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Alzheimer's disease (AD) progresses along a continuum for years to possibly decades prior to cognitive decline. Although AD is primarily an age-related brain pathology, increasing evidence indicates dysfunction in peripheral nerves and skeletal muscle may manifest early in the disease progression. However, the underlying cause(s) for peripheral nerve dysfunction leading to impaired skeletal muscle torque production are not understood. Sciatic nerves from 5xFAD and wild-type (WT) mice were...

CONCLUSIONS: In the multimorbidity management model for older adults, interventions such as patient peer support groups and case manager-led health education are proposed as theoretical strategies. These potential measures aim to support patient self-efficacy and facilitate health literacy, thereby potentially contributing to better overall health of patients.

CONCLUSIONS: There are distinct joint trajectories of physical frailty and social relationships among Japanese community-dwelling older adults. These trajectories are associated with different risks of long-term care needs, with the progressive frailty and rapid social relationships decline subgroup facing the greatest burden.

Macrophages are pivotal immune cells due to their phagocytic capabilities, yet the impact of aging on macrophage phagocytosis remains poorly understood. Using comprehensive in vitro and in vivo phagocytic assays, we demonstrate significantly reduced phagocytic activity in monocyte-derived macrophages from aged humans and mice compared to young counterparts. RNA-seq analysis revealed upregulated expression of extracellular matrix protein genes, particularly collagens, in aged macrophages;...

Myofibroblasts are morphologically similar cells with diverse origins that exhibit characteristics of both fibroblasts and smooth muscle cells. Following insults, myofibroblasts play critical roles in tissue reintegration and restitution. However, their prolonged presence and activity impede physiological recovery, leading to persistent or progressive tissue complications, as evidenced in corneal fibrosis and opacification. Reactive oxygen species (ROS) are key signaling intermediates in various...

For years, calcium and vitamin D supplements have been promoted as a simple way for older adults to protect their bones and prevent falls. But a massive review of nearly 154,000 people found that calcium, vitamin D, or a combination of both provided little to no meaningful protection against fractures or falls for most older adults.

A large-scale study suggests that men with higher levels of the amino acid tyrosine may have shorter lifespans, potentially losing close to a year of life expectancy. The finding is especially intriguing because tyrosine is commonly associated with brain health and is often used in supplements aimed at boosting focus and performance.

Quantitative insights into brain metabolism are essential for advancing our understanding of the energy dynamics in the brain. Here, we present a nanowatt-resolution biocalorimeter capable of real-time metabolic heat output measurements of individual, live Drosophila melanogaster brains. Using this platform, we show that female brains, across multiple genotypes, exhibit a significantly higher metabolic rate (∼10%-15%) than male brains at a young age (<10 days old) and follow distinct metabolic...

Freezing of gait (FOG) is a debilitating symptom of Parkinson's disease (PD) that has been related to abnormal functional connectivity across motor, cognitive, and limbic networks. However, it remains unclear how directional (i.e., effective) connectivity between various networks is altered by an actual FOG-related motor imagery task. Twenty-four individuals with PD (11 freezers and 13 non-freezers) and 15 healthy controls underwent functional MRI. Participants performed a motor imagery task...

Parkinson's disease leads to a spectrum of locomotor deficits that vary in severity with the nature of daily activities and the fluctuating physiology of patients. Many of these deficits remain inadequately addressed by existing deep brain stimulation therapies that rely on activity-agnostic parameters optimized for cardinal motor symptoms. By contrast, therapies embedding activity-specific parameters have the potential to better address the entire range of symptoms. Here we expose physiological...

A randomized crossover study of five patients with Parkinson's disease (PD) demonstrates that gait-synchronized adaptive deep brain stimulation is feasible and safe, and reduces falls compared with continuous stimulation. Gait dysfunction in PD is a major source of disability and is often insufficiently treated by continuous deep brain stimulation (cDBS). Although adaptive DBS (aDBS) has shown efficacy for other motor symptoms using β-based, state-driven neural signals, gait is a dynamic,...

Aging is asynchronous across cells and organs. Here we tested whether plasma proteomics can be used to analyze cell type-specific aging. From analyses of over 7,000 plasma proteins measured in 60,542 individuals, we developed machine learning models to estimate the biological age of over 40 cell types spanning neuronal, immune, glial, endocrine, epithelial and musculoskeletal origins. We observed that 20-25% of individuals exhibited accelerated aging in a single cell type and 1-3% in 10 or more...

No abstract

Aging tissues experience a gradual decline in perfusion and metabolic resilience due to complex interactions among extracellular matrix (ECM) remodeling, vascular dysfunction, and mitochondrial impairment. Stiffening of the ECM that results from collagen crosslinking, elastin loss, and basement membrane thickening reduces vascular compliance and impairs local angiogenesis. The consequent reduction in capillaries and diminished endothelial reactivity leads to ongoing or intermittent hypoxia,...

Quantitative insights into brain metabolism are essential for advancing our understanding of the energy dynamics in the brain. Here, we present a nanowatt-resolution biocalorimeter capable of real-time metabolic heat output measurements of individual, live Drosophila melanogaster brains. Using this platform, we show that female brains, across multiple genotypes, exhibit a significantly higher metabolic rate (∼10%-15%) than male brains at a young age (<10 days old) and follow distinct metabolic...