TDI-6570

Specific inhibitor of mouse cGAS

Inhibition of cGAS signaling by TDI-6570

TDI-6570 is described as a small molecule inhibitor of the murine cytosolic double-stranded (ds)DNA sensor cyclic GMP-AMP synthase (cGAS) [1]. cGAS is the primary sensor of cytosolic dsDNA, a danger signal indicating possible disturbances in homeostasis caused by infection, sterile tissue damage, or cancer [1-3]. 

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Mode of action

In a healthy individual, cGAS senses the abnormal presence of cytosolic DNA in the context of infection. In diseases, cGAS hyperactivation promotes deleterious type I IFN responses and therefore drives neurodegenerative diseases [2]. TDI-6570 is described as one of the most potent inhibitors for mouse cGAS [3]. It possesses high gastrointestinal absorption and good brain permeability [1-2]. TDI-6570 has been used to determine the effects of cGAS inhibition on the cGAS-STING pathway in a mouse model of tauopathy (Alzheimer's disease (AD)) [1]. Even high concentrations of TDI-6570 show no substantial toxicity [1]. TDI-6570 can be formulated into chow diet and is orally administrable [1-2]. Inhibition of cGAS using TDI-6570 represents a promising therapeutic strategy to treat multiple neurodegenerative diseases, including AD,  Huntington's, or Parkinson's disease [3]. 

InvivoGen's TDI-6570 efficiently inhibits mouse cGAS, but not human cGAS, as assessed using InvivoGen's reporter cell lines J774-Dual™ and THP1-Dual™, respectively (see figures).

InvivoGen's TDI-6570 is for research purposes only; not for human or veterinary use.

Key features of TDI-6570

• Potent and specific inhibitor of mouse cGAS
• No substantial toxicity in vivo [1]
• Orally administrable in mice [1] 
• InvitroFit™ grade: each lot is highly pure (≥95%) and functionally tested.

Read our review on cGAS.

References:

1. Lo I, et al. 2023. Tau activation of microglial cGAS-IFN reduces MEF2C-mediated cognitive resilience. Nat Neurosci. 26(5):737-750.
2. Lama L, et al. 2019. Development of human cGAS-specific small-molecule inhibitors for repression of dsDNA-triggered interferon expression. Nat Commun.10(1):2261.
3. Huang Y, et al. 2023. . Mechanism and therapeutic potential of targeting cGAS-STING signaling in neurological disorders. Mol Neurodegener.18(1):79.

Figures

Dose-dependent inhibition of mouse cGAS​. J774-Dual™ cells were cultured in the presence of increasing concentrations of TDI-6570. After 3 hours of incubation, the following ligands were added: 1 µg/ml G3-YSD or Poly(dA:dT) (cGAS agonists), complexed with LyoVec™ (LV) or 10 µg/ml 2’3’-cGAMP (STING agonist). After overnight incubation, the neutralizing activity of TDI-6570 was determined by measuring the reduction of Lucia luciferase production in the supernatant using the QUANTI-Luc™ 4 detection reagent. Data are shown as a percentage (%) of inhibition.

Inhibitory effect of TDI-6570 on human cGAS. Human monocytic THP1-Dual™ cells were cultured in the presence of 30 µM of TDI-6570 or G140, an inhibitor of human cGAS. After 3 hours of incubation, 1 µg/ml of G3-YSD, a specific cGAS agonist, complexed with LyoVec™ (LV), was added to the cells. After overnight incubation, the IRF response was assessed using the QUANTI‑Luc™ 4 detection reagent. Data are shown as a percentage (%) of maximal activation (mean +SEM).

Specifications

Synonym: 1-(7-chloro-6-fluoro-5-methyl-1,3,4,5-tetrahydro-2H-pyrido[4,3-b]indol-2-yl)-2-hydroxyethan-1-one

Formula: C₁₄H₁₄CIFN₂O₂

Molecular weight: 296.7 g/mol

Solubility: 5 mg/ml in DMSO. Product may require heating to 37°C for complete dissolution

Working concentration: 0.01 - 1 µM (depending on the agonist; see VDS for more detail)

Quality control:

• Purity ≥ 95% (UHPLC)
• Inhibition of cGAS has been confirmed 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

TDI-6570 is available in two quantities:

• inh-tdi6570-1: 2 mg
• inh-tdi6570-2: 50 mg

TDI-6570 is shipped at room temperature.

 Upon receipt, store at -20°C.

 The resuspended product is stable for 6 months when properly stored.

 Avoid repeated freeze-thaw cycles.

Details

cGAS - Cyclic GMP-AMP synthase

Cyclic GMP-AMP synthase (cGAS, cGAMP synthase) is a critical cytosolic DNA sensor that triggers innate immune responses through the production of type I interferons (IFNs) [1]. In response to cytosolic double‑stranded DNA (dsDNA), cGAS produces the cyclic dinucleotide (CDN) 2’3’-cGAMP.
CDNs bind directly to STING, leading to TBK1‑IRF3-mediated activation of IFN-stimulated response elements (ISRE) in the promoters of IFN-stimulated genes (ISG). The most potent agonist of human STING is 2’3’-cGAMP [2,3].

References:

1. Sun L. et al., 2013. Cyclic GMP-AMP synthase is a cytosolic DNA sensor that activates the type I interferon pathway. Science 339(6121):786-91.
2. Gao P. et al., 2013. Cyclic [G(2’,5’)pA(3’,5’)p] is the metazoan second messenger produced by DNA-activated cyclic GMP-AMP synthase. Cell. 153(5):1094-107.
3. Ablasser A. et al., 2013. cGAS produces a 2’-5’-linked cyclic dinucleotide second messenger that activates STING. Nature. 498(7454):380-4.

Chemical structure of TDI-6570