Results of transplantation of corneas preserved in 2.5% chondroitin sulfate

Thirty-seven corneas were transplanted after preservation in 2.5% chondroitin sulfate at 4 degrees C for 1-13 days (mean = 6.8 days) and compared with 37 corneas transplanted after preservation in M-K medium at 4 degrees C for 1-81 h (mean = 39 h). Two months after keratoplasty the mean endothelial cell loss was 6% in each group. The grafts preserved in K-Sol were significantly thinner 2 months postoperatively. There was a significant positive correlation between preservation time and endothelial cell loss in both groups, with the highest cell losses (greater than or equal to 30%) all occurring after 2 days storage in the M-K group and after 10 days storage in the K-Sol group. These results show that donor corneas should be used as early as feasible and that chondroitin-sulfate-based preservation media can be effectively used to extend donor storage time.

Biological roles of dermatan sulphate proteoglycans

Dermatan sulphate-containing proteoglycans (DS-PGs) are widely distributed in the extracellular matrix of skin, sclera, tendon, cartilage and a variety of other connective tissues. Two species of dermatan sulphate proteoglycans, called DS-PGI and DS-PGII, have recently been isolated from mature bovine articular cartilages. In their monomeric forms, both DS-PGI and DS-PGII are polydisperse, have relative molecular masses (Mr) ranging from 80K to 140K, and possess protein cores with apparent Mr values of approximately 45K. DS-PGI readily self-associates whereas DS-PGII does not. Polyclonal and monoclonal antibodies against DS-PGII do not react with DS-PGI. DS-PGI and DS-PGII appear to possess different core proteins and represent two different species of dermatan sulphate proteoglycans. DS-PGs have dramatic effects on the biological functions of cells. For example, they inhibit the capacity of fibroblasts to adhere to a fibronectin substratum. BALB/c 3T3 cells were labelled with [3H]thymidine and plated onto dishes coated with plasma fibronectin, plasma fibronectin plus chondroitin sulphate proteoglycan (CS-PG, cartilage-specific proteoglycan monomer), or plasma fibronectin plus DS-PGs. In the absence of proteoglycan, approximately 55% of the cells were attached at 1 h. In the presence of CS-PG, cell attachment was slightly decreased. In the presence of DS-PGs, the adhesion of the fibroblasts to fibronectin was essentially abolished. Similar results were obtained if a plasma fibronectin substratum was preadsorbed with the DS-PGs and the DS-PGs were left in the attachment medium.

Biosynthesis and processing of proteodermatan sulphate

The biosynthesis and processing of the small iduronic acid-rich proteodermatan sulphate (PDS) was studied in cultured human skin fibroblasts and arterial smooth muscle cells (SMC) with the aid of core-directed antibodies and various inhibitors of protein synthesis, intracellular transport, and glycosylation. Components of the linkage region became attached to the core protein most likely in a pre-Golgi compartment. Phosphorylation of PDS precursors also occurred in the endoplasmic reticulum with a minor contribution by the Golgi complex. Serine residues and the linkage region were identified as phosphorylated species in secreted PDS. Blockade of transport by monensin did not affect 6-sulphation but affected uronic acid epimerization and 4-sulphation. On relief from the monensin block, additional sulphation along the glycosaminoglycan chain was possible, whereas chain elongation was as in the continuous presence of the drug. Asparagine-bound oligosaccharides or glycosaminoglycan chains were not required for secretion of PDS or core protein. PDS from fibroblast and SMC secretions differed markedly in the composition of the glycosaminoglycan chains. No significant difference, however, was found on isoelectric focusing of core protein and after limited proteolysis of chondroitin ABC lyase-treated core protein. Tryptic and chymotryptic peptide maps of iodinated core proteins were similar.

Conjugation of oligosaccharides by reductive amination to amine modified chondroitin oligomer and γ-cyclodextrin

Carbohydrates present on cell surfaces participate in numerous biological recognition phenomena including cell-cell interactions, cancer metastasis and pathogen invasion. Therefore, synthetic carbohydrates have a potential to act as pharmaceutical substances for treatment of various pathological phenomena by inhibiting specifically the interaction between cell surface carbohydrates and their protein receptors (lectins). However, the inherently low affinity of carbohydrate-protein interactions has often been an obstacle for successful generation of carbohydrate based pharmaceuticals. Multivalent glycoconjugates, i.e. structures carrying several copies of the active carbohydrate sequence in a carrier molecule, have been constructed to overcome this problem. Here we present two novel types of multivalent carbohydrate conjugates based on chondroitin oligomer and cyclodextrin carriers. These carriers were modified to express primary amino groups, and oligosaccharides were then bound to carrier molecules by reductive amination. Multivalent conjugates were produced using the human milk type oligosaccharides LNDFH I (Lewis-b hexasaccharide), LNnT, and GlcNAcbeta1-3Galbeta1-4GlcNAcbeta1-3Galbeta1-4Glc.

Cartilage regeneration using mesenchymal stem cells and a PLGA-gelatin/chondroitin/hyaluronate hybrid scaffold

The study was to produce a novel hybrid poly-(lactic-co-glycolic acid) (PLGA)-gelatin/chondroitin/hyaluronate (PLGA-GCH) scaffold and evaluate its potentials in cartilage repair. The porous PLGA-GCH scaffold was developed to mimic the natural extra cellular matrix of cartilage. The differentiated mesenchymal stem cells (MSCs) seeded on PLGA-GCH or PLGA scaffold were incubated in vitro and showed that, compared to PLGA scaffold, the PLGA-GCH scaffold significantly augmented the proliferation of MSCs and GAG synthesis. Then autologous differentiated MSCs/PLGA-GCH was implanted to repair full-thickness cartilage defect in rabbit, while MSCs/PLGA for the contra lateral cartilage defect (n=30). Fifteen additional rabbits without treatment for defects were used as control. Histology observation showed the MSCs/PLGA-GCH repair group had better chondrocyte morphology, integration, continuous subchondral bone, and much thicker newly formed cartilage compared with MSCs/PLGA repair group 12 and 24 weeks postoperatively. There was a significant difference in histological grading score between these two groups, which both showed much better repair than control. The present study implied that the hybrid PLGA-GCH scaffold might serve as a new way to keep the differentiation of MSCs for enhancing cartilage repair.

Chondroitin O-methyl ester: an unusual substrate for chondroitin AC lyase

Chondroitin O-methyl ester was depolymerized by chondroitin AC lyase (EC 4.2.2.5) from Flavobacterium heparinum. The major product isolated from the depolymerization reaction was found to be methyl alpha-L-threo-hex-4-enopyranosyluronate-(1-->4)-2-acetamido-2-deoxy-alpha,beta-D-galactopyranoside.

Enzymatic synthesis of chondroitin and its derivatives catalyzed by hyaluronidase

The enzymatic polymerization to provide synthetic chondroitin and its derivatives is reported here, the first example of such in vitro synthesis to date. N-Acetylchondrosine (GlcAbeta(1-->3)GalNAc) oxazoline (1a) and its derivatives (1b-1f) were designed and synthesized as novel transition state analogue substrate monomers for catalysis by hyaluronidase. Hyaluronidase is a hydrolysis enzyme of chondroitin that also catalyzes the formation of repeated glycosidic bonds in in vitro synthesis, rather than in the catabolic direction. Monomers of 2-methyl (1a), 2-ethyl (1b), and 2-vinyl (1f) oxazoline derivatives were polymerized using this enzyme, via ring-opening polyaddition with total control of regioselectivity and stereochemistry. These reactions provided the corresponding synthetic chondroitin (natural type; N-acetyl, 2a) and the derivatives (unnatural type) with N-propionyl (2b) and N-acryloyl (2f) functional groups at the C2 position of all the galactosamine units, in good yields. Monomers of 2-n-propyl (1c) and 2-isopropyl (1d) oxazoline derivatives were polymerized to produce 2c and 2d in low yield. The 2-phenyl oxazoline derivative (1e) did not afford any enzyme-catalyzed products. M(n) values of 2a and 2b reached 4800 and 4000, respectively. The M(n) value of 2a corresponds to that of the naturally occurring chondroitin. Thus, hyaluronidase catalysis allows the in vitro production of not only natural type but also the formation of unnatural type chondroitins.

