ABSTRACT
Objective:To investigate the expression of long non-coding RNA metastasis associated lung adenocarcinoma transcript 1(lncRNA MALAT1) in bronchopulmonary dysplasia (BPD) of neonatal rats induced by hyperoxia and its effect on alveolar type 2 epithelial cells (AEC Ⅱ).Methods:The lung injury model of neonatal SD rats induced by hyperoxia(model group, n=50, inhaled oxygen concentration of 80%-85%) and the control group(inhaled air, n=50) were prepared.Lung tissue samples were taken and retained on days 1, 3, 7, 14 and 21, and the physiological and pathological changes of lung tissue were detected by paraffin-embedded sections and hematoxylin-eosin staining; The dynamic expression of lncRNA MALAT1 in lung tissue was detected by real-time fluorescent quantitative polymerase chain reaction; The dynamic expression of surfactant protein C(SPC) in lung tissue and AECⅡ was detected by Western blot.AECⅡ was extracted from lung tissue of normal newborn rats, and lncRNA MALAT1 was knocked down by siRNA.The cells were collected and Western blot as well as immunofluorescence were used to detect the changes of SPC. Results:The lung tissue of model group gradually became thickened with alveolar compartments, and the alveolar cavity was enlarged with the disappearance of alveolar spine and other pathological structural changes.Compared with the control group, there was no difference in the expression of lncRNA MALAT1 and SPC in the lung tissue from model group on days 1, 3( P>0.05), but the expression of lncRNA MALAT1 and SPC significantly increased on days 7, 14 and 21( P<0.05). When lncRNA MALAT1 was inhibited, SPC expression showed a decrease trend. Conclusion:Hyperoxia can lead to the stagnation of lung development in neonatal rats, and the structure and function of alveolar disorders are impaired.The expression of lncRNA MALAT1 is involved in the process of hyperoxia-induced BPD in neonatal rats.The increase of lncRNA MALAT1 may promote the proliferation of AECⅡ.
ABSTRACT
Objective:To investigate expression level of transcriptional co-activator with PDZ-binding motif(TAZ) in neonatal rats with chronic lung diseases induced by hyperoxia and explore its potential role in the disease.Methods:The model of high-oxygen-induced lung injury in neonatal rats was established by continuous inhalation of high-concentration oxygen.The rats in experimental group inhaled 85% oxygen, while the rats in control group inhaled air.The lung tissues were collected at the 1st, 3rd, 7th, 14th and 21st day, and the lung tissue sections were stained with hematoxylin and eosin staining to observe the pathological changes of the lung.In addition, the dynamic expressions of TAZ, surfactant protein C(SPC) and aquaporin-5(AQP5) in lung tissue were detected by real-time PCR, western blot and immunohistochemistry staining.Results:In the experimental group, with the prolongation of oxygen inhalation time, we found that the alveolar cavity increased, the number decreased, the alveolar septum thickened, and the alveolar structure was simplified.Compared with the control group, there was no difference in TAZ, SPC and AQP5 expression at 1st and 3rd days in the lung tissue in the experimental group( P>0.05). However, at 7, 14 and 21 days, the expression of TAZ in mRNA and protein level in lung tissue in experimental group decreased significantly, and the expression of SPC in mRNA and protein level increased significantly, while the expression of AQP5 in mRNA and protein level decreased, the differences were all statistically significant( P<0.05). Conclusion:Hyperoxia can cause alveolar structure disorder and pulmonary arrested development in neonatal rat.The expression levels of SPC and AQP5 show that the injury of type Ⅰ alveolar epithelial cells (AEC Ⅰ) is severe.Although the number of type Ⅱ alveolar epithelial cells (AEC Ⅱ) increased, but its differentiation capacity decreased obviously.The decrease of TAZ expression may cause AEC Ⅱ lose the function of differentiation into AEC Ⅰ.
ABSTRACT
Objective To investigate the roles of a epoprostenol(PGI2) analog (Iloprost) in regulating the differentiation of CD4+ T cells to Treg cells and the possible mechanism.Methods Naǐve CD4+ T cells were isolated from human peripheral blood samples by using the magnetic-activated cell sorting (MACS) and then cultured under Treg-polarizing condition.The percentages of Treg cells and the expression of Foxp3 at mRNA level were respectively measured by using flow cytometry and RT-PCR for evaluation the effects of Iloprost on the differentiation of CD4+ T cells to Treg cells.The cAMP accumulation assay was used to detect the level of intracellular cAMP.Flow cytometry analysis was performed to detect the phosphorylation of signal transducer and activator of transcription 5 (STAT5).Results lloprost decreased the percentage of Treg cells and inhibited the expression of Foxp3 at mRNA level in a dose dependent manner (P＜0.05).However,the inhibitory effects of Iloprost were weakened when IP receptors were blocked by IP antagonist (CAY10449).A six-fold increase in the levels of intracellular cAMP in Treg cells was induced by Iloprost (P＜0.05) and a similar effect could be achieved by using a cAMP agonist,db-cAMP (P＞0.05).H-89,a protein kinase A inhibitor,inhibited the Iloprost-induced expression of cAMP in Treg cells.Moreover,Iloprost inhibited the IL-2 mediated phosphorylation of STAT5 (P＜0.05) and a similar effect could be achieved by using db-cAMP (P＞0.05).The Iloprost-mediated down-regulation of pSTAT5 was blocked by using H-89.Conclusion PGI2 could activate the cAMP-PKA signaling pathway by binding to the IP receptor,resulting in inhibited phosphorylation of STAT5 and suppressed differentiation of naǐve CD4+ T cells to Treg cells.