Human cartilage lysozyme

Abstract

A B S T R A C T The lysozyme content of human cartilage was measured by incubation of lyophilized, powdered cartilage in a variety of buffers and salt solutions, and the factors controlling the binding of lysozyme within cartilage were studied. Lysozyme was extracted from hyaline cartilage by buffers of pH greater than 9.0, by solutions 1 M in monovalent cations, and by solutions 0.12-0.40 M in divalent cations. The ability of cations to extract lysozyme from cartilage agreed with their known affinities for binding to chondroitin sulfate. The total extractable lysozyme content of five samples of human costal cartilage ranged from 1.45 to 3.36 Ag lysozyme per mg of cartilage; for five samples of hyaline cartilage from peripheral joints the range was 0.80-3.03 Ag lysozyme per mg of cartilage. Cartilage incubated in excess exogenous lysozyme could bind 0.053 equivalents of lysozyme per equivalent of chondroitin sulfate. Fibrocartilage and synovium from knee joints yielded no detectable lysozyme, despite the fact that synovium, a tissue rich in lysosomes, contained measurable quantities of P-glucuronidase. Lysozyme extraction from cartilage was not augmented by incubation with streptolysin S. When incubation was carried out with mild extraction techniques, lysozyme extraction from cartilage tended to parallel uronic acid release, both as a function of time and from one specimen to another. The active material as lysozyme. Lysozyme occurs in human hyaline cartilage as a counterion to polyanionic glycosaminoglycans. Carextracted from cartilage met five criteria for identification tilage lysozyme appears to be extracellular and nonlysosomal. Degradation of cartilage may contribute to the increased serum and synovial fluid lysozyme levels often present in patients with rheumatoid arthritis.

Natural origin scaffolds with in situ pore forming capability for bone tissue engineering applications

“…The main advantage of biodegradable over non-biodegradable materials is the disappearance of implanted foreign material, which could elicit foreign body reactions from the host's defence system during their long-term contact with a living structure. Since lysozyme is present in cellular lysosomes and lysosomal rupture is associated with inflammation, it has been assumed that the source of the increased lysozyme activity is the release of enzyme from the lysosomes of phagocytic cells [28]. When any material is implanted, an acute inflammatory response will occur, with the consequent pH decrease and secretion of increased levels of lysozyme.…”

Lactoferrin and lysozyme levels in synovial fluid

“…In addition, lysozyme is found in monocytes and macrophages (16) and is also a nonlysosomal component of the extracellular matrix of cartilage (17)(18)(19) …”

Lysozyme Concentrations in Synovial Fluid, Pleural Fluid and Thoracic Duct Lymph in Rheumatoid Arthritis

“…trauma (9 patients), osteoarthritis (7 patients), a Yersinia enterocolitica infection (4 patients) and Reiter's syndrome (3 70 M . Klockars ( 7 ) serum and for antibodies to Yersinia enterocolitica (type 3 or 9) micro-organism as well as on synovial fluid analysis; and (c) roentgenological findings. In most patients, knee joint exudate was obtained by routine diagnostic arthrocentesis and the synovial fluid analysed for white cell and differential cell counts and after centrifugation for total protein, glucose concentration, and rheumatoid factor (Waaler-Rose and latex fixation tests).…”