Immuno-pathophysiological role of miR-23b and ROS in sepsis in newborns

Abstract

bstract Background: Neonatal sepsis represent a major challenge in public health, where is the third most common cause of death of newborns. Neonatal sepsis characterized by misunderstood either at the molecular or at the cellular level. Here, in our study, we investigated the role of miRNA-23b in neonatal sepsis, and we studied the effect of reactive oxygen species in the activity of endothelial cells in sepsis. Methods: Our study has two main parts. A prospective study based on Fifty-four newborns suspected sepsis. By RT-qPCR, we quantified the level of miRNA-23b in hemoculture. Via an ex-vivo model, we used the umbilical cord, which's divided into four groups. Where the exposure to oxidative stress caused by CuSO4 and sepsis by Staphylococcus aureus. After 1 hour of incubation, we isolated endothelial cells and studied them. Results: our study showing the relationship between sepsis and miRNA-23b, where We have shown that miRNA-23b levels increased in premature and full-term newborns in the case of EOS (p < 0.001 and p < 0.005 respectively), but decreased in LOS (p < 0.005). And proved the negative correlation between newborns who died from sepsis and miRNA-23b level. In the ex-vivo model, we have shown endothelial cells behaved differently against bacteria in the four conditions With betamethasone and without CuSO4, we noted the translocation of bacteria to the blood with a decrease in the level of miR-23b. Injection of CuSO4 into the blood induces a change in the activity of ECs and neutralizes the level of miR-23b, contribute to the defense against the translocation of bacteria in the blood. Conclusions: The decrease in miRNA-23b levels would undoubtedly be an important factor favoring the development of neonatal sepsis. In addition to the protective role of copper-induced oxidative stress, activated endothelial cells promoting the pro-inflammatory response in the blood may help prevent the translocation of S. aureus to the blood. Key words: Neonatal Sepsis, Endothelial Cells, Reactive Oxygen Species (ROS), miRNA- 23b.