2-Chloro- and 2-Bromopalmitic acids inhibit mitochondrial function in airway epithelial cells

Area of Science:

• Biochemistry
• Cell Biology
• Pulmonary Medicine

Background:

• 2-Chloropalmitic acid (2-ClPA) and 2-bromopalmitic acid (2-BrPa) are implicated in inflammatory lung diseases.
• The precise mechanisms by which these lipids cause lung injury remain unclear.
• Mitochondrial dysfunction is a potential contributor to cellular damage in lung disease.

Purpose of the Study:

• To investigate if 2-ClPA and 2-BrPA induce metabolic defects in airway epithelial cells.
• To determine if mitochondria are the primary targets of 2-halofatty acids.
• To elucidate the impact of these lipids on cellular bioenergetics.

Main Methods:

• H441 and primary human airway epithelial cells were treated with 2-ClPA or 2-BrPA.
• Cellular bioenergetics were assessed using oxygen consumption rates (OCR) and extracellular acidification rates (ECAR).
• Mitochondrial respiratory complex activities were measured.

Main Results:

• Both 2-ClPA and 2-BrPA inhibited ATP-linked oxygen consumption and reserve capacity.
• Mitochondrial membrane potential remained unchanged, indicating proton leak does not explain the observed effects.
• Complex II activity was significantly inhibited, while complexes I, III, and IV were unaffected.

Conclusions:

• 2-halofatty acids disrupt cellular bioenergetics in airway epithelial cells.
• Inhibition of mitochondrial complex II is a key mechanism underlying the observed metabolic defects.
• These findings highlight the potential of 2-halofatty acids to cause cellular dysfunction and contribute to lung injury.