Does prolonged biliary obstructive jaundice sensitize the liver to endotoxemia?

Area of Science:

• Hepatology
• Immunology
• Cellular Biology

Background:

• Obstructive jaundice (OJ) poses a high risk for bacteremia and cholestatic liver injury.
• Hepatocyte apoptosis is a key mechanism contributing to liver damage during cholestasis.

Purpose of the Study:

• To investigate the precise pathway and temporal course of hepatocyte apoptosis during obstructive jaundice.
• To determine if obstructive jaundice sensitizes the liver to lipopolysaccharide (LPS)-induced endotoxemia.

Main Methods:

• Male C57BL/6 mice underwent bile duct ligation, followed by LPS administration at 3 or 14 days post-surgery.
• Assessed Fas ligand expression, cleaved caspases 3/8/9, PARP cleavage, ALT levels, and hepatic ATP content.
• Evaluated survival rates in LPS-challenged mice, including Fas ligand-deficient (gld/gld) mice.

Main Results:

• Fas ligand expression increased during OJ. LPS administration elevated cleaved caspases 3 and 8, particularly in prolonged OJ (OJ14).
• Significant hepatocyte apoptosis and liver injury (increased ALT, decreased ATP) occurred in OJ14 mice post-LPS.
• Hepatocyte apoptosis and mortality were reduced in gld/gld mice compared to C57BL/6 mice during OJ with LPS.

Conclusions:

• Prolonged obstructive jaundice enhances hepatocyte apoptosis via the Fas ligand pathway, sensitizing the liver to endotoxemia.
• This Fas ligand-dependent apoptosis, coupled with decreased ATP, results in liver necrapoptosis and mortality during OJ with LPS exposure.