Kinetics of monocyte subpopulations during experimental cerebral malaria and its resolution in a model of late chloroquine treatment.

Cerebral malaria (CM) is one of the most severe forms of malaria and is a neuropathology that can lead to death. Monocytes have been shown to accumulate in the brain microvasculature at the onset of neurological symptoms during CM. Monocytes have a remarkable ability to adapt their function to their microenvironment from pro-inflammatory to resolving activities. This study aimed to describe the behavior of monocyte subpopulations during infection and its resolution. C57BL/6 mice were infected with the Plasmodium berghei ANKA strain and treated or not with chloroquine (CQ) on the first day of the onset of neurological symptoms (day 6) for 4 days and followed until day 12 to mimic neuroinflammation and its resolution during experimental CM. Ly6C monocyte subpopulations were identified by flow cytometry of cells from the spleen, peripheral blood, and brain and then quantified and characterized at different time points. In the brain, the Ly6Cint and Ly6Clow monocytes were associated with neuroinflammation, while Ly6Chi and Ly6Cint were mobilized from the peripheral blood to the brain for resolution. During neuroinflammation, CD36 and CD163 were both involved via splenic monocytes, whereas our results suggest that the low CD36 expression in the brain during the neuroinflammation phase was due to degradation. The resolution phase was characterized by increased expressions of CD36 and CD163 in blood Ly6Clow monocytes, a higher expression of CD36 in the microglia, and restored high expression levels of CD163 in Ly6Chi monocytes localized in the brain. Thus, our results suggest that increasing the expressions of CD36 and CD163 specifically in the brain during the neuroinflammatory phase contributes to its resolution.

Topical Aspirin Administration Improves Cutaneous Wound Healing in Diabetic Mice Through a Phenotypic Switch of Wound Macrophages Toward an Anti-inflammatory and Proresolutive Profile Characterized by LXA4 Release.

Patients with diabetes present a persistent inflammatory process, leading to impaired wound healing. Since nonhealing diabetic wound management shows limited results, the introduction of advanced therapies targeting and correcting the inflammatory status of macrophages in chronic wounds could be an effective therapeutic strategy to stop the sustained inflammation and to return to a healing state. In an excisional skin injury in a diet-induced diabetic murine model, we demonstrate that topical administration of low-dose aspirin (36 µg/wound/day) improves cutaneous wound healing by increasing wound closure through the promotion of the inflammation resolution program of macrophages. This treatment increased efferocytosis of wound macrophages from aspirin-treated diabetic mice compared with untreated diabetic mice. We also show that aspirin treatment of high-fat-fed mice oriented the phenotype of wound macrophages toward an anti-inflammatory and proresolutive profile characterized by a decrease of LTB4 production. The use of diabetic mice deficient for 5-LOX or 12/15-LOX demonstrated that these two enzymes of acid arachidonic metabolism are essential for the beneficial effect of aspirin on wound healing. Thus, aspirin treatment modified the balance between pro- and anti-inflammatory eicosanoids by promoting the synthesis of proresolving LXA4 through 5-LOX, LTA4, 12/15-LOX signaling. In conclusion, the restoration of an anti-inflammatory and proresolutive phenotype of wound macrophages by the topical administration of low-dose aspirin represents a promising therapeutic approach in chronic wounds.

Differential immunomodulatory effects of six pesticides of different chemical classes on human monocyte-derived macrophage functions.

Exposure to pesticides through eyes, skin, ingestion and inhalation may affects human health by interfering with immune cells, such as macrophages. We evaluated, in vitro, the effect of six pesticides widely used in apple arboriculture on the functions of human monocyte-derived macrophages (hMDMs). hMDMs were cultured for 4 or 24 h with or without pesticides (0.01, 0.1, 1, 10 µmol.L-1). We showed that chlorpyrifos, thiacloprid, thiophanate, boscalid, and captan had little toxic effect at the tested concentrations, while dithianon had low-cytotoxicity at 10 µmol.L-1. While boscalid showed no effect on hMDMs function, thiophanate (0.01 µmol.L-1) stimulated with TPA and thiacloprid (1, 10 µmol.L-1) stimulated with zymosan activated ROS production. Chlorpyrifos, dithianon, and captan inhibited ROS production and TNF-α, IL-1ß pro-inflammatory cytokines. We established that dithianon (0.01-1 µmol.L-1) and captan (0.1, 1 µmol.L-1) induced mRNA expression of NQO1 and HMOX1 antioxidant enzymes. Dithianon also induced the mRNA expression of catalase, superoxide dismutase-2 at 10 µmol.L-1. Together, these results show that exposure to chlorpyrifos, dithianon, and captan induce immunomodulatory effects that may influence the disease fighting properties of monocytes/macrophages while pesticides such as thiacloprid, thiophanate and boscalid have little influence.

