The decrease of PKCalpha is associated with hepatic apoptosis at early and late phases of polymicrobial sepsis.

Area of Science:

• Hepatology
• Molecular Biology
• Immunology

Background:

• Sepsis is a life-threatening condition characterized by a dysregulated host response to infection.
• Hepatic apoptosis is a significant contributor to organ dysfunction during sepsis.
• The role of Protein Kinase C-alpha (PKC-alpha) in sepsis-induced liver injury remains unclear.

Purpose of the Study:

• To investigate the relationship between PKC-alpha and hepatic apoptosis in a sepsis model.
• To elucidate the molecular mechanisms underlying sepsis-induced liver cell death.

Main Methods:

• A cecal ligation and puncture (CLP) model of polymicrobial sepsis in animals.
• Quantification of PKC-alpha, Bcl-2 family proteins (Bcl-2, Bcl-xL, Bax), and PARP cleavage.
• Assessment of hepatocyte apoptosis using gel electrophoresis, flow cytometry (Annexin-V-Fluos, propidium iodide), and DNA fragmentation assays.
• In vitro study using PKC-alpha antisense treatment in hepatocytes.

Main Results:

• Membrane-associated PKC-alpha expression decreased during early and late sepsis.
• Bcl-2 and Bcl-xL levels decreased, while Bax expression increased in late sepsis.
• Poly(ADP-ribose) polymerase (PARP) cleavage and hepatocyte apoptosis were significantly elevated in both early and late sepsis.
• PKC-alpha antisense treatment exacerbated apoptosis in hepatocytes.
• Severe DNA fragmentation was observed in late sepsis.

Conclusions:

• PKC-alpha inactivation plays a crucial role in modulating hepatic apoptosis during sepsis.
• Sepsis-induced liver apoptosis is closely associated with alterations in Bcl-2 family protein expression.
• Targeting PKC-alpha may offer a therapeutic strategy for sepsis-induced liver injury.