Fibroblasts induce heparin synthesis in chondroitin sulfate E containing human bone marrow-derived mast cells

Human bone marrow-derived mast cells (hBMMCs), differentiated in vitro in suspension culture and under the influence of human peripheral blood mononuclear cells conditioned medium (hCM), were tested for their response to recombinant human interleukin-3 (rhIL-3) and for their behavior in different microenvironments. The hBMMCs were incubated in the presence of rhIL-3 and the changes in their proliferation rate were determined. Recombinant hIL-3 induced a more than sixfold increase in 3H-thymidine uptake into the hBMMC DNA in a dose-dependent manner. Human CM used as a control for proliferation response induced a more than eightfold maximal proliferation rate increase. Rabbit anti-rhIL-3 completely inhibited hBMMC 3H-thymidine uptake induced by rhIL-3 and decreased the hCM-induced proliferation by approximately 50%. These hBMMCs were cocultured with four different mytomicin C-treated cell monolayers and assayed for phenotypic changes. After only 2 days in coculture with either embryonic mouse skin-derived fibroblasts (MESFs) or human skin-derived fibroblasts (HSFs), a marked increase in granule number and density was noted on staining with toluidine blue. Mast cells that initially stained alcian blue+/safranin- at day 0 of coculture became alcian blue+/safranin+ during the coculture period. Human BMMC proteoglycan synthesis shifted from approximately 85% chondroitin sulfate E to approximately 60% heparin within 14 to 19 days of coculture with the MESF monolayer and to approximately 50% heparin within 19 days of coculture with the HSF monolayer. None of the above-mentioned changes were noted in cocultures of hBMMCs with 3T3 cell line fibroblast monolayers or in cocultures with bovine vascular endothelium (BVE) cell monolayers. These results demonstrate microenvironmental effects exerted by the MESF and HSF monolayers on IL-3-dependent hBMMCs similar to those reported in the conversion of murine mast cell phenotype.

Presence and function of chondroitin-4-sulfate on recombinant human soluble thrombomodulin

We constructed a human soluble thrombomodulin (sTM) expression vector using the RSV promoter. Recombinant sTM (rsTM) was expressed in CHO cells and was recovered from culture medium by ion exchange chromatography. Two active fractions, designated as rsTM alpha (low salt elution) and rsTM beta (high salt elution), were detected and further purified by immunoaffinity chromatography. Purified rsTM beta contained bound chondroitin-4-sulfate as judged by HPLC detection of the chondroitinase ABC and AC I digestion product, 2-acetamido-2-deoxy-3-O-(beta-D-gluco-4-enepyranosyluronic acid)-4-O-sulfo-D-galactose. The apparent Kd values for thrombin of alpha and beta were 7.4 and 1.4 nM respectively. RsTM beta was more effective at inhibition of thrombin clotting activity and had antithrombin III-dependent anticoagulant activity which was not possessed by rsTM alpha. Both anticoagulant activities were lost after chondroitinase treatment of rsTM beta.

Synthesis of chondroitin sulfate D and heparin proteoglycans in murine lymph node-derived mast cells. The dependence on fibroblasts

Proteoglycans synthesized in cultured mast cells derived from horse serum-immunized lymph node cells were analyzed. Treatment of the 35S-proteoglycans extracted from these cells with either chondroitinase ABC or AC resulted in 95% +/- 7% and 84% +/- 7%, respectively (mean +/- S.E., n = 3), of the radioactivity associated with disaccharides eluting in the included volume of PD-10. The 35S-proteoglycans were not hydrolyzed by nitrous acid elimination treatment. The chondroitinase ABC-generated disaccharides were analyzed by aminocyano high performance liquid chromatography. 35S-Disaccharides eluted in a major peak at a retention time of 8.1 min, corresponding to the disaccharide of chondroitin 4-sulfate proteoglycan (delta Di-4S), and a second peak at 12 min, corresponding to the disaccharide of chondroitin sulfate D proteoglycan (delta Di-diSD). Further treatment with chondro-4-sulfatase did not affect the retention time of the disaccharide corresponding to delta Di-diSD whereas this peak disappeared after the digested proteoglycan was treated either by chondro-6-sulfatase or by both sulfatases. Therefore, this disaccharide was identified as chondroitin sulfate D. Quantification of the radiolabeled disaccharides showed that delta Di-diSD contributed 20% +/- 2% (n = 3) of the total sulfated disaccharides of the chondroitin sulfate of these cultured cells. The role of fibroblasts in inducing the shift of chondroitin sulfate D into heparin proteoglycan in these mast cells was also investigated by using three types of monolayers: mouse embryonic skin fibroblasts (MESF), rat embryonic skin fibroblasts (RESF), and 3T3 fibroblasts. 35S-Proteoglycans that were extracted from the lymph node-derived mast cells cultured for 30 days on MESF and on 3T3 fibroblast monolayers were 93% +/- 4% and 30% +/- 7% (n = 3) susceptible to nitrous acid elimination, respectively. No degradation by nitrous acid was observed in 35S-proteoglycans extracted from cells cultured on RESF monolayer. Since the MESF was found to be the most potent monolayer in the induction of heparin synthesis, the kinetics of changes in the synthesis of proteoglycan types were determined in lymph node-derived mast cells cultured on MESF for up to 30 days. It was found that the synthesis of chondroitin sulfate gradually declined whereas that of heparin starting between 4 and 7 days after plating gradually increased. From the 17th day on, only the synthesis of heparin was detected.

A method for the sequence analysis of dermatan sulphate

We are attempting to develop methods for the sequencing of glycosaminoglycans from their reducing end. Here we describe a procedure for the analysis of dermatan sulphate from pig skin. The glycosaminoglycan is released from its parent proteoglycan by exhaustive proteolysis by using both endo- and exo-peptidases. The amino group of the residual serine residue is conjugated with a p-hydroxyphenyl group, which in turn is iodinated with 125I (the Bolton-Hunter reagent, BHR). The ion-exchange-purified end-labelled dermatan sulphate is then degraded partially or completely by various enzymic or chemical means to yield fragments extending from the labelled serine residue to the point of cleavage. The various products are separated by gradient PAGE, detected by autoradiography and quantified by videodensitometry. Complete digestion with chondroitin ABC lyase affords the labelled fragment delta HexA-GalNAc(-SO4)-GlcA-Gal-Gal-Xyl-Ser(-BHR). The structure was confirmed by sequential degradation from the non-reducing end by chondroitin AC lyase, HgCl2, and beta-galactosidase. Periodate oxidation cleaves most of the Xyl even without treatment with alkaline phosphatase, showing that Xyl is not substituted with phosphate. Results from partial and selective periodate oxidation indicate that most of the non-sulphated IdoA residues are located towards the non-reducing end. Partial or complete digestions with testicular hyaluronidase (in the presence of an excess of beta-glucuronidase) or chondroitin AC lyase identify the positions of GlcA residues. The results confirm that HexA next to Gal is always GlcA. Moreover, GlcA is common in the first three disaccharide repeats. Results with testicular hyaluronidase indicate that the distribution of clustered GlcA-GalNAc repeats is periodic and peaks at positions 1-3, 8-9 and around 25. Although there must be chains that contain IdoA in nearly all of the available positions, regions that have not been fully processed during biosynthesis are markedly non-random.