Murlentamab, a Low Fucosylated Anti-Müllerian Hormone Type II Receptor (AMHRII) Antibody, Exhibits Anti-Tumor Activity through Tumor-Associated Macrophage Reprogrammation and T Cell Activation.

AMHRII, the anti-Müllerian hormone receptor, is selectively expressed in normal sexual organs but is also re-expressed in gynecologic cancers. Hence, we developed murlentamab, a humanized glyco-engineered anti-AMHRII monoclonal antibody currently in clinical trial. Low-fucosylated antibodies are known to increase the antibody-dependent cell-mediated cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) potency of effector cells, but some preliminary results suggest a more global murlentamab-dependent activation of the immune system. In this context, we demonstrate here that the murlentamab opsonization of AMHRII-expressing ovarian tumor cells, in the presence of unstimulated- or tumor-associated macrophage (TAM)-like macrophages, significantly promotes macrophage-mediated ADCC and shifts the whole microenvironment towards a pro-inflammatory and anti-tumoral status, thus triggering anti-tumor activity. We also report that murlentamab orients both unstimulated- and TAM-like macrophages to an M1-like phenotype characterized by a strong expression of co-stimulation markers, pro-inflammatory cytokines and chemokines, favoring T cell recruitment and activation. Moreover, we show that murlentamab treatment shifts CD4+ Th1/Th2 balance towards a Th1 response and activates CD8+ T cells. Altogether, these results suggest that murlentamab, through naïve macrophage orientation and TAM reprogrammation, stimulates the anti-tumor adaptive immune response. Those mechanisms might contribute to the sustained clinical benefit observed in advanced cancer patients treated with murlentamab. Finally, the enhanced murlentamab activity in combination with pembrolizumab opens new therapeutic perspectives.

Comparative study of the effects of ziram and disulfiram on human monocyte-derived macrophage functions and polarization: involvement of zinc.

Ziram, a zinc dithiocarbamate is widely used worldwide as a fungicide in agriculture. In order to investigate ziram-induced changes in macrophage functions and polarization, human monocytes-derived macrophages in culture were treated with ziram at 0.01-10 µmol.L-1 for 4-24 h. To characterize zinc involvement in these changes, we also determined the effects of disulfiram alone (dithiocarbamate without zinc) or in co-incubation with ZnSO4. We have shown that ziram and disulfiram at 0.01 µmol.L-1 increased zymosan phagocytosis. In contrast, ziram at 10 µmol.L-1 completely inhibited this phagocytic process, the oxidative burst triggered by zymosan and the production of TNF-α, IL-1ß, IL-6, and CCL2 triggered by LPS. Disulfiram had the same effects on these macrophages functions only when combined with zinc (10 µmol.L-1). In contrast, at 10 µmol.L-1 ziram and zinc associated-disulfiram induced expression of several antioxidants genes HMOX1, SOD2, and catalase, which could suggest the induction of oxidative stress. This oxidative stress could be involved in the increase in late apoptosis induced by ziram (10 µmol.L-1) and zinc associated-disulfiram. Concerning gene expression profiles of membrane markers of macrophage polarization, ziram at 10 µmol.L-1 had two opposite effects. It inhibited the gene expression of M2 markers (CD36, CD163) in the same way as the disulfiram-zinc co-treatment. Conversely, ziram induced gene expression of other M2 markers CD209, CD11b, and CD16 in the same way as treatment with zinc alone. Disulfiram-zinc association had no significant effects on these markers. These results taken together show that ziram via zinc modulates macrophages to M2-like anti-inflammatory phenotype which is often associated with various diseases.

Divergent Roles for Macrophage C-type Lectin Receptors, Dectin-1 and Mannose Receptors, in the Intestinal Inflammatory Response.

