Transcription Factor EB Overexpression through Glial Fibrillary Acidic Protein Promoter Disrupts Neuronal Lamination by Dysregulating Neurogenesis during Embryonic Development

Abstract

<b><i>Introduction:</i></b> Transcription factor EB (TFEB), a key regulator of autophagy and lysosomal biogenesis, has diverse roles in various physiological processes. Enhancing lysosomal function by TFEB activation has recently been implicated in restoring neural stem cell (NSC) function. Overexpression of TFEB can inhibit the cell cycle of newborn cortical NSCs. It has also been found that TFEB regulates the pluripotency transcriptional network in mouse embryonic stem cells independent of autophagy and lysosomal biogenesis. This study aims to explore the effects of TFEB activation on neurogenesis in vivo through transgenic mice. <b><i>Methods:</i></b> We developed a glial fibrillary acidic protein (GFAP)-driven TFEB overexpression mouse model (TFEB GoE) by crossing the floxed TFEB overexpression mice and hGFAP-Cre mice. We performed immunohistochemical and fluorescence staining on brain tissue from newborn mice to assess neurogenesis changes, employing markers such as GFAP, Nestin, Ki67, doublecortin (DCX), Tbr1, and NeuN to trace different stages of neural development and cell proliferation. <b><i>Results:</i></b> TFEB GoE mice exhibited premature mortality, dying 10–20 days after birth. Immunohistochemical analysis revealed significant abnormalities, including disrupted hippocampal structure and cortical layering. Compared to control mice, TFEB GoE mice showed a marked increase in radial glial cells (RGCs) in the hippocampus and cortex, with Ki67 staining indicating these cells were predominantly in a quiescent state. This suggests that TFEB overexpression suppresses RGC proliferation. Additionally, abnormal distributions of migrating neurons and mature neurons were observed, highlighted by DCX, Tbr1, and NeuN staining, indicating a disruption in normal neurogenesis. <b><i>Conclusion:</i></b> This study, using transgenic animals in vivo, revealed that GFAP-driven TFEB overexpression leads to abnormal neural layering in the hippocampus and cortex by dysregulating neurogenesis. Our study is the first to discover the detrimental impact of TFEB overexpression on neurogenesis during embryonic development, which has important reference significance for future TFEB overexpression interventions in NSCs for treatment.