title: Expression patterns of Notch receptors and their ligands in human osteoarthritic and healthy articular cartilage.
abstract: Notch pathway plays a pivotal role in cell fate determination. There is much interest surrounding its therapeutic potential, in osteoarthritis, but the expression profile of Notch-related molecules, as well as their relation with cartilage pathological parameters, remains unclear. The purpose of our study is to analyze the expression pattern of Notch family members, type II and type I collagen, in normal (healthy) and osteoarthritic human knee cartilage. Osteoarthritic cartilages were obtained from 3 patients undergoing a total knee replacement. Macroscopically normal cartilage was dissected from 3 human knees at the time of autopsy or surgery. Immunohistochemical staining was performed using Notch1,2,3 and 4, Delta, Jagged, type II collagen and type I collagen antibodies. In healthy cartilage, type II collagen was abundantly expressed while type I was absent. This latter increased proportionally to the osteoarthritic grade. Type II collagen expression remained intense in osteoarthritic cartilage. In healthy cartilage as well as in cartilage with minor lesions, Notch family member's proteins were not or just weakly expressed at the surface and in the cells. However, Notch molecules were over-expressed in osteoarthritic cartilage compared to healthy one. This expression pattern was different according to the cartilage zone and the severity of OA. Our data suggest that Notch signaling is activated in osteoarthritic cartilage, compared to healthy cartilage, with a much more abundant expression in the most damaged areas.
authors.affiliation: Immuno-Rheumatology Research Laboratory, Rheumatology Department, La Rabta Hospital, University of Tunis-El Manar, 1007 Tunis, Tunisia.
authors.forename: M
authors.initials: M
authors.lastname: Mahjoub
authors.forename: N
authors.initials: N
authors.lastname: Sassi
authors.forename: M
authors.initials: M
authors.lastname: Driss
authors.forename: L
authors.initials: L
authors.lastname: Laadhar
authors.forename: M
authors.initials: M
authors.lastname: Allouche
authors.forename: M
authors.initials: M
authors.lastname: Hamdoun
authors.forename: K Ben
authors.initials: KB
authors.lastname: Romdhane
authors.forename: S
authors.initials: S
authors.lastname: Sellami
authors.forename: S
authors.initials: S
authors.lastname: Makni
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D001344:Autopsy; D002358:Cartilage, Articular / Q000378:metabolism / Q000473:pathology*; D019902:Chondrocytes / Q000378:metabolism / Q000473:pathology; D024043:Collagen Type II / Q000378:metabolism*; D005109:Extracellular Matrix / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D008024:Ligands; D008565:Membrane Proteins / Q000378:metabolism; D008875:Middle Aged; D010003:Osteoarthritis / Q000378:metabolism / Q000473:pathology*; D051881:Receptor, Notch1 / Q000378:metabolism*; D051883:Receptor, Notch2 / Q000378:metabolism; D012720:Severity of Illness Index; D015398:Signal Transduction; D013194:Staining and Labeling
chemical_list: D024043:Collagen Type II; D047908:Intracellular Signaling Peptides and Proteins; D008024:Ligands; D008565:Membrane Proteins; C497761:NOTCH1 protein, human; C497764:NOTCH2 protein, human; D051881:Receptor, Notch1; D051883:Receptor, Notch2; C064045:delta protein