Colonic macrophages are considered to be major effectors of inflammatory bowel diseases (IBDs) and the control of gut inflammation through C-type lectin receptors is an emerging concept. We show that during colitis, the loss of dectin-1 on myeloid cells prevents intestinal inflammation, while the lack of mannose receptor (MR) exacerbates it. A marked increase in dectin-1 expression in dextran sulfate sodium (DSS)-exposed MR-deficient mice supports the critical contribution of dectin-1 to colitis outcome. Dectin-1 is crucial for Ly6ChighCCR2high monocyte population enrichment in the blood and their recruitment to inflamed colon as precursors of inflammatory macrophages. Dectin-1 also promotes inflammasome-dependent interleukin-1ß (IL-1ß) secretion through leukotriene B4 production. Interestingly, colonic inflammation is associated with a concomitant overexpression of dectin-1/CCL2/LTA4H and downregulation of MR on macrophages from IBD patients. Thus, MR and dectin-1 on macrophages are important mucosal inflammatory regulators that contribute to the intestinal inflammation.

Changes in monocyte subsets are associated with clinical outcomes in severe malarial anaemia and cerebral malaria.

Monocytes are plastic heterogeneous immune cells involved in host-parasite interactions critical for malaria pathogenesis. Human monocytes have been subdivided into three populations based on surface expression of CD14 and CD16. We hypothesised that proportions and phenotypes of circulating monocyte subsets can be markers of severity or fatality in children with malaria. To address this question, we compared monocytes sampled in children with uncomplicated malaria, severe malarial anaemia, or cerebral malaria. Flow cytometry was used to distinguish and phenotype monocyte subsets through CD14, CD16, CD36 and TLR2 expression. Data were first analysed by univariate analysis to evaluate their link to severity and death. Second, multinomial logistic regression was used to measure the specific effect of monocyte proportions and phenotypes on severity and death, after adjustments for other variables unrelated to monocytes. Multivariate analysis demonstrated that decreased percentages of non-classical monocytes were associated with death, suggesting that this monocyte subset has a role in resolving malaria. Using univariate analysis, we also showed that the role of non-classical monocytes involves a mostly anti-inflammatory profile and the expression of CD16. Further studies are needed to decipher the functions of this sub-population during severe malaria episodes, and understand the underlying mechanisms.

IL13-Mediated Dectin-1 and Mannose Receptor Overexpression Promotes Macrophage Antitumor Activities through Recognition of Sialylated Tumor Cells.

Macrophage-mediated cytotoxicity is controlled by surface receptor expression and activation. Despite the numerous studies documenting the role of macrophage C-type lectin receptors (CLR) in pathogen elimination, little is known about their contribution to antitumor responses. Here, we report that IL13 inhibits T-cell lymphoma and ovarian adenocarcinoma development in tumor-bearing mice through the conversion of tumor-supporting macrophages to cytotoxic effectors, characterized by a CLR signature composed of dectin-1 and mannose receptor (MR). We show that dectin-1 and MR are critical for the recognition of tumor cells through sialic acid-specific glycan structure on their surface and for the subsequent activation of macrophage tumoricidal response. Finally, we validated that IL13 antitumor effect mediated by dectin-1 and MR overexpression on macrophages can extend to various types of human tumors. Therefore, these results identify these CLRs as potential targets to promote macrophage antitumor response and represent an attractive approach to elicit tumor-associated macrophage tumoricidal properties.

A digest of capillary electrophoretic methods applied to lipid analyzes.

Lipids are naturally occurring organic compounds that can be classified into a number of types based on their solubility in nonpolar organic solvents, and are generally insoluble in water. The great structural variety of these various types of lipids has led them to be components of many different biological substances such as oils, waxes, cellular membranes, tissues and biological fluids. The use of capillary electrophoresis (CE) for the study of lipids during the past 30 years has been relatively rare when compared to its use for other classes of biomolecules, primarily due to their insolubility in water. However, a number of interesting studies have been conducted, and as part of this review, we will present the different approaches that were used, which mainly consist of micellar kinetic chromatography and non-aqueous CE. The main advantages of the use of these techniques compared to GC is the very simple sample preparation that is required and, compared to LC, the very robust and quick separations that can be obtained. In this review, we present the various methods that have been reported in the literature that have been used for the study of fatty acids, phospholipids, glycerides, eicosanoids and sterols, with the inclusion of various tables presenting descriptions of the CE methods used as well as the methods of detection, including UV absorbance, fluorescence, mass spectrometry, and conductivity. This review aims to demonstrate that CE can be easily used for the analysis of lipids.

