The Experts below are selected from a list of 8346 Experts worldwide ranked by ideXlab platform
Olivier Theodoly - One of the best experts on this subject based on the ideXlab platform.
-
the leukocyte stiffening property of plasma in early acute respiratory distress syndrome ards revealed by a microfluidic single Cell study the role of cytokines and protection with antibodies
Critical Care, 2015Co-Authors: Pascal Preira, Jeanmarie Forel, Philippe Robert, Paulin Negre, Martine Biarnespelicot, Francois Xeridat, Pierre Bongrand, Laurent Papazian, Olivier TheodolyAbstract:AbstractBackgroundLeukocyte-mediated pulmonary inflammation is a key pathophysiological mechanism involved in acute respiratory distress syndrome (ARDS). Massive sequestration of leukocytes in the pulmonary microvasculature is a major triggering event of the syndrome. We therefore investigated the potential role of leukocyte stiffness and adhesiveness in the sequestration of leukocytes in microvessels. MethodsThis study was based on in vitro microfluidic assays using patient sera. Cell stiffness was assessed by measuring the entry time (ET) of a single Cell into a microchannel with a 6 × 9–μm cross-section under a constant pressure drop (ΔP = 160 Pa). Primary neutrophils and monocytes, as well as the monocytic THP-1 Cell Line, were used. Cellular adhesiveness to human umbilical vein endothelial Cells was examined using the laminar flow chamber method. We compared the properties of Cells incubated with the sera of healthy volunteers (n = 5), patients presenting with acute cardiogenic pulmonary edema (ACPE; n = 6), and patients with ARDS (n = 22), of whom 13 were classified as having moderate to severe disease and the remaining 9 as having mild disease. ResultsRapid and strong stiffening of primary neutrophils and monocytes was induced within 30 minutes (mean ET >50 seconds) by sera from the ARDS group compared with both the healthy subjects and the ACPE groups (mean ET <1 second) (p < 0.05). Systematic measurements with the THP-1 Cell Line allowed for the establishment of a strong correlation between stiffening and the severity of respiratory status (mean ET 0.82 ± 0.08 seconds for healthy subjects, 1.6 ± 1.0 seconds for ACPE groups, 10.5 ± 6.1 seconds for mild ARDS, and 20.0 ± 8.1 seconds for moderate to severe ARDS; p < 0.05). Stiffening correlated with the cytokines interleukin IL-1β, IL-8, tumor necrosis factor TNF-α, and IL-10 but not with interferon-γ, transforming growth factor-β, IL-6, or IL-17. Strong stiffening was induced by IL-1β, IL-8, and TNF-α but not by IL-10, and incubations with sera and blocking antibodies against IL-1β, IL-8, or TNF-α significantly diminished the stiffening effect of serum. In contrast, the measurements of integrin expression (CD11b, CD11a, CD18, CD49d) and leukocyte–endothelium adhesion showed a weak and slow response after incubation with the sera of patients with ARDS (several hours), suggesting a lesser role of leukocyte adhesiveness compared with leukocyte stiffness in early ARDS. ConclusionsThe leukocyte stiffening induced by cytokines in the sera of patients might play a role in the sequestration of leukocytes in the lung capillary beds during early ARDS. The inhibition of leukocyte stiffening with blocking antibodies might inspire future therapeutic strategies.
