Zbtb18 Deficiency Impairs the Hippocampal Development and Neurite Growth

Previous studies of the transcription factor Zbtb18 have primarily focused on its role in cortical development, whereas its function during hippocampal development remains poorly understood. In this study, we investigated the role of Zbtb18 in mouse hippocampal development using histological, transcriptomic, and functional approaches. Immunostaining demonstrated that Zbtb18 was partially overlapped with the neural progenitor marker Pax6, intermediate progenitor marker Tbr2, postmitotic neuronal marker Tbr1, and neuronal marker NeuN in the hippocampal primordium from embryonic day 13.5. Loss of Zbtb18 was associated with pronounced hippocampal malformations, including Dentate Gyrus disorganization and altered cellular architecture. Single-nucleus RNA sequencing at embryonic day 18.5 suggested alterations in neuronal composition within the Cornu Ammonis and Dentate Gyrus regions, accompanied by increased Prox1 expression and abnormal progenitor cell proliferation. Pathway analyses identified transcriptional alterations associated with neurogenesis, neuronal differentiation, neuronal morphogenesis, and cAMP signaling. Consistent with these findings, primary hippocampal neurons derived from Zbtb18-deficient embryos exhibited reduced longest neurite length and total neurite length in vitro. Pharmacological activation of cAMP signaling with forskolin partially improved neurite growth in Zbtb18-deficient neurons. Together, these findings suggest that Zbtb18 regulates hippocampal development and neurite growth, in which the cAMP signaling pathway is involved in the neuronal morphological defect.