Immortalization by large T-antigen of the adult epididymal duct epithelium

Characterization of a Human Gastrointestinal Stromal Tumor Cell Line Established by SV40LT-Mediated Immortalization

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in the digestive tract and originate from the interstitial cells of Cajal (ICC), which is the pacemaker for peristaltic movement in the gastrointestinal tract. Existing GIST cell lines are widely used as cell models for in vitro experimental studies because the mutation sites are known. However, the immortalization methods of these cell lines are unknown, and no Chinese patient-derived GIST cell lines have been documented. Here, we transfected simian virus 40 large T antigen (SV40LT) into primary GIST cells to establish an immortalized human GIST cell line (ImGIST) for the first time. The ImGIST cells had neuronal cell-like irregular radioactive growth and retained the fusion growth characteristics of GIST cells. They stably expressed signature proteins, maintained the biological and genomic characteristics of normal primary GIST cells, and responded well to imatinib, suggesting that ImGIST could be a potential in vitro model for research in GIST to explore the molecular pathogenesis, drug resistance mechanisms, and the development of new adjuvant therapeutic options.

Molecular phenotyping uncovers differences in basic housekeeping functions among closely related species of hares ( Lepus spp., Lagomorpha: Leporidae)

Speciation is a fundamental evolutionary process, which results in genetic differentiation of populations and manifests as discrete morphological, physiological and behavioural differences. Each species has travelled its own evolutionary trajectory, influenced by random drift and driven by various types of natural selection, making the association of genetic differences between the species with the phenotypic differences extremely complex to dissect. In the present study, we have used an in vitro model to analyse in depth the genetic and gene regulation differences between fibroblasts of two closely related mammals, the arctic/subarctic mountain hare (Lepus timidus Linnaeus) and the temperate steppe-climate adapted brown hare (Lepus europaeus Pallas). We discovered the existence of a species-specific expression pattern of 1623 genes, manifesting in differences in cell growth, cell cycle control, respiration, and metabolism. Interspecific differences in the housekeeping functions of fibroblast cells suggest that speciation acts on fundamental cellular processes, even in these two interfertile species. Our results help to understand the molecular constituents of a species difference on a cellular level, which could contribute to the maintenance of the species boundary.

Established Liver Cell Lines: Are You Sure to Have the Right Ones?

In liver research, immortalized cell lines have assumed an important role in studying general physiological and pathological processes. However, misidentification and cross-contamination of cell lines is a widespread problem in biomedical sciences resulting in irreproducible results and false conclusions. Although the huge impact of working with wrong cell lines on life science research and publication has been well recognized, there are only limited efforts and strategies to prevent cell misidentification. This commentary provides a catalogue of the most important cell lines used in hepatology research, examples of misidentified cell lines, and short guidelines to be considered when working with continuous lines.

Generation and characterization of genome-modified chondrocyte-like cells from the zebra finch cell line immortalized by c-MYC expression

BACKGROUND

Due to their cost effectiveness, ease of use, and unlimited supply, immortalized cell lines are used in place of primary cells for a wide range of research purposes, including gene function studies, CRISPR-based gene editing, drug metabolism tests, and vaccine or therapeutic protein production. Although immortalized cell lines have been established for a range of animal species, there is still a need to develop such cell lines for wild species. The zebra finch, which is used widely as a model species to study the neurobiological basis of human speech disorders, has been employed in several functional studies involving gene knockdown or the introduction of exogenous transgenes in vivo; however, the lack of an immortalized zebra finch cell line has hampered precise genome editing studies.

RESULTS

Here, we established an immortalized cell line by a single genetic event, expression of the c-MYC oncogene, in zebra finch embryonic fibroblasts and examined its potential suitability for gene targeting investigations. Retroviral vector-mediated transduction of c-MYC was used to immortalize zebra finch primary fibroblasts; the transformed cells proliferated stably over several passages, resulting in the expression of chondrocyte-specific genes. The transfection efficiency of the immortalized cells was much higher than that of the primary cells. Targeted knockout of the SOX9 gene, which plays a role in the differentiation of mesenchymal progenitor cells into chondrocytes, was conducted in vitro and both apoptosis and decreased expression levels of chondrogenic marker genes were observed in edited cells.

