Primate Fibroblasts Research Articles

Nanopore Assay Reveals Cell-Type-Dependent Gene Expression of Vesicular Stomatitis Indiana Virus and Differential Host Cell Response.

Vesicular stomatitis Indiana virus (VSIV) of genus Vesiculovirus, species Indiana Vesiculovirus (formerly as Vesicular stomatitis virus, VSV) causes a disease in livestock that is very similar to the foot and mouth disease, thereby an outbreak may lead to significant economic loss. Long-read sequencing (LRS) -based approaches already reveal a hidden complexity of the transcriptomes in several viruses. This technique has been utilized for the sequencing of the VSIV genome, but our study is the first for the application of this technique for the profiling of the VSIV transcriptome. Since LRS is able to sequence full-length RNA molecules, it thereby provides more accurate annotation of the transcriptomes than the traditional short-read sequencing methods. The objectives of this study were to assemble the complete transcriptome of using nanopore sequencing, to ascertain cell-type specificity and dynamics of viral gene expression, and to evaluate host gene expression changes induced by the viral infection. We carried out a time-course analysis of VSIV gene expression in human glioblastoma and primate fibroblast cell lines using a nanopore-based LRS approach and applied both amplified and direct cDNA sequencing (as well as cap-selection) for a fraction of samples. Our investigations revealed that, although the VSIV genome is simple, it generates a relatively complex transcriptomic architecture. In this study, we also demonstrated that VSIV transcripts vary in structure and exhibit differential gene expression patterns in the two examined cell types.

Conversion of monkey fibroblasts to transplantable telencephalic neuroepithelial stem cells

Non-human primates provide optimal models for the development of stem cell therapies. Although somatic cells have been converted into neural stem/progenitor cells, it is unclear whether telencephalic neuroepithelial stem cells (NESCs) with stable properties can be generated from fibroblasts in primate. Here we report that a combination of transcription factors (Oct4, Sox2, Klf4) with a new culture medium induces rhesus monkey fibroblasts into NESCs, which can develop into miniature neural tube (NT)-like structures at a cell level. Furthermore, single induced NESCs (iNESCs) can generate later-stage 3D-NTs after grown on matrigel in suspension culture. iNESCs express NT cell markers, have a unique gene expression pattern biasing towards telencephalic patterning, and give rise to cortical neurons. Via transplantation, single iNESCs can extensively survive, regenerate myelinated neuron axons and synapse structures in adult monkey striatum and cortex, and differentiate into cortical neurons. Successful transplantation is closely associated with graft regions and grafted cell identities. The ability to generate defined and transplantable iNESCs from primate fibroblasts under a defined condition with predictable fate choices will facilitate disease modeling and cell therapy.

Non-human Primate and Rat Cardiac Fibroblasts Show Similar Extracellular Matrix-related and Cellular Adhesion Gene Responses to Substance P

The sensory nerve neuropeptide substance P (SP) regulates cardiac fibrosis in rodents under pressure overload conditions. Interestingly, SP induces transient increased expression of specific genes in isolated rat cardiac fibroblasts, without resultant changes in cell function. This suggests that SP 'primes' fibroblasts, but does not directly activate them. We investigated whether these unusual findings are specific to rodent fibroblasts or are translatable to a larger animal model more closely related to humans. We compared the effects of SP on genes associated with extracellular matrix (ECM) regulation, cell-cell adhesion, cell-matrix adhesion and ECM in cardiac fibroblasts isolated from a non-human primate and Sprague-Dawley rats. We found that rodent and non-human primate cardiac fibroblasts showed similar responses in genes that relate to ECM regulation and cell adhesion in response to SP. There were large discrepancies in ECM component genes, however, this did not result in collagen or laminin synthesis in rat or non-human primate fibroblasts in response to SP. This study further supports the notion that SP serves as a 'primer' for fibroblasts rather than initiating direct effects and suggests that rodent fibroblasts are a suitable model for studying gene and functional responses to SP in the absence of human or non-human primate fibroblasts.

