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PubMed2003

[Adipose tissue-derived stromal cells differentiate into neuron-like cells].

OBJECTIVE: To investigate the possibility of inducing adipose tissue-derived stromal cells to differentiate into neuron-like cells, and to explore a new cell source for central nervous system transplantation. METHODS: beta-mercaptoethanol was adopted to induce the cells to differentiate; undifferentiated cells and differentiated cells were identified with immunocytochemistry. RESULTS: A population of adipose tissue-derived stromal cells were isolated from adult rat adipose tissue; they were processed to obtain a fibroblast-like population of cells and could be maintained in vitro for extended periods with stable population doubling, and they were expanded as undifferentiated cells in culture for more than 10 passages, indicating their proliferative capacity. beta-mercaptoethanol induced the stem cells to express nestin, characteristic of neuronal precursor stem cells at early stage of differentiation, and at late stage they exhibited a neuronal phenotype, expressing neuron-specific enolase (NSE) and neurofilament(NF); with an optimal differentiation protocol, almost 60%-85% of the cells expressed NSE and NF. CONCLUSION: The data support the hypothesis that adult adipose tissue contains stem cells capable of differentiating into neurons.

Adipose Tissue↗
PubMed2006

Adenovirally transduced bone marrow stromal cells differentiate into pigment epithelial cells and induce rescue effects in RCS rats.

PURPOSE: To determine the potential of adenovirally transduced bone marrow stromal cells (BMSCs) to differentiate into retinal pigment epithelial-like cells and to evaluabe possible rescue effects after transplantation into the retinas of Royal College of Surgeons (RCS) rats. METHODS: Through a high-capacity adenoviral vector expressing either green fluorescent protein (GFP) or pigment epithelial-derived factor (PEDF), rat MSCs were transduced in vitro before subretinal transplantation into Wistar rats or, alternatively, RCS rats. Two months after cell injection, the rats were killed and the eyes enucleated. The eyes were then investigated light microscopically or processed for electron microscopic investigations. Cell differentiation and integration were analyzed immunocytochemically using antibodies against cytokeratin and the tight junction protein ZO-1. Electroretinography was performed 16 days after injection of cells, to check whether a functional rescue could be detected. RESULTS: In vitro experiments in cocultured human MSCs and human RPE cells showed that MSCs adopted RPE-like characteristics. In grafting experiments, some rat MSCs integrate into the host RPE cell layer of Wistar and RCS rats, indicated by their hexagonal morphology. Subretinally transplanted cells express the epithelial marker cytokeratin and establish tight junctions with the host RPE cells. Furthermore, rescue effects can be demonstrated after grafting of vector-transduced and nontransduced MSCs in semithin sections of dystrophic retinas. Ultrastructurally, MSCs can be detected on top of host RPE and in close contact with photoreceptor outer segments phagocytosing rod outer segments. CONCLUSIONS: Taken together, these results raise the possibility that MSCs have the potency to replace diseased RPE cells and deliver therapeutic proteins into the subretinal space to protect photoreceptor cells from degeneration.

Adenoviridae↗
PubMed1996

Schwann cell differentiation of modified myoepithelial cells within adenoid cystic carcinomas and polymorphous low-grade adenocarcinomas: clinicopathologic assessment of immunohistochemical staining.

Adenoid cystic carcinomas and polymorphous low-grade adenocarcinomas have a known propensity for perineural invasion. Although modified myoepithelial cells have been shown to possess characteristics of a variety of cell types, they have not yet been found to mimic nerve tissue. Histologic evidence of Schwann cell differentiation would suggest the pathophysiologic mechanism by which these tumours exhibit neurotropism. An archival study of 41 specimens was performed to evaluate the Schwann cell staining properties of adenoid cystic and polymorphous low-grade adenocarcinomas using antibodies to S-100 protein, GFAP, neuron-specific enolase, and using a solochrome stain. Charts were reviewed to assess correlations between immunohistochemical and histochemical staining properties and various clinical parameters. The findings strongly suggest that neuronal differentiation does occur within these tumours. Furthermore, it was determined that solochrome positivity confers a significantly less favourable disease-free interval in these neoplasms. This new finding was highly statistically significant and has potential implications in the determination of prognosis for patients with these tumours.

