Long chain fatty acids can form aggregates and affect the membrane integrity

Area of Science:

• Biochemistry
• Cell Biology
• Membrane Biophysics

Background:

• Fatty acids (FAs), including stearic acid (SA) and oleic acid (OA), are endogenous compounds affecting cell membranes.
• Existing research presents conflicting views on whether FA effects are beneficial or detrimental.
• Clarifying FA roles in disease etiology and treatment is essential.

Purpose of the Study:

• Investigate the aggregation behavior of long-chain FAs (SA and OA).
• Determine the impact of FA aggregation on membrane integrity.
• Assess the effects of FA aggregates on cell viability across different cell lines.

Main Methods:

• Determined the critical aggregation concentration (CAC) for SA (1110 μM) and OA (300 μM).
• Utilized Transmission Electron Microscopy (TEM) to visualize FA aggregate structures.
• Assessed membrane integrity using lipid junction disruption assays.
• Evaluated cell viability in various cell lines exposed to FA aggregates.

Main Results:

• TEM revealed distinct aggregation patterns: hexagonal for SA and spherical for OA.
• Both SA and OA disrupted membrane integrity below and above their respective CACs.
• SA exhibited greater cytotoxicity than OA across all tested cell lines.
• SA's effect on PC3 cell viability was concentration-dependent and amplified above CAC.
• OA demonstrated a proliferative effect on PC3 cells.

Conclusions:

• The aggregation behavior of FAs significantly influences their impact on cell membranes and viability.
• SA and OA exhibit differential effects on membrane integrity and cell death.
• Consideration of FA aggregation is vital for understanding physiological functions and developing therapeutic strategies.