scholarly journals Localization of laminin, type IV collagen, fibronectin, and heparan sulfate proteoglycan in chick retinal pigment epithelium basement membrane during embryonic development.

1985 ◽  
Vol 33 (7) ◽  
pp. 665-671 ◽  
Author(s):  
K Turksen ◽  
J E Aubin ◽  
J Sodek ◽  
V I Kalnins
Keyword(s):  
Heparan Sulfate ◽  
Type Iv Collagen ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Heparan Sulfate Proteoglycan ◽  
Sulfate Proteoglycan ◽  
Rpe Cells ◽  
Type Iv

Type IV collagen, laminin, heparan sulfate proteoglycan, and fibronectin were localized in the basement membrane (BM) of chick retinal pigment epithelium (RPE) during various stages of eye development. At different times over a 4-17 day period after fertilization, chick embryo eyes were dissected, fixed in periodate-lysine-paraformaldehyde, and 6 micron frozen sections through the central regions of the eye were prepared. Sections were postfixed in -20 degrees C methanol and stained immediately by indirect immunofluorescence using sheep anti-mouse laminin, sheep antimouse type IV collagen, rabbit anti-mouse heparan sulfate proteoglycan, and mouse monoclonal anti-porcine plasma fibronectin. Fluorescein-labeled F(ab')2 fragments of the appropriate immunoglobulins (IgGs) were used as secondary antibodies. Laminin could be readily demonstrated in the BM of the RPE during all stages of development. The staining for type IV collagen, fibronectin, and heparan sulfate proteoglycan HSPG) was less intense than that for laminin, but was also localized in the BM along the basal side of the RPE. In addition to staining the BM, antiserum to HSPG, gave a diffuse labeling from day 9 onward, above the RPE extending into the region of the photoreceptors. Whereas the intensity of staining generally increased between day 4 and day 17 of development, the distribution of the different BM components did not change. Hence the presence of type IV collagen, laminin, fibronectin, and HSPG in the BM of RPE in vivo during all the stages of development investigated supports the concept that these macromolecules are important basic components of this, and other, BMs. Furthermore, these results indicate that the composition of the BM of RPE cells in vivo is similar to the BM material deposited by RPE cells in vitro (Turksen K, Aubin JE, Sodek JE, Kalnins VI: Collagen Rel Res, 4:413-426, 1984) and that the in vitro cultures can therefore serve as a useful model for studying BM formation.

The cytoskeletal elements of human retinal pigment epithelium: in vitro and in vivo

1988 ◽  
Vol 91 (2) ◽  
pp. 303-312
Author(s):  
N.M. McKechnie ◽  
M. Boulton ◽  
H.L. Robey ◽  
F.J. Savage ◽  
I. Grierson
Keyword(s):  
Retinal Pigment Epithelium ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Cytokeratin 18 ◽  
Rpe Cells ◽  
Human Retinal Pigment Epithelium ◽  
Cytoskeletal Elements

The cytoskeletal elements of normal (in situ) and cultured human retinal pigment epithelium (RPE) were studied by a variety of immunocytochemical techniques. Primary antibodies to vimentin and cytokeratins were used. Positive immunoreactivity for vimentin was obtained with in situ and cultured material. The pattern of reactivity obtained with antisera and monoclonals to cytokeratins was more complex. Cytokeratin immunoreactivity could be demonstrated in situ and in cultured cells. The pattern of cytokeratin expression was similar to that of simple or glandular epithelia. A monoclonal antibody that specifically recognizes cytokeratin 18 identified a population of cultured RPE cells that had particularly well-defined filamentous networks within their cytoplasm. Freshly isolated RPE was cytokeratin 18 negative by immunofluorescence, but upon culture cytokeratin 18 positive cells were identifiable. Cytokeratin 18 positive cells were identified in all RPE cultures (other than early primaries), regardless of passage number, age or sex of the donor. In post-confluent cultures cytokeratin 18 cells were identified growing over cytokeratin 18 negative cells, suggesting an association of cytokeratin 18 immunoreactivity with cell proliferation. Immunofluorescence studies of retinal scar tissue from two individuals revealed the presence of numerous cytokeratin 18 positive cells. These findings indicate that RPE cells can be identified by their cytokeratin immunoreactivity and that the overt expression of cytokeratin 18 may be associated with proliferation of human RPE both in vitro and in vivo.

