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Effects of Physical Activity on Brain White Matter Integrity Are Region-, Dose-, and Age-Dependent: Findings From the Population-Based Rhineland Study

2 weeks ago
White matter integrity is a sensitive marker of cerebrovascular health and aging. Physical activity may promote white matter health, but previous studies were limited by self-reported activity and small sample sizes. We examined the association between accelerometer-based physical activity and novel indices of white matter integrity while identifying potential mediators. We analyzed cross-sectional baseline data from 4188 participants (58% women, mean age: 55.4 years) of the Rhineland Study, a...
Eva Saxler

Submillennial timescales of eruptible rhyolite magma: Converging evidence from Aira Caldera, Japan

2 weeks ago
Recent studies debate whether caldera-forming silicic magma is primarily stored in a crystal-poor, eruptible state for >100,000 years (kyr) ("warm storage") or exists as a crystal-rich "mush" with defrosting events causing brief periods (<1 kyr) of eruptibility ("cold storage"). To address this, we examined Aira Caldera (Japan), where the 400-cubic kilometer Aira-Tanzawa (AT) eruption (30,000 years ago) was preceded by three smaller eruptions over 3.5 kyr. All eruptions consist of roughly...
Bradley W Pitcher

Ly6d expression delineates two putative postnatal thymus epithelial progenitor cells that are differentially affected by aging

2 weeks ago
To date, the identity and maintenance of postnatal thymic epithelial progenitor cells (TEPCs) remain unclear, as does the persistence of bipotent TEPCs after birth or whether lineage-restricted progenitors independently maintain separate TEC compartments. Using an inducible lineage-tracing system based on expression of the thymoproteasomal protein β5t, which is expressed in embryonic and a subset of postnatal TEPCs, we explored the early dynamics of the relationships between thymic epithelial...
Irene Calvo-Asensio

Prolonged Oxidative Stress Drives p53/p21-Mediated Senescence and Degenerative Adaptation in Kidney-Derived Cells

2 weeks ago
Chronic oxidative stress has long been implicated in renal pathologies, but whether sustained oxidative damage primarily promotes chronic kidney disease (CKD) or tumorigenesis remains unclear. To address this question, we investigated the long-term effects of oxidative stress on human embryonic kidney (HEK293T) cells chronically exposed to a low dose of hydrogen peroxide (H(2)O(2), 50 μM H(2)O(2)) for 9 months, generating two adapted lines, 50R30 and 50R45. These cells exhibited enhanced...
Napat Armartmuntree

SIRT1 in brain aging: molecular mechanisms and therapeutic potential of pharmacological and natural modulators

2 weeks ago
Aging is a multifactorial process affects different tissues and organs and is modulated by genetic and environmental factors. In aging, the frequency of DNA repair errors and genomic instability are augmented. Depletion of endogenous antioxidant capacity during aging promotes the development of oxidative stress which triggers oxidative stress-induced DNA injury. Brain aging is manifested by cognitive impairment and memory disorders. Development of neuronal senescence is the major pathway in the...
Esraa M Mosalam

Identification and phenotypic profiling of subgroups with distinct cognitive aging trajectories

2 weeks ago
Cognitive aging is shaped by genetic variation, environmental factors, and health-related conditions. Until now, it is largely unclear why some individuals maintain their cognitive function, and others show progressive cognitive decline. This study uncovered determinants of distinct cognitive aging trajectories in the older population. To approach the inter-individual variability in cognitive aging, we clustered n = 696 dementia-free individuals from the prospective TREND study based on their...
Lydia M Federmann

Aging is associated with altered estrogen receptor expression and alters redox protein balance in human female skeletal muscle

2 weeks ago
It has been hypothesized that age‑related declines in skeletal muscle and vascular function in females may be partly estrogen‑dependent. This study investigated skeletal muscle protein expression of estrogen receptor α (ERα), estrogen receptor β (ERβ), and G protein-coupled estrogen receptor 1 (GPER1), and their association with proteins involved in redox regulation and vascular function, in relation to age, menopausal status, and lifelong physical activity. Skeletal muscle biopsies were...
Andrea Tamariz-Ellemann

Distinct amyloid-β filament fold in individuals with APP Flemish mutation

2 weeks ago
The dominantly inherited Flemish mutation-an A692G substitution in the amyloid precursor protein, corresponding to an A21G change in amyloid-β (Aβ)-causes a rare, early-onset form of Alzheimer disease characterized by pronounced cerebral amyloid angiopathy and unusually large senile plaque cores. Here, we report cryo-electron microscopy structures of amyloid filaments extracted from the postmortem parietal lobes of two individuals representing the only two known Flemish pedigrees worldwide....
Peerzada Shariq Shaheen Khaki

Stromal cell senescence augments haematopoietic cell fitness in clonal haematopoiesis

2 weeks ago
Microenvironment remodelling impacts tumour growth and metastasis, but whether remodelling promotes pre-malignant clonal fitness remains unknown. Here, using single-cell RNA-sequencing of the bone-marrow microenvironment in a mouse model of DNMT3A-mutant clonal haematopoiesis (CH), we identify mesenchymal stromal cells (MSCs) in a molecular state of cellular senescence. Elevated bone-marrow MSC senescence is also observed in humans with CH driven by several common somatic mutations. MSC...
Jayna J Mistry

Haemolytic injury and cardiovascular disease

2 weeks ago
Haemoglobin is a ferrous iron (Fe^(2+))-containing intracellular protein that is crucial for multiple homeostatic functions, including transport of oxygen and carbon dioxide, acid-base buffering and cellular signalling through nitric oxide oxidation and nitrite reduction. When erythrocyte membranes are disrupted, a process known as haemolysis that is caused by either disease or an exogenous stressor, haemoglobin is liberated into the plasma. This plasma free haemoglobin is highly pathogenic,...
Mark C Hieromnimon

Wearable ultrasound patch boosts REM sleep without drugs or surgery

2 weeks ago
A new wearable patch may help people reach REM sleep faster and remain there longer without medication or surgery. In a study of 28 participants, the device shortened the time to REM by 43 minutes and extended it by about 16 minutes. Researchers also observed signs of improved stress regulation and changes in brain circuits tied to emotion.