Circular RNA circFADS2 is Overexpressed in Sepsis and Suppresses LPS-Induced Lung Cell Apoptosis by Inhibiting the Maturation of miR-15a-5p

Abstract Circular RNA circFADS2 plays protective roles in LPS-induced inflammation, which promotes sepsis, suggesting its involvement of circFADS2 in sepsis. We then analysis the involvement of circFADS2 in LOS Expression of circFADS2, mature miR-15a-5p and miR-15a-5p precursor in plasma samples (collected at two time points) from sepsis patients (n=60) and healthy controls (n=60) was determined by RT-qPCR. The expression vector of circFADS2 was transfected in lung cells, followed by the measurement of the expression levels of mature miR-15a-5p and miR-15a-5p precursor to study the role of circFADS2 in the maturation of miR-15a-5p. Cell apoptosis was analyzed by cell apoptosis assay.CircFADS2 was upregulated in sepsis and inversely correlated with mature miR-15a-5p, but not miR-15a-5p precursor. In lung cells, overexpression of circFADS2` decreased the levels of mature miR-15a-5p expression, but not miR-15a-5p precursor. LPS treatment decreased the expression levels of miR-15a-5p, and increased the expression levels of circFADS2. Cell apoptosis analysis showed that circFADS2 overexpression reduced the enhancing effects of miR-15a-5p overexpression on the apoptosis of lung cells induced by LPS.Therefore, circFADS2 is upregulated in sepsis and suppresses LPS-induced lung cell apoptosis by inhibiting the maturation of miR‑15a‑5p.