scholarly journals Biosynthesis of sulphated macromolecules by rabbit lens epithelium. I. Identification of the major macromolecules synthesized by lens epithelial cells in vitro.

1984 ◽  
Vol 99 (3) ◽  
pp. 852-860 ◽  
Author(s):  
J G Heathcote ◽  
R W Orkin
Keyword(s):  
Molecular Weight ◽  
Epithelial Cells ◽  
Basement Membrane ◽  
Culture Medium ◽  
Cell Layer ◽  
Heparan Sulphate ◽  
Lens Epithelial Cells ◽  
Heparan Sulphate Proteoglycan ◽  
Rabbit Lens

Rabbit lens epithelial cells synthesize and secrete a variety of [35S]sulphate-labeled glycoconjugates in vitro. Associated with the cell layer, and with the medium, was a high molecular weight glycoconjugate(s) that contained heparan sulphate which was apparently covalently linked to sulphated glycoprotein. This component(s) was eluted in the void volume of a Sepharose CL-2B column and could not be fractionated by detergent treatment or extraction with lipid solvents. The cell layer also contained glycosaminoglycans (72% heparan sulphate, 28% chondroitin sulphate), as well as a small proportion of a low molecular weight sulphated glycoprotein. The major 35S-labeled species secreted into the medium were sulphated glycoproteins with approximate molecular weights of 120,000 and 35,000 together with a heparan sulphate proteoglycan. This proteoglycan could be precipitated from the culture medium with 30% saturated (NH4)2SO4 and eluted from Sepharose CL-4B columns at approximately the same position (Kav = 0.15) as heparan sulphate proteoglycans described in the basement membrane of the EHS "sarcoma" (Hassell, J. R., P. G. Robey, H. J. Barrach, J. Wilczek, S. I. Rennard, and G. R. Martin, 1980, Proc. Natl. Acad. Sci. USA, 77:4494-4498) and of the mouse mammary epithelium (David, G., and M. Bernfield, 1981, J. Cell Biol., 91:281-286). Its presence in the culture medium was unanticipated but may be explained by the inability of these cultures to deposit a basement membrane when grown on a plastic surface. The relationship of this heparan sulphate proteoglycan to the lens epithelial basement membrane is the subject of the following paper.

scholarly journals Biosynthesis of sulphated macromolecules by rabbit lens epithelium. II. Relationship to basement membrane formation.

1984 ◽  
Vol 99 (3) ◽  
pp. 861-869 ◽  
Author(s):  
J G Heathcote ◽  
R R Bruns ◽  
R W Orkin
Keyword(s):  
Basement Membrane ◽  
Type I Collagen ◽  
Heparan Sulphate ◽  
Significant Proportion ◽  
Type I ◽  
Heparan Sulphate Proteoglycan ◽  
Membrane Formation ◽  
Sulphate Proteoglycan ◽  
Type Iv ◽  
Rabbit Lens

Rabbit lens epithelial cells display a similar "cobblestone" morphology and produce the same complement of sulphated macromolecules (also see Heathcote, J.G., and R.W. Orkin, 1984, J. Cell Biol., 99:852-860) whether grown on plastic or glass, dried films of gelatin or type IV collagen with laminin, or on gels of type I collagen. There was no evidence of basement membrane formation by these cells when they were grown on plastic, glass, or dried films. In contrast, cultures that had been grown on gels deposited a discrete basement membrane that followed the contours of the basal surfaces of the cells and in addition, they secreted amorphous basement membrane-like material that diffused into the interstices of the gel and associated with the collagen fibrils of the gel. A significant proportion (approximately 70%) of the heparan sulphate proteoglycan fraction that was secreted into the culture medium (fraction MI) when the cells were grown on plastic became associated with the cell-gel layer in the gel cultures. Further, when basement membrane was isolated by detergent extraction, greater than 90% of the 35S-labeled material present was in this heparan sulphate proteoglycan.

scholarly journals Characterization of proteoglycans synthesized by human adult glomerular mesangial cells in culture

