scholarly journals Functional and signaling characterization of the neutrophil FPR2 selective agonist Act-389949

2019 ◽  
Author(s):  
Simon Lind ◽  
Martina Sundqvist ◽  
Rikard Holmdahl ◽  
Claes Dahlgren ◽  
Huamei Forsman ◽  
...  

AbstractDespite the steadily increased numbers of formyl peptide receptor (FPR) ligands identified over the years, few have been characterized in studies using animal disease models and even less have entered clinical trials in human subjects. A small-molecule compound, Act-389949, was however recently tested in a phase I clinical trial and found to be safe and well tolerated in healthy human subjects. The desired anti-inflammatory property of Act-389949 was proposed to be mediated through FPR2, one of the FPRs expressed in neutrophils, but no basic characterization was included in the study. To gain more insights into FPR2 recognition of this first-in-class compound for future utility of the agonist, we have in this study determined the receptor preference and down-stream signaling characteristics induced by Act-389949 in human blood neutrophils isolated from healthy donors. Our data demonstrate that Act-389949 is an agonist for FPR2 that triggers functional/signaling repertoires comparable to what has been earlier described for other FPR2 agonists, including neutrophil chemotaxis, granule mobilization and activation of the NADPH-oxidase. In fact, Act-389949 was found to be as potent as the prototype FPR2 peptide agonist WKYMVM and had the advantage of being resistant to oxidation by the MPO-H2O2-halide derived oxidants, as compared to the sensitive WKYMVM. The down-stream signals generated by Act-389949 include an FPR2-dependent and Gαq-independent transient rise in intracellular Ca2+ and recruitment of β-arrestin. In summary, our data show that Act-389949 serves as an excellent tool-compound for further dissection of FPR2-regulated activities in vitro and in vivo. Potent and stable FPR ligands such as Act-389949 may therefore be used to develop the next generation of FPR signaling regulating anti-inflammatory therapeutics.

Blood ◽  
2010 ◽  
Vol 116 (20) ◽  
pp. 4288-4296 ◽  
Author(s):  
Magali Pederzoli-Ribeil ◽  
Francesco Maione ◽  
Dianne Cooper ◽  
Adam Al-Kashi ◽  
Jesmond Dalli ◽  
...  

Abstract Human polymorphonuclear leukocytes adhesion to endothelial cells during the early stage of inflammation leads to cell surface externalization of Annexin A1 (AnxA1), an effector of endogenous anti-inflammation. The antiadhesive properties of AnxA1 become operative to finely tune polymorphonuclear leukocytes transmigration to the site of inflammation. Membrane bound proteinase 3 (PR3) plays a key role in this microenvironment by cleaving the N terminus bioactive domain of AnxA1. In the present study, we generated a PR3-resistant human recombinant AnxA1—named superAnxA1 (SAnxA1)—and tested its in vitro and in vivo properties in comparison to the parental protein. SAnxA1 bound and activated formyl peptide receptor 2 in a similar way as the parental protein, while showing a resistance to cleavage by recombinant PR3. SAnxA1 retained anti-inflammatory activities in the murine inflamed microcirculation (leukocyte adhesion being the readout) and in skin trafficking model. When longer-lasting models of inflammation were applied, SAnxA1 displayed stronger anti-inflammatory effect over time compared with the parental protein. Together these results indicate that AnxA1 cleavage is an important process during neutrophilic inflammation and that controlling the balance between AnxA1/PR3 activities might represent a promising avenue for the discovery of novel therapeutic approaches.


2007 ◽  
Vol 14 (6) ◽  
pp. 678-684
Author(s):  
Eiji Ohara ◽  
Yoshitaka Kumon ◽  
Toshihiro Kobayashi ◽  
Hiroaki Takeuchi ◽  
Tetsuro Sugiura

