Premium
Ultrastructural immunolocalization of type‐VI collagen and chondroitin sulphate in ligament
Author(s) -
Bray D. F.,
Bray R. C.,
Frank C. B.
Publication year - 1993
Publication title -
journal of orthopaedic research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.041
H-Index - 155
eISSN - 1554-527X
pISSN - 0736-0266
DOI - 10.1002/jor.1100110510
Subject(s) - microfilament , chemistry , extracellular matrix , matrix (chemical analysis) , ultrastructure , immunogold labelling , anatomy , type i collagen , microbiology and biotechnology , biophysics , biochemistry , biology , cytoskeleton , cell , chromatography , endocrinology
Immunological methods were used to determine the identity of the major components comprising a network of electron‐dense seams (described by the authors in a previous work) within the extracellular matrix of medial collateral ligament (MCL) from humans and rabbits. Tissue obtained from MCL midsubstance was subjected to pre‐embedding labelling with colloidal gold at the electron microscopic level with monoclonal antibodies (MAbs) against type‐VI collagen and chondroitin sulphate (CS), before and after digestion with chondroitinase ABC and testicular hyaluronidase. Tissue labelled with anti‐type‐VI MAbs showed gold conjugates attached to the microfilamentous component of the seams both before and after enzyme digestion, which confirmed the identity of the beaded microfilaments as type‐VI collagen. Treatment of the tissue with anti‐CS MAbs resulted in labelling of undigested tissue only. In these treatments, gold particles were found attached to granules that were interspersed throughout the network of type‐VI microfilaments. Both the granules and gold labels were absent from the network following enzyme digestion. Thin nonbeaded microfilaments that did not label with anti‐type‐VI MAbs also were present within the seams. The loss of these nonbeaded microfilaments following enzyme digestion suggested that they might represent strands of hyaluronan. The codistribution and seqestering of type‐VI collagen and CS within discrete seams or channels suggests that these regions of the MCL midsubstance may contain higher concentrations of water than the surrounding dense fibrillar matrix.