CONCLUSIONS

The c-MYC induced immortalized chondrocyte-like cell line described here broadens the available options for establishing zebra finch cell lines, paves the way for in-depth biological researches, and provides convenient approaches for biotechnology studies, particularly genomic modification research.

A novel cell line from human eccrine sweat gland duct cells for investigating sweating physiology

OBJECTIVE

Human eccrine sweat glands represent vital components of the skin involved in regulating body temperature. Especially the eccrine duct, which opens directly into the skin surface and releases the aqueous sweat, constitutes the first contact point with topically applied substances. For scientific investigations and to understand the underlying sweating mechanism on a cellular level defined cellular material is beneficial. We, therefore, strived to generate a cell line derived from human eccrine sweat gland duct cells for identifying new mechanisms in sweating control, as such a standardize cell line is currently lacking.

MATERIAL AND METHODS

Isolated primary human eccrine sweat gland duct cells were transduced with simian virus 40 large T antigen (SV40T) by lentiviral transduction. Successfully SV40T-transduced clones were selected by single cell cloning with one clone, named 1D10, being particularly described in this work.

RESULTS

In performed cellular investigations, SV40T-transduced duct-derived cells exhibited an extended lifespan with stable population doubling times suggesting its immortality. Besides, 1D10 clonal cell culture demonstrated similarities with parental, primary duct cells regarding gene expression of selected sweat gland-related markers. When combined with primary coil cells in a hanging drop co-culture, those transduced duct-derived cells showed some duct cell-like features. Further, a certain degree of cellular communication and a specific reaction towards substance application was observed.

CONCLUSION

Generated and herein described cell line derived from isolated human eccrine sweat gland duct cells is, based on the presented scientific findings, considered as immortal. Besides, this cell line shows some similarity with primary duct cells, although alterations from native glands were detected, among which is loss of expression of CFTR. Provided some further investigations, presented SV40T-transduced duct-cell derived cell line seems a suited surrogate of primary eccrine duct cells.

Polarized epithelium-sperm co-culture system reveals stimulatory factors for the secretion of mouse epididymal quiescin sulfhydryl oxidase 1

Spermatozoa acquire fertilization ability through post-translational modifications. These membrane surface alterations occur in various segments of the epididymis. Quiescin sulfhydryl oxidases, which catalyze thiol-oxidation reactions, are involved in disulfide bond formation, which is essential for sperm maturation, upon transition and migration in the epididymis. Using castration and azoospermia transgenic mouse models, in the present study, we showed that quiescin sulfhydryl oxidase 1 (QSOX1) protein expression and secretion are positively correlated with the presence of testosterone and sperm cells. A two-dimensional in vitro epithelium-sperm co-culture system provided further evidence in support of the notion that both testosterone and its dominant metabolite, 5α-dihydrotestosterone, promote epididymal QSOX1 secretion. We also demonstrated that immature caput spermatozoa, but not mature cauda sperm cells, exhibited great potential to stimulate QSOX1 secretion in vitro, suggesting that sperm maturation is a key regulatory factor for mouse epididymal QSOX1 secretion. Proteomic analysis identified 582 secretory proteins from the co-culture supernatant, of which 258 were sperm-specific and 154 were of epididymal epithelium-origin. Gene Ontology analysis indicated that these secreted proteins exhibit functions known to facilitate sperm membrane organization, cellular activity, and sperm-egg recognition. Taken together, our data demonstrated that testosterone and sperm maturation status are key regulators of mouse epididymal QSOX1 protein expression and secretion.

