Fig. 6

Overexpression of miR-3968 or silencing UBE2K rescues synaptic and memory impairments in AD mice. Lentivirus containing miR-3968 or shUBE2K was injected into the bilateral hippocampi of 5-month-old APP/PS1 mice. Four weeks later, the mice underwent NOR and MWM, and then were sacrificed for WB and Golgi staining. The experimental groups were as follows: W—WT mice, A—APP/PS1 mice, M—APP/PS1 mice injected with miR-3968 lentivirus, U—APP/PS1 mice injected with shUBE2K lentivirus. a, b Performance in the MWM test. Latency during learning stage was recorded (a). The representative traces (a) and crossing times (b) on day 7 were analyzed. The study was conducted on 15 WT mice, 12 APP/PS1 mice, 13 APP/PS1 mice injected with miR-3968 lentivirus, and 13 APP/PS1 mice injected with shUBE2K lentivirus. Data were analyzed with one-way ANOVA with LSD post-hoc test. c Recognition memory was tested using the NOR. Data were analyzed with one-way ANOVA with LSD post-hoc test. d–f Golgi-cox staining was performed to demonstrate spine density and maturation. d Representative images of dendritic spines. Scale bar, 2.5 μm. e Quantitative analysis of spine density and f the percentage of mushroom-type spines are presented. The data were obtained from 20 neurons per group (one-way ANOVA with Tukey’s post-hoc test). g–i Dendritic morphology of neurons was analyzed using Golgi staining. g Representative images of dendritic trees are shown, with a scale bar of 25 μm. Sholl analysis (h) and DCI analysis (i) were performed to evaluate dendritic complexity. j Protein levels of UBE2K, GluN2B, SYN1, SYP, and PSD95 were measured in hippocampal homogenates from four different groups using WB (left). Quantitative analysis was performed on data obtained from three samples in each group (right). k qRT-PCR analysis was performed to detect circRIMS2, miR-3968, and UBE2K in hippocampal homogenates from four different groups (n = 4). Data are presented as mean ± SEM and two-tailed t tests were used unless otherwise specified. *P < 0.05, **P < 0.01, ***P < 0.001 vs W; ^#P < 0.05, ^##P < 0.01, ^###P < 0.001 vs A