Pigment epithelium derived factor—the product of the EPC-1 gene—is expressed by articular chondrocytes and up regulated in osteoarthritis

• Published in: Annals of the rheumatic diseases 2006-07, Vol.65 (7), p.965-967
• Main Authors: Pfander, D, Grimmer, C, Aigner, T, Swoboda, B, Schmidt, R, Cramer, T
• Format: Article
• Language: English
• Subjects: Arthritis; Biological and medical sciences; cartilage; Cartilage, Articular - metabolism; Case-Control Studies; Chondrocytes - metabolism; Diseases of the osteoarticular system; Eye Proteins - metabolism; Gene expression; Humans; Letters; Medical sciences; Miscellaneous. Osteoarticular involvement in other diseases; Nerve Growth Factors - metabolism; Osteoarthritis; Osteoarthritis - metabolism; pigment epithelium derived factor; Polymerase chain reaction; Real time; Rodents; Serpins - metabolism; Up-Regulation
• ISSN: 0003-4967; 1468-2060
• DOI: 10.1136/ard.2005.047431

(A) Sections of normal and OA cartilage stained with safranin O and immunostained for PEDF are demonstrated. (a) Normal articular cartilage (Mankin-1) with a smooth surface and a high content of proteoglycans (safranin O staining); (b) immunostaining for PEDF displayed single weak stained chondrocytes (arrows) in the middle zone (same specimen as that shown in (a)). (c) no immunostaining for PEDF were seen in the deep zone of this cartilage specimen; (d) moderate OA lesion (Mankin-5) with a decreased proteoglycan staining of the upper cartilage (safranin O staining); (e) immunohistochemical analysis of PEDF in an adjacent section showing an increased number of PEDF positive chondrocytes in the upper areas and within the deep zone; (PEDF stained chondrocytes are indicated by arrows); (f) PEDF chondrocytes in the deep zone of OA cartilage; (g) severe OA lesion (Mankin-11) with deep clefts, chondrocyte clusters, and a strong reduction of proteoglycans (safranin O staining); (h) immunohistochemical analysis of PEDF in the same section as that shown in (g) (note the strong immunostaining of clustered chondrocytes as indicated by the arrows); (i) severe OA cartilage specimen immunostained with a monclonal antibody against PEDF, showing the same cellular and pericellular staining pattern (two negative chondrocytes are indicated by arrows).