Adenocarcinoma↗
PubMedDate not supplied

The hormones--a model for a new understanding of cell differentiation process. Part I. Differentiation--an individual cell option?

From the beginning I want to explain some interesting notions about cytodifferentiation, these being seen, in my view, like an Instructive Informatory Theory. Then, I tried to present the sustaining arguments for an extracellular differentiation. These arguments reveal that final decision in differentiation process are the receptor molecules. Therefore, I present some actual questions arisen about the correlations between receptors and secondary messengers. The hormones action models are the single way to clear up the vagueness about the nucleus-receptor connection.

Animals↗
PubMed1990

Effects of antineoplastic phospholipids on parameters of cell differentiation in U937 cells.

The proliferation of the human promonocytic leukemia cell line U937 is inhibited by several ether lipids, ether lipid analogues and by phorbol esters. An early effect of this retardation of cell growth is the induction of a basic chromosomal protein, histone H1(0). Northern blot analysis of H1(0) mRNA levels reveals an increase of the mRNA concentration within a few hours after addition of hexadecylphosphocholine and 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine. This early effect on the synthesis of a subtype of H1 proteins precedes the expression of several parameters of the monocytic differentiation of U937 cells.

Antigens, Surface↗
PubMed2006

Epigenetic regulation of stem cell differentiation.

Stem cells undergo extensive self-renewal and have the capacity to differentiate along multiple cell lineages. Progression from stem cells into differentiated progeny requires long-lasting changes in gene expression. Epigenetic mechanisms, including DNA methylation, histone modifications, and non-coding RNA-mediated regulatory events, are essential to controlling the heritable cellular memory of gene expression during development. Recent studies on cell fate specification of embryonic and adult stem cells/progenitors have highlighted a general and critical role for dynamic epigenetic regulation in stem cell self-renewal and differentiation.

Adult↗
PubMed1998

Surrogate light chain production during B cell differentiation: differential intracellular versus cell surface expression.

Expression of the surrogate light (psi L) chain genes encoding the VpreB and lambda 5/14.1 proteins is restricted to B-lineage cells. Pro-B and pre-B cells produce psi L chains, but whether both employ these as cell surface receptor components remains enigmatic. Recombinant human VpreB protein was used to generate a large panel of monoclonal anti-VpreB Abs to examine this issue. Native psi L chain proteins within pro-B cells as well as those serving as receptor components on pre-B cells were precipitated by 16 of the 26 anti-VpreB Abs. Surrogate light chains were easily detected on pre-B cell lines, whereas these anti-VpreB Abs reacted with pro-B cell lines only after plasma membrane permeabilization. The subpopulation of normal bone marrow cells bearing pre-B receptors included large and small pre-B cells exclusively, although pro-B cells also contained intracellular VpreB. VpreB proteins were not detected on or within B cells in bone marrow or the circulation, but a subpopulation of B cells in germinal centers was found to express the VpreB proteins intracellularly. Surrogate L chains are thus intermittently produced during human B-lineage differentiation, while their role as receptor components appears limited to the pre-B cell stage.

Antibodies, Monoclonal↗
PubMed1989

Sequential expression of smooth muscle and sarcomeric alpha-actin isoforms during BC3H1 cell differentiation.

