Interplay of Cellular mRNA, miRNA and Viral miRNA during Infection of a Cell

LncRNA NR2F2-AS1 inhibits the progression of oral squamous cell carcinoma by mediating the miR-32-5p/SEMA3A axis

Previous studies have supported a tumor-suppressive role of semaphorin 3A (SEMA3A) in several tumors including oral squamous cell carcinoma (OSCC). However, in-depth characterization of the role of SEMA3A in OSCC and the underlying molecular mechanisms is lacking. Gene and protein expressions were detected using quantitative real-time PCR, western blot assay, and immunohistochemistry. OSCC cell metastasis was evaluated using Transwell and angiogenesis of human umbilical vein endothelial cells (HUVECs) was determined using tube formation assay. The interactions among molecules were predicted using bioinformatics analysis and validated using luciferase activity experiment and RNA immunoprecipitation assay. Pulmonary metastasis was evaluated using hematoxylin and eosin staining after constructing a lung metastasis tumor model in mice. SEMA3A expression was decreased in OSCC cells and its overexpression led to suppression of epithelial-mesenchymal transition (EMT), migration, and invasion of OSCC cells and angiogenesis of HUVECs. miR-32-5p was identified as an upstream molecule of SEMA3A and long non-coding RNA NR2F2 antisense RNA 1 (NR2F2-AS1) was validated as an upstream gene of miR-32-5p. Further experiments revealed that the inhibitory effects of NR2F2-AS1 overexpression on EMT, migration, invasion of OSCC cells, and angiogenesis of HUVECs as well as tumor growth and metastasis in mice were mediated via the miR-32-5p/SEMA3A axis. To conclude, NR2F2-AS1 may attenuate OSCC cell metastasis and angiogenesis of HUVECs and suppress tumor growth and metastasis in mice via the miR-32-5p/SEMA3A axis.

Host miRNA and mRNA profiles during in DEF and duck after DHAV-1 infection

DHAV-1 is a highly infectious pathogen that can cause acute hepatitis in ducklings. MicroRNA (miRNA) plays an essential regulatory role in virus response. We characterized and compared miRNA and mRNA expression profiles in duck embryonic fibroblasts (DEF) and the liver of ducklings infected with DHAV-1. DHAV-1 infected DEF was divided into infection group (D group) and blank group (M group), and DHAV-1 infected duckling group was divided into infection group (H group) and blank group (N group). D vs. M have 130 differentially expressed (DE) miRNA (DEM) and 2204 differentially expressed (DE) mRNA (DEG), H vs. N have 72 DEM and 1976 DEG. By the intersection of D vs. M and H vs. N comparisons, 15 upregulated DEM, 5 downregulated DEM, 340 upregulated DEG and 50 downregulated DEG were found with both in vivo and in vitro DHAV-1 infection. In particular, we identified the same DE miRNA target genes and functional annotations of DE mRNA. We enriched with multiple gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, which may have important roles in viral virulence, host immunity, and metabolism. We selected miR-155, which is co-upregulated, and found that miR-155 targets SOCS1 to inhibit DHVA-1 replication.

Identification and Characterization of Immune-Associated MicroRNAs in Silver Carp (Hypophthalmichthys molitrix) Responding to Aeromonas veronii and LPS Stimulation

The ubiquitous Gram-negative bacterial pathogen Aeromonas veronii (A. veronii) can easily cause inflammatory reactions in aquatic organisms, resulting in high mortality and huge economic losses. MicroRNAs (miRNAs) participate in immune regulation and have certain conserved properties. MiRNAs are involved in the immune responses of a variety of teleost fish infected with bacteria, whereas there is no related report in silver carp (Hypophthalmichthys molitrix). Therefore, we identified the expression profiles of miRNA in silver carp stimulated by A. veronii and LPS. Among them, the quantity of differentially expressed miRNAs (DEmiRNAs) obtained in the silver carp challenge group was 73 (A. veronii) and 90 (LPS). The GO enrichment and analysis of KEGG pathways have shown that the predicted target genes are mainly associated with lipid metabolism and the immune response in silver carp. This indicates the possibility that miRNAs play a role in regulating immune-related pathways. In addition, a total of eight DEmiRNAs validated the accuracy of the sequencing result via quantitative real-time PCR (qRT-PCR). Finally, we selected the silver carp head kidney macrophage cells (HKCs) as model cells and proved that miR-30b-5p can regulate the inflammatory response in silver carp HKCs. This study lays the foundation for exploring miRNA regulation in silver carp during pathogenic bacterial infection. In addition, it provides a reference for the future development of non-coding RNA antibacterial drugs.