Changes in the expression of countless genes takes place with aging. Some of these changes are adaptive, attempts to resist the damaged environment or compensate for other impaired functions. Many are maladaptive and actively cause harm. Researchers here identify a specific maladaptive change in expression in neurons in the brains of aged mice, an increase in FTL1 that appears to produce a range of harm that contributes to loss of cognitive function.
Understanding cellular and molecular drivers of age-related cognitive decline is necessary to identify targets to restore cognition at old age. Here we identify ferritin light chain 1 (FTL1), an iron-associated protein, as a pro-aging neuronal factor that impairs cognition. Using transcriptomic and mass spectrometry approaches, we detect an increase in neuronal FTL1 in the hippocampus of aged mice, the levels of which correlate with cognitive decline.
Mimicking an age-related increase in neuronal FTL1 in young mice alters labile iron oxidation states and promotes synaptic and cognitive features of hippocampal aging. Targeting neuronal FTL1 in the hippocampi of aged mice improves synaptic-related molecular changes and cognitive impairments. Using neuronal nuclei RNA sequencing, we detect changes in metabolic processes, such as ATP synthesis, and boosting these metabolic functions through NADH supplementation mitigated pro-aging effects of neuronal FTL1 on cognition. Our data identify neuronal FTL1 as a key molecular mediator of cognitive rejuvenation.
