Prostaglandin E2 and prostaglandin F2α differentially modulate matrix metabolism of human nucleus pulposus cells

Abstract

Prostaglandin (PG) actions on disc metabolism are unclear even though certain PGs are highly expressed by disc cells under inflammatory conditions and nonsteroidal anti-inflammatory drugs (NSAIDs) are frequently used to block PG production to treat back pain. Hence this study aimed to (1) quantify gene expression of arachidonic acid cascade components responsible for PG synthesis and (2) examine the effects of key PGs on disc matrix homeostasis. Microarray analysis revealed that inflammatory stress increases expression of synthases and receptors for prostaglandin E2 (PGE2) and prostaglandin F2α (PGF2α), resulting in elevated PGE2 and PGF 2α production in conditioned media of disc cells. PGE 2 diminished disc cell proteoglycan synthesis, in a dose-dependent manner. Semiquantitative RT-PCR revealed differential effects of PGE2 and PGF2α on disc cell expression of key matrix structural genes, aggrecan, versican, collagens type I and II. PGE2 and PGF 2α also decreased message for the anabolic factor, IGF-1. PGE2 decreased mRNA expression for the anti-catabolic factor TIMP-1 while PGF2α increased mRNAs for catabolic factors MMP-1 and MMP-3. Thus, PGE2 and PGF2α may have an overall negative impact on disc matrix homeostasis, and the use of NSAIDs may impact disc metabolism as well as treat back pain. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.