Thirteen proteins linked to brain aging in humans are identified in a Nature Aging paper. Changes in the concentrations of these blood proteins may peak at 57, 70, and 78 years old in humans, and suggest that these ages may be important for potential interventions in the brain aging process.

It is estimated that by 2050 the number of individuals aged 65 years and over will exceed 1.5 billion globally, highlighting the need for a deeper understanding of the aging process—particularly in relation to the brain.

The prevalence of neurodegenerative disorders, such as dementia, is known to increase with aging; however, effective therapies are still limited. The early identification of and intervention in brain aging could help us to prevent such disorders.

Summary: Research reveals that people with high blood pressure who also sleep less than six hours per night face increased risks of brain injury, accelerated brain aging, and impaired executive function. The study assessed 682 participants from the Framingham Heart Study, analyzing sleep patterns, blood pressure, cognitive performance, and brain MRIs.

These risks were not present in individuals with normal blood pressure, highlighting a concerning interaction between sleep deprivation and hypertension. Researchers suggest treating sleep problems and hypertension as potential interventions to protect brain health and delay cognitive decline.

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📚 🔗 https://brnw.ch/21wPhFj.

🧑🏻‍🔬 By Ms. Cloe García Porta, Dr. Kashif Mahfooz, Mr. Joanna Komorowska, Dr. Sara Garcia-Rates and Dr. Susan Greenfield.

During development, a 14mer peptide, T14, modulates cell growth via the α-7 nicotinic acetylcholine receptor (α7 nAChR). However, this process could become excitotoxic in the context of the adult brain, leading to pathologies such as Alzheimer’s disease (AD). Recent work shows that T14 acts selectively via the mammalian target of rapamycin complex 1 (mTORC1). This pathway is essential for normal development but is overactive in AD. The triggering of mTORC1 has also been associated with the suppression of autophagy, commonly observed in ageing and neurodegeneration. We therefore investigated the relationship between T14 and autophagic flux in tissue cultures, mouse brain slices, and human Alzheimer’s disease hippocampus.

Chaperone-mediated autophagy (CMA) is the lysosomal degradation of individually selected proteins, independent of vesicle fusion. CMA is a central part of the proteostasis network in vertebrate cells. However, CMA is also a negative regulator of anabolism, and it degrades enzymes required for glycolysis, de novo lipogenesis, and translation at the cytoplasmic ribosome. Recently, CMA has gained attention as a possible modulator of rodent aging. Two mechanistic models have been proposed to explain the relationship between CMA and aging in mice. Both of these models are backed by experimental data, and they are not mutually exclusionary. Model 1, the “Longevity Model,” states that lifespan-extending interventions that decrease signaling through the INS/IGF1 signaling axis also increase CMA, which degrades (and thereby reduces the abundance of) several proteins that negatively regulate vertebrate lifespan, such as MYC, NLRP3, ACLY, and ACSS2. Therefore, enhanced CMA, in early and midlife, is hypothesized to slow the aging process. Model 2, the “Aging Model,” states that changes in lysosomal membrane dynamics with age lead to age-related losses in the essential CMA component LAMP2A, which in turn reduces CMA, contributes to age-related proteostasis collapse, and leads to overaccumulation of proteins that contribute to age-related diseases, such as Alzheimer’s disease, Parkinson’s disease, cancer, atherosclerosis, and sterile inflammation. The objective of this review paper is to comprehensively describe the data in support of both of these explanatory models, and to discuss the strengths and limitations of each.

Chaperone-mediated autophagy (CMA) is a highly selective form of lysosomal proteolysis, where proteins bearing consensus motifs are individually selected for lysosomal degradation (Dice, 1990; Cuervo and Dice, 1996; Cuervo et al., 1997). CMA is mechanistically distinct from macroautophagy and microautophagy, which, along with CMA, are present in most mammalian cells types.

Macroautophagy (Figure 1 A) begins when inclusion membranes (phagophores) engulf large swaths of cytoplasm or organelles, and then seal to form double-membrane autophagosomes. Autophagosomes then fuse with lysosomes, delivering their contents for degradation by lysosomal hydrolases (Galluzzi et al., 2017). Macroautophagy was the first branch of autophagy to be discovered, and it is easily recognized in electron micrograms, based on the morphology of phagophores, autophagosomes, and lysosomes (Galluzzi et al., 2017).