Significance of mitochondrial DNA in neonates with acute respiratory distress syndrome

Abstract

Abstract Background To analyze peripheral blood mitochondrial DNA levels in neonates with neonatal acute respiratory distress syndrome(ARDS) and to assess their correlation with the severity of ARDS. Method Neonates diagnosed with ARDS from January 2021 to January 2023 were included as a study group prospectively. According to the Oxygen index (OI), they were divided into mild ARDS group (4 ≤ OI < 8), moderate ARDS group (8 ≤ OI < 16), and severe ARDS group (OI ≥ 16). The control group was selected from jaundiced neonates who were observed in the neonatal unit of the hospital during the same period. Peripheral blood samples were collected on days 1, 3, and 7 after admission in the ARDS group, and on admission in the control group. Real-time quantitative PCR was used to detect the expression levels of mtDNA and cGAS -STING mRNA, and ELISA was used to detect the levels of serum IL-6, IL-23, and IFN-γ. Pearson correlation analysis was used to assess the correlation between serum mtDNA and serum IL-6, IL-23, and IFN-γ levels. Results 50 newborns were enrolled in the ARDS group, including 25 with mild ARDS, 15 with moderate ARDS, and 10 with severe ARDS, control group included 25 neonates. Compared with the control group, serum levels of mtDNA, cGAS -STING mRNA, IL-6, IL-23, and IFN-γ were significantly increased in the ARDS groups (P < 0.05). Compared with the mild ARDS group, serum mtDNA, cGAS -STING mRNA, IL-6, IL-23, and IFN-γ levels were significantly increased in the moderate and severe ARDS groups (P < 0.05). Compared with day 1, serum mtDNA, cGAS -STING mRNA, IL-6, IL-23, and IFN-γ levels significantly increased on day 3 and significantly decreased on day 7 in all ARDS groups (P < 0.05). Pearson correlation analysis showed that serum mtDNA levels were correlated with serum IL-6, IL-23, IFN-γ, and cGAS -STING mRNA levels (P < 0.05). Conclusion Elevated ARDS mtDNA levels may produce inflammatory mediators IL-6, IL-23, and IFN-γ by activating the cGAS -STING mRNA signaling pathway. MtDNA levels may have clinical value in assessing the severity of neonatal ARDS and in the earlier diagnosis of ARDS.