Human ciliary epithelia in monolayer culture

Kondo, Kazuyoshi; Coca‐Prados, Miguel; Sears, Marvin L.

doi:10.1016/0014-4835(84)90197-0

Cited by 20 publications

(4 citation statements)

References 31 publications

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“…In addition, several attempts have been made to grow CE in tissue culture media after its dissociation and separation (9) from ciliary processes. Some of the differentiated characteristics ofhuman CE cells, such as their structural polarity and epithelial cell type, are retained in primary tissue cultures and have been studied by morphological and immunological criteria (9,10). Activation of adenylate cyclase in human CE cells by catecholamines results in increased intracellular cAMP and significant stimulation of protein phosphorylation, particularly of vimentin (a major cytoskeletal component) (11).…”

mentioning

confidence: 99%

Transformation of human ciliary epithelial cells by simian virus 40: induction of cell proliferation and retention of beta 2-adrenergic receptors.

Coca‐Prados¹,

Wax²

1986

Proc. Natl. Acad. Sci. U.S.A.

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Ciliary epithelial cells derived from human eye were successfully propagated through many generations after transformation with simian virus 40. The cell clone 8-SVHCE was isolated and characterized by immunoprecipitation and pharmacological studies that demonstrated the presence of several functional properties observed in the parent cells of this tissue. Immunoprecipitation revealed the presence of large tumor (T) antigen, and Southern blot analysis showed the incorporation of viral DNA into high molecular weight ciliary epithelial cell DNA. Studies of catecholamine-stimulated cellular cAMP production and of isoproterenol-dependent protein phosphorylation of vimentin in 8-SVHCE indicated the functional conservation of 6-adrenergic receptor-mediated processes that are thought to be important in the regulation of aqueous humor production by the ciliary epithelium in vivo.Ciliary epithelium (CE) in the mammalian eye is thought to play an essential role in the formation of aqueous humor. The composition of aqueous humor is largely dependent on the mechanism of active transport of plasma proteins and electrolytes in these cells. The rate of formation of aqueous humor is modulated by the sympathetic (adrenergic) system (1). The stroma in the ciliary processes is innervated by adrenergic fibers whose terminations remain close to the CE (2). Two structural features of these cells in vivo are (i) a structural polarity where the apical domain of a nonpigmented epithelial (NPE) cell faces the apical domain of a pigmented epithelial (PE) cell and (ii) a physiological, enzyme-based active transport system, Na+,K+-ATPase, located in the basolateral domains in both cell types. The relationship of the structural and physiological polarity in the CE to the regulation of ion transport (i.e., fluid flow from the stroma to the posterior chamber) is unclear.Previous studies (3-5) using crude membrane preparations from whole ciliary processes have indicated the presence of 8-adrenergic receptors in the ciliary epithelium of eyes from a variety of mammalian species. It is possible, however, that vascular endothelial cells from microvessels in the stroma of ciliary processes may have contributed to the stimulation of adenylate cyclase by 83-adrenergic receptors that was observed in these preparations. Attempts have been made to dissociate the CE cells from the stroma tissue to measure the properties and characteristics of the P-adrenergic receptor/ adenylate cyclase system in a mixed population of NPE and PE cells (6), after their separation in a density gradient (7), and in isolated NPE cells (8). In these studies, p-adrenergic receptors were found in both cell types. In addition, several attempts have been made to grow CE in tissue culture media after its dissociation and separation (9) from ciliary processes. Some of the differentiated characteristics ofhuman CE cells, such as their structural polarity and epithelial cell type, are retained in primary tissue cultures and have been studied by morphological and immunological...

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mentioning

confidence: 99%

Transformation of human ciliary epithelial cells by simian virus 40: induction of cell proliferation and retention of beta 2-adrenergic receptors.

Coca‐Prados¹,

Wax²

1986

Proc. Natl. Acad. Sci. U.S.A.

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“…The phosphorylation of GSK3β allows the release of dephosphorylated β‐catenin from its inactive complex, to translocate into the cell nucleus where it can induce translation of mRNA involved in cell adhesion such as LEF1, Axin2 and β‐catenin 30,33,34 . We showed that when a relatively low number of NPCE‐derived EVs were incubated with TM cells, a significant decrease in the expression of pGSK3β and β‐catenin was found, while the exposure of TM cells to 10 times higher concentration of NPCE EVs resulted in the abolishment of the down‐regulation expression induced on TM pGSK3β and β‐catenin 35 . Elevation of cytosolic β‐catenin contributes to the increase in the expression levels of the adhesion molecule, cadherin in general and TM cytoplasm, 31,36‐39 which is manifested in the development of POAG 40,41 …”