A novel use for Levey-Jennings charts in prenatal molecular diagnosis

Background

The goal of this study was to determine whether Levey-Jennings charts, which are widely used in clinical laboratories, can be used to create standardized internal quality controls (IQCs) for prenatal molecular diagnosis.

Methods

Aneuploid amniocyte lines with trisomy 13, 21, and 18, and 47,XXY were established by transfection with SV40LTag-pcDNA3.1(−)and combined at different ratios to generate aneuploidy chimeric quality-control cell mixtures A to H. These quality-control cells were then used to calculate the \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \overline{\mathrm{X}} $$\end{document}X¯, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \overline{\mathrm{X}} $$\end{document}X¯ ±1 standard deviation (SD), \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \overline{\mathrm{X}} $$\end{document}X¯ ±2 SD, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \overline{\mathrm{X}} $$\end{document}X¯ ±3 SD values to develop standardized IQCs for methods used for the prenatal diagnosis of aneuploidies such as FISH.

Results

Methods for constructing aneuploid amniocyte lines were developed and a set of quality-control cells (A-H) were prepared. The \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \overline{\mathrm{X}} $$\end{document}X¯ ±1 SD, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \overline{\mathrm{X}} $$\end{document}X¯ ±2 SD, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \overline{\mathrm{X}} $$\end{document}X¯ ±3 SD values of these quality-control cells for trisomy 13 and 21 were 10.2 ± 1.7, 10.2 ± 3.4, and 10.2 ± 5.1, and 90.3 ± 2.3, 90.3 ± 4.6, and 90.3 ± 6.9, respectively. Based on the values and Levey-Jennings charts, a set of standardized IQCs for prenatal diagnosis such as FISH were established.

Conclusions

This method resolves the problems of a shortage of quality-control materials and a lack of quality-control charts in prenatal molecular diagnosis such as NIPT, NGS, aCGH/SNP, PCR, and FISH. Levey-Jennings chart-based IQCs for prenatal diagnosis such as FISH can be used to easily monitor whether IQC results are within acceptable limits, and then infer whether the diagnostic results for clinical samples are reliable. We expect that this standardized IQC will be useful for a wide range of molecular diagnostic laboratories.

Production of functional eggs and sperm from in vitro-expanded type A spermatogonia in rainbow trout

Combining cryopreservation of germline stem cells (GSCs) with their subsequent transplantation into recipient fish is a powerful tool for long-term preservation of genetic resources of endangered fishes. However, application of this technique has been limited because endangered species sometimes have small gonads and do not supply enough GSCs to be used for transplantation. This limitation could be overcome by expanding GSCs in vitro, though this has been difficult due to the complexity of reconstructing the gonadal microenvironment that surrounds GSCs. Here, we describe a novel method of in vitro expansion of rainbow trout GSCs using a feeder layer derived from Sertoli cells and a culture medium containing trout plasma. A transplantation assay demonstrated that the in vitro-expanded GSCs exhibited stem cell activity and potency to produce functional eggs, sperm, and eventually healthy offspring. In vitro expansion of GSCs can aid in rescuing fishes that are on the verge of extinction.

Creation and characterization of an immortalized canine myoblast cell line: Myok9

The availability of an in vitro canine cell line would reduce the need for dogs for primary in vitro cell culture and reduce overall cost in pre-clinical studies. An immortalized canine muscle cell line, named Myok9, from primary myoblasts of a normal dog has been developed by the authors. Immortalization was performed by SV40 viral transfection of the large T antigen into the primary muscle cells. Proliferation assays, growth curves, quantitative PCR, western blotting, mass spectrometry, and light microscopy were performed to characterize the MyoK9 cell line at different stages of growth and differentiation. The expression of muscle-related genes was determined to assess myogenic origin. Myok9 cells expressed dystrophin and other muscle-specific proteins during differentiation, as detected with mass spectrometry and western blotting. Using the Myok9 cell line, new therapies before moving to pre-clinical studies to enhance the number and speed of analyses and reduce the cost of early experimentation can be tested now. This cell line will be made available to the research community to further evaluate potential therapeutics.