Opioids prevent regeneration in adult mammals through inhibition of ROS production.

Inhibition of regeneration and induction of tissue fibrosis are classic outcomes of tissue repair in adult mammals. Here, using a newly developed model of regeneration in adult mammals i.e. regeneration after massive resection of an inguinal fat pad, we demonstrate that both endogenous and exogenous opioids prevent tissue regeneration in adults, by inhibiting the early production of reactive oxygen species (ROS) that generally occurs after lesion and is required for regeneration. These effects can be overcome and regeneration induced by the use of an opioid antagonist. The results obtained in both our new model and the gold standard adult zebrafish demonstrate that this mechanism can be considered as a general paradigm in vertebrates. This work clearly demonstrates that ROS is required for tissue regeneration in adult mammals and shows the deleterious effect of opioids on tissue regeneration through the control of this ROS production. It thus raises questions about opioid-based analgesia in perioperative care.

Targeted Magnetic Intra-Lysosomal Hyperthermia produces lysosomal reactive oxygen species and causes Caspase-1 dependent cell death.

Therapeutic strategies using drugs which cause Lysosomal Cell Death have been proposed for eradication of resistant cancer cells. In this context, nanotherapy based on Magnetic Intra-Lysosomal Hyperthermia (MILH) generated by magnetic nanoparticles (MNPs) that are grafted with ligands of receptors overexpressed in tumors appears to be a very promising therapeutic option. However, mechanisms whereby MILH induces cell death are still elusive. Herein, using Gastrin-grafted MNPs specifically delivered to lysosomes of tumor cells from different cancers, we provide evidences that MILH causes cell death through a non-apoptotic signaling pathway. The mechanism of cell death involves a local temperature elevation at the nanoparticle periphery which enhances the production of reactive oxygen species through the lysosomal Fenton reaction. Subsequently, MILH induces lipid peroxidation, lysosomal membrane permeabilization and leakage of lysosomal enzymes into the cytosol, including Cathepsin-B which activates Caspase-1 but not apoptotic Caspase-3. These data highlight the clear potential of MILH for the eradication of tumors overexpressing receptors.

P17, an Original Host Defense Peptide from Ant Venom, Promotes Antifungal Activities of Macrophages through the Induction of C-Type Lectin Receptors Dependent on LTB4-Mediated PPARγ Activation.

Despite the growing knowledge with regard to the immunomodulatory properties of host defense peptides, their impact on macrophage differentiation and on its associated microbicidal functions is still poorly understood. Here, we demonstrated that the P17, a new cationic antimicrobial peptide from ant venom, induces an alternative phenotype of human monocyte-derived macrophages (h-MDMs). This phenotype is characterized by a C-type lectin receptors (CLRs) signature composed of mannose receptor (MR) and Dectin-1 expression. Concomitantly, this activation is associated to an inflammatory profile characterized by reactive oxygen species (ROS), interleukin (IL)-1ß, and TNF-α release. P17-activated h-MDMs exhibit an improved capacity to recognize and to engulf Candida albicans through the overexpression both of MR and Dectin-1. This upregulation requires arachidonic acid (AA) mobilization and the activation of peroxisome proliferator-activated receptor gamma (PPARγ) nuclear receptor through the leukotriene B4 (LTB4) production. AA/LTB4/PPARγ/Dectin-1-MR signaling pathway is crucial for P17-mediated anti-fungal activity of h-MDMs, as indicated by the fact that the activation of this axis by P17 triggered ROS production and inflammasome-dependent IL-1ß release. Moreover, we showed that the increased anti-fungal immune response of h-MDMs by P17 was dependent on intracellular calcium mobilization triggered by the interaction of P17 with pertussis toxin-sensitive G-protein-coupled receptors on h-MDMs. Finally, we also demonstrated that P17-treated mice infected with C. albicans develop less severe gastrointestinal infection related to a higher efficiency of their macrophages to engulf Candida, to produce ROS and IL-1ß and to kill the yeasts. Altogether, these results identify P17 as an original activator of the fungicidal response of macrophages that acts upstream PPARγ/CLRs axis and offer new immunomodulatory therapeutic perspectives in the field of infectious diseases.

Biochemical and biophysical combined study of bicarinalin, an ant venom antimicrobial peptide.

