Epithelial Cells

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David A. Sullivan - One of the best experts on this subject based on the ideXlab platform.

  • serum induced differentiation of human meibomian gland Epithelial Cells
    Investigative Ophthalmology & Visual Science, 2014
    Co-Authors: David A. Sullivan, Juan Ding, Karin M Green, Scott A Shaffer, Mark P Hatton
    Abstract:

    Purpose. We hypothesize that culturing immortalized human meibomian gland Epithelial Cells in serum-containing medium will induce their differentiation. The purpose of this investigation was to begin to test our hypothesis, and explore the impact of serum on gene expression and lipid accumulation in human meibomian gland Epithelial Cells.

  • effect of growth factors on the proliferation and gene expression of human meibomian gland Epithelial Cells
    Investigative Ophthalmology & Visual Science, 2013
    Co-Authors: Juan Ding, Mark P Hatton, David A. Sullivan
    Abstract:

    PURPOSE. We hypothesize that growth factors, including epidermal growth factor (EGF) and bovine pituitary extract (BPE), induce proliferation, but not differentiation (e.g., lipid accumulation), of human meibomian gland Epithelial Cells. We also hypothesize that these actions involve a significant upregulation of genes linked to cell cycle processes, and a significant downregulation of genes associated with differentiation. Our objective was to test these hypotheses. METHODS. Immortalized human meibomian gland and conjunctival Epithelial Cells were cultured for varying time periods in the presence or absence of EGF, BPE, EGF þ BPE, or serum, followed by cell counting, neutral lipid staining, or RNA isolation for molecular biological procedures. RESULTS. Our studies show that growth factors stimulate a significant, time-dependent proliferation of human meibomian gland Epithelial Cells. These effects are associated with a significant upregulation of genes linked to cell cycle, DNA replication, ribosomes, and translation, and a significant decrease in those related to cell differentiation, tissue development, lipid metabolic processes, and peroxisome proliferator-activated receptor signaling. Serum-induced differentiation, but not growth factor-related proliferation, elicits a pronounced lipid accumulation in human meibomian gland Epithelial Cells. This lipogenic response is unique, and is not duplicated by human conjunctival Epithelial Cells. CONCLUSIONS. Our results demonstrate that EGF and BPE stimulate human meibomian gland Epithelial Cells to proliferate. Further, our findings show that action is associated with an upregulation of cell cycle and translation ontologies, and a downregulation of genetic pathways linked to differentiation and lipid biosynthesis.

  • androgen regulation of gene expression in human meibomian gland and conjunctival Epithelial Cells
    Molecular Vision, 2012
    Co-Authors: Payal Khandelwal, David A. Sullivan
    Abstract:

    Purpose: Androgens exert a significant influence on the structure, function and/or pathophysiology of the meibomian gland and conjunctiva. We sought to determine whether this hormone action involves the regulation of Epithelial cell gene expression in these tissues. Methods: Immortalized human meibomian gland and conjunctival Epithelial Cells were treated with placebo or dihydrotestosterone (DHT) and processed for molecular biologic procedures. Gene expression was evaluated with BeadChips and data were analyzed with bioinformatic and statistical software. Results: Androgen treatment significantly influenced the expression of approximately 3,000 genes in immortalized human meibomian gland and conjunctival Epithelial Cells. The nature of DHT action on gene activity was predominantly Cellspecific. Similarly, DHT exerted a significant, but primarily cell-specific, influence on many gene ontologies and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. These included groups of genes related, for example, to lipid dynamics, innate immunity, cell cycle, Janus kinase (JAK)-signal transducer and activator of transcription (stat) cascades, oxidative phosphorylation, the proteasome, and mammalian target of rapamycin (mTOR), Wnt, and peroxisome proliferator-activated receptor (PPAR) signaling. Conclusions: Our findings support our hypothesis that androgens regulate gene expression in human meibomian gland and conjunctival Epithelial Cells. Our ongoing studies are designed to determine whether many of these genes are translated and play a role in the health and well being of the eye.

