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PubMed2003

Hyaluronic acid: separation and biological implications.

Hyaluronic acid (hyaluronan) is a ubiquitous extracellular matrix component, and present at high concentrations in skin, joints and cornea. In the skin, it is synthesized primarily by dermal fibroblasts and by epidermal keratinocytes. Hyaluronic acid usually exists as a high molecular mass (600,000-1,000,000) and non-sulfated glycosaminoglycan composed of a disaccharide unit of [bond]3GlcNAc beta 1[bond]4GlcA beta 1[bond]. Hyaluronic acid has been widely used not only for osteoarthritis and ophthalmology but also for cosmetics for skin care. To examine the biological activities of hyaluronic acid, we have to accurately determine the quantity and molecular masses in biological samples. We review recent development in the analysis of hyaluronic acid having various molecular sizes using electrophoretic and chromatographic techniques. Recently, interactions between hyaluronic acid oligomers and hyaluronic acid-binding proteins have attracted the interest for understanding the biological functions. We show some interesting reports on biological interactions of hyaluronic acid and its oligomers with some proteins.

Chromatography, Liquid↗
PubMed1980

Connective tissue activation. XVIII. Stimulation of hyaluronic acid synthetase activity.

Human synovial fibroblasts synthesize hyaluronic acid, a process that can be stimulated by a number of agents. Several steps in the synthetic pathway could be the locus at which these stimulators act; the final step, promoted by hyaluronic acid synthetase, was selectd for study. Hyaluronic acid synthetase is an enzyme system that transfers monosaccharide units to nascent hyaluronic acid chains. Activities of the enzyme were determined in lysates of cultured synovial fibroblasts by measuring incorporation of 14C-UDP-glucuronic acid into hyaluronic acid. Rates of hyaluronic acid synthesis were increased by adding CTAP-I or CTAP-III, DbcAMP, or prostaglandin E2 to the cultures. In each instance, hyaluronic acid synthetase activity was enhanced in a manner comparable to that seen in hyaluronic acid synthesis. The changes in enzyme and product were observed as early as 6 hr after cultures were exposed to CTAP-III, and both indices declined when this stimulator was withdrawn for 24 hr. Although DbcAMP incrased the hyaluronic acid synthetase activity of intact fibroblasts, it had no effect on the enzyme in lysates of cells. In the cultured cells, cycloheximide reduced basal levels of synthetase activity and hyaluronic acid synthesis of hyaluronic acid may do so by inducing hyaluronic acid synthetase.

Connective Tissue↗
PubMed2005

Role of CD44 in epithelial wound repair: migration of rat hepatic stellate cells utilizes hyaluronic acid and CD44v6.

The hyaluronic acid receptor, CD44, exists as multiple splice variants that appear to have a role in migration of tumor cells. The role of this receptor and its variants in normal wound repair is poorly understood. A central feature of wound repair in the liver is activation and migration of perisinusoidal stellate cells. We have examined CD44 expression by stellate cells from normal or injured rat liver, finding that it increases with injury and involves a distinct set of CD44 splice variants. Among the latter, variants containing the v6 exon (CD44v6) are strikingly increased. Analysis of migration of primary cells on transwell filter inserts reveals that only cells isolated from injured liver are migratory. Also, they move more rapidly on hyaluronic acid than on collagen I or collagen IV. A polyclonal antibody to recombinant CD44v6 blocks migration by 50%, whereas antibody to CD44v4 has no effect. The inhibition is specific for cells migrating on hyaluronic acid and is reversed by synthetic peptide representing the N terminus of the v6 protein. In conclusion, activated stellate cells use CD44v6 and hyaluronic acid for migration. Given the evidence that migration is required for progression of injury with scar formation, blockers of CD44v6 expression or function are candidates for preventing the deleterious effects of chronic fibrosis.

Alternative Splicing↗
PubMed1992

Characterization of a bovine synovial fluid lubricating factor. III. The interaction with hyaluronic acid.

Although hyaluronate is not a boundary lubricant in cartilaginous and latex:glass bearings, a distinct interaction with purified synovial lubricating factor (PSLF) was demonstrated by three means: 1) enhancement of lubricating ability in an artificial test system; 2) viscometry; 3) electron microscopy. The interaction was of a physical rather than a specific chemical type; it varied with the degree of purification of PSLF and of hyaluronate. The interaction accounts for retention of the relatively small PSLF molecule (approximately 280 kDa) with the synovial mucin on a 0.22 microns filter. The data provide evidence that hyaluronate and PSLF act synergistically in the boundary lubricating activity of animal joints.

Animals↗
PubMedDate not supplied

Acid mucopolysaccharide metabolism in leprosy. 3. Hyaluronic acid mycobacterial growth enhancement, and growth suppression by saccharic acid and vitamin C as inhibitors of beta-glucuronidase.

