Chondroitin synthases I, II, III and chondroitin sulfate glucuronyltransferase expression in colorectal cancer.

Glycosaminoglycans undergo significant structural alterations in cancer, namely in terms of their sulfation pattern and hydrodynamic size. Numerous studies have focused on this issue, and have demonstrated that glycosaminoglycans play a crucial role in cancer growth and invasion. However, the majority of the enzymes involved in glycosaminoglycan alterations have yet to be examined in detail. The present study focused on the expression of chondroitin-synthesizing enzymes in colorectal cancer. Specimens from healthy controls and cancer patients were subjected to RT-PCR analysis after RNA isolation, and to Western blotting after sequential extraction. The results indicated that chondroitin polymerizing factor and glucuronyltransferase gradually increased with cancer stage, and were expressed at much higher levels in adenomas compared to adjacent normal tissue. The opposite profile was obtained for chondroitin synthase I. Chondroitin synthase III was present at low levels in all the samples examined; however, its expression was higher in the samples from the cancer patients than in those from the healthy controls. It can therefore be concluded that, among the various factors regulating the structure of glycosaminoglycans in cancer, the differential expression of chondroitin-synthesizing enzymes is of the most significance.

Involvement of hyaluronidases in colorectal cancer.

BACKGROUND: Hyaluronidases belong to a class of enzymes that degrade, predominantly, hyaluronan. These enzymes are known to be involved in physiological and pathological processes, such as tumor growth, infiltration and angiogenesis, but their exact role in tumor promotion or suppression is not clear yet. Advanced colorectal cancer is associated with elevated amounts of hyaluronan of varying size. The aim of the present study was therefore to illuminate the importance of hyaluronidases in colon carcinoma progression. METHODS: The patients' samples (macroscopically normal and cancerous) were subjected to sequential extraction with PBS, 4 M GdnHCl and 4 M GdnHCl --1% Triton X-100. The presence of the various hyaluronidases in the extracts was examined by zymography and western blotting. Their expression was also examined by RT-PCR. RESULTS: Among hyaluronidases examined, Hyal-1, -2, -3 and PH-20 were detected. Their activity was higher in cancerous samples. Hyal-1 and Hyal-2 were overexpressed in cancerous samples, especially in advanced stages of cancer. Both isoforms were mainly extracted with PBS. Hyal-3 was observed only in the third extract of advanced stages of cancer. PH-20 was abundant in all three extracts of all stages of cancer. The expression of only Hyal-1 and PH-20 was verified by RT-PCR. CONCLUSION: A high association of hyaluronidases in colorectal cancer was observed. Each hyaluronidase presented different tissue distribution, which indicated the implication of certain isoforms in certain cancer stages. The results provided new evidence on the mechanisms involved in the progression of colorectal cancer.

Alterations of glycosaminoglycan disaccharide content and composition in colorectal cancer: structural and expressional studies.

The glycosaminoglycans are implicated in many processes important in the growth and progression of malignant tumors. In the present study glycosaminoglycans were purified from healthy, macroscopically normal and cancerous specimens of different anatomic sites and different stages of cancer and analyzed by FACE after chondroitinases and sulfatases digestion. The cancerous samples contained increased levels of 6-sulfated unsaturated disaccharides compared to macroscopically normal and healthy samples, the increase being stage-related. The differences in sulfation were found to be related to the anatomic site and the stage of cancer. RT-PCR analysis of 4-sulfotransferase mRNA revealed its presence in decreasing amounts as the stage of the cancer increased. Furthermore, the percent content of hyaluronan disaccharides was elevated in macroscopically normal samples compared to the cancerous, and in addition, it was much more elevated than that of healthy samples. Haluronan levels increase with stage in cancerous tissues. Therefore, it could be concluded that the glycosaminoglycans in colorectal cancer are biosynthetically directed to contribute in different ways depending on the cancer stage and anatomical site.

Keratan sulfate-containing proteoglycans in sheep brain with particular reference to phosphacan and synaptic vesicle proteoglycan isoforms.