-
The leukocyte-stiffening property of plasma in early acute respiratory distress syndrome (ARDS) revealed by a microfluidic single-Cell study: the role of cytokines and protection with antibodies
Critical Care, 2015Co-Authors: Pascal Preira, Jeanmarie Forel, Philippe Robert, Paulin Negre, Francois Xeridat, Pierre Bongrand, Laurent Papazian, Martine Biarnes-pelicot, Olivier TheodolyAbstract:AbstractBackgroundLeukocyte-mediated pulmonary inflammation is a key pathophysiological mechanism involved in acute respiratory distress syndrome (ARDS). Massive sequestration of leukocytes in the pulmonary microvasculature is a major triggering event of the syndrome. We therefore investigated the potential role of leukocyte stiffness and adhesiveness in the sequestration of leukocytes in microvessels. MethodsThis study was based on in vitro microfluidic assays using patient sera. Cell stiffness was assessed by measuring the entry time (ET) of a single Cell into a microchannel with a 6 × 9–μm cross-section under a constant pressure drop (ΔP = 160 Pa). Primary neutrophils and monocytes, as well as the monocytic THP-1 Cell Line, were used. Cellular adhesiveness to human umbilical vein endothelial Cells was examined using the laminar flow chamber method. We compared the properties of Cells incubated with the sera of healthy volunteers (n = 5), patients presenting with acute cardiogenic pulmonary edema (ACPE; n = 6), and patients with ARDS (n = 22), of whom 13 were classified as having moderate to severe disease and the remaining 9 as having mild disease. ResultsRapid and strong stiffening of primary neutrophils and monocytes was induced within 30 minutes (mean ET >50 seconds) by sera from the ARDS group compared with both the healthy subjects and the ACPE groups (mean ET
Paolo Bellavite - One of the best experts on this subject based on the ideXlab platform.
-
Fibronectin Gene Up-regulation by Arnica montana in Human Macrophages: Validation by Real-Time Polymerase Chain Reaction Assay.
Homeopathy : the journal of the Faculty of Homeopathy, 2020Co-Authors: Marta Marzotto, Fabio Arruda-silva, Paolo BellaviteAbstract:Background and Aim Arnica montana L. (Arnica m.) is a popular traditional medicine, used for its therapeutic properties in healing traumas, but little is known about its biological action on tissue formation and repair. This new work tested the effects of Arnica m. homeopathic dilutions on human macrophages, key Cells in tissue defence and repair. Materials and Methods Macrophages derived from the THP-1 Cell Line were differentiated with interleukin-4 to induce a ‘wound-healing’-like phenotype, and treated with various dilutions of Arnica m. centesimal (100 times) dilutions (2c, 3c, 5c, 9c, and 15c) or control solvent for 24 hours. RNA samples from cultured Cells were analysed by real-time quantitative polymerase chain reaction in five separate experiments. Results Arnica montana at the 2c dilution (final concentration of sesquiterpene lactones in Cell culture = 10−8 mol/L) significantly stimulated the expression of three genes which code for regulatory proteins of the extraCellular matrix, namely FN1 (fibronectin 1, % increase of 21.8 ± standard error of the mean 4.6), low-density lipoprotein-receptor-related protein 1 (% increase of 33.4 ± 6.1) and heparan sulphate proteoglycan 2 (% increase of 21.6 ± 9.1). Among these genes, the most quantitatively expressed was FN1. In addition, FN1, unlike other candidate genes, was upregulated in Cells treated with higher dilutions/dynamisations (3c, 5c, and 15c) of Arnica m. Conclusion The results support evidence that the extraCellular matrix is a potential therapeutic target of Arnica m., with positive effects on Cell adhesion and migration during tissue development and healing.