A series of pilot studies are presented utilizing mouse and human infections with M. leprae and mouse infections with M. lepraemurium relating to the previously reported finding that hyaluronic acid seems to be a major nutrient substrate for these bacilli. The "feeding" of hyaluronic acid to the bacilli enhanced the growth of M. leprae in mouse abdominal walls and increased the Morphologic Index of M. lepraemurium infection. Saccharic acid, an inhibitor of beta-glucuronidase previously reported as present in these leprosy bacilli, caused marked regression of advanced M. lepraemurium infection, inhii. Ascorbic acid (vitamin C), also an inhibitor of beta-glucuronidase, given at a level of 1.5 gm/day for 4.5 months to one lepromatous patient without other treatment and for up to 24 months to four other lepromatous patients receiving DDS, was accompanied by lesion regression and changes in bacillary morphology similar to those seen in the inhibitor treated mice. If these observations are confirmed the possible use of beta-glucuronidase inhibitors as a useful adjunct to other leprosy therapy is raised as is also the likelihood of developing new therapies.

Animals↗
PubMed1995

Biotinylated hyaluronic acid as a probe for identifying hyaluronic acid-binding proteins.

The glycosaminoglycans hyaluronan (HA), heparin, and chondroitin sulfate were biotinylated using biotin-x-hydrazide (biotin-epsilon-aminocaproyl hydrozyde) in conjunction with N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide hydrochloride, an activating agent for carboxyl groups. The biotin-x-hydrazide was shown to be coupled directly to the glycosaminoglycans in enzymatic digestions and competition experiments. The biotinylated HA was shown to bind to link protein and receptor for hyaluronic acid-mediated motility, two proteins known to bind HA. The labeled HA was used as a probe to detect known HA-binding proteins in chicken cartilage extract and to identify new HA-binding motifs in the G3 domain of the proteoglycan aggrecan. The significance of the biotinylation of HA, heparin, and chondroitin sulfate A are discussed.

Binding, Competitive↗
PubMedDate not supplied

Acid mucopolysaccharide metabolism in leprosy. 2. Subcellular localization of hyaluronic acid and beta-glucuronidase in leprous infiltrates suggestive of a host-Mycobacterium leprae metabolic relationship.

Electron- and light microscopic analyses were conducted on leprosy skin biopsies relative to the origin of hyaluronic acid, which has previously been observed to be distributed inversely in ratio to the degree of cell- mediated immunity. The present study investigated the subcellular localization of hyaluronic acid and its degrading enzyme in various types of leprosy. Hyaluronic acid in some lepromatous leprosy cases was shown to be accumulated in the limiting membranes of the phagosomes of lepra cells and Myco-bacteria leprae have beta-glucuronidase which plays a role in the degradation of hyaluronic acid. Contrariwise, in tuberculoid leprosy, beta-glucuronidase was detected in the lysosomes of epithelioid cells and giant cells. This result suggests that the origin of hyaluronic acid is in histiocytes and at the same time it might suggest that M. leprae is in competition with enzymes of epithelioid cells for hyaluronic acid, whereas reduced or absent beta-glucuronidase in lepra cells enable bacilli to utilize the AMPS as a nutrient.

Acetylglucosaminidase↗
PubMed1987

Serum hyaluronic acid in patients with disseminated neoplasm.

Hyaluronic acid concentrations were measured by a laser nephelometric assay in serum samples from 50 patients with advanced disseminated neoplasm and 50 healthy controls matched for age and sex. The identity of hyaluronic acid was confirmed by a combination of electrophoretic and enzymatic techniques. The mean serum hyaluronic acid concentration for the control group was 1.09 mg/l, with a range of 0-4 mg/l. The mean concentration for patients with neoplastic disease was 10.38 mg/l, with a range of 0-100 mg/l. Sixty two per cent of the patients with disseminated neoplasm had serum hyaluronic acid concentrations above the control range. There was no correlation between the increased concentration of hyaluronic acid and tumour type, serum bilirubin, serum alkaline phosphatase, or serum urea concentrations. There was a higher incidence of hypercalcaemia in patients with increased hyaluronic acid concentrations, but the correlation between hyaluronic acid and calcium concentrations was not significant. In view of the possible role of hyaluronic acid in cellular differentiation and morphogenesis the finding of increased hyaluronic acid concentrations in patients with advanced neoplastic disease may be of fundamental importance in cancer biology.

Adult↗
PubMed1997

Electrical impedance of the cochlear implant lubricants hyaluronic acid, oxycellulose, and glycerin.

