Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most economically important viruses affecting the swine industry worldwide. MicroRNAs have recently been demonstrated to play vital roles in virus-host interactions. Our previous research on small RNA deep sequencing showed that the expression level of miR-10a increased during the viral life cycle. The present study sought to determine the function of miR-10a and its molecular mechanism during PRRSV infection. In the current study, the result of PRRSV infection inducing miR-10a expression was validated by quantitative reverse transcriptase PCR. Overexpression of miR-10a-5p using its mimics markedly reduced the expression level of intracellular PRRSV ORF7 mRNA and N protein. Simultaneously, overexpression of miR-10a-5p also significantly decreased the expression level of extracellular viral RNA and virus titres in the supernatants. These results demonstrated that miR-10a-5p could suppress the replication of PRRSV. A direct interaction between miR-10a-5p and signal recognition particle 14 (SRP14) was confirmed using bioinformatic prediction and experimental verification. miR-10a-5p could directly target the 3'UTR of pig SRP14 mRNA in a sequence-specific manner and decrease SRP14 expression through translational repression but not mRNA degradation. Further, knockdown of SRP14 by small interfering RNA also inhibits the replication of PRRSV. Collectively, these results suggested that miR-10a-5p inhibits PRRSV replication through suppression of SRP14 expression, which not only provides new insights into virus-host interactions during PRRSV infection but also suggests potential new antiviral strategies against PRRSV infection.

Reactive oxygen species (ROS) damage mammalian sperm during liquid storage. Notoginsenoside R1 (NR1) is a compound isolated from the roots of Panax notoginseng; it has powerful ROS‐scavenging activities. This work hypothesized that the antioxidant capacity of NR1 could improve boar sperm quality and fertility during liquid storage. During liquid storage at 17°C, the supplementation of semen extender with NR1 (50 μM) significantly improved sperm motility, membrane integrity and acrosome integrity after 5 days of preservation. NR1 treatment also reduced ROS and lipid peroxidation (LPO) levels at day 5 (p <0.05). Higher glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) levels and sperm–zona pellucida binding capacity were observed in the 50 μM NR1 group than those in the control group at day 7 (p <0.05). Importantly, statistical analysis of the fertility of 200 sows indicated that addition of NR1 to the extender improved the fertility parameters of boar spermatozoa during liquid storage at 17°C (p <0.05). These results demonstrate the practical feasibility of using 50 μM NR1 as an antioxidant in boar extender during liquid storage at 17°C, which is beneficial to both spermatozoa quality and fertility.

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Myostatin (MSTN) and somatostatin (SST) are negative regulate factors in the animals. Immunized animals with these proteins induce the related immune response, which could neutralize the normal inhibitory effects of these proteins. Since adenovirus was the mostly wildly used vector for delivering vaccine antigen, here, a recombinant adenovirus expressing MSTN-SST were constructed and mice were inoculated with the recombinant adenovirus. As our predicted, immunization with this adenovirus one time or two times were all induced the specific immune response and resulting in an improve growth rate and muscle mass. And boost immunization improved the effect of the immunization. Accordingly, adenovirus can be used as a vector for deliver myostatin and somatostatin gene, so as to increase animal growth rate and muscle mass of the animals.

It has been demonstrated that the activator protein related transcription factor Finkel-Biskis-Jinkins murine osteosarcoma B (GosB) is involved in preadipocyte differentiation and triacylglycerol synthesis. However, the role of GosB in regulating the synthesis of milk fatty acid in mouse mammary glands remains unclear. This research uncovered potentially new roles of GosB in suppressing milk fatty acid synthesis. Results revealed that GosB had the highest expression in lung tissue and showed a higher expression level during nonlactation than during lactation. GosB inhibited the expression of fatty acid synthase (FASN), stearoyl-CoA desaturase (SCD), fatty acid binding protein 4 (FABP4), diacylglycerol acyltransferase 1 (DGAT1), perilipin 2 (PLIN2), perilipin 3 (PLIN3), and C/EBPα in mouse mammary gland epithelial cells (MEC). In addition, GosB reduced cellular triglyceride content and the accumulation of lipid droplets; in particular, GosB enhanced saturated fatty acid concentration (C16:0 and C18:0). The PPARγ agonist, rosiglitazone (ROSI), promoted apoptosis and inhibited cell proliferation. GosB increased the expression of Bcl-2 and protected MEC from ROSI-induced apoptosis. Furthermore, MECs were protected from apoptosis through the GosB regulation of intracellular calcium concentrations. These findings suggest that GosB may regulate mammary epithelial cells milk fat synthesis and apoptosis via PPARγ in mouse mammary glands.

BackgroundMyostatin (MSTN), a type of transforming growth factor, can negatively regulate skeletal muscle growth. Immunisation of mice with recombinant yeast expressing MSTN increased bodyweight and muscle composition of them. Somatostatin (SST) is an inhibitory effector of growth hormone (GH), and active immunisation against SST with a DNA vaccine improves the growth performance of piglets via an influence on GH secretion. Here, a recombinant adenovirus was constructed and used to deliver MSTN-SST to mice to achieve the goal of regulation the growth performance of the mice. ResultsA recombinant adenovirus, rAd-MSTN-SST, expressing the MSTN-SST fusing protein was successfully rescued in HEK293A cells. The expressions of MSTN-SST were confirmed by western blotting and indirect immunofluorescence. Mice immunised with rAd-MSTN-SST were successfully induced to have an immune response against MSTN-SST, which increased their growth rate and muscle mass. In addition, a booster immunisation was beneficial in terms of higher antibody response and mouse growth rate. ConclusionsFusing protein MSTN-SST is a good candidate for regulating animal growth rate and muscle mass. Adenovirus can be used as a vector for delivering MSTN and SST to animals.