-associated protein, as a pro-aging neuronal factor that impairs cognition. Using transcriptomic and mass spectrometry approaches, we detect an increase in neuronal FTL1 in the hippocampus of aged mice, the levels of which correlate with cognitive decline.

Serum amyloid P secreted by bone marrow adipocytes drives skeletal amyloidosis.

The accumulation of amyloid fibrils has been identified in tissues outside the brain, yet little is understood about the formation of extracerebral amyloidosis and its impact on organ aging. Here, we demonstrate that both transgenic Alzheimer's disease (AD) mice and naturally aging mice exhibit accumulated senescent bone marrow adipocytes (BMAds), accompanied by amyloid deposits. Senescent BMAds acquire a secretory phenotype, markedly increasing secretion of serum amyloid P component (SAP), also known as pentraxin 2 (PTX2).

Senescent macrophages induce ferroptosis in skeletal muscle and accelerate osteoarthritis-related muscle atrophy.

Muscle atrophy around joints is a common issue for people with osteoarthritis (OA), but its causes are poorly understood. Here we demonstrate that chronic inflammation in quadriceps muscle coincides with OA in mice, characterized by an increase in macrophages, activation of inflammatory pathways and tissue vascularization. We show that, during OA progression, macrophages progressively exhibit increasing phenotypes of senescence and promote muscle atrophy through paracrine induction of ferroptosis.

Boosting angiotensin-converting enzyme (ACE) in microglia protects against Alzheimer's disease in 5xFAD mice.

Genome-wide association studies have identified many gene polymorphisms associated with an increased risk of developing late-onset Alzheimer's disease (LOAD). Many of these LOAD risk-associated alleles alter disease pathogenesis by influencing innate immune responses and lipid metabolism of microglia (MG). Here we show that boosting the expression of angiotensin-converting enzyme (ACE), a genome-wide association study LOAD risk-associated gene product, specifically in MG, reduces amyloid-β (Aβ) plaque load, preserves vulnerable neurons and excitatory synapses, and significantly reduces learning and memory abnormalities in the 5xFAD amyloid mouse model of AD.

A blood-based epigenetic clock for intrinsic capacity predicts mortality and is associated with clinical, immunological and lifestyle factors.

Age-related decline in intrinsic capacity (IC), defined as the sum of an individual's physical and mental capacities, is a cornerstone for promoting healthy aging by prioritizing maintenance of function over disease treatment. However, assessing IC is resource-intensive, and the molecular and cellular bases of its decline are poorly understood. Here we used the INSPIRE-T cohort (1,014 individuals aged 20-102 years) to construct the IC clock, a DNA methylation-based predictor of IC, trained on the clinical evaluation of cognition, locomotion, psychological well-being, sensory abilities and vitality.

The geroprotectors trametinib and rapamycin combine additively to extend mouse healthspan and lifespan.

Suppression of the insulin-IGF-mTORC1-Ras network ameliorates aging in animals. Many drugs have targets in the network because of its roles in cancer and metabolic disease and are candidates for repurposing as geroprotectors. Rapamycin, an established geroprotective drug, blocks mTORC1 signaling, and trametinib inhibits the Ras-MEK-ERK pathway.

Mitochondrial clonal mosaicism encodes a biphasic molecular clock of aging.

Mitochondria rapidly accumulate mutations throughout a lifetime, potentially acting as a molecular clock for aging and disease. We profiled mitochondrial RNA across 47 human tissues from 838 individuals, revealing rapid development of clonal mosaicism with two distinct tissue-specific aging signatures. Tissues with constant cellular turnover such as the gastrointestinal tract or skin exhibit accelerated accumulation of sporadic mutations and clonal expansions, implicating increased susceptibility to age-related tumorigenesis and dysfunction.

Vitamin D and marine ω-3 fatty acids supplementation and leukocyte telomere length: 4-year findings from the VITamin D and OmegA-3 TriaL (VITAL) randomized controlled trial.

Background: Limited studies suggest that vitamin D or omega 3 fatty acids (n-3 FAs) supplementation may be beneficial for telomere maintenance, however, evidence from large randomized clinical trial is lacking.

