摘要:

Efforts to grow differentiated pigment epithelial cells have led to a characterization of the growth kinetics of spontaneously established, continuously growing, human retinal pigment epithelial (PE) cell line 0041 on several biomatrices. These substrates were prepared from (a) placental and amniotic membrane, (b) commercially available basement membrane matrix (Matrigel), (c) dishes coated with extracellular matrix secreted by endothelial cells (ECM), (d) dishes coated with collagen IV and/or laminin, (e) dishes coated with collagen 1 and/or fibronectin.Our findings suggest that tissue culture plastic and dishes coated with collagen IV alone promote higher cell densities, while highest plating efficiency (24 hrs) was seen on tissue culture plastic and Matrigel. The highest degree of differentiation (epithelioid appearance, apical villi and junctional complexes) was seen in cells plated on dishes coated with collagen IV and extracellular matrix secreted by endothelial cells. Cells were epithelioid and polarized on those two substrates; they expressed fine finger-shaped villi and the highest degree of cell contact (in the form of junctions). Cells grown on Matrigel looked like fibroblasts and became deeply pigmented; however, the nature of the pigment remains to be determined. Collagen IV and ECM coated dishes, therefore, are most suitable for cultures of human PE cell line 0041 because they provide higher cell densities while retaining the differentiated state. This is the first report where an established pigmented epithelial cell line has been induced to become differentiated by use of extracellular matrices and extracellular matrix components.

ISSN:0271-3683    

DOI:10.3109/02713689109024126

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

We examined the incooration of fluoresceinated low-density lipoprotein (LDG and acetylated or acetoacetylated low-density lipoprotein (A-LDL or AA-LDL) by a number of ocular cells in culture. All the cells investigated, including bovine, monkey, human trabecular meshwork cells, human corneal endothelial cells, human corneal stromal cells and human scleral cells, took u fluorescently labeled LDL. The bovine, monkey and human trabecular meshwork cells showed the stronest fluorescence reactions. In addition, we found that tae trabecular meshwork cells became fluorescent after incubations with labeled A-LDL or AA-LDL. They were the only cell type examined that possessed this capacity. The fluorescence intensity was markedly diminished by adding to the incubation solution either fucoidin, a competitive inhibitor of modified LDL uptake, unlabeled A-LDL or AA-LDL. The trabecular meshwork cellsin situalso became brightly labeled after exposure to fluoresceinated native LDL, A-LDL or AA-LDL. The uptake of modified LDL separated the trabecular meshwork cells from other types of ocular cells, which may be used to aid identification of trabecular meshwork cells in culture as well asin situ.This proerty also suggested that trabecular meshwork cells may Kave some functional similarities to macrophages.

ISSN:0271-3683    

DOI:10.3109/02713689109024127

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

Hyperkeratinization of meibomian glands has been postulated to cause gland dysfunction. Recent investigations on rabbits show that keratin proteins are indeed present in the meibomian fluids of these animals. In this report we present our findings on the presence of these water-insoluble proteins in human meibomian secretions. 6 anti-cytokeratin antibodies, CK8, 18, 19, CK7, CK8, CK14, CK19 and AEl/AE3 were used against the keratin proteins expressed from the human meibomian fluids. Using the imoblotting (dot blot) technique, abnormal waxy meibomian fluids obtained from subjects diagnosed to have meibomian gland dysfunction (MGD) were compared to normal clear meibomian fluids. The results show that keratins are present in a higher concentration (10%) in the abnormal human meibomian excreta as compared to the normals. Even though the presence of protein markers for keratinization in the abnormal meibomian excreta were not shown, the increased presence of keratin proteins in the abnormal meibomian fldds suggests that, in MGD patients, hyperkeratinization of ductal epithelium may have taken place. More keratin proteins (possibly those of higher molecular weights) were produced in addition to the keratin proteins normally produced by the duct epithelium. The increased amount of keratin proteins in the abnormal meibomian fluids may be explained by the susceptibility of duct epithelium to undergo the process of hyperkeratinization as postulated by other researchers.

