[Exploring and bioinformatics analysis of differentially expressed genes in bronchial asthma]

Objective: To screen core differentially expressed genes of bronchial asthma and conduct bioinformatics analysis. Methods: Macrophage microarray data GSE22528 from asthma patients were downloaded from gene expression database (GEO). The dataset included transcriptome information from 10 human alveolar lavage fluid samples, and five of them were from allergic asthmatic subjects and five from control subjects. Differential expression genes (DEGs) were screened by R 4.0.4 software. Gene ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed to select DEGs using DAVID 6.8 database. Protein interaction network (PPI) was constructed from DEGs encoded proteins using STRING online database. Cytoscape software was used to construct core modules and determine core DEGs. Results: Alveolar lavage fluid samples were all collected from Caucasian Canadians, with age range as (20, 37) and (18, 36) years, respectively, including 3 males for each group. In asthmatic patients, 449 genes were up-regulated and 47 down-regulated. GO analysis showed that the up-regulated genes in asthmatic patients were mainly involved in biological processes such as response to folded proteins, and the molecular function was focused on binding of folded proteins and growth factors. Down-regulated genes were mainly involved in biological processes such as histone deacetylation and ubiquitin-mediated protein degradation, and their molecular functions focused on histone deacetylation activity. KEGG pathway enrichment analysis showed that pathways were mainly enriched by up-regulation genes, involving Hippo signaling pathway, hypertrophic cardiomyopathy, estrogen signaling pathway, arrhythmogenic right ventricular cardiomyopathy, basal cell carcinoma, neuro-activated receptor ligand interaction, dilated cardiomyopathy and adhesion and connection signaling pathways. Two core modules were obtained by PPI analysis, and 14 core DEGs were screened out. They were pro-melanin concentrating hormone (PMCH), prepronociceptin (PNOC), Sphingosinol-1-phosphate receptor 2 (S1PR2), Sphingosinol-1-phosphate receptor 5 (S1PR5), CC-type chemokine ligand 21 (CCL21), Kelch-like protein 25 (KLHL25), ubiquitin binding enzyme E2V2 (UBE2V2), F-box protein 17 (FBXO17), taste receptor type 2 member 3 (TAS2R3), somatostatin receptor 2 (SSTR2), metabolic glutamate receptor 2 (GRM2), Lister E3 ubiquitin protein ligase 1 (LTN1), LIM domain specific protein 7 (LMO7) and ring finger protein 19A gene(RNF19A), in which LTN1 and UBE2V2 were down-regulated and the rest were up-regulated. Conclusion: DEGs was found in macrophages of asthmatic and control individuals. PMCH, PNOC, S1PR2, S1PR5 and CCL21 might be the core genes in the pathological process of asthma.

[Human bone marrow mesenchymal stem cells improve steroid resistance of human airway epithelial BEAS-2B cells in vitro]

Objective: To explore the effect of human bone marrow mesenchymal stem cells(MSC) on the steroid resistance of human airway epithelial cells. Methods: Ovalbumin (OVA)/lipopolysaccharide (LPS) were used to construct steroid resistant BEAS-2B cells, which were then co-cultured with MSC. Groups were set as follows: blank group, model group, Glucocorticoid group, MSC group, MSC+Glucocorticoid group (MSC+bud group). The expression of interleukin (IL)-8 in the cell supernatant was detected by enzyme-linked immunosorbent assay (ELISA); the expression of reactive oxygen species (ROS) in the cells was detected by flow cytometry; the expression of glucocorticoid receptor α (GRα) and histone deacetylase 2 (HDAC2) protein in the cell was detected by Western blotting; and the expression of GRα and HDAC2 mRNA was detected by reverse transcription-polymerase chain reaction (RTPCR). Results: The expression level of IL-8 in the MSC group was significantly lower than that in the Glucocorticoid group (31.7±0.7 vs. 49.8±3.6, P<0.01). The expression of ROS in the MSC group was significantly lower than that in the Glucocorticoid group (2754±154 vs.4624±228, P<0.05). The expression level of HDAC2 mRNA in the MSC group was significantly higher than that in the Glucocorticoid group(1.749±0.005 vs. 1.283±0.098, P<0.05). The expression level of GRα mRNA in the MSC group was significantly higher than that in the Glucocorticoid group (1.623±0.079 vs.1.047±0.220, P<0.01). The expression of HDAC2 protein in the MSC group was significantly higher than that in the Glucocorticoid group (1.067±0.100 vs. 0.620±0.083, P<0.01). The expression of GRα protein in the MSC group was significantly higher than that in the Glucocorticoid group (0.834±0.053 vs. 0.579±0.017, P<0.01). ROS was positively correlated with the IL-8 expression (r=0.796, P<0.01) and negatively correlated with the HDAC2 and GRα mRNA expression (r=-0.893 3, P<0.01; r=0.931 4, P<0.01, respectively), as well as the HDAC2 and GRα Protein expression (r=-0.929 5, P<0.01;r=-0.864 3, P<0.01, respectively). Conclusions: Human MSC can improve steroid resistance of airway epithelial cells in an exocrine manner. The mechanism may be related to the down-regulation of ROS and up-regulation of HDAC2, which lead to GRα overexpression. In addition, MSC may improve the steroid resistance by reducing the expression of IL-8.

Preparation and mechanical property of poly(ε-caprolactone)-matrix composites containing nano-apatite fillers modified by silane coupling agents

This study aims to improve the tensile strength and elastic modulus of nano-apatite/poly(ε-caprolactone) composites by silane-modification of the nano-apatite fillers. Three silane coupling agents were used to modify the surfaces of nano-apatite particles and composites of silanized apatite and PCL were prepared by a technique incorporating solvent dispersion, melting-blend and hot-pressing. The results showed that the silane coupling agents successfully modified the surfaces of nano-apatite fillers, and the crystallization temperatures of the silanized apatite/PCL composites were the higher than that of the non-silanized control material, although the melting temperature of the composites remained almost unaffected by silanization. The ultimate tensile strength and elastic modulus of the silanized composites reached 22.60 MPa and 1.76 GPa, as a result of the improved interfacial bonding and uniform dispersion of nano-apatite fillers. This study shows that the processing technique and silanization of nano-apatite particles can effectively improve the tensile strength and elastic modulus of nano-apatite/PCL composites.