Proteoglycans (PGs) are widely expressed in all areas of the brain. In this study, the keratan sulfate-containing PGs (KS-PGs) from cerebrum (CB), cerebellum (CL) and brainstem (BS) of young sheep brain were isolated, purified and characterized. The amount of KS-PGs in CL was significantly lower than that in CB and BS. KS-PGs were characterized by increased extent of glycosylation and heterogeneity of KS chains in CL. Western blot analyses demonstrated the presence of the KS-PGs phosphacan, SV2A and SV2B isoforms of synaptic vesicle proteoglycan in all three areas of the young sheep brain. Phosphacan predominated in BS and CB, showing significant molecular heterogeneity. SV2A and SV2B were found in two forms of high and low molecular sizes according to their extent of glycosylation in sheep brain. SV2A predominated in CL, where forms with very high molecular sizes were detected. Immunohistochemical examination revealed that SV2A was localized in the extracellular matrix of both gray and white matter. In contrast, phosphacan and SV2B were mainly localized in the white matter in all brain regions. The results of the present study demonstrated that KS-PGs are present in the three areas of the sheep brain, showing significant variations in their content, structure and localization among the distinct areas. These differences may be important for the physiology of the brain.

Hyaluronan and chondroitin sulfate proteoglycans in the supramolecular organization of the mammalian vitreous body.

The mammalian vitreous gel is a specialized type of highly hydrated extracellular matrix, which is composed of interwoven networks of uronic acid-containing polyanionic macromolecules, (i.e., hyaluronan, versican, and IX collagen) and collagen fibrils. Hyaluronan comprises the vast majority of the uronic acid-containing molecules, which contributes to structure and function of vitreous in at least two ways: its unique biophysical and hydrodynamic properties influence the vitreous homeostasis and biomechanics; it is also a template for assembly of other extracellular macromolecules, for example, versican. The other uronic acid-containing molecules namely versican and IX collagen--two chondroitin sulfate (CS) proteoglycans--occur in the vitreous without significant quantitative variations among different mammalians but with some marked variations on the molecular size and sulfation pattern of their chondroitin sulfate side chains. The contribution of versican and IX collagen (through their protein and their CS side chains) to the supramolecular organization of the vitreous gel is poorly understood. However, versican having the ability to bind hyaluronan via its N-terminal and other binding partners via its C-terminal region can play a crucial role on the structural stability and functionality of the vitreous.

Biochemical changes of extracellular proteoglycans in squamous cell laryngeal carcinoma.

Larynx is a complicated organ with peculiar properties, having a noticeable impact in vocal and respiratory physiology. In squamous cell laryngeal carcinoma, the extracellular matrix components underwent significant modifications concerning their fine chemical structure. Degradation of aggrecan is observed, whereas versican and decorin amounts are increased. The expression of aggrecan is almost totally ceased in later cancer stages, whereas decorin is expressed in normal and cancerous samples. But its expression is increased in cancer, being related to cancer stage. However, the expression of versican seems to be characteristic of the tumor, since none or traces expression is observed in normal samples. Chondroitin/dermatan sulfate is the major glycosaminoglycan, but its sulfation shows a shift from C6 position of galactosamine in normal samples to C4 in malignancy. Dermatan sulfate represents minor amounts in normal samples but increases in proportion up to one-fourth of total sulfated glycosaminoglycans in malignancy. In addition, an increase in the amounts of hyaluronan is also observed in malignant samples. Accumulated data demonstrate that tumor progression is closely related to the alteration of the expression and biochemical composition of specific extracellular constituents that describes the mild aggressive phenotype of squamous cell laryngeal carcinoma.

Plyometric exercise increases serum indices of muscle damage and collagen breakdown.

The aim of the present study was to examine the effect of acute plyometric exercise on indices of muscle damage and collagen breakdown. Nine untrained men performed an intense bout of plyometric jumping exercises (experimental group) and nine men remained at rest (control group). Seven days before and 24, 48, and 72 hours after plyometric exercise or rest, several physiological and biochemical indices of muscle damage and two biochemical indices of collagen damage were determined. No significant changes in concentric and eccentric peak torque of knee extensors and flexors or flexion and extension range of motion were found after the plyometric exercise. Delayed-onset muscle soreness increased 48 hours after exercise. Creatine kinase increased 48 and 72 hours post exercise, whereas lactate dehydrogenase increased 24, 48, and 72 hours post exercise. Serum hydroxyproline increased 24 hours post exercise, peaked at 48 hours, and remained elevated up to 72 hours post exercise. Hydroxylysine (which was measured only before exercise and at 48 hours) was found increased 48 hours post exercise. No differences were found in any physiological or biochemical index in the control group. Intense plyometric exercise increased muscle damage, delayed-onset muscle soreness, and serum indices of collagen breakdown without a concomitant decrease in the functional capacity of muscles. Hydroxyproline and hydroxylysine levels in serum seem promising measures for describing exercise-induced collagen degradation. Coaches need to keep in mind that by using plyometric activities, despite the increased muscle damage and collagen turnover that follow, it is not necessarily accompanied by decreases in skeletal muscle capacity.

