The International Journal of Biochemistry & Cell Biology 41 (2009) 1102–1115 Contents lists available at ScienceDirect The International Journal of Biochemistry & Cell Biology journal homepage: www.elsevier.com/locate/biocel TIMP-1 binding to proMMP-9/CD44 complex localized at the cell surface promotes erythroid cell survival Elise Lambert ∗,1 , Lucie Bridoux 1 , Jérôme Devy, Emilie Dassé, Marie-Line Sowa, Laurent Duca, William Hornebeck, Laurent Martiny, Emmanuelle Petitfrère-Charpentier Université de Reims Champagne-Ardenne (URCA), CNRS UMR 6237 (MEDyC), Laboratoire Signalisation et Récepteurs Matriciels (SiRMa), IFR53 Interactions Cellules-Microenvironnement: Cancer, Inflammation, Infections, Vieillissement, UFR Sciences Exactes et Naturelles et UFR Médecine, BP 1039, 51687 Reims, France article info Article history: Received 27 May 2008 Received in revised form 7 October 2008 Accepted 10 October 2008 Available online 25 October 2008 Keywords: TIMP-1 proMMP-9 CD44 Receptor Erythroid cell survival abstract Besides its ability to inhibit MMP activity, TIMP-1 exhibits other biological functions. We earlier reported that TIMP-1 induced UT-7 erythroid cell survival through activation of the JAK2/PI 3-kinase/Akt pathway and we now aim to determine whether the TIMP-1 anti-apoptotic effect requires MMP involvement. We first show that proMMP-9 was expressed in UT-7 cells and associated with the cell plasma membrane. Such proMMP-9 localization was crucial for TIMP-1 intracellular signalling since (i) TIMP-1 specifically bound to proMMP-9 and (ii) proMMP-9 silencing abrogated the TIMP-1 effect. We also demonstrated that TIMP-1 anti-apoptotic effect was independent on MMP inhibition since MMP-9 function blocking anti- bodies as well as a synthetic MMP inhibitor were unable to reproduce TIMP-1 effect. Nevertheless, these compounds prevented TIMP-1 binding to proMMP-9 and subsequently abolished TIMP-1-induced cell survival. We finally demonstrated that CD44 anchored proMMP-9 to the plasma membrane and enabled TIMP-1-mediated signal transduction. Therefore, our results indicate that the anti-apoptotic signalling of TIMP-1 depends on the formation of a ternary complex between TIMP-1, proMMP-9 and CD44 at the UT-7 erythroid cell surface. © 2008 Elsevier Ltd. All rights reserved. 1. Introduction The extracellular matrix (ECM) not only constitutes the tissue framework but also plays a dynamic role by interacting with the surrounding cells. These cell–matrix interactions enable cell–cell communications, thus regulating cellular functions such as prolif- eration, differentiation and survival (for reviews Tsilibary, 2003; Arai et al., 2005). Both normal development and function of the organism require ECM turnover and remodeling which involve the activity of neutral proteases such as the matrix metalloproteinases (MMPs). The role of MMPs has been widely documented in many physiological and pathological processes including angiogenesis and tumor invasion (Massova et al., 1998). Most MMPs are secreted as latent precursor forms (proMMPs) making enzyme activation a critical step in the regulation of MMP proteolytic activity. One of the Abbreviations: TIMP-1, tissue inhibitor of metalloproteinases-1; MMP, matrix metalloproteinase. ∗ Corresponding author at: URCA, CNRS UMR 6237 (MEDyC), Laboratoire Signal- isation et Récepteurs Matriciels (SiRMa), Moulin de la Housse, 51687 Reims Cedex 2, France. Tel.: +33 3 26 91 32 69; fax: +33 3 26 91 83 66. E-mail address: elise.lambert@univ-reims.fr (E. Lambert). 1 These authors contributed equally to this study. critical determinant for optimal MMP function relies on its localiza- tion at the cell surface (Sternlicht and Werb, 2001). Indeed, MMPs can transiently localize at the cell periphery in association with adhesion receptors or proteoglycans before being activated. Such mechanism has been described for proMMP-9 and MMP-9 in nor- mal and malignant cells and their specific localization has notably been reported to involve CD44 glycoprotein (Yu and Stamenkovic, 1999, 2000, 2004; Toth et al., 1997; Fridman et al., 2003; Redondo- Munoz et al., 2008). CD44 is an adhesion molecule expressed at the cell surface of many cells including the hematopoietic cells. The common form of CD44 expressed by the majority of hematopoietic cells is 85–90 kDa glycoprotein. Nevertheless, various isoforms of CD44 might be expressed depending on the state of differentiation of normal hematopoietic cells and their expressions might be down- regulated or upregulated in their leukemic counterparts (Kansas et al., 1990; Ghaffari et al., 1995, 1999). Accumulating evidence has demonstrated that CD44 overexpression is associated with tumor progression and metastasis of multiple cancers through the activa- tion of survival signalling pathway (Bourguignon et al., 2003; Wang et al., 2007). MMP activity is also tightly controlled by several endogenous inhibitors, among them the most thoroughly studied, the Tissue 1357-2725/$ – see front matter © 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.biocel.2008.10.017