Identification of target genes and pathways associated with chicken microRNA miR-143
ANIMAL GENETICS
Authors: Trakooljul, N.; Hicks, J. A.; Liu, H. -C.
Abstract
P>MicroRNA (miRNA) is a family of small regulatory RNAs that post-transcriptionally regulate many biological functions including growth and development. Recently, the expression of chicken miRNA miR-143 was identified by using a deep sequencing approach. In other vertebrate species, miR-143 functions as a regulator of adipocyte differentiation and as a tumour suppressor. However, little is known about the biological function(s) of miR-143 in chickens. To study the functions of chicken miR-143, DNA microarray analysis and a dual luciferase reporter assay were employed to identify genes directly targeted by miR-143 as well as other biologically relevant genes. Microarray analysis indicated that 124 genes were differentially expressed upon in vitro anti-miR-143 treatment in embryonic chick splenocytes (P-value cutoff < 0.01). Many of these genes are associated with cell proliferation, apoptosis and tumourigenesis. Six of the up-regulated genes possess at least one potential miR-143 binding site in their 3'UTRs, of these the binding sites of PYCR2, PSTPIP1 and PDCD5 were validated by an in vitro luciferase reporter assay. In addition, several potential targets with important biological functions were identified by the miRanda algorithm and experimentally confirmed. These targets include KLF5, MAP3K7, TARDBP and UBE2E3, which have conserved miR-143 binding sites across multiple vertebrate species. Potential chicken specific miR-143 target sites were also validated for LPIN1, PCK2, PYCR2, METTL14, SLC2A2 and TNFSF10. Overall, the current study suggests that miR-143 is ubiquitously expressed among tissues and is likely to be involved in the regulation of cell proliferation and apoptosis.
Transcription profiling of peripheral B cells in antibody-positive primary Sjogren's syndrome reveals upregulated expression of CX3CR1 and a type I and type II interferon signature
SCANDINAVIAN JOURNAL OF IMMUNOLOGY
Authors: Imgenberg-Kreuz, J.; Sandling, J. K.; Bjork, A.; Nordlund, J.; Kvarnstrom, M.; Eloranta, M. -L.; Ronnblom, L.; Wahren-Herlenius, M.; Syvanen, A. -C.; Nordmark, G.
Abstract
B cells play a key role in the pathogenesis of primary Sjogren's syndrome (pSS). The aim of this study was to analyse the transcriptome of CD19+ B cells from patients with pSS and healthy controls to decipher the B cell-specific contribution to pSS. RNA from purified CD19+ B cells from 12 anti-SSA antibody-positive untreated female patients with pSS and 20 healthy blood donors was subjected to whole transcriptome sequencing. A false discovery rate corrected significance threshold of <0.05 was applied to define differential gene expression. As validation, gene expression in B cells from 17 patients with pSS and 16 healthy controls was analysed using a targeted gene panel. RNA-sequencing identified 4047 differentially expressed autosomal genes in pSS B cells. Upregulated expression of type I and type II interferon (IFN)-induced genes was observed, establishing an IFN signature in pSS B cells. Among the top upregulated and validated genes were CX3CR1, encoding the fractalkine receptor involved in regulation of B-cell malignancies, CCL5/RANTES and CCR1. Increased expression of several members of the TNF superfamily was also identified; TNFSF4/Ox40L, TNFSF10/TRAIL, TNFSF13B/BAFF, TNFRSF17/BCMA as well as S100A8 and -A9/calprotectin, TLR7, STAT1 and STAT2. Among genes with downregulated expression in pSS B cells were SOCS1 and SOCS3, CD70 and TNFAIP3/A20. We conclude that B cells from patients with anti-SSA antibody-positive pSS display immune activation with upregulated expression of chemokines, chemokine receptors and a prominent type I and type II IFN signature, while suppressors of cytokine signalling are downregulated. This adds insight into the autoimmune process and suggests potential targets for future functional studies.