-
Arnica montana Stimulates ExtraCellular Matrix Gene Expression in a Macrophage Cell Line Differentiated to Wound-Healing Phenotype
PloS one, 2016Co-Authors: Marta Marzotto, Clara Bonafini, Debora Olioso, Anna Baruzzi, Laura Bettinetti, Francesca Di Leva, Elisabetta Galbiati, Paolo BellaviteAbstract:Arnica montana (Arnica m.) is used for its purported anti-inflammatory and tissue healing actions after trauma, bruises, or tissue injuries, but its Cellular and molecular mechanisms are largely unknown. This work tested Arnica m. effects on gene expression using an in vitro model of macrophages polarized towards a "wound-healing" phenotype. The monocyte-macrophage human THP-1 Cell Line was cultured and differentiated with phorbol-myristate acetate and Interleukin-4, then exposed for 24h to Arnica m. centesimal (c) dilutions 2c, 3c, 5c, 9c, 15c or Control. Total RNA was isolated and cDNA libraries were sequenced with a NextSeq500 sequencer. Genes with significantly positive (up-regulated) or negative (down-regulated) fold changes were defined as differentially expressed genes (DEGs). A total of 20 DEGs were identified in Arnica m. 2c treated Cells. Of these, 7 genes were up-regulated and 13 were down-regulated. The most significantly up-regulated function concerned 4 genes with a conserved site of epidermal growth factor-like region (p
-
arnica montana stimulates extraCellular matrix gene expression in a macrophage Cell Line differentiated to wound healing phenotype
PLOS ONE, 2016Co-Authors: Marta Marzotto, Clara Bonafini, Debora Olioso, Anna Baruzzi, Laura Bettinetti, Francesca Di Leva, Elisabetta Galbiati, Paolo BellaviteAbstract:Arnica montana (Arnica m.) is used for its purported anti-inflammatory and tissue healing actions after trauma, bruises, or tissue injuries, but its Cellular and molecular mechanisms are largely unknown. This work tested Arnica m. effects on gene expression using an in vitro model of macrophages polarized towards a "wound-healing" phenotype. The monocyte-macrophage human THP-1 Cell Line was cultured and differentiated with phorbol-myristate acetate and Interleukin-4, then exposed for 24h to Arnica m. centesimal (c) dilutions 2c, 3c, 5c, 9c, 15c or Control. Total RNA was isolated and cDNA libraries were sequenced with a NextSeq500 sequencer. Genes with significantly positive (up-regulated) or negative (down-regulated) fold changes were defined as differentially expressed genes (DEGs). A total of 20 DEGs were identified in Arnica m. 2c treated Cells. Of these, 7 genes were up-regulated and 13 were down-regulated. The most significantly up-regulated function concerned 4 genes with a conserved site of epidermal growth factor-like region (p<0.001) and three genes of proteinaceous extraCellular matrix, including heparin sulphate proteoglycan 2 (HSPG2), fibrillin 2 (FBN2), and fibronectin (FN1) (p<0.01). Protein assay confirmed a statistically significant increase of fibronectin production (p<0.05). The down-regulated transcripts derived from mitochondrial genes coding for some components of electron transport chain. The same groups of genes were also regulated by increasing dilutions of Arnica m. (3c, 5c, 9c, 15c), although with a lower effect size. We further tested the healing potential of Arnica m. 2c in a scratch model of wound closure based on the motility of bone marrow-derived macrophages and found evidence of an accelerating effect on Cell migration in this system. The results of this work, taken together, provide new insights into the action of Arnica m. in tissue healing and repair, and identify extraCellular matrix regulation by macrophages as a therapeutic target.
Pascal Preira - One of the best experts on this subject based on the ideXlab platform.