ABSTRACT N-Formyl peptide receptor-like 1 (fPRL1) is a member of the chemoattractant subfamily of G protein-coupled receptors and plays a key role in inflammation via chemotaxis and the regulation of mediator release from leukocytes. Activated fPRL1 has recently been shown to induce a complicated pattern of cellular signaling in vitro, but the details of the regulation and alteration of leukocyte cellular fPRL1 during inflammation in vivo remain unclear. To clarify the alteration of neutrophil fPRL1 during inflammation in vivo, the immunohistochemical staining of neutrophil fPRL1 in samples from patients with purulent dermatitis was performed. The in vitro morphological alteration of neutrophil fPRL1 on cellular membranes by stimulation with N-formylmethionyl-leucyl-phenylalanine (fMLP) was also examined. Both the cytoplasm and the cellular membranes of blood neutrophils stained strongly for fPRL1. On the other hand, the cellular membranes of neutrophils in dermatitis tissue stained strongly for fPRL1 but the cytoplasm stained weakly. The enhancement of neutrophil fPRL1 on cellular membranes by stimulation with fMLP indicates the exocytosis of neutrophil fPRL1-containing granules. In conclusion, we for the first time confirmed the alteration of neutrophil fPRL1 in clinical cases of purulent dermatitis. Cytoplasm that was weakly stained and cellular membranes that were well stained for fPRL1 were considered to be distinctive features of activated neutrophils in purulent dermatitis tissue.


Cells ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 228
Author(s):  
Izabella Lice ◽  
José Marcos Sanches ◽  
Rebeca D. Correia-Silva ◽  
Mab P. Corrêa ◽  
Marcelo Y. Icimoto ◽  
...  

Formyl peptide receptors (Fprs) are a G-protein-coupled receptor family mainly expressed on leukocytes. The activation of Fpr1 and Fpr2 triggers a cascade of signaling events, leading to leukocyte migration, cytokine release, and increased phagocytosis. In this study, we evaluate the effects of the Fpr1 and Fpr2 agonists Ac9-12 and WKYMV, respectively, in carrageenan-induced acute peritonitis and LPS-stimulated macrophages. Peritonitis was induced in male C57BL/6 mice through the intraperitoneal injection of 1 mL of 3% carrageenan solution or saline (control). Pre-treatments with Ac9-12 and WKYMV reduced leukocyte influx to the peritoneal cavity, particularly neutrophils and monocytes, and the release of IL-1β. The addition of the Fpr2 antagonist WRW4 reversed only the anti-inflammatory actions of WKYMV. In vitro, the administration of Boc2 and WRW4 reversed the effects of Ac9-12 and WKYMV, respectively, in the production of IL-6 by LPS-stimulated macrophages. These biological effects of peptides were differently regulated by ERK and p38 signaling pathways. Lipidomic analysis evidenced that Ac9-12 and WKYMV altered the intracellular lipid profile of LPS-stimulated macrophages, revealing an increased concentration of several glycerophospholipids, suggesting regulation of inflammatory pathways triggered by LPS. Overall, our data indicate the therapeutic potential of Ac9-12 and WKYMV via Fpr1 or Fpr2-activation in the inflammatory response and macrophage activation.


2007 ◽  
Vol 97 (2) ◽  
pp. 281-288 ◽  
Author(s):  
Jennifer Gilman ◽  
Kevin D. Cashman

Marine oil-derived n-3 fatty acids have been shown to stimulate intestinal Ca absorption in animal studies, but the effects of such fatty acids on Ca absorption in human subjects are relatively unknown. In particular, n-3 fatty acids may be of therapeutic value for some Crohn's disease patients who experience Ca malabsorption. Therefore, the aim of the present study was to investigate the effect of 20 : 5n-3 and 22 : 6n-3 on transepithelial Ca transport across monolayers of healthy Caco-2 cells as well as of TNF-α-treated Caco-2 cells (an in vitro model of Crohn's disease). Caco-2 cells were seeded onto permeable filter supports and allowed to differentiate into monolayers, which were treated with 80 μm-20 : 5n-3, 80 μm-22 : 6n-3, or 40 μm-20 : 5n-3+40 μm-22 : 6n-3 for 6 or 8 d, with or without co-treatment with TNF-α (10 ng/ml) (n 11–15 monolayers per treatment). On day 16, transepithelial and transcellular transport of 45Ca and fluorescein transport (a marker of paracellular diffusion) were measured. Treatment of healthy and inflamed Caco-2 cells with 20 : 5n-3, 22 : 6n-3 and both fatty acids combined for 8 d significantly (P < 0·005–0·01) increased total transepithelial Ca transport compared with that in control, effects which were mediated by an enhanced rate of transcellular Ca transport. The effects of n-3 fatty acids on Ca absorption after 6 d were less clear-cut. In conclusion, the present in vitro findings highlight the need to investigate the effect of marine oil-based n-3 fatty acids on Ca absorption in vivo in studies of healthy human subjects as well as of Crohn's disease patients.