We have recently characterized bicarinalin as the most abundant peptide from the venom of the ant Tetramorium bicarinatum. This antimicrobial peptide is active against Staphylococcus and Enterobacteriaceae. To further investigate the antimicrobial properties of this cationic and cysteine-free peptide, we have studied its antibacterial, antifungal and antiparasitic activities on a large array of microorganisms. Bicarinalin was active against fifteen microorganisms with minimal inhibitory concentrations ranging from 2 and 25µmolL(-1). Cronobacter sakazakii, Salmonella enterica, Candida albicans, Aspergilus niger and Saccharomyces cerevisiae were particularly susceptible to this novel antimicrobial peptide. Resistant strains of Staphylococcus aureus, Pseudomonas aeruginosa and C. albicans were as susceptible as the canonical strains. Interestingly, bicarinalin was also active against the parasite Leishmania infantum with a minimal inhibitory concentrations of 2µmolL(-1). The bicarinalin pre-propeptide cDNA sequence has been determined using a combination of degenerated primers with RACE PCR strategy. Interestingly, the N-terminal domain of bicarinalin pre-propeptide exhibited sequence similarity with the pilosulin antimicrobial peptide family previously described in the Myrmecia venoms. Moreover, using SYTOX green uptake assay, we showed that, for all the tested microorganisms, bicarinalin acted through a membrane permeabilization mechanism. Two dimensional-NMR experiments showed that bicarinalin displayed a 10 residue-long α-helical structure flanked by two N- and C-terminal disordered regions. This partially amphipathic helix may explain the membrane permeabilization mechanism of bicarinalin observed in this study. Finally, therapeutic value of bicarinalin was highlighted by its low cytotoxicity against human lymphocytes at bactericidal concentrations and its long half-life in human serum which was around 15h.

Nrf2-driven CD36 and HO-1 gene expression in circulating monocytes correlates with favourable clinical outcome in pregnancy-associated malaria.

BACKGROUND: Pregnancy-associated malaria (PAM) constitutes one of the most severe forms of malaria infection leading to fetal growth restriction and high risk of infant death. The severity of the pathology is largely attributed to the recruitment of monocytes and macrophages in the placenta which is evidenced by dysregulated inflammation found in placental blood. Importantly, CD36(+) monocytes/macrophages are also thought to participate in the tight control of the pro- and anti-inflammatory responses following Plasmodium detection through elimination of apoptotic cells and malaria-infected erythrocytes, internalization and recycling of oxidized forms of low-density lipoprotein and collaboration with TLR2 in pro-inflammatory response. Interestingly, previous work demonstrated that CD36 expression was upregulated on inflammatory macrophages following stimulation of the Nrf2 transcription factor, whilst the PPARγ pathway was inhibited and non-functional in the same inflammatory conditions. This current study examined the possible role of Nrf2-driven gene expression, CD36 and Haem-Oxygenase-1 (HO-1), in PAM clinical outcomes. METHODS: Clinical data and biological samples including peripheral blood mononuclear cells were collected from 27 women presenting PAM. Polychromatic flow cytometry was used to characterize innate immune cell subpopulations and quantify CD36 protein expression level on monocytes. mRNA levels of CD36, PPARγ, Nrf2 and HO-1 were determined by qPCR and related to clinical outcomes. Finally, the capacity of monocytes to modulate CD36 expression upon rosiglitazone or sulforaphane treatment, two respective PPARγ or Nrf2 activators, was also investigated. RESULTS: The CD36 receptor, mostly expressed by CD14(+) circulating monocytes, statistically correlated with increased infant birth weights. Interestingly, mRNA levels of the transcription factor Nrf2 and the enzyme HO-1 also correlated with lower parasitaemia and increased infant birth weight, while PPARγ mRNA levels did not. Finally, monocytes isolated from low infant birth weight pregnant women were capable of up-regulating CD36 via the Nrf2 pathway ex vivo. CONCLUSIONS: Altogether these results suggest that Nrf2-driven CD36 and HO-1 expression on innate immune cells could contribute to a protective and detoxifying mechanism during PAM. More powered and mechanistical studies are however needed to strengthen the conclusions of this study.

LRH-1 mediates anti-inflammatory and antifungal phenotype of IL-13-activated macrophages through the PPARγ ligand synthesis.

