Regulation of NTRK2 alternative splicing by PRPF40B controls neural differentiation and synaptic plasticity

BDNF signaling through its receptor TRKB plays a critical role in brain development, neuroplasticity, and homeostasis. Alternative splicing of the TRKB gene, NTRK2, generates either the full-length receptor (TRKB-FL) or a truncated isoform (TRKB-T1) that inhibits BDNF signaling and has been implicated in neurodegenerative diseases, psychiatric disorders, and cognitive impairments. Here, we show that PRPF40B, a splicing factor associated with neuronal dysfunction, promotes the production of the TRKB-FL isoform during neuronal differentiation. Silencing PRPF40B increases TRKB-T1 expression and impairs the expression of genes important for neuronal differentiation and synaptic plasticity, both in vitro and in vivo, during early embryogenesis. Our data thus identify PRPF40B as a key regulator of the balance between TRKB receptor isoforms, crucial for fine-tuning neuronal responses and for preventing neuroplasticity or survival impairments, providing also a mechanism for the role of PRPF40B in the pathogenesis of various human neurodegenerative diseases and psychiatric disorders.