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F Rougier

Publications and source records attributed to F Rougier.

13 recordsLinked to original sources
PubMed1997

Production and metabolism of platelet-activating factor by human bone marrow cells.

Platelet-activating factor (PAF) is a phospholipid mediator of inflammation present in the human bone marrow. Freshly isolated human mononuclear bone marrow cells and marrow stromal cell cultures produced PAF under calcium ionophore (2 microM) and LPS (10 micrograms/ml) stimulation. By contrast, M-CSF (1000 U/ml), GM-CSF (100 ng/ml), IL1, IL3, IL6 and stem cell factor (10 ng/ml) did not stimulate PAF production. Marrow stromal cells produced 50-fold more PAF than freshly isolated mononuclear marrow cells, suggesting that stromal cells might be the major source of the human marrow-derived PAF. Mononuclear marrow cells and stromal cell cultures metabolized PAF with 1-alkyl-2-acyl-glycerophosphocholine as the major metabolic product. PMSF and p-BPB decreased the catabolism of PAF by freshly isolated marrow cells, but not by stromal cell cultures. While stromal cells rather than haematopoietic progenitors might be a major source of the human bone-marrow-derived PAF, both cell types metabolize it, suggesting their putative role in the regulation of PAF concentration in the human bone marrow.

Bone Marrow↗
PubMed1997

Presence and metabolism of lyso platelet-activating factor in human bone marrow.

Lyso platelet-activating factor (PAF) is the precursor of PAF, an inflammatory phospholipid molecule present in human bone marrow. The present study shows that in healthy volunteers lyso PAF concentrations are significantly lower (P = 0.0001, Mann-Whitney U-test) in bone marrow plasma (594 +/- 67 ng/ml, n = 47) than in blood plasma (1448 +/- 99 ng/ml, n = 31). Marrow plasma lyso PAF concentrations are similar in patients with lymphoid and nonlymphoid malignancies as compared with controls. Freshly isolated mononuclear marrow cells and cultures of marrow stromal cells contain lyso PAF. Experiments with [3H]lyso PAF indicate that human mononuclear bone marrow cells and marrow stromal cells actively acylate lyso PAF into a 1-alkyl analogue of phosphatidylcholine. Results of this investigation indicate: (1) that lyso PAF is present in human marrow cells and plasma; and (2) that marrow cells and stromal cells metabolize it, thus suggesting their role in the regulation of lyso PAF amounts in human bone marrow.

Aged↗
PubMed1997

Platelet-activating factor and antagonists modulate DNA synthesis in human bone marrow stromal cell cultures.

Platelet-activating factor (PAF) is present in the human bone marrow. We have investigated the effect of PAF and antagonists (BN 52,021 and CV 3988) on the growth of human marrow stromal cells. PAF (1 microM) stimulates and PAF antagonists (0.1-1 microM) inhibit [3H]thymidine incorporation in cells grown in 5% serum. The catabolism of PAF by stromal cells was inhibited by CV 3988 suggesting the presence of specific PAF receptor on cells. PAF and antagonists (0.1 nM-10 microM) had no effect on cells cultured in high serum concentration (20%) or in low serum concentration (1%) with 0.5 ng/ml of basic fibroblast growth factor (bFGF). This study indicates for the first time that PAF modulates the serum-induced but not the bFGF-induced growth of marrow stromal cells. The interactions between PAF and stromal cells during inflammatory marrow events such as myelofibrosis deserve to be assessed.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1997

Spontaneous and inducible production of macrophage colony-stimulating factor by human bone marrow stromal cells.

Macrophage Colony-Stimulating Factor (M-CSF), which is permanently present in blood and human bone marrow, regulates the proliferation, differentiation and functions of cells of the mononuclear-phagocytic lineage. By using Reverse-Transcriptase Polymerase Chain Reaction (RT-PCR) we demonstrate that human marrow stromal cells express two types of M-CSF transcripts that are translated into the secreted form and the membrane anchored form. By using a specific and sensitive ELISA, we found that the spontaneous production of M-CSF by human marrow stromal cells is enhanced after stimulation with lipopolysaccharide (LPS), phorbol myristic acetate (PMA) and most interestingly by the lipidic mediator of inflammation platelet-activating factor (PAF). Thus, marrow stromal cells might represent a regulated cell source of bone marrow-derived M-CSF. These results not only emphasize the importance of the bone marrow environment in the control of human hematopoiesis but also evidence, for the first time, the potential role of PAF in the marrow cytokine network during inflammatory processes.

Bone Marrow↗
PubMed1996

Copper and zinc exposure of zebrafish, Brachydanio rerio (Hamilton-Buchaman): effects in experimental Listeria infection.

