The concentration, gene expression, and spatial distribution of aggrecan in canine articular cartilage, meniscus, and anterior and posterior cruciate ligaments: a new molecular distinction between hyaline cartilage and fibrocartilage in the knee joint.
The concentration, spatial distribution, and gene expression of aggrecan in meniscus, articular cartilage, and the anterior and posterior cruciate ligaments (ACL and PCL) was determined in the knee joints of five mature dogs. An anti-serum against peptide sequences specific to the G1 domain of aggrecan was employed in competitive-inhibition ELISA of guanidine HCl extracts and immunofluorescence microscopy. Gene expression was determined by Taqman real-time PCR. The concentration of aggrecan in articular cartilage (240.1 +/- 32 nMol/g dry weight) was higher than that in meniscus (medial meniscus: 33.4 +/- 4.3 nMol/g) and ligaments (ACL: 6.8 +/- 0.9 nMol/g). Aggrecan was more concentrated in the inner than the outer zone of the meniscus. Aggrecan in meniscus showed an organized, spatial network, in contrast to its diffuse distribution in articular cartilage. Thus, differences in the concentration, gene expression, and spatial distribution of aggrecan constitute another molecular distinction between hyaline cartilage and fibrocartilage of the knee.
Valiyaveettil
Manojkumar
M
Department of Biomedical Engineering, Lerner Research Institute and Orthopaedic Research Center, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
Mort
John S
JS
McDevitt
Cahir A
CA
D053674:Aggrecans; D000818:Animals; D016118:Anterior Cruciate Ligament / Q000502:physiology; D002356:Cartilage / Q000502:physiology; D002358:Cartilage, Articular / Q000502:physiology* / Q000648:ultrastructure; D002417:Cattle; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis*; D015870:Gene Expression / Q000502:physiology; D006818:Hyalin; D018960:Hyaluronan Receptors / Q000302:isolation & purification; D007719:Knee Joint / Q000166:cytology*; D037181:Lectins, C-Type; D008592:Menisci, Tibial / Q000502:physiology / Q000648:ultrastructure; D008856:Microscopy, Fluorescence; D016119:Posterior Cruciate Ligament / Q000502:physiology; D017434:Protein Structure, Tertiary; D011509:Proteoglycans / Q000096:biosynthesis*
D053674:Aggrecans; D016326:Extracellular Matrix Proteins; D018960:Hyaluronan Receptors; D037181:Lectins, C-Type; D011509:Proteoglycans