A novel inhibitor rescues cerebellar defects in a zebrafish model of Down syndrome–associated kinase Dyrk1A overexpression

Abstract

The highly conserved dual-specificity tyrosine phosphorylation–regulated kinase 1A (Dyrk1A) plays crucial roles during central nervous system development and homeostasis. Furthermore, its hyperactivity is considered responsible for some neurological defects in individuals with Down syndrome. We set out to establish a zebrafish model expressing human Dyrk1A that could be further used to characterize the interaction between Dyrk1A and neurological phenotypes. First, we revealed the prominent expression of dyrk1a homologs in cerebellar neurons in the zebrafish larval and adult brains. Overexpression of human dyrk1a in postmitotic cerebellar Purkinje neurons resulted in a structural misorganization of the Purkinje cells in cerebellar hemispheres and a compaction of this cell population. This impaired Purkinje cell organization was progressive, leading to an age-dependent dispersal of Purkinje neurons throughout the cerebellar molecular layer with larval swim deficits resulting in miscoordination of swimming and reduced exploratory behavior in aged adults. We also found that the structural misorganization of the larval Purkinje cell layer could be rescued by pharmacological treatment with Dyrk1A inhibitors. We further reveal the in vivo efficiency of a novel selective Dyrk1A inhibitor, KuFal194. These findings demonstrate that the zebrafish is a well-suited vertebrate organism to genetically model severe neurological diseases with single cell type specificity. Such models can be used to relate molecular malfunction to cellular deficits, impaired tissue formation, and organismal behavior and can also be used for pharmacological compound testing and validation.

Differential maturation and chaperone dependence of the paralogous protein kinases DYRK1A and DYRK1B

“…We asked whether the maturation of DYRK1B orthologs from other vertebrate classes was also compromised in the absence of eukaryotic chaperones. To this end, we chose DYRK1B from zebrafish ( Danio rerio ) 31 and African clawed frog ( Xenopus laevis ) 32 as representatives for bony fish and amphibians, and included zebrafish DYRK1Aa 33 for further comparison. Strep-tag fusion constructs were designed as illustrated in Fig.…”

Lifelong regeneration of cerebellar Purkinje neurons after induced cell ablation in zebrafish

“…Functional PC regeneration implies the restoration of behavior caused by adult PC loss known to result in compromised exploration (Buchberger et al, 2021; Elsaey et al, 2021). In the novel tank test, adult zebrafish initially remain close to the bottom, but progressively start to explore the new environment (Egan et al, 2009; Fontana et al, 2021).…”

“…A recently established zebrafish model with compromised adult PC functions displayed defects in both exploratory as well as locomotor behavior (Buchberger et al, 2021).…”

“…A recently established zebrafish model with compromised adult PC functions displayed defects in both exploratory as well as locomotor behavior (Buchberger et al, 2021). Interestingly, between PC-ablated PC-ATTAC TM and control specimens speed of swimming and distances travelled were not significantly different, but only exploratory behavior.…”

Proteomic profiling reveals mitochondrial dysfunction in the cerebellum of transgenic mice overexpressing DYRK1A, a Down syndrome candidate gene

“…DYRK1A is expressed at high levels in the cerebellum (Martí et al, 2003), and mouse models with altered Dyrk1A expression exhibit altered motor abilities (Altafaj et al, 2001;Fotaki et al, 2002;Martínez de Lagrán et al, 2004). Overexpression of human Dyrk1A in postmitotic cerebellar Purkinje neurons in zebrafish resulted in a structural disorganization of the Purkinje cells in cerebellar hemispheres and a compaction of this cell population that could be rescued by a novel selective DYRK1A inhibitor, KuFal194 (Buchberger et al, 2021). Similarly, normalization of the dosage of Dyrk1A in the partial trisomic Ts65Dn DS mouse model (Ts65Dn +/+/− with only two copies of Dyrk1A), rescues granular and Purkinje cell densities and the size of the granular and molecular layers (García-Cerro et al, 2018).…”