Glycosaminoglycan in cerebrum, cerebellum and brainstem of young sheep brain with particular reference to compositional and structural variations of chondroitin-dermatan sulfate and hyaluronan.

Recent advances in the structural biology of chondroitin sulfate chains have suggested important biological functions in the development of the brain. Several studies have demonstrated that the composition of chondroitin sulfate chains changes with aging and normal brain maturation. In this study, we determined the concentration of all glycosaminoglycan types, i.e. chondroitin sulfate, dermatan sulfate, keratan sulfate, heparan sulfate, hyaluronan and chondroitin in cerebrum, cerebellum and brainstem of young sheep brain. In all cases, chondroitin sulfate was the predominant glycosaminoglycan type, comprising about 54-58% of total glycosaminoglycans, with hyaluronan being present also in significant amounts of about 19-28%. Of particular interest was the increased presence of the disulfated disaccharides and dermatan sulfate in cerebellum and brainstem, respectively, as well as the detectable and measurable occurrence of chondroitin in young sheep brain. Among the three brain areas, cerebrum was found to be significantly richer in chondroitin sulfate and hyaluronan, two major extracellular matrix components. These findings imply that the extracellular matrix of the cerebrum is different from those of cerebellum and brainstem, and probably this fact is related to the particular histological and functional characteristics of each anatomic area of the brain.

The structural and compositional changes of glycosaminoglycans are closely associated with tissue type in human laryngeal cancer.

Hyaluronan and sulfated glycosaminoglycans, as intrinsic components of proteoglycans, are playing important roles in cancer biology. In the present study, we investigated in detail the glycosaminoglycans on both fine chemical and structural levels in laryngeal cartilaginous and non-cartilaginous tissues at different stages of laryngeal cancer. The results indicated that in cartilaginous tissues the amounts of chondroitin sulfate, keratan sulfate, dermatan sulfate and hyaluronan presented a dramatic decrease in contrast to the non-cartilaginous tissues, which showed a significant increase of these glycosaminoglycans compared to their normal counterparts. On fine chemical structure, the molar ratios of 4-sulfated to 6-sulfated and non-sulfated to sulfated disaccharides from both cartilaginous and non-cartilaginous cancerous tissues showed a significant increase. On molecular-size level, in laryngeal cancer, the chromatographic behaviour of the sulfated glycosaminoglycan chains from both tissue-types revealed their lower M(r) with a more polydisperse and heterogeneous distribution compared to the normal ones. In addition, in both tissues, a significant decrease of high molecular-size hyaluronan was observed. Of particular interest was the great increase of hyaluronan of low molecular mass in the laryngeal non-cartilaginous tissues, which ranged from 330 to 890 kDa. The kind and the extent of these alterations, which presented an intense stage-related behaviour, depended on the tissue origin and could be associated with the malignant phenotype of human laryngeal cancer.

Chondroitin sulphate proteoglycans in the vitreous gel of sheep and goat.

In the present study, the amounts and the fine structural characteristics of chondroitin sulphate proteoglycans (CSPGs) present in sheep and goat vitreous gels were determined. The results showed that in both examined species hyaluronan was the predominant glycosaminoglycan (GAG), whereas CSPGs were present in minor amounts. CSPGs were identified as versican and collagen IX with versican being the predominant PG type. Fine structural characterization indicated that the CS chains of versican in both mammalian species were of smaller size than those found in collagen IX. The difference in the sulphation pattern of CS chains between versican and collagen IX was also of particular interest. The results indicated that the predominant disaccharide type in CS side chains of versican and collagen IX from both sheep and goat vitreous gels was the 4-sulphated disaccharide. CS chains of versican were found to be richer in 4-sulphated disaccharide units than those in collagen IX, which also contained a significant proportion of non-sulphated disaccharides. These findings showed that, firstly, the CS content and the hydrodynamic size of the CS chain and, secondly, the sulphation pattern of CS chains from versican and collagen IX in both sheep and goat vitreous gels are PG type-dependent.