Liver receptor homologue-1 (LRH-1) is a nuclear receptor involved in the repression of inflammatory processes in the hepatointestinal tract. Here we report that LRH-1 is expressed in macrophages and induced by the Th2 cytokine IL-13 via a mechanism involving STAT6. We show that loss-of-function of LRH-1 in macrophages impedes IL-13-induced macrophage polarization due to impaired generation of 15-HETE PPARγ ligands. The incapacity to generate 15-HETE metabolites is at least partially caused by the compromised regulation of CYP1A1 and CYP1B1. Mice with LRH-1-deficient macrophages are, furthermore, highly susceptible to gastrointestinal and systemic Candida albicans infection. Altogether, these results identify LRH-1 as a critical component of the anti-inflammatory and fungicidal response of alternatively activated macrophages that acts upstream from the IL-13-induced 15-HETE/PPARγ axis.

Specific macrophage subtypes influence the progression of rhabdomyolysis-induced kidney injury.

Rhabdomyolysis can be life threatening if complicated by AKI. Macrophage infiltration has been observed in rat kidneys after glycerol-induced rhabdomyolysis, but the role of macrophages in rhabdomyolysis-induced AKI remains unknown. Here, in a patient diagnosed with rhabdomyolysis, we detected substantial macrophage infiltration in the kidney. In a mouse model of rhabdomyolysis-induced AKI, diverse renal macrophage phenotypes were observed depending on the stage of the disease. Two days after rhabdomyolysis, F4/80(low)CD11b(high)Ly6b(high)CD206(low) kidney macrophages were dominant, whereas by day 8, F4/80(high)CD11b(+)Ly6b(low)CD206(high) cells became the most abundant. Single-cell gene expression analyses of FACS-sorted macrophages revealed that these subpopulations were heterogeneous and that individual cells simultaneously expressed both M1 and M2 markers. Liposomal clodronate-mediated macrophage depletion significantly reduced the early infiltration of F4/80(low)CD11b(high)Ly6b(high)CD206(low) macrophages. Furthermore, transcriptionally regulated targets potentially involved in disease progression, including fibronectin, collagen III, and chemoattractants that were identified via single-cell analysis, were verified as macrophage-dependent in situ. In vitro, myoglobin treatment induced proximal tubular cells to secrete chemoattractants and macrophages to express proinflammatory markers. At day 30, liposomal clodronate-mediated macrophage depletion reduced fibrosis and improved both kidney repair and mouse survival. Seven months after rhabdomyolysis, histologic lesions were still present but were substantially reduced with prior depletion of macrophages. These results suggest an important role for macrophages in rhabdomyolysis-induced AKI progression and advocate the utility of long-term follow-up for patients with this disease.

Leishmanicidal compounds and potent PPARγ activators from Renealmia thyrsoidea (Ruiz & Pav.) Poepp. & Endl.

ETHNOPHARMACOLOGICAL RELEVANCE: Leaves and rhizomes of Renealmia thyrsoidea (Ruiz & Pav.) Poepp. & Endl. traditionally used in the Yanesha pharmacopoeia to treat skin infections such as leishmaniasis ulcers, or to reduce fever were chemically investigated to identify leishmanicidal compounds, as well as PPARγ activators. METHODS: Compounds were isolated through a bioassay-guided fractionation and their structures were determined via detailed spectral analysis. The viability of Leishmania amazonensis axenic amastigotes was assessed by the reduction of tetrazolium salt (MTT), the cytotoxicity on macrophage was evaluated using trypan blue dye exclusion method, while the percentage of infected macrophages was determined microscopically in the intracellular macrophage-infected assay. The CD36, mannose receptor (MR) and dectin-1 mRNA expression on human monocytes-derived macrophages was evaluated by quantitative real-time PCR. RESULTS: Six sesquiterpenes (1-6), one dihydrobenzofuranone (7) and four flavonoids (8-11) were isolated from the leaves. Alongside, two flavonoids (12-13) and five diarylheptanoids (14-18) were identified in the rhizomes. Leishmanicidal activity against Leishmania amazonensis axenic amastigotes was evaluated for all compounds. Compounds 6, 7, and 11, isolated from the leaves, showed to be the most active derivatives. Diarylheptanoids 14-18 were also screened for their ability to activate PPARγ nuclear receptor in macrophages. Compounds 17 and 18 bearing a Michael acceptor moiety strongly increased the expression of PPARγ target genes such as CD36, Dectin-1 and mannose receptor (MR), thus revealing interesting immunomodulatory properties. CONCLUSIONS: Phytochemical investigation of Renealmia thyrsoidea has led to the isolation of leishmanicidal compounds from the leaves and potent PPARγ activators from the rhizomes. These results are in agreement with the traditional uses of the different parts of Renealmia thyrsoidea.