Influence of collagen lattice on the metabolism of small proteoglycan II by cultured fibroblasts

Small dermatan sulphate proteoglycan II from cultured human skin fibroblasts interacts with type I collagen in vitro and in vivo. When fibroblasts are maintained in a type I collagen lattice the proteoglycan remains exclusively within the lattice, and its association with fibrils can be demonstrated immunocytochemically. On the basis of [35S]sulphate incorporation, small proteoglycan II comprises about 80% of total proteoglycans secreted by cells in monolayer culture. In a collagen lattice, fibroblasts down-regulate its synthesis to the level of large chondroitin sulphate/dermatan sulphate and of heparan sulphate proteoglycans, the synthesis of which remains unaffected. Compared with the product from monolayer cultures, small proteoglycan II from collagen gels contained a longer polysaccharide chain which is characterized by a larger proportion of disulphated and a smaller proportion of monosulphated glucuronic acid-containing disaccharides. The half-life varied between 60 and 110 h. It is suggested that the compositional differences between the proteoglycan from monolayer cultures and from cells in a collagen lattice are related to the slower intracellular trafficking of the proteoglycan under the latter culture conditions.

Effects of intracameral injection of viscoelastic solutions on corneal endothelium in dogs

Contact in vivo wide-field specular microscopy was performed on right eyes of 20 healthy dogs after sodium hyaluronate (1%, n = 5), sodium chondroitin sulfate (4%) and sodium hyaluronate (3%, n = 5), hydroxypropyl methylcellulose (2%, n = 5), or balanced salt solution (control, n = 5) was injected into the anterior chamber. Using computerized morphometric analysis and pachymetry, changes in endothelial cell density, cell morphologic features, and corneal thickness from baseline values were evaluated at postinjection hour (PIH) 72 and PIH 168. Changes were not seen in endothelial cell density or cell morphologic features in any treated eye. The mean corneal thickness of all treated eyes at PIH 72 increased 6%, significantly greater than that of the nontreated eyes (P = 0.03). Mean corneal thickness of treated and nontreated eyes was similar at baseline and PIH 168 in all treatment groups.

Connective-tissue macromolecules in Golgi chicken tendon organs and at their interface with muscle fibers and adjoining tendinous structures

Tendon organs from leg and forearm muscles of white leghorn chickens were examined with a library of monoclonal antibodies to determine the composition of their connective-tissue framework and the types of connective-tissue macromolecules that occur at the sites where muscle fibers attach to the receptors. The capsules of the tendon organs were positive for connective-tissue macromolecules typical of basal lamina (collagen type IV, laminin, and heparin sulfate proteoglycan) and for tenascin, collagen types III and VI, and fibronectin. Connective-tissue bundles in the lumen of a receptor reacted primarily with antibodies against collagen type I and 4-chondroitin sulfate. The narrow partitions that divide each lumen into compartments stained for collagen type III. Toward its tendinous end, a receptor made few contacts with muscle fibers. Instead, the capsule and the collagenous bundles blended gradually with the intermuscular portions of tendons. At the muscular end, the connections were more complex. Muscle fibers that attached in series to tendon organs split to produce basal lamina-covered, finger-like extensions, which were separated from each other by fissures. Tongues of connective tissue containing tenascin, collagen types I and VI, and fibronectin extended into the fissures. Distally the tongues were continuous with the tenascin in the capsule and just internal to the capsule, fibronectin and basal lamina macromolecules in the capsule, and collagen type I in the collagenous bundles. The uninterrupted presence of these macromolecules around terminating muscle fibers and in the capsule and/or the intraluminal collagen bundles suggests that muscle fibers that attach in series at the muscular end exert a force during muscular contraction on the intraluminal collagen bundles and on the receptor capsule.

Syntheses of the methyl glycosides of the repeating units of chondroitin 4- and 6-sulfate

3,4,6-Tri-O-acetyl-D-galactal was transformed into methyl 6-O-acetyl-2-azido-4-O-benzyl-2-deoxy-beta-D-galactopyranoside and its 4-O-acetyl-6-O-benzyl analogue, each of which was glycosylated with activated, O-acetylated derivatives of methyl D-glucopyranosyluronate. The resulting beta-(1----3)-linked disaccharide derivatives were each reductively N-acetylated, hydrogenolysed, O-sulfated, and saponified to afford the disodium salts of methyl 2-acetamido-2-deoxy-3-O-(beta-D-glucopyranosyluronic acid)-4-O-sulfo-beta-D-galactopyranoside and the 6-O-sulfo analogue. D-Galactal was also transformed into activated derivatives of 2-azido-3,6-di-O-benzyl-2-deoxy-D-galactopyranose and their 3,4-di-O-benzyl analogues with various substituents at O-4 and O-6. These glycosyl donors were condensed with 6-O-protected derivatives of methyl 2,3-di-O-benzyl-beta-D-glucopyranoside to give the beta-(1----4)-linked disaccharide derivatives, which were selectively deprotected, then oxidised at C-6 of the gluco unit, reductively N-acetylated, selectively deprotected, O-sulfated at C-4 or C-6 of the galacto unit, and hydrogenolysed to give the disodium salts of methyl 4-O-(2-acetamido-2-deoxy-4-O-sulfo-beta-D-galactopyranosyl)-beta-D- glucopyranosiduronic acid and the 6-O-sulfo analogue.

Partial characterization of dermatan sulfate by proton nuclear magnetic resonance spectroscopy

The degree of galactosamine N-acetylation, iduronic acid composition, and total uronic acid/hexosamine ratios of the three dermatan sulfates of human skin, DS18, DS28, and DS35 (M. O. Longas et al. (1987) Carbohydr. Res. 159, 127-136), were determined by Fourier transform, proton nuclear magnetic resonance (FT 1H NMR) spectroscopy. Analysis of DS of varying ages was conducted at 400 MHz and 60 degrees C. Chemical shifts for H-1, H-2, H-4, and H-5 of L-IdUA were independent of those for the respective protons of D-GalNAc and D-GlcUA. The resonance intensities of H-1 and acetamido methyl protons of D-GalNac did not display the expected 1:3 ratios. Therefore, their integration values were employed to estimate the percentage N-acetylation (N-CH3/3 H-1) which was corroborated chemically. The L-IdUA content, relative to total uronic acid, was calculated from signal intensities of H-1 of L-IdUA and D-GlcUA and ascertained by quantitative chemical methods. Total uronic acid/hexosamine ratios were determined from both 1H NMR spectroscopy and chemical analyses. The data show the following N-acetylation (N-CH3/3 H-1) of galactosamine in DS:DS18, 61-72% between 17 and 60 years, unaffected by senescence; DS28, 78-86% with no age-related trend; DS35, 101% at 19 years. Furthermore, in all ages investigated, the percentage (wt/wt) L-IdUA relative to total uronic acid was 42-44% for DS18 and 37-40% for DS28. At age 19 years, DS35 had a 29% (wt/wt) L-IdUA. The total uronic acid/hexosamine ratios for DS18 and DS28 varied from 1.40:1.0 to 1.70:1.0 irrespective of age.

Presence of an endo-beta-galactosidase degrading the linkage region between the chondroitin sulfate chain and core peptide of proteoglycan

Pyridylamino chondroitin sulfate, of which the reducing terminal xylose was coupled with a fluorescent 2-aminopyridine, was incubated at pH 4.0 with an extract from the mid-gut gland of Patnopecten. The high- and low-molecular-weight products were separated by ethanol precipitation, and identified by high-performance liquid chromatography analysis. The enzyme was found to expose a galactose residue at the reducing terminus of chondroitin sulfate, and also released the pyridylamino disaccharide, galactosylxylose, from the reducing terminal site of pyridylamino chondroitin sulfate. These results suggest that endo-beta-galactosidase activity, which hydrolyzes the galactosylgalactose linkage of peptidochondroitin sulfate, is present in the mid-gut gland of Patnopecten.