-
the leukocyte stiffening property of plasma in early acute respiratory distress syndrome ards revealed by a microfluidic single Cell study the role of cytokines and protection with antibodies
Critical Care, 2015Co-Authors: Pascal Preira, Jeanmarie Forel, Philippe Robert, Paulin Negre, Martine Biarnespelicot, Francois Xeridat, Pierre Bongrand, Laurent Papazian, Olivier TheodolyAbstract:AbstractBackgroundLeukocyte-mediated pulmonary inflammation is a key pathophysiological mechanism involved in acute respiratory distress syndrome (ARDS). Massive sequestration of leukocytes in the pulmonary microvasculature is a major triggering event of the syndrome. We therefore investigated the potential role of leukocyte stiffness and adhesiveness in the sequestration of leukocytes in microvessels. MethodsThis study was based on in vitro microfluidic assays using patient sera. Cell stiffness was assessed by measuring the entry time (ET) of a single Cell into a microchannel with a 6 × 9–μm cross-section under a constant pressure drop (ΔP = 160 Pa). Primary neutrophils and monocytes, as well as the monocytic THP-1 Cell Line, were used. Cellular adhesiveness to human umbilical vein endothelial Cells was examined using the laminar flow chamber method. We compared the properties of Cells incubated with the sera of healthy volunteers (n = 5), patients presenting with acute cardiogenic pulmonary edema (ACPE; n = 6), and patients with ARDS (n = 22), of whom 13 were classified as having moderate to severe disease and the remaining 9 as having mild disease. ResultsRapid and strong stiffening of primary neutrophils and monocytes was induced within 30 minutes (mean ET >50 seconds) by sera from the ARDS group compared with both the healthy subjects and the ACPE groups (mean ET <1 second) (p < 0.05). Systematic measurements with the THP-1 Cell Line allowed for the establishment of a strong correlation between stiffening and the severity of respiratory status (mean ET 0.82 ± 0.08 seconds for healthy subjects, 1.6 ± 1.0 seconds for ACPE groups, 10.5 ± 6.1 seconds for mild ARDS, and 20.0 ± 8.1 seconds for moderate to severe ARDS; p < 0.05). Stiffening correlated with the cytokines interleukin IL-1β, IL-8, tumor necrosis factor TNF-α, and IL-10 but not with interferon-γ, transforming growth factor-β, IL-6, or IL-17. Strong stiffening was induced by IL-1β, IL-8, and TNF-α but not by IL-10, and incubations with sera and blocking antibodies against IL-1β, IL-8, or TNF-α significantly diminished the stiffening effect of serum. In contrast, the measurements of integrin expression (CD11b, CD11a, CD18, CD49d) and leukocyte–endothelium adhesion showed a weak and slow response after incubation with the sera of patients with ARDS (several hours), suggesting a lesser role of leukocyte adhesiveness compared with leukocyte stiffness in early ARDS. ConclusionsThe leukocyte stiffening induced by cytokines in the sera of patients might play a role in the sequestration of leukocytes in the lung capillary beds during early ARDS. The inhibition of leukocyte stiffening with blocking antibodies might inspire future therapeutic strategies.
-
The leukocyte-stiffening property of plasma in early acute respiratory distress syndrome (ARDS) revealed by a microfluidic single-Cell study: the role of cytokines and protection with antibodies
Critical Care, 2015Co-Authors: Pascal Preira, Jeanmarie Forel, Philippe Robert, Paulin Negre, Francois Xeridat, Pierre Bongrand, Laurent Papazian, Martine Biarnes-pelicot, Olivier TheodolyAbstract:AbstractBackgroundLeukocyte-mediated pulmonary inflammation is a key pathophysiological mechanism involved in acute respiratory distress syndrome (ARDS). Massive sequestration of leukocytes in the pulmonary microvasculature is a major triggering event of the syndrome. We therefore investigated the potential role of leukocyte stiffness and adhesiveness in the sequestration of leukocytes in microvessels. MethodsThis study was based on in vitro microfluidic assays using patient sera. Cell stiffness was assessed by measuring the entry time (ET) of a single Cell into a microchannel with a 6 × 9–μm cross-section under a constant pressure drop (ΔP = 160 Pa). Primary neutrophils and monocytes, as well as the monocytic THP-1 Cell Line, were used. Cellular adhesiveness to human umbilical vein endothelial Cells was examined using the laminar flow chamber method. We compared the properties of Cells incubated with the sera of healthy volunteers (n = 5), patients presenting with acute cardiogenic pulmonary edema (ACPE; n = 6), and patients with ARDS (n = 22), of whom 13 were classified as having moderate to severe disease and the remaining 9 as having mild disease. ResultsRapid and strong stiffening of primary neutrophils and monocytes was induced within 30 minutes (mean ET >50 seconds) by sera from the ARDS group compared with both the healthy subjects and the ACPE groups (mean ET
Pierre Bongrand - One of the best experts on this subject based on the ideXlab platform.