JAM-C maintains VEGR2 expression to promote retinal pigment epithelium cell survival under oxidative stress

2017 ◽  
Vol 117 (04) ◽  
pp. 750-757
Author(s):  
Xin Jia ◽  
Chen Zhao ◽  
Qishan Chen ◽  
Yuxiang Du ◽  
Lijuan Huang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Retinal Pigment Epithelium ◽  
Cell Survival ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Pigment Epithelium Cell ◽  
Photoreceptor Cells ◽  
Rpe Cells

SummaryJunctional adhesion molecule-C (JAM-C) has been shown to play critical roles during development and in immune responses. However, its role in adult eyes under oxidative stress remains poorly understood. Here, we report that JAM-C is abundantly expressed in adult mouse retinae and choroids in vivo and in cultured retinal pigment epithelium (RPE) and photoreceptor cells in vitro. Importantly, both JAM-C expression and its membrane localisation are downregulated by H2O2-induced oxidative stress. Under H2O2-induced oxidative stress, JAM-C is critically required for the survival of human RPE cells. Indeed, loss of JAM-C by siRNA knockdown decreased RPE cell survival. Mechanistically, we show that JAM-C is required to maintain VEGFR2 expression in RPE cells, and VEGFR2 plays an important role in keeping the RPE cells viable since overexpression of VEGFR2 partially restored impaired RPE survival caused by JAM-C knockdown and increased RPE survival. We further show that JAM-C regulates VEGFR2 expression and, in turn, modulates p38 phosphorylation. Together, our data demonstrate that JAM-C plays an important role in maintaining VEGR2 expression to promote RPE cell survival under oxidative stress. Given the vital importance of RPE in the eye, approaches that can modulate JAM-C expression may have therapeutic values in treating diseases with impaired RPE survival.

scholarly journals Heterogenous distribution of type IV collagen, entactin, heparan sulfate proteoglycan, and laminin among renal basement membranes as demonstrated by quantitative immunocytochemistry.

1989 ◽  
Vol 37 (6) ◽  
pp. 885-897 ◽  
Author(s):  
M Desjardins ◽  
M Bendayan
Keyword(s):  
Heparan Sulfate ◽  
Type Iv Collagen ◽  
Protein A ◽  
Heparan Sulfate Proteoglycan ◽  
Basement Membranes ◽  
Sulfate Proteoglycan ◽  
Type Iv ◽  
Membrane Components ◽  
Convoluted Tubules ◽  
Basement Membrane Components

Type IV collagen, entactin, heparan sulfate proteoglycan, and laminin antigenic sites were revealed on various rat renal basement membranes by use of protein A-gold immunocytochemistry. The basement membranes of the proximal and distal convoluted tubules, those of Bowman's capsule and glomerulus, and the mesangial matrix were labeled for all the antigens but to differing extents. Control experiments confirmed the specificity of these labelings. Quantitative evaluation revealed an important heterogeneity for each antigen among the various basement membranes. This heterogeneity suggests that the basement membrane components must arrange themselves in different ways, possibly to account for differences in functional properties of the various renal structures.

scholarly journals Immunogold quantitation of laminin, type IV collagen, and heparan sulfate proteoglycan in a variety of basement membranes.

1988 ◽  
Vol 36 (3) ◽  
pp. 271-283 ◽  
Author(s):  
D S Grant ◽  
C P Leblond
Keyword(s):  
Heparan Sulfate ◽  
Type Iv Collagen ◽  
Collagen Iv ◽  
Heparan Sulfate Proteoglycan ◽  
Basement Membranes ◽  
Enamel Organ ◽  
Sulfate Proteoglycan ◽  
Lamina Densa ◽  
Type Iv ◽  
Reichert's Membrane

A series of basement membranes was immunolabeled for laminin, type IV collagen, and heparan sulfate proteoglycan in the hope of comparing the content of these substances. The basement membranes, including thin ones (less than 0.3 micron) from kidney, colon, enamel organ, and vas deferens, and thick ones (greater than 2 micron), i.e., Reichert's membrane, Descemet's membrane, and EHS tumor matrix, were fixed in formaldehyde, embedded in Lowicryl, and treated with specific antisera or antibodies followed by anti-rabbit immunoglobulin bound to gold. The density of gold particles, expressed per micron2, was negligible in controls (less than or equal to 1.1), but averaged 307, 146, and 23, respectively, for laminin, collagen IV, and proteoglycan over the thick basement membranes (except for Descemet's membranes, over which the density was 16, 5, and 34, respectively) and 117, 72, and 64, respectively, over the lamina densa of the thin basement membranes. Lower but significant reactions were observed over the lamina lucida. Interpretation of the gold particle densities was based on (a) the similarity between the ultrastructure of most thick basement membranes and of the lamina densa of most thin basement membranes, and (b) the biochemical content of the three substances under study in the EHS tumor matrix (Eur J Biochem 143:145, 1984). It was proposed that thick basement membranes (except Descemet's) contained more laminin and collagen IV but less heparan sulfate proteoglycan than the lamina densa of thin basement membranes. In the latter, there was a fair variation from tissue to tissue, but a tendency towards a similar molar content of the three substances.

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