Biomedical subjects

Doriane Richard

Publications and source records attributed to Doriane Richard.

4 recordsLinked to original sources

PubMed2006

Involvement of toll-like receptor 4 in the inflammatory reaction induced by hydroxyapatite particles.

Hydroxyapatite (HA) is widely used to coat metal parts in order to improve their biocompatibility. Analysis of retrieved tissues associated with failed implants, suggest that phagocytosis of HA wear debris by monocytes/macrophages might provide a potent stimulus for the release of a variety of cytokines. Phagocytosis involved a large variety of cellular receptors like toll-like receptors that results in activation of the transcriptional nuclear factor-kappaB (NF-kappaB) via a cell-signalling pathway. In the present paper, we aimed to evaluate the role of the toll-like receptor 4 (TLR4) in the production of inflammatory cytokines induced by HA particles using TLR4(+) and TLR4(-) peritoneal macrophages. We investigated the production of TNF-alpha and the activation of the nuclear transcription factor NF-kappaB. Our data clearly show for the first time that the production of TNF-alpha by macrophages exposed to HA particles was TLR4 dependent but not the activation of NF-kappaB. All these results open future therapies to reduce the inflammatory response induced by HA biomaterials.

Animals↗

PubMed2002

Butyric acid increases invasiveness of HL-60 leukemia cells: role of reactive oxygen species.

Butyric acid (BA) induces differentiation of human leukemia, including HL-60 cells. By using a fluorescent probe, we showed that reactive oxygen species (ROS) were generated in BA-treated cells. BA-induced differentiation was accompanied with an increased secretion of pro-matrix metalloproteinase (MMP)-9. Both phenomena were inhibited by antioxidants. Tissue inhibitors of MMP (TIMP)-1 and -2 secretion were increased by BA, but differently affected by antioxidants. By contrast, BA did not affect MMP-9 mRNA, and decreased TIMP-1 and TIMP-2 mRNA levels. In addition, migratory and invasive properties of HL-60 cells were enhanced by BA, but differently affected by antioxidants. Altogether, these results indicate that ROS are messengers of BA-induced differentiation and increased invasiveness.

Antioxidants↗

PubMed2002

Free radical production and labile iron pool decrease triggered by subtoxic concentration of aclarubicin in human leukemia cell lines.

Aclarubicin (ACLA), which belongs to the antracycline class of antineoplasic agents, has been demonstrated as a differentiating agent for a broad range of human solid tumors and leukemia. By using dihydroethidium as a fluorescent probe, we show the ability of subtoxic (i.e. differentiating) concentration of ACLA to generate reactive oxygen species in both K562 and HL-60 leukemia cell lines. Besides, we have used a calcein-based spectrofluorimetric assay to determine the influence of ACLA treatment on the cellular labile iron pool (LIP). In both cell lines, the LIP level was markedly decreased in the presence of ACLA. Nevertheless, whereas ACLA-induced differentiation was obviously ROS-dependent, the LIP decrease was rather ROS-independent.

Aclarubicin↗

PubMed2002

Involvement of reactive oxygen species in aclarubicin-induced differentiation and invasiveness of HL-60 leukemia cells.

Aclarubicin (ACLA), which belongs to the anthracycline class of antineoplastic agents, has been demonstrated as a differentiating agent of human leukemia, including HL-60 cells. We report here on the incidence of ACLA-induced differentiation on matrix metalloproteinase (MMP) expression and cell invasiveness. The aim of this study was to investigate the involvement of reactive oxygen species (ROS) as mediators of ACLA-induced effects. By using a fluorescent probe, we showed that subtoxic (i.e. differentiating) concentration of ACLA generate reactive oxygen species in HL-60 cells. ACLA-differentiated cells exhibited an increased proMMP-9 secretion which has been observed by gelatin zymography and immunoassay. Antioxidants were able to inhibit ACLA-induced differentiation and proMMP-9 secretion. Furthermore, RT-PCR showed that ACLA increased MMP-9 and tissue inhibitor of MMP (TIMP-1) expression in a ROS-dependent manner. In addition, the migration and invasion capacities of HL-60 cells were enhanced by ACLA treatment, but only partially reversed by antioxidants. Altogether, these results evidenced ROS as messengers of ACLA-induced differentiation and MMP-9 expression.

Aclarubicin↗