High cell density and cell cycle withdrawal stimulate the differentiation of BC3H1 smooth muscle-like cells. The differentiation process is accompanied by extensive changes in cell shape and the increased expression of a variety of muscle-specific proteins including the vascular smooth muscle-specific isoform of the contractile protein, alpha-actin. Results of actin peptide map analyses described in this report now indicate that a second, sarcomeric muscle-specific alpha-actin isoform is expressed in serum-deprived BC3H1 myocytes and that the induction of this actin isoform occurs late in differentiation well after the observed upregulation of vascular alpha-actin synthesis. The sarcomeric alpha-actin was identified in myocytes on the basis of the unique electrophoretic mobility of its NH2-terminal tryptic peptide, the distribution of cleavage products that were obtained when the NH2-terminal tryptic peptide was subjected to secondary proteolytic cleavage with thermolysin and Staphylococcus aureus V8 protease, and the presence of an additional cysteine residue at the NH2 terminus of the biosynthetic precursor of this novel alpha-actin. While expression of vascular alpha-actin was stimulated when myoblasts reached confluence, a 6-day post-confluent treatment with serum-free medium was required to induce maximal expression of the sarcomeric alpha-actin. Blot hybridization analysis of total BC3H1 myocyte RNA using actin gene-specific cDNA probes indicated that the sarcomeric alpha-actin corresponds to the skeletal muscle-specific isoform. This is the first report describing dual expression of smooth muscle and sarcomeric muscle alpha-actins in a clonal myogenic cell line. The results indicate the potential usefulness of the BC3H1 cell line for studying relationships between divergent muscle alpha-actin gene sequences and transcriptional and translational controls during myogenesis.

Actins↗
PubMed2003

2-arachidonoylglycerol induces the migration of HL-60 cells differentiated into macrophage-like cells and human peripheral blood monocytes through the cannabinoid CB2 receptor-dependent mechanism.

2-Arachidonoylglycerol is an endogenous ligand for the cannabinoid receptors (CB1 and CB2) and has been shown to exhibit a variety of cannabimimetic activities in vitro and in vivo. Recently, we proposed that 2-arachidonoylglycerol is the true endogenous ligand for the cannabinoid receptors, and both receptors (CB1 and CB2) are primarily 2-arachidonoylglycerol receptors. The CB1 receptor is assumed to be involved in the attenuation of neurotransmission. On the other hand, the physiological roles of the CB2 receptor, which is abundantly expressed in several types of leukocytes such as macrophages, still remain unknown. In this study, we examined the effects of 2-arachidonoylglycerol on the motility of HL-60 cells differentiated into macrophage-like cells. We found that 2-arachidonoylglycerol induces the migration of differentiated HL-60 cells. The migration induced by 2-arachidonoylglycerol was blocked by treatment of the cells with either SR144528, a CB2 receptor antagonist, or pertussis toxin, suggesting that the CB2 receptor and Gi/Go are involved in the 2-arachidonoylglycerol-induced migration. Several intracellular signaling molecules such as Rho kinase and mitogen-activated protein kinases were also suggested to be involved. In contrast to 2-arachidonoylglycerol, anandamide, another endogenous cannabinoid receptor ligand, failed to induce the migration. The 2-arachidonoylglycerol-induced migration was also observed for two other types of macrophage-like cells, the U937 cells and THP-1 cells, as well as human peripheral blood monocytes. These results strongly suggest that 2-arachidonoylglycerol induces the migration of several types of leukocytes such as macrophages/monocytes through a CB2 receptor-dependent mechanism thereby stimulating inflammatory reactions and immune responses.

Adjuvants, Immunologic↗
PubMed2006

Effector T cell differentiation and memory T cell maintenance outside secondary lymphoid organs.

Naive T cell circulation is restricted to secondary lymphoid organs. Effector and memory T cells, in contrast, acquire the ability to migrate to nonlymphoid tissues. In this study we examined whether nonlymphoid tissues contribute to the differentiation of effector T cells to memory cells and the long-term maintenance of memory T cells. We found that CD4, but not CD8, effector T cell differentiation to memory cells is impaired in adoptive hosts that lack secondary lymphoid organs. In contrast, established CD4 and CD8 memory T cells underwent basal homeostatic proliferation in the liver, lungs, and bone marrow, were maintained long-term, and functioned in the absence of secondary lymphoid organs. CD8 memory T cells found in nonlymphoid tissues expressed both central and effector memory phenotypes, whereas CD4 memory T cells displayed predominantly an effector memory phenotype. These findings indicate that secondary lymphoid organs are not necessary for the maintenance and function of memory T cell populations, whereas the optimal differentiation of CD4 effectors to memory T cells is dependent on these organs. The ability of memory T cells to persist and respond to foreign Ag independently of secondary lymphoid tissues supports the existence of nonlymphoid memory T cell pools that provide essential immune surveillance in the periphery.

