Activity-dependent neuroprotective protein deficiency models synaptic and developmental phenotypes of autism-like syndrome
Gal Hacohen-Kleiman, … , R. Anne McKinney, Illana Gozes
Gal Hacohen-Kleiman, … , R. Anne McKinney, Illana Gozes
Published August 14, 2018
Citation Information: J Clin Invest. 2018;128(11):4956-4969. https://doi.org/10.1172/JCI98199.
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Research Article

Activity-dependent neuroprotective protein deficiency models synaptic and developmental phenotypes of autism-like syndrome

Abstract

Previous findings showed that in mice, complete knockout of activity-dependent neuroprotective protein (ADNP) abolishes brain formation, while haploinsufficiency (Adnp+/–) causes cognitive impairments. We hypothesized that mutations in ADNP lead to a developmental/autistic syndrome in children. Indeed, recent phenotypic characterization of children harboring ADNP mutations (ADNP syndrome children) revealed global developmental delays and intellectual disabilities, including speech and motor dysfunctions. Mechanistically, ADNP includes a SIP motif embedded in the ADNP-derived snippet drug candidate NAP (NAPVSIPQ, also known as CP201), which binds to microtubule end–binding protein 3, essential for dendritic spine formation. Here, we established a unique neuronal membrane–tagged, GFP-expressing Adnp+/– mouse line allowing in vivo synaptic pathology quantification. We discovered that Adnp deficiency reduced dendritic spine density and altered synaptic gene expression, both of which were partly ameliorated by NAP treatment. Adnp+/–mice further exhibited global developmental delays, vocalization impediments, gait and motor dysfunctions, and social and object memory impairments, all of which were partially reversed by daily NAP administration (systemic/nasal). In conclusion, we have connected ADNP-related synaptic pathology to developmental and behavioral outcomes, establishing NAP in vivo target engagement and identifying potential biomarkers. Together, these studies pave a path toward the clinical development of NAP (CP201) for the treatment of ADNP syndrome.

Authors

Gal Hacohen-Kleiman, Shlomo Sragovich, Gidon Karmon, Andy Y. L. Gao, Iris Grigg, Metsada Pasmanik-Chor, Albert Le, Vlasta Korenková, R. Anne McKinney, Illana Gozes

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Figure 5

Adnp haploinsufficiency causes significant decreases in USVs and delays in developmental milestones, partially reversed with daily NAP treatment.

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Adnp haploinsufficiency causes significant decreases in USVs and delays...
(A) For USV measurement, a 2-way ANOVA with Tukey’s post hoc test was performed. Main treatment [F(1,460) = 26.095, P < 0.001] and interaction [F(1,460) = 17.463, P < 0.001] effects were found. Adnp+/– pups produced significantly fewer USVs per minute compared with Adnp+/+ pups (*P < 0.05), with NAP increasing vocalization production by 3-fold compared with Adnp+/– mice (***P < 0.001) and by 2-fold compared with Adnp+/+ mice (***P < 0.001, Mann-Whitney U test). When comparing sexes (inset graph), NAP treatment had the most profound effect on Adnp+/– males (4-fold increase) compared with females (2-fold increase) (#P < 0.05, Mann-Whitney U test). Results are presented as the mean ± SEM USVs per minute (males: Adnp+/+ n = 11, Adnp+/– n = 9, Adnp+/– NAP, n = 6; females: Adnp+/+ n = 11, Adnp+/– n = 8, Adnp+/– NAP, n = 5, 6 USV calls per mouse). (B–D) For developmental milestone measurements, a 2-way ANOVA with Tukey’s post hoc test was performed, with data expressed as the mean ± SEM of the first neonatal day of success in the test (Adnp+/+ n = 35–51, Adnp+/– n = 19–29, Adnp+/– NAP, n = 28–43; exact numbers are detailed in Supplemental Table 16). For the ear twitch reflex, a significant main genotype effect was found [F(1,109) = 11.851, P < 0.001], with Adnp+/– pups displaying a significantly earlier response compared with Adnp+/+ pups (*P < 0.05). For the air righting reflex, a significant main treatment effect was found [F(1,164) = 24.838, P < 0.001], implying that NAP-treated Adnp+/– pups acquired an air righting reflex significantly earlier than did Adnp+/– pups (**P < 0.01). For negative geotaxis, significant genotype [F(1,163) = 36.780, P < 0.001] and treatment [F(1,163) = 7.684, P = 0.006] effects were found. Adnp+/– mice presented a significant delay in negative geotaxis compared with Adnp+/+ littermates (***P < 0.001), with NAP treatment significantly improving the phenotype (**P < 0.01). (A–D) Adnp+/+ data are reshown in Supplemental Figure 10, A–D.