scholarly journals Small-molecule inhibitor of OGG1 suppresses proinflammatory gene expression and inflammation

Science ◽  
2018 ◽  
Vol 362 (6416) ◽  
pp. 834-839 ◽  
Author(s):  
Torkild Visnes ◽  
Armando Cázares-Körner ◽  
Wenjing Hao ◽  
Olov Wallner ◽  
Geoffrey Masuyer ◽  
...  

The onset of inflammation is associated with reactive oxygen species and oxidative damage to macromolecules like 7,8-dihydro-8-oxoguanine (8-oxoG) in DNA. Because 8-oxoguanine DNA glycosylase 1 (OGG1) binds 8-oxoG and because Ogg1-deficient mice are resistant to acute and systemic inflammation, we hypothesized that OGG1 inhibition may represent a strategy for the prevention and treatment of inflammation. We developed TH5487, a selective active-site inhibitor of OGG1, which hampers OGG1 binding to and repair of 8-oxoG and which is well tolerated by mice. TH5487 prevents tumor necrosis factor–α–induced OGG1-DNA interactions at guanine-rich promoters of proinflammatory genes. This, in turn, decreases DNA occupancy of nuclear factor κB and proinflammatory gene expression, resulting in decreased immune cell recruitment to mouse lungs. Thus, we present a proof of concept that targeting oxidative DNA repair can alleviate inflammatory conditions in vivo.

2018 ◽  
Vol 315 (5) ◽  
pp. E745-E757 ◽  
Author(s):  
Yanchun Li ◽  
Zhongyang Lu ◽  
Ji Hyun Ru ◽  
Maria F. Lopes-Virella ◽  
Timothy J. Lyons ◽  
...  

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease and consumption of high-fat diet (HFD) is a risk factor for NAFLD. The HFD not only increases intake of saturated fatty acid (SFA) but also induces metabolic endotoxemia, an HFD-associated increase in circulating lipopolysaccharide (LPS). Although it is known that SFA or LPS promote hepatic inflammation, a hallmark of NAFLD, it remains unclear how SFA in combination with LPS stimulates host inflammatory response in hepatocytes. In this study, we performed both in vivo and in vitro experiments to investigate the effect of SFA in combination with LPS on proinflammatory gene expression in hepatocytes. Our animal study showed that feeding low-density lipoprotein-deficient mice HFD enriched with SFA and injection of low-dose LPS cooperatively stimulated IL-6 expression in livers. To understand how SFA and LPS interact to promote IL-6 expression, our in vitro studies showed that palmitic acid (PA), a major SFA, and LPS exerted synergistic effect on the expression of IL-6 in hepatocytes. Furthermore, coculture of hepatocytes with macrophages resulted in a greater IL-6 expression than culture of hepatocytes without macrophages in response to the combination of PA and LPS. Finally, we observed that LPS and PA increased ceramide production by cooperatively stimulating ceramide de novo synthesis, which played an essential role in the synergistic stimulation of proinflammatory gene expression by LPS and PA. Taken together, this study showed that SFA in combination with LPS stimulated a strong inflammatory response in hepatocytes in vivo and in vitro.


2018 ◽  
Vol 96 ◽  
pp. 179-187 ◽  
Author(s):  
Jue Lin ◽  
Jie Sun ◽  
Stephanie Wang ◽  
Jeffrey M. Milush ◽  
Chris A.R. Baker ◽  
...  

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