Generation of Integration-free and Region-Specific Neural Progenitors from Primate Fibroblasts

Postnatal and adult human and monkey fibroblasts were infected with Sendai virus containing the Yamanaka factors for 24hr, then they were cultured in a chemically defined medium containing leukemia inhibitory factor (LIF), transforming growth factor (TGF)-β inhibitor SB431542, and glycogen synthase kinase (GSK)-3β inhibitor CHIR99021 at 39°C for inactivation of the virus. Induced neural progenitor (iNP) colonies appeared as early as day 13 and can be expanded for >20 passages. Under the same defined condition, no induced pluripotent stem cell (iPSC) colonies formed at either 37°C or 39°C. The iNPs predominantly express hindbrain genes and differentiate into hindbrain neurons, and when caudalized, they produced an enriched population of spinal motor neurons. Following transplantation into the forebrain, the iNP-derived cells retained the hindbrain identity. The ability to generate defined, integration-free iNPs from adult primate fibroblasts under a defined condition with predictable fate choices will facilitate disease modeling and therapeutic development.

Testing the oxidative stress hypothesis of aging in primate fibroblasts: is there a correlation between species longevity and cellular ROS production?

The present study was conducted to test predictions of the oxidative stress theory of aging assessing reactive oxygen species production and oxidative stress resistance in cultured fibroblasts from 13 primate species ranging in body size from 0.25 to 120 kg and in longevity from 20 to 90 years. We assessed both basal and stress-induced reactive oxygen species production in fibroblasts from five great apes (human, chimpanzee, bonobo, gorilla, and orangutan), four Old World monkeys (baboon, rhesus and crested black macaques, and patas monkey), three New World monkeys (common marmoset, red-bellied tamarin, and woolly monkey), and one lemur (ring-tailed lemur). Measurements of cellular MitoSox fluorescence, an indicator of mitochondrial superoxide (O2(·-)) generation, showed an inverse correlation between longevity and steady state or metabolic stress-induced mitochondrial O2(·-) production, but this correlation was lost when the effects of body mass were removed, and the data were analyzed using phylogenetically independent contrasts. Fibroblasts from longer-lived primate species also exhibited superior resistance to H(2)O(2)-induced apoptotic cell death than cells from shorter-living primates. After correction for body mass and lack of phylogenetic independence, this correlation, although still discernible, fell short of significance by regression analysis. Thus, increased longevity in this sample of primates is not causally associated with low cellular reactive oxygen species generation, but further studies are warranted to test the association between increased cellular resistance to oxidative stressor and primate longevity.

Calreticulin-dependent recycling in the early secretory pathway mediates optimal peptide loading of MHC class I molecules

Calreticulin is a lectin chaperone of the endoplasmic reticulum (ER). In calreticulin-deficient cells, major histocompatibility complex (MHC) class I molecules travel to the cell surface in association with a sub-optimal peptide load. Here, we show that calreticulin exits the ER to accumulate in the ER-Golgi intermediate compartment (ERGIC) and the cis-Golgi, together with sub-optimally loaded class I molecules. Calreticulin that lacks its C-terminal KDEL retrieval sequence assembles with the peptide-loading complex but neither retrieves sub-optimally loaded class I molecules from the cis-Golgi to the ER, nor supports optimal peptide loading. Our study, to the best of our knowledge, demonstrates for the first time a functional role of intracellular transport in the optimal loading of MHC class I molecules with antigenic peptide.

Evolutionarily conserved, cell type and species-specific higher order chromatin arrangements in interphase nuclei of primates

Several studies demonstrated a gene-density-correlated radial organization of chromosome territories (CTs) in spherically shaped nuclei of human lymphocytes or lymphoblastoid cells, while CT arrangements in flat-ellipsoidal nuclei of human fibroblasts are affected by both gene density and chromosome size. In the present study, we performed fluorescence in situ hybridization (FISH) experiments to three-dimensionally preserved nuclei (3D-FISH) from human and nonhuman primate cultured lymphoblastoid cells and fibroblasts. We investigated apes, Old, and New World monkeys showing either evolutionarily conserved karyotypes, multiple translocations, fusions, or serial fissions. Our goal was to test whether cell type specific differences of higher order chromatin arrangements are evolutionarily conserved in different primate lineages. Whole genome painting experiments and further detailed analyses of individual chromosomes indicate a gene-density-correlated higher order organization of chromatin in lymphoblastoid cell nuclei of all studied primate species, despite evolutionary chromosome reshuffling. In contrast, in primate fibroblast nuclei evolutionary translocations, fissions and fusions resulted in positional shifts of orthologous chromosome segments, thus arguing against a functional role of chromosome size-dependent spatial chromatin arrangements and for geometrical constraints in flat-ellipsoidal fibroblast nuclei. Notably, in both cell types, regions of rearranged chromosomes with distinct differences in gene density showed polarized arrangements with the more gene-dense segment oriented towards the nuclear interior. Our results indicate that nonrandom breakage and rejoining of preferentially gene-dense chromosomes or chromosome segments may have occurred during evolution.