Objective: We aimed to determine whether vitamin D or n-3 FAs supplementation reduce leukocyte telomere length (LTL) attrition over time by leveraging the VITamin D and OmegA-3 TriaL (VITAL) trial.

Methods: VITAL is a large, randomized, double-blind, placebo-controlled tr ial with a 2 x 2 factorial design of vitamin D3 (2,000 IU/day) and marine n-3 FAs (1 g/day) supplements for 5 years among a representative sample of 25,871 US females ≥55 and males ≥50 years of age.

Pre-symptomatic Parkinson's disease blood test quantifying repetitive sequence motifs in transfer RNA fragments.

Early, efficient Parkinson's disease (PD) tests may facilitate pre-symptomatic diagnosis and disease-modifying therapies. Here we report elevated levels of PD-specific transfer RNA fragments carrying a conserved sequence motif (RGTTCRA-tRFs) in the substantia nigra, cerebrospinal fluid and blood of patients with PD. A whole blood qPCR test detecting elevated RGTTCRA-tRFs and reduced mitochondrial-originated tRFs (MT-tRFs) segregated pre-symptomatic patients with PD from controls (area under the receiver operating characteristic curve (ROC-AUC) of 0.

Regeneration leads to global tissue rejuvenation in aging sexual planarians.

The possibility of reversing the adverse impacts of aging could significantly reduce age-related diseases and improve quality of life in older populations. Here we report that the sexual lineage of the planarian Schmidtea mediterranea exhibits physiological decline within 18 months of birth, including altered tissue architecture, impaired fertility and motility, and increased oxidative stress. Single-cell profiling of young and older planarian heads uncovered loss of neurons and muscle, increase of glia, and revealed minimal changes in somatic pluripotent stem cells, along with molecular signatures of aging across tissues.

Epigenetic editing at individual age-associated CpGs affects the genome-wide epigenetic aging landscape.

Aging is reflected by genome-wide DNA methylation changes, which form the basis of epigenetic clocks, but it is largely unclear how these epigenetic modifications are regulated and whether they directly affect the aging process. In this study, we performed epigenetic editing at age-associated CpG sites to explore the consequences of interfering with epigenetic clocks. CRISPR-guided editing targeted at individual age-related CpGs evoked genome-wide bystander effects, which were highly reproducible and enriched at other age-associated regions.

Interleukin-12 signaling drives Alzheimer's disease pathology through disrupting neuronal and oligodendrocyte homeostasis.

Neuroinflammation including interleukin (IL)-12/IL-23-signaling is central to Alzheimer's disease (AD) pathology. Inhibition of p40, a subunit of IL-12/IL-23, attenuates pathology in AD-like mice; however, its signaling mechanism and expression pattern remained elusive. Here we show that IL-12 receptors are predominantly expressed in neurons and oligodendrocytes in AD-like APPPS1 mice and in patients with AD, whereas IL-23 receptor transcripts are barely detectable.

Characterizing Olfactory Brain Responses in Young Infants.

Odor perception plays a critical role in early human development, but the underlying neural mechanisms are not fully understood. To investigate these, we presented appetitive and aversive odors to infants of both sexes at 1 month of age while recording functional magnetic resonance imaging (fMRI) and nasal airflow data. Infants slept during odor presentation to allow MRI scanning.

Cohort trends in intrinsic capacity in England and China.

To understand how the health of older adults today compares to that of previous generations, we estimated intrinsic capacity and subdomains of cognitive, locomotor, sensory, psychological and vitality capacities in participants of the English Longitudinal Study of Ageing and the China Health and Retirement Longitudinal Study. Applying multilevel growth curve models, we found that more recent cohorts entered older ages with higher levels of capacity, while subsequent age-related declines were somewhat compressed compared to earlier cohorts. Trends were most evident for the cognitive, locomotor and vitality capacities.

IL-23R is a senescence-linked circulating and tissue biomarker of aging.

Cellular senescence is an aging mechanism characterized by cell cycle arrest and a senescence-associated secretory phenotype (SASP). Preclinical studies demonstrate that senolytic drugs, which target survival pathways in senescent cells, can counteract age-associated conditions that span several organs. The comparative efficacy of distinct senolytic drugs for modifying aging and senescence biomarkers in vivo has not been demonstrated.