To investigate the effects of heavy metals on susceptibility of fish to Listeriosis, normal zebrafish, Brachydanio rerio (Hamilton-Buchanan), were exposed to varying concentrations of zinc (0.05, 0.15, and 0.25 mg/liter) and copper (0.05, 0.10, and 0.15 mg/liter). During copper exposure, this heavy metal did not accumulate in zebrafish kidney. Unlike copper, a small amount of zinc accumulated in kidneys of fish exposed at 0.25 mg/liter. To estimate the effects of this heavy metal on listerial infection, the mortality of fish and the number of viable bacteria in fish kidney were determined at various times (1, 4, 7, and 10 days) after ip challenge with Listeria monocytogenes (strain 31386, serotype 4b). The results indicate that the number of colony-forming units in zinc-exposed fish decreased at 4, 7, and 10 days after challenge with 0.2 x LD50 of viable bacteria. In contrast, copper-exposed fish indicated both decreases and increases in the number of colony-forming units depending on the concentration of L. monocytogenes used.

Adjuvants, Immunologic↗
PubMed1996

Human bone marrow fibroblasts--an overview of their characterization, proliferation and inflammatory mediator production.

Bone marrow fibroblasts regulate hematopoiesis by interacting directly (cell-to-cell contact) with hematopoietic cells and by secreting regulatory molecules (such as GM-CSF, M-CSF, IL6 and LIF) that modulate hematopoiesis either in a positive or a negative manner. Several cytokines (such as bFGF, EGF, PDGF and TGF-beta) affect the growth of human marrow fibroblasts in vitro. Further in vivo studies are still required to clarify the role of marrow fibroblasts and their interactions with hematopoietic progenitors during myelofibrosis and leukemic diseases.

Bone Marrow↗
PubMed1996

PAF and hematopoiesis. VIII. Biosynthesis and metabolism of PAF by human bone marrow stromal cells.

Human bone marrow stromal cells were studied for their ability to synthesize and to metabolize platelet-activating factor (PAF), a lipidic compound with potent immunoregulatory properties. When stimulated with 2 microM calcium ionophore for 60 minutes, cultures of stromal cells increased their PAF production (3.52 +/- 0.91 ng/1 x 10(6) cells) compared with controls (0.82 +/- 0.13 ng/1 x 10(6) cells). Addition of exogenous lyso PAF (100 nM) and acetyl-CoA (100 microM) during calcium ionophore stimulation did not change the PAF production. The synthesis of PAF was not influenced by the concentration of albumin in the incubation buffer. The PAF from stromal cells exhibited a hexadecyl chain at the sn-1 position of the molecule, as determined by reverse-phase HPLC. While stromal cells contained low amounts of PAF acetylhydrolase activity and did not secrete it in the culture medium, they metabolized exogenous PAF with 1-alkyl-2-acyl-glycero-phosphocholine and neutral lipids as the major metabolic products. The present results are the first to demonstrate the synthesis and metabolism of PAF by human bone marrow stromal cells. These data suggest that they might be a source of the PAF found in the human bone marrow and/or might be important in the regulation of its levels. The role of PAF on the proliferation and functions of human hematopoietic cells deserves investigation.

Bone Marrow↗
PubMed1992

In vitro effects of substance P and somatostatin on lymphoproliferation in rainbow trout (Salmo gairdneri).

Lymphocytes from peripheral blood of rainbow trout are put in the presence of increasing concentrations of substance P (SP) and somatostatin (SOM). We have shown that SP stimulates and SOM inhibits lymphoproliferation and that the effects are dose dependent. These results suggest that SP and SOM receptors may exist on fish peripheral blood lymphocytes. When cells are stimulated by PHA or LPS, the presence of SP enhances the response to PHA whereas it only modifies the response to LPS to a slight extent. The presence of SOM inhibits PHA- or LPS-induced stimulation. The inhibition of the proliferation is higher in the case of LPS-stimulated cells. These results suggest that there is an unequal distribution of neuropeptide receptors among the various lymphocyte subpopulations.

Animals↗
PubMed1984

[Prevention].

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Attitude to Health↗
PubMedDate not supplied

Platelet-activating factor and haematopoiesis. XI. Platelet-activating factor has no effect on the production of interleukin-6 and tumor necrosis factor-alpha by human bone marrow stromal cells.

PAF is a phospholipid mediator of inflammation with stimulates IL-6 production by murine skin fibroblasts. Although PAF is present in human bone marrow, its role in haematopoiesis is unknown. We have assessed whether PAF stimulates IL-6 and TNF-alpha production by human bone marrow stromal cells (mostly fibroblast-like cells). We report that PAF (1 nM to 10 microM) has no effect on the synthesis of IL-6 and TNF-alpha by human bone marrow stromal cells. This difference may be due to the widely accepted concept "tissue-specific fibroblasts". The role of PAF in the regulation of human haematopoiesis remains to be elucidated.

Bone Marrow↗