Figure 17.

Proof‐of‐principle of the proinflammatory activity of cardiac sPLA₂. A, Strategy for preparative isolation of cardiac sPLA₂ from Mmp2^−/− mice (donor). Hearts were excised and homogenized, cardiac proteins (from 500 mg tissue) were resolved by nonreducing SDS‐PAGE. After reverse staining, protein eluted from the gel was assessed for sPLA₂ activity, and the active fraction was filter‐sterilized and injected into WT mice (recipient). An aliquot was used for enzyme kinetic analysis to confirm its identity (ie, same K_M^app) as the sPLA₂ found in cardiac homogenates and plasma. B, sPLA₂ activity in the plasma and hearts of WT mice injected with cardiac sPLA₂ isolated from Mmp2^−/− mice. n=3 WT mice. *P≤0.05 vs vehicle, t test. C, qRT‐PCR of inflammatory marker genes in WT mice injected with cardiac sPLA₂ isolated from Mmp2^−/− mice. n=3 WT mice. *P≤0.05 vs vehicle, t test. MMP indicates matrix metalloproteinase; qRT‐PCR, quantitative real‐time polymerase chain reaction; SDS‐PAGE, sodium‐dodecylsulfate polyacrylamide gel electrophoresis; sPLA₂, secreted phospholipase A₂; WT, wild‐type.