A Novel Protective Role Of Ginkgolide A On Pulmonary Microvascular Endothelial Cells Apoptosis Induced By LPS

Endotoxin or lipopolysaccharide (LPS) as the cell wall of Gram-negativebacteria, is one of the most common and main risk factors. it often causes a variety ofdiseases, mainly associated with vascular dysfunction. Such as Acute Lung Injury(ALI), pathological changes are mainly for the following aspects, the inflammatorycytokine released, structural damaged, number of red blood cells and alveolarinflammatory cell infiltrated and so on. However, Pulmonary MicrovascularEndothelial Cell (PMVEC) is the first damaged and apoptosis. Ginkgolide A(Ginkgolide A) as one of the main monomer component of Ginkgo biloba extract, ismainly for platelet activating factor antagonist, in addition, there is anti-free radical,anti-apoptosis, protecting vascular endothelium. However, whether Ginkgolide A caninhibit vascular endothelial cell apoptosis to ease ALI has not yet been reported, so westudy the biological effects of anti-vascular endothelial cell apoptosis of Ginkgolide Aboth in vivo and in vitro.Frist，we established a model of ALI in vivo and enzyme-linked immuno sorbentassay (ELISA) tested the the expression levels of inflammatory cytokinesIL-1β，TNF-α，IL-6in the BLAF，hematoxylin and eosin stain (HE stain) andterminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling(TUNEL) tested Lung tissue histology and vascular endothelial cell apoptosis usingthe right lung．The result showed Ginkgolide A significantly decreased the levels ofinflammatory cytokines IL-1β，TNF-α，IL-6(P<0.01or p<0.05)，up-regulated theLung tissue pathologic change and significantly decreased the number of vascularendothelial cell apoptosis induced by LPS in vivo．So it can protect the developmentof ALI induced by LPS．In vitro experiment study，DNA LADDER，fluorescence microscope，laser confocalmicroscope result showed the PMVEC treated with different concentrations of LPSappeared typical DNA ladder and apoptosis morphological changes． as for thecytoplasm condensed， the nuclear chromatin gathere， marginalized，cell nucleus cracked into pieces，produced apoptotic body and presented the concentrationdependence．we determined the LPS can induce PMVEC apoptosis．MTT，FlowCytometry (FCM)，results showed the Ginkgolide A for10μg/mL had no significantcytotoxic response of cells，and significantly increased the percentage of G2/M phasecompared with LPS group (p<0.05)．We future confirmed the promoting effect of cellproliferation．RT-PCR and Western Blotting results showed Ginkgolide A caused asignificantly up regulate compared with LPS group for the expression c-Myc andBcl-2mRNA．While there was no effect for the expression of c-Fos and c-JunmRNA．the protein of P-NFκB，P-IκB was significantly decreased and the protein ofBcl-2，IκB，NF-κB significantly increased (p<0.01or p<0.05)．it strengthened our ideathat Ginkgolide A within the scope of nontoxic can inhibit apoptosis of PMVEC andassociate with NF-κB signaling pathway．Above all，Ginkgoide A can significantly decrease the levels of inflammatorycytokines，up-regulate the Lung tissue pathologic change and inhibite the PulmonaryMicrovascular Endothelial Cells induced by LPS．The mechanism is associated withNF-κB signaling pathway．This will provide the experimental data and theoreticalbasis for antiapoptotic drugs researching and curing disease widely．...