Cyclic GMP-AMP synthase is essential for cytosolic double-stranded DNA and fowl adenovirus serotype 4 triggered innate immune responses in chickens

Cyclic GMP-AMP (cGAMP) synthase (cGAS) is a predominant DNA sensor inducing the activation of the innate immune responses that produce proinflammatory cytokines and type I interferons, which has been well-investigated in mammals. However, chicken cGAS (chcGAS), which participates in avian innate immunity, has not been well-investigated. Here, we cloned the complete open reading frame sequence of chcGAS. Multiple sequence alignment and phylogenetic analysis revealed that chcGAS was homologous to mammalian cGAS. The chcGAS mRNA was highly expressed in the bone marrow and ileum. The subcellular localization of chcGAS was mainly in the cytoplasm, and partial co-localization was observed in the endoplasmic reticulum. Through overexpression and RNA interference, we demonstrated that chcGAS responded to exogenous dsDNA, HS-DNA, and poly(dA:dT), and to self dsDNA from the DNA damage response, thereby triggering the activation of STING/TBK1/IRF7-mediated innate immunity in both chicken embryonic fibroblasts and chicken liver cancer cells. Furthermore, downregulation of chcGAS enhanced the infection of fowl adenovirus serotype 4 in LMH cells. Our results demonstrated that chcGAS was an important cytosolic DNA sensor activating innate immune responses and may shed light on a strategy for preventing infectious diseases in the poultry industry.

Traditional and Advanced Cell Cultures in Hematopoietic Stem Cell Studies

Hematopoiesis is the main function of bone marrow. Human hematopoietic stem and progenitor cells reside in the bone marrow microenvironment, making it a hotspot for the development of hematopoietic diseases. Numerous alterations that correspond to disease progression have been identified in the bone marrow stem cell niche. Complex interactions between the bone marrow microenvironment and hematopoietic stem cells determine the balance between the proliferation, differentiation and homeostasis of the stem cell compartment. Changes in this tightly regulated network can provoke malignant transformation. However, our understanding of human hematopoiesis and the associated niche biology remains limited due to accessibility to human material and the limits of in vitro culture models. Traditional culture systems for human hematopoietic studies lack microenvironment niches, spatial marrow gradients, and dense cellularity, rendering them incapable of effectively translating marrow physiology ex vivo. This review will discuss the importance of 2D and 3D culture as a physiologically relevant system for understanding normal and abnormal hematopoiesis.

Desirable quality-control materials for the establishment of qualified external quality assessment on prenatal diagnosis of chromosomal aneuploidies

OBJECTIVE

To prepare desirable quality-control materials for the establishement of qualified external quality assessment on fluorescence in situ hybridization (FISH)-detected prenatal diagnosis of chromosomal aneuploidies.

METHODS

Four types of amniotic fluid cell suspensions (13-trisomy, 18-trisomy, 21-trisomy and 47,XXY) were mixed together by ratio to produce mosaicism with the percentages of each aneuploidy as 10%, 20%, 30% and 40%, respectively. After being stored in liquid nitrogen of -196 °C for six months, randomly selected samples were incubated in 37 °C water, followed by cultivation, hypo-osmosis and fixation. Finally, FISH detetion was applied on them before and after external laboratory mailing, in step with detection on conventional case samples.

RESULTS

Before mailing, the positive rates of each aneuploidy described above were 12.8%, 23.6%, 33.8%, 44.0%, while 12.6%, 23.8%, 34.0%, 43.5% after mailing. t-test, criteria for stability assessment of quality-control materials in CANS-GL03:2006, showed no significant effect of external mailing on mosaicism since corresponding t values are lower than threshold with significance level α as 0.05 and degree of freedom as 10.