Somatic gene transfer to the adult primate central nervous system: in vitroand in vivocharacterization of cells genetically modified to secrete nerve growth factor

Somatic gene transfer offers a means of delivering substances to the central nervous system (CNS) in a regionally specific, high-dose, chronic and well-tolerated manner. Studies in rats have shown that genetically modified cell grafts can prevent neuronal degeneration and promote functional recovery after injury and can improve cognitive function in aged subjects. To assess the potential utility of somatic gene transfer techniques in primate models, retroviral vectors were used to modify genetically monkey and human primary skin fibroblasts to produce and secrete human nerve growth factor (NGF). In vitro,all cell types produced NGF and sustained this production through cell growth to confluency, as determined by both Northern blot analysis and ELISA. Adult human fibroblasts produced as much NGF as did young human fibroblasts. Monkey fibroblasts genetically modified to produce NGF were then grafted to intact adult rhesus and cynomolgous monkey brains. Among nine primates that received a total of 76 grafts, surviving cells were found in all subjects up to the maximal experimental timepoint of 6 months. Cholinergic fibres from the host brain penetrated NGF-secreting grafts up to 6 months after grafting, but showed little penetration in control grafts lacking the NGF gene. Autografts survived better than allografts. These findings indicate that both human and primate fibroblasts can be transduced to produce and secrete NGF, can maintain this production whether in a growing or quiescent state and can elicit robust sprouting responses when primate fibroblasts are grafted to the adult brain. Cells genetically modified to produce trophic factors are a useful model for studying in vitroand in vivoCNS plasticity and for testing potential therapies for neurodegenerative conditions.

Infection of human cells with murine amphotropic replication-competent retroviruses.

Replication of the murine wild-type 4070A amphotropic retrovirus and a recombinant amphotropic replication-competent retrovirus arising from the PA12 packaging cell line varied considerably among the primate cell types tested. Medium from infected primate fibroblasts and endothelial cells contained the highest viral titers [10(4)-10(5) focus-forming units (ffu)/ml], while most hematopoietic cell lines, such as K562 and MOLT4, were associated with viral titers in the range of 10(3)-10(4) ffu/ml. Interestingly, HTLV-1-transformed T cell lines (TJF-2 and HM) and primary tumor infiltrating lymphocytes (TIL) had very low viral titer (0-10(1) ffu/ml). The low production of virus was not due to low infectivity and, in contrast to the virus, retroviral vectors were expressed without difficulty. Because screening for replication-competent retrovirus (RCR) is an important component of human retroviral-mediated gene therapy clinical protocols, a variety of assays were tested for their ability to detect RCR in virus-exposed cell lines. A biologic assay (3T3 amplification) and polymerase chain reaction (PCR) for the 4070A viral envelope are effective screening methods for RCR, even in cell lines associated with low virus production.

Differences in cell division and thymidine incorporation with rat and primate fibroblasts in collagen lattices

Human and gorilla dermal fibroblasts, primate cells, suspended in a collagen lattice, do not divide for the first 3 days. In contrast, rat fibroblasts divide within 24 hr. In this study, the proliferation of rat fibroblasts were compared to primate fibroblasts. Rat fibroblasts in monolayer culture increase from 100,000 to 355,000 in 2 days, and human cells increase from 100,000 to 436,000 in the same period. An initial seeding of 100,000 rat fibroblasts suspended in collagen increased to 163,000 cells in 2 days. An initial 100,000 human fibroblasts seeded in collagen decreased to 80,000 cells in 2 days. Retarded proliferation of human and gorilla fibroblasts in collagen is unrelated to a defect in DNA synthesis. By autoradiography human fibroblasts suspended in collagen incorporate labelled thymidine. By flow cytometry analysis, the DNA concentrations of human fibroblasts suspended in collagen exhibited 41% in a 4N chromosome state, compared to 14% in monolayer culture. Nuclei of gorilla fibroblasts from collagen displayed 42% in a 4N state, compared to 19% in monolayer culture. With nuclei of rat fibroblasts from collagen, 14% were in a 4N state, compared to 9% in monolayer culture. Primate fibroblasts show a three-fold increase in the number of nuclei in a 4N state compared to rat fibroblasts suspended in collagen. After replating fibroblasts released from collagen in monolayer culture in the presence of 1 mM hydroxyurea (an inhibitor of DNA synthesis) primate fibroblasts doubled in 24 hr. Under identical conditions, rat fibroblasts showed no cell division. Primate cells suspended in collagen have completed DNA synthesis but show a delay in cell division, indicating fibroblasts are arrested in G 2 of the cell cycle. Polymerized collagen produces a physical constraint on primate fibroblasts which retards these cells from entering mitosis. In contrast rat fibroblasts show no constraint and readily enter mitosis upon completion of DNA synthesis.