ISSN:0271-3683    

DOI:10.3109/02713689109024128

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

Antibodies specific for protein phosphotyrosyl residues were used to localize sites of protein tyrosine kinase activity in the optic tract of the developing chick by immunoperoxidase staining. In the stage 34 (day 8) chick embryo, phosphotyrosine-modified proteins were abundant within outgrowing neuronal processes in the optic nerve head and nerve fiber layer of the retina, and in the developing stratum opticum at the surface of the optic tectum. These sites corresponded to regions where migrating growth cones and fasciculating bundles of some, but not all, retinal ganglion cell axons were located. Phosphotyrosine-modified proteins were also abundant in and highly restricted to the process-rich layers of the embryonic optic tectum. Phosphotyrosine immunoreactivity decreased dramatically in the corresponding regions of the optic tract of the adult chicken, indicating that protein tyrosine phosphorylation occurred principally in developing, rather than mature, neuronal processes. These findings are in accord with the idea that protein tyrosine phosphorylation may be important in cell-cell or cell-substratum interactions of ganglion cell axons.

ISSN:0271-3683    

DOI:10.3109/02713689109024129

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

The ability of rabbit corneas to undergo energy-dependent deturgescence was examined after the corneas were stored at 4°C in UW solution, M-K media, or selected modifications of these media. All corneas slowly increased in thickness during storage, despite the presence of colloidal osmotic agents. Corneas stored for 2.5 days in M-K became slightly thinner when cultured over a 24-hour period. Corneas stored in UW swelled quickly in culture and became too opaque to measure within three hours. Corneas stored in UW with 1.8 mM CaC12swelled transiently, then maintained their thickness and exhibited deturgescence in the latter stages of the culture period. Deturgescence of corneas stored for 7 days in M-K was only slightly worse than those stored for 2.5 days. Corneas stored for 7 days in UW, however, became opaque almost imnediately in culture and those stored in calcium-supplemented UW became opaque within 4.5 hours. Replacement of the dextran in M-K with hydroxyethyl starch produced a slower rate of corneal swelling during storage and a substantially better corneal deturgescence profile during culture. Use of high concentrations of potassium ion in the M-K formulation had no significant effect on post-storage deturgescence. Replacement of glucose in M-K with the impermeable sugar, raffinose had a slight deleterious effect on corneal deturgescence in subsequent culture. Use of the impermeable anions gluconate or lactobionate to replace chloride ion caused profound corneal swelling during culture, compared with those stored in M-K. These experiments show that UW solution is inferior to M-K at preserving post-storage corneal function. Furthermore, most of the components of uw solution are inferior to their analogous components of M-K at maintaining corneal function during storage. The hydroxyethyl starch used in UW solution, however, appears to have advantages over dextran during and after corneal storage.

ISSN:0271-3683    

DOI:10.3109/02713689109024130

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

Interleukin-1 (IL-1) has been strongly implicated as an inflammatory mediator in anterior uveitis. Recently, solubilized receptors have been utilized to block the binding of viruses to cell membranes or to inhibit cytokine activity. We have tested the activity of an intravitreally injected soluble, human interleukin-1 receptor in a rabbit model of IL-1-induced inflammation. 3 ug of the soluble receptor markedly inhibited both the cellular infiltration and the protein extravasation that followed 6 hours after an intravitreal injection of 10.5 ng of recombinant human interleukin-1 alpha. The efficacy of the soluble receptor was less marked 24 hours after the IL-1 injection. The cellular infiltrate was not reduced at all if the IL-1 receptor was injected 2 hours after the IL-1. The activity of the soluble receptor deserves further study as a therapeutic modality for inflammatory eye disease.

ISSN:0271-3683    

DOI:10.3109/02713689109024131

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

High molecular (designated Sv,>3K) and low molecular (designated Sv, c3K) fractions were prepared by filtration of porcine vitreous extracts through a membrane filter with a molecular weight cut-off of 3,000 daltons. Both fractions inhibited mitogen-stimulated proliferation of lymphocytes from rat spleen, as determined by [3H]-thymidine incorporation. The inhibitory activity of Sv,>3K was markedly enhanced by acid treatment and abolished almost completely by incubation with anti-tiansfonning growth factor beta (TGF-β) antibody. The major immunosuppressive factor in Sv,>3K was therefore concluded to be TGF-βOn the other hand, the inhibitory activity of Sv,<3K was not affected by acid treatment or by incubation with anti-TGF-p antibody but was decreased by proteolytic treatment. From these results the immunosuppressive factor in Sv,3K and Sv,<3K were reversible and therefore not cytotoxic. Both factors seemed to suppress lymphoproliferation without affecting the expression of Interleukin-2 receptor, CD4 and CD8 on the cell surface of cultured lymphocytes.