Protolichesterinic acid derivatives: α-methylene-γ-lactones as potent dual activators of PPARγ and Nrf2 transcriptional factors.

PPARγ and Nrf2 are important transcriptional factors involved in many signaling pathways, especially in the anti-infectious response of macrophages. Compounds bearing a Michael acceptor moiety are well known to activate such transcriptional factors, we thus evaluated the potency of α,ß-unsaturated lactones synthesized using fluorous phase organic synthesis. Compounds were first screened for their cytotoxicity in order to select lactones for PPARγ and Nrf2 activation evaluation. Among them, two α-methylene-γ-lactones were identified as potent dual activators of PPARγ and Nrf2 in macrophages.

Targeting a G-protein-coupled receptor overexpressed in endocrine tumors by magnetic nanoparticles to induce cell death.

Nanotherapy using targeted magnetic nanoparticles grafted with peptidic ligands of receptors overexpressed in cancers is a promising therapeutic strategy. However, nanoconjugation of peptides can dramatically affect their properties with respect to receptor recognition, mechanism of internalization, intracellular trafficking, and fate. Furthermore, investigations are needed to better understand the mechanism whereby application of an alternating magnetic field to cells containing targeted nanoparticles induces cell death. Here, we designed a nanoplatform (termed MG-IONP-DY647) composed of an iron oxide nanocrystal decorated with a ligand of a G-protein coupled receptor, the cholecystokinin-2 receptor (CCK2R) that is overexpressed in several malignant cancers. MG-IONP-DY647 did not stimulate inflammasome of Raw 264.7 macrophages. They recognized cells expressing CCK2R with a high specificity, subsequently internalized via a mechanism involving recruitment of ß-arrestins, clathrin-coated pits, and dynamin and were directed to lysosomes. Binding and internalization of MG-IONP-DY647 were dependent on the density of the ligand at the nanoparticle surface and were slowed down relative to free ligand. Trafficking of CCK2R internalized with the nanoparticles was slightly modified relative to CCK2R internalized in response to free ligand. Application of an alternating magnetic field to cells containing MG-IONP-DY647 induced apoptosis and cell death through a lysosomal death pathway, demonstrating that cell death is triggered even though nanoparticles of low thermal power are internalized in minute amounts by the cells. Together with pioneer findings using iron oxide nanoparticles targeting tumoral cells expressing epidermal growth factor receptor, these data represent a solid basis for future studies aiming at establishing the proof-of-concept of nanotherapy of cancers using ligand-grafted magnetic nanoparticles specifically internalized via cell surface receptors.

Aspergillus sensitization or carriage in cystic fibrosis patients.

BACKGROUND: Aspergillus fumigatus (Af) sensitization and persistent carriage are deleterious to lung function, but no consensus has been reached defining these medical entities. This work aimed to identify possible predictive factors for patients who become sensitized to Af, compared with a control group of non-sensitized Af carriers. METHODS: Between 1995 and 2007, 117 pediatric patients were evaluated. Demographic data, CFTR gene mutations, body mass index and FEV1 were recorded. The presence of Af in sputum, the levels of Af-precipitin, total IgE (t-IgE) and specific IgE to Af (Af-IgE) were determined. Patients were divided into 2 groups: (1) "sensitization": level of Af-IgE > 0.35 IU/mL with t-IgE level < 500 IU/mL and (2) "persistent or transient carriage": Af-IgE level ≤ 0.35 IU/mL with either an Af transient or persistent positive culture. A survival analysis was performed with the appearance of Af-IgE in serum as an outcome variable. RESULTS: Severe mutation (hazard ratio = 3.2), FEV1 baseline over 70% of theoretical value (hazard ratio = 4.9), absence of Pa colonization, catalase activity and previous azithromycin administration (hazard ratio = 9.8, 4.1 and 1.9, respectively) were predictive factors for sensitization. We propose a timeline of the biological events and a tree diagram for risk calculation. CONCLUSIONS: Two profiles of cystic fibrosis patients can be envisaged: (1) patients with nonsevere mutation but low FEV1 baselines are becoming colonized with Af or (2) patients with high FEV1 baselines who present with severe mutation are more susceptible to the Af sensitization and then to the presentation of an allergic bronchopulmonary aspergillosis event.