-
the leukocyte stiffening property of plasma in early acute respiratory distress syndrome ards revealed by a microfluidic single Cell study the role of cytokines and protection with antibodies
Critical Care, 2015Co-Authors: Pascal Preira, Jeanmarie Forel, Philippe Robert, Paulin Negre, Martine Biarnespelicot, Francois Xeridat, Pierre Bongrand, Laurent Papazian, Olivier TheodolyAbstract:AbstractBackgroundLeukocyte-mediated pulmonary inflammation is a key pathophysiological mechanism involved in acute respiratory distress syndrome (ARDS). Massive sequestration of leukocytes in the pulmonary microvasculature is a major triggering event of the syndrome. We therefore investigated the potential role of leukocyte stiffness and adhesiveness in the sequestration of leukocytes in microvessels. MethodsThis study was based on in vitro microfluidic assays using patient sera. Cell stiffness was assessed by measuring the entry time (ET) of a single Cell into a microchannel with a 6 × 9–μm cross-section under a constant pressure drop (ΔP = 160 Pa). Primary neutrophils and monocytes, as well as the monocytic THP-1 Cell Line, were used. Cellular adhesiveness to human umbilical vein endothelial Cells was examined using the laminar flow chamber method. We compared the properties of Cells incubated with the sera of healthy volunteers (n = 5), patients presenting with acute cardiogenic pulmonary edema (ACPE; n = 6), and patients with ARDS (n = 22), of whom 13 were classified as having moderate to severe disease and the remaining 9 as having mild disease. ResultsRapid and strong stiffening of primary neutrophils and monocytes was induced within 30 minutes (mean ET >50 seconds) by sera from the ARDS group compared with both the healthy subjects and the ACPE groups (mean ET <1 second) (p < 0.05). Systematic measurements with the THP-1 Cell Line allowed for the establishment of a strong correlation between stiffening and the severity of respiratory status (mean ET 0.82 ± 0.08 seconds for healthy subjects, 1.6 ± 1.0 seconds for ACPE groups, 10.5 ± 6.1 seconds for mild ARDS, and 20.0 ± 8.1 seconds for moderate to severe ARDS; p < 0.05). Stiffening correlated with the cytokines interleukin IL-1β, IL-8, tumor necrosis factor TNF-α, and IL-10 but not with interferon-γ, transforming growth factor-β, IL-6, or IL-17. Strong stiffening was induced by IL-1β, IL-8, and TNF-α but not by IL-10, and incubations with sera and blocking antibodies against IL-1β, IL-8, or TNF-α significantly diminished the stiffening effect of serum. In contrast, the measurements of integrin expression (CD11b, CD11a, CD18, CD49d) and leukocyte–endothelium adhesion showed a weak and slow response after incubation with the sera of patients with ARDS (several hours), suggesting a lesser role of leukocyte adhesiveness compared with leukocyte stiffness in early ARDS. ConclusionsThe leukocyte stiffening induced by cytokines in the sera of patients might play a role in the sequestration of leukocytes in the lung capillary beds during early ARDS. The inhibition of leukocyte stiffening with blocking antibodies might inspire future therapeutic strategies.
