Identification of short hairpin RNA targeting foot-and-mouth disease virus with transgenic bovine fetal epithelium cells

Cows as Bioreactors for the Production of Nutritionally and Biomedically Significant Proteins

Dairy and beef cattle make a vital contribution to global nutrition, and since their domestication, they have been continuously exposed to natural and artificial selection to improve production characteristics. The technologies of transgenesis and gene editing used in cattle are responsible for generating news characteristics in bovine breeding, such as alteration of nutritional components of milk and meat enhancing human health benefits, disease resistance decreasing production costs and offering safe products for human food, as well as the recombinant protein production of biomedical significance. Different methodologies have been used to generate transgenic cattle as bioreactors. These methods include the microinjection of vectors in pronuclear, oocyte or zygote, sperm-mediate transgenesis, and somatic cell nuclear transfer. Gene editing has been applied to eliminate unwanted genes related to human and animal health, such as allergy, infection, or disease, and to insert transgenes into specific sites in the host genome. Methodologies for the generation of genetically modified cattle are laborious and not very efficient. However, in the last 30 years, transgenic animals were produced using many biotechnological tools. The result of these modifications includes (1) the change of nutritional components, including proteins, amino acids and lipids for human nutrition; (2) the removal allergic proteins milk; (3) the production of cows resistant to disease; or (4) the production of essential proteins used in biomedicine (biomedical proteins) in milk and blood plasma. The genetic modification of cattle is a powerful tool for biotechnology. It allows for the generation of new or modified products and functionality that are not currently available in this species.

Genome Editing Strategies to Protect Livestock from Viral Infections

The livestock industry is constantly threatened by viral disease outbreaks, including infections with zoonotic potential. While preventive vaccination is frequently applied, disease control and eradication also depend on strict biosecurity measures. Clustered regularly interspaced palindromic repeats (CRISPR) and associated proteins (Cas) have been repurposed as genome editors to induce targeted double-strand breaks at almost any location in the genome. Thus, CRISPR/Cas genome editors can also be utilized to generate disease-resistant or resilient livestock, develop vaccines, and further understand virus-host interactions. Genes of interest in animals and viruses can be targeted to understand their functions during infection. Furthermore, transgenic animals expressing CRISPR/Cas can be generated to target the viral genome upon infection. Genetically modified livestock can thereby reduce disease outbreaks and decrease zoonotic threats.

Glycogen Metabolism and Rheumatoid Arthritis: The Role of Glycogen Synthase 1 in Regulation of Synovial Inflammation via Blocking AMP-Activated Protein Kinase Activation

Objective

To investigate the role of glycogen metabolism in regulating rheumatoid fibroblast-like synoviocyte (FLS)-mediated synovial inflammation and its underlying mechanism.

Methods

FLSs were separated from synovial tissues (STs) obtained from rheumatoid arthritis (RA) patients. Glycogen content was determined by periodic acid Schiff staining. Protein expression was analyzed by Western blot or immunohistochemistry. Gene expression of cytokines and matrix metalloproteinases (MMPs) was evaluated by quantitative real-time PCR. FLS proliferation was detected by EdU incorporation. Migration and invasion were measured by Boyden chamber assay.

Results

Glycogen levels and glycogen synthase 1 (GYS1) expression were significantly increased in the ST and FLSs of RA patients. TNF-α or hypoxia induced GYS1 expression and glycogen synthesis in RA FLSs. GYS1 knockdown by shRNA decreased the expression of IL-1β, IL-6, CCL-2, MMP-1, and MMP-9 and proliferation and migration by increasing AMP-activated protein kinase (AMPK) activity in RA FLS. AMPK inhibitor or knockdown AMPK could reverse the inhibitory effect of GYS1 knockdown on the inflammatory response in RA FLSs; however, an AMPK agonist blocked RA FLS activity. We further determined that hypoxia-inducible factor-1α mediates TNF-α- or hypoxia-induced GYS1 expression and glycogen levels. Local joint depletion of GYS1 or intraperitoneal administration with an AMPK agonist ameliorated the severity of arthritis in rats with collagen-induced arthritis.