Section: Introductionmentioning

confidence: 83%

“…30,33,34 We showed that when a relatively low number of NPCE-derived EVs were incubated with TM cells, a significant decrease in the expression of pGSK3β and β-catenin was found, while the exposure of TM cells to 10 times higher concentration of NPCE EVs resulted in the abolishment of the down-regulation expression induced on TM pG-SK3β and β-catenin. 35 Elevation of cytosolic β-catenin contributes to the increase in the expression levels of the adhesion molecule, cadherin in general and TM cytoplasm, 31,[36][37][38][39] which is manifested in the development of POAG. 40,41 Several papers demonstrated that EVs have a role in ECM formation as specific components of their cargo are responsible for changes in collagen fibre formation, and adhesion assembly 42 in different cells 43,44 and particularly in the TM.…”

Section: Introductionmentioning

confidence: 99%

Trabecular meshwork's collagen network formation is inhibited by non‐pigmented ciliary epithelium‐derived extracellular vesicles

Tabak

Schreiber‐Avissar

Beit‐Yannai

2021

J Cellular Molecular Medi

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The present research aims to determine whether the application of non‐pigmented ciliary epithelium cells derived extracellular vesicles to human trabecular meshwork cells affects the formation and secretion of collagen type I to the extracellular matrix formation. Following the extraction of non‐pigmented ciliary epithelium derived extracellular vesicles by a precipitation method, their size and concentration were determined using tunable resistive pulse sensing technology. Extracellular vesicles were incubated with trabecular meshwork cells for 3 days. Morphological changes of collagen type I in the extracellular matrix of trabecular meshwork cells were visualized using confocal microscopy and scanning electron microscopy. A Sirius Red assay was used to determine the total amount of collagen. Finally, collagen type I expression levels in the extracellular matrix of trabecular meshwork cells were quantified by cell western analysis. We found that non‐pigmented ciliary epithelium extracellular vesicles were very effective at preventing collagen fibres formation by the trabecular meshwork cells, and their secretion to the extracellular matrix was significantly reduced (P < .001). Morphological changes in the extracellular matrix of trabecular meshwork cells were observed. Our study indicates that non‐pigmented ciliary epithelium extracellular vesicles can be used to control collagen type I fibrillogenesis in trabecular meshwork cells. These fibrils net‐like structure is responsible for remodelling the extracellular matrix. Moreover, we suggest that targeting collagen type I fibril assembly may be a viable treatment for primary open‐angle glaucoma abnormal matrix deposition of the extracellular matrix.

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“…Valuable information has been obtained utilizing excised iris ciliary body preparations (1,2). The complex geometry of this preparation and of the ciliary tissue itself, and the failure of the preparation to support adequate flow of solute (3) and solvent, however, have promoted the use of separately cultured nonpigmented and pigmented epithelial cells (4,5). In these cultures and in fresh tissues (6), studies of solute uptake (7), of membrane potentials (8), etc.…”

Section: Introductionmentioning

confidence: 98%

Transepithelial Transport of Ascorbic Acid by the Isolated Intact Ciliary Epithelial Bilayer of the Rabbit Eye

Mead¹,

Sears²,

Sears³

1996

Journal of Ocular Pharmacology and Therapeutics

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The purpose of these experiments was to test whether the isolated intact epithelial bilayer derived from rabbit ciliary processes transports ascorbic acid and to what degree the transport rate in vitro corresponds to the in vivo process. The intact ciliary epithelial bilayer of the rabbit eye isolated by perfusion was mounted in a particularly constructed Ussing type chamber. Fluxes were measured by additions of 14C ascorbate to the hemichamber on either the pigmented epithelium (PE) or the nonpigmented epithelium (NPE) side where equal concentrations of ascorbate from .02 to 2.0 mM were present. Samples were taken at intervals thereafter and counted in a liquid scintillation counter. The experiments were done under short circuit conditions to avoid the possible influence of fluctuating currents upon the movement of ascorbate. Like the earlier iris ciliary body preparations, separation of ascorbate fluxes is also done by the isolated intact ciliary epithelial bilayer, and the transport of ascorbic acid proceeds by saturation kinetics. The uptake process is accomplished entirely by the pigmented epithelium (PE). The Km of the process is 0.97 mM, and Vmax was valued at 130 nM/L/hr. Thus, assuming an aqueous flow rate of 2 microliters/min, the transfer of ascorbic acid across the bilayer occurs at a rate required to maintain the ordinary millimolar concentration of ascorbic acid in the aqueous humor found in vivo.

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Human ciliary epithelia in monolayer culture

Cited by 20 publications

References 31 publications

Transformation of human ciliary epithelial cells by simian virus 40: induction of cell proliferation and retention of beta 2-adrenergic receptors.

Transformation of human ciliary epithelial cells by simian virus 40: induction of cell proliferation and retention of beta 2-adrenergic receptors.

Trabecular meshwork's collagen network formation is inhibited by non‐pigmented ciliary epithelium‐derived extracellular vesicles

Transepithelial Transport of Ascorbic Acid by the Isolated Intact Ciliary Epithelial Bilayer of the Rabbit Eye

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