Exosomal miR-320e through wnt2targeted inhibition of the Wnt/ß-catenin pathway allevisate cerebral small vessel disease and cognitive impairment.

BACKGROUND: Exosomal miRNAs play crucial roles in many central nervous system diseases. Cerebral small vessel disease (CVSD) is a small vessel disease that is affected by various factors. This study aimed to investigate the role of exosomal miR-320e in the Wnt/ß-catenin pathway stimulated by oxidative stress and assess its clinical correlation with psychiatric symptoms in patients with CVSD. AIM: To explore whether exosomal miR-320e could suppress the Wnt/ß-catenin pathway and play a protective role in CVSD progression, as well as examine its potential correlation with cognitive impairment and depression in patients with CVSD. METHODS: Differentially expressed exosomal miRNAs were filtered by sequencing plasma exosomes from patients with CVSD and healthy controls. Bioinformatics and dual luciferase analyses were used to confirm the binding of miR-320e to Wnt2, and the mRNA and protein levels of downstream components in the Wnt/ß-catenin pathway were evaluated when overexpressed or with knockdown of miR-320e under H2O2-induced oxidative stress. In addition, Wnt2-targeting siRNA was used to confirm the role of miR-320e in the Wnt2-mediated inhibition of the Wnt/ß-catenin pathway. A retrospective analysis was conducted among patients with CVSD to confirm the correlation between miR-320e expression and the severity of cognitive impairment and depression, which were quantified using the Montreal Cognitive Assessment (MoCA)/Executive Function Assessment (EFA), and the Hamilton Depression Scale (HAMD)/Beck Depression Inventory (BDI), respectively. RESULTS: High-throughput sequencing revealed that exosomal miR-320e was downregulated in patients with CVSD. Bioinformatics analysis and dual-luciferase reporter gene experiments showed that exosomal miR-320e inhibited the Wnt/ß-catenin pathway in response to oxidative stress by targeting the 3' noncoding region of Wnt2. Uptake of exosomes carrying miR-320e into endothelial cells could also target Wnt2 and inhibit the Wnt2/ß-catenin pathway. Elevated miR-320e expression may protect patients with CVSD from relatively severe cognitive impairment and depression, as it was found to have a positive correlation with the MoCA/EFA and HAMD/BDI scores. CONCLUSION: Our results suggest that exosomal miR-320e suppresses the Wnt/ß-catenin pathway and may play a protective role in CVSD progression.

Associations of CXCL16, miR­146a and miR­146b in atherosclerotic apolipoprotein E­knockout mice.

Atherosclerosis is the primary cause of cardiovascular and cerebrovascular diseases. Recent studies have revealed that C­X­C motif chemokine ligand 16 (CXCL16), microRNA (miR)­146a and miR­146b may have important roles in atherosclerotic diseases. However, the associations of CXCL16, miR­146a and miR­146b in atherosclerotic diseases in vivo remain unclear. Previous studies have demonstrated that miR­146a and miR­146b may negatively regulate the toll like receptor (TLR4)/nuclear factor (NF)­κB signaling pathway to repress the inflammatory response. The present study investigated the associations of CXCL16, miR­146a and miR­146b in atherosclerotic apolipoprotein E (ApoE)­/­ mice in vivo. The expression levels of CXCL16, TLR4/NF­κB signaling pathway, miR­146a and miR­146b in the control and atherosclerotic ApoE­/­ mice were investigated via reverse transcription­quantitative polymerase chain reaction and western blot analysis. The present study demonstrated that the expression of CXCL16 was significantly upregulated in atherosclerotic ApoE­/­ mice compared with control ApoE­/­ mice. The expression levels of TRL4, interleukin­1 receptor­associated kinase 1, tumor necrosis factor receptor associated factor 6, NF­κB, tumor necrosis factor­α and interleukin­1ß were also significantly upregulated in atherosclerotic ApoE­/­ mice compared with control mice. However, the present study revealed that the expression levels of miR­146a and miR­146b were significantly downregulated in atherosclerotic ApoE­/­ mice compared with control ApoE­/­ mice. Overall, the results of the present study suggested that CXCL16 may regulate the TRL4/NF­κB/CXCL16 signaling pathway, and that miR­146a and miR­146b may negatively regulate CXCL16 via this pathway in atherosclerosis in vivo.