Unfractionated Heparin Attenuates Histone-Induced Pulmonary Endothelial Glycocalyx Injury: A Preliminary Study on the Roles of the ROCK Pathway and Heparanase‑1

Xinghua Li, Yawen Chi, Mengke Zhuo, Xin Li, Chengrui Zhu, Xu Li Department of Critical Care Medicine, The First Affiliated Hospital, China Medical University, Shenyang, Liaoning Province, People’s Republic of ChinaCorrespondence: Xu Li, Department of Critical Care Medicine, The First Affiliated Hospital, China Medical University, North Nanjing Street 155, Shenyang, Liaoning Province, 110001, People’s Republic of China, Tel +86 024 83282261, Fax +86 024 83282631, Email [email protected]: This study aims to investigate the role of the Rho-associated kinase (ROCK)-1 pathway, with the involvement of heparanase (HPA)-1, in histone-induced disruption of the endothelial glycocalyx and the protective effects of unfractionated heparin (UFH).Methods: Human pulmonary microvascular endothelial cells (HPMECs) were cultured in vitro and divided into 4 groups: control group, histone group, histone+UFH group, and histone+ROCK inhibitor (Y27632) group. The control group was treated with phosphate buffer solution (PBS). Histone group was treated with histone 50μg/mL for 1 hour. UFH 10 IU/mL and Y27632 10 uM were added 30 min before exposure to histones.Results: UFH attenuated histone-induced permeability changes of HPMECs. UFH reduced histone-induced syndecan-1 shedding and the depolymerization of Ace-tubulin and β-tubulin. UFH inhibited histone-induced decrease in syndecan-1 and Ace-tubulin. UFH inhibited histone-induced expression, re-distribution and secretion of HPA-1. UFH reduced histone-induced expression of ROCK-1 and phosphorylated myosin light-chain (p-MLC) in HPMECs.Conclusion: UFH protects the glycocalyx and endothelial barrier while inhibiting histone induced HPA expression, perinuclear distribution, and secretion, with the involvement of the ROCK pathway.Keywords: histone, unfractionated heparin, glycocalyx, heparanase, Rho-associated kinase