The greatly increased amounts of accumulated versican and decorin with specific post-translational modifications may be closely associated with the malignant phenotype of pancreatic cancer.

Pancreatic carcinoma (PC) is a cancer type with highly malignant growth and dissemination pattern of which the mechanisms are poorly understood. However, the malignant phenotype is closely linked to extracellular matrix (ECM) of which proteoglycans (PGs) and hyaluronan (HA) play a crucial role in the control of tumor progression and metastasis. In this study, we demonstrated that versican and decorin, two different PGs with contradictory roles and functions in the pathobiology of cancer, were the main matrix PGs in PC presenting a great increase 27- and 7-fold, respectively, in comparison to normal pancreas (NP). PC was characterized by the disproportional increase of versican compared to decorin, about 4 to 1, with a concurrent increase of HA, which may be closely associated with the growth and aggressiveness of this carcinoma. Significant specific post-translational modifications were also observed in both versican and decorin regarding the type, hydrodynamic size, sulfation pattern and extent of uronate epimerization of their glycosaminoglycan chains (GAGs). In particular, chondroitin sulphate (CS) was the predominant GAG type in both PC-associated versican and decorin. The CS of PC-decorin was increased 11-fold, compared to NP in which dermatan sulfate (DS) was the predominant GAG type in both PGs. The sulfation pattern of GAG chains was significantly altered in PC, since 6-sulfated disaccharides predominated in both versican and decorin with a marked presence of non-sulfated disaccharides accompanied by lower hydrodynamic sizes of both CS and DS chains compared to NP. In conclusion, all these findings agree with the highly malignant phenotype of this cancer and, thus, more studies need to be addressed on the roles of the post-translational modifications of versican and decorin in the biology of cancer.

Cartilage aggrecan undergoes significant compositional and structural alterations during laryngeal cancer.

Aggrecan is a key component of cartilage and is responsible for the integrity and function of the tissue. In this study, the content of aggrecan and its structural modifications in adjacent to cancer apparently normal cartilages (AANCs) from various stages of laryngeal squamous cell carcinoma (LSCC) were investigated. Our data demonstrated a stage-related loss of aggregable aggrecan in AANCs, compared to the healthy laryngeal cartilage (HLC), which was excessive in advanced stages of disease. On aggregable aggrecan level, AANCs were characterized by significant compositional and structural modifications, the extent of which was closely related with the stage of LSCC. Four concrete subpopulations of aggregable molecules with particular physicochemical characteristics were identified with a strong tendency to prevail subpopulations of molecules of lower hydrodynamic sizes with increasing LSCC stage. These findings demonstrated that the cleavage of aggregable aggrecan occurred in concrete peptide bonds within the CS-1 and CS-2 attachment domains. These significant alterations were closely associated with the process of cartilage destruction, indicating the crucial role of aggrecan during LSCC.

The extractability of extracellular matrix components as a marker of cartilage remodeling in laryngeal squamous cell carcinoma.

Sequential extraction was applied to investigate the proteoglycan (PG) organization in healthy laryngeal cartilage (HLC) and laryngeal cartilage squamous cell carcinoma (LCSCC). Highly stable aggrecan aggregates, extracted from both HLC and LCSCC with strong dissociative reagents, i.e., 4 M guanidine HCl (GdnHCl), represented 53% and 7%, respectively, of total extracted macromolecules. Less stable complexes/aggregates, extracted with mild dissociative reagents (1 and 2 M GdnHCl), represented 40% and 61% of total extracted PGs from healthy and cancerous cartilage, respectively. Interestingly, a relative high proportion (32%) of uronic acid (UA)-containing macromolecules were removed from the cancerous cartilage using associative extracting solutions (PBS and 0.5 M GdnHCl), which obviously represented molecules freely extractable from the tissue. In contrast, the corresponding proportion in HLC was impressively low (about 7%). The major proportion of these molecules was chondroitin sulfate-containing PGs (CSPGs), which identified mainly as aggrecan. Differential digestion of the sequential extracts with chondroitinase ABC and chondroitinase AC II demonstrated the presence of dermatan sulfate-containing PGs (DSPGs) in both HLC and LCSCC, being mainly present in the 1 M GdnHCl extract, and identified as decorin. All cancerous extracts were found to be rich in 4-sulfated disaccharides, mostly participating in DS structures. In conclusion, the applied procedure permitted the elucidation of the changes in the cartilage status, regarding the stability and identity of its proteoglycan aggregates/complexes, in both HLC and LCSCC.

