Establishment and evaluation of a PRRSV-sensitive porcine endometrial epithelial cell line by transfecting SV40 large T antigen

Generation and application of immortalized sertoli cell line from sheep testis

Primary sheep testicular Sertoli cells (STSCs) are ideal for investigating the molecular and pathogenic processes of capripoxvirus. However, the high cost of isolation and culture of primary STSCs, time-consuming operation, and short lifespan greatly limit their real-world application. In our study, the primary STSCs were isolated and immortalized by transfection of a lentiviral recombinant plasmid containing simian virus 40 (SV40) large T antigen. Androgen-binding protein (ABP) and vimentin (VIM) protein expression, SV40 large T antigen activity, proliferation assays, and apoptosis analysis results showed that immortalized large T antigen STSCs (TSTSCs) still had the same physiological characteristics and biological functions as primary STSCs. Moreover, immortalized TSTSCs had strong anti-apoptosis ability, extended lifespan, and enhanced proliferative activity compared to primary STSCs, which had not transformed in vitro and showed any signs of malignancy phenotype in nude mice. Besides, immortalized TSTSCs were susceptible to goatpox virus (GTPV), lumpy skin disease virus (LSDV), and Orf virus (ORFV). In conclusion, immortalized TSTSCs are useful in vitro models to study GTPV, LSDV, and ORFV in a wide range of ways, suggesting that it can be safely used in virus isolation, vaccine and drug screening studies in future.

Zearalenone Promotes Uterine Development of Weaned Gilts by Interfering with Serum Hormones and Up-Regulating Expression of Estrogen and Progesterone Receptors

In this study, we aimed to assess the effect of diet ZEA on serum hormones, the location and expression of estrogen receptor ERα/β and progesterone receptor (PR) of the uterus in weaned piglets and to reveal the mechanism underneath. A total of 40 healthy weaned gilts were randomly allocated to basal diet supplemented with 0 (Control), 0.5 (ZEA0.5), 1.0 (ZEA1.0) and 1.5 (ZEA1.5) mg ZEA/kg and fed individually for 35 days. Meanwhile, the porcine endometrial epithelial cells (PECs) were incubated for 24 h with ZEA at 0 (Control), 5 (ZEA5), 20 (ZEA20) and 80 (ZEA80) μmol/L, respectively. The results showed that nutrient apparent digestibility (CP and GE), nutrient apparent availability (ME/GE, BV and NPU), the uterine immunoreactive integrated optic density (IOD), relative mRNA and protein expression of ER-α, ER-β and PR and the relative mRNA and protein expression of ER-α and ER-β in PECs all increased linearly (p < 0.05) with ZEA. Collectively, ZEA can interfere with the secretion of some reproductive hormones in the serum and promote the expression of estrogen/progesterone receptors in the uterus and PECs. All these indicate that ZEA may promote the development of the uterus in weaned gilts through estrogen receptor pathway.

Establishment methods and research progress of livestock and poultry immortalized cell lines: A review

An infinite cell line is one of the most favored experimental tools and plays an irreplaceable role in cell-based biological research. Primary cells from normal animal tissues undergo a limited number of divisions and subcultures in vitro before they enter senescence and die. On the contrary, an infinite cell line is a population of non-senescent cells that could proliferate indefinitely in vitro under the stimulation of external factors such as physicochemical stimulation, virus infection, or transfer of immortality genes. Cell immortalization is the basis for establishing an infinite cell line, and previous studies have found that methods to obtain immortalized cells mainly included physical and chemical stimulations, heterologous expression of viral oncogenes, increased telomerase activity, and spontaneous formation. However, some immortalized cells do not necessarily proliferate permanently even though they can extend their lifespan compared with primary cells. An infinite cell line not only avoids the complicated process of collecting primary cell, it also provides a convenient and reliable tool for studying scientific problems in biology. At present, how to establish a stable infinite cell line to maximize the proliferation of cells while maintaining the normal function of cells is a hot issue in the biological community. This review briefly introduces the methods of cell immortalization, discusses the related progress of establishing immortalized cell lines in livestock and poultry, and compares the characteristics of several methods, hoping to provide some ideas for generating new immortalized cell lines.