1991 ◽  
Vol 277 (1) ◽  
pp. 81-88 ◽  
Author(s):  
G J Thomas ◽  
R M Mason ◽  
M Davies
Keyword(s):  
Culture Medium ◽  
Mesangial Cells ◽  
Cell Layer ◽  
Heparan Sulphate ◽  
Glomerular Mesangial Cells ◽  
Heparan Sulphate Proteoglycan ◽  
Dermatan Sulphate ◽  
Sulphate Proteoglycan ◽  
Human Adult ◽  
Core Proteins

1. The newly synthesized proteoglycans from human adult glomerular mesangial cells labelled in vitro for 24 h with [35S]sulphate have been characterized using biochemical and immunological techniques. 2. The following proteoglycans were identified (% of total synthesized). (i) A large chondroitin sulphate proteoglycan, CSPG-I, Mr approximately 1 x 10(6) (10.6%). This proteoglycan consisted of a protein core of Mr approximately 4 x 10(5) and glycosaminoglycan chains of Mr 2.5 x 10(4), and was present in both the cell layer and the culture medium. (ii) A major small dermatan sulphate proteoglycan, DSPG-I, Mr 3.5 x 10(5) (46%), which was mainly located in the culture medium. (iii) A second minor small dermatan sulphate, DSPG-II, Mr approximately 2 x 10(5) (9.8%). This molecule was exclusively located in the culture medium. (iv) A large heparan sulphate proteoglycan, HSPG-I, Mr 8 x 10(5) (3.3%). (v) A second large heparan sulphate proteoglycan HSPG-II, Mr approximately 6 x 10(5) (23%). HSPG-I and HSPG-II were extracted from both the culture medium and the cell layer. 3. Western blot analysis of the core proteins released by chondroitin ABC lyase treatment of DSPG-I and DSPG-II identified these dermatan sulphate proteoglycans as biglycan and decorin respectively. Both DSPG-I and DSPG-II had core proteins of Mr 45,000. 4. The cell-layer-associated forms of CSPG-I, HSPG-I and HSPG-II were accessible to limited trypsin treatment, bound to octyl-Sepharose and could be inserted into liposomes, indicating a possible cell membrane location. 5. Pulse-chase experiments indicated that the cell-layer-associated [35S]proteoglycans undergo limited metabolism to inorganic [35S]sulphate, the majority of which is accounted for by the degradation of HSPG-II and to a lesser extent DSPG-I.

Differential Effects of Fibronectin-DerivedOligopeptides on the Attachment of Rabbit Lens Epithelial Cells in vitro

1996 ◽  
Vol 28 (4) ◽  
pp. 201-208 ◽  
Author(s):  
Tetsuo Sasabe ◽  
Yuzo Suwa ◽  
Akira Kiritoshi ◽  
Masamitsu Doi ◽  
Takenosuke Yuasa ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Lens Epithelial Cells ◽  
Differential Effects ◽  
Rabbit Lens

scholarly journals Proteoglycan production by human glomerular visceral epithelial cells and mesangial cells in vitro

1995 ◽  
Vol 307 (3) ◽  
pp. 759-768 ◽  
Author(s):  
N F van Det ◽  
J van den Born ◽  
J T Tamsma ◽  
N A M Verhagen ◽  
L P W J van den Heuvel ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Basement Membrane ◽  
Glomerular Basement Membrane ◽  
Culture Medium ◽  
Mesangial Cells ◽  
Core Protein ◽  
Cell Layer ◽  
Hybrid Molecule ◽  
Chondroitinase Abc ◽  
Sulphate Proteoglycan

