Rat-derived feeder cells immortalized by expression of mutant CDK4, cyclin D, and telomerase can support stem cell growth

Characterization of Common Minke Whale (Balaenoptera Acutorostrata) Cell Lines Immortalized with the Expression of Cell Cycle Regulators

Primary cultured cells cannot proliferate infinite. The overcoming of this limit can be classified as immortalization. Bypass of p16 senescence protein induces efficient immortalization various types of mammalians is previously reported. However, the Cetacea species is not known. Here, that common minke whale-derived cells can be immortalized with a combination of human genes, mutant cyclin-dependent kinase 4 (CDK4R24C ), cyclin D1, and Telomerase Reverse Transcriptase (TERT) is reported. These results indicate that the function of cell cycle regulators in premature senescence is evolutionarily conserved. This study describes the conserved roles of cell cycle regulators in the immortalization of cells from humans to Cetacea species. Furthermore, using RNA-seq based on next-generation sequencing, the gene expression profiles of immortalized cells are compared with parental cells as well as those immortalized with SV40 large T antigen, which is once a popular method for cellular immortalization. The profiling results show that newly established common minke-whale-derived immortaliozed cells have completely different profiles from SV40 cells. This result indicates that the expression of mutant CDK4, cyclin D1, and TERT enables to establish immortalized cell lines with different biological nature from SV40 expressing cells.

Sheep-derived cell immortalization through the expression of cell cycle regulators and biological characterization using transcriptomes

Sheep are important domestic animals for the production of wool and meat. Although numerous cultured cell lines from humans and mice have been established, the number of cell lines derived from sheep is limited. To overcome this issue, the efficient establishment of a sheep-derived cell line and its biological characterization is reported. Mutant cyclin-dependent kinase 4, cyclin D1, and telomerase reverse transcriptase were introduced into sheep muscle-derived cells in an attempt to immortalize primary cells using the K4DT method. Furthermore, the SV40 large T oncogene was introduced into the cells. The successful immortalization of sheep muscle-derived fibroblasts was shown using the K4DT method or SV40 large T antigen. Furthermore, the expression profile of established cells showed close biological characteristics of ear-derived fibroblasts. This study provides a useful cellular resource for veterinary medicine and cell biology.

Induced pluripotent stem cells of endangered avian species

The number of endangered avian-related species increase in Japan recently. The application of new technologies, such as induced pluripotent stem cells (iPSCs), may contribute to the recovery of the decreasing numbers of endangered animals and conservation of genetic resources. We established novel iPSCs from three endangered avian species (Okinawa rail, Japanese ptarmigan, and Blakiston’s fish owl) with seven reprogramming factors (M3O, Sox2, Klf4, c-Myc, Nanog, Lin28, and Klf2). The iPSCs are pluripotency markers and express pluripotency-related genes and differentiated into three germ layers in vivo and in vitro. These three endangered avian iPSCs displayed different cellular characteristics even though the same reprogramming factors use. Japanese ptarmigan-derived iPSCs have different biological characteristics from those observed in other avian-derived iPSCs. Japanese ptarmigan iPSCs contributed to chimeras part in chicken embryos. To the best of our knowledge, our findings provide the first evidence of the potential value of iPSCs as a resource for endangered avian species conservation.

iPSCs from three endangered avian species (including Okinawa rail, Japanese ptarmigan, and Blakiston’s fish owl) are developed and characterized as a potential resource for their conservation.

KAv-1 is Better Suited to Chick Fibroblast Culture than DMEM or 199 Media

Cultured cells are a useful resource for poultry scientists, since these cells allow scientists to evaluate biological responses to conditions such as infectious diseases in vitro while mimicking the whole-body response in birds. However avian cell culture requires an optimized basal medium, and there are currently relatively few options for this basal medium (medium 199 and KAv-1). This means that there is still room for the development of an optimal basal medium for avian cell culture. Here we compare KAv-1 medium, Dulbecco's modified Eagle medium (DMEM) and medium 199 during the culture of chick fibroblasts and determine that KAv-1 remains the optimal medium for these assays. Our results show that DNA damage is reduced in fibroblasts cultured in the KAv-1 medium, when compared to both DMEM and Medium 199 and that these cells also display improved growth dynamics in KAv-1 medium when compared to both DMEM and medium 199. To the best of our knowledge, this is the first study to describe a comparative analysis of culture media for avian cells, which would provide useful information for poultry scientists.

Establishment and characterization of cell lines from human endometrial epithelial and mesenchymal cells from patients with endometriosis

OBJECTIVE

To establish and characterize cell lines derived from human endometrial epithelial cells (ECs) and mesenchymal cells (MCs) from patients with and without endometriosis.

DESIGN

In vitro experimental study.

SETTING

University and national cancer center research institute.