2015 ◽  
Vol 4 ◽  
Author(s):  
P. Ramnani ◽  
A. Costabile ◽  
A. G. R. Bustillo ◽  
G. R. Gibson

AbstractThis placebo-controlled, randomised, double-blind, cross-over human feeding study aimed to determine the prebiotic effect of agave fructans. A total of thirty-eight volunteers completed this trial. The treatment consisted of 3 weeks' supplementation with 5 g/d of prebiotic agave fructan (Predilife) or equivalent placebo (maltodextrin), followed by a 2-week washout period following which subjects were crossed over to alternate the treatment arm for 3 weeks followed by a 2-week washout. Faecal samples were collected at baseline, on the last day of treatment (days 22 and 58) and washout (days 36 and 72), respectively. Changes in faecal bacterial populations, SCFA and secretory IgA were assessed using fluorescentin situhybridisation, GC and ELISA, respectively. Bowel movements, stool consistencies, abdominal comfort and mood changes were evaluated by a recorded daily questionnaire. In parallel, the effect of agave fructans on different regions of the colon using a three-stage continuous culture simulator was studied. Predilife significantly increased faecal bifidobacteria (log109·6 (sd0·4)) and lactobacilli (log107·7 (sd0·8)) compared with placebo (log109·2 (sd0·4);P = 0·00) (log107·4 (sd0·7);P= 0·000), respectively. No change was observed for other bacterial groups tested, SCFA, secretory IgA, and PGE2concentrations between the treatment and placebo. Denaturing gradient gel electrophoresis analysis indicated that bacterial communities were randomly dispersed and no significant differences were observed between Predilife and placebo treatments. Thein vitromodels showed similar increases in bifidobacterial and lactobacilli populations to that observed with thein vivotrial. To conclude, agave fructans are well tolerated in healthy human subjects and increased bifidobacteria and lactobacilli numbersin vitroandin vivobut did not influence other products of fermentation.


Biomedicines ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 219
Author(s):  
Vickie Beaupré ◽  
Nathalie Boucher ◽  
Isabel Desgagné-Penix

The anti-inflammatory and antioxidant role of Thykamine, a botanical extract of thylakoides obtained from spinach leaves, has been investigated in animal and cellular models. The oxidative properties have been proven by inhibiting NO production (>98%) in J774A.1 cells and by protecting a linoelic acid emulsion subjected to lipid peroxidation caused by AAPH. Thykamine injected intraperitoneally to rats reduced the inflammatory process of (TNBS)-induced colitis and carrageenan-induced paw edema. As neutrophils are the first cells to migrate to inflammatory sites, the influence of Thykamine on the primary neutrophil functions were studied. Thykamine dose-dependent reduced neutrophil chemiotaxis, phagocytosis, and degranulation. No change in the release of LDH by neutrophils on Thykamine was recorded. Thykamine inhibited by 85% the neutrophil production of O2−. A superoxide recovery activity was observed on a zymography demonstrating a SOD-like enzyme on Thykamine extracts. Spontaneous fluorescence provided by carotenoid and chlorophyll pigments (488/675 nm) detected Thykamine on the surface, in the cytoplasm (mainly central where Golgi are present) and weakly in the nucleus of neutrophils. The results argue that SOD and pigments found in Thykamine are part of its antioxidant and anti-inflammatory properties shown in in vivo and in vitro models of inflammation.


2018 ◽  
Vol 28 (6) ◽  
pp. 723-738 ◽  
Author(s):  
Weijian Fan ◽  
Xiang Li ◽  
Dongping Zhang ◽  
Haiying Li ◽  
Haitao Shen ◽  
...  