ISSN:0271-3683    

DOI:10.3109/02713689109024132

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

The presence and distribution of coated pits (CPs) and coated vesicles (CVs) in the rat lens were studied by thm-section electron microscopy (TEM) and wheat germ agglutinin-horseradish peroxidase (WGA-HRP) as a tracer. TEM revealed that CPs and CVs were∼150 nm in diameter, of which the characteristic clathrin coat was∼20 nm thick. CPs and CVs were found in both epithelium and superficial fiber cells of the entire lens, and were distributed preferentially along the basal membrane facing the lens capsule. It was estimated that more than 80% of CPs and CVs in the entire epithelium were seen along the basal membrane. The number of CPs and CVs along the basal membrane in the equatorial epithelium (4.4 per 10μm membrane) was similar to that at the central zone (3.8 per 10μm membrane), but there was a significant increase along the apical and lateral surfaces of the equatorial epithelium compared to that of the central epithelium, although the overall number was considerably smaller. In the lens fibers, CPs and CVs were usually found within 2-3 superficial layers of fiber cells. The number of CPs and CVs along the basal membrane of young fibers at the post-equatorial region (3.1 per 10μm membrane) was 3-fold greater than that of the mature fibers at the posterior polar area (1 per 10μm membrane). Thus, CPs and CVs along the entire basal membrane showed a gradual decrease in number from the anterior (and equatorial) regions to the posterior polar surface of the lens. WGA-HRP experiments showed that approximately 80 % of tracer-carrying pits and vesicles were also found along the basal surface of the equatorial epithelium. This study suggests that a polarized distribution of CPs and CVs along the basal surface of epithelium and superficial fiber cells may facilitate receptor-mediated endocytosis of important macromolecules directly from the aqueous humor and vitreous body into metabolically active lens cells.

ISSN:0271-3683    

DOI:10.3109/02713689109024133

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

By their implication in the organization of the intermediate filament (IF) cytoskeleton, IF-associated proteins (IFAPs) can delineate subsets of the same IF type within a cell; moreover, they are proving useful as markers of the differentiation states of certain cells. For these reasons the expression of the vimentin-associated IFAP-300kD was investigated in the constantly differentiating cell lineage of the adult bovine lens. Immunofluorescence microscopy and immunohlot analysis were employed using a monoclonal anti-IFAP-300kD and a rabbit anti-lens vimentin. Cultures of adult lens epithelial cells were immunopositive for the IFAP. By double-label studies the IFAP-300kD pattern co-localized with that of the vimentin-type IF; moreover, the IFAP pattern co-distributed with that of both colchicine-sensitive and -insensitive IF systems. IFAP-300kD was also present in a co-distributing pattern with vimentin IF in fresh lens epithelial cells on whole mounts. There was a differential expression of the IFAP in the lens fiber cells in that those of the cortex exhibited the IFAP and vimentin IF, while both proteins were absent from the nuclear fiber cells. Furthermore, there was a differential distribution of the IFAP within the cortical fiber cells in that the IFAP localized only with a paramembranal subset of IF. Immunoblot analysis supported the presence of IFAP-300kD in the lens cytoskeletal fraction. IFAP-300kD thus identified a subset of vimentin IF whose location may have functional significance for the cortical fiber cell. The changes in the IFAP's expression and distribution pattern throughout lens cell differentiation in the adult organ suggest the usefulness of IFAP-300kD as a potential marker in studying lens cell differentiationin vitro.

ISSN:0271-3683    

DOI:10.3109/02713689109024134

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

Rabbits entrained in a daily light-dark environment show a circadian elevation of intraocular pressure (IOP) around the onset of dark. It was reported that concentration of cyclic AMP (CAMP) in aqueous humor increases significantly during this time period. Whether or not the increase of ocular CAMP-mediated activities is related to the circadian elevation of IOP is unclear. Light-dark entrained rabbits maintain the circadian IOP elevation in a constant dark environment. Corresponding to this IOP elevation in the constant dark, no change of aqueous humor cAMP concentration was found. Thus, the circadian IOP elevation in the constant dark is probably unrelated to the CAMP-mediated activities. This finding also suggests that a significant portion of the circadian IOP elevation in the light-dark environment is unrelated to the CAMP-mediated activities.

ISSN:0271-3683    

DOI:10.3109/02713689109024135

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor