Collagenase: localization in polymorphonuclear leukocyte granules in the rabbit

Cytochemical localization of tartrate-resistant acid phosphatase, alkaline phosphatase, and nonspecific esterase in perivascular cells of cartilage canals in the developing mouse epiphysis

Cytochemical localization of tartrate-resistant acid phosphatase (TRAP), tartrate-sensitive acid phosphatases (TSAP), alkaline phosphatase, and nonspecific esterase was used to characterize perivascular cells within cartilage canals. In the distal femoral epiphyses of 5- to 7-day-old mice, three stages of canal development can be distinguished, and at each developmental stage different perivascular cells were present with morphological characteristics of degradative cells. Vacuolated cells resembling macrophages, fibroblastic cells, and chondroclasts were present adjacent to the matrix in superficial, intermediate, and deep canals, respectively. In order to characterize these perivascular cells cytochemically, nonspecific esterase and TSAP staining was used to identify macrophages, alkaline phosphatase staining was used to identify fibroblastic cells, and TRAP staining was used to identify chondroclasts. There were no cells present in the canals at any developmental stage that were positive for TSAP or strongly positive for nonspecific esterase, placing doubt on the identity of the vacuolated cells as macrophages. Alkaline phosphatase-positive perivascular cells were present in the intermediate and deep canals adjacent to matrix containing alkaline phosphatase-positive chondrocytes. These alkaline phosphatase-positive cells were found in the same location within canals as the fibroblastic cells. Tartrate-resistant acid phosphatase was localized in chondroclasts at the tips of deep canals but was not confined exclusively to chondroclasts. Except for the very early stage of canal development prior to chondrocyte hypertrophy, TRAP-positive cells were present at the tips of superficial and intermediate canals as well as at the tips of the deep canals.(ABSTRACT TRUNCATED AT 250 WORDS)

Clostridial collagenase. A chemoattractant for human neutrophils

Leukocyte chemoattractants markedly alter the morphology and membrane functions of leukocytes. Bacterial collagenase causes a change in cell shape similar to that seen with the leukocyte chemoattractant, f-Met-Leu-Phe, and also promotes capping of concanavalin A. Human neutrophils in suspension or adherent to cover glasses were exposed to clostridial collagenase (10-250 units/ml) for up to 30 min at 37 degrees C and then fixed. Collagenase (125 units/ml) caused more than 85% of PMNs to assume an asymmetric or motile morphology even in the presence of 1% gelatin or 10 mg/ml bovine serum albumin. Trypsin alone (0.01-1%) did not induce a shape change. A similar morphology was seen in some untreated PMNs (less than 5% of all cells) and is characteristic of f-Met-Leu-Phe-treated cells (more than 90%). Collagenase inhibitors (i.e., reduced glutathione, cysteine, and acid-soluble collagen), however, prevented the shape change induced by collagenase but not by f-Met-Leu-Phe. At 4 degrees C, fluorescein-Con A (20 micrograms/ml) bound uniformly to both untreated and collagenase-treated cells. Upon further incubation at 37 degrees C, Con A was internalized over the entire cell periphery of the rounded, untreated cells but on collagenase-treated PMNs was rapidly gathered into a cap overlying the uropod or protuberant region of cytoplasm where it was subsequently internalized. Checkerboard Boyden chamber assays showed clostridial collagenase to be chemokinetic and chemotactic for human PMNs. In receptor binding experiments, the clostridial collagenase preparation competed poorly with [125I]formylhexapeptide for binding to PMN formylpeptide receptors (less than 15% reduction in binding at 200 units/ml collagenase). Thus, collagenase does not seem to interact strongly with the neutrophil formylpeptide receptor and may stimulate PMN motility by interacting at an altogether different site.

The effect of tension on collagen remodelling by fibroblasts: a stereological ultrastructural study

Peak levels of collagen phagocytic activity by fibroblasts during scar maturation have been shown to coincide with a reorientation of major fibre bundles in a process analogous to Wolff's Law. This activity has been shown to increase when greater tension exists across the scar. In this study, the influences of reduced tension on collagen remodeling was studied. In two groups of five rats the right achilles tendon was either: transected at its muscle insertion or was exposed in a similar fashion but left intact. The tendon samples were retrieved five days following initial surgery with a third group of five rats serving as a source of control tendon. Relative volume of collagen phagocytosis was measured at an ultrastructural level using stereological methods. No significant influence of reduced tension on collagen phagocytosis was observed. The average relative volume of fibroblast cytoplasm was significantly increased in the transected tendon. This may represent an inductive influence of as yet undetermined nature.

