title: Expression of Notch family members in cultured murine articular chondrocytes.
abstract: The Notch family is involved in cell differentiation during embryogenesis. Osteoarthritic chondrocytes undergo morphological and biochemical changes leading to the de-differentiation process. In the study reported here, we were interested in the involvement of the Notch pathway in murine articular chondrocyte de-differentiation. Articular chondrocytes were subjected to several cell culture passages and treated with or without a Notch inhibitor, N-[N-(3, 5-difluorophenacetyl-L-alanyl)]-S-phenylglycine t-Butyl Ester (DAPT). Chondrocyte morphology was studied using optical microscopy. Immunocytochemistry and immunoblot were performed to study the expression of collagens and Notch family members. Without DAPT treatment, chondrocyte de-differentiation resulted in fibroblast-like morphology. This was confirmed by immunocytochemical staining and immunoblot analysis, which showed an increase in collagen type I (col I) and a decrease in collagen type II (col II) expression. With DAPT treatment, de-differentiation was delayed. Immunocytochemistry and immunoblot analysis showed during the first passages inhibition of col II expression, which then was re-instituted during the last passage, suggesting chondrocyte re-differentiation. In the study reported here, we showed that inhibition of the Notch receptor not only delayed the de-differentiation process, but also chondrocyte re-differentiation, which confirms the involvement of the Notch pathway in chondrocyte de-differentiation.
authors: Osteoarthritis-Osteoporosis Research Laboratory, Department of Rheumatology, LaRabta Hospital, Tunis, Tunisia. nadiasassitn@yahoo.com
authors: N
authors: N
authors: Sassi
authors: L
authors: L
authors: Laadhar
authors: M
authors: M
authors: Mahjoub
authors: M
authors: M
authors: Driss
authors: M
authors: M
authors: Zitouni
authors: K
authors: K
authors: Benromdhane
authors: S
authors: S
authors: Makni
authors: S
authors: S
authors: Sellami
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000235:genetics; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D003094:Collagen / Q000235:genetics / Q000378:metabolism; D024042:Collagen Type I / Q000235:genetics / Q000378:metabolism; D024043:Collagen Type II / Q000235:genetics / Q000378:metabolism; D005109:Extracellular Matrix / Q000235:genetics / Q000378:metabolism; D007596:Joints / Q000378:metabolism; D051379:Mice; D051880:Receptors, Notch / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D014280:Triglycerides / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D024042:Collagen Type I; D024043:Collagen Type II; D051880:Receptors, Notch; D014280:Triglycerides; D005680:gamma-Aminobutyric Acid; D003094:Collagen; C057077:1,2-dilinolenoyl-3-(4-aminobutyryl)propane-1,2,3-triol