HDL Attenuate Inflammation Induced By LPS And Promote Reviving Of Alveolar Epithelial Cells

Objective :High density lipoprotein(HDL)have a series of functions to protect cardiovascular.However,many studies review HDL also has some interesting features to inhibit releasing of inflammatory cytokines,maintain type ? alveolar epithelial cells activity,promote producing of pulmonary surfactant.Under inflammatory conditions,injured alveolar cells release inflammatory cytokines such as TNF-?,IL-?,recruiting neutrophils,reviving macrophages to aggravate cell damage.During process of damage and repair,MAPK,a potential signal path,may play a major role to promotes alveolar cells proliferation and migration.To investigate the effect and mechanism of high density lipoprotein(HDL)on type ? alveolar epithelial cells during inflammation state.Methods :Separating the original generation of type ? alveolar epithelial cells in rats,and treated cells with PBS/LPS/HDL/HDL+LPS.To observe the function of type ? alveolar epithelial cells with Brdu proliferation assay,transwell and wound healing experiments.In addition,western blot detected the expression of TP-binding cassette transporter A1(ABCA1),cystic fibrosis transmembrane conductance regulator(CFTR)and the phosphorylation of AKT/ERK/MAPK.Enzyme-linked immunosorbent assay(ELISA)tested the secretion of TNF-?/IL-?/IL-6.Results: HDL promoted the proliferation(HDL+ LPS vs.LPS,1.31±0.17 vs 1.12±0.08,17% p<0.001)and migration(wounding healing:93%,HDL+ LPS vs.LPS,162.6 ±15.43 vs 64.1±12.18,93%,p<0.001;transwell migration HDL+ LPS vs.LPS,332.2±37.66 vs 172.1±15.07,154%,p<0.001)of type ? alveolar epithelial cells.Furthermore,HDL increased the phosphorylation of MAPK,but not AKT/ERK.And HDL decreased the secretion of TNF-?(HDL+ LPS vs.LPS,0.10±0.008 vs0.19±0.017,46%,p<0.01)and IL-?(HDL+ LPS vs.LPS,0.08±0.004 vs 0.10±0.008,45%,p<0.001),but not IL-6.In addition,HDL up-regulated the expression of ABCAI(HDL vs.CON,1.24 ± 0.04 vs 0.62 ± 0.05,99%,p<0.001)and down-regulated the expression of CFTR(HDL vs.CON,1.40±0.08 vs 2.40±0.09,25%,p<0.05)in type ? alveolar epithelial cells.Conclusions : HDL increases the phosphorylation of MAPK,which promotes the proliferation and migration of type ? alveolar epithelial cells.And it decreased the secretion of TNF-?/IL-? and the expression of CFTR.All these suggest that HDL plays an important role in anti-inflammatory effect in inflammation state of lung.