Abstract
Purpose :
Previously, we showed that bacterial (Staphylococcus aureus, SA) infection induced a glycolytic response in retinal microglia and the mouse retina (PMID: 27264993).The aim of this study is to investigate the physiological role of glycolysis in bacterial endophthalmitis using a glycolytic inhibitor, 2-deoxyglucose (2DG).
Methods :
In vitro studies were performed using mouse bone marrow derived macrophages (BMDM), and neutrophils; in vivo studies were performed utilizing a C57BL/6 mouse model of staphylococcal endophthalmitis. Glycolytic response was inhibited by pre-treatment of cultured innate immune cells with 2DG, followed by challenge with either live or heat-killed S. aureus (HKSA). Similarly, B6 mice were treated with 2DG to assess the effect in vivo. Infected cells/tissue were subjected to cytokine/chemokine ELISA, expression of inflammatory mediators by qPCR, and inflammatory signaling activation by immunoblotting.
Results :
Our data showed both live SA and HKSA induced inflammatory response in cultured macrophages and neutrophils, as evidenced by increased expression of pro-inflammatory mediators (Il-1β, Tnf-α, Il-6, Cxcl1) at mRNA and protein levels. This response was significantly attenuated in cells treated with 2DG. Western blot analysis revealed that, among the MAPK pathways, 2DG treatment affected ERK signaling with decreased phosphorylation of ERK. Moreover, mice treated with 2DG showed decreased inflammatory markers in infected tissue.
Conclusions :
Collectively, our data indicate that blocking the glycolytic pathway suppresses the inflammatory response in bacterial endophthalmitis and cultured macrophages and neutrophils. Further studies are warranted to elucidate the mechanisms underlying anti-inflammatory properties of 2DG in response to bacterial infection.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.