Animals↗
PubMed2003

Tissue engineering of blood vessels with endothelial cells differentiated from mouse embryonic stem cells.

Endothelial cells (TEC3 cells) derived from mouse embryonic stem (ES) cells were used as seed cells to construct blood vessels. Tissue engineered blood vessels were made by seeding 8 106 smooth muscle cells (SMCs) obtained from rabbit arteries onto a sheet of nonwoven polyglycolic acid (PGA) fibers, which was used as a biodegradable polymer scaffold. After being cultured in DMEM medium for 7 days in vitro, SMCs grew well on the PGA fibers, and the cell-PGA sheet was then wrapped around a silicon tube, and implanted subcutaneously into nude mice. After 6~8 weeks, the silicon tube was replaced with another silicon tube in smaller diameter, and then the TEC3 cells (endothelial cells differentiated from mouse ES cells) were injected inside the engineered vessel tube as the test group. In the control group only culture medium was injected. Five days later, the engineered vessels were harvested for gross observation, histological and immunohistochemical analysis. The preliminary results demonstrated that the SMC-PGA construct could form a tubular structure in 6~8 weeks and PGA fibers were completely degraded. Histological and immunohistochemical analysis of the newly formed tissue revealed a typical blood vessel structure, including a lining of endothelial cells (ECs) on the lumimal surface and the presence of SMC and collagen in the wall. No EC lining was found in the tubes of control group. Therefore, the ECs differentiated from mouse ES cells can serve as seed cells for endothelium lining in tissue engineered blood vessels.

Animals↗
PubMed1999

Dendritic cell differentiation pathways of CD34+ cells from the peripheral blood of head and neck cancer patients.

Patients with head and neck squamous cell carcinoma (HNSCC) have increased levels of immune-suppressive peripheral blood CD34+ cells. This study showed that the peripheral blood CD34+ cells of HNSCC patients are capable of differentiating into dendritic cells. Because CD34+ cells can differentiate through several pathways into dendritic cell subpopulations, the intermediate cells through which the blood CD34+ cells of HNSCC patients differentiate were identified. After 6-7 days of culturing the CD34+ cells of HNSCC patients with granulocyte-macrophage colony-stimulating factor, stem cell factor, and tumor necrosis factor at, there appeared CD14+CD1a+ and a lesser proportion of CD14(-)CD1a+ cells resembling the precursor cells of the bipotential and committed dendritic cell differentiation pathways that have been described for cord blood CD34+ cells. To functionally analyze whether these populations were in fact precursor cells, they were isolated and cultured for an additional 10-12 days. Each of these populations was shown to function as precursor cells because they were able to develop into cells that resembled dendritic cells, although a higher proportion developed from the CD14-CD1a+ cells. In contrast, expression of the dendritic activation/maturation marker CD83 was highest on the cells that developed from CD14+CD1a+ cells. Thus, the CD34+ cells whose levels are increased in HNSCC patients can develop into both committed and bipotential dendritic precursor cells, which can subsequently give rise to dendritic cells.

Antigens, CD1↗
PubMed1999

Production of matrix-degrading enzymes and inhibition of osteoclast-like cell differentiation by fibroblast-like cells from the periodontal ligament of human primary teeth.