Cutaneous tissue repair: basic biologic considerations. I

Wound repair of the integument is reviewed in the context of new developments in cell biology and biochemistry. Injury of the skin and concomitant blood vessel disruption lead to extravasation of blood constituents, followed by platelet aggregation and blood clotting. These events initiate inflammation and set the stage for repair processes. The macrophage plays a pivotal role in the transition between wound inflammation and repair (granulation tissue formation), since this cell both scavenges tissue debris and releases a plethora of biologically active substances that include growth factors. Although concrete evidence is lacking, growth factors are probably at least partially responsible for the angiogenesis and fibroplasia (granulation tissue) that gradually fill the wound void. If the epidermal barrier is disrupted during injury, reepithelialization begins within 24 hours and proceeds first over the margin of residual dermis and subsequently over granulation tissue. The signals for angiogenesis, fibroplasia, neomatrix formation, and reepithelialization in wound repair are not known, but a number of possibilities are discussed. Matrix remodeling is the last stage of wound repair and gradually increases the scar tensile strength to 70% to 80% of normal skin.

Ascorbic acid therapy in a thermal burn model of corneal ulceration in rabbits

We studied the effect of topical and systemic ascorbic acid on a rabbit model of corneal ulceration produced by thermal burn. Central stromal ulceration occurred in 77% to 100% of eyes in all treatment groups. The rate of ulceration was accelerated in animals treated with systemic ascorbic acid. Ulceration began after 5.80 +/- 2.14 days in control eyes and 2.75 +/- 1.26 days in the eyes of rabbits treated with both topical and systemic ascorbic acid (P less than .02). Subconjunctival ascorbic acid alone did not affect the rate of ulceration (average onset, 6 +/- 1 days). Once ulceration occurred in animals treated with both topical and systemic ascorbic acid, the incidence of perforation and descemetocele formation was increased and that of healing was decreased. The time required for healing was not significantly altered by treatment (9.50 +/- 2.28 days for control eyes vs 5.75 +/- 2.78 days for treated eyes) (P greater than .05).

Increased collagenolytic activity in severed and sutured tendons following topical application of exogenous collagen in chickens

To verify the role of collagenase in reduction of peritendinous adhesion by topical application of exogenous collagen, the flexor tendons of 30 chickens were severed and sutured. Exogenous, native enriched collagen solution (ECS) was introduced in the tendon sheath via a polyethylene catheter. The effect of ECS on collagenolytic activity in the healing tendon was assessed 1, 2, and 3 weeks later both by determining the relative amounts of dialyzable protein and hydroxyproline and by using the collagen film collagenase assay. The results obtained indicated a significant increase in both dialyzable hydroxyproline level and collagenolytic activity in the ECS-treated tendons as compared with the untreated controls. It is suggested that the effect of the topically applied exogenous collagen on increasing the collagenolytic activity may be directly related to previously observed increased gliding capacity of the tendons in the same experimental model.

Serum albumin, serum antiproteases and polymorphonuclear leucocyte neutral collagenolytic protease in the tear fluid of patients with corneal ulcers

Using a micro-electroimmune assay, the concentration of polymorphonuclear leucocyte neutral collagenolytic protease, serum-albumin, alpha-1-antitrypsin and alpha-2-macroglobulin were measured in the tear fluid from 18 eyes of 16 patients with severe, melting corneal ulcers. By this method, PML-c-ase was the first time detected in tear fluid. All proteins normalized during healing of the ulcer. The findings are indicative of an important role for PML-proteases in the degradation of the corneal stroma, and of a regulative effect of the serum antiproteases leaking into the tear fluid from inflamed conjunctival vessels.

