1,2-Diacetylbenzene impaired hippocampal memory by activating proinflammatory cytokines and upregulating the prolactin pathway: An in vivo and in vitro study

Memory loss is the most common occurrence of dementia in the elderly population. Evidence shows 1,2-Diacetylbenzene (DAB) can exacerbate cerebral dysfunction. The molecular mechanisms involved in DAB actions in the hippocampus have not been well elucidated to date. qPCR, western blot, Morris water maze, and RNAseq analysis were used to identify the association between inflammation and hyperphosphorylated tau in male DABtreated mice (1 or 5 mg/kg/day), rats (3 mg/kg/day), in vitro BV2 microglial cells (1 or 5 mu M), and the hippocampal transcriptome of male DAB-treated rats. We found that DAB induces memory deficits by activating proinflammatory cytokines as well as down-regulating memory and learning genes. Several genes involved in learning, memory, and behavior induced by DAB (e.g., PRL, Pit-1, PRLR, Ttr, Notch2, Ntsr1, C5ar2, Cd74) were not changed or downregulated in young rats, but upregulated in old rats. Detoxification pathways were upregulated in young rats treated with DAB, whereas prolactin (PRL) signaling pathways were upregulated in old DAB-treated rats. Further work is needed to gain a better understanding of the roles of PRL during aging.