miRNAs associated with immune response in teleost fish

Abstract

MicroRNAs (miRNAs) have been identified as important post transcriptional regulators of gene expression. In higher vertebrates, a subset of miRNAs has been identified as important regulators of a number of key genes in immune system gene networks, and this paper review recent studies on miRNAs associated with immune response in teleost fish. Challenge studies conducted in several species have identified differently expressed miRNAs associated with viral or bacterial infection. The results from these studies point out several miRNAs that are likely to have evolutionary conserved functions that are related to immune response in teleost fish. Changed expression levels of mature miRNAs from the five miRNA genes miRNA-462, miRNA-731, miRNA-146, miRNA-181 and miRNA-223 are observed following viral as well as bacterial infection in several teleost fish. Furthermore, significant changes in expression of mature miRNAs from the five genes miRNA-21, miRNA-155, miRNA-1388, miRNA-99 and miRNA-100 are observed in multiple studies of virus infected fish while changes in expression of mature miRNA from the three genes miRNA-122, miRNA-192 and miRNA-451 are observed in several studies of fish with bacterial infections. Interestingly, some of these genes are not present in higher vertebrates. The function of the evolutionary conserved miRNAs responding to infection depends on the target gene(s) they regulate. A few target genes have been identified while a large number of target genes have been predicted by in silico analysis. The results suggest that many of the targets are genes from the host's immune response gene networks. We propose a model with expected temporal changes in miRNA expression if they target immune response activators/effector genes or immune response inhibitors, respectively. The best way to understand the function of a miRNA is to identify its target gene(s), but as the amount of genome resources for teleost fish is limited, with less well characterized genomes and transcriptomes, identifying the true target genes of the miRNAs associated with the immune response is a challenge. Identifying such target genes by applying new methods and approaches will likely be the next important step to understand the function of the miRNAs associated with immune response in teleost fish.

Dietary Immunostimulant CpG Modulates MicroRNA Biomarkers Associated with Immune Responses in Atlantic Salmon (Salmo salar)

“…Although there have been no studies to date reporting the association of miR-30e with antiviral immune response in Atlantic salmon, a previous study in Atlantic salmon infected with the intracellular bacterium P. salmonis did show increased miR-30e expression in both spleen and head kidney [23]. miR-181 and miR-462 were classified as evolutionarily conserved miRNAs associated with immune response in teleosts following viral challenges [18]. The expression of miR-181a was increased in response to red-spotted grouper nervous necrosis virus in a head kidney cell line of half-smooth tongue sole [49].…”

“…Analyses of Atlantic salmon tissues infected with P. salmonis revealed 84 and 25 differentially expressed miRNAs in head kidney and spleen, respectively; functional annotation of predicted mRNA targets of P. salmonis-responsive miRNAs showed involvement in the immune response, such as genes related to chemokine-mediated signaling pathway and neutrophil chemotaxis [23]. Such studies have improved our understanding of miRNAs involved in immune responses in teleosts [18]. However, the impact of pIC-triggered antiviral and ASAL-triggered antibacterial immune responses on the miRNA expression in Atlantic salmon were previously uncharacterized.…”

“…Immune response-mediated gene expression can be regulated through small non-coding RNAs (ncRNAs) including microRNAs (miRNAs) [18][19][20][21]. miRNAs are important regulators of gene expression at the post-transcriptional level [18,22]. The primary miRNA transcripts (pri-miRNAs) are cleaved by Drosha into shorter miRNA precursors (pre-miRNAs).…”

Transcriptom analysis revealed regulation of dexamethasone induced microRNAs in chicken thymus

“…3 Previous research showed that miR-365 functions were a more powerful regulator of interleukin-6 (IL-6) than let-7a in vitro. 5 Further study on the role of miRNAs in chicken immune organ formation confirmed that miRNAs were associated with bursal and lymphocyte developmental differentiation. 5 Further study on the role of miRNAs in chicken immune organ formation confirmed that miRNAs were associated with bursal and lymphocyte developmental differentiation.…”

A MiRNA-based Signature is Associated With Tumor Mutational Burden in Colon Adenocarcinoma

“…MicroRNAs (miRNAs) plays an important role in the post-transcriptional regulation of the translation of mutant genes into modi ed proteins.MiRNAsare classes of non-coding single-stranded RNA molecules encoded by endogenous genes with a length of about 22 nucleotides, they are involved in the regulation of post-transcriptional gene expression in animals and plants.The abnormal expression of miRNAs is often associated with many diseases, especially cancer [9,10].With the rise of miRNAs research in recent years, we realize that miRNA plays an irreplaceable role in cancer.Several studies have shown that miRNAs may be a prognostic marker for various cancers [10].MiRNAs plays an important role in tumor microenvironment [11][12][13][14]. Studies have shown that the expression of miRNAs in some tumors is highly speci c, and it plays a very important role in immune response, especially in early regulation.In the process of tumor development, the immune system plays a key role, and there is a close interaction between tumor cells and immune cells by releasing a variety of signals [15,16]. It has been shown that miRNAs can be used as a medium of communication between tumor cells and immune cells.…”