Clinically, the most apparent difference between the primary and permanent dentitions is the physiologic loss of the primary tooth by root resorption. Root resorption is associated with loss of integrity of the periodontal ligament (PDL), followed by recruitment of resorptive cells that remove root structure. We therefore cultured primary dentition PDL fibroblasts (PPDL cells) to investigate in vitro their production of matrix metalloproteinases (MMPs) and tissue inhibitors of MMP (TIMPs), and the effects of soluble factors produced by these cells on osteoclast-like cell differentiation. These studies demonstrate that PPDL cells in vitro have a heterogeneous morphology, and they constitutively synthesize 92-kDa gelatinase, 72-kDa gelatinase, and 53/57-kDa procollagenase as well as TIMP-1, -2, and a third inhibitor of matrix metalloproteinase, as determined by substrate gel zymography and immunoblot analysis. Compared with PDL cells from the permanent dentition, PPDL cells generally produced a greater amount of collagenase but similar amounts of the gelatinases and inhibitors. PPDL cells were treated with pro-inflammatory cytokines to determine their effect on the expression of matrix-degrading enzymes and inhibitors. Interleukin-1alpha and tumor necrosis factor-alpha enhanced the constitutive expression of proteinases but not that of inhibitors in PPDL cells. Conditioned media from PPDL cell lines inhibited the differentiation of osteoclast-like cells in mouse bone marrow cultures. These findings indicate that PPDL cells may modulate the cascade of root resorption both by their regulated production of proteinases and inhibitors and by synthesis of unknown soluble factor(s) that may regulate osteoclast development.

Adult↗
PubMed1991

Analyses of T-cell differentiation from hemopoietic stem cells in the G0 phase by an in vitro method.

Using differential radiation sensitivity of components of mouse embryonal thymus, an in vitro method for studying T-cell differentiation from hemopoietic stem cells (HSCs) in the G0 phase was established. Intrathymic T-cell precursors present in embryonal thymus were found to be quite radioresistant (up to 20 Gy), and consequently 25-Gy-irradiated embryonal thymic lobes were used. Thymic lobes (25-Gy irradiated) taken from mouse fetuses (gestation day 15) were placed in Millipore-HA culture plates supported on squares of gelatin foam sponge in 24-well culture plates in which neonatal thymus stromal cells were cultured. HSCs (10(5) cells per well) in the G0 phase were added to these thymic lobes and cocultured at 37 degrees C in a 5% CO2/95% air incubator. Half the culture medium was changed every week. After 3 weeks, a large number of colonies had formed. Immunohistochemical studies and fluorescence-activated cell sorter analyses revealed that the colonizing cells regularly develop and exhibit surface markers characteristic of T cells (Thy-1, IL-2R, L3T4, Lyt-2, etc.). In situ hybridization analyses revealed that mRNA expression for T-cell receptor (TCR) beta chains occurred within colonizing cells. Using a monoclonal antibody (F23.1), expression of TCR beta-chain variable domain (V beta 8) on the surface of these developing T cells was demonstrated. These cells responded to interleukin 2 and/or anti-CD3 monoclonal antibody, indicating functional T cells. This method will be useful in studying T-cell differentiation pathways from pluripotent HSCs and in clarifying the mechanisms involved in negative and positive selection of T cells within the thymus.

Animals↗
PubMed2004

D609 induces vascular endothelial cells and marrow stromal cells differentiation into neuron-like cells.

AIM: To investigate the effect of tricyclodecane-9-yl-xanthogenate (D609) on cell differentiation in vascular endothelial cells (VECs) and marrow stromal cells (MSCs). METHODS: Morphological changes were observed under phase contrast microscope. Electron microscope and immunostaining were used for VECs identification. The expressions of neuron-specific enolase (NSE) and glial fibrillary acidic protein (GFAP) were examined by immunohistochemistry. RESULTS: After 6 h of induction with D609, some VECs showed morphological changes characteristic of neurones. 9 h later, more VECs became neuron-like cells. About 30.8% of VECs displayed positive NSE (P<0.01), while the expression of GFAP was negative. When MSCs were exposed to D609, the cells displayed neuronal morphologies, such as pyramidal cell bodies and processes formed extensive networks at 3 h. 6 h later, almost all of the cells exhibited a typical neuronal appearance, and 85.6% of MSCs displayed intensive positive NSE, but GFAP did not express. CONCLUSION: D609 induces VECs and MSCs differentiation into neuron-like cells.

