Induction of CD44 and MMP Expression by Hyaluronidase Treatment of Articular Chondrocytes

Abstract

In this study, the effects of fragmentation of the glycosoaminoglycans of the cell-associated matrix by hyaluronidase (HAase) on the expression of CD44 receptor and matrix metalloproteinase (MMP) mRNAs in cultured articular chondrocytes were examined. Chondrocytes, isolated from rabbit and bovine articular cartilage, were treated with bovine testicular HAase (0-200 units/ml) in the presence or absence of an antibody for CD44. The mRNA levels of CD44, CD44 variant (CD44v), MMPs (MMP-1, -3 and -9), and tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) were determined by RT-PCR. The treatment of cultured chondrocytes with HAase resulted in the production of low molecular weight fragments of hyaluronan (HA). The expression of CD44, CD44v and MMP (MMP-1, -3 and -9) mRNAs, but not TIMP-1 or TIMP-2 mRNA, was up-regulated in the cultures treated with HAase, whereas this expression was not affected by treatment with purified HA of 1.0 x 10(5) Da. Furthermore, the induction of CD44 and MMPs on treatment with HAase was suppressed by an anti-CD44 antibody. The results suggest that the fragmentation of HA may lead to cartilage destruction in terms of the enhanced expression of MMPs as well as the upregulation of CD44.

γ-Secretase-Dependent Proteolysis of CD44 Promotes Neoplastic Transformation of Rat Fibroblastic Cells

“…Next, we treated WT 44 cells with hyaluronidase. Hyaluronidase is known to generate hyaluronan oligosaccharides (17), which, in turn, can promote CD44 cleavage (20). Hyaluronidase treatment resulted in an increased expression of both CD44-CTF and the 38 kDa band (Fig.…”

“…Our initial hypothesis was that hyaluronan binding to CD44 might promote Ret-induced transformation of Rat-1 cells. We tested this by treating MEN2A-transformed cells with bovine testis hyaluronidase, which disrupts extracellular hyaluronan-cell interactions (17). This treatment did not affect the anchorageindependent growth capability of the cells (data not shown).…”

4-Methylumbelliferone Diminishes Catabolically Activated Articular Chondrocytes and Cartilage Explants via a Mechanism Independent of Hyaluronan Inhibition

“…What is clear from all the studies is that HA is lost from the articular cartilage in a coordinate fashion with the loss of aggrecan (16,19,20). Experimentally, we have tried to mimic the loss of HA and proteoglycan via the use of HA oligosaccharides to displace the pericellular matrix (21)(22)(23)(24) or with hyaluronidases to remove the HA-rich pericellular matrix (21,22,25). With both approaches we observe the induction of pro-catabolic state by the chondrocytes, one that includes the up-regulation of MMP2, -3, -9, and -13 (24 -28) as well as ADAMTS4 and ADAMTS5 (28).…”

Role of sialidase in Mycoplasma alligatoris-induced pulmonary fibroblast apoptosis

“…Although there is no consensus on the molecular mechanisms by which CD44 is linked to apoptosis (Hauptschein et al, 2005), HA fragments generated from the ECM by hyaluronidases stimulate HER2 and c-Src tyrosine kinase phosphorylation of cytoskeletal proteins, and Rho GTPase signaling, through desialylated CD44 receptor-specific networks (Ponta et al, 2003;Turley et al, 2002). As we observed in the present study, expression of CD44 itself may not change following ligand binding, depending on the cell type or basal level of CD44 expression (Ohno-Nakahara et al, 2004), but the observed increase in CD95 expression is consistent with transcription factor upregulation following HA fragment binding by desialylated CD44 (Fieber et al, 2004;Ohno et al, 2005). CD44 genes are annotated in fish, amphibian, and avian genomes, but our data establish for the first time that reptile cells also express a CD44 homolog, and further suggest that CD44-specific tyrosine kinase signaling networks are also conserved across vertebrate species.…”