Maternal Oxycodone Treatment Causes Pathophysiological Changes in the Mouse Placenta
Purpose: The goals of this study are to examine how maternal exposure to oxycodone affects the global transcriptome and histological structure of the mouse placenta at 12.5 dpc of pregnancy.retinal transcriptome profiling (RNA-seq) to microarray and quantitative reverse transcription polymerase chain reaction (qRT–PCR) methods and to evaluate protocols for optimal high-throughput data analysis Methods: A high throughput RNA sequencing method was used to examine the global transcriptomic changes affected by oxycodone in male and female conceptuses. Histomorphometrics were used to assess the various regions of the placenta, namely the labyrinth, spongiotrophoblast, and parietal trophoblast giant cell (pTGC) region. The open-sourced software, weighted correlation network analysis (WGCNA) was used to link gene expression changes and histological (phenotypic) changes. Results: Using an optimized data analysis workflow, we mapped over 40 million sequence reads per sample to the mouse genome (build grcm38). An average of 95.6% of reads (38.7 million) was mapped with HISAT2 workflow. We identified 12,138 transcripts in the placenta of saline control and oxycodone mice with featureCounts workflow. One hundred eighty-eight transcripts showed differential expression between the OXY male vs. CTL male placenta, with a log2Foldchange =1 and p value <0.05. Fifty-eight transcripts showed differential expression between the OXY female vs. CTL female placenta, with a log2Foldchange =1 and p value <0.05. Hierarchical clustering of differentially expressed genes uncovered several genes that may contribute to placenta function. Conclusions: Our study represents the first detailed analysis of placental transcriptomes in oxycodone-exposed mice, with biologic replicates, generated by RNA-seq technology. The data analysis workflows reported here should provide a framework for comparative investigations of expression profiles. We conclude that oxycodone exposure changed transcriptome characterization and these changes were associated with placenta histological features. Overall design: Placental RNA profiles at 12.5 embryo day old in Control and Oxcodone exposed mice