Screening differentially expressed genes and the pathogenesis in atopic dermatitis using bioinformatics.

Atopic dermatitis (AD) is a common chronic skin inflammation. It was to screen differentially expressed genes (DEGs) and related biological functional pathways in atopic dermatitis (AD) by bioinformatics methods, and to understand the pathogenesis of AD. gene chip datasets GSE120721 and GSE32924 in the public database NCBI Gene Expression Omnibus (GEO) were adopted. Differential expression analysis between the patient group and controls was performed by applying the zero-code differential expression analysis tool GEO2R, and a few DEGs were screened. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were carried out. In addition, the STRING online database was employed to predict the potential relationship among DEGs, the protein-protein interaction network (PPI) was drawn, and the module analysis of PPI was performed using the Cytoscape plugin MCODE. 233 DEGs were screened out, including 134 up-regulated genes and 99 down-regulated genes. GO analysis suggested that these DEGs were mainly involved in biological processes (BP), cellular components (CC), and molecular function (MF). KEGG analysis displayed that these DEGs were mainly involved in NF-kappa B signaling, cell cycle, T cell receptor signaling, and other pathways. PPI analysis indicated that there were complex interactions among DEGs, and module analysis further revealed the important roles of DEGs in regulating immune response, inflammatory response, and skin barrier function. The above findings provide a valuable reference for the development of new treatment options.

[Cloning, expression and purification of rabbit metallothionein-I gene in Escherichia coli].

The cDNA encoding the rabbit metallothionein-I was amplified by RT-PCR from the rabbit liver induced by cadmium and cloned into prokaryotic fusion expression vector pQE40. Then it was transformed into Escherichia coli M15. Positive expression clones were detected by colony blotting. Target protein solubility was determined by Western blotting analysis. The optimal induction condition of the level of protein expression with IPTG induction was established by SDS-PAGE electrophoresis and ImageMaster VDS software analysis. The fusion protein can be purified from lysates with Ni-NTA agarose. We found that the fusion protein with apparent molecular weight 32 KD existed in two ways: soluble and insoluble in Escherichia coli. After 1 mM IPTG induction, the level of expression of the fusion protein increased with the prolongation of induction time and reached a peak in 9 h by ImageMaster VDS software analysis, accounting for 57.4% of all the insoluble protein. The purified fusion protein was obtained by Ni-NTA affinity chromatography. This fusion protein can be used in further studies on the preparation of MT-I protein and development of protein product.