A mortality timer based on nucleolar size triggers nucleolar integrity loss and catastrophic genomic instability.

Genome instability is a hallmark of aging, with the highly repetitive ribosomal DNA (rDNA) within the nucleolus being particularly prone to genome instability. Nucleolar enlargement accompanies aging in organisms ranging from yeast to mammals, and treatment with many antiaging interventions results in small nucleoli. Here, we report that an engineered system to reduce nucleolar size robustly extends budding yeast replicative lifespan in a manner independent of protein synthesis rate or rDNA silencing.

Effect of nicotinamide riboside on airway inflammation in COPD: a randomized, placebo-controlled trial.

Chronic obstructive pulmonary disease (COPD) is a progressive, incurable disease associated with smoking and advanced age, ranking as the third leading cause of death worldwide. DNA damage and loss of the central metabolite nicotinamide adenine dinucleotide (NAD) may contribute to both aging and COPD, presenting a potential avenue for interventions. In this randomized, double-blind, placebo-controlled clinical trial, we treated patients with stable COPD (n = 40) with the NAD precursor nicotinamide riboside (NR) for 6 weeks and followed-up 12 weeks later.

Age-related changes in gait, balance, and strength parameters: A cross-sectional study.

Background: Longevity is increasing worldwide due to improvements in healthcare and living standards. Aging is often associated with disability and multiple health concerns. To address these challenges, effective interventions are essential.

Implausibility of radical life extension in humans in the twenty-first century.

Over the course of the twentieth century, human life expectancy at birth rose in high-income nations by approximately 30 years, largely driven by advances in public health and medicine. Mortality reduction was observed initially at an early age and continued into middle and older ages. However, it was unclear whether this phenomenon and the resulting accelerated rise in life expectancy would continue into the twenty-first century.

Nonlinear dynamics of multi-omics profiles during human aging.

Aging is a complex process associated with nearly all diseases. Understanding the molecular changes underlying aging and identifying therapeutic targets for aging-related diseases are crucial for increasing healthspan. Although many studies have explored linear changes during aging, the prevalence of aging-related diseases and mortality risk accelerates after specific time points, indicating the importance of studying nonlinear molecular changes.

Single-nucleus sequencing reveals enriched expression of genetic risk factors in extratelencephalic neurons sensitive to degeneration in ALS.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by a progressive loss of motor function linked to degenerating extratelencephalic neurons/Betz cells (ETNs). The reasons why these neurons are selectively affected remain unclear. Here, to understand the unique molecular properties that may sensitize ETNs to ALS, we performed RNA sequencing of 79,169 single nuclei from cortices of patients and controls.

Conserved epigenetic hallmarks of T cell aging during immunity and malignancy.

Chronological aging correlates with epigenetic modifications at specific loci, calibrated to species lifespan. Such 'epigenetic clocks' appear conserved among mammals, but whether they are cell autonomous and restricted by maximal organismal lifespan remains unknown. We used a multilifetime murine model of repeat vaccination and memory T cell transplantation to test whether epigenetic aging tracks with cellular replication and if such clocks continue 'counting' beyond species lifespan.

Aging clocks based on accumulating stochastic variation.

Aging clocks have provided one of the most important recent breakthroughs in the biology of aging, and may provide indicators for the effectiveness of interventions in the aging process and preventive treatments for age-related diseases. The reproducibility of accurate aging clocks has reinvigorated the debate on whether a programmed process underlies aging. Here we show that accumulating stochastic variation in purely simulated data is sufficient to build aging clocks, and that first-generation and second-generation aging clocks are compatible with the accumulation of stochastic variation in DNA methylation or transcriptomic data.

A conserved complex lipid signature marks human muscle aging and responds to short-term exercise.

Studies in preclinical models suggest that complex lipids, such as phospholipids, play a role in the regulation of longevity. However, identification of universally conserved complex lipid changes that occur during aging, and how these respond to interventions, is lacking. Here, to comprehensively map how complex lipids change during aging, we profiled ten tissues in young versus aged mice using a lipidomics platform.