Organotypic hippocampal culture model reveals differential responses to highly similar Zika virus isolates

Ruxolitinib attenuates microglial inflammatory response by inhibiting NF-κB/MAPK signaling pathway

Neuroinflammation is involved in the physiological and pathological processes of numerous neurological diseases, and its inhibition seems to be a promising therapeutic direction for these diseases. Ruxolitinib is a classical Janus kinase (JAK) inhibitor that is oral, highly potent and bioavailable, which has recently gained approval from the US Food and Drug Administration (FDA) for the treatment of inflammatory disorders. The potential inhibitory effect of ruxolitinib on neuroinflammation has not been fully studied. In the lipopolysaccharide (LPS) induced neuroinflammatory cell model, we observed that ruxolitinib reduced the levels of IL-1β, IL-6 and tumor necrosis factor-α (TNF-α) expression, and neuroinflammation by inhibiting the Mitogen-Activated Protein Kinase/Nuclear factor-κ B (MAPK/NF-κB) signaling pathway. Similarly, mice injected intracerebroventricular with ruxolitinib exhibited significantly reduced LPS-stimulated activation of microglia and astrocytes, and expression of proinflammatory cytokine IL-1β, TNF-α and IL-6. These results demonstrate that ruxolitinib attenuates the neuroinflammatory responses both in vivo and in vitro, at least in part by inhibiting MAPK/NF-κB signaling pathway. Our findings suggest that ruxolitinib may serve as a potential drug for the treatment of microglia-mediated neuroinflammation.

Influence of Zika virus on the cytotoxicity, cell adhesion, apoptosis and inflammatory markers of glioblastoma cells

Glioblastoma (GBM) is one of the most common types of brain tumor in adults. Despite the availability of treatments for this disease, GBM remains one of the most lethal and difficult types of tumors to treat, and thus, a majority of patients die within 2 years of diagnosis. Infection with Zika virus (ZIKV) inhibits cell proliferation and induces apoptosis, particularly in developing neuronal cells, and thus could potentially be considered an alternative for GBM treatment. In the present study, two GBM cell lines (U-138 and U-251) were infected with ZIKV at different multiplicities of infection (0.1, 0.01 and 0.001), and cell viability, migration, adhesion, induction of apoptosis, interleukin levels and CD14/CD73 cell surface marker expression were analyzed. The present study demonstrated that ZIKV infection promoted loss of cell viability and increased apoptosis in U-138 cells, as measured by MTT and triplex assay, respectively. Changes in cell migration, as determined by wound healing assay, were not observed; however, the GBM cell lines exhibited an increase in cell adhesion when compared with non-tumoral cells (Vero). The Luminex immunoassay showed a significant increase in the expression levels of IL-4 specifically in U-251 cells (MOI 0.001) following exposure to ZIKV. There was no significant change in the expression levels of IFN-γ upon ZIKV infection in the cell lines tested. Furthermore, a marked increase in the percentage of cells expressing the CD14 surface marker was observed in both GBM cell lines compared with in Vero cells; and significantly increased CD73 expression was observed particularly in U-251 cells, when compared with uninfected cells. These findings indicate that ZIKV infection could lead to reduced cell viability, elevated CD73 expression, improved cellular adherence, and higher rates of apoptosis in glioblastoma cells. Further studies are required to explore the potential use of ZIKV in the treatment of GBM.