  • culture immortalization and characterization of human meibomian gland Epithelial Cells
    Investigative Ophthalmology & Visual Science, 2010
    Co-Authors: Mark P Hatton, Payal Khandelwal, David A. Sullivan
    Abstract:

    Meibomian glands are essential in maintaining the health and integrity of the ocular surface.1–6 These glands actively synthesize lipids and secrete them at the upper and lower eyelid margins just anterior to the mucocutaneous junctions. These glandular lipids then spread onto the tear film and promote the stability and prevent the evaporation of this film.1–6 Meibomian gland lipids may also help preserve visual acuity, provide lubrication during blinking, interfere with bacterial colonization, and prevent tear overflow.1–6 Meibomian gland dysfunction (MGD), in turn, leads to tear film instability and evaporation1–6 and is thought to be the major cause of dry eye syndrome throughout the world.7 However, aside from its regulation by sex steroids8–13 or the negative impact of retinoic acid,14 almost nothing is known about the physiological control of the meibomian gland in health or disease. This dearth of knowledge is somewhat surprising, given that the meibomian gland is a large sebaceous gland, and numerous articles have been published about the neural, hormonal, and secretagogue modulation of nonocular sebaceous gland tissue.15–24 These reports have shown that the nature of sebaceous gland regulation may vary significantly depending on the type of gland and its skin location. And of particular importance, much of this knowledge of sebaceous gland control has been generated by research with primary, and especially, immortalized sebaceous gland Epithelial Cells.25–28 We seek to advance our understanding of the regulation of meibomian gland function and the mechanisms underlying MGD. We also seek to translate this knowledge into the development of novel and unique therapeutic strategies to treat MGD and evaporative dry eye. Toward that end, we had a twofold purpose in this study: first, to establish a defined culture system for the maintenance of primary Epithelial Cells from human meibomian glands and, second, to immortalize these meibomian gland Epithelial Cells, thereby developing cell cultures that could be useful for identifying factors that regulate meibomian gland Epithelial cell activity.

Roy L Silverstein - One of the best experts on this subject based on the ideXlab platform.

  • cd36 expression in sltered in retinal pigment Epithelial Cells of the rcs rat
    Experimental Eye Research, 1997
    Co-Authors: Janet R Sparrow, Sandra W Ryeom, Nada A Abumrad, Azeddine Ibrahimi, Roy L Silverstein
    Abstract:

    Abstract The retinal pigment Epithelial cell has several important functions, one of which is the phagocytosis of photoreceptor outer segments which are discarded diurnally. We previously provided evidence in human retinal pigment epithelium that CD36, an 88 kDa integral membrane glycoprotein, participates in the phagocytosis of photoreceptor outer segments. Since in the Royal College of Surgeons dystrophic rat, retinal pigment Epithelial Cells fail to perform this function and as a result the photoreceptor Cells degenerate, the expression of CD36 has now been examined by retinal pigment Epithelial Cells of the dystrophic rat. Consistent with earlier work using human retinal pigment Epithelial Cells, expression of CD36 by freshly isolated retinal pigment Epithelial Cells of Long Evans rats was confirmed by immunoblotting and immunocytochemistry with antibody to rat CD36. The protein was also present in lysates of cultured retinal pigment epithelium. Furthermore, with an in vitro phagocytosis assay using 125 I-labeled outer segments, it was demonstrated that the binding and ingestion of outer segments by rat retinal pigment Epithelial Cells was reduced by 64% in the presence of antibodies to rat CD36. In contrast to observations in the Long Evans rat, immunoblotting of retinal pigment Epithelial Cells isolated from the adult Royal College of Surgeons rat revealed that CD36 protein was not present. This appeared to be a tissue-specific absence since CD36 protein was present in peritoneal macrophages harvested from the adult Royal College of Surgeons rat. A developmental study of CD36 expression also demonstrated an absence of the protein on the day of birth and at 1 and 2 weeks postnatally. By reverse transcriptase-polymerase chain reaction, CD36 mRNA was detected in freshly harvested retinal pigment Epithelial Cells of the Royal College of Surgeons rat at only PN1, 1 week and 10 days. Significantly, at 2 weeks of age and in the adult Royal College of Surgeons rat, CD36 transcripts were no longer present. Nevertheless, by Northern blot analysis CD36 mRNA was detected in various other tissues shown previously to express CD36. We conclude that in RPE Cells of the Royal College of Surgeons rat, CD36 protein is not expressed while CD36 mRNA is present only transiently during postnatal development.

Walter Birchmeier - One of the best experts on this subject based on the ideXlab platform.

  • hepatocyte growth factor scatter factor induces a variety of tissue specific morphogenic programs in Epithelial Cells
    Journal of Cell Biology, 1995
    Co-Authors: Volker Brinkmann, Martin Sachs, K M Weidner, Hosein Foroutan, Walter Birchmeier
    Abstract:

