Korean J Transplant.  2023 Nov;37(Suppl 1):S92. 10.4285/ATW2023.F-6754.

Role of protease-activated receptor-1 in the inflammatory response in a coculture model of pig endothelial cells and human monocytes

• Hoang TX
• Bang JY
• Lee MG
• Tran TM
• Jung J
• Lee HH
• Kang HJ
• Yun IJ
• Kim JY

• KMID: 2551679
• DOI: http://doi.org/10.4285/ATW2023.F-6754

Abstract

Coagulation dysregulation and persistent systemic inflammation are critical huddles for successful pig-to-primate solid organ xenotransplantation. Protease-activated receptors (PARs) are a family of G protein-coupled receptors that play a role in inflammation and coagulation through their interaction with the ligand thrombin. In this study, we investigated the role of PAR-1 in the expression of inflammatory mediators and intracellular calcium ion levels in a coculture model of pig endothelial cells (pECs) and human monocytes (hMOs), using a PAR-1 inhibitor and human thrombin. PAR-1 inhibition reversed the increased expres-sion of inflammatory mediators and tissue factors in pEC-hMO cocultures. Human thrombin increased intracellular Ca ²⁺ levels in hECs but not pECs. PAR-1 inhibition reversed the enhanced Ca ²⁺ levels in hECs. Human thrombin enhanced the expression of inflammatory mediators and endothelial permeability in hECs but not pECs. PAR-1 inhibition reversed the enhanced expression of inflammatory mediators and endothelial permeability in hECs. Human thrombin enhanced PAR-1 phosphorylation, which was suppressed by the PAR-1 inhibitor. The unresponsiveness of pECs to human thrombin was found to be due to the difference in the amino acid sequence of PAR-1 between humans and pigs. This study has demonstrated, for the first time, the molecular incompatibility of PAR-1 between humans and pigs. This work was supported by the Cooperative Research Program for Agriculture Science and Technology Development (Project No. PJ015607).