1H-n.m.r. investigation of naturally occurring and chemically oversulphated dermatan sulphates. Identification of minor monosaccharide residues

The 1H-n.m.r. spectra of various dermatan sulphate preparations present, besides the major signals of the basic disaccharide unit, several other minor signals. We have assigned most of them by n.m.r., using two-dimensional proton-proton double-quantum-correlation and nuclear-Overhauser-effect spectroscopy experiments. This allowed us to identify 2-O-sulphated L-iduronic acid and D-glucuronic acid residues as well as 6-sulphated N-acetylgalactosamine (presumably 4-O-sulphated as well). 2-O-Sulphated iduronic acid was present to similar extents (6-10% of total uronic acids) in pig skin dermatan sulphate and pig intestine dermatan sulphate, whereas glucuronic acid represented 17% of the uronic acid of pig skin dermatan sulphate and was virtually absent (1%) from the other preparation. 6-O-Sulphated N-acetylgalactosamine was present in minor amounts in pig intestine dermatan sulphate only. The influence of sulphation of iduronic acid units on their conformation was assessed by using chemically oversulphated pig intestine dermatan sulphate. Introduction of sulphate groups in this unit in dermatan sulphate tends to shift the conformational equilibrium towards the 1C4 conformer.

Extracellular matrix of cultured glial cells: selective expression of chondroitin 4-sulfate by type-2 astrocytes and their progenitors

We have studied the extracellular matrix composition of cultured glial cells by immunocytochemistry with different monoclonal and polyclonal antibodies. Double immunofluorescence experiments and metabolic labeling with [3H]glucosamine performed in different types of cerebellar and cortical cultures showed that bipotential progenitors for type-2 astrocytes and for oligodendrocytes (recognized by the monoclonal antibody LB1 at early stages of their development) synthesize chondroitin sulfate (CS) and deposit this proteoglycan in their extracellular matrix. The distribution of the various [3H]glucosamine-labeled glycosaminoglycans between the intracellular and the extracellular space was different. CS was present both within the cells and in the culture medium, although in different amounts. Bi-potential progenitors became also O4-positive during their development in vitro. At the stage of O4-positivity they were still stained with antibodies against CS. However, when the progenitor cells were maintained in serum-free medium and differentiated into Gal-C-positive oligodendrocytes, they became CS-negative. In the presence of fetal calf serum in the culture medium, the bipotential progenitors differentiated into GFAP-positive type-2 astrocytes. These cells still expressed CS: their Golgi area and their surface were stained with anti-CS antibodies. Staining with monoclonal antibodies specific for different types of CS (4-sulfate, 6-sulfate, and unsulfated) revealed that both bipotential progenitors and type-2 astrocytes synthesized only chondroitin 4-sulfate. Type-1 astrocytes were negative for both the polyclonal and the monoclonal anti-CS antibodies. Finally, type-2 astrocytes and their progenitors were weakly stained with anti-laminin antibodies and unstained with anti-fibronectin. Type-1 astrocytes were positive for both anti-laminin and anti-fibronectin antibodies and appeared to secrete fibronectin in the extracellular space.

Isolation and some structure analyses of a copolymeric chondroitin sulfate-dermatan sulfate proteoglycan from post-burn, human hypertrophic scar

A D-glucuronic acid rich, copolymeric chondroitin sulfate (CS)-dermatan sulfate (DS) proteoglycan (PG) from post-burn hypertrophic scar tissue (HSc) was obtained by DEAE-cellulose chromatography and differential ethanol fractionation, and further purified on a Sepharose CL-6B column. CS-DS-PG protein content was 14% (w/w). The amino-terminal amino acid sequence of the first ten residues was as follows: NH2-Asp-Glu-Ala-B-Gly-Ile-Gly-Pro-Glu-Val. This sequence is identical to that of human embryonic fibroblast cell (IMR-90) CS-DS-PG, as well as to human HSc-DS-PG. After chondroitinase ABC treatment, two peptides (Mr 22,000 and 16,000 daltons) were detected by sodium dodecyl sulfate-(polyacryl)amide gel electrophoresis (SDS-PAGE). ELISA analysis using rabbit antiserum raised against a synthetic peptide that contained 15 amino acids in the same sequence as the amino terminus of human fetal membrane PG showed significant reactivity with HSc CS-DS-PG. HSc CS-DS-PG had an apparent Mr of approximately 78,000 daltons, as determined by Sepharose CL-6B chromatography and SDS-PAGE. Alkaline borohydride treatment of CS-DS-PG liberated CS-DS glycosaminoglycan (GAG) chains having an Mr of 29,000 daltons. The conversion of xylose to xylitol indicated that the GAG chains are attached to the PG protein core at O-3 through a xylosyl-seryl linkage. CS-DS-PG also contained both N and O-linked oligosaccharides and did not aggregate with hyaluronic acid. These results, together with those reported previously, showed that HSc CS-DS-PG and DS-PG have the same A1-A15 amino acid sequence at the amino terminus but different protein cores. HSc CS-DS-PG was completely digested with chondroitinase AC and is, therefore, distinctly different from HSc DS-PG.

Proteoglycans of bovine cementum: isolation and characterization

The proteoglycans associated with the mineralized matrix of bovine cementum have been studied biochemically and their distribution within this tissue localized immunohistochemically. Both hyaluronate and proteoglycans were fractionated by DEAE-Sephacel ion-exchange chromatography. The proteoglycans eluted in three separate peaks of which two contained alkali labile protein associated with glycosaminoglycans, and one appeared as free glycosaminoglycan chains. Analysis of the glycosaminoglycans identified chondroitin sulfate as the predominant species, although minor quantities of dermatan sulfate and heparan sulfate were also identified. Agarose-acrylamide gel electrophoresis and Sepharose CL-6B molecular sieve chromatography of the proteoglycans indicated them to be smaller in size with respect to periodontal ligament and gingival proteoglycans, but similar to bone and dentine proteoglycans. Amino acid analyses indicated subtle differences between cementum and bone proteoglycans. Using a monoclonal antibody (9-A-2) which recognizes the unsaturated disaccharide of chondroitinase ACII-digested glycosaminoglycans, chondroitin sulfate was identified in the pericellular environment within the lacunae housing the cementoblasts as well as in the extracellular matrix of cementum.

Macrophage secretory products selectively stimulate dermatan sulfate proteoglycan production in cultured arterial smooth muscle cells

Arterial dermatan sulfate proteoglycan has been shown to increase with atherosclerosis progression, but factors responsible for this increase are unknown. To test the hypothesis that smooth muscle cell proteoglycan synthesis may be modified by macrophage products, pigeon arterial smooth muscle cells were exposed to the media of either cholesteryl ester-loaded pigeon peritoneal macrophages or a macrophage cell line P388D1. Proteoglycans radiolabeled with [35S]sulfate and [3H]serine were isolated from culture media and smooth muscle cells and purified following precipitation with 1-hexadecylpyridinium chloride and chromatography. Increasing concentrations of macrophage-conditioned media were associated with a dose-response increase in [35S]sulfate incorporation into secreted proteoglycans, but there was no change in cell-associated proteoglycans. Incorporation of [3H]serine into total proteoglycan core proteins was not significantly different (5.2 X 10(5) dpm and 5.5 X 10(5) disintegrations per minute (dpm) in control and conditioned media-treated cultures, respectively), but selective effects were observed on individual proteoglycan types. Twofold increases in dermatan sulfate proteoglycan and limited degradation of chondroitin sulfate proteoglycan were apparent based on core proteins separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Immunoinhibition studies indicated that interleukin-1 was involved in the modulation of proteoglycan synthesis by macrophage-conditioned media. These data provide support for the role of macrophages in alteration of the matrix proteoglycans synthesized by smooth muscle cells and provide a mechanism to account for the reported increased dermatan sulfate/chondroitin sulfate ratios in the developing atherosclerotic lesion.

