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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...

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...

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...

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...

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....

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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...

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,...

CONCLUSION: The current evidence does not establish a definitive APOE ε4-specific preventive effect of PA. Future studies may be most informative if they target earlier-stage, low-active, or metabolically at-risk APOE ε4 carriers using objective PA measures and proximal vascular, metabolic, imaging, or blood-based biomarker outcomes.

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.

Beginning around age 50, the brain’s memory center appears to lose many of its longtime immune cells and replace them with more inflammatory ones. This surprising shift may help explain how normal aging sets the stage for Alzheimer’s disease and dementia.

Study of mitochondria suggests new treatment strategy for Alzheimer’s and other diseases

A long-term brain study found that common risks such as smoking, high blood pressure, heart disease, and high blood lipids were strongly linked to damage associated with vascular dementia. The findings suggest that healthier lifestyle choices could help delay dementia by reducing several harmful brain changes at once.

Hyperphosphorylation and aggregation of tau are pathological hallmarks of tauopathies. Mitochondrial dysfunction is also a common feature of tauopathies. The mechanistic link between tau abnormalities and mitochondrial dysfunction and its relationship to the physiological function of tau, however, is unclear. Here, we demonstrate that tau regulates mitochondrial reverse electron transport (RET), which produces excess reactive oxygen species (ROS), reduces the NAD^(+)/NADH ratio, and is activated...

Alzheimer's disease (AD) is a slow-progressing neurodegenerative disease, mainly characterized by the accumulation of amyloid beta (Aβ) plaques and intracellular hyperphosphorylated Tau protein, along with the generation of free radicals. In normal physiology free radicals play a promising role. However, the imbalance in the formation and clearance of the free radicals or reactive oxygen species/reactive nitrogen species (ROS/RNS) disrupts redox homeostasis, resulting in oxidative stress....

The primary mechanism and subcellular localisation of α-synuclein toxicity in Parkinson's disease pathogenesis remain unknown. We spatially and temporally resolved proteomic and transcriptomic changes in human iPSC-derived dopaminergic neurons with increasing burden of pathological α-synuclein. We found that misfolded α-synuclein proteoforms, signified by the formation of nanoscale intraneuronal puncta, are associated with impaired translocon function at the endoplasmic reticulum (ER). We show...

Classical evolutionary theories of aging, including antagonistic pleiotropy (AP) and the disposable soma theory (DST), explain why aging exists but are often applied without considering how sex-specific reproductive strategies shape the forces of natural selection on survival. They do not explain why females consistently outlive males across taxa, despite their greater reproductive investment, or why in some contexts, such as eusocial queens, extraordinary fecundity is coupled with exceptional...