High glucose potentiates Zika virus induced-astroglial dysfunctions

Zika virus (ZIKV) is a neurotropic flavivirus that induces congenital Zika syndrome and neurodevelopmental disorders. Given that ZIKV can infect and replicate in neural cells, neurological complications in adult brain are also observed. Glial cells may emerge to delay and/or prevent the development of ZIKV-induced neurodegeneration. These cells actively participate in metabolic, inflammatory and redox processes, and consequently, in the pathophysiology of neurodegenerative diseases, including diabetic encephalopathy. In this sense, changes in glucose metabolism can support the inflammatory activity of astroglial cells; however, the effects of increased glucose concentration during ZIKV infection have not yet been explored in astroglial cells. Here, we evaluated functional parameters of astroglial cells exposed to ZIKV upon normal and high glucose concentrations, focusing on inflammatory profile, oxidative stress, and expression of critical genes for astroglial functions. High glucose potentiated the pro-inflammatory and oxidative effects of ZIKV, as well as potentiated the downregulation of signaling pathways, such as Nrf-2 (nuclear factor erythroid derived 2 like 2), sirtuin 1 (SIRT1), peroxisome proliferator activated receptor gamma coactivator 1-alpha (PGC-1α), and poly (ADP-ribose) polymerase (PARP). In summary, our results suggest that high glucose can favor the activation of inflammatory signaling while impairing cytoprotective pathways in astroglial cells exposed to ZIKV and reinforce the hypothesis that this virus is highly neurotrophic, with significant impact in glial cells.