Acidic glycosaminoglycan, lipid and water contents in human coronary arterial branches

A role for proteoglycans in vascular disease

The content of proteoglycans (PGs) is low in the extracellular matrix (ECM) of vascular tissue, but increases dramatically in all phases of vascular disease. Early studies demonstrated that glycosaminoglycans (GAGs) including chondroitin sulfate (CS), dermatan sulfate (DS), keratan sulfate (KS) and heparan sulfate (HS) accumulate in vascular lesions in both humans and in animal models in areas of the vasculature that are susceptible to disease initiation (such as at branch points) and are frequently coincident with lipid deposits. Later studies showed the GAGs were covalently attached to specific types of core proteins that accumulate in vascular lesions. These molecules include versican (CSPG), biglycan and decorin (DS/CSPGs), lumican and fibromodulin (KSPGs) and perlecan (HSPG), although other types of PGs are present, but in lesser quantities. While the overall molecular design of these macromolecules is similar, there is tremendous structural diversity among the different PG families creating multiple forms that have selective roles in critical events that form the basis of vascular disease. PGs interact with a variety of different molecules involved in disease pathogenesis. For example, PGs bind and trap serum components that accumulate in vascular lesions such as lipoproteins, amyloid, calcium, and clotting factors. PGs interact with other ECM components and regulate, in part, ECM assembly and turnover. PGs interact with cells within the lesion and alter the phenotypes of both resident cells and cells that invade the lesion from the circulation. A number of therapeutic strategies have been developed to target specific PGs involved in key pathways that promote vascular disease. This review will provide a historical perspective of this field of research and then highlight some of the evidence that defines the involvement of PGs and their roles in the pathogenesis of vascular disease.

Heparan sulfate in perlecan promotes mouse atherosclerosis: roles in lipid permeability, lipid retention, and smooth muscle cell proliferation

Heparan sulfate (HS) has been proposed to be antiatherogenic through inhibition of lipoprotein retention, inflammation, and smooth muscle cell proliferation. Perlecan is the predominant HS proteoglycan in the artery wall. Here, we investigated the role of perlecan HS chains using apoE null (ApoE0) mice that were cross-bred with mice expressing HS-deficient perlecan (Hspg2(Delta3/Delta3)). Morphometry of cross-sections from aortic roots and en face preparations of whole aortas revealed a significant decrease in lesion formation in ApoE0/Hspg2(Delta3/Delta3) mice at both 15 and 33 weeks. In vitro, binding of labeled mouse triglyceride-rich lipoproteins and human LDL to total extracellular matrix, as well as to purified proteoglycans, prepared from ApoE0/Hspg2(Delta3/Delta3) smooth muscle cells was reduced. In vivo, at 20 minutes influx of human (125)I-LDL or mouse triglyceride-rich lipoproteins into the aortic wall was increased in ApoE0/Hspg2(Delta3/Delta3) mice compared to ApoE0 mice. However, at 72 hours accumulation of (125)I-LDL was similar in ApoE0/Hspg2(Delta3/Delta3) and ApoE0 mice. Immunohistochemistry of lesions from ApoE0/Hspg2(Delta3/Delta3) mice showed decreased staining for apoB and increased smooth muscle alpha-actin content, whereas accumulation of CD68-positive inflammatory cells was unchanged. We conclude that the perlecan HS chains are proatherogenic in mice, possibly through increased lipoprotein retention, altered vascular permeability, or other mechanisms. The ability of HS to inhibit smooth muscle cell growth may also influence development as well as instability of lesions.

