Name: ISRIB (trans-isomer)
Brand: Adooq Bioscience
SKU: A14302
Availability: InStock
Rating: 5 (5 reviews)

Biological Activity

Bioactivity / Mechanism

ISRIB (trans-isomer) activates eIF2B-dependent nucleotide exchange. In a purified-factor assay, 100 nM ISRIB shortened the GDP-release half-time from 3.2 to 1.1 min. It did not enable exchange on phosphorylated eIF2 alone, and stimulation weakened at a 1:1 ratio of unphosphorylated to phosphorylated eIF2. [1]

Literature-reported observations and conditions; not Adooq-tested protocols or general treatment recommendations.

Target & Activity

Target	Activity	Value
PERK		5 nM

In Vitro Studies

In stressed HEK293T reporter cells, synthesized trans-ISRIB inhibited ATF4-luciferase activity with a reported IC50 of 5 nM, compared with 600 nM for cis-ISRIB. These values describe the cellular reporter assay. [2]

ISRIB effects depend on cellular context. In HEK293T cells, 200 nM ISRIB combined with tunicamycin reduced subsequent colony formation more than tunicamycin alone; ISRIB alone did not reduce colony formation in that assay. [2]

In primary mouse alveolar organoid cultures, 1 µM ISRIB increased organoid diameter in pooled-sex analyses of control and Ndufs2-deficient AT2 cells. Colony-forming efficiency showed no significant overall difference. Diameter served as a proxy for differentiation. [3]

ISRIB accelerates eIF2B-dependent GDP release with a phosphorylation-dependent limit

Biochemical assay · Purified human eIF2 and partially purified rabbit-reticulocyte eIF2B; radiolabeled GDP-release assay [1]

At 100 nM, ISRIB accelerated eIF2B-dependent GDP release. It did not accelerate intrinsic release or make phosphorylated eIF2 a usable substrate; stimulation was weak at the 1:1 eIF2:eIF2-P ratio.

Measured endpoints — not treatment concentrations
Endpoint	Reported result	Reference
eIF2B-dependent GDP-release half-time	t1/2 3.2 min without ISRIB; 1.1 min with 100 nM ISRIB	[1]
GDP-release response with phosphorylated eIF2	t1/2 and qualitative substrate response 3:1 eIF2:eIF2-P: 6.7 min without ISRIB versus 2.7 min with ISRIB; 1:1: 6.4 min versus 5.3 min. No stimulation with eIF2-P alone.	[1]

Literature-Reported Treatment Conditions

Treatment concentration: 100 nM ISRIB
Exposure duration: GDP release followed over 0–20 min
Method: Cell-free filter-binding assay with unlabeled GDP chase; first-order exponential-decay fitting
Co-treatment: eIF2B or buffer; unphosphorylated eIF2, eIF2-P, or mixtures at 3:1 and 1:1
Reported limits: ISRIB solvent is not specified in the GDP-dissociation subsection. Starting phosphorylation fraction of the purified eIF2 preparation was unknown to the authors.

Methods and source locations

Compound reported in the paper: ISRIB (trans-isomer); Compound label in the paper: ISRIB-A1, trans-1,4-cyclohexyl parent compound

Applies to the reported experimental material and model; does not establish present Adooq lot performance.

Figure 5A–D and Figure 5 supplement 1; Results: ISRIB enhances the GEF activity of eIF2B; Methods: GDP dissociation assay; Discussion

eIF2B-dependent GDP-release half-time: [3H]-GDP filter binding; Figure 5A N = 3, error bars ± SD — Figure 5A; associated Results

GDP-release response with phosphorylated eIF2: Mixture assay; Figure 5B–D N = 2, error bars ± SD — Figure 5B–D; associated Results

Stereoisomer comparison in an ATF4 translation reporter

Cell-based study · HEK293T cells expressing an ATF4 5′-UTR firefly-luciferase reporter [2]

Synthesized trans-ISRIB inhibited stress-induced reporter activity more potently than the cis-isomer. The reported IC50 is a cellular reporter endpoint.

Measured endpoints — not treatment concentrations
Endpoint	Reported result	Reference
Inhibition of stress-induced ATF4-luciferase reporter	IC50 trans-ISRIB: 5 nM; cis-ISRIB: 600 nM	[2]

Literature-Reported Treatment Conditions

Treatment concentration: ISRIB concentration-response series; individual doses are plotted rather than enumerated in the caption
Exposure duration: 7 h
Method: ATF4-luciferase reporter
Co-treatment: Tunicamycin 2 µg/mL to induce ER stress
Reported limits: Final vehicle concentration for Figure 2B is not specified in its caption; do not substitute conditions from the earlier library screen.

Methods and source locations

Compound reported in the paper: ISRIB (trans-isomer); Compound label in the paper: Synthesized trans-ISRIB; cis-ISRIB comparator

Applies to the reported experimental material and model; does not establish present Adooq lot performance.