Chondroitin sulfates in developing mouse tooth germs. An immunohistochemical study with monoclonal antibodies against chondroitin-4 and chondroitin-6 sulfates

The role of glycosaminoglycans and proteoglycans during ontogenesis is not known. The developing tooth offers a potentially important model for studies of structure-function relationships. In this study, we have analysed the temproal and spatial expression of chondroitins of differing sulfation patterns in embryonic molars and incisors. For this purpose, we have used monoclonal antibodies (Mabs) specific for unsulfated, 4-sulfated, and 6-sulfated forms of chondroitin in conjunction with indirect immunofluorescence or immunoperoxidase labeling. Unsulfated chondroitin was not detected in embryonic teeth. Chondroitin 4- and chondroitin 6-sulfates were present in the stellate reticulum but otherwise they were confined to the dental mesenchyme. The 3B3 and MC21C-epitope, which are markers of 6-sulfated chondroitin, were uniformly distributed in the dental mesenchyme during the bud stage; they disappeared from the dental papilla of the cusps and of the anterior region of the incisor as development proceeded. These epitopes were absent from the basement membrane and from the predentin. In the odontoblastic cell lineage, the 3B3 and MC21C-epitopes were detected only between preodontoblasts at an early stage of differentiation. The monoclonal antibody 2B6 served as a probe to localize chondroitin 4-sulfate. This glycosaminoglycan was detected as early as the dental lamina stage but its expression was restricted to the basement membrane of the teeth until the late bell stage. After the onset of cusp formation, strong staining was also observed over the occlusal region of the dental papilla while the cervical region of the dental papilla remained 2B6-negative. Incisors at the bell stage exhibited a decreasing gradient of immunostaining by 2B6 from their anterior region to their posterior end. The extracellular matrix surrounding preodontoblasts reacted with 2B6 and the predentin, produced by the odontoblasts, was also intensely labeled with this antibody. Comparison between immunostaining with 3B3 and 2B6, on consecutive sections revealed a mutually exclusive pattern of distribution of the corresponding epitopes during odontogenesis. Furthermore, in the continuously growing incisor, a striking positive correlation was found between the immunostaining patterns produced by 3B3 and MC21C and the mitotic indices along the anterior-posterior axis of the tooth. Hence, sulfation of chondroitin seems developmentally regulated. We postulate that changes in the sulfation pattern of chondroitin might play a role in ontogenesis by locally altering the functional properties of the extracellular matrix.

Identification of monoclonal antibodies that recognize novel epitopes in native chondroitin/dermatan sulfate glycosaminoglycan chains: their use in mapping functionally distinct domains of human skin

Five monoclonal antibodies (MAb), 7D4, 4C3, 6C3, 4D3, and 3C5, were produced in mice immunized with high buoyant density embryonic chick bone marrow proteoglycans (PGs) as antigen. All of these MAb recognized epitopes in native chick bone marrow and cartilage PGs which could be selectively removed by chondroitinase ABC and chondroitinase AC II, indicating that their epitopes were present in chondroitin sulfate glycosaminoglycans (GAGs). These MAb recognized epitopes present in purified cartilage PGs obtained from a wide variety of different vertebrate species. However, none of the new MAb detected epitopes in Swarm rat chondrosarcoma PG. On the basis of these results, we propose that these MAb recognize novel epitopes located in chondroitin sulfate/dermatan sulfate glycosaminoglycan (CS/DS GAG) chains, representing at least four and possibly five different structures. Immunocytochemical studies have shown that the epitopes identified by these new MAb are differentially distributed in tissues. All of these MAb immunocytochemically detected epitopes in embryonic chick cartilage and bone marrow. Three of them (4C3, 7D4, and 6C3) recognized epitopes in adult human skin. All three detected epitopes in the epidermis, one (6C3) strongly detected epitopes in the papillary dermis, and two (4C3, 7D4) detected epitopes in the reticular dermis. Immunostaining patterns in skin using the new MAb directed against native CS/DS structures were distinctly different from those obtained using MAb against the common CS isomers. The distribution of these CS epitopes in functionally distinct domains of different tissues implies that these structures have functional and biological significance.

Extracellular accumulation of small dermatan sulphate proteoglycan II by interference with the secretion-recapture pathway

Human skin fibroblasts were metabolically labelled in the presence of affinity-purified antibodies against the core protein of small dermatan sulphate proteoglycan II. The treatment resulted in a dose- and time-dependent accumulation of this proteoglycan in the culture medium, with a 2-3-fold increase found within an experimental period of 4 h. The presence of antibodies was without influence on the rate of biosynthesis of the proteoglycan. However, proteoglycan-antibody complexes were inefficiently endocytosed. Addition of unlabelled proteoglycan, which served as a competitor for uptake, similarly led to an accumulation of newly formed [35S]sulphate-labelled proteoglycans. Proteoglycan accumulation also occurred as a consequence of its binding to collagen fibrils which were physically separated from the cell layer. Together, these results establish the quantitative importance of the secretion-recapture pathway of small dermatan sulphate proteoglycan II in cultured fibroblasts.

Quantitation of hyaluronic acid and chondroitin sulphates in rabbit synovial fluid by high-performance liquid chromatography of oligosaccharides enzymatically derived thereof

A high-performance liquid chromatographic (HPLC) method for quantifying unsaturated hexasaccharide and tetrasaccharide from Streptomyces hyaluronidase enzyme digestion products of hyaluronic acid was developed using a gel-permeation column packed with a sulphated polystyrene-divinylbenzene gel. For the oligosaccharides, the separation was accomplished in less than 7 min with a detection limit of 65 ng. An unsaturated non-sulphated disaccharide prepared from hyaluronic acid (delta Di-HA) and an unsaturated sulphated disaccharide (delta Di-4S) were analyzed by a HPLC method using a combination of two different gel-permeation columns. The separation of the disaccharides required less than 17 min at a flow rate of 0.7 ml/min with detection limits of as little as 4 ng for delta Di-HA and 5 ng for delta Di-4S. Both chromatographic methods were used for assay of a major component of hyaluronic acid and trace amounts of chondroitin sulphates in rabbit synovial fluid. The resulting contents of hyaluronic acid were compared to the values of polymeric hyaluronic acid directly measured by a HPLC method using two gel-permeation columns packed with a poly(hydroxyalkyl methacrylate) gel and the amounts of hyaluronic acid converted from uronic acid content determined by a colorimetric method.

Regulated changes in chondroitin sulfation during embryogenesis: an immunohistochemical approach

Chondroitin sulfate proteoglycans, which represent the main class of nonfibrous macromolecules found in the extracellular matrix of connective tissues, have been implicated in the control of a variety of cell activities during ontogenesis. The respective contributions of the chondroitin sulfate chains and of the protein moiety of the proteoglycan in morphogenesis and cytodifferentiation are not known. In this context, monoclonal antibodies identifying specific chondroitin sulfate chains are interesting new tools. A panel of well characterized monoclonal antibodies recognizing distinct epitopes present only in chondroitin sulfate chains was used in conjunction with immunohistochemical techniques for the purpose of identifying and mapping chondroitin sulfate isoforms during development in the mouse and rat fetus. Expression of chondroitin sulfate isoforms occurred in the tissues according to specific spatio-temporal patterns, suggesting that chondroitin sulfates differing in sulfation position and degree perform distinct functions in development.

In vitro effect on Heptest of low molecular weight heparin fractions and preparations with various anti-IIa and anti-Xa activities

The Heptest heparin assay has recently been introduced, and evaluated for the laboratory monitoring of patients receiving low molecular weight heparins (LMWH). The aim of the present study was to elucidate the relative role on the Heptest assay of the anti-factors Xa and IIa activities present in the three types of compounds that possess: 1. exclusively anti-Xa activity (LF1: LMWH fractions with MW ranging from 1,200 to 4,200 D.); 2. both anti-Xa and anti-IIa activities (LF2 with MW from 4,800 to 12,000 D.); 3. exclusive anti-IIa activity (Hirudin and Dermatan Sulfate). All compounds studied demonstrated dose-dependent activities in both amidolytic and clotting assays. The LF2 in contrast to the LF1, additionally enhanced the clotting times of Heptest. This enhancement was shown to be due to the anti-Factor IIa activity of the agents. Heptest does not exclusively reflect Anti-Xa activity since it is influenced by agents containing exclusive anti-IIa activity like Hirudin and Dermatan Sulfate. At low concentrations of LF2, Heptest measures predominantly the anti-factor Xa activity while at higher concentrations it is influenced by the combined activity of anti-factor Xa and anti-factor IIa. However, Heptest sensitivity to anti-factor IIa is significantly lower than for anti-Xa activity.