Heparan Sulfate in Perlecan Promotes Mouse Atherosclerosis

Heparan sulfate (HS) has been proposed to be antiatherogenic through inhibition of lipoprotein retention, inflammation, and smooth muscle cell proliferation. Perlecan is the predominant HS proteoglycan in the artery wall. Here, we investigated the role of perlecan HS chains using apoE null (ApoE0) mice that were cross-bred with mice expressing HS-deficient perlecan ( Hspg2 Δ3/Δ3 ). Morphometry of cross-sections from aortic roots and en face preparations of whole aortas revealed a significant decrease in lesion formation in ApoE0/ Hspg2 Δ3/Δ3 mice at both 15 and 33 weeks. In vitro, binding of labeled mouse triglyceride-rich lipoproteins and human LDL to total extracellular matrix, as well as to purified proteoglycans, prepared from ApoE0/ Hspg2 Δ3/Δ3 smooth muscle cells was reduced. In vivo, at 20 minutes influx of human 125 I-LDL or mouse triglyceride-rich lipoproteins into the aortic wall was increased in ApoE0/ Hspg2 Δ3/Δ3 mice compared to ApoE0 mice. However, at 72 hours accumulation of 125 I-LDL was similar in ApoE0/ Hspg2 Δ3/Δ3 and ApoE0 mice. Immunohistochemistry of lesions from ApoE0/ Hspg2 Δ3/Δ3 mice showed decreased staining for apoB and increased smooth muscle α-actin content, whereas accumulation of CD68-positive inflammatory cells was unchanged. We conclude that the perlecan HS chains are proatherogenic in mice, possibly through increased lipoprotein retention, altered vascular permeability, or other mechanisms. The ability of HS to inhibit smooth muscle cell growth may also influence development as well as instability of lesions.

Reduced perlecan expression and accumulation in human carotid atherosclerotic lesions

Heparan sulfate in the extracellular matrix of the artery wall has been proposed to possess anti-atherogenic properties by interfering with lipoprotein retention, suppression of inflammation, and inhibition of smooth muscle cell growth. Previously, the amount of heparan sulfate in atherosclerotic lesions from humans and animals has been shown to be reduced but the identity or identities of the heparan sulfate molecules being down regulated in this disease are not known. In this study, atherosclerotic lesions were retrieved from 44 patients undergoing surgery for symptomatic carotid stenosis. Normal iliac arteries from organ donors were used as controls. Analysis of the specimens by gene microarray showed a selective reduction in perlecan gene expression, whereas, expression of the other heparan sulfate proteoglycans in the artery wall, agrin and collagen XVIII, remained unchanged. Expression of the large chondroitin sulfate proteoglycan, versican, also remained unchanged. Real-time PCR confirmed the decrease in perlecan gene expression and the unchanged expression of versican. The findings were supported by immunohistochemical analysis demonstrating a reduced accumulation of both perlecan core protein and heparan sulfate in carotid lesions. The study demonstrates a reduction of perlecan mRNA-expression and protein deposition in human atherosclerosis, which in part explains the low levels of heparan sulfate in this disease.

Endogenous heparin activity deficiency: the 'missing link' in atherogenesis?

This paper reviews published studies since 1995 dealing with many atherogenic mechanisms where exogenous heparin was beneficial. In these areas endogenous heparin deficiency is likely to be harmful. Mechanisms included inflammatory factors, lower endogenous plasma heparin levels, lipoprotein lipase, chemokines, APOE e4, lipoprotein(a), among others. Demonstrated reduction of heparan sulfate proteoglycans (HSPG) and of endogenous plasma heparin was reviewed.

Distribution and composition of glycosaminoglycans in the left human coronary arterial branches under myocardial bridge

The distribution and composition of glycosaminoglycans (GAGs) are reported in the anterior interventricular branch under the intermyocardial bridge (MB) and the ventricular branch without bridge, both from the left human coronary artery. Chondroitin sulfate (CS), dermatan sulfate (DS) and heparan sulfate (HS) were purified and quantified by a combination of electrophoretic migration and enzymatic degradation. The absolute amounts of GAGs in the intermyocardial bridge segment (MB) increased by 47%, when compared to the pre (PreMB) and post (PostMB) segments and the ventricular arterial branch (VB). Furthermore, the relative distribution of GAGs in the intermyocardial bridge segment differs when compared to the pre and post segments as well as in the ventricular arterial branch, due to a change in the proportion of DS and CS of 41.9 and 32.4%, compared to 36.4 and 39.7%, respectively. These findings give support to the possible involvement of GAGs in the intermyocardial bridge segment, avoiding local thrombus deposition, reducing atherosclerotic development and moreover giving protection against vessel deformation caused by the systolic pressure.