Hyaluronic acid (Healon), oxycellulose (hydroxypropyl methylcellulose), and glycerin are lubricants used in cochlear implant surgery for atraumatic deep insertion of the electrode array into the scala tympani. The electrical impedances of these three lubricants were measured to assess possible effects on intraoperative evoked response measurements, such as the electrically evoked stapedius reflex and auditory brain stem response. The impedances of hyaluronic acid, oxycellulose, and saline were very similar and independent of frequency (20 Hz to 1 MHz). Glycerin had an excessively high impedance at low frequencies. A film of hyaluronic acid or oxycellulose around the electrode array immersed in saline did not have any measurable effect on the impedance; a film of glycerin resulted in a strongly reactive polarized layer. However, neither the far-field current spread nor the impedance between stimulated electrodes was affected by any of the lubricants applied as a thin film. This suggests that none of these lubricants affect intraoperative responses, when applied as a thin film.

Cochlear Implants↗
PubMed2000

Cutaneous hypersensitivity reaction to injectable hyaluronic acid gel.

BACKGROUND: Injectable hyaluronic acid gel is a non-animal biomaterial used for soft tissue augmentation. OBJECTIVE: The dermal implantation of this naturally occurring polysaccharide is reported to be well tolerated by patients, with a longer duration in tissue than bovine collagen without any major local or systemic side effects. We report a case of an acute hypersensitivity reaction in a woman after her third injection for improvement of melolabial fold wrinkles. METHODS: An adverse granulomatous-like response to the intradermal injection of a modified hyaluronic acid gel is described. RESULTS: The patient developed indurated and erythematous papulocystic nodules in the melolabial folds bilaterally at the sites of injection. CONCLUSION: Injectable hyaluronic acid gel can be associated with severe allergic reactions and patients should be warned of this possible treatment side effect.

Acute Disease↗
PubMed1986

Somite chondrogenesis in vitro: 2. Changes in the hyaluronic acid synthesis.

The role of hyaluronic acid in limb morphogenesis (chondrogenesis) has been well defined. In the present study, we found that hyaluronic acid synthesis in somite explants steadily increased until day 6, then decreased, and inclusion of notochord did not accelerate the rate of synthesis. Analysis of hyaluronidase activity in the somite explants indicated an increase in the enzyme level in day-6 cultures. Again, inclusion of notochord did not alter this pattern. The decrease in hyaluronic acid after day 6 and the increase in sulfated proteoglycan synthesis from day 6 resemble the pattern described during limb development. Subsequent studies showed that, with time, the size of the hyaluronic acid synthesized by somites increased and, again, inclusion of notochord did not influence this pattern. The results indicate that unstimulated somites are capable of synthesizing cartilage-specific proteoglycans in a relatively restricted manner, and the inclusion of notochord resulted in accelerated synthesis of stable proteoglycan aggregates typical of differentiated chondrocytes. Metabolic events in somites related to hyaluronic acid are not influenced by the notochord.

Animals↗
PubMed1998

Changes in the expression of c-myc, RB and tyrosine-phosphorylated proteins during proliferation of NIH 3T3 cells induced by hyaluronic acid.

We have shown that hyaluronic acid stimulates the proliferation of quiescent NIH 3T3 cells. We have shown that treatment of 1 mg/ml hyaluronic acid results in increase of tyrosine phosphorylation of two proteins, MW 124 kDa and 60 kDa as detected by anti-tyrosine antibodies by Western blot analysis. Maximum phosphorylation occurred within 2 h after addition of 1 mg/ml hyaluronic acid. Stimulation of proliferation was also accompanied by increase in c-Myc protein, which was inhibited by amlloride, an inhibitor of Na+/H+ antiporter and EGTA and increase in the steady state level of pRb, the RB gene product. These results suggest that the intracellular signal transduction pathways that mediate the stimulatory effects of hyaluronic acid on cellular proliferation are similar to those of growth factors.

3T3 Cells↗
PubMedDate not supplied

Chemical modification of hyaluronic acid by carbodiimides.

Hyaluronic acid (HA) is a linear polysaccharide with repeating disaccharide units of glucuronic acid and N-acetylglucosamine and is found in the extracellular matrix of connective tissues. Reaction of high molecular weight sodium hyaluronate (NaHA, MW approximately 2 x 10(6] with EDC at pH 4.75, either in the presence or absence of a primary diamine, gave the N-acylurea and O-acylisourea as NaHA-carbodiimide adducts. None of the expected intermolecular coupling with the amine component was observed. On the basis of this new observation, this method for chemical modification of HA was used in conjunction with new synthetic carbodiimides to prepare HA derivatives bearing lipophilic, aromatic, cross-linked, and tethered functional groups. The degree of conversion to NaHA-acylurea products appears to depend upon both the characteristics of various carbodiimides and the conformational structure of NaHA.

Carbodiimides↗
PubMed1981

A method for the purification of bovine vitreous body hyaluronic acid.

Bovine vitreous body hyaluronic acid was treated with activated CH-Sepharose 4B after purification with cold 5% trichloroacetic acid. By this method a highly purified hyaluronic acid can be prepared. Contaminating serum proteins were completely removed. The remaining small amounts (0.3%) of the protein contaminants were found, by immunological methods, to be non-plasma proteins.

Animals↗