Cdc42 regulates LPS-induced proliferation of primary pulmonary microvascular endothelial cells via ERK pathway

Background: After stimulation due to injury, cell division cycle protein 42 (Cdc42) restores and enhances barrier functions by strengthening intercellular adherens junctions; however, its influence on cell proliferation after injury remains unknown. Objective: In this study, we sought to investigate the effect of stimulation using small doses of lipopolysaccharide (LPS) on the proliferation of pulmonary microvascular endothelial cells (PMVECs). Methods: We stimulated PMVECs with different doses of LPS and evaluated the effects on cell proliferation. We also constructed a primary gene-knockout cell line lacking Cdc42 to verify the role of Cdc42 in regulating the proliferation of PMVECs that were stimulated using LPS and to explore related signaling pathways. Results: Stimulating PMVECs with small doses of LPS increased proliferation. Cdc42 is involved in regulating this process, which was mediated by the extracellular regulated protein kinase (ERK) pathway. Conclusions: Cdc42 plays a role in regulating the proliferation of PMVECs stimulated with small doses of LPS, and this regulation involves the ERIC pathway. (C) 2016 Elsevier Inc. All rights reserved.