Research article

Microenvironmental changes during differentiation of mesenchymal stem cells towards chondrocytes

Farida Djouad^1,2 , Bruno Delorme³ , Marielle Maurice⁴ , Claire Bony^1,2 , Florence Apparailly^1,2 , Pascale Louis-Plence^1,2 , François Canovas⁵ , Pierre Charbord³ , Danièle Noël^{* 1,2} and Christian Jorgensen^{* 1,2,5}

¹Inserm, U 844, 80 avenue Augustin Fliche, Montpellier, F-34091 France

²Université Montpellier 1, 2 rue Ecole de Médecine, Montpellier, F-34000 France

³Inserm, ESPRI EA3855, 10 bld Tonnellé, Tours, F-37032 France

⁴Genopoietic, 1390 rue Centrale, Beynost-Miribel, F-01708 France

⁵CHU Montpellier, Hôpital Lapeyronie, avenue du Doyen Gaston Giraud, Montpellier, F-34295 France

author email corresponding author email* Contributed equally

Arthritis Research & Therapy 2007, 9:R33doi:10.1186/ar2153

Published:	29 March 2007

Abstract

Chondrogenesis is a process involving stem-cell differentiation through the coordinated effects of growth/differentiation factors and extracellular matrix (ECM) components. Recently, mesenchymal stem cells (MSCs) were found within the cartilage, which constitutes a specific niche composed of ECM proteins with unique features. Therefore, we hypothesized that the induction of MSC differentiation towards chondrocytes might be induced and/or influenced by molecules from the microenvironment. Using microarray analysis, we previously identified genes that are regulated during MSC differentiation towards chondrocytes. In this study, we wanted to precisely assess the differential expression of genes associated with the microenvironment using a large-scale real-time PCR assay, according to the simultaneous detection of up to 384 mRNAs in one sample. Chondrogenesis of bone-marrow-derived human MSCs was induced by culture in micropellet for various periods of time. Total RNA was extracted and submitted to quantitative RT-PCR. We identified molecules already known to be involved in attachment and cell migration, including syndecans, glypicans, gelsolin, decorin, fibronectin, and type II, IX and XI collagens. Importantly, we detected the expression of molecules that were not previously associated with MSCs or chondrocytes, namely metalloproteases (MMP-7 and MMP-28), molecules of the connective tissue growth factor (CTGF); cef10/cyr61 and nov (CCN) family (CCN3 and CCN4), chemokines and their receptors chemokine CXC motif ligand (CXCL1), Fms-related tyrosine kinase 3 ligand (FlT3L), chemokine CC motif receptor (CCR3 and CCR4), molecules with A Disintegrin And Metalloproteinase domain (ADAM8, ADAM9, ADAM19, ADAM23, A Disintegrin And Metalloproteinase with thrombospondin type 1 motif ADAMTS-4 and ADAMTS-5), cadherins (4 and 13) and integrins (α4, α7 and β5). Our data suggest that crosstalk between ECM components of the microenvironment and MSCs within the cartilage is responsible for the differentiation of MSCs into chondrocytes.