Conclusion

Our data demonstrate that GYS1-mediated glycogen accumulation contributes to FLS-mediated synovial inflammation in RA by blocking AMPK activation. In our knowledge, this is a first study linking glycogen metabolism to chronic inflammation. Inhibition of GYS1 might be a novel therapeutic strategy for chronic inflammatory arthritis, including RA.

RNAi combining Sleeping Beauty transposon system inhibits ex vivo expression of foot-and-mouth disease virus VP1 in transgenic sheep cells

Foot and mouth disease, which is induced by the foot and mouth disease virus (FMDV), takes its toll on the cloven-hoofed domestic animals. The VP1 gene in FMDV genome encodes the viral capsid, a vital element for FMDV replication. Sleeping Beauty (SB) is an active DNA-transposon system responsible for genetic transformation and insertional mutagenesis in vertebrates. In this study, a conserved VP1-shRNA which specifically targets the ovine FMDV-VP1 gene was constructed and combined with SB transposase and transposon. Then, they were microinjected into pronuclear embryos to breed transgenic sheep. Ninety-two lambs were born and the VP1-shRNA was positively integrated into eight of them. The rate of transgenic sheep production in SB transposon system was significantly higher than that in controls (13.04% vs. 3.57% and 7.14%, P < 0.05). The ear fibroblasts of the transgenic lambs transfected with the PsiCheck2-VP1 vector had a significant inhibitory effect on the VP1 gene of the FMDV. In conclusion, the VP1-shRNA transgenic sheep were successfully generated by the current new method. The ear fibroblasts from these transgenic sheep possess a great resistance to FMDV. The result indicated that RNAi technology combining the "Sleeping Beauty" transposon system is an efficient method to produce transgenic animals.

Host microRNA-203a Is antagonistic to the progression of foot-and-mouth disease virus infection

Sam68 was previously shown to be a critical host factor for foot-and-mouth disease virus (FMDV) replication. MicroRNA (miR) miR-203a is reportedly a negative regulator of Sam68 expression both in vitro and in vivo. Here, transfection of miR-203a-3p and miR-203a-5p mimics separately and in combination in a porcine cell line followed by FMDV infection resulted in diminished viral protein synthesis and a 4 and 6log reduction in virus titers relative to negative controls, respectively. Unexpectedly, Sam68 expression was increased by miR-203a-5p transfection, but not miR-203a-3p. miR-203a-5p also down-regulated Survivin expression, which was predicted to play a role in FMDV infection. Moreover, miR-203a-5p but not miR-203a-3p affected a reduction in FMDV viral RNA. These effects were not replicated with a related Picornavirus, suggesting FMDV specificity. Importantly, miR-203a-3p and miR-203a-5p impaired FMDV infection across multiple FMDV serotypes. We concluded that miR-203a-3p and miR-203a-5p represent attractive potential naturally occurring bio-therapeutics against FMDV.

The suppression of bromodomain and extra-terminal domain inhibits vascular inflammation by blocking NF-κB and MAPK activation

BACKGROUND AND PURPOSE

There is increasing evidence indicating that bromodomain and extra-terminal domain (BET) proteins play a critical role in the regulation of immune and inflammatory responses; however, their contribution to vascular inflammation has not yet been elucidated. In this study, we investigated the effect of inhibiting BET bromodomain on vascular inflammation and the underlying mechanisms.

EXPERIMENTAL APPROACH

HUVECs were isolated from fresh umbilical cords. JQ1, a specific BET bromodomain inhibitor, and Brd shRNA were used to evaluate the regulation of the BET proteins in vascular inflammation. Leukocyte adhesion to HUVECs was measure by an adhesion assay. Western blot or immunohistochemical analysis was used to detect the protein expression. Real-time PCR was used to evaluate mRNA expression. Leukocyte accumulation in vivo was determined by an acute lung inflammation model.