-
The leukocyte-stiffening property of plasma in early acute respiratory distress syndrome (ARDS) revealed by a microfluidic single-Cell study: the role of cytokines and protection with antibodies
Critical Care, 2015Co-Authors: Pascal Preira, Jeanmarie Forel, Philippe Robert, Paulin Negre, Francois Xeridat, Pierre Bongrand, Laurent Papazian, Martine Biarnes-pelicot, Olivier TheodolyAbstract:AbstractBackgroundLeukocyte-mediated pulmonary inflammation is a key pathophysiological mechanism involved in acute respiratory distress syndrome (ARDS). Massive sequestration of leukocytes in the pulmonary microvasculature is a major triggering event of the syndrome. We therefore investigated the potential role of leukocyte stiffness and adhesiveness in the sequestration of leukocytes in microvessels. MethodsThis study was based on in vitro microfluidic assays using patient sera. Cell stiffness was assessed by measuring the entry time (ET) of a single Cell into a microchannel with a 6 × 9–μm cross-section under a constant pressure drop (ΔP = 160 Pa). Primary neutrophils and monocytes, as well as the monocytic THP-1 Cell Line, were used. Cellular adhesiveness to human umbilical vein endothelial Cells was examined using the laminar flow chamber method. We compared the properties of Cells incubated with the sera of healthy volunteers (n = 5), patients presenting with acute cardiogenic pulmonary edema (ACPE; n = 6), and patients with ARDS (n = 22), of whom 13 were classified as having moderate to severe disease and the remaining 9 as having mild disease. ResultsRapid and strong stiffening of primary neutrophils and monocytes was induced within 30 minutes (mean ET >50 seconds) by sera from the ARDS group compared with both the healthy subjects and the ACPE groups (mean ET
-
Aspiration of THP1 into a micropipette. Mechanical deformation of monocytic THP-1 Cells: occurrence of two sequential phases with differential sensitivity to metabolic inhibitors
Experimental Biology Online, 1997Co-Authors: Fabienne Richelme, Anne Marie Benoliel, Pierre BongrandAbstract:Blood leukocytes can exhibit extensive morphological changes during their passage through small capillary vessels. The human monocytic THP-1 Cell Line was used to explore the metabolic dependence of these changes in shape. Cells were aspirated into micropipettes for determination of the rate of protrusion formation. They were then released and the kinetics of morphological recovery was studied. Results were consistent with Evans’ model ( Blood 64:1028, 1984) of a viscous liquid droplet surrounded by a tensile membrane. The estimated values of cytoplasmic viscosity and membrane tension were 162 Pa.s and 0.0142 mN/m respectively. The influence of metabolic inhibitors on Cell mechanical behavior was then studied: results strongly suggested that deformation involved two sequential phases. The Cell elongation rate measured during the first 30 s following the onset of aspiration was unaffected by azide, an inhibitor of energy production, and it was about doubled by cytochalasin D, a microfilament inhibitor, and colchicine, a microtubule inhibitor. However, during the following 2 min, deformation was almost abolished in Cells treated with azide and cytochalasin D, whereas the protrusion of control Cells exhibited an approximately threefold increase in length. It is concluded that, although Cells seemed to deform as passive objects, active metabolic processes were required to allow extensive morphological changes triggered by external forces.
-
Mechanical deformation of monocytic THP-1 Cells : occurrence of two seqential phases with differential sensitivity to metabolic inhibitors
Experimental Biology Online - EBO, 1997Co-Authors: Pierre Bongrand, Anne Marie Benoliel, Fabienne RichelmeAbstract:Blood leukocytes can exhibit extensive morphological changes during their passage through small capillary vessels. The human monocytic THP-1 Cell Line was used to explore the metabolic dependence of these shape changes. Cells were aspirated into micropipettes for determination of the rate of protrusion formation. They were then released and the kinetics of morphological recovery was studied. Results were consistent with Evans' model (Blood, 64 : 1028, 1984) of a viscous liquid droplet surrounded by a tensile membrane. The estimated values of cytoplasmic viscosity and membrane tension were 162 Pa.s and 0.0142 milLinewton/m respectively. The influence of metabolic inhibitors on Cell mechanical behaviour was then studied : results strongly suggested that deformation involved two sequential phases. The Cell elongation rate measured during the first 30 seconds following the onset of aspiration was unaffected by azide, an inhibitor of energy production, and it was about doubled by cytochalasin D, a microfilament inhibitor, and colchicine, a microtubule inhibitor. However, during the following two minutes, deformation was almost abolished in Cells treated with azide and cytochalasin D, whereas the protrusion of control Cells exhibited about threefold length increase. It is concluded that, although Cells seemed to deform as passive objects, active metabolic processes were required to allow extensive morphological changes triggered by external forces.
Saadia Kerdine-römer - One of the best experts on this subject based on the ideXlab platform.