Prednisolone inhibits phagocytosis by polymorphonuclear leucocytes via steroid receptor mediated events

Prednisolone, at concentrations between 2.78 x 10(-6) M (1 mug/ml) and 1.39 x 10(-8) M (5 x 10(-3) mug/ml) exerts an inhibitory effect on the phagocytosis of latex particles by normal human polymorphonuclear leucocytes in vitro as assessed by electron microscopical analysis. This inhibition appears to be receptor-mediated, as it is dependent upon RNA and protein synthesis and is glucocorticoid specific.

Effects of beta-aminopropionitrile after posterior penetrating injury in the rabbit

Beta-aminopropionitrile, an inhibitor of collagen cross-linking, effectively limited the degree of posttraumatic vitreous proliferation in rabbits three weeks after double perforating injury. Light microscopic examination of the sites of perforating injury after five weeks showed minimal intravitreal fibrous proliferation in treated animals. Electron micrographs of the cicatricial vitreous collagen showed fragmentation of collagen into smaller fibrils and disintegration into amorphous areas. Inhibition of collagen cross-linking may undermine the strength of the vitreous scaffold by making vitreous and cicatricial collagen more sensitive to tissue collagenases produced during inflammation. The failure of fibrovascular membranes to grow into the vitreous may be a secondary effect of weakened vitreous support.

Ultrastructural quantitation of connective tissue changes in phenytoin-induced gingival overgrowth in the ferret

The gingival overgrowth obtained after maintaining ferrets on PHT appeared to be due entirely to the effect of the drug, for inflammation induced by banding had no influence on the action of PHT in eliciting the overgrowth. The significant change observed was an increase in relative volume of interstitial material (ground substance) in response to PHT. Although there was no appreciable alteration in numbers of cells present in the lesion, PHT had a significant effect on the ultrastructure of fibroblasts. These cells showed a decrease in the relative volume of phagosomes, although organelles concerned with synthesis (the rough endoplasmic reticulum and Golgi zones) were not affected. This suggests that the relative increase in ground substance may reflect decreased breakdown of extracellular material within fibroblasts, while synthetic activity is maintained at a constant level. As a consequence, there is an increase in connective tissue volume--an increase which is manifested as an overgrowth.

Purification and characterisation of an 'elastase-like' enzyme from rabbit polymorphonuclear leucocytes

An enzyme with proteolytic activity has been isolated from the subcellular granules of rabbit polymorphonuclear leucocytes. Purification of the enzyme involved extraction of the granule membranes with 0.01 M sodium phosphate buffer, pH 7.4, containing 1 M NaCl and 0.1% Triton X-100, followed by gel exclusion chromatography on Sephadex G-75. The enzyme hydrolysed p-nitrophenol-N-tert-butyloxylcarbonyl-L-alaninate, a synthetic substrate for elastase, but failed to hydrolyse elastin. The enzyme also hydrolysed azo-albumin with a pH optimum between 7.5 and 8.5. Inhibition studies indicated that the enzyme was a serine proteinase (EC 3.4.21.-) and it was found to have an apparent molecular weight of 25 000 by polyacrylamide gel electrophoresis. The purified enzyme behaved as a single on SDS-polyacrylamide gel electrophoresis, had a single isolectric point at pH 5.9, yet showed multiple components on centrifugation.

Collagenase in the human periodontal ligament

Collagenase activity was demonstrated by direct incubation to be present in human periodontal ligament. This activity was found in only one of two populations of ligament, i.e., those ligaments taken from teeth in which their attachment site was at least 2.5 mm apical to the cementoenamel junction. The collagenase was demonstrated to be of host origin because it degraded collagen into 3/4 and 1/4 alpha chain fragments characteristic of mammalian collagenases. The enzyme was shown to be inhibited in the presence of EDTA and to have a pH optimum of 7.5.

Tissue adhesive arrests stromal melting in the human cornea

The direct early application of cyanoacrylate adhesive to a prepared ulcer bed and adjacent basement membrane, followed by placement of a bandage lens, gave good results in ten patients with corneal ulceration. The patients had ulceration with keratitis sicca, herpes keratitis, and other surface diseases. Progressive melting was arrested in all cases, and concurrent adjunctive therapies were used as indicated. The technique is quick and simple.

