6-bromoindirubin-3--oxime and Inflammation

The most common inflammatory disease of the airways is asthma among children affecting around 235 million people worldwide. 5-Lipoxygenase (5-LOX) is a crucial enzyme which helps in the conversion of arachidonic acid (AA) to leukotrienes (LTs), the lipid mediators. It is associated with several inflammation related disorders such as asthma, allergy, and atherosclerosis. Therefore, it is considered as a promising target against inflammation and asthma. Currently, the only drug against 5-LOX which is available is Zileuton, while a few inhibitors are in clinical trial stages such as Atreleuton and Setileuton. So, there is a dire requirement in the area of progress of novel 5-LOX inhibitors which necessitates an understanding of their structure activity relationship and mode of action. In this review, novel 5-LOX inhibitors reported so far, their structural design, SAR and developmental strategies along with clinical updates are discussed over the last two decades.

Topics: Animals; Arachidonate 5-Lipoxygenase; Dose-Response Relationship, Drug; Drug Design; Humans; Inflammation; Leukotrienes; Lipoxygenase Inhibitors; Molecular Structure; Structure-Activity Relationship

The transcription factor β-catenin is able to induce tolerogenic/anti-inflammatory features in different types of dendritic cells (DCs). Monocyte-derived dendritic cells (moDCs) have been widely used in dendritic cell-based cancer therapy, but so far with limited clinical efficacy. We wanted to investigate the hypothesis that aberrant differentiation or induction of dual pro- and anti-inflammatory features may be β-catenin dependent in moDCs. β-catenin was detectable in both immature and lipopolysaccharide (LPS)-stimulated DCs. The β-catenin inhibitor ICG-001 dose-dependently increased the pro-inflammatory signature cytokine IL-12p70 and decreased the anti-inflammatory signature molecule IL-10. The β-catenin activator 6-bromoindirubin-3'-oxime (6-BIO) dose-dependently increased total and nuclear β-catenin, and this was associated with decreased IL-12p70, increased IL-10, and reduced surface expression of activation markers, such as CD80 and CD86, and increased expression of inhibitory markers, such as PD-L1. 6-BIO and ICG-001 competed dose-dependently regarding these features. Genome-wide mRNA expression analyses further underscored the dual development of pro- and anti-inflammatory features of LPS-matured moDCs and suggest a role for β-catenin inhibition in production of more potent therapeutic moDCs.

Topics: B7-H1 Antigen; beta Catenin; Bridged Bicyclo Compounds, Heterocyclic; Cell Differentiation; Cells, Cultured; Dendritic Cells; Gene Expression Regulation; Humans; Immune Tolerance; Indoles; Inflammation; Interleukin-10; Interleukin-12; Lipopolysaccharides; Monocytes; Oximes; Pyrimidinones

We investigated the efficacy of the traditional herbal extract 6-bromoindirubin-3'-oxime (BIO) against lipopolysaccharide (LPS)-induced mastitis in mice and inflammatory signaling in mouse mammary epithelial cells (MMECs). In vivo, breast inflammation scores and enzyme-linked immunosorbent assay (ELISA) detection of pro-inflammatory factor expression were used to assess the effect of BIO against mastitis. In vitro, the effects of BIO on LPS-induced changes in the expression levels of pro-inflammatory factors, anti-inflammatory cytokines, and signaling factors of the toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) and TLR4/mitogen-activated protein kinase (MAPK) pathways were examined by qRT-PCR and ELISA. In LPS-injected mice, BIO pretreatment downregulated the expression of the pro-inflammatory factors interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and myeloperoxidase (MPO) in mammary glands and reduced inflammatory lesions in breast tissue. In MMECs, BIO pretreatment downregulated the LPS-induced expression of IL-1β, IL-6, and TNF-α. Further, BIO inhibited both the expression and phosphorylation of TLR4/NF-κB and TLR4/MAPK signaling factors. Thus, BIO downregulates IL-6, IL-1β, TNF-α, and MPO expression, upregulates IL-10 expression, and suppresses LPS-induced inflammation by inhibiting the TLR4/NF-κB and TLR4/MAPK pathways. BIO may be a potential treatment agent for mastitis and other inflammatory diseases.

Topics: Animals; Female; Indoles; Inflammation; Lipopolysaccharides; Mammary Glands, Animal; MAP Kinase Signaling System; Mastitis; Mice; NF-kappa B; Oximes; Signal Transduction; Toll-Like Receptor 4

Stroke induces blood-brain barrier (BBB) breakdown, which promotes complications like oedema and hemorrhagic transformation. Administration of recombinant tissue plasminogen activator (rtPA) within a therapeutic time window of 4.5 h after stroke onset constitutes the only existing treatment. Beyond this time window, rtPA worsens BBB breakdown. Canonical Wnt pathway induces BBB formation and maturation during ontogeny. We hypothesized that the pathway is required to maintain BBB functions after stroke; thus, its activation might improve rtPA therapy. Therefore, we first assessed pathway activity in the brain of mice subjected to transient middle cerebral artery occlusion (MCAo). Next, we evaluated the effect of pathway deactivation early after stroke onset on BBB functions. Finally, we assessed the impact of pathway activation on BBB breakdown associated to delayed administration of rtPA. Our results show that pathway activity is induced predominately in endothelial cells early after ischemic stroke. Early deactivation of the pathway using a potent inhibitor, XAV939, aggravates BBB breakdown and increases hemorrhagic transformation incidence. On the other hand, pathway activation using a potent activator, 6-bromoindirubin-3'-oxime (6-BIO), reduces the incidence of hemorrhagic transformation associated to delayed rtPA administration by attenuating BBB breakdown via promotion of tight junction formation and repressing endothelial basal permeability independently of rtPA proteolytic activity. BBB preservation upon pathway activation limited the deleterious effects of delayed rtPA administration. Our study demonstrates that activation of the canonical Wnt pathway constitutes a clinically relevant strategy to extend the therapeutic time window of rtPA by attenuating BBB breakdown via regulation of BBB-specific mechanisms.

Topics: Animals; Blood-Brain Barrier; Brain Ischemia; Cerebral Hemorrhage; Endothelial Cells; Glucose; Indoles; Inflammation; Mice, Inbred C57BL; Microvessels; Neovascularization, Physiologic; Neurons; Oximes; Oxygen; Permeability; Stroke; Tight Junctions; Tissue Plasminogen Activator; Wnt Signaling Pathway

This protocol describes microsphere-based protease assays for use in flow cytometry and high-throughput screening. This platform measures a loss of fluorescence from the surface of a microsphere due to the cleavage of an attached fluorescent protease substrate by a suitable protease enzyme. The assay format can be adapted to any site or protein-specific protease of interest and results can be measured in both real time and as endpoint fluorescence assays on a flow cytometer. Endpoint assays are easily adapted to microplate format for flow cytometry high-throughput analysis and inhibitor screening.

Topics: Animals; Biotinylation; Flow Cytometry; Fluorescence Resonance Energy Transfer; Green Fluorescent Proteins; High-Throughput Screening Assays; Humans; Inflammation; Kinetics; Microspheres; Peptide Hydrolases; Peptides; Reproducibility of Results; Temperature