Direct Effect of Septic Plasma in Human Cell Lines Viability

Area of Science:

• Cellular Biology
• Immunology
• Pathophysiology

Background:

• Sepsis is a life-threatening condition causing multiple organ injuries.
• The immune response and inflammatory mediators are implicated in organ damage.
• The direct cellular mechanisms of sepsis-induced organ injury remain unclear.

Purpose of the Study:

• To investigate the in vitro cellular response of renal tubular cells (RTCs), monocytes (U937), and hepatocytes (HepG2) to septic patients' plasma.
• To elucidate the direct cellular mechanisms of sepsis-induced organ injury.

Main Methods:

• Incubation of RTCs, U937, and HepG2 cells with plasma from 26 septic patients.
• Assessment of cell viability, apoptosis, and necrosis using flow cytometry.
• Quantification of Caspase-3, -8, -9, and cytochrome-c levels via ELISA.

Main Results:

• Septic plasma decreased cell viability in all tested cell lines.
• Increased apoptosis was observed in RTCs and U937 cells (p < 0.0001).
• Increased necrosis was observed in HepG2 cells (p < 0.5).
• Apoptosis in RTCs and U937 cells was mediated by the intrinsic pathway, evidenced by increased Caspase-9 and cytochrome-c levels (p < 0.0001).

Conclusions:

• Humoral mediators in septic plasma directly induce apoptosis in renal tubular cells and monocytes.
• These findings suggest that apoptosis inhibitors could be a therapeutic strategy for sepsis-induced organ damage.