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The deacetylase SIRT6 reduces amyloid pathology and supports cognition in mice by reducing the stability of APP in neurons
Alzheimer's disease (AD) is an aging-related neurodegenerative disorder that results in progressively impaired memory and is often associated with amyloid plaques. Previous studies implicate the deacetylases SIRT1 and SIRT2 in regulating the processing of amyloid precursor protein (APP). Here, we investigated whether APP is regulated by the related deacetylase SIRT6, which shows aging-associated decreases in activity. We found that the abundance of SIRT6 was reduced in the cortex and hippocampus...
Spatial organizations of heterochromatin underpin nuclear structural integrity of ventricular cardiomyocytes against mechanical stress
Cardiomyocyte (CM) nuclei are constantly exposed to mechanical stress, but how they maintain their nuclear shape remains unknown. In this study, we found that ventricular CM nuclei acquire characteristic prominent spatial organizations of heterochromatin (SOH), which are disrupted by high-level expression of H2B-mCherry in mice. SOH disruption was associated with nuclear softening, leading to extreme elongation and rupture under unidirectional mechanical stress. Loosened chromatin then leaks...
The deacetylase SIRT6 reduces amyloid pathology and supports cognition in mice by reducing the stability of APP in neurons
Alzheimer's disease (AD) is an aging-related neurodegenerative disorder that results in progressively impaired memory and is often associated with amyloid plaques. Previous studies implicate the deacetylases SIRT1 and SIRT2 in regulating the processing of amyloid precursor protein (APP). Here, we investigated whether APP is regulated by the related deacetylase SIRT6, which shows aging-associated decreases in activity. We found that the abundance of SIRT6 was reduced in the cortex and hippocampus...
Comprehensive whole-genome sequencing reveals origins of mutational signatures associated with aging, mismatch repair deficiency and temozolomide chemotherapy
In a comprehensive study to decipher the multi-layered response to the chemotherapeutic agent temozolomide (TMZ), we analyzed 427 genomes and determined mutational patterns in a collection of ∼40 isogenic DNA repair-deficient human TK6 lymphoblast cell lines. We first demonstrate that the spontaneous mutational background is very similar to the aging-associated mutational signature SBS40 and mainly caused by polymerase zeta-mediated translesion synthesis (TLS). MSH2-/- mismatch repair (MMR)...
Metaxin-2 tunes mitochondrial transportation and neuronal function in Drosophila
Metaxins are a family of evolutionarily conserved proteins that reside on the mitochondria outer membrane (MOM) and participate in the protein import into the mitochondria. Metaxin-2 (Mtx2), a member of this family, has been identified as a key component in the machinery for mitochondrial transport in both C. elegans and human neurons. To deepen our understanding of Mtx2's role in neurons, we examined the homologous genes CG5662 and CG8004 in Drosophila. The CG5662 is a non-essential gene while...
Microglial lipid phosphatase SHIP1 limits complement-mediated synaptic pruning in the healthy developing hippocampus
The gene inositol polyphosphate-5-phosphatase D (INPP5D), which encodes the lipid phosphatase SH2-containing inositol polyphosphate 5-phosphatase 1 (SHIP1), is associated with the risk of Alzheimer's disease (AD). How it influences microglial function and brain physiology is unclear. Here, we showed that SHIP1 was enriched in early stages of healthy brain development. By combining in vivo loss-of-function approaches and proteomics, we discovered that mice conditionally lacking microglial SHIP1...
Decoding aging clocks: New insights from metabolomics
Chronological age is a crucial risk factor for diseases and disabilities among older adults. However, individuals of the same chronological age often exhibit divergent biological aging states, resulting in distinct individual risk profiles. Chronological age estimators based on omics data and machine learning techniques, known as aging clocks, provide a valuable framework for interpreting molecular-level biological aging. Metabolomics is an intriguing and rapidly growing field of study,...
Downregulation of MLF1 safeguards cardiomyocytes against senescence-associated chromatin opening
Aging-associated cardiac hypertrophy (AACH) increases susceptibility to heart failure in the elderly. Chromatin remodeling contributes to the gene reprogramming in AACH; however, the intrinsic regulations remain elusive. We performed a transcriptome analysis for AACH in comparison with pressure-overload-induced pathological cardiac hypertrophy in mice and identified myeloid leukemia factor 1 (MLF1) as an aging-sensitive factor whose expression was reduced during aging but could be reversed by...
Novel BRCA1-PLK1-CIP2A axis orchestrates homologous recombination-mediated DNA repair to maintain chromosome integrity during oocyte meiosis
Double-strand breaks (DSBs) are a formidable threat to genome integrity, potentially leading to cancer and various genetic diseases. The prolonged lifespan of mammalian oocytes increases their susceptibility to DNA damage over time. While somatic cells suppress DSB repair during mitosis, oocytes exhibit a remarkable capacity to repair DSBs during meiotic maturation. However, the precise mechanisms underlying DSB repair in oocytes remain poorly understood. Here, we describe the pivotal role of...
Challenges for aging research in Lebanon in times of crisis and conflict
No abstract
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. Here, we established aging- and senescence-related plasma...
Associations between dietary carotenoid and biological age acceleration: insights from NHANES 2009-2018
Carotenoids are naturally occurring pigments found in plants and certain microorganisms. Some carotenoids act as precursors to vitamin A, which is essential for various health aspects, including vision, immune function, and skin health. Carotenoids, including α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein and zeaxanthin, are known to reduce the risk of age-related diseases and promote healthy aging. This study examines the relationship between dietary carotenoid levels and biological...
Circulating small extracellular vesicles as blood-based biomarkers of muscle health in aging nonhuman primates
Age-associated loss of muscle mass and function and subsequent mobility decline define poor health outcomes, reduced quality of life, and mortality risk. The rate and extent of aging-related muscle loss varies across older adults. It is challenging to understand the molecular pathogenesis of mobility decline, as anthropometric and imaging techniques, primarily used in muscle function assessment, do not offer much molecular information. Small extracellular vesicles (sEV) are lipid membrane-bound,...
A multi-stage feature selection method to improve classification of potential super-agers and cognitive decliners using structural brain MRI data-a UK biobank study
Cognitive aging is described as the age-related decline in areas such as memory, executive function, reasoning, and processing speed. Super-Agers, adults over 80 years old, have cognitive function performance comparable to middle-aged adults. To improve cognitive reserve and potentially decrease Alzheimer's disease (AD) risk, it is essential to contrast changes in regional brain volumes between "Positive-Agers" who have superior cognitive performance compared to their age peers but are not 80...
Effects and mechanisms of APP and its cleavage product Aβ in the comorbidity of sarcopenia and Alzheimer's disease
Sarcopenia and AD are both classic degenerative diseases, and there is growing epidemiological evidence of their comorbidity with aging; however, the mechanisms underlying the biology of their commonality have not yet been thoroughly investigated. APP is a membrane protein that is expressed in tissues and is expressed not only in the nervous system but also in the NMJ and muscle. Deposition of its proteolytic cleavage product, Aβ, has been described as a central component of AD pathogenesis....
Scientists fear big cuts to animal research under Trump 2.0
New political environment could provide opening for groups that want to eliminate animal studies