Journal Article

Genetic deletion of Sphk2 confers protection against Pseudomonas aeruginosa mediated differential expression of genes related to virulent infection and inflammation in mouse lung

Maienschein-Cline, Mark, Natarajan, Viswanathan, Madduri, Ravi, Harijith, Anantha, Arbieva, Zarema, Hu, Hong, Fu, Panfeng, Krishnan, Yashaswin, Ebenezer, David L., Jung, Segun

2019

Overview

Background Pseudomonas aeruginosa ( PA ) is an opportunistic Gram-negative bacterium that causes serious life threatening and nosocomial infections including pneumonia. PA has the ability to alter host genome to facilitate its invasion, thus increasing the virulence of the organism. Sphingosine-1- phosphate (S1P), a bioactive lipid, is known to play a key role in facilitating infection. Sphingosine kinases (SPHK) 1&2 phosphorylate sphingosine to generate S1P in mammalian cells. We reported earlier that Sphk2 −/− mice offered significant protection against lung inflammation, compared to wild type (WT) animals. Therefore, we profiled the differential expression of genes between the protected group of Sphk2 −/− and the wild type controls to better understand the underlying protective mechanisms related to the Sphk2 deletion in lung inflammatory injury. Whole transcriptome shotgun sequencing (RNA-Seq) was performed on mouse lung tissue using NextSeq 500 sequencing system. Results Two-way analysis of variance (ANOVA) analysis was performed and differentially expressed genes following PA infection were identified using whole transcriptome of Sphk2 −/− mice and their WT counterparts. Pathway (PW) enrichment analyses of the RNA seq data identified several signaling pathways that are likely to play a crucial role in pneumonia caused by PA such as those involved in: 1. Immune response to PA infection and NF-κB signal transduction; 2. PKC signal transduction; 3. Impact on epigenetic regulation; 4. Epithelial sodium channel pathway; 5. Mucin expression; and 6. Bacterial infection related pathways. Our genomic data suggests a potential role for SPHK2 in PA -induced pneumonia through elevated expression of inflammatory genes in lung tissue. Further, validation by RT-PCR on 10 differentially expressed genes showed 100% concordance in terms of vectoral changes as well as significant fold change. Conclusion Using Sphk2 −/− mice and differential gene expression analysis, we have shown here that S1P/SPHK2 signaling could play a key role in promoting PA pneumonia. The identified genes promote inflammation and suppress others that naturally inhibit inflammation and host defense. Thus, targeting SPHK2/S1P signaling in PA -induced lung inflammation could serve as a potential therapy to combat PA -induced pneumonia.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,Springer,BMC
• Subject: Analysis of Variance / Animal Genetics and Genomics / Animal tissues / Animals / Bacterial diseases / Bacterial pneumonia / BASIC BIOLOGICAL SCIENCES / Biomedical and Life Sciences / Cells / Cellular signal transduction / Chronic obstructive pulmonary disease / Clonal deletion / Comparative analysis / Cystic fibrosis / Disease Models, Animal / Drug resistance / Epigenetic inheritance / Experiments / Female / Gene Deletion / Gene expression / Gene Expression Profiling - methods / Gene Expression Regulation / Gene Profiling / Gene Regulatory Networks / Gene sequencing / Generalized linear models / Genes / Genetic research / Genomes / Genomics / Genomics, bacterial resistance / Health aspects / High-Throughput Nucleotide Sequencing / Human and rodent genomics / Hybridization / Immune response / Infections / Inflammation / Kinases / Labeling / Life Sciences / Lipids / Lung - immunology / Lung - microbiology / Lung infection / Lungs / Mammalian cells / Membrane lipids / Mice / Microarrays / Microbial Genetics and Genomics / Mucin / NF-κB protein / Nosocomial infection / Phosphates / Phosphotransferases (Alcohol Group Acceptor) - genetics / Plant Genetics and Genomics / Pneumonia / Polymerase chain reaction / Protein kinase C / Proteomics / Pseudomonas aeruginosa / Pseudomonas aeruginosa - pathogenicity / Pseudomonas Infections - genetics / Pseudomonas Infections - immunology / Pseudomonas Infections - prevention & control / Quality control / Research Article / Resistance to Infection / Ribonucleic acid / RNA / RNA sequencing / RNA-Seq / Sheep / Signal transduction / Signaling / Sphingolipids / Sphingosine / Sphingosine kinase 2 / Variance analysis / Virulence / Virulence (Microbiology)