Comparison of proto oncogene expression in seven primate fibroblast cultures

In an interspecies comparison of seven primate species, the expression of the erbB proto oncogene was found to be higher in fibroblasts derived from three relatively longlived species, the human, gorilla, and chimpanzee than in cells from the orangutan, pygmy chimpanzee, squirrel monkey, or red-bellied tamarin. No significant difference was found in the expression of the ras-K, myc, or src proto oncogenes. The difference would not seem to be the result of age differences of the donor animals as we found little variation in the expression of the four proto oncogenes in human fibroblasts derived from donors ranging in age from newborn to 70 years old. In addition, we found little change in expression of the proto oncogenes during long term in vitro culturing, indicating that in vitro age of the individual cultures was not a significant factor in our results.

Isolation and characterization of monoclonal antibodies reactive with endothelial cells

Monoclonal antibodies were generated to antigens on cultured human umbilical vein endothelial cells. Spleen cells from BALB/c mice, immunized with low passage cultures of human umbilical vein endothelial cells, were fused with the non-secretory myeloma line, P3 × 63Ag 8.653. Hybridoma supernatants were screened for the desired immunological reactivity using ELISA binding assays. Hybridomas secreting antibodies reacting with the immunizing endothelial cells, but not with peripheral blood mononuclear cells, were cloned by limiting dilution and three stable clones were chosen for study. Further testing by ELISA revealed that each antibody displayed a unique pattern of reactivity. One antibody, 14E5, reacted with the macrophage-like cell line DHL-2, cultured macrophages derived from peripheral blood monocytes, and macrophages derived from malignant effusions. The antibody failed to react with fibroblasts or bovine endothelial cells. The second antibody, 12C6, reacted with human and primate fibroblasts and endothelial cells derived from bovine arteries, but not with mature macrophages. The third clone, 10B9, reacted only with the immunizing endothelial cells and the immature-macrophage line U-937. All three antibodies failed to react with long-term human B or T lymphoblastoid cell lines, leukemic cell lines, or murine macrophage lines. None of the antibodies reacted with a battery of human epithelial derived cell lines or primary cultures of human epithelial cells. Indirect immunofluorescence assays revealed that the antigens were expressed on the cell surface. These antibodies should prove useful as differentiation markers of human endothelial cells and in studies of endothelial cell function.

Antigenic relatedness of primate procollagens as determined by a competitive radioimmunoassay

1. 1. A radioimmunoassay specific for the nonhelical carboxy terminal portion of human type I procollagen was used to study the antigenic relatedness of primate procollagens. 2. 2. The assay identified reactive antigen in primate sera and in the media of primate fibroblast cultures. 3. 3. The displacement curves generated in the assay indicated that human and ape type I procollagens have antigenically identical carboxy terminal determinants which are partially cross-reactive with those from Old and New World Monkeys.

Concentrative accumulation (active transport) of 2-deoxy-D-glucose in primate fibroblasts

Incorporation of 2-deoxy-D-glucose into cultured rhesus diploid cells includes transport and subsequent phosphorylation with resultant accumulation of both free and phosphorylated sugar. Accumulation of the free sugar proceeds to a maximal limit of 4–5 mM which is determined by intrinsic cell factors and is independent of medium 2-deoxy-D-glucose up to 5 mM concentration. Concentrative accumulation (active transport) pf the free sugar is readily demonstrable on maintaining medium concentrations of 2-deoxy-D-glucose at less than the maximal accumulation potential of the cells (i.e. <4–5 mM). Cellular concentrations of the free sugar in excess of 30-times medium concentrations are demonstrable on incubation of the cells in the presence of <0.05 mM 2-deoxy-D-glucose. In contrast, accumulation of 2-deoxy-D-glycose is not demonstrable in the human erythrocyte.