NATURE: Why is blood-brain transport impaired with age?

The brain'sblood vesselsinterface, known as the Blood-Brain Barrier (BBB), and studies have shown that some of them maintain brain function through low transcellular permeabilityHowever, recent studies have shown that the aging brain is sensitive to circulating proteinsTherefore, it is not clear whether the permeability of the individual injection of exogenous tracers (standard BBB research methods) fully represents the transport of blood to the brainIn a recent study, researchers tagged hundreds of protein-made mouse plasma protein groups and injected them into mice to study the role of BBB and its physiological ligandresearchers have found that plasma proteins can easily penetrate into healthy brain essence and are transported by BBB-specific transcription proceduresUnlike IgG antibodies, the decline in plasma protein intake in the elderly brain is driven by age-related transport transitions: transport from ligand-specific receptor-mediated transport to nonspecific cystic cell swallowing transportthis age-related transition coincides with a loss of specific cell membrane coveragePharmacological lysopase ALPL (a predicted negative regulator) that inhibits age-altering increases enhances the brain's intake of treatment-related transfidelatec, ferritin receptor antibodies, and plasmathese findings reveal the extent to which physiological proteins in the healthy brain are transported, as well as a mechanism for BBB dysfunction that is widespread with age, a strategy to enhance drug delivery