Remote ischemic conditioning alleviates chronic cerebral hypoperfusion-induced cognitive decline and synaptic dysfunction via the miR-218a-5p/SHANK2 pathway

• Published in: Progress in neurobiology Vol. 230; p. 102514
• Main Authors: Li, Ning, Ren, Changhong, Li, Sijie, Yu, Wantong, Jin, Kunlin, Ji, Xuming
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.11.2023
• Subjects: Chronic cerebral hypoperfusion; miR-218a-5p; Remote ischemic conditioning; SHANK2; Synaptic function; Vascular cognitive impairment; HH; fEPSPs; Remote ischemic conditioning; LTP; p-GluR1; cSVD; CA1; SHANK, CCH; RNA-seq; miR-218a-5p; MWM; GluR2; 2VO; RIC; NR2B; PSD95; GluR1; Vascular cognitive impairment; AAV; GluT1; NR2A; Synaptic function; SHANK; Chronic cerebral hypoperfusion; HC; LTD; VCI; SHANK2; vascular cognitive impairment; remote ischemic conditioning; synaptic function
• ISSN: 0301-0082; 1873-5118
• DOI: 10.1016/j.pneurobio.2023.102514

Vascular cognitive impairment (VCI) due to chronic cerebral hypoperfusion (CCH), is the second leading cause of dementia. Although synaptic impairment plays a critical role in VCI, its exact mechanism remains unknown. Our previous research revealed that remote ischemic conditioning (RIC) could alleviate cognitive decline resulting from CCH, however, its effects on synaptic impairment remain unclear. In this study, we confirmed that RIC alleviated both cognitive decline and its associated synaptic dysfunction caused by CCH. RNA sequencing revealed that CCH increased in miR-218a-5p expression, which was decreased by RIC. Elevated miR-218a-5p levels limited the benefits of RIC, however, inhibiting miR-218a-5p in hippocampal CA1 neurons rescued synaptic dysfunction. Additionally, we found that SHANK2 is a downstream target of miR-218a-5p, and inhibiting SHANK2 expression reduced the alleviation caused by hypoxic conditioning in synaptic impairment in vitro. In conclusion, our results suggested that RIC alleviated synaptic impairment via the miR-218a-5p/SHANK2 pathway, which could be a potential biomarker or therapeutic target for cognitive impairment caused by CCH. [Display omitted] •RIC rescues cognitive decline caused by CCH by alleviating synaptic dysfunction.•miR-218a-5p regulates the alleviation of synaptic dysfunction induced by CCH through RIC.•SHANK2 is a downstream target of miR-218a-5p involved in RIC regulation in 2VO rats.