Variations in content and structure of glycosaminoglycans of the vitreous gel from different mammalian species.

The vitreous of all species is composed of essentially the same type of extracellular matrix macromolecules organized to a transparent gel. In this study, the composition and fi ne chemical structure of the glycosaminoglycans (GAGs) in the vitreous gel from sheep and goat were determined and compared with those of human and pig vitreous gels. The results showed that, in all examined species; hyaluronan (HA) was the predominant GAG, whereas chondroitin sulphate (CS) was the minor one. In the vitreous gel of the most relative species, i.e. sheep and goat, higher amounts of both of HA and CS were estimated as compared with pig and human tissues. The distribution of hydrodynamic sizes of HA and CS was significantly differed among different species. All HA preparations consisted of molecules with great variability in hydrodynamic sizes. The relative proportions of the large HA molecules (size >1.8 x 10(6) kDa) were significantly higher in sheep and goat as compared with human and pig vitreous gel. The length of CS chains was also of larger size in sheep and goat (50 and 58 kDa, respectively) than the respective chains in human and pig vitreous gel (38 and 28 kDa, respectively). The sulphation patterns of CS preparations were determined following enzymic treatments, HPLC and capillary electrophoretic analyses. The human vitreous-derived CS chains showed quite different sulphation profile than that of CS isolated from other species, since 4-sulphated disaccharides were identified as the dominant moiety. In conclusion, significant compositional and structural variations between the vitreous matrixes of different species at the GAG level were identified. The functional significance of these species-dependent variations is discussed.

Matrix proteoglycans are markedly affected in advanced laryngeal squamous cell carcinoma.

Proteoglycans (PGs) are implicated in the growth and progression of malignant tumors. In this study, we examined the concentration and localization of PGs in advanced (stage IV) laryngeal squamous cell carcinoma (LSCC) and compared with human normal larynx (HNL). LSCC and HNL sections were examined immunohistochemically with a panel of antibodies, and tissues extracts were analyzed by biochemical methods including immunoblotting and high performance liquid chromatography (HPLC). The results demonstrated significant destruction of cartilage in LSCC, which was followed by marked decrease of aggrecan and link protein. In contrast to the loss of aggrecan in LSCC, accumulation of versican and decorin was observed in the tumor-associated stroma. Biochemical analyses indicated that aggrecan, versican, decorin and biglycan comprise the vast majority of total PGs in both healthy and cancerous tissue. In LSCC the absolute amounts of KS/CS/DS-containing PGs were dramatically decreased about 18-fold in comparison to HNL. This decrease is due to the loss of aggrecan. Disaccharide analysis of CS/DSPGs from LSCC showed a significant reduction of 6-sulfated Delta-disaccharides (Deltadi-6S) with a parallel increase of 4-sulfated Delta-disaccharides (Deltadi-4S) as compared to HNL. The obtained data clearly demonstrate that tumor progression is closely related to specific alteration of matrix PGs in LSCC. The altered composition of PGs in cartilage, as well as in tumor-associated stroma, is crucial for the biological behaviour of cancer cells in the diseased tissue.

Proteoglycans in human laryngeal cartilage. Identification of proteoglycan types in successive cartilage extracts with particular reference to aggregating proteoglycans.