Protective Effect of Resveratrol on Immortalized Duck Intestinal Epithelial Cells Exposed to H2O2

Resveratrol is a polyphenolic compound with anti-oxidation effects. The mechanisms underlying the antioxidant effects of resveratrol in duck intestinal epithelial cells remain unclear. The protective effects of resveratrol against oxidative stress induced by H2O2 on immortalized duck intestinal epithelial cells (IDECs) were investigated. IDECs were established by transferring the lentivirus-mediated simian virus 40 large T (SV40T) gene into small intestinal epithelial cells derived from duck embryos. IDECs were morphologically indistinguishable from the primary intestinal epithelial cells. The marker protein cytokeratin 18 (CK18) was also detected in the cultured cells. We found that resveratrol significantly increased the cell viability and activity of catalase and decreased the level of intracellular reactive oxygen species and malondialdehyde, as well as the apoptosis rate induced by H2O2 (p < 0.05). Resveratrol up-regulated the expression of NRF2, p-NRF2, p-AKT, and p-P38 proteins and decreased the levels of cleaved caspase-3 and cleaved caspase-9 and the ratio of Bax to Bcl-2 in H2O2-induced IDECs (p < 0.05). Our findings revealed that resveratrol might alleviate oxidative stress by the PI3K/AKT and P38 MAPK signal pathways and inhibit apoptosis by altering the levels of cleaved caspase-3, cleaved caspase-9, Bax, and Bcl-2 in IDECs exposed to H2O2.

Immortalization effect of SV40T lentiviral vectors on canine corneal epithelial cells

Background

Primary canine corneal epithelial cells (CCECs) easily become senescent, and cell proliferation is limited. Therefore, sampling for experimentation requires a large number of animals, which is problematic in terms of animal welfare and fails to maintain the stability of the cells for in vitro analyses.

Results

In this study, CCECs were separated and purified by trypsin and dispase II enzymatic analysis. Next, the cells were immortalized by transfection with a lentiviral vector expressing Simian vacuolating virus 40 large T (SV40T). The immortalized canine corneal epithelial cell line (CCEC-SV40T) was established by serial passages and monoclonal selection. The biological characteristics of CCEC-SV40T cells were evaluated based on the cell proliferation rate, cell cycle pattern, serum dependence, karyotype, and cytokeratin 12 immunofluorescence detection. In addition, we infected CCEC-SV40T cells with Staphylococcus pseudintermedius (S. pseudintermedius) and detected the inflammatory response of the cells. After the CCEC-SV40T cells were passaged continuously for 40 generations, the cells grew in a cobblestone pattern, which was similar to CCECs. The SV40T gene and cytokeratin 12 can be detected in each generation. CCEC-SV40T cells were observed to have a stronger proliferation capacity than CCECs. CCEC-SV40T cells maintained the same diploid karyotype and serum-dependent ability as CCECs. After CCEC-SV40T cells were infected with S. pseudintermedius, the mRNA expression levels of NLRP3, Caspase-1 and proinflammatory cytokines, including IL-1β, IL-6, IL-8 and TNF-α, were upregulated, and the protein levels of MyD88, NLRP3 and the phosphorylation of Iκbα and p65 were upregulated.

Conclusions

In conclusion, the CCEC-SV40T line was successfully established and can be used for in vitro studies, such as research on corneal diseases or drug screening.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03288-3.

Recent Advances in PRRS Virus Receptors and the Targeting of Receptor-Ligand for Control

Cellular receptors play a critical role in viral infection. At least seven cellular molecules have been identified as putative viral entry mediators for porcine reproductive and respiratory syndrome virus (PRRSV). Accumulating data indicate that among these candidates, CD163, a cysteine-rich scavenger receptor on macrophages, is the major receptor for PRRSV. This review discusses the recent advances and understanding of the entry of PRRSV into cells, viral pathogenesis in CD163 gene-edited swine, and CD163 as a potential target of receptor–ligand for the control of PRRS.

