Proteomic Analysis of the Extracellular Matrix in the Porcine Adrenal Cortex

The extracellular matrix (ECM) is a complex network of proteins that provides structural support and influences tissue boundaries, biomechanical properties, and cell polarity. This study analyzed the ECM profile of the porcine adrenal cortex's outer (OF = capsule + subcapsular + zona glomerulosa cells) and inner fractions (IF = zona fasciculata cells). Proteomic analysis of decellularized OF and IF samples identified 940 proteins, 27 collagens, 44 ECM glycoproteins, 9 proteoglycans, 20 ECM regulators, 5 ECM-associated proteins, 6 secreted factors, and 39 ECM candidates to compose the specific porcine adrenal matrisome. Among the ECM proteins identified, 113 are common to the OF and IF, while 16 were identified only in the OF and 21 in the IF. The analysis of protein abundance differences showed three proteins (Lamc1, Perlecan, and Tgm2) significantly abundant in OF compared to IF. In IF, 11 proteins (Col1α1, Col1α2, Col6α1, Col6α2, Col6α3, Col6α6, Col14α1, Ecm1, Fga, Fgb, and Fgg) were more abundant than OF. The comparative analysis of the quantification ECM proteins from the decellularized adrenal cortex of rats, humans, and pigs showed that in porcine samples, the ECM-quantified proteins are more abundant in the IF, while in rats and human samples, the more abundant ECM-quantified proteins are in the OF. These findings provide valuable insights into the potential of using pigs as a biomedical model and an essential tool for translational medical research.