Heparan sulfate isomers in cerebral arteries of Japanese women with aging and with atherosclerosis--heparitinase and high-performance liquid chromatography determinations

Composition of heparan sulfate (HS) isomers from unaffected and atherosclerotic cerebral arteries (isolated by autopsy) of Japanese women, of various ages, was studied. HS isomers were separated as disaccharide units by high-performance liquid chromatography after degeneration with HS and heparin lyases. Heparitinase facilitated differentiation of eight unsaturated disaccharides (deltaDi-S(HS)) of vascular HS isomers. The HS isomers in the cerebral arteries consisted of approximately half the total glycosaminoglycans (GAGs). Both HS (and GAGs) tended to increase with the processes of aging but decreased with the advancing development of atherosclerosis. The HS isomers consisted of a higher proportion of non-sulfated disaccharide, about 2/3 of the total HS, followed by mono-sulfated and bis-sulfated saccharides; in addition, heparin existed, albeit in minute amounts. The proportion of deltaDi-S(HS) rich in sulfate compared with HS isomers tended to increase with aging but most decreased during formation of the atheroma. Putative functions of HS isomers in cerebral arteries are discussed, based on the characteristic distribution of HS components.

Distribution of glycosaminoglycans in the intima of human aortas: changes in atherosclerosis and diabetes mellitus

Arterial glycosaminoglycans are considered to be important in atherogenesis due to their ability to trap lipid inside the vessel wall and to influence cellular migration and proliferation. Atherosclerotic lesions have displayed an altered glycosaminoglycan content and distribution. Diabetes is a recognized risk factor for atherosclerosis, but no information is available on the arterial glycosaminoglycans in human diabetes. We examined glycosaminoglycans in normal and atherosclerotic intima of non-diabetic and Type 2 (non-insulin-dependent) diabetic patients. Intima was stripped from autopsy samples of thoracic aortas; normal and plaque areas were separated. Glycosaminoglycans were isolated by delipidation, proteolytic digestion, and precipitation and characterized by quantitation of total glycosaminoglycan and evaluation of glycosaminoglycan distribution by electrophoresis and densitometry. Results indicate a significant decrease in total glycosaminoglycan and significant changes in their distribution in atherosclerotic plaques: a relative decrease in heparan sulphate, a relative increase in dermatan sulphate and thus a decrease in the ratio of heparan sulphate to dermatan sulphate. A similar but less marked change in the ratio was found in normal intima of diabetic subjects, while in their plaques this change was more pronounced. This suggests that changes in arterial glycosaminoglycans (especially the ratio of heparan sulphate to dermatan sulphate) precede the development of lesions in diabetes and may be important in atherogenesis.

Acidic glycosaminoglycans in human atherosclerotic cerebral arterial tissues

The glycosaminoglycan (GAG) content of normal and atherosclerotic areas of cerebral arterial tissue isolated from human males was measured. The main trunk and distal branches of the arteries were obtained at autopsy on 12-89-year-old Japanese subjects. The GAG components were analysed by high-performance liquid chromatography (HPLC) after enzymatic digestion, using specific GAG lyases. Both total GAGs and water content were lower in the diseased arteries than those in the normal state. In contrast, the reverse was noted for the lipid content. The main GAG component of the normal cerebral arteries was heparan sulfates (HS), comprising half the total GAGs, followed by dermatan sulfate (DS) and chondroitin 6-sulfate (Ch-6S) constituting 1/5 to 1/9 the total GAGs. Chondroitin 4-sulfate (Ch-4S) comprised approx. 1/10 the total GAGs. Oversulfated chondroitin sulfate isomers were detected as novel peaks of the chondroitin sulfate types G, B, E and H on HPLC analysis. Small amounts of hyaluronic acid (HA) and chondroitin were also detected. The total GAG content decreased with severity of atherosclerosis. The content and proportions of HS to the total GAGs decreased remarkably, and those of Ch-4S, HA and chondroitin showed a moderate decrease. The reverse was the case for those of DS, Ch-6S and oversulfated DS and/or Ch-S. The lipid components, in particular cholesterol ester, in the diseased tissue were significantly greater than in the visibly normal parts while the opposite was the case for the water content. Thus, the GAG species and their contents in human cerebral arteries showed a characteristic distribution. As oversulfated DS and Ch-S isomers have anticoagulant and anti-atherosclerotic activities, they may play a pertinent role in the disease process.

