ABSTRACT
Objective·To investigate the effects of interleukin-1β (IL-1β) on neonatal rat alveolar arrest induced by intra-amniotic injection of lipopolysaccharide (LPS). Methods·A neonatal SD rat model of bronchopulmonary dysplasia (BPD) was constructed by intra-amniotic injection of LPS in pregnant rats. The pregnant rats (E19) were randomly assigned to Saline group, LPS group and LPS+anti-IL-1β group. The lungs of the neonatal rats were randomly collected 1, 3 and 7 days after birth. Pathological changes in the lungs were observed by hematoxylin-eosin (H-E) staining, and expression of IL-1β mRNA and protein was detected by real-time PCR and ELISA, respectively. Rat bone marrow derived primary macrophage was cultured in vitro, and given LPS intervention, then genes related with IL-1β were detected through whole transcriptome sequencing. Results·Compared with the Saline group, the alveolar counts and secondary septa counts significantly decreased, and mean liner intercept significantly increased in LPS group. Moreover, the expression of IL-1β mRNA and protein in lungs significantly increased in LPS group. The LPS-induced pathological changes of lung tissues in neonatal rats were improved by anti-IL-1β. LPS could up-regulate the expression of genes including Gbp5, Ccl3, Nod2, Ccr5, Mefv, Casp4 and Ifnar1, but down-regulate Lgals9 and Gstp1. Among these genes Gbp5, Ccl3, Nod2, Ccr5, Casp4, Ifnar1 and Lgals9 could positively regulate IL-1βproduction. Conclusion·LPS can induce alveolar arrest through up-regulating the expression of IL-1β in macrophages in neonatal rat BPD model. Whole transcriptome sequencing reveals that LPS can regulate the expression of IL-1β in macrophages through several paths.
ABSTRACT
Objective To synthesize a photoacoustic contrast agent loaded with gold nanorod and liquid perflurocarbon which was used to observe its photoacoustic imaging in vitro,and then investigate the variation of the photoacoustic signal during and after the vaporization.Methods The PLGA nanoparticle (GNP)loaded with gold nanorod(GNR) and liquid perflurocarbon was synthesized via double emulsion technology.The experiments were divided into three groups:1)GNP group:PLGA nanoparticle loaded with gold nanorod and liquid perflurocarbon; 2) GNR group:gold nanorod ; 3) control group:PLGA nanoparticle unloaded with gold nanorod.A pulsed laser system was used to trigger the three samples.The photoacoustic image and time-signal intensity kinetics were acquired by the photoacoustic microscope.The optical microscope was used to observe the image after the vaporization.Results The gold nanoparticle was successfully prepared,the average size of the gold nanoparticle was 504.9 nm.after triggered by the pulsed laser system,the vaporized image of the GNP group could be observed by the optical microscope.The photoacoustic signal was detected in both GNP and GNR groups,and the signal intensity increased along with the concentration of the GNR.However,the photoacoustic signal of PLGA group was not detected.The photoacoustic signal kinetics of GNP group showed a descending trend from high signal amplitude to steadystate.The GNR group photoacoustic signal kinetics only showed a steady-state signal amplitude.Conclusions The PLGA nanoparticle loaded with gold nanorod and liquid perflurocarbon emerged a phase transient which produces a strong photoacoustic signal after triggered by pulsed laser system.This kind of phenomenon leads the nanoparticle to be a better photoacoustic contrast agent and lays a foundation for in vivo research and photothermal therapy in vivo.