Effect of neuropeptide substance P on the type Ⅱ alveolar epithelial cells exposed to hyperxia and relationship with extracellular signal-regulated protein kinase signal transduction pathway
HUANG Bo
LI Qing
YE Mei
YANG Hai-yan
KUANG Feng-wu
XU Feng
Abstract：Objective To investigate the regulatory mechanism of neuropeptide substance P(SP) in lung injury induced by hyperxia and the relationship between SP and extracellular signal-regulated protein kinase (ERK)signal transduction pathway. Methods The primary premature rats type Ⅱ alveolar epithelial cells (AEC Ⅱ) were isolated and purified.They were randomly divided into 3 groups, including air group, hyperxia group and SP intervention group. Air(21% oxygen) group and hyperxia(95% oxygen) group were placed in the closed oxygen chamber for 48 h respectively. With regard to SP intervention group, SP(1×10~(-6)mol/L) was added before the exposure.As following, the group was exposed to 21% and 95% oxygen for 48 h respectively. Sample of each group was obtained at 12, 24 and 48 h and morphologic change of AEC Ⅱ was observed under electron microscope.MTT and flow cytometry was employed to detect the growth rate and apoptosis rate respectively.Dynamic change of phosphorylated ERK was determined using Western blot.Results Growth rate of AEC Ⅱ in hyperxia group decreased signifcantly and the apoptosis rate increased remarkbly compared to air group.The growth rate increased notablely and the apoptosis rate decreased obviously after the intervention of SP.Meanwhile, the morphologic injure improved signifcantly.Hyperxia stimulation could result in activation of ERK phosphorylation, and the expression of phosphorylated ERK increased remarkbly in the impaired AEC Ⅱ induced by hyperxia.Nevertheless, the expression of ERK increased notably after the intervention of SP. Conclusion SP could promote the proliferation and inhibit the apoptosis of AEC Ⅱ exposed to hyperxia via suppressing activation of ERK signal and then inhibiting the apoptosis, which has a protective effect on AEC Ⅱ under oxidative stress.
Keywords：substance Phyperxiatype Ⅱ alveolar epithelial cellssignal-regulated protein kinase
Publication Date：2009-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 959-963 )