Released Mitochondrial DNA Following Intestinal Ischemia Reperfusion Induces the Inflammatory Response and Gut...

Area of Science:

• Gastroenterology
• Immunology
• Cell Biology

Background:

• Ischemia-reperfusion (I/R) injury poses significant clinical challenges, particularly in the gastrointestinal tract.
• Mitochondrial DNA (mtDNA) release during cell death and stress can initiate inflammatory responses.

Purpose of the Study:

• To investigate the specific role of mitochondrial DNA (mtDNA) in the pathogenesis of intestinal I/R injury.
• To explore the potential of mtDNA as a biomarker for intestinal I/R.

Main Methods:

• Established an in vivo intestinal I/R mouse model and an in vitro hypoxia/reoxygenation (H/R) model using IEC-6 cells.
• Assessed oxidative stress, mitochondrial function, apoptosis, and mtDNA release.
• Co-cultured mtDNA with human primary dendritic cells to evaluate inflammatory responses via TLR9-MyD88 signaling.

Main Results:

• Hypoxia/reoxygenation (H/R) increased oxidative stress, impaired mitochondrial activity and membrane potential, induced apoptosis, and elevated mtDNA levels in intestinal epithelial cells.
• Co-culture with mtDNA significantly upregulated TLR9-MyD88 expression and enhanced inflammatory cytokine/chemokine production.
• Intestinal I/R in mice led to mtDNA release, increased inflammatory cytokine secretion, and exacerbated gut barrier injury compared to sham controls.

Conclusions:

• Mitochondrial DNA (mtDNA) actively contributes to the pathogenesis of intestinal I/R injury.
• Released and potentially oxidized mtDNA exacerbates inflammation by stimulating cytokine and chemokine production.
• mtDNA shows promise as a diagnostic biomarker for intestinal I/R injury.