The immunopathology of Mooren's ulcer

In a 42-year-old man with bilateral severe Mooren's ulcers, results of immunologic studies were normal, with the exception of an in vitro blastogenic response of the patient's lymphocytes to corneal stroma. The histologic studies revealed vast numbers of vacuolated neutrophils with intracytoplasmic phagosomes in and about the ulcerating cornea. Although the progression of ulceration was initially unaltered by surgical and pharmacologic trials, systemic immunosuppression with methotrexate may have prevented ulceration of the lamellar tectonic graft.

Pathogenesis of chronic inflammation in experimental ferritin-induced arthritis. IV. Immuno-electron microscopic techniques in the study of articular collagenous tissues

The earliest and most severe changes in articular collagenous tissues (ACT) occur within 24 hours of antigen challenge and are associated with and are possibly secondary to maximal immune complex deposition in ACT surfaces. The immuno-electron microscopic (immuno-em) staining characterizes the ferritin as aggregates with antibody and suggests its occurrence and deposition as a preformed immune complex. These data indicate a direct interaction between immune complexes and collagenous matrix which could relate to both antigen persistence and chronicity of the immune response. The changes described in this model have features in common with rheumatoid disease and suggest the potential for similar mechanisms of cartilage degradation.

Effect of collagen crosslinking on the rate of resorption of implanted collagen tubing in rabbits

Collagen tubes were tanned with glutaraldehyde for different periods of time. Some were oxidized with periodate and sterilized with either 60Co (1.5 Mrad) or propylene oxide. The tubes were coated with polyfilamentous polyester fabric, filled with x-ray contrast material, and implanted subcutaneously in rats and rabbits. Rate of resorption was ascertained by x-ray procedure of progressive leakage of contrast material. A close relation between tanning time of the collagen fabric-combined prostheses and rate of their resorption in subcutis was found in both rats and rabbits. In rabbits, however, the implants were resorbed at a significantly faster rate than in rats. No effect of oxidation of collagen on the resorption was observed. Collagen tubes tanned for shorter time periods and sterilized with propylene oxide were more resistant to degradation than those sterilized with irradiation. This difference was absent, however, with material tanned for longer times. The mechanism of resorption of implanted collagen tubes was studied by morphological methods. The role of inflammatory cells in resorption is documented. The paper indicates the advantages as well as limits of the x-ray method of studying the resorption rate of biodegradable materials.

A specific collagenase from rabbit fibroblasts in monolayer culture

1. Explants of rabbit skin and synovium in tissue culture secreted a specific collagenase into their culture media. Primary cultures of fibroblast-like cells, which were obtained from these tissues and maintained in culture for up to 14 subculture passages, also secreted high activities of a specific collagenase into serum-free culture medium. Secretion of enzyme activity from the cell monolayer was at constant rate for over 100h and continued for up to 8 days in serum-free culture medium. The enzymic activity released was proportional to the number of cells in the monolayer. 2. The fibroblast collagenase was maximally active between pH7 and 8. At 24 degrees C the collagenase decreased the viscosity of collagen in solution by 60%. The collagen molecule was cleaved into three-quarters and one-quarter length fragments as demonstrated by electron microscopy of segment-long-spacing crystallites (measured as native collagen molecules aligned with N-termini together along the long axis), and by polyacrylamide-gel electrophoresis of the denatured products. The collagenase hydrolysed insoluble collagen, reconstituted collagen fibrils and gelatin, but had no effect on haemoglobin or Pz-Pro-Leu-Gly-Pro-d-Arg (where Pz=4-phenylazobenzyloxycarbonyl). 3. The fibroblast collagenase was partially purified by gel filtration and the molecular weight was estimated as 38000. The activity of the partially purified enzyme was stimulated by 4-chloromercuribenzoate, inhibited by EDTA, cysteine, 1,10-phenanthroline and serum, but was unaffected by di-isopropyl phosphorofluoridate, Tos-LysCH(2)Cl and pepstatin. 4. Long-term cell cultures originating from rabbit skin or synovium from rabbits with experimentally induced arthritis also secreted specific collagenase. Human fibroblasts released only very small amounts of collagenase.