J. Xu1, J. Hu1, C. Zgheib1, M. M. Hodges1, K. W. Liechty1 1University Of Colorado-Anschutz Medical Campus,Department Of Surgery, Laboratory For Fetal And Regenerative Biology,Aurora, CO, USA
Introduction: Recent studies reveal that long non-coding RNAs (lncRNAs) play important regulatory roles in many biological processes. We have previously shown that the lncRNA Lethe is down-regulated in diabetic wounds and that Lethe is involved in the regulation of Reactive oxygen species (ROS) production in macrophages, indicating a potential role for Lethe in the pathogenesis of diabetic wounds. RNA binding protein HuR stabilizes mRNA by binding to 3’UTR of mRNA and inhibiting microRNA binding. We hypothesize that hyperglycemia reduces Lethe expression by alteration of HuR binding.
Methods: To test our hypothesis, we incubated the murine macrophage cell line RAW264.7 with media containing 5 mM glucose (low glucose), or 25 mM glucose (high glucose) for 24 hours. RNA immunoprecipitation (RIP) was used to analyze HuR binding and Real-time PCR used to quantify relative gene expression.
Results: Lethe was significantly down-regulated in high glucose conditions. Under low glucose conditions, the level of lethe in the anti-HuR immunoprecipitated lysate was significantly higher than in the IgG control group. Under high glucose conditions, the level of lethe was not significantly different between the anti-HuR group and IgG control group, and was significantly lower compared to anti-HuR group under low glucose conditions.
Conclusion: These findings demonstrate a novel mechanism in the regulation of the effects of lncRNA Lethe expression, with HuR binding to lncRNA Lethe and hyperglycemia reduces HuR binding to Lethe to de-stabilize Lethe. Furthermore, these results may represent a potential novel therapeutic target to correct the impaired diabetic wound healing response.