The content, composition and structure of proteoglycans (PGs) in adult human laryngeal cartilage (HLC) were investigated. PGs were extracted from the tissue by using two different extraction protocols. In the first protocol, PGs were extracted under dissociative conditions, 4 M guanidine HCl (GdnHCl), and in the second protocol, sequentially, with phosphate buffered saline (PBS) and solutions of increasing GdnHCl concentration (0.5, 1, 2 and 4 M). Chemical and immunological analyses of dissociate extracts (first protocol) revealed the presence of four, at least, different types of PGs. Aggrecan was the major PG, versican, decorin and biglycan being in small amounts. Galactosaminoglycan-containing PGs (GalAGPGs) represented the vast majority of total PGs present in extracts of HLC. Differential digestion with chondroitinase ABC and AC II showed that the GalAGPGs from HLC contained a significant proportion of dermatan sulphate (DS). In addition, disaccharide analysis showed that 6-sulphated disaccharides predominated in chondroitin sulphate (CS) chains. The sequential extraction (second protocol) indicated that PBS extract contained very little amount of PGs. The 0.5, 1 and 2 M GdnHCl extracts contained 6.3%, 24.5% and 15.2% of total extracted PGs, respectively. Four molar GdnHCl extracted the larger proportion, about 53%, of total PGs. This extract contained almost only proteoglycan aggregate components i.e., G1 bearing aggrecan, hyaluronan and link protein. The characterization of the aggrecan showed that it constituted a polydisperse population of monomers with an average molecular mass of 720 kDa. The glycosaminoglycans (GAGs) present were chondroitin sulphate with a M(r) of 15 kDa, and keratan sulphate (KS) with a M(r) of 10 kDa, in proportions 84% and 16%, respectively.

Altered content composition and structure of glycosaminoglycans and proteoglycans in gastric carcinoma.

Glycosaminoglycans (GAGs) in proteoglycan (PG) forms or as free GAGs are implicated in the growth and progression of malignant tumors. These macromolecules were investigated in human gastric carcinoma (HGC) and compared with those in human normal gastric mucosa (HNG). We report that HGC contained about 2-fold increased amounts of GAGs in comparison to HNG. Specifically, HGC showed 3- and 2.5-fold net increase in chondroitin sulphate (CS) and hyaluronan (HA) contents, respectively. Dermatan sulphate (DS) was slightly increased, but the amount of heparan sulphate (HS) was decreased. Of particular, interest were the quite different sulphation profiles of CS and DS chains in HGC in which, non-sulphated and 6-sulphated disaccharide units were increased 10 and 4 times, respectively, in comparison to HNG. On PG level, three different populations were identified in both HNG and HGC, being HSPGs, versican (CS/DS chains) and decorin (CS/DS chains). In HGC, the amounts of versican and decorin were significantly increased about 3- and 8-fold, respectively. These PGs were also characterized by marked decrease in hydrodynamic size and GAG content per PG molecule. Analysis of Delta-disaccharide of versican and decorin from HGC showed an increase of 6-sulphated Delta-disaccharides (Delta di-6S) and non-sulphated Delta-disaccharides (Delta di-0S) with a parallel decrease of 4-sulphated Delta-disaccharides (Delta di-4S) as compared to HNG, which closely correlated with the increase of CS content. In addition, the accumulation of core proteins of versican and decorin in HGC was also associated with many post-translational modifications, referring to the number, size, degree and patterns of sulphation and epimerization of CS/DS chains. Studies on the modified metabolism of PGs/GAGs are under progress and will help in deeper understanding of the environment in which tumor cells proliferate and invade.

Compositional and structural alterations of chondroitin and dermatan sulfates during the progression of atherosclerosis and aneurysmal dilatation of the human abdominal aorta.