The effect of dermatan sulfate on in vitro human plasma coagulation, platelet aggregation and beta TG/PF4 release

We evaluated the in vitro anticoagulant action of dermatan sulfate (DS) (aPTT, antiXa, anti-thrombin) and its effect on human platelet aggregation and beta TG/PF4 release induced by threshold doses of aggregating agents, compared with standard heparin (SH). In pooled plasma, DS prolonged aPTT much less than SH, had no measurable antiXa activity, showed an anti-thrombin activity similar to that shown by SH at a tenfold higher dilution. DS had no direct effect on human platelet aggregation and beta TG/PF4 release. Moreover it did not significantly affect platelet aggregation and release by ADP and collagen, whereas it completely inhibited platelet aggregation and beta TG/PF4 release by thrombin. These data in vitro confirm that thrombin inhibition induced by DS is accompanied by a far lesser aPTT prolongation compared to heparin, without any appreciable interference with platelet function.

Inhibition of chondroitin sulfate incorporation into human thyroglobulin by p-nitrophenyl-beta-D-xylopyranoside

Human thyroglobulin (TG) is unique among glycoproteins and TGs of other species in having a chondroitin sulfate chain. We studied the effects of p-nitrophenol-beta-D-xylopyranoside (PNXP), an inhibitor of chondroitin sulfate incorporation into core protein of proteoglycans, on the synthesis of human TG. Fragments of normal thyroid tissue from two patients were preincubated for 1 h with PNXP before adding [35S] sulfate and [3H]leucine. TG was purified by ammonium sulfate precipitation, sucrose gradient centrifugation, and CsCl equilibrium density gradient centrifugation. Chondroitin ABC lyase released 38-42% of the [35S]sulfate from control TG, synthesized in the absence of inhibitor, demonstrating the presence of chondroitin sulfate units. In the samples incubated with increasing concentrations of PNXP (0.2 and 1 mM), the fraction of [35S] sulfate released by ABC lyase decreased progressively (14-23% and 8-11%, respectively). This confirms that, as in chondroitin sulfate proteoglycans, chondroitin sulfate synthesis in TG is initiated by the transfer of a galactose unit, by galactosyltransferase, to a xylosyl-serine in the TG peptide backbone. This step is prevented by PNXP, which is a competitive acceptor of galactose. The density of TG synthesized in the presence of PNXP was determined by CsCl equilibrium density centrifugation. [3H] leucine-labeled TG from the samples incubated with PNXP was less dense than [3H]leucine-labeled TG from the control specimen. The newly synthesized TG was less dense either because of the lack of the chondroitin sulfate chain or because further processing of the TG was impaired. To differentiate these possibilities, we treated control, [3H]leucine-labeled TG with chondroitin ABC lyase and compared its density to that of [3H] leucine-labeled TG synthesized in the presence of 1 mM PNXP. The decrease in density produced by PNXP was greater than the decrease brought about by chondroitin ABC lyase (4.3-5.2 x 10(-3) and 2.4-2.8 x 10(-3) g/cm3, respectively). Therefore, the density contributed by the chondroitin chain was insufficient to account for the entire density shift seen with PNXP. We conclude that 1) chondroitin sulfate synthesis is initiated by the transfer of a galactosyl unit to xylosyl-serine in the TG peptide backbone; and 2) inhibition of this step decreases the density of TG by preventing the addition of the chondroitin chain and interfering with the further processing of TG.

A genetic defect in the biosynthesis of dermatan sulfate proteoglycan: galactosyltransferase I deficiency in fibroblasts from a patient with a progeroid syndrome

A small proteoglycan that contains only a single dermatan sulfate chain is the main proteoglycan synthesized by skin fibroblasts. Fibroblasts from a patient with progeroidal appearance and symptoms of the Ehlers-Danlos syndrome have a reduced ability of converting the core protein of this proteoglycan into a mature glycosaminoglycan chain-bearing species. This abnormality is the consequence of a deficiency in galactosyltransferase I (xylosylprotein 4-beta-galactosyltransferase; EC 2.4.1.133), which catalyzes the second glycosyl transfer reaction in the assembly of the dermatan sulfate chain. The glycosaminoglycan-free core protein secreted by the patient's fibroblasts bears an unsubstituted xylose residue. The mutant enzyme is abnormally thermolabile. Preincubation of fibroblasts at 41 degrees C leads to a further reduction in the production of mature proteoglycan and affects the capacity for glycosaminoglycan synthesis on p-nitrophenyl beta-D-xyloside more strongly in the mutant than in control cells.

A monoclonal antibody that recognizes 2,3-, 2,6-, and 4,6-disulphate ester ring substitution in pyranose-containing polysaccharides. Its production, characterization and application for the quantitation of pentosan polysulphate, dextran sulphate, glycosaminoglycan polysulphate and chondroitin sulphate E

A method is described for the preparation of a monoclonal antibody (MAb) which binds specifically to polysaccharides which contain 2,3-, 2,6- and 4,6-disulphate ester pyranose ring substitution. Such molecules include the semisynthetic heparinoids, pentosan polysulphate (PPS), dextran sulphate (DS) and glycosaminoglycan polysulphates (GAGPS), as well as the naturally occurring polysulphated polysaccharides, chondroitin sulphate E, and the 2,6-disulphated galactoses of carrageenans. The antibody (MAb 5-B-10) did not significantly cross-react with other sulphated polysaccharides such as heparin, heparan sulphate, the chondroitin sulphates, A, B, C or D, or keratan sulphate. No cross-reactivity was found with non-sulphated polysaccharides or polyanions including hyaluronic acid, xylan, or DNA. MAb 5-B-10 was characterized as IgM and kappa light chains, and was to develop an amplified enzyme-linked immunosorbent inhibition assay (ELISIA) to detect and quantitate some of the polysulphated polysaccharides in biological fluids. Using this assay, the lower limits of detection of these compounds in serum were in the order of 50 ng/ml; however 50% inhibition was obtained between 200-500 ng/ml. The intra- and inter-assay coefficients of variation for PPS were 4.2 +/- 2.8 and 16.7 +/- 13.8% respectively. The MAb 5-B-10 and the ELISIA were used to determine the levels of PPS in plasma of three healthy non-fasted volunteers for up to 120 min post-intravenous infusion (1.0 mg/kg). The results obtained compared favourably with kinetic data reported by others using a competitive binding assay method for this drug.

Conformational equilibria of the L-iduronate residue in non-sulphated di-, tetra- and hexa-saccharides and their alditols derived from dermatan sulphate

The conformation of the L-iduronate residue in non-sulphated di-, tetra- and hexa-saccharides and their alditol derivatives derived from rooster comb dermatan sulphate was investigated by 400 MHz 1H-n.m.r. spectroscopy. The ratio of conformational isomers is obtained by the average spin-spin coupling constants of a mixture of nearly isoenergetic conformers (1C4, 4C1 and 2S0). The non-reducing terminal L-iduronate residue in the tetrasaccharides (I-H-I-H and I-H-G-H) and their alditols (I-H-I-H-ol and I-H-G-H-ol) is in equilibrium with three conformers (1C4, 30%; 4C1, 40%; 2S0, 30%) of nearly equal population. Whereas the internal L-iduronate residue in the tetrasaccharides (I-H-I-H and G-H-I-H) exists as an equilibrium mixture of 1C4 (54%) and 2S0 (42-44%) conformers, that of their alditols (I-H-I-H-ol and G-H-I-H-ol) is in equilibrium between 2S0 conformer (66%) and 1C4 conformer (28%). The conformational population for the internal L-iduronate residue 2I in the hexasaccharide (3I-H-2I-H-1I-H) is also calculated and compared with that for the L-iduronate residue in native dermatan sulphate, which was calculated on the basis of the spin-spin coupling constants reported by Gatti, Casu, Torri & Vercellotti [(1979) Carbohydr. Res. 68, c3-c7].

