The domestic pig (Sus scrofa), an important species in animal production industry, is a right model for studying adipogenesis and fat deposition. In order to expand the repertoire of porcine miRNAs and further explore potential regulatory miRNAs which have influence on adipogenesis, high-throughput Solexa sequencing approach was adopted to identify miRNAs in backfat of Large White (lean type pig) and Meishan pigs (Chinese indigenous fatty pig). We identified 215 unique miRNAs comprising 75 known pre-miRNAs, of which 49 miRNA*s were first identified in our study, 73 miRNAs were overlapped in both libraries, and 140 were novelly predicted miRNAs, and 215 unique miRNAs were collectively corresponding to 235 independent genomic loci. Furthermore, we analyzed the sequence variations, seed edits and phylogenetic development of the miRNAs. 17 miRNAs were widely conserved from vertebrates to invertebrates, suggesting that these miRNAs may serve as potential evolutional biomarkers. 9 conserved miRNAs with significantly differential expressions were determined. The expression of miR-215, miR-135, miR-224 and miR-146b was higher in Large White pigs, opposite to the patterns shown by miR-1a, miR-133a, miR-122, miR-204 and miR-183. Almost all novel miRNAs could be considered pig-specific except ssc-miR-1343, miR-2320, miR-2326, miR-2411 and miR-2483 which had homologs in Bos taurus, among which ssc-miR-1343, miR-2320, miR-2411 and miR-2483 were validated in backfat tissue by stem-loop qPCR. Our results displayed a high level of concordance between the qPCR and Solexa sequencing method in 9 of 10 miRNAs comparisons except for miR-1a. Moreover, we found 2 miRNAs, miR-135 and miR-183, may exert impacts on porcine backfat development through WNT signaling pathway. In conclusion, our research develops porcine miRNAs and should be beneficial to study the adipogenesis and fat deposition of different pig breeds based on miRNAs.

BackgroundStrains of extraintestinal pathogenic Escherichia coli (ExPEC) can invade and colonize extraintestinal sites and cause a wide range of infections. Genomic analysis of ExPEC has mainly focused on isolates of human and avian origins, with porcine ExPEC isolates yet to be sequenced. To better understand the genomic attributes underlying the pathogenicity of porcine ExPEC, we isolated two E. coli strains PCN033 and PCN061 from pigs, assessed their in vivo virulence, and completed and compared their genomes.ResultsAnimal experiments demonstrated that strain PCN033, but not PCN061, was pathogenic in a pig model. The chromosome of PCN033 was 384 kb larger than that of PCN061. Among the PCN033-specific sequences, genes encoding adhesins, unique lipopolysaccharide, unique capsular polysaccharide, iron acquisition and transport systems, and metabolism were identified. Additionally, a large plasmid PCN033p3 harboring many typical ExPEC virulence factors was identified in PCN033. Based on the genetic variation between PCN033 and PCN061, corresponding phenotypic differences in flagellum-dependent swarming motility and metabolism were verified. Furthermore, the comparative genomic analyses showed that the PCN033 genome shared many similarities with genomic sequences of human ExPEC strains. Additionally, comparison of PCN033 genome with other nine characteristic E. coli genomes revealed 425 PCN033-special coding sequences. Genes of this subset included those encoding type I restriction-modification (R-M) system, type VI secretion system (T6SS) and membrane-associated proteins.ConclusionsThe genetic and phenotypic differences between PCN033 and PCN061 could partially explain their differences in virulence, and also provide insight towards the molecular mechanisms of porcine ExPEC infections. Additionally, the similarities between the genomes of PCN033 and human ExPEC strains suggest that some connections between porcine and human ExPEC strains exist. The first completed genomic sequence for porcine ExPEC and the genomic differences identified by comparative analyses provide a baseline understanding of porcine ExPEC genetics and lay the foundation for their further study.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-1890-9) contains supplementary material, which is available to authorized users.

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Acetaminophen (APAP) overdose is the most frequent cause of drug-induced acute liver failure. The purpose of this study was to investigate whether paeonol protected against APAP-induced hepatotoxicity. Mice treated with paeonol (25, 50, 100 mg/kg) received 400 mg/kg acetaminophen intraperitoneally (i.p.) and hepatotoxicity was assessed. Pre-treatment with paeonol for 6 and 24 h ameliorated APAP-induced hepatic necrosis and significantly reduced the serum alanine aminotransferase (ALT) and aspartate transaminase (AST) levels in a dose-dependent manner. Post-treatment with 100 mg/kg paeonol ameliorated APAP-induced hepatic necrosis and reduced AST and ALT levels in the serum after APAP administration for 24 h. Western blot revealed that paeonol inhibited APAP-induced phosphorylated JNK protein expression but not p38 and Erk1/2. Moreover, paeonol showed anti-oxidant activities with reducing hepatic MDA contents and increasing hepatic SOD, GSH-PX and GSH levels. Paeonol dose-dependently prevented against H2O2 or APAP-induced LDH releasing and ROS production in primary mouse hepatocytes. In addition, the mRNA levels of pro-inflammatory genes such as TNF-α, MCP-1, IL-1β and IL-6 in the liver were dose-dependently reduced by paeonol pre-treatment. Pre-treatment with paeonol significantly inhibited IKKα/β, IκBα and p65 phosphorylation which contributed to ameliorating APAP-induced hepatic inflammation. Collectively, the present study demonstrates paeonol has a protective ability against APAP-induced hepatotoxicity and might be an effective candidate compound against drug-induced acute liver failure.

Background As one of the most common chronic diseases in the world, osteoporosis occurs especially in postmenopausal women. Circular RNAs (circRNAs) are emerging as major drivers in human disease. The aim of the present study was to analyse circRNA expression profiles in osteoporosis and to explore the clinical significance and the regulatory molecular mechanism of hsa_circ_0006859 during osteoporosis. Methods Exosomes were isolated from clinically collected serum samples. A circRNA microarray was performed to screen differentially expressed circRNAs. Quantitative real-time PCR (qRT-PCR) and western blot were performed to analyse target gene mRNA expression and protein expression. Alizarin red staining (ARS) was performed to evaluate the mineralization ability of human bone marrow mesenchymal stem cells (hBMSCs). Oil Red O staining was performed to evaluate the lipid droplet formation ability of hBMSCs. Bioinformatics analysis and the luciferase reporter assay were performed to investigate the interaction between two genes. Results Hsa_circ_0006859 was identified as one of the most upregulated circRNAs in the microarray analysis. Hsa_circ_0006859 in exosomes was upregulated in osteoporosis patients compared to healthy controls. Hsa_circ_0006859 differentiated osteopenia or osteoporosis patients from healthy controls with high sensitivity and specificity. Hsa_circ_0006859 suppressed osteoblastic differentiation and promoted adipogenic differentiation of hBMSCs. Hsa_circ_0006859 directly bound to miR-431-5p, and ROCK1 was identified as a novel target gene of miR-431-5p. Hsa_circ_0006859 is a competing endogenous RNA (ceRNA) of miR-431-5p that promotes ROCK1 expression. Hsa_circ_0006859 suppressed osteogenesis and promoted adipogenesis by sponging miR-431-5p to upregulate ROCK1. Conclusions Exosomal hsa_circ_0006859 is a potential biomarker for postmenopausal osteoporosis and controls the balance between osteogenesis and adipogenesis in hBMSCs by sponging miR-431-5p.