8 research outputs found
Identification of 2,4-Dinitro-Biphenyl-Based Compounds as MAPEG Inhibitors
We identified 2,4-dinitro-biphenyl-based compounds as new inhibitors of leukotriene C-4 synthase (LTC4S) and 5-lipoxygenase-activating protein (FLAP), both members of the "Membrane Associated Proteins in Eicosanoid and Glutathione metabolism" (MAPEG) family involved in the biosynthesis of pro-inflammatory eicosanoids. By molecular docking we evaluated the putative binding against the targets of interest, and by applying cell-free and cell-based assays we assessed the inhibition of LTC4S and FLAP by the small molecules at low micromolar concentrations. The present results integrate the previously observed inhibitory profile of the tested compounds against another MAPEG member, i. e., microsomal prostaglandin E-2 synthase (mPGES)-1, suggesting that the 2,4-dinitro-biphenyl scaffold is a suitable molecular platform for a multitargeting approach to modulate pro-inflammatory mediators in inflammation and cancer treatment
BRP-187: A potent inhibitor of leukotriene biosynthesis that acts through impeding the dynamic 5-lipoxygenase/5-lipoxygenase-activating protein (FLAP) complex assembly
The pro-inflammatory leukotrienes (LTs) are formed from arachidonic acid (AA) in activated leukocytes, where 5-lipoxygenase (5-LO) translocates to the nuclear envelope to assemble a functional complex with the integral nuclear membrane protein 5-LO-activating protein (FLAP). FLAP, a MAPEG family member, facilitates AA transfer to 5-LO for efficient conversion, and LT biosynthesis critically depends on FLAP. Here we show that the novel LT biosynthesis inhibitor BRP-187 prevents the 5-LO/FLAP interaction at the nuclear envelope of human leukocytes without blocking 5-LO nuclear redistribution. BRP-187 inhibited 5-LO product formation in human monocytes and polymorphonuclear leukocytes stimulated by lipopolysaccharide plus N-formyl-methionyl-leucyl-phenylalanine (IC50=7-10nM), and upon activation by ionophore A23187 (IC50=10-60nM). Excess of exogenous AA markedly impaired the potency of BRP-187. Direct 5-LO inhibition in cell-free assays was evident only at >35-fold higher concentrations, which was reversible and not improved under reducing conditions. BRP-187 prevented A23187-induced 5-LO/FLAP complex assembly in leukocytes but failed to block 5-LO nuclear translocation, features that were shared with the FLAP inhibitor MK886. Whereas AA release, cyclooxygenases and related LOs were unaffected, BRP-187 also potently inhibited microsomal prostaglandin E2 synthase-1 (IC50=0.2μM), another MAPEG member. In vivo, BRP-187 (10mg/kg) exhibited significant effectiveness in zymosan-induced murine peritonitis, suppressing LT levels in peritoneal exudates as well as vascular permeability and neutrophil infiltration. Together, BRP-187 potently inhibits LT biosynthesis in vitro and in vivo, which seemingly is caused by preventing the 5-LO/FLAP complex assembly and warrants further preclinical evaluation
12-Oxo-10-glutathionyl-5,8,14-eicosatrienoic acid (TOG10), a novel glutathione-containing eicosanoid generated via the 12-lipoxygenase pathway in human platelets
Pharmacological profile and efficiency in vivo of diflapolin, the first dual inhibitor of 5-lipoxygenase-activating protein and soluble epoxide hydrolase
Abstract Arachidonic acid (AA) is metabolized to diverse bioactive lipid mediators. Whereas the 5-lipoxygenase-activating protein (FLAP) facilitates AA conversion by 5-lipoxygenase (5-LOX) to pro-inflammatory leukotrienes (LTs), the soluble epoxide hydrolase (sEH) degrades anti-inflammatory epoxyeicosatrienoic acids (EETs). Accordingly, dual FLAP/sEH inhibition might be advantageous drugs for intervention of inflammation. We present the in vivo pharmacological profile and efficiency of N-[4-(benzothiazol-2-ylmethoxy)-2-methylphenyl]-N′-(3,4-dichlorophenyl)urea (diflapolin) that dually targets FLAP and sEH. Diflapolin inhibited 5-LOX product formation in intact human monocytes and neutrophils with IC50 = 30 and 170 nM, respectively, and suppressed the activity of isolated sEH (IC50 = 20 nM). Characteristic for FLAP inhibitors, diflapolin (I) failed to inhibit isolated 5-LOX, (II) blocked 5-LOX product formation in HEK cells only when 5-LOX/FLAP was co-expressed, (III) lost potency in intact cells when exogenous AA was supplied, and (IV) prevented 5-LOX/FLAP complex assembly in leukocytes. Diflapolin showed target specificity, as other enzymes related to AA metabolism (i.e., COX1/2, 12/15-LOX, LTA4H, LTC4S, mPGES1, and cPLA2) were not inhibited. In the zymosan-induced mouse peritonitis model, diflapolin impaired vascular permeability, inhibited cysteinyl-LTs and LTB4 formation, and suppressed neutrophil infiltration. Diflapolin is a highly active dual FLAP/sEH inhibitor in vitro and in vivo with target specificity to treat inflammation-related diseases
Discovery of a benzenesulfonamide-based dual inhibitor of microsomal prostaglandin E2 synthase-1 and 5-lipoxygenase that favorably modulates lipid mediator biosynthesis in inflammation
Leukotrienes (LTs) and prostaglandin (PG)E2, produced by 5-lipoxygenase (5-LO) and microsomal prostaglandin
E2 synthase-1 (mPGES-1), respectively, are key players in inflammation, and pharmacological
suppression of these lipid mediators (LM) represents a strategy to intervene with inflammatory disorders.
