Plasma Fractionation Enriches Post-Myocardial Infarction Samples Prior to Proteomics Analysis

الملخص EN

Following myocardial infarction (MI), matrix metalloproteinase-9 (MMP-9) levels increase, and MMP-9 deletion improves post-MI remodeling of the left ventricle (LV).

We provide here a technical report on plasma-analysis from wild type (WT) and MMP-9 null mice using fractionation and mass-spectrometry-based proteomics.

MI was induced by coronary artery ligation in male WT and MMP-9 null mice (4–8 months old; n=3/genotype).

Plasma was collected on days 0 (pre-) and 1 post-MI.

Plasma proteins were fractionated and proteins in the lowest (fraction 1) and highest (fraction 12) molecular weight fractions were separated by 1-D SDS-PAGE, digested in-gel with trypsin and analyzed by HPLC-ESI-MS/MS on an Orbitrap Velos.

We tried five different fractionation protocols, before reaching an optimized protocol that allowed us to identify over 100 proteins.

Serum amyloid A substantially increased post-MI in both genotypes, while alpha-2 macroglobulin increased only in the null samples.

In fraction 12, extracellular matrix proteins were observed only post-MI.

Interestingly, fibronectin-1, a substrate of MMP-9, was identified at both day 0 and day 1 post-MI in the MMP-9 null mice but was only identified post-MI in the WT mice.

In conclusion, plasma fractionation offers an improved depletion-free method to evaluate plasma changes following MI.