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

MicroRNA-21 from bone marrow mesenchymal stem cell-derived extracellular vesicles targets TET1 to suppress KLF4 and alleviate rheumatoid arthritis

Background

Accumulating evidence has demonstrated that bone marrow mesenchymal stem cells (BMSCs)-derived extracellular vesicles (EVs) can be used effectively to transfer drugs and biomolecules to target lesions. Meanwhile, BMSCs have been reported to be beneficial in the treatment of rheumatoid arthritis (RA). In this study, we employ gain- and loss-of-function experiments to determine how BMSCs-derived EVs alleviate RA in vitro and in vivo.

Methods

We isolated EVs from BMSCs and characterized them by transmission electron microscopy and western blot analysis. The regulatory relationship between miR-21 and TET1 was predicted by bioinformatics analysis and validated by dual luciferase assay. Next, we utilized bisulfite sequencing PCR to decipher how TET1 promoted KLF4 transcription. Then, we established an RA mouse model and determined the role of miR-21 in RA progression. Functional assays were used to validate the role the miR-21-TET1-KLF4 regulatory axis in controlling mouse fibroblast-like synoviocytes (mFLS) cell proliferation and inflammatory cytokines secretion in vitro.

Results

RT-qPCR results revealed that miR-21 was highly expressed in BMSCs-derived EVs, and confirmed that BMSCs-derived EVs transferred miR-21 into mFLS cells. Bioinformatic analysis predicted that TET1 was the directly downstream target of miR-21, which was further validated by dual luciferase assay. TET1 promoted KLF4 promoter methylation to increase its expression. Collectively, BMSCs-derived EVs relieved RA by delivering miR-21, while the exosomal miR-21 alleviated RA through targeting the TET1/KLF4 regulatory axis.

Conclusion

miR-21 from BMSCs-derived EVs suppresses KLF4 to relive RA by targeting TET1.

Bovine tongue epithelium-derived cells: A new source of bovine mesenchymal stem cells

Mesenchymal stem cells (MSCs) possess the ability to differentiate into multiple cell lineages, and thus, confer great potential for use in regenerative medicine and biotechnology. In the present study, we attempted to isolate and characterize bovine tongue tissue epithelium-derived MSCs (boT-MSCs) and investigate the culture conditions required for long-term culturing of boT-MSCs. boT-MSCs were successfully isolated by the collagenase digestion method and their proliferative capacity was maintained for up to 20 or more passages. We observed a significant increase in the proliferation of boT-MSCs during the 20 consecutive passages under low-glucose Dulbecco’s modified Eagle’s medium culture condition among the three culture conditions. These boT-MSCs presented pluripotency markers (octamer-binding transcription factor 3/4 (Oct3/4) and sex determining region Y-box2 (Sox2)) and cell surface markers, which included CD13, CD29, CD44, CD73, CD90, CD105, CD166, and major histocompatibility complex (MHC) class I (MHC-I) but not CD11b, CD14, CD31, CD34, CD45, CD80, CD86, CD106, CD117, and MHC-II at third passage. Moreover, these boT-MSCs could differentiate into mesodermal (adipocyte, osteocyte, and chondrocyte) cell lineages. Thus, the present study suggests that the tongue of bovines could be used as a source of bovine MSCs.

Sheep and Goat Genome Engineering: From Random Transgenesis to the CRISPR Era

Sheep and goats are valuable livestock species that have been raised for their production of meat, milk, fiber, and other by-products. Due to their suitable size, short gestation period, and abundant secretion of milk, sheep and goats have become important model animals in agricultural, pharmaceutical, and biomedical research. Genome engineering has been widely applied to sheep and goat research. Pronuclear injection and somatic cell nuclear transfer represent the two primary procedures for the generation of genetically modified sheep and goats. Further assisted tools have emerged to enhance the efficiency of genetic modification and to simplify the generation of genetically modified founders. These tools include sperm-mediated gene transfer, viral vectors, RNA interference, recombinases, transposons, and endonucleases. Of these tools, the four classes of site-specific endonucleases (meganucleases, ZFNs, TALENs, and CRISPRs) have attracted wide attention due to their DNA double-strand break-inducing role, which enable desired DNA modifications based on the stimulation of native cellular DNA repair mechanisms. Currently, CRISPR systems dominate the field of genome editing. Gene-edited sheep and goats, generated using these tools, provide valuable models for investigations on gene functions, improving animal breeding, producing pharmaceuticals in milk, improving animal disease resistance, recapitulating human diseases, and providing hosts for the growth of human organs. In addition, more promising derivative tools of CRISPR systems have emerged such as base editors which enable the induction of single-base alterations without any requirements for homology-directed repair or DNA donor. These precise editors are helpful for revealing desirable phenotypes and correcting genetic diseases controlled by single bases. This review highlights the advances of genome engineering in sheep and goats over the past four decades with particular emphasis on the application of CRISPR/Cas9 systems.

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.