    Hepatocyte growth factor/scatter factor (HGF/SF) is the mesenchymal ligand of the Epithelial tyrosine kinase receptor c-Met. In vitro, HGF/SF has morphogenic properties, e.g., induces kidney Epithelial Cells to form branching ducts in collagen gels. Mutation of the HGF/SF gene in mice results in embryonic lethality due to severe liver and placenta defects. Here, we have evaluated the morphogenic activity of HGF/SF with a large variety of Epithelial Cells grown in three-dimensional collagen matrices. We found that HGF/SF induces SW 1222 colon carcinoma Cells to form crypt-like structures. In these organoids, Cells exhibit apical/basolateral polarity and build a well-developed brush border towards the lumen. Capan 2 pancreas carcinoma Cells, upon addition of HGF/SF, develop large hollow spheroids lined with a tight layer of polarized Cells. Collagen inside the cysts is digested and the Cells show features of pancreatic ducts. HGF/SF induces EpH4 mammary Epithelial Cells to form long branches with end-buds that resemble developing mammary ducts. pRNS-1-1 prostate Epithelial Cells in the presence of HGF/SF develop long ducts with distal branching as found in the prostate. Finally, HGF/SF simulates alveolar differentiation in LX-1 lung carcinoma Cells. Expression of transfected HGF/SF cDNA in LX-1 lung carcinoma and EpH4 mammary Epithelial Cells induce morphogenesis in an autocrine manner. In the cell lines tested, HGF/SF activated the Met receptor by phosphorylation of tyrosine residues. These data show that HGF/SF induces intrinsic, tissue-specific morphogenic activities in a wide variety of Epithelial Cells. Apparently, HGF/SF triggers respective endogenous programs and is thus an inductive, not an instructive, mesenchymal effector for Epithelial morphogenesis.

  • scatter factor molecular characteristics and effect on the invasiveness of Epithelial Cells
    Journal of Cell Biology, 1990
    Co-Authors: K M Weidner, Jan Vandekerckhove, Jürgen Behrens, Walter Birchmeier
    Abstract:

    The generation of invasiveness in transformed Cells represents an essential step of tumor progression. We have previously shown that MDCK Epithelial Cells, which are deprived of intracellular adhesion by the addition of anti-Arc-1/uvomorulin antibodies, become invasive for collagen gels and embryonal heart tissue (Behrens, J., M. M. Mareel, F. M. Van Roy, and W. Birchmeier. 1989. J. Cell Biol. 108: 2435-2447.). Here we examined whether invasiveness is also induced by scatter factor, which is known to dissociate Epithelial Cells (Stoker, M., E. Gherardi, M. Perryman, and J. Gray. 1987. Nature (Lond.). 327:239-242.). Scatter factor was purified to homogeneity from conditioned medium of human fibroblasts by heparin-Sepharose chromatography, followed by cation exchange chromatography, gel filtration, or preparative SDS gel electrophoresis. We found that scatter factor represents a 92,000 mol wt glycoprotein which, apparently, is converted by limited proteolysis into disulfide-linked 62,000 and 34/32,000 mol wt subunits. Reversed phase HPLC and sequence analysis of tryptic peptides confirmed the suggested molecular structure, and revealed further that scatter factor exhibits sequence similarities to hepatocyte growth factor and to plasminogen. Purified scatter factor in fact induces the invasiveness into collagen matrices of MDCK Epithelial Cells, and induces or promotes the invasiveness of a number of human carcinoma cell lines. Apparently, the effect on the human Cells depends on their respective degree of differentiation, i.e., cell lines with a less pronounced Epithelial phenotype were more susceptible to the factor. Scatter factor does not seem to influence synthesis, steady-state level, and phosphorylation of the cell adhesion molecule Arc-1/uvomorulin. Thus, scatter factor represents a clearly defined molecular species which induces, in vitro, the progression of Epithelial Cells to a more motile, i.e., invasive phenotype.

Mark P Hatton - One of the best experts on this subject based on the ideXlab platform.

  • serum induced differentiation of human meibomian gland Epithelial Cells
    Investigative Ophthalmology & Visual Science, 2014
    Co-Authors: David A. Sullivan, Juan Ding, Karin M Green, Scott A Shaffer, Mark P Hatton
    Abstract:

    Purpose. We hypothesize that culturing immortalized human meibomian gland Epithelial Cells in serum-containing medium will induce their differentiation. The purpose of this investigation was to begin to test our hypothesis, and explore the impact of serum on gene expression and lipid accumulation in human meibomian gland Epithelial Cells.