Characterization of the products generated from oversulphated dermatan sulphate isomers with chondroitinase-B by high-performance liquid chromatography

Characterization with specific chondroitinase-B of the constituents of the unsaturated sulphated disaccharides generated from variously sulphated dermatan sulphate (DS) isomers in human kidney tissues was carried out by high-performance liquid chromatography, using a sulphonized styrene-divinylbenzene copolymer. The products derived from the variously sulphated DS isomers with the chondroitinase-B at specific unsaturated disaccharides were characterized as unsaturated mono-, di- and trisulphated disaccharides. The results suggest that chondroitinase-B converts DS isomers into unsaturated 4-sulphated disaccharide, unsaturated disulphated disaccharides types B and H (delta Di-diSB and delta Di-diSH) and unsaturated trisulphated disaccharide (delta Di-triS), which possess sulphate linkage (s) at position 4 of the galactosamine residues and, in addition, at position 6 of galactosamine and/or position 2 of iduronic acid. The delta Di-diSB, delta Di-diSH and delta Di-triS were found for the first time in human kidney tissue.

The application of chondro-2-sulfatase for identification of the products generated from chondroitin sulfate isomers by high-performance liquid chromatography

A specific chondroitin sulfate-lyase, chondro-2-sulfatase, was first used for identification of the unsaturated disaccharide constituents (delta Di-S) generated from variously sulfated chondroitin sulfate and dermatan sulfate isomers by a high-performance liquid chromatographic (HPLC) method. delta Di-S generated from oversulfated chondroitin sulfate and dermatan sulfate isomers following digestion with chondroitinases were further digested by the chondro-2-sulfatase, which led to the release of one sulfate from a specific 2-position of the uronic acid residue, as judged with the new HPLC system using a resin made from a sulfonized styrene-divinylbenzene copolymer. It was also found that the chondro-2-sulfatase digests not only delta Di-S with the structure of D-uronic acid 2 sulfate 1-3-N-acetyl-D-galactosamine but also other sulfated delta Di-S with partially the same constituents, i.e., unsaturated di-sulfated disaccharide B, unsaturated di-sulfated disaccharide D or G, and unsaturated tri-sulfated disaccharide.

Glycosaminoglycans and apolipoproteins B and A-I in human aortas. Chemical and immunological analysis of lesion-free aortas from children and adults

To study changes in the contents of plasma lipoproteins in human arteries with age and the relationship of lipoproteins with other arterial constituents, we analyzed the contents of apolipoproteins B (apo B) and A-I (apo A-I), free and esterified cholesterol, and glycosaminoglycans (GAG) in lesion-free aortic intimas of 30 children and adults. The content of apo B increased significantly with age, whereas that of apo A-I remained relatively constant. Apo B and apo A-I had significant positive correlations with the content of chondroitin sulphates A + C (CS A + C), which comprised 35% to 47% of the aortic GAG. The correlations remained significant after correction for the effect of age. Aortic apo B, but not apo A-I, also showed significant positive correlations with the contents of intimal free and esterified cholesterol. The results indicate that: considerable amounts of apo B and apo A-I can be found in lesion-free aortic intimas; there is an age-related rise in the content of apo B and a fall in the ratio of apo A-I to apo B, which are unfavorable developments in the light of current views on atherogenesis; the contents of the apolipoproteins are proportional to that of CS A + C, which might have a role in the retention of lipoproteins in the arteries.

Liquid chromatographic assay for constituent disaccharides of hyaluronic acid and chondroitin sulphate isomers

