Neuroprotective effects of Canagliflozin: lessons from aged genetically diverse UM-HET3 mice

Abstract

The aging brain is characterized by a progressive increase in neuroinflammation and central insulin resistance, which contribute to neurodegenerative diseases and cognitive impairment. Recently, the Interventions Testing Program (ITP) demonstrated that the anti-diabetes drug, Canagliflozin (Cana), a sodium-glucose transporter 2 inhibitor (SGLT2i), led to lower fasting glucose and improved glucose tolerance in both sexes, but extended median lifespan by 14% only in male mice. Here we show that Cana treatment significantly improved central insulin sensitivity in the hypothalamus and the hippocampus of 30-month-old male mice. Remarkably, Cana-treated mice showed significant reductions in age-associated hypothalamic gliosis with a decrease in inflammatory cytokine production by microglia in both sexes. In the hippocampus, Cana reduced microgliosis and astrogliosis in males, but not in female mice. The decrease in microgliosis was partially dependent on mTOR signaling, as evidenced by reduced phosphorylation of S6 kinase in microglia of Cana-treated aged male, but not female mice. Remarkably, Cana treatment improved exploratory and locomotor activity of 30-month-old male but not female mice. Taken together, our findings demonstrate sex-specific neuroprotective effects of Cana treatment, suggesting its application for the potential treatment of neurodegenerative diseases.