-
The THP-1 Cell toolbox: a new concept integrating the key events of skin sensitization
Archives of Toxicology, 2019Co-Authors: Elodie Clouet, Marc Pallardy, Rami Bechara, Chloé Raffalli, Marie-hélène Damiens, Hervé Groux, Pierre-jacques Ferret, Saadia Kerdine-römerAbstract:According to the current scientific consensus, one in vitro test is insufficient to cover the key events (KE) defined by the adverse outcome pathway (AOP) for skin sensitization. To address this issue we combined different end points in the same Cell Line to cover all KEs defined by the skin sensitization AOP. Since dendritic Cells (DC) play a key role in the sensitization phase leading to the development of allergic contact dermatitis (ACD), we used THP-1 Cells as a surrogate for DC. We measured ROS production and GSH depletion for KE1 (binding to proteins), Nrf2 activation pathway and gene expressions for KE2 (keratinocyte response), phenotype modifications using Cell-surface markers and cytokine production for KE3 (DC activation), and T-Cell proliferation for KE4 (T-Cell activation). These measurements were performed using the THP-1 Cell Line and an original THP-1/T-Cell co-culture system following exposure to a variety of chemicals, including irritant, non-sensitizers, and chemicals sensitizers (pro/prehaptens). Results showed that treatment with sensitizers such as cinnamaldehyde (100 µM) or methylisothiazolinone (150 µM) was able to trigger the three main key events (KE1, KE2, and KE3) of the sensitization phase of ACD in THP-1 Cells. In addition, all sensitizers were able to induce T lymphocyte proliferation (KE4), while non-sensitizers and irritants did not. Our study shows for the first time that addressing the four main KE of skin sensitization AOP in a single Cell Line is an achievable task.
-
Editor’s Highlight: Fragrance Allergens Linalool and Limonene Allylic Hydroperoxides in Skin Allergy: Mechanisms of Action Focusing on Transcription Factor Nrf2
Toxicological Sciences, 2018Co-Authors: Chloé Raffalli, Marc Pallardy, Elodie Clouet, Marie-hélène Damiens, Pierre-jacques Ferret, Salen Kuresepi, Jean-pierre Lepoittevin, Elena Giménez-arnau, Saadia Kerdine-römerAbstract:Allergic contact dermatitis is regarded as the most frequent expression of immunotoxicity in humans. Many odorant terpenes commonly used in fragrance compositions are considered as weak skin sensitizers, whereas some of their autoxidation products, allylic hydroperoxides, are classified as strong sensitizers according to the local lymph node assay. However, the mechanism of their effects on the immune system remains unclear. Since dendritic Cells play a key role in allergic contact dermatitis, we studied their activation by the frequently used linalool (LINA) and limonene (LIMO), and their respective sensitizing allylic hydroperoxides (LINA-OOH, LIMO-OOH). The THP-1 Cell-Line was used as a surrogate for dendritic Cells, the model currently employed in the validated h-CLAT in vitro test. Our data showed that allylic hydroperoxides behave differently. Both LINA-OOH and LIMO-OOH oxidized Cell surface thiols 30 min after stimulation. However, the oxidative stress induced by LINA-OOH was stronger, with a higher decreased GSH/GSSG ratio and a stronger reactive species production. Moreover, LINA-OOH induced a stronger Nrf2 accumulation in correlation with nqo1 and ho-1 gene expression, 2 Nrf2 target genes. Regarding signaling pathways involved in these effects, P38 mitogen-activated protein kinase and P-ERK were activated in response to LINA-OOH but not with LIMO-OOH. CD54 and CD86 were induced 24-h postexposure. In contrast, LINA and LIMO did not modify THP-1 phenotype. This work underlies that autoxidation forming allylic hydroperoxide (ROOH) does not lead to equal chemical reactivity since LINA-OOH appears to be a stronger activator than LIMO-OOH, in regard to oxidative stress and Nrf2 pathway activation.