Figure 2A–B; Results: A symmetric bisglycolamide, ISRIB, is a potent inhibitor of PERK signaling; Materials and methods: cell culture, reporter luminescence; Synthesis of ISRIB identity

Inhibition of stress-induced ATF4-luciferase reporter: N = 2; mean ± SD. Labels in Figure 2B and Results; values are not estimated from curves. — Figure 2B and adjacent Results

ISRIB reduces clonogenic survival after ER stress

Cell-based study · HEK293T cells, post-treatment clonal outgrowth visualized with crystal violet [2]

ISRIB alone did not reduce colony formation in this assay. Combined ISRIB and tunicamycin produced fewer and smaller colonies than tunicamycin alone.

Measured endpoints — not treatment concentrations
Endpoint	Reported result	Reference
Clonal colony number and size after treatment	qualitative colony formation ISRIB alone: no apparent reduction; ISRIB plus tunicamycin: reduced colony number and size relative to tunicamycin alone	[2]

Literature-Reported Treatment Conditions

Treatment concentration: 200 nM ISRIB
Exposure duration: 24 h exposure followed by reseeding for clonal outgrowth
Method: Crystal-violet colony visualization following a threefold cell-dilution series
Co-treatment: Tunicamycin 2 µg/mL; single-agent and untreated controls
Reported limits: Post-reseeding outgrowth duration, final vehicle concentration and replicate count are not specified in the Figure 5A caption or associated text reviewed.

Methods and source locations

Compound reported in the paper: ISRIB (trans-isomer); Compound label in the paper: Synthesized trans-ISRIB

Applies to the reported experimental material and model; does not establish present Adooq lot performance.

Figure 5A; Results: ISRIB impairs adaptation to ER-stress; cell-culture methods; trans-ISRIB identity declaration after Figure 2

Clonal colony number and size after treatment: Crystal-violet staining; no numerical colony count or calculated synergy score extracted. — Figure 5A image/caption and associated Results

ISRIB increases organoid diameter without a detected colony-efficiency difference

Cell-based study · AT2 cells from 6-day-old NDUFS2 control and lung-epithelial Ndufs2 conditional-knockout mice, co-cultured with wild-type lung fibroblasts in 3D [3]

ISRIB increased organoid diameter in the pooled-sex comparisons for both genotypes. Colony-forming efficiency showed no significant overall difference. Diameter is a proxy for differentiation in this assay.

Measured endpoints — not treatment concentrations
Endpoint	Reported result	Reference
Organoid diameter, used as a proxy for differentiation	diameter comparison Larger with ISRIB in pooled males and females for both genotypes; control P = 0.0058, cKO P = 0.0018	[3]
Colony-forming efficiency, used as a proxy for proliferation	overall Kruskal–Wallis test P = 0.9652	[3]

Literature-Reported Treatment Conditions

Treatment concentration: 1 µM ISRIB
Exposure duration: Culture imaged after 10 days; ISRIB introduced the day after plating and refreshed every other day
Method: 3D alveolar organoid culture; brightfield and lineage-fluorescence imaging
Vehicle: DMSO comparator
Co-treatment: AT2/fibroblast co-culture in organoid growth medium containing aspartate and asparagine; no other experimental drug comparator in selected panels
Reported limits: Final DMSO percentage and total organoid-level technical-replicate count are not specified in the selected caption/methods.

Methods and source locations

Compound reported in the paper: ISRIB (trans-isomer); Compound label in the paper: ISRIB, AdooQ A14302

Applies to the reported experimental material and model; does not establish present Adooq lot performance.

Extended Data Figure 12a–f; Results paragraph beginning: To determine whether the impaired alveolar epithelial differentiation; Methods: Mice and three-dimensional alveolar organoid culture

Organoid diameter, used as a proxy for differentiation: Šídák multiple-comparison tests; lines denote median; n = 6 mice per genotype (three males and three females), with technical replicates; no diameters estimated from violins. — Extended Data Figure 12a–e and caption

Colony-forming efficiency, used as a proxy for proliferation: No significant overall difference among displayed genotype/treatment groups; this does not establish equivalence or directly measure cell-division rate. — Extended Data Figure 12f and caption

In Vivo Studies

In male mice with bleomycin-associated lung fibrosis, daily intraperitoneal ISRIB at 2.5 mg/kg from day 7 improved lung compliance and reduced collagen and histologic fibrosis at day 28 versus vehicle. The study tested AdooQ A14302 and observed benefit in both young-adult and old cohorts. [4]

Daily ISRIB treatment attenuates bleomycin-associated fibrosis in mice

Animal study · Male C57BL/6J young-adult and old mice with bleomycin-associated pulmonary fibrosis; naïve controls [4]

Compared with vehicle, ISRIB improved lung compliance, lowered collagen and fibrosis scores, and attenuated weight loss in both age groups. Naïve animals did not show detectable changes in the reported baseline endpoints.