KEY RESULTS

BET bromodomain inhibition suppressed the expression of adhesion molecules induced by TNF-α- or LPS, including ICAM-1, VCAM-1 and E-selectin, and inhibited leukocyte adhesion to activated HUVEC monolayers. Treatment with JQ1 also attenuated the LPS-induced accumulation of leukocytes and expression of endothelial adhesion molecules in the acute lung inflammation model in vivo. Furthermore, BET bromodomain inhibition reduced the activity of p38 and JNK MAPKs and NF-κB in TNF-α-stimulated HUVECs. TNF-α-induced NF-κB activation was also blocked by inhibitors of p38 (SB203580) or JNK (SP600125).

CONCLUSIONS AND IMPLICATIONS

BET bromodomain is important for regulating endothelial inflammation. Strategies targeting endothelial BET bromodomain may provide a new therapeutic approach for controlling inflammatory-related diseases.

Small Non-coding RNAs Associated with Viral Infectious Diseases of Veterinary Importance: Potential Clinical Applications

MicroRNAs (miRNAs) represent a class of small non-coding RNA (sncRNA) molecules that can regulate mRNAs by inducing their degradation or by blocking translation. Considering that miRNAs are ubiquitous, stable, and conserved across animal species, it seems feasible to exploit them for clinical applications. Unlike in human viral diseases, where some miRNA-based molecules have progressed to clinical application, in veterinary medicine, this concept is just starting to come into view. Clinically, miRNAs could represent powerful diagnostic tools to pinpoint animal viral diseases and/or prognostic tools to follow up disease progression or remission. Additionally, the possible consequences of miRNA dysregulation make them potential therapeutic targets and open the possibilities to use them as tools to generate viral disease-resistant livestock. This review presents an update of preclinical studies on using sncRNAs to combat viral diseases that affect pet and farm animals. Moreover, we discuss the possibilities and challenges of bringing these bench-based discoveries to the veterinary clinic.

Tongue Epithelium Cells from shRNA Mediated Transgenic Goat Show High Resistance to Foot and Mouth Disease Virus

Foot and mouth disease induced by foot and mouth disease virus (FMDV) is severe threat to cloven-hoofed domestic animals. The gene 3Dpol in FMDV genome encodes the viral RNA polymerase, a vital element for FMDV replication. In this study, a conserved 3D-7414shRNA targeting FMDV-3Dpol gene was designed and injected into pronuclear embryos to produce the transgenic goats. Sixty-one goats were produced, of which, seven goats positively integrated 3D-7414shRNA. Loss of function assay demonstrated that siRNA effectively knockdown 3Dpol gene in skin epithelium cells of transgenic goats. Subsequently, the tongue epithelium cells from transgenic and non-transgenic goats were infected with FMDV O/YS/CHA/05 strain. A significant decrease of virus titres and virus copy number was observed in cells of transgenic goats compared with that of non-transgenic goats, which indicated that 3D-7414siRNA inhibited FMDV replication by interfering FMDV-3Dpol gene. Furthermore, we found that expression of TLR7, RIG-I and TRAF6 was lower in FMDV infected cells from transgenic goats compared to that from non-transgenic goats, which might result from lower virus copy number in transgenic goats’ cells. In conclusion, we successfully produced transgenic goats highly expressing 3D-7414siRNA targeting 3Dpol gene, and the tongue epithelium cells from the transgenic goats showed effective resistance to FMDV.

Protein Inhibitor of Activated STAT3 Regulates Migration, Invasion, and Activation of Fibroblast-like Synoviocytes in Rheumatoid Arthritis

