Establishment and biological characteristics of a Jingning chicken embryonic fibroblast bank

Cas9-expressing chickens and pigs as resources for genome editing in livestock

Genetically modified animals continue to provide important insights into the molecular basis of health and disease. Research has focused mostly on genetically modified mice, although other species like pigs resemble the human physiology more closely. In addition, cross-species comparisons with phylogenetically distant species such as chickens provide powerful insights into fundamental biological and biomedical processes. One of the most versatile genetic methods applicable across species is CRISPR-Cas9. Here, we report the generation of transgenic chickens and pigs that constitutively express Cas9 in all organs. These animals are healthy and fertile. Functionality of Cas9 was confirmed in both species for a number of different target genes, for a variety of cell types and in vivo by targeted gene disruption in lymphocytes and the developing brain, and by precise excision of a 12.7-kb DNA fragment in the heart. The Cas9 transgenic animals will provide a powerful resource for in vivo genome editing for both agricultural and translational biomedical research, and will facilitate reverse genetics as well as cross-species comparisons.

Proteome analysis of reticuloendotheliosis-virus-infected chicken embryo fibroblast cells through iTRAQ-based quantitative proteomics

Reticuloendotheliosis virus (REV) is an important representative avian retrovirus. To improve our understanding of the host cellular responses to virus infection and the pathogenesis of REV infection, we applied isobaric tags for relative and absolute quantification (iTRAQ) labeling coupled with multidimensional liquid chromatography-tandem mass spectrometry to detect changes in protein levels in chicken embryo fibroblast cells (CEFs) that were infected with REV or mock infected. In total, 605 cellular proteins were differentially expressed, among which 196, 345, and 286 were differentially expressed in REV-infected CEFs at 1, 3, and 5 days postinfection, respectively. Gene Ontology analysis indicated that the biological processes of the differentially expressed proteins were primarily related to cellular processes, metabolic processes, biological regulation, response to stimulus, and immune system processes and that the molecular functions in which the differentially expressed proteins were mainly involved were binding, catalytic activity, and enzyme regulator activity. Pathway analysis showed that a total of 143, 167, and 179 pathways, including protein digestion and absorption, focal adhesion, ECM-receptor interaction, cytokine-cytokine receptor interaction, Toll-like receptors, and JAK-STAT signaling, were enriched in REV-infected CEFs at 1, 3, and 5 days postinfection, respectively. In conclusion, this study is the first to analyze the protein profile of REV-infected CEFs using an iTRAQ approach. The results of this study provide valuable information for better understanding the host response to REV infection.

The biological characteristics of sheep umbilical cord mesenchymal stem cells

Although mesenchymal stem cells (MSCs) are now regarded as a promising cell resource for tissue repair and regeneration, the optimal source of MSCs has not yet been determined. The objective of this study was to provide a theoretical basis for the clinical application of umbilical cord mesenchymal stem cells (UCMSCs) in the future. Umbilical cord is an easily obtainable tissue resource, which is one reason that it has become a candidate resource for mesenchymal stem cells. In this study, we analyzed the biological characteristics of UCMSCs, such as their multiple differentiation and clone-forming ability, through morphological observation, reverse transcription polymerase chain reaction (RT-PCR), growth curve, positive rate test, and immunophenotype. Umbilical cord MSCs were successfully isolated and passaged to 29 generations. The results from RT-PCR showed that UCMSCs were positive for CD29, CD44, CD73, but negative for CD34. The expression of the stem cell marker nucleostemin and tenocyte-related markers showed similar positive results with CD44, CD73, and CD90. In addition, UCMSCs can be induced to differentiate into osteoblasts, adipocytes, or chondrocytes. Our study showed that UCMSCs not only have the ability to self-renew, but also have the potential to differentiate into multiple lineages. In general, we concluded that UCMSCs are a reliable source for use in cell therapy.

