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PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Copy numbers of JEV RNA were normalised to GAPDH levels using comparative cycle threshold values (2) determined in parallel.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
The following primer sets were used for amplification.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Specifically, the primers were designed against the 3′ untranslated region of the JEV SA14 strain (GenBank accession number: U14163.1).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
JEV: forward 5′-CCCTCAGAACCGTCTCGGAA-3′, reverse 5′-CTATTCCCAGGTGTCAATATGCTGT-3′; GAPDH: forward 5′-TGGGCTACACTGAGCACCAG-3′, reverse 5′-AAGTGGTCGTTGAGGGCAAT-3′. The assay was conducted as previously described .
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Following collection in RIPA buffer (Thermo Fisher Scientific), cells were lysed by sonication and denatured by boiling.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Protein samples were normalized by concentration, resolved by 10% SDS-PAGE, and electrotransferred onto PVDF membranes (Bio-Rad, Hercules, CA, USA).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Subsequently, the membranes were blocked with 5% skimmed milk for 2 h at room temperature prior to incubation with the specified primary and HRP-conjugated secondary antibodies.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Protein bands were visualised with the ECL Plus enhanced chemiluminescence detection reagents (PerkinElmer Life Sciences, Waltham, MA, USA), depending on signal intensity.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
The assay was conducted as previously described .
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
At 48 h post-transfection with the indicated plasmids, cells were harvested from 6-well plates.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Cells were lysed on ice for 4 h using a lysis buffer composed of 50 mM Tris (pH 7.4), 150 mM NaCl, 1 mM EDTA, 1% Triton X-100, 10% glycerol, 10 µg/mL leupeptin, 10 µg/mL aprotinin, and 2 mM PMSF.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Following centrifugation of cell lysates at 13,000 rpm for 10 min, the resulting supernatants were incubated for 1 h with 1 µg of either anti-GSPT1 antibody or a rabbit IgG isotype control (GeneTex, GTX213110-01).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Subsequently, 20 µL of protein G agarose beads (Roche, Basel, Switzerland) were added, and the mixture was incubated overnight at 4 °C with gentle rotation.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
After centrifugation, pellets were washed with lysis buffer, and target proteins were detected by Western blotting using specific antibodies.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
To elucidate the stage of the viral life cycle targeted by CC-90009, JEV-infected SH-SY5Y cells (MOI = 0.5) were treated with 10 µM compound at various time points relative to infection, ranging from 4 h pre-infection to 24 h post-infection at 4 h intervals.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
All infections and treatments were carried out at 37 °C.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Viral infection levels were quantified by IF.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
One-day-old Institute of Cancer research suckling mice were subcutaneously inoculated with JEV at a dose of 4 × 10 plaque-forming units per mouse.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Mice were subsequently administered CC-90009 (20 mg/kg) subcutaneously once daily for five consecutive days.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
The compound was formulated in a vehicle containing dimethyl sulfoxide (DMSO) and 20% sulfobutylether-β-cyclodextrin (HY-17031, MedChemExpress) in saline (10:90, v/v).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Control-infected mice received the same volume of DMSO and 20% sulfobutylether-β-cyclodextrin.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
The survival rates were assessed daily until 14 days post-infection.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Organs and tissues were collected from euthanised mice at the indicated time points and fixed with 4% paraformaldehyde (Servicebio, Wuhan, China) at 4 °C for 24 h. After fixation, tissues were subjected to histopathological and immunohistochemical analyses.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
All data represent the arithmetic mean ± standard deviation (SD) of a minimum of three independent replicates.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Two-group comparisons were assessed by Student’s t-test, while differences across multiple groups were evaluated using one-way ANOVA with Bonferroni’s correction for post hoc testing, implemented in GraphPad Prism 9.0 (GraphPad Software, San Diego, CA, USA).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
A p-value < 0.05 was considered statistically significant.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
To investigate the antiviral activity of TPD-based compounds against JEV infection in SH-SY5Y cells, we selected five clinically advanced compounds: CC-90009; CC-92480, a phase III anti-myeloma CELMoD; NVP-DKY709, a phase I anti-tumour CELMoD targeting Ikaros family zinc finger protein 2; ARV-110, a phase II androgen receptor targeting PROTAC; and ARV-471, a phase II oestrogen receptor PROTAC for breast cancer.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
SH-SY5Y cells were co-treated with JEV and each compound, followed by assessment of their effects on viral infectivity.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Screening experiments revealed that CC-90009 significantly inhibited JEV infection in SH-SY5Y cells, whereas the other compounds showed negligible anti-JEV activity (Figure 1A).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Further investigations across a broad concentration range confirmed CC-90009′s anti-JEV activity and cytotoxicity.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
As shown in Figure 1B–D, it exerted a dose-dependent inhibitory effect on JEV infection with a 50% maximal inhibitory concentration (IC50) of 3.847 μM and a 50% cytotoxic concentration (CC50) of 333.9 μM, highlighting its potential as a promising antiviral agent.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
To identify the stage of the JEV lifecycle inhibited by CC-90009, a time-of-addition assay was performed in which the compound was administered to infected SH-SY5Y cells at various times relative to infection.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
As shown in Figure 2A,B, compared with CQ, a well-known viral entry inhibitor, CC-90009 exhibited significant suppressive activity across all therapeutic windows except pretreatment, suggesting that CC-90009 might affect both viral entry and post-entry stages.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
JEV entry mainly comprises binding and endocytosis.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
We initially examined the role of CC-90009 in the viral binding process.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
SH-SY5Y cells were co-incubated with JEV and CC-90009 at the indicated concentrations for 1.5 h on ice.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
The results indicated that CC-90009 did not affect JEV infectivity during the binding stage in SH-SY5Y cells (Figure 2C).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
In contrast, treatment with the positive control inhibitor heparin resulted in a significant reduction in viral infection.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
We next investigated whether CC-90009 influences viral endocytosis.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
It is well established that JEV employs a caveolin-dependent pathway for entry into neuronal cells .
