DYRK1A, short for Dual-specificity tyrosine phosphorylation-regulated kinase 1A, is an evolutionarily conserved protein kinase and a key member of the DYRK family [3]. It plays essential roles in various biological processes, with its dosage being critical in the central nervous system during development and aging [2]. It is involved in pathways related to cell cycle regulation, synaptic plasticity, and is positioned at the crossroads of many important processes [2]. Genetic models such as Drosophila, zebrafish, and mice have been crucial for studying DYRK1A [2].

DYRK1A is located in the region q22.2 of chromosome 21 and is involved in the pathogenesis of Down syndrome. Its overexpression promotes the accumulation of amyloid beta (Aβ) peptides, leading to Tau hyperphosphorylation and neurodegeneration, which is relevant to Alzheimer's disease [1]. In adult mice with myocardial infarction, both conditional deletion (KO/CKO mouse models) and pharmacological inhibition of DYRK1A induced cardiomyocyte cell cycle activation and cardiac repair, with improved cardiac function. This was associated with epigenetic modifications like increased deposition of trimethylated histone 3 Lys4 (H3K4me3) and acetylated histone 3 Lys27 (H3K27ac) on the promoter regions of genes governing cell proliferation [4]. Analyses of mouse models with Dyrk1a dosage imbalance (overexpression and underexpression) show skeletal deficits and abnormalities, and normalization of Dyrk1a copy number in a trisomic animal rescues some skeletal health parameters, while reduction in a euploid animal results in altered skeletal health measurements [5].

In conclusion, DYRK1A is essential for normal biological processes, especially in the central nervous system, and its dysregulation is linked to multiple diseases including neurodegenerative diseases, Down syndrome, and disorders related to the heart and skeleton. Studies using KO/CKO mouse models have significantly contributed to understanding its role in these disease conditions, providing insights into potential therapeutic strategies [2,4,5].