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Objective:To evaluate whether FOXO4-DRI could reverse radiation-induced pulmonary fibrosis (RIPF) and to explore the underlying mechanism.Methods:C57BL/6 mice were randomly divided into 4 groups: control, FOXO4-DRI, radiation, and radiation+ FOXO4-DRI. Mice in radiation or radiation+ FOXO4-DRI groups received 17 Gy X-ray radiation on the right side of the whole chest. Mice in FOXO4-DRI and radiation+ FOXO4-DRI groups were injected with FOXO4-DRI intraperitoneally at 16 and 20 weeks after irradiation, respectively. The right lungs were collected at 24 weeks after irradiation and subjected to HE staining and Masson trichrome staining to observe the morphological changes and collagen deposition. Immunohistochemistry was used to evaluate the expressions of col1α1 and α-SMA in lung tissues. β-gal staining was used to observe senescent cells. The level of reactive oxygen species in lung tissue was detected. The expressions of P21, P16 Ink4a and senescence-associated secretory phenotype (SASP) mRNA were detected by qRT-PCR, and the expression of related proteins were assessed by Western blot. Results:FOXO4-DRI reduced collagen deposition ( t=6.18, P<0.05), down-regulated the expression of col1α1 and α-SMA ( t=4.69, 3.20, P<0.05), and reduced the number of β-gal positive cells ( t=6.09, P<0.05) in the lung tissue of RIPF mice. FOXO4-DRI also down-regulated the gene and protein expressions of P21 and P16 Ink4a ( t=5.31, 3.32 and 4.77, 3.37, P<0.05) and inhibited the expressions of SASP genes IL-1α, IL-1β, TNF-α and MMP2 ( t=4.36, 4.84, 4.47, 3.82, P<0.05), reduced reactive oxygen species ( t=2.84, P<0.05), and promoted the activation of p-AKT and p-PI3K proteins ( t=-7.13, -12.61, P< 0.05) in the lung tissue of RIPF mice. Conclusions:FOXO4-DRI reverses RIPF by activating the PI3K/AKT signaling pathway, reducing oxidative stress and inhibiting cellular senescence.
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Objective@#To explore the effects of FOXO4 D-retro-inverso peptide (FOXO4-DRI) on the radiosensitivity of non-small cell lung cancer (NSCLC) cells.@*Methods@#To detect the effect of FOXO4-DRI on NSCLC cells, H460 and A549 human lung cancer cells were divided into four groups, including untreated control, FOXO4-DRI, γ-ray irradiation and FOXO4-DRI + γ-ray groups. A sigle dose rate of 0.99 Gy γ-rays was used for radiation. H460 cells were administered with 6 μmol/L FOXO4-DRI and A549 cells were adiminstered with 30 μmol/L FOXO4-DRI at 10 min before radiation. Cell viability and survival were detected by CCK-8 assay and colony formation assay, respectively. Cell migration was detected by wound healing assay. Apoptosis and cell cycle arrest were detected with flow cytometry.@*Results@#FOXO4-DRI inhibited growth of H460 and A549 cells (t=1.06-50.75, P<0.05), and decreased cell mobility (t=33.37-139.10, P<0.05) and colony formation (t=5.20-93.48, P<0.05). FOXO4-DRI also increased apoptosis (t=2.95-42.00, P<0.05) and caused a cell cycle arrest at G0/G1 phase accompanied with a decreased proportion of G2/M phase (t=3.50-31.59, P<0.05). Furthermore, FOXO4-DRI increased radiosensitivity of both H460 cells and A549 cells (t=2.94-23.40, P<0.05), caused a Further Decrease of radiation-mediated mobility (t=5.25, 7.56, P<0.05) and colony formation (t=8.43-34.00, P<0.05) and a more increase of radiation-induced apoptosis (t=9.20-11.52, P<0.05). FOXO4-DRI also further decreased the proportion of G2/M phase cells but increased the proportion of S phase cells (t=3.85-17.62, P<0.05).@*Conclusion@#FOXO4-DRI increases radiosensitivity of NSCLC cells by inducing apoptosis and suppressing cell proliferation.
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Objective To explore the effects of FOXO4 D-retro-inverso peptide (FOXO4-DRI)on the radiosensitivity of non-small cell lung cancer (NSCLC) cells.Methods To detect the effect of FOXO4-DRI on NSCLC cells,H460 and A549 human lung cancer cells were divided into four groups,including untreated control,FOXO4-DRI,γ-ray irradiation and FOXO4-DRI + γ-ray groups.A sigle dose rate of 0.99 Gy γ-rays was used for radiation.H460 cells were administered with 6 μmol/L FOXO4-DRI and A549 cells were adiminstered with 30 μmol/L FOXO4-DRI at 10 min before radiation.Cell viability and survival were detected by CCK-8 assay and colony formation assay,respectively.Cell migration was detected by wound healing assay.Apoptosis and cell cycle arrest were detected with flow cytometry.Results FOXO4-DRI inhibited growth of H460 and A549 cells (t =1.06-50.75,P＜ 0.05),and decreased cell mobility (t =33.37-139.10,P＜0.05) and colony formation (t =5.20-93.48,P＜0.05).FOXO4-DRI also increased apoptosis (t=2.95-42.00,P＜0.05) and caused a cell cycle arrest at G0/G1 phase accompanied with a decreased proportion of G2/M phase (t =3.50-3 1.59,P＜0.05).Furthermore,FOXO4-DRI increased radiosensitivity of both H460 cells and A549 cells (t =2.94-23.40,P＜0.05),caused a Further Decrease of radiation-mediated mobility (t =5.25,7.56,P＜0.05) and colony formation (t =8.43-34.00,P＜ 0.05) and a more increase of radiation-induced apoptosis (t =9.20-11.52,P ＜0.05).FOXO4-DRI also further decreased the proportion of G2/M phase cells but increased the proportion of S phase cells (t =3.85-17.62,P ＜ 0.05).Conclusion FOXO4-DRI increases radiosensitivity of NSCLC cells by inducing apoptosis and suppressing cell proliferation.