Previous studies revealed that the benzenesulfonamide scaffold displays efficient 5-LO-inhibitory
properties. Here, we structurally optimized benzenesulfonamides which led to an N-phenylbenzenesulfonamide
derivative (compound 47) with potent inhibitory activities (IC50 ¼ 2.3 and 0.4 mM
for isolated 5-LO and 5-LO in intact cells, respectively). Compound 47 prevented the interaction of 5-LO
with its activating protein (FLAP) at the nuclear envelope in transfected HEK293 cells as shown by in situ
proximity ligation assay. Comprehensive assessment of the LM profile produced by human macrophages
revealed the ability of 47 to selectively down-regulate pro-inflammatory LMs (i.e. LTs and PGE2) in M1
but to enhance the formation of pro-resolving LMs (i.e. resolvins and maresins) in M2 macrophages.
Moreover, 47 strongly inhibited LT formation and cell infiltration in two in vivo models of acute
inflammation (i.e., peritonitis and air pouch sterile inflammation in mice). Together, 47 represents a
novel LT biosynthesis inhibitor with an attractive pharmacological profile as anti-inflammatory drug that
also promotes the biosynthesis of pro-resolving LM
The 5-lipoxygenase inhibitor RF-22c potently suppresses leukotriene biosynthesis in cellulo and blocks bronchoconstriction and inflammation in vivo
5-Lipoxygenase (5-LO) catalyzes the first two steps in leukotriene (LT) biosynthesis. Because LTs play pivotal roles in allergy and inflammation, 5-LO represents a valuable target for anti-inflammatory drugs. Here, we investigated the molecular mechanism, the pharmacological profile, and the in vivo effectiveness of the novel 1,2-benzoquinone-featured 5-LO inhibitor RF-22c. Compound RF-22c potently inhibited 5-LO product synthesis in neutrophils and monocytes (IC50⩾22nM) and in cell-free assays (IC50⩾140nM) without affecting 12/15-LOs, cyclooxygenase (COX)-1/2, or arachidonic acid release, in a specific and reversible manner, supported by molecular docking data. Antioxidant or iron-chelating properties were not evident for RF-22c and 5-LO-regulatory cofactors like Ca(2+) mobilization, ERK-1/2 activation, and 5-LO nuclear membrane translocation and interaction with 5-LO-activating protein (FLAP) were unaffected. RF-22c (0.1mg/kg; i.p.) impaired (I) bronchoconstriction in ovalbumin-sensitized mice challenged with acetylcholine, (II) exudate formation in carrageenan-induced paw edema, and (III) zymosan-induced leukocyte infiltration in air pouches. Taken together, RF-22c is a highly selective and potent 5-LO inhibitor in intact human leukocytes with pronounced effectiveness in different models of inflammation that warrants further preclinical analysis of this agent as anti-inflammatory drug
Aminothiazole-Featured Pirinixic Acid Derivatives As Dual 5‑Lipoxygenase and Microsomal Prostaglandin E<sub>2</sub> Synthase‑1 Inhibitors with Improved Potency and Efficiency in Vivo
Dual
inhibition of microsomal prostaglandin E<sub>2</sub> synthase-1
(mPGES-1) and 5-lipoxygenase (5-LO) is currently pursued as potential
pharmacological strategy for treatment of inflammation and cancer.
Here we present a series of 26 novel 2-aminothiazole-featured pirinixic
acid derivatives as dual 5-LO/mPGES-1 inhibitors with improved potency
(exemplified by compound <b>16</b> (2-[(4-chloro-6-{[4-(naphthalen-2-yl)-1,3-thiazol-2-yl]Âamino}Âpyrimidin-2-yl)Âsulfanyl]Âoctanoic
acid) with IC<sub>50</sub> = 0.3 and 0.4 μM, respectively) and
bioactivity in vivo. Computational analysis presumes binding sites
of <b>16</b> at the tip of the 5-LO catalytic domain and within
a subpocket of the mPGES-1 active site. Compound <b>16</b> (10
μM) hardly suppressed cyclooxygenase (COX)-1/2 activities, failed
to inhibit 12/15-LOs, and is devoid of radical scavenger properties.
Finally, compound <b>16</b> reduced vascular permeability and
inflammatory cell infiltration in a zymosan-induced mouse peritonitis
model accompanied by impaired levels of cysteinyl-leukotrienes and
prostaglandin E<sub>2</sub>. Together, 2-aminothiazole-featured pirinixic
acids represent potent dual 5-LO/mPGES-1 inhibitors with an attractive
pharmacological profile as anti-inflammatory drugs