Expression Of Endoplasmic Reticulum Stress-Related Factor And Effect Of Insulin-Like Growth Factor-â…  In Hyperoxia-Induced A549Cells

Objective:Endoplasmic reticulum stress is considered to be an important stage in the development of hyperoxia induced lung tissue injured. Here, we determine the contri-bution of IGF-Ⅰ induced endoplasmic reticulum stress apoptotic factor CHOP, caspase-3expression, as well as the effect on morphological changes in A549cells exposed to hyperoxic conditions.Method:The cultured A549cells were divided into five groups:group Ⅰ:normoxia, group Ⅱ: hyperoxia, group Ⅲ:hyperoxia+IGF-Ⅰ (1ng/ml) dose, group Ⅳ:hyper-oxia+IGF-Ⅰ (10ng/ml) dose, group Ⅴ:hyperoxia+IGF-Ⅰ (100ng/ml) dose. Each group of the A549cells was placed in a CO2incubator thermostat cells cultured for24hours. Then observe cell growth, when cells overgrow to50%, added different con-centration of IGF-Ⅰ. Group Ⅰ (normoxia group):A549cells were incubated in10%FBS-containing DMEM medium and placed in5%CO2,37℃cell culture incubator. Group Ⅱ (hyperoxia group):A549cells were incubated in10%FBS-containing DMEM medium and Pass into3L/min containing5%CO2,5%N2and90%oxygen nitrox In, placed in37℃cell culture incubator. Drug treatment group:Given A540cells in different concentrations of IGF-1treatment and Pass into3L/min containing5%CO2,5%N2and90%oxygen nitrox1h, placed in37℃cell culture incubator. Apoptosis morphological changes were observed by inverted microscope; cell viability between different groups was measured by MIT; using DAPI staining observed apoptotic nuclei in each group; to detect the expression of endoplasmic reticulum apoptotic factor CHOP and Caspase-3by western-blotResult:The morphological results showed that hyperoxia group compared with the normal group the surviving cells was significantly decreased, cell shrinkage smaller, round, typical apoptotic phenomena surrounding cell separate-on After treatment with different doses of IGF-I, apoptosis was partially reversed. The role of high oxygen+IGF-Ⅰ (100ng/ml) inhibited the cell apoptosis was the most significant MTT experiments showed that cell viability between different groups there are significant differences. Hyperoxia decreased cell viability, and different doses of IGF-Ⅰ treated A549cells the survival rate increased, high oxygen+IGF-Ⅰ (100ng/ml) increased cell survival most significant DAPI staining results showed that more fluorescently labeled nuclei after high-oxygen treatment, fluorescently labeled nuclei gradually reduced after treated with different doses of IGF-Ⅰ. High oxygen+IGF-Ⅰ (100ng/ml) group difference was significant Western-blot showed that hyperoxia treatment endoplasmic reticulum stress-related apoptosis factor CHOP, Caspase-3expression was significantly increased. Different doses of IGF-Ⅰ treatment, CHOP and Caspase-3expression were reduced, High oxygen+IGF-Ⅰ (100ng/ml) group reduced was significantConclusion:1. IGF-Ⅰ has a protective effect on A549cells exposed to high concentrations of oxygen environment2. IGF-Ⅰ can inhibit apoptosis of A549cells in conditions of high concentrations of oxygen Different concentrations of IGF-Ⅰ in the inhibition of apoptosis may have a two-way effect, the strongest inhibition of apoptosis is IGF-Ⅰ in100ng/ml doses.3. Hyperoxia-induced A549cells endoplasmic reticulum stress, endoplasmic reticulum stress-related apoptotic factor CHOP, Caspase-3expression were increased4. IGF-Ⅰ inhibitied the expression of endoplasmic reticulum stress-related apoptotic factor CHOP, Caspase-3under the hyperoxia condition, IGF-Ⅰ in the inhibition of apoptosis plays an important role.