PATIENT(S)

Two women with endometriosis and two women without endometriosis.

INTERVENTION(S)

Sampling of endometrial ECs and MCs.

MAIN OUTCOME MEASURE(S)

Establishing immortalized endometrial ECs and MCs with quantitative reverse transcription-polymerase chain reaction (qRT-PCR), immunocytochemical analysis, and RNA sequence profiling performed to characterize the immortalized cells and a cell proliferation assay, three-dimensional culture, and assays for hormone responses performed to characterize the features of ECs.

RESULT(S)

The qRT-PCR, immunocytochemical analysis, and Western blot analysis revealed that the ECs and MCs maintained their original features. Moreover, the immortalized cells were found to retain responsiveness to sex steroid hormones. The ECs formed a gland-like structure in three-dimensional culture, indicating the maintenance of normal EC phenotypes. The RNA sequence profiling, principal component analysis, and clustering analysis showed that the gene expression patterns of the immortalized cells were different from those of cancer cells. Several signaling pathways that were statistically significantly enriched in ECs and MCs with endometriosis were revealed.

CONCLUSION(S)

We successfully obtained four paired immortalized endometrial ECs and MCs from patients with and without endometriosis. Using these cells could help identify diagnostic and therapeutic targets for endometriosis. The cell lines established in this study will thus serve as powerful experimental tools in the study of endometriosis.

Generation of mouse iPS cells using an inducible expression of transgenes via the cumate gene-switch

We applied an inducible gene expression system that utilizes the p-cmt operon, the cumate gene-switch, to generate mouse induced pluripotent stem (iPS) cells. Mouse embryonic fibroblast (MEF) E6E7-MEF cells were transfected with a single cumate gene-switch vector enabling concomitant expression of Oct4, Sox2, c-Myc, Klf4, and Gfp. Then, the cells were cultured with cumate, a monoterpene. An increase in colonies positive for alkaline phosphatase activity was observed dose-dependently with cumate. In the absence of cumate, the expression of GFP, a marker for transgene expression, was undetectable in tightly aggregated iPS cell-like colonies with endogenous expression of NANOG and OCT4. From primary MEFs using the cumate gene-switch, we also isolated iPS cells expressing endogenous NANOG, OCT4, SOX2, KLF4, and SSEA1 with hypo-methylated genomic promoter regions of endogenous Nanog and Oct4. In embryoid bodies with the progression of differentiation, expression of markers for all three germ layers was detected, and contracting cardiomyocytes were observed. Overall, we suggest that the cumate gene-switch is applicable for the generation of mouse iPS cells. The cumate gene-switch in combination with other inducible systems, such as the tet system, may provide useful approaches for analyzing the roles of transgenes underlying the establishment of iPS cells.

Human Derived Immortalized Dermal Papilla Cells With a Constant Expression of Testosterone Receptor

Androgenetic alopecia (AGA) is the most common type of hair loss, and is mainly caused by the biological effects of testosterone on dermal papilla cells (DPCs). In vitro culturing of DPCs might be a useful tool for the screening of target molecule of AGA. However, primary DPCs cannot continuously proliferate owing to cellular senescence and cell culture stress. In this study, we introduced mutant cyclin-dependent kinase 4 (CDK4), Cyclin D1, and telomerase reverse transcriptase (TERT) into DPCs. We confirmed protein expression of CDK4 and Cyclin D1, and enzymatic activity of TERT. Furthermore, we found the established cell line was free from cellular senescence. We also introduced the androgen receptor gene using a recombinant retrovirus, to compensate the transcriptional suppressed endogenous androgen receptor in the process of cell proliferation. Furthermore, we detected the efficient nuclear translocation of androgen receptor into the nucleus after the treatment of dihydrotestosterone, indicating the functionality of our introduced receptor. Our established cell line is a useful tool to identify the downstream signaling pathway, which activated by the testosterone.

Establishment of immortalized primary cell from the critically endangered Bonin flying fox (Pteropus pselaphon)

The Bonin flying fox (Pteropus pselaphon) is one of the most critically endangered species of animals. The number of this species is estimated to be around 150; being classified at the top rank in the list by International Union of Animal Conservation. Our group previously showed that expression of CDK4, CYCLIN D1, and telomerase reverse transcriptase (TERT) efficiently induce immortalization of human, bovine, swine, monkey, and buffalo-derived cells. In this manuscript, we successfully established the primary cells from Bonin flying fox. We introduced CDK4, CYCLIN D1, and TERT into the primary cells. The established cells showed efficient expression of introduced genes at the protein level. Furthermore, the established cells were free from senescence, indicating it reached to immortalization. Moreover, we showed that interspecies somatic cell nuclear transfer of Bonin flying fox derived cell into bovine embryo allowed the development of the embryo to 8 cell stages. Our established cell has the potential to contribute to species conservation.