A haploinsufficiency restoration strategy corrects neurobehavioral deficits in Nf1+/– mice
Su Jung Park, … , Steven P. Angus, D. Wade Clapp
Su Jung Park, … , Steven P. Angus, D. Wade Clapp
Published July 1, 2025
Citation Information: J Clin Invest. 2025;135(13):e188932. https://doi.org/10.1172/JCI188932.
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Research Article Genetics Neuroscience

A haploinsufficiency restoration strategy corrects neurobehavioral deficits in Nf1+/– mice

Abstract

Neurofibromatosis type 1 (NF1) is a genetic disorder caused by mutations of the NF1 tumor suppressor gene resulting in the loss of function of neurofibromin, a GTPase-activating protein (GAP) for Ras. While the malignant manifestations of NF1 are associated with loss of heterozygosity of the residual WT allele, the nonmalignant neurodevelopmental sequelae, including autism spectrum disorder (ASD) and/or attention deficit hyperactivity disorder (ADHD) are prevalent morbidities that occur in the setting of neurofibromin haploinsufficiency. We reasoned that augmenting endogenous levels of WT neurofibromin could serve as a potential therapeutic strategy to correct the neurodevelopmental manifestations of NF1. Here, we used a combination of genetic screening and genetically engineered murine models to identify a role for the F-box protein FBXW11 as a regulator of neurofibromin degradation. Disruption of Fbxw11, through germline mutation or targeted genetic manipulation in the nucleus accumbens, increased neurofibromin levels, suppressed Ras-dependent ERK phosphorylation, and corrected social learning deficits and impulsive behaviors in male Nf1+/– mice. Our results demonstrate that preventing the degradation of neurofibromin is a feasible and effective approach to ameliorate the neurodevelopmental phenotypes in a haploinsufficient disease model.

Authors

Su Jung Park, Jodi L. Lukkes, Ka-Kui Chan, Hayley P. Drozd, Callie B. Burgin, Shaomin Qian, Morgan McKenzie Sullivan, Cesar Gabriel Guevara, Nolen Cunningham, Stephanie Arenas, Makenna A. Collins, Jacob Zucker, JinHee Won, Abbi Smith, Li Jiang, Dana K. Mitchell, Steven D. Rhodes, Steven P. Angus, D. Wade Clapp

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Figure 7

Selective deletion of Fbxw11 in the nucleus accumbens rescues cognitive deficits in male Nf1+/– Fbxw11fl/fl mice.

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Selective deletion of Fbxw11 in the nucleus accumbens rescues cognitive ...
(A) Schematic of stereotaxic AAV virus injection. Cohorts of male Nf1+/– Fbxw11fl/fl and control Nf1+/+ Fbxw11fl/fl mice received bilateral injections of AAV-GFP (control, n = 8 mice per genotype) or AAV-Cre-GFP virus (n = 18 mice per genotype) for experiments (after injection). Mice underwent behavioral testing at baseline to confirm the expected deficits. The indicated genotypes and treatments are abbreviated as shown in parentheses for group labeling in C–F. Image created in BioRender. Angus, S. (2025) https://BioRender.com/r74c640 (B) To ensure correct viral injection, IHC was performed to visualize GFP expression at the center of each injection site. A representative image of the injection site at the nucleus accumbens and center points of all injections is shown. (C–F) Studies were performed as in Figure 4. (C) Nf1+/– Fbxw11fl/fl male mice exhibited hyperactivity in the OF task (P < 0.0001) at baseline and following GFP injection (P = 0.0053) compared with WT mice that was reduced in mice receiving CRE (P = 0.0056) as determined by 1-way ANOVA with Dunnett’s multiple-comparison test (mean ± SEM). (D) Nf1+/– Fbxw11fl/fl male mice infected with GFP made more impulsive choices in the DDT when compared with WT mice receiving GFP (P = 0.0001) that was suppressed in the CRE group. P = 0.0001, by 1-way ANOVA with Dunnett’s multiple-comparison test. Data indicate the mean ± SEM. (E) Nf1+/– Fbxw11fl/fl male mice spent more time investigating a novel partner on day 1 (P < 0.0001) but not day 2 (P = 0.1625) at baseline in the SP task. This pattern persisted in Nf1+/– Fbxw11fl/fl male mice receiving GFP, while CRE led to increased interaction time with a novel mouse versus a familiar mouse on day 2 (P < 0.0001). Significance was determined by mixed-effects analysis and Tukey’s multiple-comparison test. Data indicate the mean ± SEM. (F) Nf1+/– Fbxw11fl/fl male mice had a greater number of falls and over-the-edge time at baseline (P = 0.0009 and P < 0.0001, respectively) and after injection with GFP (P < 0.0001 and P = 0.0007, respectively) compared with WT mice in the CAR task. After CRE injection, the number of falls (P = 0.0003) and over-edge time (P = 0.002) for Nf1+/– Fbxw11fl/fl male mice was reduced compared with the GFP-injected cohort (NF1/FBX vs. NF1). Significance was determined by 1-way ANOVA with Dunnett’s multiple-comparison test. Data indicate the mean ± SEM. **P < 0.01, ***P < 0.001, and ****P < 0.0001. ##P < 0.01 and ###P < 0.001, for comparison of CRE-mediated Fbxw11 ablation with control GFP (NF1/FBX to NF1).