Proteoglycans metabolically labelled with [35S]sulphate and [3H]glucosamine or [3H]leucine were isolated from the incubation medium and cell layer of human adult mesangial cells and glomerular visceral epithelial cells using sequential DEAE chromatography purification steps followed by gel-filtration chromatography. The proteoglycan composition of each peak was analysed by treatment with HNO2, chondroitinase ABC or chondroitinase AC followed by chromatography on Sephadex G-50 columns. Heparan sulphate proteoglycan (HSPG) and dermatan sulphate proteoglycan were detected in both the culture medium and cell layer of mesangial cells. Culture medium of glomerular visceral epithelial cells contained HSPG and a second proteoglycan with the properties of a hybrid molecule containing HS and chondroitin sulphate (CS). The cell layer contained HSPG and CSPG. Detailed analysis of the hybrid molecule revealed that it had an apparent molecular mass of 400 kDa. SDS/PAGE of hybrid molecules, after treatment with heparitinase and chondroitinase ABC, revealed a core protein of 80 kDa. Using 1.8% polyacrylamide/0.6% agarose-gel electrophoresis, we deduced that the HS and CS were independently attached to one core protein. Because glomerular-basement-membrane HSPG is thought to be derived from mesangial cells and glomerular visceral epithelial cells and this molecule is involved in several kidney diseases, we investigated its synthesis in more detail. Anti-(rat glomerular-basement-membrane HSPG) monoclonal antibodies (JM403) and anti-(human glomerular-basement-membrane HSPG) polyclonal antibodies (both antibodies known to react with the large basement-membrane HSPG, perlecan) reacted strongly with HSPG obtained from both mesangial cells and glomerular visceral epithelial cells. However, the hybrid molecule did not react with these antibodies, suggesting that the HS side chain and the core protein were different from glomerular-basement-membrane HSPG. To quantify HS we performed an inhibition ELISA using mouse antibodies specific for glomerular-basement-membrane HS glycosaminoglycan side chains. Glomerular visceral epithelial cells produced significantly higher levels of HS (between 197.56 and 269.40 micrograms/72 h per 10(6) cells) than mesangial cells (between 29.8 and 45.5 micrograms/72 h per 10(6) cells) (three different cell lines; n = 3; P < 0.001). HS production by these cells was inhibited by cycloheximide, revealing that it was synthesized de novo. Expression of perlecan mRNA, demonstrated using reverse transcriptase PCR, was different in the two cell types. We conclude that glomerular visceral epithelial cells and mesangial cells have characteristic patterns of proteoglycan production. Glomerular visceral epithelial cells produced a hybrid proteoglycan containing CS and HS independently attached to its core protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Donor age influences the growth of rabbit lens epithelial cells in vitro

1981 ◽  
Vol 21 (1) ◽  
pp. 11-23 ◽  
Author(s):  
John R. Reddan ◽  
Thomas B. Friedman ◽  
M. Kazem Mostafapour ◽  
Robert L. Bondy ◽  
Steven H. Sutherland ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Lens Epithelial Cells ◽  
Donor Age ◽  
Rabbit Lens

Platelet Microtubule Subunit Proteins

1979 ◽  
Vol 42 (05) ◽  
pp. 1630-1633 ◽  
Author(s):  
A G Castle ◽  
N Crawford
Keyword(s):  
Epithelial Cells ◽  
Gel Electrophoresis ◽  
Blood Platelets ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Lens Epithelial Cells ◽  
Molecular Weights ◽  
Kinetics Of ◽  
Microtubular Structures

SummaryBlood platelets contain microtubule proteins (tubulin and HMWs) which can be polymerised “in vitro” to form structures which resemble the microtubules seen in the intact platelet. Platelet tubulin is composed of two non-identical subunits a and p tubulin which have molecular weights around 55,000 but can be resolved in alkaline SDS-polyacrylamide gel electrophoresis. These subunits associate as dimers with sedimentation coefficients of about 5.7 S although it is not known whether the dimer protein is a homo- or hetero-dimer. The dimer tubulin binds the anti-mitotic drug colchicine and the kinetics of this binding are similar to those reported for neurotubulins. Platelet microtubules also contain two HMW proteins which appear to be essential and integral components of the fully assembled microtubule. These proteins have molecular weights greater than 200,000 daltons. Fluorescent labelled antibodies to platelet and brain tubulins stain long filamentous microtubular structures in bovine lens epithelial cells and this pattern of staining is prevented by exposing the cells to conditions known to cause depolymerisation of cell microtubules.

scholarly journals P 229 Growth of human lens epithelial cells on the anterior lens capsule in vitro

1995 ◽  
Vol 35 ◽  
pp. S199
Author(s):  
J.H. Meyer ◽  
J. Schmidt ◽  
F. Eppinger ◽  
B. Flügel ◽  
K.U. Löffler ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Lens Capsule ◽  
Human Lens ◽  
Lens Epithelial Cells ◽  
Human Lens Epithelial Cells ◽  
Anterior Lens Capsule
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