Amlexanox

TBK1/IKKε inhibitor

TBK1/IKKε signaling inhibition by Amlexanox

Amlexanox is a specific inhibitor of the noncanonical  IkB kinases TANK-binding kinase 1 (TBK1) and IkappaB kinase-epsilon (IKKε) [1]. TBK1 and IKKε play a central role in the innate immune response. Notably, these noncanonical IkappaB kinase homologs are essential components of the interferon regulatory factor (IRF) signaling pathway. 

 More details

Mode of action:

Amlexanox inhibits TBK1 and IKK-ε by competing for ATP-binding to the enzyme. At the concentrations that block TBK1 and IKKε, Amlexanox has no effect on the canonical IkB kinases IKKα and IKKβ, or a large panel of other kinases.

IKKε and TBK1 are essential players in the coordination of interferon regulatory factor 3 (IRF3)- and NF‑κB-mediated inflammatory signaling pathways. Indeed, elevated IKKε and TBK1 activity has been associated with several inflammatory diseases [2,3]. 

Of note, Amlexanox has been approved for the treatment of a variety of conditions, including asthma and aphthous ulcers, due to its anti-inflammatory and anti‑allergic properties. It is being investigated as a novel therapeutic for type II diabetes and obesity [1], as increased IKKε and TBK1 activity has been linked to low-grade chronic inflammation associated with insulin resistance and metabolic disorders [4].

Key features:

• A potent and specific inhibitor of TBK1 and IKK-ε
• InvitroFit™ grade: each lot is highly pure (≥97%) and functionally tested

References

1. Reilly SM. et al., 2013. An inhibitor of the protein kinases TBK1 and IKK-e improves obesity-related metabolic dysfunctions in mice. Nat Med. 19(3):313-21.
2. Yu J. et al., 2015. Regulation of T-cell activation and migration by the kinase TBK1 during neuroinflammation. Nat Commun. 6:6074.
3. Niederberger E. et al., 2013. The non-canonical IkB kinases IKKe and TBK1 as potential targets for the development of novel therapeutic drugs. Curr Mol Med. 13(7):1089-97.
4. Chiang SH. et al., 2009. The protein kinase IKKepsilon regulates energy balance in obese mice. Cell. 138(5):961-75.

Figures

Amlexanox is a potent inhibitor of TBK1/IKKε signaling pathways.
B16-Blue™ ISG cells were incubated overnight at 37°C in the presence of increasing concentrations of Amlexanox together with 5 μg/ml of poly(dA:dT) complexed with the transfection reagent LyoVec™. The next day, the inhibitory activity of Amlexanox was determined by measuring the reduction of SEAP production in the supernatant using the QUANTI-Blue™ Solution detection reagent. Data are shown as percentage (%) inhibition.

Specifications

CAS number: 68302-57-8

Working concentration: 1-300 μg/ml for cell culture assays

Solubility: 10 mg/ml (33.5 mM) in DMSO

Formula: C₁₆H₁₄N₂O₄

Molecular weight: 298.3 g/mol

Quality control:

• Purity ≥ 97% (UHPLC)
• The inhibitory activity has been validated using cellular assays.
• The absence of bacterial contamination (e.g. lipoproteins and endotoxins) has been confirmed using HEK-Blue™ TLR2 and HEK-Blue™ TLR4 cells.

Contents

Amlexanox is provided lyophilized.

• 50 mg Amlexanox

Amlexanox is shipped at room temperature.

Upon receipt, store at -20°C.

 The resuspended product is stable for 6 months at -20°C when properly stored. Avoid repeated freeze-thaw cycles.

Details

TBK1 /IKKε

TANK-binding kinase 1 (TBK1; also known as NF-κB activating kinase/NAK and T2K) is a multifunctional serine/threonine-protein kinase that belongs to the non-canonical IκB kinase family, together with its close homolog IkB kinase ε (IKKε, also known as IKKi). TBK1 plays an important role in the regulation of many cellular processes, including innate immunity, inflammatory cytokine production, autophagy, mitochondrial metabolism, and cell survival/proliferation [1].
In innate immune signaling, TBK1 acts as an integrator of receptor-mediated pathogen detection signals and as an interferon (IFN) response modulator [2, 3]. Viral, bacterial, or tumor DNA activate STING (stimulator of interferon genes protein), which triggers TBK1 signaling and results in the activation of the transcription factors IRF3 (IFN regulatory factor 3)and IRF7 to induce the expression of type-I IFNs. Additionally, TBK1 plays a role in other signaling pathways triggered by other innate adaptors, such as MAVS (mitochondrial antiviral signaling protein) and TRIF (TIR-domain-containing adapter-inducing interferon-β).

References:

1. Herhaus L., 2021. TBK1 (TANK-binding kinase 1)-mediated regulation of autophagy in health and disease. Matrix Biol. 100-101:84-98.
2. Durand J.K. et al., 2018. Roles for the IKK-related kinases TBK1 and IKKε in cancer. Cells. 7(9):139.
3. Runde AP. et al., 2022. The role of TBK1 in cancer pathogenesis and anticancer immunity J Exp Clin Cancer Res . 41(1):135.

Chemical structure of Amlexanox: