RANTES (CCL5) induces a CCR5-dependent accelerated shedding of syndecan-1 (CD138) and syndecan-4 from HeLa cells and forms complexes with the shed ectodomains of these proteoglycans as well as with those of CD44

Abstract

We recently demonstrated that RANTES forms complexes with CCR5, syndecan-1 (SD-1), SD-4, and CD44 expressed by human primary macrophages and that SD-1 and SD-4 but neither CD44 nor SD-2 coimmunoprecipitate with CCR5. Here we show that RANTES directly binds in a glycosaminoglycan-dependent manner to SD-1, SD-4, and CD44. Moreover, RANTES accelerates the shedding of SD-1 and SD-4 ectodomains from HeLa cells expressing CCR5 and, by contrast, has no effect on the constitutive shedding of CD44 from these cells. These accelerated sheddings are prevented by the MEK1/2 inhibitor, U0126, and by the protein kinase C inhibitor bisindolylmaleimide I. This indicates that both MAP kinase--and protein kinase C-dependent signaling pathways are involved in these RANTES-induced accelerated sheddings. RANTES also induces a decreased expression of SD-1 and SD-4 by HeLa cells expressing CCR5 and on the contrary an increased expression of CD44 by these cells. By contrast, RANTES neither accelerates the shedding of SD-1 and SD-4 ectodomains from HeLa cells lacking CCR5, nor changes the SD-1-, SD-4-, and CD44-plasma membrane expressions of these cells. CCR5 is therefore involved in the RANTES-induced accelerated shedding of SD-1 and SD-4 ectodomains. Nevertheless, the fact that RANTES stimulates in Hela cells (expressing or lacking CCR5) the mRNA synthesis of SD-1 and SD-4 indicates that the molecular events that follow the synthesis of these proteoglycans differ, according to the presence or not of CCR5. Finally, RANTES forms GAG-dependent complexes with the shed ectodomains of SD-1 and SD-4 as well as with those of CD44. The role of these events in the pathophysiology of RANTES deserves further study.

Technical Advance: Surface plasmon resonance-based analysis of CXCL12 binding using immobilized lentiviral particles

“…The N-terminal domain is unaffected at low GAG concentrations, allowing CXCL12:receptor binding. Our results are also consistent with results using 125 I-CXCL8 and 125 I-CCL3 with CXCR1-, CXCR2-, or CCR1-transfected CHO cell membranes [36], as well as with data from various laboratories showing that soluble heparin and heparan sulfate inhibit leukocyte responses [40,42]. Unfractionated heparin and the low MW heparin Tinzaparin inhibit CXCL12 binding to CXCR4-expressing CHO cells and human breast cancer cell lines, thus blocking signaling; these compounds might be useful in preventing chemokinedriven breast cancer metastasis [43].…”

Role of the Heparan Sulfate Proteoglycan Syndecan-1 (CD138) in Delayed-Type Hypersensitivity

“…Although this increase will at least be in part due to the higher quantity of chemokine-producing leukocytes in Sdc-1 KO tissues, it is also known that Sdc-1 is directly involved in modulating cytokine and chemokine function by promoting chemokine dimerization and via facilitation of receptor interactions (7,9,35,42). To date, interactions of Sdc-1 with the chemokines RANTES/CCL5 (19,34), eotaxin/CCL11, TARC/CCL17, MARC/ CCL7 (24), IL-8/CXCL8 (43), and KC/CXCL1 (23) have been demonstrated. In the DTH model, loss of Sdc-1 leads to a dysregulation of proinflammatory cytokine and chemokine expression, including several key players in the DTH reaction.…”

“…Elicitation of a DTH response led to a 67% increased induction of the Sdc-1-binding chemokine RANTES (34), in Sdc-1 KO mice over WT after 48 h, as determined by ELISA (Fig. 5A).…”

Mechanical strain regulates syndecan-4 expression and shedding in smooth muscle cells through differential activation of MAP kinase signaling pathways

“…However, only a select subset of these stimuli have been shown to act via MAP kinase signaling. In particular, ERK1/2 and PKC signaling have been shown to be required for RANTES-induced shedding of syndecan-1 and syndecan-4 in HeLa cells (5) and for EGF-and thrombin receptor-induced shedding in mouse epithelial cells (8). Most other reports on the mechanism of syndecan shedding have focused on the involvement of intracellular protein tyrosine kinase (29) and matrix metalloproteinase (MMP) (1,11,21) activity in this process.…”