Exosomal miR-214-5p Released from Glioblastoma Cells Modulates Inflammatory Response of Microglia after Lipopolysaccharide Stimulation through Targeting CXCR5.

BACKGROUND AND OBJECTIVE: Exosomes communicate inter-cellularly and miRNAs play critical roles in this scenario. MiR-214-5p was implicated in multiple tumors with diverse functions uncovered. However, whether miR-214-5p is mechanistically involved in glioblastoma, especially via exosomal pathway, is still elusive. Here we sought to comprehensively address the critical role of exosomal miR-214-5p in glioblastoma (GBM) microenvironment. METHODS: The relative expression of miR-214-5p was determined by real-time PCR. Cell viability and migration were measured by MTT and transwell chamber assays, respectively. The secretory cytokines were measured with ELISA kits. The regulatory effect of miR-214-5p on CXCR5 expression was interrogated by luciferase reporter assay. Protein level was analyzed by Western blot. RESULTS: We demonstrated that miR-214-5p was aberrantly overexpressed in GBM and associated with poorer clinical prognosis. High level of miR-214-5p significantly contributed to cell proliferation and migration. GBM-derived exosomal miR-214-5p promoted inflammatory response in primary microglia upon lipopolysaccharide challenge. We further identified CXCR5 as the direct target of miR-214- 5p in this setting. CONCLUSION: Overexpression of miR-214-5p in GBM modulated the inflammatory response in microglia via exosomal transfer.

[Pollution Characteristics and Source of HULIS in the Fine Particle During the Beijing APEC].

In order to investigate the influence of the emission reduction measure during the Beijing APEC on the concentrations and pollution characteristics of humic-like substances (HULIS) in atmospheric fine particles, PM2.5 samples were collected and analyzed for OCEC, WSOC, HULIS and water-soluble ions. The concentration of HULIS in PM2.5 ranged 1 µg · m⁻³-15 µg · m⁻³. HULIS concentrations were 7.99 µg · m⁻³, 5.83 µg · m⁻³ and 7.06 µg · m⁻³ before, during and after APEC, which indicated emission reduction measure had important effect on the reduction of HULlS. The decrease of HULIS during the APEC was significantly faster than those of EC and WSOC, while the increase of HULIS turned out to be much slower than OC, EC, WSOC and PM2.5 after the meeting. The proportions of HULIS to PM2.5 were 13.60%, 13.59%, 14.02% and 12.22% at four different stages, i. e., whole sampling period, before, during and after the APEC, while HULIS-C/OC and HULIS-C/WSOC were 28.95%, 35.51%, 28.37%, 19.93%; and 52.75%, 59.58%, 51.54%, 45.39%, respectively. HULlS was significantly positively correlated with humidity, while significantly negatively correlated with wind speed. Biomass burning and secondary transformation of VOCs might be two important sources of HULlS in Beijing.