Melatonin improves reprogramming efficiency and proliferation of bovine-induced pluripotent stem cells

Melatonin can modulate neural stem cell (NSC) functions such as proliferation and differentiation into NSC-derived pluripotent stem cells (N-iPS) in brain tissue, but the effect and mechanism underlying this are unclear. Thus, we studied how primary cultured bovine NSCs isolated from the retinal neural layer could transform into N-iPS cell. NSCs were exposed to 0.01, 0.1, 1, 10, or 100 μm melatonin, and cell viability studies indicated that 10 μm melatonin can significantly increase cell viability and promote cell proliferation in NSCs in vitro. Thus, 10 μm melatonin was used to study miR-302/367-mediated cell reprogramming of NSCs. We noted that this concentration of melatonin increased reprogramming efficiency of N-iPS cell generation from primary cultured bovine NSCs and that this was mediated by downregulation of apoptosis-related genes p53 and p21. Then, N-iPS cells were treated with 1, 10, 100, or 500 μm melatonin, and N-iPS (M-N-iPS) cell proliferation was measured. We noted that 100 μm melatonin increased proliferation of N-iPS cells via increased phosphorylation of intracellular ERK1/2 via activation of its pathway in M-N-iPS via melatonin receptors 1 (MT1). Finally, we verified that N-iPS cells and M-N-iPS cells are similar to typical embryonic stem cells including the expression of pluripotency markers (Oct4 and Nanog), the ability to form teratomas in vivo, and the capacity to differentiate into all three embryonic germ layers.

Isolation and biological characterization of tendon-derived stem cells from fetal bovine

The lack of appropriate candidates of cell sources for cell transplantation has hampered efforts to develop therapies for tendon injuries, such as tendon rupture, tendonitis, and tendinopathy. Tendon-derived stem cells (TDSCs) are a type of stem cells which may be used in the treatment of tendon injuries. In this study, TDSCs were isolated from 5-mo-old Luxi Yellow fetal bovine and cultured in vitro and further analyzed for their biological characteristics using immunofluorescence and reverse transcription-polymerase chain reaction (RT-PCR) assays. It was found that primary TDSCs could be expanded for 42 passages in vitro maintaining proliferation. The expressions of stem cell marker nucleostemin and tenocyte-related markers, such as collagen I, collagen II, collagen III, and tenascin-C, were observed on different passage cells by immunofluorescence. The results from RT-PCR show that TDSCs were positive for collagen type I, CD44, tenascin-C, and collagen type III but negative for collagen type II. Meanwhile, TDSC passage 4 was successfully induced to differentiate into osteoblasts, adipocytes, and chondrocytes. Our results indicate that the fetal bovine TDSCs not only had strong self-renewal capacity but also possess the potential for multi-lineage differentiation. This study provides theoretical basis and experimental foundation for potential therapeutic application of the fetal bovine TDSCs in the treatment of tendon injuries.

Biological characterization of chicken mesenchymal stem/progenitor cells from umbilical cord Wharton's jelly

Mesenchymal stem/progenitor cells derived from Wharton's jelly of the umbilical cord (UCMSCs/UCMPCs) are multipotent, and can be differentiated in vitro into many cell types. Much work has been done on UCMSCs/UCMPCs from humans, mice, rabbits, and other mammals, but the relatively little literature has been published about these cells in chickens. In our work, we isolated USMSCs/USMPCs from chicken embryos. We characterized the isolated cells using immunofluorescence and reverse transcription polymerase chain reaction techniques. Primary UCMSCs/UCMPCs were subcultured to passage 30 and growth curves for each passage determined. The growth curves at different passages were all typically sigmoidal. Isolated UCMSCs/UCMPCs were induced to differentiate into adipocytes, osteoblasts, myocardial cells, and neural cells, and we were able to detect characteristic CD44, CD29, CD73, and CD71 cell surface markers. Our results suggest that UCMSCs/UCMPCs isolated from chickens possess similar biological characteristics to those from other species. Their multi-lineage differentiation capabilities herald a probable application for cellular transplant therapy in tissue engineering.

On the future contents of a small journal of histochemistry

In the last three years, more than 70,000 scientific articles have been published in peer reviewed journals on the application of histochemistry in the biomedical field: most of them did not appear in strictly histochemical journals, but in others dealing with cell and molecular biology, medicine or biotechnology. This proves that histochemistry is still an active and innovative discipline with relevance in basic and applied biological research, but also demonstrates that especially the small histochemical journals should likely reconsider their scopes and strategies to preserve their authorship. A review of the last three years volumes of the European Journal of Histochemistry, taken as an example of a long-time established small journal, confirmed that the published articles were widely heterogeneous in their topics and experimental models, as in this journal's tradition. This strongly suggests that a journal of histochemistry should keep its role as a forum open to an audience as broad as possible, publishing papers on cell and tissue biology in a wide variety of models. This will improve knowledge of the basic mechanisms of development and differentiation, while helping to increase the number of potential authors since scientists who generally do not use histochemistry in their research will find hints for the applications of histochemical techniques to novel still unexplored subjects.