An improved high-performance liquid chromatographic (HPLC) method for unsaturated disaccharides prepared from hyaluronic acid and various chondroitin sulphate and dermatan sulphate isomers was developed, which involves an ion-exchange resin prepared from a sulphonated styrene-divinylbenzene copolymer. The retention times of the individual unsaturated disaccharides were unique and reproducible, the disaccharides appearing in the following order: unsaturated non-sulphated disaccharide derived from hyaluronic acid, then unsaturated 6-sulphated, non-sulphated and 4-sulphated disaccharides from chondroitin sulphate isomers. Unsaturated disulphated disaccharide G had a much shorter retention time than the unsaturated non-sulphated disaccharide derived from hyaluronic acid. The contents of these individual unsaturated disaccharides could be determined with similar sensitivities on the basis of their ultraviolet absorbance. Selective and unique retention times and good resolutions were found for various unsaturated disulphated and trisulphated disaccharides. The proposed method can be used to determine various chondroitin sulphate and dermatan sulphate isomers in addition to hyaluronic acid in amounts as small as 100 ng to 8 micrograms. The practicality of this method was verified by its application to the separation and determination of the different types of chondroitin sulphate and dermatan sulphate isomers derived from human arteries in the presence of appreciable amounts of hyaluronic acid.

Proteoglycan composition of rabbit arterial wall under conditions of experimentally induced atherosclerosis

The concentration and composition of proteoglycans (PG) of the neointima developed following balloon catheter removal of aortic endothelium in rabbits, were assessed. PG were extracted from the aortic intimal-medial tissues with 4 M guanidinium chloride in the presence of protease inhibitors and purified subsequently by cesium chloride gradient ultracentrifugation and fractionation by high-performance liquid chromatography (HPLC). PG so obtained was analysed for its protein, cholesterol and glycosaminoglycan (GAG) content. For the characterization of the GAG moiety, an exhaustive proteolytic digestion was done. The GAG were then recovered by ethanolic precipitation and their relative distribution was determined after a selective enzymatic digestion using specific enzymes. Results show a significant increase in the amount of PG in the areas of the injured arterial wall covered by regenerated endothelium. In addition, changes in the composition of GAG were also found in the PG isolated from experimental animals when compared to PG isolated from normal aorta. A marked increase in the content of chondroitin sulfates and dermatan sulfate of injured tissue was seen. Hyaluronic acid content also changed in response to de-endothelialization and cholesterol feeding, but only moderately. The content of heparan sulfate remained unaffected in experimental tissues. Furthermore, cholesterol feeding aggravated the injury-induced increment of GAG. These findings are consistent with previously reported morphological observations, and correlate well with reports that arterial injury and cholesterol feeding act synergistically in the evolution of the atherosclerotic lesion and provide further evidence that the interaction of lipid and PG of the arterial wall may be of particular importance to our comprehension of the pathogenesis of atherosclerosis.

Collagen types in various layers of the human aorta and their changes with the atherosclerotic process

The types of collagen components extracted from human aortas by repeated pepsin digestion were investigated by SDS-polyacrylamide gel electrophoresis (SDS-PAGE), after differential salt precipitation, cyanogen bromide (CNBr) cleavage and beta-mercaptoethanol reduction. For further extraction of collagen components, repeated pepsin digestion was carried out, and two extracts, the former and latter, were obtained. The greatest increase was seen in type V collagen followed by type III in the former extract. Type I collagen was continually extracted, so the proportion of type I to other types became greater with the number of extractions. SDS-PAGE of the residue treated with CNBr revealed that it contained the greatest amount of type I, followed by the latter extract. Type I collagen comprised approximately two-thirds of the total collagen. It was the most predominant in the intima and adventitia but was also obviously abundant in the media. The proportion of type III collagen to total collagen fell slightly with advancing atherosclerosis, since the amounts of types I and V showed some increase. A band of the alpha 3(V) chain of type V collagen in the intima was occasionally detected between the bands of the alpha 1(V) and alpha 2(V) chains. Basement membrane collagen, type IV, which was extracted predominantly from the intima and subintima, showed a heterogenous distribution as to molecular size, ranging from 50 Kd to 140 Kd. The alpha 1(IV) and alpha 2(IV) collagens were found at positions corresponding to 100 Kd and 80 Kd, respectively. The content of collagen type IV also increased with the proliferative fibrotic process. Type VI collagen was found in the intima and subintima of the human aorta at a position corresponding to an approximate molecular weight of 150 Kd, and it was reduced to fragments of 40 Kd, 45 Kd and 52 Kd.