Isolation and characterization of Patnopecten mid-gut gland endo-beta-xylosidase active on peptidochondroitin sulfate

An endo-beta-xylosidase acting on the linkage region of peptidochondroitin sulfate was isolated from the mid-gut gland of the mollusc Patnopecten and purified about 375-fold, using a combination of ammonium sulfate fractionation, gel filtration on Sephacryl S-200, and DEAE-Sephacel chromatography. The pH optimum and the isoelectric point of this enzyme were 4.0 and 7.0, respectively. The molecular weight, estimated by gel filtration through Sephacryl S-200, was 78,000. The purified enzyme was completely free from protease, exoglycosidases, sulfatase, and phosphatase. This enzyme hydrolyzed the xylosyl serine linkage of the linkage region of various glycosaminoglycans, that is chondroitin sulfate, dermatan sulfate and heparan sulfate, all possessing a very small peptide segment, but not proteoglycans. It was concluded that this endo-beta-xylosidase was involved in the catabolism of proteoglycans.

An in vitro and clinical comparison of corneal storage with chondroitin sulfate corneal storage medium with and without dextran

The safety and efficacy of 1% dextran in Chondroitin Sulfate Corneal Storage Medium (CSM) in reducing corneal swelling after 4 degrees C storage was assessed in a corneal endothelial cell culture system. No difference was found in 3H-thymidine incorporation by cells incubated in either CSM-dextran medium or CSM medium alone. Subsequently, 21 pairs of corneas, stored in either CSM or CSM-dextran from 30 to 112 hours, were transplanted into 42 eyes of 42 patients, paired by diagnostic group and procedure. All CSM grafts and 19 of 21 CSM-dextran grafts were clear at 4 months with no primary donor failures in either group. Intraoperative corneal thickness was significantly greater in the CSM group (0.82 +/- 0.07 mm) than the CSM-dextran group (0.76 +/- 0.06 mm); however, the two groups did not differ thereafter. No differences in all endothelial morphometric parameters were noted between the two groups pre- and postoperatively. Average endothelial cell loss by 4 months was 13.0 +/- 16.4% for the CSM group and 16.4 +/- 15.5% for the CSM-dextran group. The addition of dextran to CSM medium results in significant intraoperative corneal thinning without adversely affecting endothelial DNA synthesis in vitro and endothelial survival in vivo.

Pharmacologic properties of a low molecular weight dermatan sulfate: comparison with unfractionated dermatan sulfate

The anticoagulant, pharmacodynamic, and antithrombotic properties of a low molecular weight dermatan sulfate (molecular weight range 1600 to 8000, peak 4000) were compared with those of unfractionated dermatan sulfate (molecular weight range 12,000 to 45,000, peak 25,000). Anticoagulant activities were evaluated as the ability of the compounds to catalyze the inhibition of thrombin in the presence of heparin cofactor II in a purified system and to prolong the activated partial thromboplastin time or the thrombin clotting time of human and rabbit plasmas. On the basis of weight, low molecular weight dermatan sulfate was two times less potent than unfractionated dermatan sulfate. After bolus intravenous injection into rabbits, the volume of distribution of low molecular weight dermatan sulfate was 10 times larger than that of unfractionated compound, and the half-life of disappearance was two to four times longer despite a 1.4 to 2.3 times higher total clearance. The bioavailability of low molecular weight dermatan sulfate from its subcutaneous depot was 100%; it was absorbed faster from that depot than unfractionated dermatan sulfate. The antithrombotic activities of unfractionated and of low molecular weight dermatan sulfate were also examined with a Wessler-type model with tissue factor as the thrombogenic stimulus. When evaluated 3 minutes after a bolus intravenous injection, unfractionated dermatan sulfate was twice as active as low molecular weight dermatan sulfate on the basis of weight. With subcutaneous injection, 10 mg/kg of low molecular weight dermatan sulfate generated an activity in plasma equivalent to 5.6 micrograms/ml 1 hour later. This concentration was associated with a significant antithrombotic effect that lasted for less than 6 hours.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of fibroblast growth factor and chondroitin sulfate on predamaged corneal endothelium. An organ culture study

Fibroblast growth factor (FGF) and chondroitin sulfate (CDS) were used as supplements in organ culture medium to compare the regeneration ability of corneal endothelium with scattered damages. After 1 week of culturing, cell densities in both FGF-supplemented and FGF + CDS-supplemented groups were not higher than the densities of the control groups. Cells in both groups showed polymorphism. In both CDS-supplemented groups, the corneas were thinner. The cell density in the group supplemented with only CDS was higher than that of the control group, but in the CDS + FGF-supplemented group the cell density was not higher than that of the control and the morphology was even worse. Combining of FGF and CDS in culture medium appeared to be disadvantageous.

Self-aggregation of bovine skin proteodermatan sulphate promoted by removal of the three N-linked oligosaccharides

Progressive digestion of native bovine skin proteodermatan sulphate with glycopeptidase F (EC. 3.2.2.18), followed by electrophoresis and affinity-blotting with concanavalin A, demonstrated the presence of three N-linked oligosaccharide chains on the protein core. These oligosaccharides were localized to the C-terminal portion of the protein core. Proteodermatan sulphate purified after removal of the oligosaccharides exhibited an altered circular dichroism spectrum and apparently enhanced thermal stability which were explained by the finding that it had aggregated. The aggregates could be partially dissociated by urea. Aggregation could also be demonstrated without intervening preparative steps between digestion with glycopeptidase-F and electrophoresis. Oligosaccharide-free proteodermatan sulphate retained its ability to inhibit fibril formation from monomeric collagen but showed a tendency to self-aggregate in solution. These results suggest a role for the oligosaccharides of proteodermatan sulphate in maintaining the molecule in a predominantly monomeric form in the tissue, thus indirectly promoting its interaction with collagen.

Transforming growth factors-beta 1 and beta 2 induce synthesis and accumulation of hyaluronate and chondroitin sulfate in vivo

Subcutaneous implantation in rats of partially purified transforming growth factor-beta (TGF-beta) derived from bovine bone induced extensive development of connective tissue with associated edema. Subcutaneous injection of pure TGF-beta 1 or TGF-beta 2 also induced connective tissue deposition in mice and guinea pigs. Sustained release of TGF-beta 1 from mini-osmotic pumps implanted subcutaneously in mature guinea pigs promoted connective tissue deposition that encapsulated the pumps. Biochemical analyses of the connective tissue capsule demonstrated that TGF-beta 1 induced a dose-dependent accumulation of glycosaminoglycans (GAGs). The GAG/DNA ratio also increased as a function of the rate of TGF-beta 1 released, suggesting that the factor increased production of GAGs per cell. Cellulose acetate gel electrophoresis of the GAGs and hydrolysis with specific glycosidases revealed that the majority of GAGs consisted of hyaluronate and chondroitin sulfate. These results demonstrate that TGF-beta 1 and TGF-beta 2 stimulate the production of not only collagenous extracellular matrix components, but also dramatically increase the in vivo synthesis of hyaluronate and chondroitin sulfate.

