Purpose
The purpose of this study was to characterize and quantitatively analyze human cardiac extracellular matrix (ECM) isolated from six different cadaveric donor hearts. Experimental design: ECM was isolated by decellularization of six human cadaveric donor hearts and characterized by quantifying sulfated glycosaminoglycan content (sGAG) and via PAGE. The protein content was then quantified using ECM-targeted Quantitative conCATamers (QconCAT) by LC-SRM analysis using 83 stable isotope labeled (SIL) peptides representing 48 different proteins. Nontargeted global analysis was also implemented using LC-MS/MS.
Results
The sGAG content, PAGE, and QconCAT proteomics analysis showed significant variation between each of the six patient samples. The quantitative proteomics indicated that the majority of the protein content was composed of various fibrillar collagen components. Also, quantification of difficult to remove cellular proteins represented less than 1% of total protein content, which is very low for a decellularized biomaterial. Global proteomics identified over 200 distinct proteins present in the human cardiac ECM.