Biochemical composition of coronary arteries in Finnish children

To study the early features of atherosclerosis, we analyzed coronary artery intima medias from 63 boys and 30 girls who were newborn to 15 years old at the time of accidental death. Fatty streaks were found in five boys and one girl and, with one exception, were not present until the second decade of life. From birth there was a continuous increase in esterified cholesterol (EC) and a two- to threefold rise in free cholesterol and phospholipid. DNA, total protein, and collagen tended to rise after the first decade. The content of hyaluronic acid remained fairly constant, but sulphated glycosaminoglycans (GAGs) rose during the second decade; the highest increases were in dermatan and chondroitin sulphates. The content of arterial EC showed significant positive correlations with those of GAGs, but associations with the contents of DNA, total protein, and collagen were not significant. As judged by the observed gradual increase in arterial EC and a change in its fatty acid composition, there is a continuous increase with age in LDL-derived EC in the arterial wall. The mechanism of this accumulation is unknown, but the findings provide circumstantial evidence to support the concept that arterial GAGs may cause retention of plasma-derived lipids, which may subsequently be altered and internalized by the intimal cells.

The effect of haemodynamic stress on the glycosaminoglycan content of blood vessel walls of experimental aneurysms and arteriovenous fistulae

The glycosaminoglycan content of experimental saccular aneurysms and arteriovenous fistulae of sheep has been measured. In the experimental aneurysm hyaluronic acid, heparan sulphate, dermatan sulphate, chondroitin sulphate and total glycosaminoglycans were all elevated above control tissue levels with increases most striking for dermatan sulphate and chondroitin sulphate. In the anastomosed vein of the arteriovenous fistulae, total glycosaminoglycans were also significantly raised but which individual glycosaminoglycans were responsible was not clearly established. In the arteries feeding the fistulae, increased chondroitin sulphate in the proximal arterial segment was the only significant change observed. The changes were attributed to altered haemodynamic stresses and are similar to those reported for animal models of hypertension and early human atherosclerosis.

Polydispersity of acidic glycosaminoglycan components in human liver and the changes at different stages in liver cirrhosis

The aim of this study was to characterize acidic glycosaminoglycan components in normal human liver and in alcoholic cirrhosis, and to determine whether the proportions of individual glycosaminoglycans change with advancing cirrhosis. Acidic glycosaminoglycans are components of extracellular matrices and consist of repeating disaccharides of hexosamine and hexuronic acid with molecular weights ranging from 5 X 10(3) to 5 X 10(4), except for hyaluronic acid, whose molecular weight ranges from 3 X 10(4) to 1.6 X 10(6). The acidic glycosaminoglycan components in normal liver and at different stages of liver cirrhosis were found to be polydisperse as to the molecular weight and the degree of sulfation. The increased content of glycosaminoglycans with advancing liver cirrhosis was related to those of heparan sulfate and dermatan sulfate components. Heparan sulfates were the most prominent components of smaller molecular weight fractions. In the normal state, moderate amounts of dermatan sulfate and the oversulfated isomer were present in intermediate molecular weight fractions, but increasing amounts of the components shifted to higher molecular weight fractions with advancing cirrhosis. A small amount of hyaluronic acid was found in higher molecular weight fractions and the amount increased at the initial stage as a reversible phenomenon. The possible roles of hepatic glycosaminoglycan components in the process of fibrosis are discussed.

Therapy of atherosclerotic arteriopathy of lower limbs. Aspects and results

As far as therapy is concerned, atherosclerotic arteriopathy may be divided into acute and chronic forms. In acute embolic forms, therapy should be surgical. Only in cases of peripheral embolism or polyembolism, and in rare cases for which vascular surgery cannot be adopted, can thrombolysis be carried out with UK. In acute thrombotic forms, therapy should be medical, because a thrombus of recent formation is rich in fibrin and may be lyzed by UK. Total recanalization takes place in 61% of cases treated, partial recanalization in 23%. Subsequently perviousness is maintained by adequate antithrombotic therapy. In chronic arteriopathy, the thrombus is lacking or almost lacking in fibrin and thrombolytic therapy is not indicated. Special therapeutic combinations are used containing platelet inhibitors (ticlopidine), antifibrin drugs (subcutaneous heparin), minor fibrinolytic agents (mesoglycan) and hemorheological drugs (pentoxyphylline). This therapy seems to give good results, as showed by the low percentage in amputation calculated on 2,565 patients treated and kept under observation for 5 years. Finally let us consider chronic progressive arteriopathy. This term indicates a very advanced stage, characterized by a gradual irreversible change for the worse leading towards gangrene. As a last resort, before amputating, a thrombolytic therapy with UK was tried to see if with strong fibrinolysis continued for 3 days amputation might be avoided. In a pilot study carried out on 12 patients, the angiographic data showed only partial lysis in small arteries or arterial branches. Clinical data showed reduction or disappearance of pain at rest in 80% of cases. In 70% of cases gangrene disappeared if it was initial and superficial, it was delimited if already in progress.

