[P3-24] Effect of HMGB1 on crytococcus neoformans-induced permeability changes of the blood-brain barrier
[Introduction]
Cryptococcus in blood circulation is reported to penetrate through the blood-brain barrier (BBB) to cause meningoencephalitis. HMGB1 usually becomes active during infection and inflammation, and participate in brain injury. Here we foucused on the effects and mechanisms of HMGB1 on the changes of BBB permeability after infection with cryptococcus neoformans in human brain microvasclar endothelial cells (HBMEC).
[Methodology]
BBB model was established in vitro by HBMECs, then intervened with cryptococcus neoformans. Western blot and immuno-fluorescence method were used to detect the expressions of HMGB1 and RAGE in HBMECs at 8h, 16h, 24h, 32h, 48h after incubation. Additionally, HBMECs was pre-intervened with rHMGB1, anti-HMGB1 neutralizing antibody one hour before infection. The expressions of HMGB1 and RAGE at 24h were observed, and HBMEC monolayer’s permeability of all groups was examined through ELISA.
[Results]
The cytoplasmic HMGB1 level increased at 16h and peaked at 24h, then gradually decreased at 32h and 48h after incubation. However, the expressions of HMGB1 protein in the nucleus showed the opposite trend. The RAGE and cytoplasmic HMGB1 proteins showed the consistent trend and had a significant positive correlation. Additionlly, rHMGB1 improved the expressions of cytoplasmic HMGB1 and RAHE and accelerate the translocation of HMGB1, while anti-HMGB1 neutralizing antibody blocked this process. ELISA showed the optical density (OD) values of HRP significantly increased at 16 h, and had a steadily higher level at 24h, 32h and 48h. Also the OD value of HRP were positively associated with the HMGB1/RAGE protein separately. Moreover, rHMGB1 obviously increased the OD values of HRP after infection while anti-HMGB1 decreased it.
[Conclusions]
In current study, we demonstrated that the BBB permeability increased significantly after cryptococcus neoformans infection through the HMGB1/RAGE pathway.
Cryptococcus in blood circulation is reported to penetrate through the blood-brain barrier (BBB) to cause meningoencephalitis. HMGB1 usually becomes active during infection and inflammation, and participate in brain injury. Here we foucused on the effects and mechanisms of HMGB1 on the changes of BBB permeability after infection with cryptococcus neoformans in human brain microvasclar endothelial cells (HBMEC).
[Methodology]
BBB model was established in vitro by HBMECs, then intervened with cryptococcus neoformans. Western blot and immuno-fluorescence method were used to detect the expressions of HMGB1 and RAGE in HBMECs at 8h, 16h, 24h, 32h, 48h after incubation. Additionally, HBMECs was pre-intervened with rHMGB1, anti-HMGB1 neutralizing antibody one hour before infection. The expressions of HMGB1 and RAGE at 24h were observed, and HBMEC monolayer’s permeability of all groups was examined through ELISA.
[Results]
The cytoplasmic HMGB1 level increased at 16h and peaked at 24h, then gradually decreased at 32h and 48h after incubation. However, the expressions of HMGB1 protein in the nucleus showed the opposite trend. The RAGE and cytoplasmic HMGB1 proteins showed the consistent trend and had a significant positive correlation. Additionlly, rHMGB1 improved the expressions of cytoplasmic HMGB1 and RAHE and accelerate the translocation of HMGB1, while anti-HMGB1 neutralizing antibody blocked this process. ELISA showed the optical density (OD) values of HRP significantly increased at 16 h, and had a steadily higher level at 24h, 32h and 48h. Also the OD value of HRP were positively associated with the HMGB1/RAGE protein separately. Moreover, rHMGB1 obviously increased the OD values of HRP after infection while anti-HMGB1 decreased it.
[Conclusions]
In current study, we demonstrated that the BBB permeability increased significantly after cryptococcus neoformans infection through the HMGB1/RAGE pathway.