ABSTRACT
Objective:To investigate the effects and mechanism of cannabinoid (CBD) on the anxiety- and depression-like behaviors induced by lipopolysaccharide (LPS) in mice.Methods:C57BL/6J mice were intraperitoneally injected with LPS to establish the model of neuroinflammation. CBD was injected intraperitoneally 24 h after modeling. Behavioral tests were performed to evaluate the anxiety- and depression-like behaviors in mice. CBD-pretreated BV-2 microglia cells were stimulated with LPS in vitro. The levels of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β) and CD86 in mouse cerebral cortex, hippocampus, prefrontal cortex and BV-2 cells were measured by qRT-PCR. The protein level of nuclear factor (NF-κB) in mouse brain and BV-2 cells was determined by Western blot. Results:CBD significantly increased the residence time and movement distance of LPS-treated mice in the central area in the open filed test (OFT), and reduced the immobility time in tail suspension test (TST) and force swimming test (FST). In addition, CBD alleviated the neuroinflammation and inhibited the activation of microglia in mouse brain. In vitro, CBD significantly inhibited the activation of BV-2 microglia cells. Both in vivo and in vitro experiments confirmed that CBD could inhibit NF-κB expression. Conclusions:LPS could induce the activation of BV-2 microglia cells and the expression of inflammatory factors in mouse brain accompanied with abnormal behaviors. CBD could inhibit the activation of microglia, alleviate the neuroinflammation in different regions of mouse brain and improve behavioral performance.
ABSTRACT
Objective To study the pathway of miR-221/222 in enhancing radiation resistance of glioblastoma.Methods After 2 Gy of X-ray irradiation,the expressions of miR-221/222 in U251,U87 and LN229 glioblastma cells were detected with real-time PCR.Clonogenic assay was used to measure the radiosensitivity of glioblastoma after knocking down miR-221/222.ChIP assay was used to identify the combination situation of c-jun and miR-221/222.Luciferase assay was applied to check whether PTEN was a target of miR-221/222.Western blot was used to detect the expression of relevant proteins in the glioblastoma cells after knocking down miR-221/222.The effect of miR-221/222 and irradiation on growth of glioblastoma in nude mice was also observed.Results The expression of miR-221/222 was increased by irradiation(t =5.48 ～29.21,P ＜ 0.05) and the radiosensitivity of anti-miR-221/222-transfected cells was alsoincreased(F=1 202.22,1 789.12,1 012.32,P＜0.05).MiR-221/ 222 was transcriptionally regulated by c-jun with a target of PTEN (t =13.16,P ＜ 0.05).When miR-221/222 was knocked-down,the expression of pAkt and DNA-PKcs were down-regulated while PTEN and GSK-3β were up-regulated,and the expression of Akt were not changed.Moreover,the growth of xenograft tumor was significantly inhibited by the combination treatment of anti-miR-221/222 and irradiation(F =56.36,P ＜ 0.05).Conclusions The expression of miR-221/222 in glioblastoma cells can be increased by irradiation,and the activation of Akt pathway downstream miR-221/222 could enhance the radiation resistance of glioblastoma.