Measured endpoints — not treatment concentrations
Endpoint	Reported result	Reference
Histologic fibrosis, lung compliance, collagen and body weight	directional comparison ISRIB versus vehicle after bleomycin: lower fibrosis score and collagen, higher compliance and attenuated weight loss; naïve groups had no detected baseline effect	[4]

Conditions shared by the study groups

Route: Intraperitoneal
Frequency: Daily
Treatment course: Day 7 after bleomycin through day-28 harvest
Vehicle: ISRIB in DMSO stock, diluted with PBS; vehicle-treated comparator

Study groups and reported outcomes
Group / dose	Comparator	Observed result	Reference
Bleomycin plus ISRIB, both age cohorts 2.5 mg/kg ISRIB	Bleomycin plus vehicle; naïve vehicle and naïve ISRIB controls	Improved compliance and lower collagen/histologic fibrosis relative to injured vehicle controls; attenuated weight loss	[4]

Bleomycin plus ISRIB, both age cohorts: Model: Male young-adult and old C57BL/6J mice; Figure 3 ages 3–5 and 18–24 months, respectively; Reported limits: Young-adult age discrepancy between Figure 3 and general methods remains unresolved; no exact effect sizes inferred from graphs.

Methods and source locations

Compound reported in the paper: ISRIB (trans-isomer); Compound label in the paper: ISRIB, AdooQ BioScience LLC A14302

Applies to the reported experimental material and model; does not establish present Adooq lot performance.

Figure 3A–I and associated Results; Materials and Methods: Mice, drug administration, histopathology, fibrosis scores and collagen determination

Histologic fibrosis, lung compliance, collagen and body weight: Blinded histologic scoring; compliance by Flexivent; collagen by picrosirius-red precipitation. Mean ± SEM, 5–7 mice/group; body-weight panels specify five/group. Figure-specific tests include Mann–Whitney with Bonferroni correction and ANOVA with multiple comparisons; *P < 0.05. Caption: representative data from two independent experiments. — Figure 3B–I; associated Results

Bleomycin plus ISRIB, both age cohorts · Figure 3A–I and associated Results; Materials and Methods: Mice, drug administration, histopathology, fibrosis scores and collagen determination

Specifications

Manufacturer	Adooq Bioscience
Actions	Inhibitor
CAS Number	1597403-47-8
Applications	eIF2B activator (integrated stress response inhibitor)
Formula	C₂₂H₂₄Cl₂N₂O₄
Molecular Weight	451.34
SMILES	C1CC(CCC1NC(=O)COC2=CC=C(C=C2)Cl)NC(=O)COC3=CC=C(C=C3)Cl

Storage & Solubility

In Vitro Solubility

Reported Solubility

Solvent	Reported Solubility
DMSO	4 mg/mL (8.86 mM)
Water	Insoluble
Ethanol	Insoluble

Preparing Stock Solutions

Stock preparation is unavailable for this product molecular weight.

Calculated stock concentrations do not establish solvent solubility. Refer to the reported solubility data for experimental guidance.

Storage

Store powder at -20°C, keep desiccated.
In powder form, the chemical is stable for 36 months.
In solution, store at -20°C and use within 1 month to prevent loss of potency. Aliquot to avoid multiple freeze/thaw cycles.

Research References

[1] Carmela Sidrauski, Jordan C Tsai, Martin Kampmann, et al. Pharmacological dimerization and activation of the exchange factor eIF2B antagonizes the integrated stress response eLife (2015). PMID: 25875391 DOI: 10.7554/elife.07314 Source material
[2] Carmela Sidrauski, Diego Acosta-Alvear, Arkady Khoutorsky, et al. Pharmacological brake-release of mRNA translation enhances cognitive memory eLife (2013). PMID: 23741617 DOI: 10.7554/elife.00498 Source material
[3] SeungHye Han, Minho Lee, Youngjin Shin, et al. Mitochondrial integrated stress response controls lung epithelial cell fate Nature (2023). PMID: 37558881 DOI: 10.1038/s41586-023-06423-8 Source material
[4] Satoshi Watanabe, Nikolay S Markov, Ziyan Lu, et al. Resetting proteostasis with ISRIB promotes epithelial differentiation to attenuate pulmonary fibrosis Proceedings of the National Academy of Sciences of the United States of America (2021). PMID: 33972447 DOI: 10.1073/pnas.2101100118 Source material

Publications

5 publications citing this product

Le Xu, .et al. , Cell Stem Cell, 2024, Aug 16:S1934-5909(24)00287-X PMID: 39181129
SeungHye Han, .et al. , Nature, 2023, Aug;620(7975):890-897 PMID: 37558881
Zhou W, .et al. , Research Square, 2023, MAY 03
Satoshi Watanabe, .et al. , Proc Natl Acad Sci U S A, 2021, May 18;118(20) PMID: 33972447
Satoshi Watanabe, .et al. , bioRxiv, 2020, February 27

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ISRIB (trans-isomer)

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