Temporal manipulation of Cdkl5 reveals essential postdevelopmental functions and reversible CDKL5 deficiency disorder–related deficits
Barbara Terzic, … , Marc V. Fuccillo, Zhaolan Zhou
Barbara Terzic, … , Marc V. Fuccillo, Zhaolan Zhou
Published October 15, 2021
Citation Information: J Clin Invest. 2021;131(20):e143655. https://doi.org/10.1172/JCI143655.
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Research Article Development Neuroscience

Temporal manipulation of Cdkl5 reveals essential postdevelopmental functions and reversible CDKL5 deficiency disorder–related deficits

Abstract

CDKL5 deficiency disorder (CDD) is an early onset, neurodevelopmental syndrome associated with pathogenic variants in the X-linked gene encoding cyclin-dependent kinase-like 5 (CDKL5). CDKL5 has been implicated in neuronal synapse maturation, yet its postdevelopmental necessity and the reversibility of CDD-associated impairments remain unknown. We temporally manipulated endogenous Cdkl5 expression in male mice and found that postdevelopmental loss of CDKL5 disrupts numerous behavioral domains, hippocampal circuit communication, and dendritic spine morphology, demonstrating an indispensable role for CDKL5 in the adult brain. Accordingly, restoration of Cdkl5 after the early stages of brain development using a conditional rescue mouse model ameliorated CDD-related behavioral impairments and aberrant NMDA receptor signaling. These findings highlight the requirement of CDKL5 beyond early development, underscore the potential for disease reversal in CDD, and suggest that a broad therapeutic time window exists for potential treatment of CDD-related deficits.

Authors

Barbara Terzic, M. Felicia Davatolhagh, Yugong Ho, Sheng Tang, Yu-Ting Liu, Zijie Xia, Yue Cui, Marc V. Fuccillo, Zhaolan Zhou

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Figure 1

Postdevelopmental loss of CDKL5 disrupts multiple behavioral domains in mice.

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Postdevelopmental loss of CDKL5 disrupts multiple behavioral domains in ...
(A) Top: representative Western blot showing CDKL5 and actin protein expression from forebrain tissues of WT mice across multiple ages, where knockout tissue was referenced for antibody specificity; bottom: quantification of CDKL5 protein, normalized to actin, and plotted relative to P0 levels (mixed effects analysis; n = 4). (B) Top: tamoxifen and experimental schedule; bottom: representative Western blot and quantification of CDKL5 protein expression in forebrain tissues of all experimental mice. Values were normalized to actin and plotted relative to CreER-only CDKL5 levels. (C) AKO mice spend significantly more time in the open arm of the elevated zero maze assay compared with floxed and CreER littermates. (D) AKO mice travel significantly more distance than floxed littermates in the open-field assay. (E) AKO mice spend significantly less time than floxed and CreER littermates sniffing and (F) directly interacting with a novel stimulus mouse during the 3-chambered social choice test. (G) AKO mice spend more time grooming or digging in a home cage–like environment than floxed and CreER littermates. (H) AKO mice spend significantly less time freezing compared with floxed and CreER littermates when returned to the fear-conditioning testing chamber (contextual) and (I) upon hearing the footshock-associated tone (cue). (J) AKO mice take significantly more time to fall from an accelerating, rotating rod than floxed and CreER littermates. For all panels, floxed, n = 13; CreER, n = 19; AKO, n = 23 where all genotypes received tamoxifen. One-way ANOVA test with Holm-Šidák post hoc test, except as follows: open field, unpaired, 2-tailed t test; 3-chambered social choice assay and repetitive behaviors, Kruskal-Wallis test with Dunn’s multiple-comparison test; rotarod, 2-way repeated measures ANOVA with Šidák’s multiple-comparison test. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. Data are represented as mean ± SEM. Full-scan Western blots of all samples are available in the supplemental material.