Effects of heat stress and the serum of mice suffering from heat stroke on adherent ability of monocytes to pulmonary microvascular endothelial cells in vitro

Liu Yanan; Xu Qiulin; Guo Xiaohua; Zhou Gengbiao; Wang Zhenglian; Lu Jiefu; Qiu Junming; Su Lei

doi:10.3969/j.issn.1672-8521.2014.03.001

Abstract：Objective:To investigate the effect of heat stress and the serum of mice suffering from heat stroke on capacity of pulmonary microvascular endothelial cells (PMVECs)to express vascular cell adhesion molecule-1 (VCAM-1)and intercellular adhesion molecule-1 (ICAM-1),and adherent capacity of PMVECs to monocytes in vitro. Methods:PMVECs were isolated from neonatal mice by the method of secondary magnetic bead sorting. The morphology of PMVECs was observed under light microscope and identified by VE-Cadherin and Ⅷ factor stai-ning. PMVECs were randomly divided into 3 groups,including cells undergoing normal culture (37 ℃,as normal control),42 ℃ heat stress for 2 hours,and co-culture with serum of mice with heat stroke. Twenty-four hours later,total RNA was extracted,the quantitative PCR and Western blotting were used for the determination of mRNA and protein expressions of VCAM-1 and ICAM-1. The adherent capacity of PMVECs to monocytes was observed with fluorescence microscopy. Results:The PMVEC displayed typical"cobblestone"morphology under light microscopy,and they were positive with both VE-cadherin staining at cell-cell j unctions and Ⅷ factor,thus they were identified as endothelial cells. Compared to normal control group,the VCAM-1 and ICAM-1 mRNA and protein levels were decreased in heat stress group (P<0.05),but increased after stimulation of 10% serum of mice with heat stroke (P<0.01).Compared to the normal control group,the number of adherent THP-1 cells was similar in heat stress group,but the number of THP-1 cells was significantly increased in serum stimulation group,show-ing that the adherent capacity of PMVECs to monocyte was enhanced. Conclusions:Heat stress did not upregulate the ex-pression of endothelial cell adhesive molecules of PMVECs. But stimulation of serum of mice with heat stroke significantly up-regulate the expression of endothelial cell adhesion molecules,facilitating adhesion of monocytes,which produce or ag-gravate acute lung inj ury in heat stroke.