Systemic delivery of liposome-loaded microRNA-195 ameliorates spatial memory impairment in a rat model of chronic cerebral hypoperfusion.

Chronic cerebral hypoperfusion (CCH), a subclinical state underlying mild cognitive impairment (MCI), triggers multiple pathological changes associated with Alzheimer's disease (AD) and vascular dementia (VaD), including amyloid-β (Aβ) deposition, tau phosphorylation, microglial activation and neural circuit dysfunction. Developing multitarget therapeutics to effectively prevent the transition from MCI to AD and/or VaD remains an urgent challenge. Herein, we engineered a brain-targeted dual-modified PEGylated nanoliposome (LipTM@miR-195), incorporating mannose (MAN) and the trans-activating protein of HIV type 1 (TAT), which encapsulates polyethyleneimine (PEI) complesed microRNA-195 (miR-195). In a CCH rat model, tail-vein administration of LipTM@miR-195 (0.112 mg/kg) efficiently crossed the blood-brain barrier (BBB) without detectable side effects. Treatment reversed CCH-induced spatial learning and memory deficits, rescued neural circuit dysfunction, and suppressed elevated APP, BACE1, AT8 and CD68 levels. Collectively, these findings provide compelling evidence that LipTM@miR-195 nanoliposome holds therapeutic potential for CCH-induced cognitive impairment, thereby preventing the progression from MCI to AD and/or VaD.