CONCLUSION

As FISH detection showed, the mosaic cell strains prepared in current study exhibited excellent stabilities after cryopreservation in -196 °C, subculture, hypo-osmosis, fixation and external laboratory mailing, demonstrating them as reliable and promising quality-control materials for the establishment of a qualified external quality assessment on prenatal diagnosis of chromosomal aneuploidies.

Immortalized porcine mesenchymal cells derived from nasal mucosa, lungs, lymph nodes, spleen and bone marrow retain their stemness properties and trigger the expression of siglec-1 in co-cultured blood monocytic cells

Mesenchymal stromal cells have been isolated from different sources. They are multipotent cells capable of differentiating into many different cell types, including osteocytes, chondrocytes and adipocytes. They possess a therapeutic potential in the management of immune disorders and the repair of damaged tissues. Previous work in our laboratory showed an increase of the percentages of CD172a⁺, CD14⁺, CD163⁺, Siglec-1⁺, CD4⁺ and CD8⁺ hematopoietic cells, when co-cultured with immortalized mesenchymal cells derived from bone marrow. The present work aimed to demonstrate the stemness properties of SV40-immortalized mesenchymal cells derived from nasal mucosa, lungs, spleen, lymph nodes and red bone marrow and their immunomodulatory effect on blood monocytes. Mesenchymal cells from nasal mucosa, lungs, spleen, lymph nodes and red bone marrow were isolated and successfully immortalized using simian virus 40 large T antigen (SV40LT) and later, co-cultured with blood monocytes, in order to examine their differentiation stage (expression of Siglec-1). Flow cytometric analysis revealed that the five mesenchymal cell lines were positive for mesenchymal cell markers CD105, CD44, CD90 and CD29, but lacked the expression of myeloid cell markers CD16 and CD11b. Growth analysis of the cells demonstrated that bone marrow derived-mesenchymal cells proliferated faster compared with those derived from the other tissues. All five mesenchymal cell lines co-cultured with blood monocytes for 1, 2 and 7 days triggered the expression of siglec-1 in the monocytes. In contrast, no siglec-1⁺ cells were observed in monocyte cultures without mesenchymal cell lines. Mesenchymal cells isolated from nasal mucosa, lungs, spleen, lymph nodes and bone marrow were successfully immortalized and these cell lines retained their stemness properties and displayed immunomodulatory effects on blood monocytes.

Attempts on producing lymphoid cell line from Penaeus monodon by induction with SV40-T and 12S EIA oncogenes

In an attempt of in vitro transformation, transfection mediated expression of Simian virus-40 (T) antigen (SV40-T) and transduction mediated expression of Adenovirus type 12 early region 1A (12S E1A) oncogene were performed in Penaeus monodon lymphoid cells. pSV3-neo vector encoding SV40-T oncogene and a recombinant baculovirus BacP2-12S E1A-GFP encoding 12S E1A oncogene under the control of hybrid promoters were used. Electroporation and lipofection mediated transformation of SV40-T in lymphoid cells confirmed the transgene expression by phenotypic variation and the expression of GFP in co-transfection experiment. The cells transfected by lipofection (≥ 5%) survived for 14 days with lower toxicity (30%), whilst on electroporation, most of the cells succumbed to death (60%) and survived cells lived up to 7 days. Transduction efficiency in primary lymphoid cells was more than 80% within 14 days of post-transduction, however, an incubation period of 7 days post-transduction was observed without detectable expression of 12S E1A. High level of oncogenic 12S E1A expression were observed after 14 day post-transduction and the proliferating cells survived for more than 90 days with GFP expression, however, without in vitro transformation and immortalization. The study put forth the requirement of transduction mediated 'specific' oncogene expression along with telomerase activation and epigenetic induction for the immortalization and establishment of shrimp cell line.

