Identification of phenotypic discriminating markers for intervertebral disc cells and articular chondrocytes.

Objective: The present study was conducted to improve our knowledge of intervertebral disc (IVD) cell biology by comparing the phenotype of nucleus pulposus (NP) and annulus fibrosus (AF) cells with that of articular chondrocytes (ACs).

Methods: Rabbit cells from NP and AF were isolated and their phenotype was compared with that of AC by real-time PCR analysis of type I (COL1A1), II (COL2A1) and V (COL5A1) collagens, aggrecan transcript (AGC1), matrix Gla protein (MGP) and Htra serine peptidase 1 (Htra1).

Results: Transcript analysis indicated that despite certain similarities, IVD cells exhibit distinct COL2A1/COL1A1 and COL2A1/AGC1 ratios as compared with AC.