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Given this established mechanism, we employed RT-qPCR to assess whether CC-90009 impairs JEV entry via this route.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Following a 1.5 h incubation of SH-SY5Y cells with the virus on ice, the supernatant was replaced with fresh medium containing CC-90009 prior to a further 1 h incubation at 37 °C.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
After treatment with proteinase K to remove uninternalised virus, intracellular JEV was quantified.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Unlike the positive control nystatin, CC-90009 did not reduce JEV RNA levels, indicating that CC-90009 does not affect viral endocytosis (Figure 2D).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
The above-mentioned results demonstrated that CC-90009 does not affect JEV entry.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
We therefore investigated whether CC-90009 impacts post-entry stages of JEV infection.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Following endocytosis, JEV first translates viral non-structural proteins, which then assemble into replication complexes on the endoplasmic reticulum to facilitate viral RNA replication.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
To determine if CC-90009 affects JEV translation and replication, SH-SY5Y cells were treated with CC-90009 immediately following JEV infection to evaluate its effects on viral RNA accumulation and non-structural protein expression during a 24 h time course.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
At 6 h post-infection, CC-90009 mildly decreased JEV RNA accumulation.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
However, from 12 to 24 h post-infection, CC-90009 significantly reduced JEV RNA accumulation (Figure 3A).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
CC-90009 also significantly diminished the accumulation of GSPT1 and JEV non-structural proteins compared to the DMSO-treated control at 24 h post-infection.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Notably, the inhibitory effect of CC-90009 on NS5 protein levels was the most prominent (Figure 3B).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
CC-90009 functions as an E3 ubiquitin ligase modulator by selectively recruiting GSPT1 to the CRL4–CRBN complex, leading to its targeted ubiquitination and subsequent degradation.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
To elucidate the role of GSPT1 in JEV replication and translation, siRNA-mediated knockdown (KD) was employed to assess its impact on both viral RNA accumulation and non-structural proteins expression.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Compared with the control group, GSPT1-KD did not significantly suppress JEV RNA levels (Figure 4A), but led to a reduction in the abundance of JEV non-structural proteins (Figure 4B).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
This finding aligns with the established role of GSPT1 as an essential constituent of the eukaryotic translation termination complex (eukaryotic release factor 1/eukaryotic release factor 3) .