In vitro mineralization of a three-dimensional collagen matrix by human dental pulp cells in the presence of chondroitin sulphate

These matrices were used as cell culture substrates to investigate the influence of extracellular molecules on mineralization. Pulp cells seeded in type I collagen or type I collagen-chondroitin-4-sulphate sponges were able to grow and were morphologically similar to cells responsible for reparative dentine formation in vivo. In sponges consisting of collagen only, the cells elaborated an abundant new matrix which became organized with time and consisted of collagen fibres surrounded by fibrillar material, but no mineralization was observed. In collagen-chondroitin sulphate sponges, cells deposited less and poorly organized matrix; in these, calcification occurred, increasing with time, and at the ultrastructural level, small needle-like crystals containing calcium and phosphorus were scattered throughout the sponge fibres. These observations suggest that chondroitin sulphate might influence in vitro calcification induced by pulp cells.

Immunologic study of artificial skin used in the treatment of thermal injuries

Artificial skin (Integra) has been developed as an effective treatment of full-thickness burns. The material consists of a bovine collagen and chondroitin-6-sulfate dermal matrix with a silicone rubber "epidermal" layer. After burn wound excision, the artificial skin is implanted. Only the temporary silicone rubber epidermal membrane is removed. The dermal collagen matrix is incorporated by the host. Serial serum samples were obtained from patients who had grafts of Integra artificial skin for the determination of the humoral immune response to Integra. Integra artificial skin presents few if any humoral immunologic problems to patients. Increased antibody activity to bovine skin collagen, bovine skin collagen with chondroitin sulfate, and human skin collagen was not considered immunologically significant.

[The therapeutic effect of a biogenic paste in experimental chronic periodontitis]

The efficacy of a biogenic paste containing calcium phosphate and chondroitin sulfate was studied in dogs with experimental chronic periodontitis. The paste exerted a therapeutic effect on the periapical inflammatory destructive foci, relieving the inflammation and stimulating the reparative processes in the bone.

Relationship between dilatation of the rat uterine cervix and a small dermatan sulfate proteoglycan

Cervical linear circumference (lo), extensibility and rate of creep, and the content and concentration of collagen and proteoglycans were determined on uterine cervices of rats at different reproductive stages. The inner circumference increased from 9 +/- 3 (SD) mm at the nongravid stage to a maximum of 41 +/- 5 mm at term; a significant drop to 23 +/- 2 mm occurred by 4 h postpartum with a further drop to 18 +/- 4 mm by 1 day postpartum. The extensibility and rate of creep reached their maxima 1 day before term and returned to the nongravid value by 1 day postpartum. The small (Mr = 95,000) type II dermatan sulfate proteoglycan, the major cervical proteoglycan, increased from 43 +/- 6 micrograms per cervix at the nongravid stage to 196 +/- 33 micrograms at term. The amount of this proteoglycan decreased significantly by 35% to 126 +/- 5 micrograms within 4 h postpartum and declined further to 79 +/- 16 micrograms by 1 day postpartum. The total cervical collagen content increased less than 2-fold during pregnancy, from 3.5 +/- 0.5 to 6.3 +/- 0.7 mg; a decline to 5.8 mg by 1 day postpartum was not significant. The ratio of small proteoglycan: collagen increased 2.5-fold between the nongravid state and term, then returned to the nongravid value by 1 day postpartum. Significant correlations were found between the lo and the amount of small proteoglycan per cervix (r = 0.86; n = 69) and between lo and the ratio of small proteoglycan:collagen (r = 0.83; n = 50) when data from every reproductive stage were combined. A mechanism is proposed whereby the interaction of the proteoglycan with collagen fibers might alter mechanical properties and contribute to cervical dilatation and its rapid reversal.

Synthesis of disaccharide fragments of dermatan sulfate

Condensation of crystalline methyl 2-azido-4,6-O-benzylidene-2-deoxy-beta-D-galactopyranoside with methyl (2,3,4-tri-O-acetyl-alpha-L-idopyranosyl bromide)uronate in dichloromethane, in the presence of silver triflate and molecular sieve, provided 54% of methyl 2-azido-4,6-O-benzylidene-2-deoxy-3-O-(methyl 2,3,4-tri-O-acetyl-alpha-L-idopyranosyluronate)-beta-D-galactopyranoside . The use of methyl (2,3,4-tri-O-acetyl-alpha-L-idopyranosyl trichloroacetimidate)uronate as glycosyl donor, in the presence of trimethylsilyl triflate, improved the yield to 68%. Regioselective opening of the benzylidene group with sodium cyanoborohydride followed successively by O-sulfation with the sulfur trioxide-trimethylamine complex, saponification, catalytic hydrogenolysis and selective N-acetylation gave the disodium salt of methyl 2-acetamido-2-deoxy-3-O-(alpha-L-idopyranosyluronic acid)-4-O-sulfo-beta-D-galactopyranoside. Condensation of methyl 2-azido-4,6-O-benzylidene-2-deoxy-beta-D-galactopyranoside with methyl (2,3,4-tri-O-acetyl-alpha-D-glucopyranosyl bromide)uronate in dichloromethane, in the presence of silver triflate and molecular sieve, gave methyl 2-azido-4,6-O-benzylidene-2-deoxy-3-O-(methyl 2,3,4-tri-O-acetyl-beta-D-glucopyranosyluronate)-beta-D-galactopryano side in 85% yield. The sequence already described then gave the disodium salt of methyl 2-acetamido-2-deoxy-3-O-(beta-D-glucopyranosyluronic acid)-4-O-sulfo-beta-D-galactopyranoside.

Interaction of tetranectin with sulphated polysaccharides and trypan blue

Tetranectin is a recently discovered plasminogen binding protein from human plasma, with a known primary structure. Its interactions with various sulphated polysaccharides and trypan blue has been investigated by crossed immunoelectrophoresis, immunosorbent assay (ELISA) and gel filtration experiments. Interaction of tetranectin with chondroitin sulphate A, B, and C, heparan sulphate and trypan blue could be demonstrated by crossed immunoelectrophoresis against monospecific rabbit anti-tetranectin. Interaction of tetranectin with fucoidan could be demonstrated by all three methods, and this interaction could be prevented by heparin and to a lesser degree by chondroitin sulphate A and C, but not by fucose. These findings, together with the recently published findings, that tetranectin is present in exocrine and endocrine glands as well as in secreting surface epithelia and mesenchyme, suggest that tetranectin, in conjunction with proteoglycans, may have a function in the packaging of granules or as a participant in exocytocic processes.

The absorption, clearance and metabolic fate of dermatan sulphate administered to man--studies using a radioiodinated derivative

An iodinated derivative of dermatan sulphate was administered by the intravenous, subcutaneous and oral routes to healthy human volunteers in conjunction with unlabelled dermatan sulphate. Following intravenous injection clearance of radiolabel and concentration as measured by competitive binding assay were highly correlated and displayed complex kinetics which were not dose-dependent. Intact 125I-dermatan sulphate was absorbed following both subcutaneous and oral administration, though there appeared to be selective uptake by the gut of a subfraction comprising the smaller or less sulphated molecules. The intact material was subsequently excreted unchanged in the urine. Degradation products of dermatan sulphate were not detected by either gel filtration or affinity chromatography on Polybrene-Sepharose at any time in either plasma or urine, indicating that administered dermatan sulphate is not catabolised by man.

Secondary structure of a core protein from pig skin proteodermatan sulfate: CD and Fourier transform IR spectroscopic studies in solution

The secondary structure of a 38 kDa core protein from pig skin proteodermatan sulfate (PDS), was investigated in solution using CD and Fourier transform (FT) ir spectroscopy. Both techniques generally have provided complementary data on the secondary structures of proteins. CD spectral analysis has shown that the core protein contains 60% beta-turn and alpha-helical structures, the rest being "unordered" structure. FT ir data do not permit calculation of quantitative contributions of substructures, at the present time, to the overall secondary structure of the core protein. CD spectrum of the intact PDS is similar to the core protein CD spectrum.