The aggressive phenotype displayed by fibroblast-like synoviocytes (FLSs) is a critical factor of cartilage destruction in rheumatoid arthritis (RA). Increased FLSs migration and subsequent degradation of the extracellular matrix are essential to the pathology of RA. Protein inhibitor of activated STAT (PIAS), whose family members include PIAS1, PIAS2 (PIASx), PIAS3, and PIAS4 (PIASy), play important roles in regulating various cellular events, such as cell survival, migration, and signal transduction in many cell types. However, whether PIAS proteins have a role in the pathogenesis of RA is unclear. In this study, we evaluated the role of PIAS proteins in FLSs migration, invasion, and matrix metalloproteinases (MMPs) expression in RA. We observed increased expression of PIAS3, but not PIAS1, PIAS2, or PIAS4, in FLSs and synovial tissues from patients with RA. We found that PIAS3 knockdown by short hairpin RNA reduced migration, invasion, and MMP-3, MMP-9, and MMP-13 expression in FLSs. In addition, we demonstrated that PIAS3 regulated lamellipodium formation during cell migration. To gain insight into molecular mechanisms, we evaluated the effect of PIAS3 knockdown on Rac1/PAK1 and JNK activation. Our results indicated that PIAS3-mediated SUMOylation of Rac1 controlled its activation and modulated the Rac1 downstream activity of PAK1 and JNK. Furthermore, inhibition of Rac1, PAK1, or JNK decreased migration and invasion of RA FLSs. Thus, our observations suggest that PIAS3 suppression may be protective against joint destruction in RA by regulating synoviocyte migration, invasion, and activation.

Artificial microRNAs as antiviral strategy to FMDV: structural implications of target selection

RNA interference (RNAi) appears as a promising strategy to control virus replication. While the antiviral power of short-hairpin RNAs or small-interfering RNAs against FMDV has been demonstrated widely, safer RNAi effectors such as artificial microRNAs (amiRs) have not been evaluated extensively. In this work, transgenic monoclonal cell lines constitutively expressing different amiRs targeting FMDV 3D-coding region or 3'UTR were established. Certain cell lines showed an effective, sequence-specific amiR-mediated silencing activity that was accomplished by degradation of the target mRNA, as demonstrated in co-transfection experiments of reporter genes fused to FMDV target sequences. However, FMDV replication in these amiR-expressing cells was affected barely. Experiments aimed at elucidating the cause of RNAi failure demonstrated limited accessibility of the targeted region in the molecular environment of the viral RNA. Since RNAi is mediated by large-dimension silencing complexes containing the siRNA and not simply by a linear oligonucleotide, we propose that target selection should consider not only the local RNA structure but also the global conformation of target RNA.

Development and characterization of a recombinant infectious bronchitis virus expressing the ectodomain region of S1 gene of H120 strain

Infectious bronchitis (IB), caused by infectious bronchitis virus (IBV), is a highly contagious chicken disease, and can lead to serious economic losses in poultry enterprises. The continual introduction of new IBV serotypes requires alternative strategies for the production of timely and safe vaccines against the emergence of variants. Modification of the IBV genome using reverse genetics is one way to generate recombinant IBVs as the candidates of new IBV vaccines. In this study, the recombinant IBV is developed by replacing the ectodomain region of the S1 gene of the IBV Beaudette strain with the corresponding fragment from H120 strain, designated as rBeau-H120(S1e). In Vero cells, the virus proliferates as its parental virus and can cause syncytium formation. The peak titer would reach 10(5.9) 50% (median) tissue culture infective dose/mL at 24 h post-infection. After inoculation of chickens with the recombinant virus, it demonstrated that rBeau-H120(S1e) remained nonpathogenic and was restricted in its replication in vivo. Protection studies showed that vaccination with rBeau-H120 (S1e) at 7-day after hatch provided 80% rate of immune protection against challenge with 10(3) 50% embryos infection dose of the virulent IBV M41 strain. These results indicate that rBeau-H120 (S1e) has the potential to be an alternative vaccine against IBV based on excellent propagation property and immunogenicity. This finding might help in providing further information that replacement of the ectodomain fragment of the IBV Beaudette S1 gene with that from a present field strain is promising for IBV vaccine development.