Immortalised human mesenchymal stem cells undergo chondrogenic differentiation in alginate and PGA/PLLA scaffolds

Adult mesenchymal stem cells (MSCs) are a promising cell source in tissue engineering due to their availability, ease of isolation and high proliferative activity. This study was undertaken to investigate whether immortalised human MSC are able to undergo chondrogenic differentiation when cultured in alginate or in resorbable scaffolds. We directly compared chondrogenesis MSCs with that of human nasoseptal chondrocytes. Two previously established human stem cell lines L87/4 and V54-2 immortalised using the SV40 large T-antigen were either cultured in alginate or in polyglycolic acid/poly-L-lactic acid (PGA/PLLA) (90/10) copolymer scaffolds. TGF-β1 was added for induction of chondrogenesis. Human nasoseptal chondrocytes and human fibroblasts were used as controls. Cultures were analysed for sulfated glycosaminoglycans (alcian blue staining) and for the presence of collagen type I, II and X (immunolabelling). SV40 large T-antigen immortalised human MSCs have the potential to undergo chondrogenic differentiation: After 21 days, cartilage-specific type II collagen was present in alginate and PGA/PLLA scaffolds, independent of the addition of TGF-β1. Collagen type X was present in monolayer cultures as well as in alginate and PGA/PLLA scaffolds. Collagen type I was produced in marginal amounts only. Immortalised human MSCs are a suitable tool to study chondrogenesis in vitro and to screen biomaterials for cartilage tissue engineering applications.

Construction and identification of ATP4B-SV40T-IRES-GFP transgenic vector

AIM: To construct and identify ATP4B-SV40T-IRES-GFP transgenic vector.

METHODS: The mouse ATP4B gene promoter was amplified and inserted into IRES-GFP vector after the addition of restriction enzyme sites to result in ATP4B-IRES-GFP. After restriction enzyme digestion, the SV40T gene sequence was inserted into ATP4B-IRES-GFP. The resultant recombinant plasmid was identified by digestion with restriction enzymes PstI and AseⅠ.

RESULTS: The recombinant plasmids ATP4B-IRES-GFP and ATP4B-SV40T-IRES-GFP have been successfully constructed and can be used to generate transgenic mice.

CONCLUSION: The recombinated plasmid ATP4B-SV40T-IRES-GFP was constructed successfully and it could be used to construct the transgenic mice with primary gastric cancer.

Connexins and pannexins: Coordinating cellular communication in the testis and epididymis

Gap junctions and connexins are critical for coordinating cellular functions in complex epithelia. In recent years there has been increased interest in understanding the regulation and function of gap junctions in both the testis and epididymis. Studies in transgenic mice in which connexin 43 (Cx43) is mutated or is knocked down only in Sertoli cells have demonstrated the essential role of Cx43 in spermatogenesis and differentiation of Sertoli cells. In the epididymis developmental studies have shown a role for numerous connexins in the differentiation of epithelial cells and communication between the basal cells and both principal and clear cells. In both tissues several factors, such thyroid hormones and androgens, are important in regulating expression and function of connexins. Pannexins, which form cellular channels but are structurally similar to gap junction proteins, have been identified in both testis and epididymis and, in the epididymis, are regulated by androgens. The objective of this review is to summarize the advances that have been made on the role and regulation of connexins and pannexins in the testis and epididymis and their implication in spermatogenesis and sperm maturation.

Gene transfer to the mammalian reproductive tract

This review summarizes the results of research on gene transfer to the mammalian genital tract. Gene transfer experiments have been developed during the last 2 decades and have been applied using in vitro, ex vivo and in vivo procedures. (i) In vitro methods have been applied to the uterine epithelial cells with the principal purpose of analysing some pathological change occurring in the uterus. In the male tract, epididymal cell lines have been used to evaluate the expression of particular genes and the function of specific proteins. (ii) Ex vivo methods have been applied to both the uterus and the vas deferens in humans, and good transgene expression has been recorded. (iii) In vivo gene transfer in the female tract has been employed in the uterus and oviduct using gene injections or electroporation methods. The glandular epithelium of both organs can be transfected efficiently, and transfection efficiency depends on the hormonal stage of the animal. The best expression occurred during pseudopregnancy and meta-estrus periods, when high progesterone and low estradiol concentrations occur. In the male tract, in vivo methods have been applied to mouse vas deferens and epididymis. In both organs, patches of epithelial regions appeared to express the transgenes. Furthermore, the secretions of both organs were also modified using gene constructions that led to the expression of some secretory proteins. In summary, gene modifications in the epithelium of the mammalian reproductive tract have been successful employing different technologies. Further improvements in transfection efficiency would help provide new insights into the physiology of these reproductive organs. Furthermore, the use of these methods could also be used to modify the fertility of mammals.