Enzymatic analysis with chondrosulfatases of constituent disaccharides of sulfated chondroitin sulfate and dermatan sulfate isomers by high-performance liquid chromatography

Various under-sulfated, monosulfated, and over-sulfated chondroitin sulfate and dermatan sulfate isomers were analyzed in terms of disaccharide units before or after desulfation with chondrosulfatases in addition to digestion with chondroitinases. The unsaturated disaccharides were separable by a high-performance liquid chromatography (HPLC) method using a resin made from a sulfonized styrene-divinylbenzene copolymer. The retention times of the parent sulfated unsaturated disaccharides and newly generated unsaturated mono- or nonsulfated disaccharides were reproducible. On desulfation of the parent sulfated unsaturated disaccharides with chondrosulfatases, almost all delta Di-S showed the same retention times as those of standard delta Di-S from known components. Following digestion of delta Di-diSB with chondro-4-sulfatase as well as delta Di-diSD or delta Di-diSG with chondro-6-sulfatase, three delta Di-monoS with the same retention time were detected with the HPLC method. These newly generated delta Di-monoS2 showed that the structure is N-acetyl-D-galactosamine, uronic acid 2-sulfate.

Distribution of acidic glycosaminoglycans, lipids and water in normal human cerebral arteries at various ages

Functional alterations in arterial acidic glycosaminoglycans (AGAG) may be related to the pathogenesis of some forms of cerebrovascular disease. We measured the AGAG, lipid and water content of human cerebral artery of 275 normal males at various ages. These measures were separately carried out in the main trunk and distal branches. The AGAG components were analyzed by an enzymatic assay method employing specific enzymes which digest AGAG to assess topographic change and aging variations. The total AGAG content was higher in the main cerebral artery than in the distal branches. The main AGAG component of the normal main cerebral artery was heparan sulfates (HS), constituting half the total AGAG, followed by moderate amounts of dermatan sulfate (DS), chondroitin-6-sulfate (C-6S) and chondroitin-4-sulfate (C-4S). Hyaluronic acid (HA) was a minor component and it was more prominent in young arteries. Heparin could be occasionally detected. With advancing age, the relative amounts of HS, HA, chondroitin and C-4S both in the main trunk and distal branches decreased but those of DS and C-6S increased. The total lipid, cholesterol ester and triglyceride content was greater in the main trunk than in the distal branches; the total lipid content increased with age. A possible function of the cerebral arterial AGAG is discussed with respect to change in lipid and water content according to topographic sites and aging.

A high-performance liquid chromatography for constituent disaccharides of chondroitin sulfate and dermatan sulfate isomers

An improved high-performance liquid chromatography for unsaturated disaccharides prepared from chondroitin sulfate and dermatan sulfate isomers was developed using an ion-exchange resin made from a sulfonized styrene-divinylbenzene copolymer. By this newly devised method, it was found that the retention times of representative unsaturated disaccharides are very unique and appear in the following order: unsaturated 6-sulfated, nonsulfated, and 4-sulfated disaccharides. The content of the individual unsaturated disaccharides could be measured at similar sensitivities with ultraviolet absorbance. Sensitive and unique retention times as well as good resolution were found for various unsaturated disulfated disaccharides. The new microassay method by HPLC can be used to determine chondroitin sulfate and dermatan sulfate isomers in amounts as small as 100 ng to 8 micrograms. The practicality of this method was verified by application to the separation and quantitation of chondroitin sulfate and dermatan sulfate isomers from human coronary arteries.