Transgenically mediated shRNAs targeting conserved regions of foot-and-mouth disease virus provide heritable resistance in porcine cell lines and suckling mice

Foot-and-mouth disease virus (FMDV) is responsible for substantial economic losses in livestock breeding each year, and the development of new strategies is needed to overcome the limitations of existing vaccines and antiviral drugs. In this study, we evaluated the antiviral potential of transgenic porcine cells and suckling mice that simultaneously expressed two short-hairpin RNAs (shRNAs) targeting the conserved regions of the viral polymerase protein 3D and the non-structural protein 2B. First, two recombinant shRNA-expressing plasmids, PB-EN3D2B and PB-N3D2B, were constructed and the efficiency of the constructs for suppressing an artificial target was demonstrated in BHK-21 cells. We then integrated PB-EN3D2B into the genome of the porcine cell line IBRS-2 using the piggyBac transposon system, and stable monoclonal transgenic cell lines (MTCL) were selected. Of the 6 MTCL that were used in the antiviral assay, 3 exhibited significant resistance with suppressing ratios of more than 94% at 48 hours post-challenge (hpc) to both serotype O and serotype Asia 1 FMDV. MTCL IB-3D2B-6 displayed the strongest antiviral activity, which resulted in 100% inhibition of FMDV replication until 72 hpc. Moreover, the shRNA-expressing fragment of PB-N3D2B was integrated into the mouse genome by DNA microinjection to produce transgenic mice. When challenged with serotype O FMDV, the offspring of the transgenic mouse lines N3D2B-18 and N3D2B-81 exhibited higher survival rates of 19% to 27% relative to their non-transgenic littermates. The results suggest that these heritable shRNAs were able to suppress FMDV replication in the transgenic cell lines and suckling mice.

Production of cloned pigs with targeted attenuation of gene expression

The objective of this study was to demonstrate that RNA interference (RNAi) and somatic cell nuclear transfer (SCNT) technologies can be used to attenuate the expression of specific genes in tissues of swine, a large animal species. Apolipoprotein E (apoE), a secreted glycoprotein known for its major role in lipid and lipoprotein metabolism and transport, was selected as the target gene for this study. Three synthetic small interfering RNAs (siRNA) targeting the porcine apoE mRNA were tested in porcine granulosa cells in primary culture and reduced apoE mRNA abundance ranging from 45-82% compared to control cells. The most effective sequence was selected for cloning into a short hairpin RNA (shRNA) expression vector under the control of RNA polymerase III (U6) promoter. Stably transfected fetal porcine fibroblast cells were generated and used to produce embryos with in vitro matured porcine oocytes, which were then transferred into the uterus of surrogate gilts. Seven live and one stillborn piglet were born from three gilts that became pregnant. Integration of the shRNA expression vector into the genome of clone piglets was confirmed by PCR and expression of the GFP transgene linked to the expression vector. Analysis showed that apoE protein levels in the liver and plasma of the clone pigs bearing the shRNA expression vector targeting the apoE mRNA was significantly reduced compared to control pigs cloned from non-transfected fibroblasts of the same cell line. These results demonstrate the feasibility of applying RNAi and SCNT technologies for introducing stable genetic modifications in somatic cells for eventual attenuation of gene expression in vivo in large animal species.

Bovine fetal epithelium cells expressing shRNA targeting viral VP1 gene resisted against foot-and-mouth disease virus

RNAi could protect experimental animals from Foot-and-mouth disease virus (FMDV), but pivotal issue is delivery of RNAi. In this study, shRNA recombinant lentiviral plasmid RNAi-LT6 targeting VP1 of FMDV, which strongly suppressed the transient expression of a FLAG-tagged VP1 protein in 293T cells and significantly inhibited viral replication in BHK-21 cells, was screened and transfected into bovine fetal fibroblast cells. With subsequent somatic cell cloning, three 4-month-old transgenic fetuses were obtained, and integration into chromosome and expression of shRNA in primary transgenic tongue epithelium cells were confirmed by Southern hybridization and Northern assay, respectively. shRNA significantly suppressed viral RNA synthesis and viral replication in primary transgenic tongue epithelium cells after inoculation of 200 TCID50 of FMDV. The results suggested that transgenic cloning may be a useful tool for RNAi delivery and RNAi anti-viral strategy, and RNAi-LT6 could be a candidate shRNA used for preparation of transgenic cattle against FMDV.