Roles of MOV10 in Animal RNA Virus Infection

Animal epidemic diseases caused by RNA viruses are the primary threat to the livestock industry, and understanding the mechanisms of RNA virus clearance from target cells is critical to establish an effective method to reduce economic losses. As an SF-1, ATP-dependent RNA helicase in the UPF1p family, MOV10 participates in the RNA degradation of multiple viruses mediated via miRNA pathways and therefore contributes to a decrease in the replication of RNA viruses. This review primarily focuses on the bioactivity of MOV10, the mechanism of RNA virus removal, and the potential roles of MOV10 in RNA virus clearance. In addition, clues are provided to reduce animal diseases caused by RNA viruses.

Zearalenone exposure affects the Wnt/β-catenin signaling pathway and related genes of porcine endometrial epithelial cells in vitro

Objective

Zearalenone (ZEA) has estrogen-like effects. Our previous study has shown that ZEA (0.5 to 1.5 mg/kg) could induce abnormal uterine proliferation through transforming growth factor signaling pathway. To further study the other regulatory networks of uterine hypertrophy caused by ZEA, the potential mechanism of ZEA on porcine endometrial epithelial cells (PECs) was explored by the Illumina Hiseq 2000 sequencing system.

Methods

The PECs were treated with ZEA at 0 (ZEA0), 5 (ZEA5), 20 (ZEA20), and 80 (ZEA80) μmol/L for 24 h. The collected cells were subjected to cell cycle, RNA-seq, real-time quantitative polymerase chain reaction, immunofluorescence, and western blot analysis.

Results

The proportion of cells in the S and G2 phases decreased (p<0.05), but the proportion of cells in the G1 phase increased (p<0.05) in the ZEA80 treatment. Data analysis revealed that the expression of Wnt pathway-related genes, estrogen-related genes, and mitogen-activated protein kinase pathway-related genes increased (p<0.05), but the expression of genetic stability genes decreased (p<0.05) with increasing ZEA concentrations. The relative mRNA and protein expression of WNT1, β-catenin, glycogen synthase kinase 3β (GSK-3β) were increased (p<0.05) with ZEA increasing, while the relative mRNA and protein expression of cyclin D1 (CCND1) was decreased (p<0.05). Moreover, our immunofluorescence results indicate that β-catenin accumulated around the nucleus from the cell membrane and cytoplasm with increasing ZEA concentrations.

Conclusion

In summary, ZEA can activate the Wnt/β-catenin signaling pathway by up-regulating WNT1 and β-catenin expression, to promote the proliferation and development of PECs. At the same time, the up-regulation of GSK-3β and down-regulation of CCND1, as well as the mRNA expression of other pathway related genes indicated that other potential effects of ZEA on the uterine development need further study.

Establishment of a Stable β-Casein Protein-Secreted Laoshan Dairy Goat Mammary Epithelial Cell Line

Mammary epithelial cells are widely used as models in mastitis research and as tools for mammalian bioreactors; however, the short lifespan of these cells limits their utility. Several mammal epithelial cell line models have been established; however, the secretion capacity and the bacterial sensitivity of these lines have not been effectively evaluated. In this study, a stable immortalized goat mammary epithelial cell (GMEC) line was constructed by transfection with the SV40 gene. The monoclonal cells were then passaged through more than 50 generations after puromycin selection. The GMEC line was evaluated by reverse transcriptase polymerase chain reaction, the cell cycle, karyotype analysis, detection of apoptosis, Western blotting, and β-casein (CSN2) inducible assays. The GMEC line had a strong proliferation capacity relative to the primary GMECs. GMECs had the same karyotype as the primary cells. The GMEC lines maintained basic biological properties and had estrogen, prolactin, and progesterone receptors as same the primary cells. Additionally, the cells and the cell line could synthesize and secrete β-casein proteins. Finally, the rate of apoptosis of the transfected cells suggested that the cell line could provide a useful tool for signal research and mammary gland bioreactors.