HMOX1 and Cognitive impairment: Based on these promising findings, the present study is aimed at evaluating the effects of MSCs-Exo in model of dNCR and at determining if MSCs-Exo ameliorate cognitive impairment by inhibiting ferroptosis via activating SIRT1/Nrf2/HO-1 pathway, as well as provide potential theoretical and experimental evidence for the treatments of dNCR patients, identifying potential therapeutic targets for clinical treatment.