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Given the subtle impact on JEV RNA accumulation but a decrease in JEV protein levels, we reason that GSPT1 may support JEV infection by facilitating viral protein translation.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
In contrast to siRNA-mediated GSPT1 depletion, treatment with CC-90009 suppressed the accumulation of JEV RNA following infection, indicating a fundamental defect in JEV RNA synthesis.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
We initially investigated a potential physical interaction between GSPT1 and the JEV NS5 protein using co-IP. (
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Figure 5A).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Furthermore, treatment with CC-90009 significantly enhanced the ubiquitination of GSPT1, whereas the ubiquitination level of JEV NS5 was unaffected (Figure 5B).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Collectively, we hypothesize that CC-90009-mediated tethering of the E3 ligase to GSPT1 may lead to the concomitant degradation of the bound JEV NS5 protein.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
To validate this hypothesis, cells overexpressing GSPT1 and NS5 were treated with either CC-90009 or the proteasome inhibitor MG132, and subsequent alterations in protein levels were examined.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Treatment with CC-90009 alone reduced the levels of both GSPT1 and NS5, whereas MG132 alone had no significant effect.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
However, co-treatment with MG132 abrogated the degradation induced by CC-90009, restoring protein levels to those observed with MG132 treatment alone (Figure 5C).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Furthermore, CRBN-KD attenuated the CC-90009-induced degradation of both GSPT1 and JEV NS5 (Figure 5D).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
These results suggest that the degradation of both GSPT1 and NS5 following CC-90009 treatment is mediated by the proteasome pathway.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Consequently, diminished levels of JEV NS5 are likely to result in a global suppression of viral RNA synthesis.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Collectively, our findings demonstrate that CC-90009 exhibits potent anti-JEV activity in SH-SY5Y cells.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
We next extended our analysis to determine whether the antiviral activity of CC-90009 extends to other mosquito-borne viruses.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
As shown in Figure 6A, CC-90009 treatment potently suppressed infections with both CHIKV and WNV in SH-SY5Y cells in a dose-dependent manner.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Based on the IC50 values, CC-90009 exhibited the strongest antiviral activity against CHIKV (IC50 = 10.6 μM), followed by WNV (IC50 = 23.16 μM).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Furthermore, time-window assays revealed that CC-90009 predominantly targets post-entry stages of both WNV and CHIKV infection (Figure 6B).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Co-IP assays confirmed that GSPT1 physically interacts with NS5 of WNV and nsP4 of CHIKV (Figure 6C).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
To evaluate the in vivo antiviral efficacy of CC-90009, we examined its protective effect against JEV infection in a murine model.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Suckling Institute of Cancer Research mice were inoculated subcutaneously with a lethal dose of JEV and subsequently administered either DMSO or CC-90009.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Survival was monitored daily.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Mice in the JEV-infected, DMSO-treated group began exhibiting clinical signs—such as generalised tremors and unilateral limb paralysis—at three days post-infection.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Mortality reached 83.3% (10/12) between four and seven days post-infection (Figure 7A).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
In contrast, CC-90009 treatment significantly alleviated symptoms and reduced the mortality rate to 38.5% (5/13).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Mice subjected to repeated CC-90009 treatment exhibited a markedly lower viral load in brain tissue than those in the DMSO-treated control group. (
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Figure 7B).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Further analysis using hematoxylin and eosin (H&E) staining revealed that the CC-90009-treated group exhibited less severe histopathological damage in brain tissues compared with JEV-infected controls (Figure 7C).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Additionally, immunohistochemical examination of mouse brain tissue showed high abundance of viral particles in the control group, whereas CC-90009 administration notably reduced the number of viral particles (Figure 7D).
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
In this study, we found that CC-90009 acts as a broad-spectrum antiviral agent, inhibiting infections by JEV, WNV, and CHIKV in SH-SY5Y cells.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Mechanistically, CC-90009 suppresses JEV translation processes and impairs viral genome replication by interfering with the protein levels of JEV NS5.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
In vivo experiments demonstrated that CC-90009 significantly protects suckling mice from JEV infection-induced mortality.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Here, we report for the first time that CC-90009 treatment induces the degradation of both GSPT1 and JEV NS5.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
The NS5 protein is the largest and most conserved enzyme encoded by flaviviruses.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
It is characterized by two functional domains: an N-terminal methyltransferase and a C-terminal RdRp .
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
The RdRps of flaviviruses are structurally similar: JEV and WNV share 70% identity with Zika virus, while Dengue virus (DENV)-2 and DENV-3 share 76% and 81% identity with Zika virus, respectively .
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Based on the conservation of NS5 and its similarity between JEV and WNV, CC-90009 effectively inhibits both flaviviruses, most likely by targeting the NS5 protein of each virus.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
In the case of CHIKV, a member of the Alphavirus genus, its nsP4 protein also exhibits RdRp activity ; however, the precise mechanism of action of CC-90009, including its potential targeting of nsP4, remains to be elucidated.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Collectively, these findings suggest the potential for developing CC-90009-based therapeutics against JE by targeting the JEV RdRp for degradation.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Our results demonstrated that CC-90009 treatment inhibited JEV infection in neuronal cells, with a significant reduction in NS5 protein levels.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
When proteasome function was inhibited by MG132, NS5 degradation was abrogated.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
Furthermore, CC-90009 failed to degrade NS5 upon CRBN inhibition.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
These findings collectively indicate that CC-90009 exerts its function by targeting NS5 for degradation via the proteasome pathway.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
However, we did not detect ubiquitination of NS5, suggesting that NS5 degradation may not occur through direct ubiquitination; instead, it might be indirectly targeted for proteasomal degradation together with GSPT1.
PMC12736548
CC-90009, a Cereblon E3 Ligase Modulator, Exhibits Antiviral Efficacy Against JEV In Vitro and In Vivo via Targeted Degradation of GSPT1 and Viral NS5 Protein
By reprogramming the substrate specificity of the CRL4–CRBN E3 ligase, CC-90009 may convert JEV NS5 into a neosubstrate, thereby targeting it for degradation.