Analyses of circRNA and mRNA profiles in the submandibular gland in hypertension.

The aim of this study was to elucidate the roles played by circular RNAs (circRNAs) in the mechanism underlying submandibular gland (SMG) dysfunction in hypertension. We employed RNA-seq to analyze the circRNA and mRNA expression profiles of SMGs. Seventy-five differentially expressed (DE) circRNAs and 691 DE mRNAs were determined to be significantly altered in spontaneously hypertensive rats. Altered mRNAs were primarily related to the immune system and immune response. Eight circRNAs were selected for further analysis. Cell adhesion molecules were determined to be the most strongly enriched pathway through analysis of DE mRNAs, the coding noncoding gene co-expression (CNC) network and the competitive endogenous RNA (ceRNA) network. The salivary secretion pathway was observed to be notably enriched through analysis of the ceRNA network. These results suggest that the crosstalk among circRNAs may play a crucial role in the development of SMG dysfunction in hypertension.

Identification of circRNA and mRNA expression profiles and functional networks of vascular tissue in lipopolysaccharide-induced sepsis.

Sepsis is the most common cause of death in intensive care units. This study investigated the circular RNA (circRNA) and mRNA expression profiles and functional networks of the aortic tissue in sepsis. We established a lipopolysaccharide (LPS)-induced rat sepsis model. High-throughput sequencing was performed on the aorta tissue to identify differentially expressed (DE) circRNAs and mRNAs, which were validated by real-time quantitative polymerase chain reaction (RT-qPCR). Bioinformatic analysis was carried out and coding and non-coding co-expression (CNC) and competing endogenous RNA (ceRNA) regulatory networks were constructed to investigate the mechanisms. In total, 373 up-regulated and 428 down-regulated circRNAs and 2063 up-regulated and 2903 down-regulated mRNAs were identified. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of mRNAs showed that the down-regulated genes were mainly enriched in the process of energy generation. CNC and ceRNA regulatory networks were constructed with seven DE circRNAs. The results of functional enrichment analysis of CNC target genes revealed the important role of circRNAs in inflammatory response. The ceRNA network also highlighted the significant enrichment in calcium signalling pathway. Significant alterations in circRNAs and mRNAs were observed in the aortic tissue of septic rats. In addition, CNC and ceRNA networks were established.

Genome-wide identification of altered RNA m6A profiles in vascular tissue of septic rats.

Sepsis is the leading cause of death in hospital intensive care units. In light of recent studies showing that variations in N6-methyladenosine (m6A) levels in different RNA transcripts influence inflammatory responses, we evaluated the m6A profiles of rat aortic mRNAs and lncRNAs after lipopolysaccharide (LPS)-induced sepsis. LC-MS-based mRNA modification analysis showed that global m6A levels were significantly decreased in aortic tissue of rats injected intraperitoneally with LPS. This finding was consistent with downregulated expression of METTL3 and WTAP, two members of the m6A writer complex, in LPS-exposed aortas. Microarray analysis of m6A methylation indicated that 40 transcripts (31 mRNAs and 9 lncRNAs) were hypermethylated, while 223 transcripts (156 mRNAs and 67 lncRNAs) were hypomethylated, in aortic tissue from LPS-treated rats. On GO and KEGG analyses, 'complement and coagulation cascades', 'transient receptor potential channels', and 'organic anion transmembrane transporter activity' were the major biological processes modulated by the differentially m6A methylated mRNAs. In turn, competing endogenous RNA network analysis suggested that decreased m6A levels in lncRNA-XR_343955 may affect the inflammatory response through the cell adhesion molecule pathway. Our data suggest that therapeutic modulation of the cellular m6A machinery may be useful to preserve vascular integrity and function during sepsis.