Although microRNA-144-3p (miRNA-144-3p) has been shown to suppress tumor proliferation and invasion, its function in intracerebral hemorrhage (ICH)-induced secondary brain injury (SBI) remains unclear. Thus, this study was designed to investigate the role of miRNA-144-3p in ICH. To accomplish this, we used adult male Sprague-Dawley rats to establish an in vivo ICH model by injecting autologous blood, while cultured primary rat cortical neurons were exposed to oxyhemoglobin (OxyHb) to mimic ICH in vitro. To examine the role of miRNA-144-3p in ICH-induced SBI, we used an miRNA-144-3p mimic and inhibitor both in vivo and in vitro. Following ICH induction, we found miRNA-144-3p expression to increase. Additionally, we predicted the formyl peptide receptor 2 (FPR2) to be a potential miRNA-144-3p target, which we validated experimentally, with FPR2 expression downregulated when miRNA-144-3p was upregulated. Furthermore, elevated miRNA-144-3p levels aggravated brain edema and neurobehavioral disorders and induced neuronal apoptosis via the downregulation of FPR2 both in vivo and in vitro. We suspected that these beneficial effects provided by FPR2 were associated with the PI3K/AKT pathway. We validated this finding by overexpressing FPR2 while inhibiting PI3K/AKT in vitro and in vivo. In conclusion, miRNA-144-3p aggravated ICH-induced SBI by targeting and downregulating FPR2, thereby contributing to neurological dysfunction and neural apoptosis via PI3K/AKT pathway activation. These findings suggest that inhibiting miRNA-144-3p may offer an effective approach to attenuating brain damage incurred after ICH and a potential therapy to improve ICH-induced SBI.


2020 ◽  
pp. IAI.00680-20
Author(s):  
Chengpei Ni ◽  
Song Gao ◽  
Yuling Zheng ◽  
Peng Liu ◽  
Yajie Zhai ◽  
...  

Streptococcus suis (S. suis) serotype 2 is a crucial pathogenic cause of bacterial meningitis, a life-threatening disease with neurological sequelae and high rates of mortality. Inflammation triggered by S. suis infection must be precisely regulated to prevent further tissue damage. As a glucocorticoid anti-inflammatory mediator, Annexin A1 (AnxA1) mainly acts through formyl peptide receptor 2 (Fpr2) to alleviate inflammation in the peripheral system. In this research, we evaluated the roles of AnxA1 and Fpr2 in a mouse model of S. suis meningitis created via intracisternal infection in Fpr2-deficient (Fpr2−/−) and wild-type (WT) mice. We revealed that Fpr2−/− mice were highly susceptible to S. suis meningitis, displaying increased inflammatory cytokine levels, bacterial dissemination, and neutrophil migration compared with the findings in WT mice. Additionally, AnxA1 exerted anti-inflammatory effects through Fpr2, such as attenuation of leukocyte infiltration, inflammatory mediator production, and astrocyte or microglial activation in the brain. Importantly, we found that the anti-migratory function of AnxA1 decreases neutrophil adherence to the endothelium through Fpr2. Finally, an in vitro study revealed that AnxA1 potentially suppresses IL-6 expression through the Fpr2/p38/COX-2 pathway. These data demonstrated that Fpr2 is an anti-inflammatory receptor that regulates neutrophil migration in mice with S. suis meningitis and identified AnxA1 as a potential therapeutic option.


2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Jennie M. Gane ◽  
Robert A. Stockley ◽  
Elizabeth Sapey

Selective TNFR1 blockade in inflammatory diseases is emerging as a clinical strategy. We studied the roles of the two TNF-αreceptors, TNFR1 and TNFR2, in human monocytes, the principal producer of TNF-αand central to many TNF-αdriven diseases. We hypothesised that TNF-αhas pro- and anti-inflammatory effects on monocytes, occurring differentially via TNFR1 and TNFR2. Monocytes were isolated from healthy human subjects and exposed to LPS, plus/minus the addition of blocking antibodies to TNF-αor its receptors. Pro- and anti-inflammatory cytokine production was quantified using real-time PCR and ELISAs. Cell surface expression of TNFR1/2 was measured by flow cytometry. We demonstrated that monocytes vary in the expression patterns of TNFR1 and TNFR2. Autocrine binding of TNF-αled to sustained upregulation of proinflammatory cytokines via TNFR1. In contrast, autocrine binding via TNFR2 upregulated theanti-inflammatory cytokine, IL-10, without proinflammatory effect. TNFR2 was responsible for binding soluble TNF-αsecreted by monocytes, clearing the cytokine from the pericellular environment. TNFR1 blockade did not change the cell surface expression of TNFR2, leaving this receptor free to upregulate IL-10. These novel results support the concept of selective TNFR1 blockadein vivoin order that positive anti-inflammatory effects of TNF-αcan be retained via TNFR2 ligation.


Sign in / Sign up

Export Citation Format

Share Document