  • effect of growth factors on the proliferation and gene expression of human meibomian gland Epithelial Cells
    Investigative Ophthalmology & Visual Science, 2013
    Co-Authors: Juan Ding, Mark P Hatton, David A. Sullivan
    Abstract:

    PURPOSE. We hypothesize that growth factors, including epidermal growth factor (EGF) and bovine pituitary extract (BPE), induce proliferation, but not differentiation (e.g., lipid accumulation), of human meibomian gland Epithelial Cells. We also hypothesize that these actions involve a significant upregulation of genes linked to cell cycle processes, and a significant downregulation of genes associated with differentiation. Our objective was to test these hypotheses. METHODS. Immortalized human meibomian gland and conjunctival Epithelial Cells were cultured for varying time periods in the presence or absence of EGF, BPE, EGF þ BPE, or serum, followed by cell counting, neutral lipid staining, or RNA isolation for molecular biological procedures. RESULTS. Our studies show that growth factors stimulate a significant, time-dependent proliferation of human meibomian gland Epithelial Cells. These effects are associated with a significant upregulation of genes linked to cell cycle, DNA replication, ribosomes, and translation, and a significant decrease in those related to cell differentiation, tissue development, lipid metabolic processes, and peroxisome proliferator-activated receptor signaling. Serum-induced differentiation, but not growth factor-related proliferation, elicits a pronounced lipid accumulation in human meibomian gland Epithelial Cells. This lipogenic response is unique, and is not duplicated by human conjunctival Epithelial Cells. CONCLUSIONS. Our results demonstrate that EGF and BPE stimulate human meibomian gland Epithelial Cells to proliferate. Further, our findings show that action is associated with an upregulation of cell cycle and translation ontologies, and a downregulation of genetic pathways linked to differentiation and lipid biosynthesis.

  • culture immortalization and characterization of human meibomian gland Epithelial Cells
    Investigative Ophthalmology & Visual Science, 2010
    Co-Authors: Mark P Hatton, Payal Khandelwal, David A. Sullivan
    Abstract:

    Meibomian glands are essential in maintaining the health and integrity of the ocular surface.1–6 These glands actively synthesize lipids and secrete them at the upper and lower eyelid margins just anterior to the mucocutaneous junctions. These glandular lipids then spread onto the tear film and promote the stability and prevent the evaporation of this film.1–6 Meibomian gland lipids may also help preserve visual acuity, provide lubrication during blinking, interfere with bacterial colonization, and prevent tear overflow.1–6 Meibomian gland dysfunction (MGD), in turn, leads to tear film instability and evaporation1–6 and is thought to be the major cause of dry eye syndrome throughout the world.7 However, aside from its regulation by sex steroids8–13 or the negative impact of retinoic acid,14 almost nothing is known about the physiological control of the meibomian gland in health or disease. This dearth of knowledge is somewhat surprising, given that the meibomian gland is a large sebaceous gland, and numerous articles have been published about the neural, hormonal, and secretagogue modulation of nonocular sebaceous gland tissue.15–24 These reports have shown that the nature of sebaceous gland regulation may vary significantly depending on the type of gland and its skin location. And of particular importance, much of this knowledge of sebaceous gland control has been generated by research with primary, and especially, immortalized sebaceous gland Epithelial Cells.25–28 We seek to advance our understanding of the regulation of meibomian gland function and the mechanisms underlying MGD. We also seek to translate this knowledge into the development of novel and unique therapeutic strategies to treat MGD and evaporative dry eye. Toward that end, we had a twofold purpose in this study: first, to establish a defined culture system for the maintenance of primary Epithelial Cells from human meibomian glands and, second, to immortalize these meibomian gland Epithelial Cells, thereby developing cell cultures that could be useful for identifying factors that regulate meibomian gland Epithelial cell activity.

Roberto P Garofalo - One of the best experts on this subject based on the ideXlab platform.

  • respiratory syncytial virus induces selective production of the chemokine rantes by upper airway Epithelial Cells
    The Journal of Infectious Diseases, 1997
    Co-Authors: Tadahito Saito, Ronald W Deskin, Antonella Casola, Helene A Haeberle, Barbara Olszewska, Peter B Ernst, Rafeul Alam, Pearay L Ogra, Roberto P Garofalo
    Abstract:

    : The presence of histamine and eosinophil cationic protein in nasopharyngeal secretions of infants with respiratory syncytial virus (RSV)-induced bronchiolitis implies the activation of basophil and eosinophil leukocytes, but the specific mechanism of their recruitment has not been elucidated. Chemokines are potent and selective leukocyte chemotactic molecules that are also expressed by airway Epithelial Cells. Therefore, the pattern of chemokines produced in response to RSV infection was investigated in primary cultures of human nose- and adenoid-derived Epithelial Cells. Interleukin-8, growth-related peptide-alpha, and monocyte chemotactic protein-1 were constitutively released by uninfected Epithelial Cells and were not further enhanced by infection with RSV. RANTES (regulated upon activation, normal T cell-expressed and -secreted), which was present in negligible concentrations in uninfected cultures, was strongly induced by RSV infection, in a dose- and time-dependent manner. Through the release of RANTES, Epithelial Cells may control the selective concentration and activation of basophils and eosinophils in RSV-infected airway mucosa.