Differential expression of porcine microRNAs in African swine fever virus infected pigs: a proof-of-concept study

Abstract

BackgroundAfrican swine fever (ASF) is a re-expanding devastating viral disease currently threatening the pig industry worldwide. MicroRNAs are a class of 17–25 nucleotide non- coding RNAs that have been shown to have critical functions in a wide variety of biological processes, such as cell differentiation, cell cycle regulation, carcinogenesis, apoptosis, regulation of immunity as well as in viral infections by cleavage or translational repression of mRNAs. Nevertheless, there is no information about miRNA expression in an ASFV infection.MethodsIn this proof-of-concept study, we have analyzed miRNAs expressed in spleen and submandibular lymph node of experimentally infected pigs with a virulent (E75) or its derived attenuated (E75CV1) ASFV strain, as well as, at different times post-infection with the virulent strain, by high throughput sequencing of small RNA libraries.ResultsSpleen presented a more differential expression pattern than lymph nodes in an ASFV infection. Of the most abundant miRNAs, 12 were differentially expressed in both tissues at two different times in infected animals with the virulent strain. Of these, miR-451, miR-145-5p, miR-181a and miR-122 presented up-regulation at late times post-infection while miR-92a, miR-23a, miR-92b-3p, miR-126-5p, miR-126-3p, miR-30d, miR-23b and miR-92c showed down-regulation. Of the 8 differentially expressed miRNAs identified at the same time post-infection in infected animals with the virulent strain compared with animals infected with its attenuated strain, miR-126-5p, miR-92c, miR-92a, miR-30e-5p and miR-500a-5p presented up-regulation whereas miR-125b, miR-451 and miR-125a were down-regulated. All these miRNAs have been shown to be associated with cellular genes involved in pathways related to the immune response, virus-host interactions as well as with several viral genes.ConclusionThe study of miRNA expression will contribute to a better understanding of African swine fever virus pathogenesis, essential in the development of any disease control strategy.Electronic supplementary materialThe online version of this article (10.1186/s12985-017-0864-8) contains supplementary material, which is available to authorized users.

MicroRNAs as Biomarkers for Animal Health and Welfare in Livestock

“…The effect of African swine fever virus (ASFV) infection on pig miRNAs has been investigated in vivo by comparing miRNA expression in animals infected with two viral strains (virulent vs. attenuated) (131). Ten miRNAs were selected for target prediction based on the highest representation by tissue and conditions, namely, miR-23a, miR-30e-5p, miR-92a, miR-122, miR-125b, miR-126-5p, miR-145-5p, miR-125a, miR-451, and miR-126-3p.…”

“…Ten miRNAs were selected for target prediction based on the highest representation by tissue and conditions, namely, miR-23a, miR-30e-5p, miR-92a, miR-122, miR-125b, miR-126-5p, miR-145-5p, miR-125a, miR-451, and miR-126-3p. The putative target genes were related to immune responses, such as B and T cell receptor signaling pathways, natural killer cell-mediated cytotoxicity, or Fc gamma R-mediated phagocytosis, as well as with processes related to infection-related pathogenesis and virus-host interaction (131). In another in vivo study, the same authors assessed the potential for ASFV to encode its own miRNAs, with negative results (132).…”

Host–virus interactions and defense mechanisms for giant viruses

“…Whereas infection with the attenuated E75CV1 strain was associated with an upregulation of genes encoding proteins involved in the activation of different innate immune pathways, infection with the virulent E75 strain was associated with the downregulation of the expression of genes encoding SERPINA3, induced during inflammation, or vitamin Dbinding protein involved in macrophage activation and inflammation. 152,153 In addition, the study by deep sequencing of microRNA gene expression in spleen and submandibular lymph nodes infected with virulent and attenuated ASFV strains revealed modifications in microRNAs (miRNAs) expression patterns. Indeed, miR-23a, miR-92a, miR-122, miR-125a, miR-125b, miR-126-5p, miR-30e-5p, miR-451, and miR-145-5p were either up or downregulated during infection with the virulent E75 viral strain.…”

Identification of a Functional Small Noncoding RNA of African Swine Fever Virus

“…The effect of ASFV infection on host miRNAs has been investigated in vivo by comparing miRNA expression in pigs infected with a virulent strain to those infected with an attenuated strain ( 30 ). These authors identified 12 miRNAs that were differentially expressed.…”