Glycosaminoglycans participate in several biological functions in the arterial wall through their specific structures. They undergo specific compositional and structural modifications during the development of vascular diseases. The present study was performed to determine the variations in the concentration and the structural characteristics of galactosaminoglycans--chondroitin sulfate (CS) and dermatan sulfate (DS)--during the progression of atherosclerosis and aneurysmal dilatation of the human abdominal aorta. The concentration of CS was increased 24% (p < or = 0.05) in atherosclerotic type II aortas, but it was significantly decreased (29%, p < or = 0.05) in atherosclerotic type V aortas and aneurysmal aortas (65%, p < or = 0.01). In contrast, the concentration of DS was almost constant in all stages of arterial disease examined. Significant structural alterations were detected in the disaccharide composition of galactosaminoglycans. The ratio of 6-sulfated to 4-sulfated disaccharides was increased in atherosclerotic type II aortas (4.0 instead of 3.1 in normal aortas) due to the marked increase of CS in this tissue. This ratio was significantly decreased in atherosclerotic type V and aneurysmal aortas (2.1 and 1.6, respectively) due to the significant reduction of CS in the respective tissues. In addition, significant decrease of the oversulfated disaccharides, which are mainly located in DS chains, was recorded in atherosclerotic and aneurysmal aortas. Particularly, deltadi-di(2,6)S were decreased 32% (p < or = 0.01) and 86% (p < or = 0.01) in atherosclerotic type II and V aortas and 88% (p < or = 0.01) in aneurysm. Deltadi-di(2,4)S were increased in atherosclerotic type II aortas (21%, p < or = 0.01), but significantly decreased in atherosclerotic type V (33%, p < or = 0.01) and aneurysmal aortas (56%, p < or = 0.01). The amounts of deltadi-di(4,6)S were not markedly affected in the diseased tissues. These results suggest that the concentration of galactosaminoglycans is differentially affected during the progression of atherosclerosis. Furthermore, the development of vascular disease is associated with specific structural modifications, especially with the significant reduction of particular types of oversulfated disaccharides, which may play essential biological roles in the arterial wall.

Pig vitreous gel: macromolecular composition with particular reference to hyaluronan-binding proteoglycans.

The aim of this study was to examine the macromolecular composition of pig vitreous body with particular emphasis on hyaluronan-binding proteoglycans. The whole pig vitreous gel was found to contain 76 microg of hyaluronan-derived uronic acid, 700 microg of total protein and 150 microg of collagen per ml of gel. The contents of neutral hexoses and sialic acids were 80 and 22 microg/ml of vitreous gel, but only a minor proportion of them were found to be associated with the proteoglycan fraction. As estimated by gel chromatography on Sepharose CL-2B, hyaluronan presents a polydisperse hydrodynamic behavior with a lower molecular mass (M(r)) value of 220 kDa. The existence of low amounts of a hyaluronan-binding proteoglycan population with structural and immunological characteristics similar to a member of the hyalectan family, versican, has also been demonstrated. The concentration of this versican-like proteoglycan in whole vitreous accounts for 50 microg proteoglycan protein per ml of vitreous gel and represents a minor proportion (about 7%) of the total protein content. The proteoglycan has an average M(r) of 360 kDa and is substituted by chondroitin sulphate (CS) side chains. Study of the CS sulphation pattern showed that the chains were composed of both type 4- and 6-sulphated disaccharide units.

High-performance capillary electrophoretic analysis of hyaluronan and galactosaminoglycan-disaccharides in gastrointestinal carcinomas. Differential disaccharide composition as a possible tool-indicator for malignancies.

The glycosaminoglycans (GAGs) have documented implications for the growth and progression of malignant tumors. Gastrointestinal carcinomas (gastric, colon, rectum and pancreatic) are the most frequent malignancies occurring in human. GAGs, isolated from the tissues after digestion with papain, were analyzed by high-performance capillary electrophoresis (HPCE) following treatment with chondroitinase ABC. The composition of GAGs in disaccharides derived from the various gastrointestinal carcinomas was compared with those of normal tissues. We report that human gastrointestinal carcinomas are characterized by increased concentrations of GAGs, which have quite different disaccharide composition which, in turn, is associated with marked increase of non-sulfated (Delta(di)-nonS) and 6-sulfated (Delta(di)-mono6S) Delta-disaccharides. Particularly, a 12-51-fold increase in Delta(di)-nonS and a 3-42-fold increase in Delta(di)-mono6S content characterize these carcinomas, while the 4-sulfated units (Delta(di)-mono4S) showed a lower increase, about 0.5-1.5-fold. Moreover, the quantitation of hyaluronan (HA)-derived Delta-disaccharides (Delta(di)-nonS(HA)) also revealed a marked increase (1-12-fold) in the malignant tissues. On the other hand, the content of the chondroitinase ABC-resistant GAGs showed a low decrease, about 0.2-0.7-fold. The high amounts of hyaluronan (HA) produced by these carcinomas and the ectopic production of chondroitin sulphate (CS) proteoglycans, in which (Delta(di)-nonS) and (Delta(di)-mono6S) predominated, suggest a close relation between the content of these GAGs and the malignant phenotype, the metastatic ability and the survival time.