Antioxidants↗
PubMed2005

Promotion of cell differentiation, and suppression of cell growth and cyclooxygenase-2 expression by differentiation-inducing agents in human oral squamous carcinoma SCC25 cells.

We investigated the relationship between cell growth and differentiation and COX-2 expression in oral squamous cell carcinoma (SCC) in vitro and in vivo. Treatment of SCC25 oral squamous carcinoma cells with sodium butyrate (SB) at 0.5-5 mM or all-trans retinoic acid (ATRA) at 3-300 microM inhibited cell growth and induced apoptosis in a dose-dependent manner with concomittant increases in expression of keratin 13, p21WAF1/Cip1 and p27Kip1 and decreases in expression of COX-2. These effects were more pronounced with SB than with ATRA. Injection of SB or ATRA near SCC25-derived tumors in nude mice resulted in inhibition of growth and elevation of differentiation of the tumor accompanied by marked keratinization and increased expression of keratin 13 and decreased expression of COX-2. These results show that the differentiation-inducing agents, particularly SB, suppress growth of oral squamous carcinoma cells through apoptosis and induce cell differentiation possibly through mechanisms involving COX-2, p27Kip1 and/or p21WAF1/Cip1 in vitro and in vivo.

Animals↗
PubMed1998

Changes in glycosaminoglycan structure and composition of the main heparan sulphate proteoglycan from human colon carcinoma cells (perlecan) during cell differentiation.

Colon carcinoma cells provide a useful model to study the biochemical processes associated with cell differentiation. Undifferentiated HT29, differentiated HT29MTX(-3) and HT29MTX(-6), and Caco2 human colon carcinoma cells have been used to study the production of proteoglycans and to characterize the glycosaminoglycan structure of the heparan sulphate chains. All the cell lines produce mainly a heparan sulphate proteoglycan that is found partly in the extracellular medium and associated to the cell membrane. The heparan sulphate proteoglycans from the media were purified by ion-exchange chromatography and subjected to structural analysis. The heparan sulphate proteoglycan from differentiated cells is larger and more homogeneous in size than the heparan sulphate proteoglycan from undifferentiated HT29 cells. No differences in protein core structure were observed when cells were labeled with [35S]methionine and the protein cores visualized by gel electrophoresis. Nevertheless, differences in glycosaminoglycan composition were found correlated with the degree of differentiation. The heparan sulphate chains from differentiated HT29MTX(-3) and HT29MTX(-6) cells have a higher sulphation degree than those from undifferentiated HT29 cells. The heparan sulphate from Caco2 cells is the most highly sulphated species. The differences are mainly attributed to O-sulphate groups. The increase in O-sulphation was more pronounced for D-glucosamine 6-O-sulphate than for L-iduronic acid 2-O-sulphate groups.

Carbohydrate Sequence↗
PubMed1999

Lens fibre cell differentiation - A link with apoptosis?

During the process of terminal differentiation, the fibre cells in the eye lens undergo many changes that are reminiscent of apoptotic/necrotic changes. Mitochondria, for instance, undergo permeability transition and nuclear degradation is accompanied by chromatin condensation, disintegration of the nucleolus, dissolution of the nuclear lamina, nuclear pore clustering and fragmentation of the DNA into oligonucleosomal fragments. As during apoptosis, members of the caspase family of proteases were shown to be active during fibre cell differentiation and Bcl-2 overexpression was demonstrated to block normal differentiation of lens cells. In this review, the current knowledge of the sequence of events during cell death is summarised and contrasted with events during lens fibre cell differentiation. Due to the numerous similarities between these processes, lens fibre cell differentiation is suggested to represent an attenuated form of cell death.

Animals↗