Immortalization of human precartilaginous stem cells by transfecting SV40Tag

Immortalized human precartilaginous stem cells (IPSCs) were established to provide stable cell resource for the study of the molecular mechanism of gene targeting on the differentiation of PSCs. Plasmid pCMVSV40T/PUR containing simian virus 40 large T antigen gene (SV40Tag) was transfected into human PSCs by using lipofectin transfection. Colonies were isolated by puromycin selection and expanded by multiple passages. Immunohistochemistry, RT-PCR and Southern blotting were used to identify the transfected cells and to detect the expression and integration of SV40Tag in expanded cell lines. The positive colonies were isolated and subcultured, designated immortalized precartilaginous stem cells (IPSCs), which were confirmed as fibroblast growth factor receptor-3 (FGFR-3) positive cells by immunohistochemistry and RT-PCR. SV40Tag cDNA was found in cultured IPSCs of passage 8 by Southern blotting, and the expressions of SV40Tag mRNA and protein were confirmed by RT-PCR. These findings suggested that IPSCs strain with SV40Tag was constructed successfully.

In-vivo gene transfer induces transgene expression in cells and secretions of the mouse cauda epididymis

Mouse cauda epididymis were in-vivo transfected using the lipid FuGENE 6 as gene vector. Two gene constructions were employed: the p-GeneGRIP which codifies for the Green Fluorescent Protein (GFP) and the pSEAP-control that expresses an alkaline phosphatase as a secretion. Transfection was detected by fluorescence and appeared in the nucleus and cytoplasm of epithelial cells. Transfection was observed in 39.70% of cells after 2 days and in 31.77% after 7 days, and then diminished progressively. Moreover, the presence of the transgene in the DNA isolated from treated epididymides was observed by polymerase chain reaction. GFP gene expression appeared in large areas of the cauda epididymis and it was observed exclusively in the cytoplasm of epithelial cells. GFP gene expression occurred during 2 weeks after gene injection and occupied 32.24, 29.98 and 22.37% of the area of the tubules when analyzed 2, 7 and 15 days after gene injection. The cauda was also analyzed in toto and showed similar results. The use of the pSEAP-control gene showed that cauda epididymis secretions can also be modified by the transfection procedure. A significant increase of alkaline phosphatase activity appeared in the epididymal fluids 7 days after gene injection. These results indicate that transfection procedures could be an important tool in the future to study epididymal physiology or to change the fertilizing ability of spermatozoa.

Establishment of immortalized rat Kupffer cell lines

BACKGROUND

Kupffer cells have been implicated in the pathogenesis of various liver diseases. Primary cultures of Kupffer cells have a very limited life span, tend to de-differentiate and become senescent, and therefore are not suitable for cell signaling studies.

AIM

To establish immortalized rat Kupffer cell lines that facilitate mechanistic studies of cell signaling and signal transduction.

METHODS

Rat Kupffer cells were sub-cultured with EGF to obtain rat Kupffer Cell line 1 (RKC1), and subsequently transfected with Simian Virus 40 Large T-antigen expression vector to obtain rat Kupffer Cell line 2 (RKC2).

RESULTS

RKC1 and RKC2 are similar to primary Kupffer cells as they express the molecular markers ED1, ED2, ED3, and F4/80, and upregulate TNF-alpha, IL-6, IL-1beta, Fas /FasL, and NF-kappaB, as well as TLR4 in response to LPS or pancreatic elastase. Additionally, RKC1 and RKC2 maintain phagocytic properties of latex beads and exhibit increased telomerase and stabilized p53 activity.

