Running out the clock: Circadian rhythm dysfunction in cognitive disease.

Abstract

Lifespan is increasing such that within a few decades approximately twenty percent of the world's population is expected to be greater than sixty years of age. In concert with global aging of the population, neurodegenerative disorders have become the leading cause of disability with dementia now the seventh leading cause of death worldwide. Despite multi-faceted treatment approaches for disorders of cognition that include Alzheimer's disease and multiple sclerosis, present therapies ultimately cannot halt disease progression and eventually cognitive impairment continues unabated. Furthermore, co-morbidities, such as metabolic disorders with diabetes mellitus, also lack strategies to prevent disease progression. Given these clinical challenges for cognitive loss, innovative avenues of investigation that involve mammalian chronobiology with circadian rhythm clock genes and related pathways of aging, cellular senescence, oxidative stress, metabolic dysfunction, sleep fragmentation, apolipoprotein E, programmed cell death, silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae), nicotinamide adenine dinucleotide, the gut microbiota, and glucagon-like peptide-1 receptor agonism may offer exceptional promise for forging new strategies for cognitive disease treatment. These pathways are intimately linked to circadian rhythm processes, are complex in generating biological outcomes, can broadly influence clinical translation of both short- and long-term considerations for cognitive disease care, and necessitate dissection of their precise regulatory mechanisms with the benefit from early diagnostic platforms as well as artificial intelligence and machine learning applications to foster translation of these pathways into effective clinical treatments.