Chronic
inflammation and concomitant oxidative stress can induce
mitochondrial dysfunction due to
cardiolipin (CL) abnormalities in the mitochondrial inner membrane. To examine the responses of mitochondria to
inflammation, macrophage-like RAW264.7 cells were activated by
Kdo2-Lipid A (KLA) in our
inflammation model, and then the mitochondrial CL profile, mitochondrial activity, and the
mRNA expression of CL metabolism-related genes were examined. The results demonstrated that KLA activation caused CL desaturation and the partial loss of mitochondrial activity. KLA activation also induced the gene upregulation of
cyclooxygenase (COX)-2 and
phospholipid scramblase 3, and the gene downregulation of COX-1,
lipoxygenase 5, and Δ-6 desaturase. We further examined the phophatidylglycerol (PG) inhibition effects on
inflammation. PG supplementation resulted in a 358-fold inhibition of COX-2
mRNA expression. PG(18:1)2 and PG(18:2)2 were incorporated into CLs to considerably alter the CL profile. The decreased CL and increased
monolysocardiolipin (MLCL) quantity resulted in a reduced CL/MLCL ratio. KLA-activated macrophages responded differentially to PG(18:1)2 and PG(18:2)2 supplementation. Specifically, PG(18:1)2 induced less changes in the CL/MLCL ratio than did PG(18:2)2, which resulted in a 50% reduction in the CL/MLCL ratio. However, both PG types rescued 20-30% of the mitochondrial activity that had been affected by KLA activation.