CONCLUSION

Immortalized RKC1 and RKC2 cells maintain properties of primary Kupffer cells and can be valuable tools in evaluating the role of Kupffer cells in immune diseases and in liver-cell based drug discovery.

Characterization of a novel rat epididymal cell line to study epididymal function

The epididymis is an androgen-dependent organ that allows spermatozoa to become fully functional as they pass through this tissue. The specialized functions of the epididymis are mediated by interactions between epididymal epithelial cells and between epididymal cells and spermatozoa. Although the critical role of the epididymis in sperm maturation is well established, the mechanisms regulating cell-cell interactions remain poorly understood because of the lack of appropriate cell line models. We now report the characterization of a novel rat caput epididymal cell line (RCE) that was immortalized by transfecting primary cultures of rat epididymal cells with the simian virus 40 large T antigen. At the electron microscope level, the cell line was composed of epithelial principal cells with characteristics of in vivo cells; principal cells had well-developed Golgi apparatus, abundant endoplasmic reticulum cisternae, and few endosomes. RCE cells expressed the mRNAs coding for the androgen receptor, estrogen receptor alpha, and 4-ene-steroid-5-alpha-reductase types 1 and 2 as well as epididymal-specific markers Crisp-1 and epididymal retinoic acid binding protein. Epididymal retinoic acid binding protein expression was significantly induced with dihydrotestosterone, although this effect was not blocked by flutamide, suggesting that RCE cells are not androgen responsive. Neighboring cells formed tight and gap junctions characteristic of epididymal cells in vivo and expressed tight (occludin and claudin-1, -3, and -4) and gap junctional proteins (connexin-26, -30.3, -32, and -43). The RCE cell line displays many characteristics of epithelial principal cells, thus providing a model for studying epididymal cell functions.

Functional characterization of a conditionally immortalized mouse epididymis caput epithelial cell line MEPC5 using temperature-sensitive simian virus 40 large T-antigen

A conditionally immortalized epididymis caput cell line, MEPC5, was established by infecting primary cultured mouse epididymis caput cells with a temperature-sensitive simian virus 40 large T-antigen. At a permissive temperature of 33 degrees C, the large T-antigen was expressed and the cells grew continuously. However, the downregulation of T-antigen at a nonpermissive temperature of 39 degrees C and the upregulation of cell density at 33 degrees C were associated with growth arrest and the increased protein expression of p21(waf1), a cell cycle inhibitor. The cells expressed epididymal caput-expressed genes such as phosphatidylethanolamine binding protein, polyoma enhancer activator 3, ME1, sulfated glycoprotein-2 (SGP-2), androgen receptor, and retinoic acid receptor alpha. Interestingly, the expression levels of ME1 and SGP-2 were significantly elevated under the cell growth-restricted conditions. The established mouse epididymis caput epithelial cell line MEPC5 retains some characteristics of differentiated epididymis epithelial cells, and should prove an excellent model for studies of gene expression and the physiological functions of epididymis caput epithelial cells.

Spontaneously immortalized epithelial cells from mouse caput epididymidis

We report here on the characterization of tissue-culture cell lines derived from primary cultures of the mouse caput epididymidis epithelium. The cell lines were spontaneously immortalized without the use of transforming oncogenes. In defined conditions, our epididymal cells adopted various morphological features that resembles that of the in vivo epididymis epithelium such as a polarized organization and the presence of junctional structures at their apical/lateral membranes as revealed by electron microscopy analyses. Flow cytometry analysis revealed that we were dealing with homogenous cell populations that had reached a near-tetraploid state. RT-PCR assays were used in order to show that several genes that can be considered as markers of in vivo caput epididymidis epithelium activity were expressed in our cell lines confirming that these cells were indeed in a differentiated state close to their endogenous state.