Aggregator

Scientists have uncovered a hidden mechanism that allows high-cholesterol diets to undermine the body's natural cholesterol defenses, and blocking it dramatically lowered harmful LDL cholesterol in mice. Even more promising, an experimental drug targeting this pathway has already passed an early human safety trial, potentially speeding the development of a new treatment for high cholesterol.

Scientists at Johns Hopkins have uncovered a crucial missing link between a common gut bacterium and colorectal cancer, solving a mystery that has puzzled researchers for nearly two decades. The bacterium, Bacteroides fragilis, produces a toxin that damages the colon’s protective lining, triggers chronic inflammation, and promotes tumor formation.

Scientists have discovered a bizarre bacterial defense system that works almost completely backward from anything seen before. Unlike typical bacterial immune systems that keep a deadly toxin under control until a virus attacks, this unusual mechanism waits until an infection begins before producing the DNA that switches on its lethal weapon. The infected bacterium then destroys itself, preventing the virus from multiplying and spreading to neighboring cells.

Gene transcription by RNA Polymerase II (Pol II) is highly vulnerable to transcription-blocking DNA lesions (TBLs), which, if unresolved, induce transcription stress leading to cellular decline and aging. TBLs are removed by transcription-coupled nucleotide excision repair (TC-NER). TC-NER is initiated when Cockayne syndrome group B protein recognizes lesion-stalled Pol II and promotes TC-NER complex assembly. This complex recruits TFIIH for lesion verification, followed by incision and repair...

As they age, older adults are increasingly susceptible to health decline associated with excessive alcohol consumption, which can accelerate biological aging through cellular stress, senescence-associated responses, and inflammaging. Although sesaminol, a sesame-derived lignan, protects against alcohol-induced colitis in young animals, its effects on alcohol-associated intestinal dysfunction and senescence-related changes in middle-aged animals remain unclear. In this study, middle-aged mice (50...

Circadian biology is recognized for its importance to physiology and metabolism, with implications for healthy aging and disease risk. To test whether altering the number of imposed environmental cycles experienced per unit chronological time affects health biomarkers and lifespan, we compressed and expanded the photic cycle (T-cycle, combined light:dark length) by ~ 10% relative to the 24-h day. Male C57BL/6 J mice (n = 60 per group, 12 weeks old) were randomized to one of three T-cycles: T ~...

Aging is a universal biological process signified by a time-dependent decline in physiological activity, driven by molecular and cellular damage, leading to greater susceptibility to diseases and fatal outcomes. Impaired proteostasis is a key aspect of cellular aging in which the cells become less efficient at folding, repairing, and recycling proteins, consequently inducing accumulation of damaged and aggregation-prone proteins. The onset of muscle loss is driven by a reduction in protein...

Quantifying biological aging and predicting age-related functional decline are increasingly important for reducing the health and socioeconomic burden of population aging. DNA methylation is one of the most extensively studied epigenetic features of aging and underlies epigenetic clocks, promising quantitative biomarkers of biological age. However, the molecular processes driving age-associated DNA methylation changes and the biological signals captured by these clocks remain unclear. A major...

Radiotherapy combined with immunotherapy has emerged as a promising therapeutic strategy across multiple cancer types. However, despite encouraging findings from selected clinical trials, most radioimmunotherapy studies have shown only limited or even negative results, highlighting important biological barriers that limit therapeutic efficacy. Accumulating evidence suggests that radiotherapy induces phenotypic and functional changes in immune cells that resemble key features of age-related...

Bone marrow macrophages (BMMs) coordinate skeletal remodelling, haematopoietic niche function, immune surveillance, and tissue repair. Whether a persistent senescent state in BMMs is a causal driver of skeletal ageing, however, remains unresolved. The central challenge is both definitional and causal: macrophages may be quiescent, terminally differentiated, chronically activated, tolerant, or metabolically dysfunctional, whereas commonly used senescence markers-including p16^(INK4a), p21^(CIP1),...

DNA-protein crosslinks (DPCs) are one of the most complex and deleterious forms of DNA damage. DPCs arise from the stabilization of covalent enzyme-DNA intermediates, such as topoisomerase cleavage complexes, or from exposure to bifunctional crosslinking agents, and they differ in protein identity, DNA context and chemical linkage. Because of their bulky nature, DPCs obstruct essential chromatin processes such as DNA replication and transcription, making their timely removal by dedicated DPC...

No abstract

Terrestrial ecosystems are changing rapidly under global nutrient enrichment, yet how canopy nutrients balance shapes the seasonal end of photosynthesis, a critical control on ecosystem carbon cycling, remains unclear. Rising anthropogenic nitrogen inputs are shifting many ecosystems towards relative phosphorus limitation, with uncertain consequences for autumn phenology. Here, we combined airborne imaging spectroscopy with remotely sensed phenology to test whether canopy nutrient ratios predict...

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and is promoted by atrial fibrosis, a form of structural remodelling for which effective therapies are lacking. MicroRNA-31-5p (miR-31-5p), an aging-associated, atrial-enriched microRNA, has been linked to AF, but its role in atrial fibrosis is unknown. Here we show that atrial fibroblasts from patients with persistent AF exhibit increased miR-31-5p expression and reduced expression of the calcitonin receptor (CTR, encoded...

Tree shrews are small mammals closely related to primates, which originate in Southeast Asia. In several aspects of their morphology and physiology, tree shrews more closely resemble humans than rodents. For example, the development of their visual system parallels that of humans, making them a desirable model species for pre-clinical research. Despite the use of tree shrews in research for over 50 years, little is known about the basic demography of tree shrews. No detailed lifespan studies are...

CONCLUSIONS: Adding modest dairy product intake to home-based resistance training did not provide additional overall benefits compared to exercise alone. However, exploratory findings suggest that baseline dairy consumption may influence the responsiveness of older adults to combined nutrition and exercise interventions.

CONCLUSION: Higher insulin resistance is a significant modifiable factor for cognitive impairment, specifically in women aged ≥65 years. These exploratory findings suggest potential sex-related differences in the metabolic-cognitive association, underscoring the importance of sex-specific metabolic management starting from midlife to help preserve cognitive health in later life.

Scientists at Johns Hopkins University have uncovered a surprising process that helps humans develop sharp vision before birth, challenging decades of assumptions about how the eye forms. Using miniature human retinas grown in the lab, researchers discovered that a vitamin A derivative and thyroid hormones work together to shape the foveola, the tiny region at the center of the retina responsible for our sharpest vision.

A major international study found that a simple blood test could help predict Alzheimer’s-related cognitive decline years before symptoms appear, with the highest-risk individuals facing a 38% chance of impairment within five years and an estimated 78% chance within 10 years. Scientists believe the discovery could pave the way for earlier intervention and future treatments designed to prevent Alzheimer’s before memory problems begin.

A promising new study suggests that more than half of younger adults with type 2 diabetes could achieve remission in just six months through a combination of a low-calorie diet and structured exercise. Researchers found that 54% of participants under age 45 who followed an intensive diet and exercise program achieved remission, compared with just 4% receiving usual care.