Longevity Papers

The transcription factor CCAAT/enhancer binding protein alpha (C/EBP) regulates cell differentiation, proliferation, and function in various tissues, including the liver, adipose tissue, skin, lung, and hematopoietic system. Studies in rats, mice, humans, and chickens have shown that CEBPA mRNA undergoes alternative translation initiation, producing three C/EBP protein isoforms. Two of these isoforms act as full-length transcription factors with N-terminal transactivation domains and a C-terminal dimerization and DNA-binding domains. The third isoform is an N-terminally truncated variant, translated from a downstream AUG codon. It competes with full-length isoforms for DNA binding, thereby antagonizing their activity. Expression of the truncated C/EBP isoform depends on the initial translation of a short upstream open reading frame (uORF) in CEBPA mRNA and subsequent re-initiation at a downstream AUG codon, a process stimulated by mTORC1 signaling. We investigated whether the ortholog of the CEBPA gene in the evolutionarily distant, short-lived African turquoise killifish (Nothobranchius furzeri) is regulated by similar mechanisms. Our findings reveal that the uORF-mediated regulation of C/EBP isoform expression is conserved in killifish. Disruption of the uORF selectively eliminates the truncated isoform, leading to unrestrained activity of the full-length C/EBP isoforms. This genetic modification significantly extended both the median and maximal lifespan and improved the healthspan of male N. furzeri. These results highlight a conserved mechanism of CEBPA gene regulation across species and its potential role in modulating the lifespan and aging phenotypes.

Pulmonary Fibrosis (PF) is a life-threatening illness that is characterized by progressive scarring in the lung interstitium. There is an urgent need for new PF therapies because current treatments only slow down the progression of fibrosis and the median life expectancy post-diagnosis is only 4 to 6 years. Since PF patients frequently exhibit telomere attrition, overexpressing telomerase, the enzyme responsible for synthesizing telomeres represents a compelling therapeutic option. In this study, we in vitro transcribed human telomerase reverse transcriptase (hTERT) mRNA using modified nucleosides (modRNA). ModRNA hTERT treatment led to transient activation of telomerase activity in a dose-dependent manner in MRC-5 cells and, importantly, in primary human alveolar type II pneumocytes (ATII cells). Consequently, the proliferative capacity was increased, concomitant with reduced DNA damage and elongated telomere length. Notably, induction of cellular immune response was only detectable at the highest modRNA concentration, and returned to normal levels within 48 hours. Next, we demonstrated that circularized, exonuclease-resistant modRNA hTERT extended the transient expression profile which may be clinically advantageous. Finally, we provided therapeutic proof of concept in organotypic 3D ex vivo human precision-cut lung slices derived from end-stage PF patients. Intriguingly, a single modRNA hTERT treatment inhibited senescence as indicated by significantly lower levels of senescence-associated {beta}-galactosidase, and pro-inflammatory IL6 and IL8. Concurrently, the key fibrosis mediators TGF{beta} and COL1A1 were markedly reduced. In conclusion, the data presented herein provide initial evidence for the potential of RNA-based hTERT therapy for treating human lung fibrosis.

Oxidative stress plays a key role in aging and related diseases, including neurodegeneration, cancer, and organ failure. Copper (Cu), a redox-active metal ion, generates reactive oxygen species (ROS), and its dysregulation contributes to aging. Here, we develop activity-based imaging probes for the sensitive detection of Cu(I) and show that labile hepatic Cu activity increases with age, paralleling a decline in ALDH1A1 activity, a protective hepatic enzyme. We also observe an age-related decrease in hepatic glutathione (GSH) activity through noninvasive photoacoustic imaging. Using these probes, we perform longitudinal studies in aged mice treated with ATN-224, a Cu chelator, and demonstrate that this treatment improves Cu homeostasis and preserves ALDH1A1 activity. Our findings uncover a direct link between Cu dysregulation and aging, providing insights into its role and offering a therapeutic strategy to mitigate its effects.

Both environmental exposures and genetics are known to play important roles in shaping human aging. Here we aimed to quantify the relative contributions of environment (referred to as the exposome) and genetics to aging and premature mortality. To systematically identify environmental exposures associated with aging in the UK Biobank, we first conducted an exposome-wide analysis of all-cause mortality (n = 492,567) and then assessed the associations of these exposures with a proteomic age clock (n = 45,441), identifying 25 independent exposures associated with mortality and proteomic aging. These exposures were also associated with incident age-related multimorbidity, aging biomarkers and major disease risk factors. Compared with information on age and sex, polygenic risk scores for 22 major diseases explained less than 2 percentage points of additional mortality variation, whereas the exposome explained an additional 17 percentage points. Polygenic risk explained a greater proportion of variation (10.3-26.2%) compared with the exposome for incidence of dementias and breast, prostate and colorectal cancers, whereas the exposome explained a greater proportion of variation (5.5-49.4%) compared with polygenic risk for incidence of diseases of the lung, heart and liver. Our findings provide a comprehensive map of the contributions of environment and genetics to mortality and incidence of common age-related diseases, suggesting that the exposome shapes distinct patterns of disease and mortality risk, irrespective of polygenic disease risk.

Assessing impact on the hallmarks of aging has emerged as a novel method for prioritizing dual-purpose longevity therapeutic targets and developing drugs simultaneously targeting aging and disease. Cellular senescence, a central hallmark of aging, progressively induces cellular growth arrest and accelerates the production of a pro-inflammatory senescence-associated secretory phenotype (SASP). TGF-β signaling is situated at the center of multiple senescence-associated and aging-associated signaling pathways, and its inhibition may be favorable for aging-related disorders. A recently developed Traf2- and Nck-interacting kinase (TNIK) inhibitor, INS018_055, was identified as a potent, novel anti-fibrotic agent affecting multiple hallmarks of aging across fibrotic diseases. Thus, we hypothesized that TNIK is a potential senescence modulator and INS018_055 could attenuate senescent cell accumulation to treat specific age-related pathological processes. Using a fully automated robotics laboratory designed for automated, highly parallel, and iterative phenotypic and multi-omic analyses, we determined that pharmacological or siRNA-mediated TNIK inhibition decreased cellular senescence in multiple experimental senescence models. INS018_055 mechanistically demonstrated senomorphic activity through its reduction of SASP. Furthermore, transcriptomics analysis revealed that INS018_055 treatment reduced aging signatures and extracellular matrix fibronectin through TGF-β signaling. These findings reveal TNIK's previously unappreciated role in cellular senescence and INS018_055's senomorphic potential in mitigating processes well-established as driving organismal aging. Thus, TNIK inhibition as a novel senomorphic strategy may inform future therapeutic approaches for diverse aging-related diseases.

As the only gateway governing nucleocytoplasmic transport, the nuclear pore complex (NPC) maintains fundamental cellular processes and deteriorates with age. However, the study of age-related roles of single NPC components remains challenging owing to the complexity of NPC composition. Here we demonstrate that the master energy sensor, AMPK, post-translationally regulates the abundance of the nucleoporin NPP-16/NUP50 in response to nutrient availability and energetic stress. In turn, NPP-16/NUP50 promotes transcriptomic activation of lipid catabolism to extend the lifespan of Caenorhabditis elegans independently of its role in nuclear transport. Rather, the intrinsically disordered region (IDR) of NPP-16/NUP50, through direct interaction with the transcriptional machinery, transactivates the promoters of catabolic genes. Remarkably, elevated NPP-16/NUP50 levels are sufficient to promote longevity and metabolic stress defenses. AMPK-NUP50 signaling is conserved to human, indicating that bridging energy sensing to metabolic adaptation is an ancient role of this signaling axis.