A Bivalent Securinine Compound SN3-L6 Induces Neuronal Differentiation via Translational Upregulation of Neurogenic Transcription Factors

Abstract

Developing therapeutic approaches that target neuronal differentiation will be greatly beneficial for the regeneration of neurons and synaptic networks in neurological diseases. Protein synthesis (mRNA translation) has recently been shown to regulate neurogenesis of neural stem/progenitor cells (NSPCs). However, it has remained unknown whether engineering translational machinery is a valid approach for manipulating neuronal differentiation. The present study identifies that a bivalent securinine compound SN3-L6, previously designed and synthesized by our group, induces potent neuronal differentiation through a novel translation-dependent mechanism. An isobaric tag for relative and absolute quantitation (iTRAQ)-based proteomic analysis in Neuro-2a progenitor cells revealed that SN3-L6 upregulated a group of neurogenic transcription regulators, and also upregulated proteins involved in RNA processing, translation, and protein metabolism. Notably, puromycylation and metabolic labeling of newly synthesized proteins demonstrated that SN3-L6 induced rapid and robust activation of general mRNA translation. Importantly, mRNAs of the proneural transcription factors Foxp1, Foxp4, Hsf1, and Erf were among the targets that were translationally upregulated by SN3-L6. Either inhibition of translation or knockdown of these transcription factors blocked SN3-L6 activity. We finally confirmed that protein synthesis of a same set of transcription factors was upregulated in primary cortical NPCs. These findings together identify a new compound for translational activation and neuronal differentiation, and provide compelling evidence that reprogramming transcriptional regulation network at translational levels is a promising strategy for engineering NSPCs.

Autism-like social deficit generated by Dock4 deficiency is rescued by restoration of Rac1 activity and NMDA receptor function

“…To measure protein synthesis, we used puromycin, an aminonucleoside antibiotic structurally similar to aminoacyl-tRNAs, to label newly synthesized polypeptides 41 , 42 . Notably, global protein synthesis was significantly lower in hippocampal neurons cultured from Dock4 KO mice than WT littermates, as indicated by diminished labeling of puromycin ( Figure 5c,d ).…”

Predicting Epigenomic Functions of Genetic Variants in the Context of Neurodevelopment via Deep Transfer Learning

“…We detected many iPSC-specific motifs such as CTCF, an important regulator for chromatin structure [53], and POU5F1B(OCT4-PG1), a key player in the stem cell induction process [73]. In dopaminergic (DN) cell, we found motifs of proneural transcription factor FOXP4 that plays an important role in neural development [44] and FOXO6, a transcription factor closely related to cortical development [54,72]. We discovered OLIG2, a transcription factor associated with cortical neurogenesis [45] and EN2 a transcription factor links to many stages of neural devlopment [25] in samples from the human neocortex(GZ, CP) [16].…”

Two Autism/Dyslexia Linked Variations of DOCK4 Disrupt the Gene Function on Rac1/Rap1 Activation, Neurite Outgrowth, and Synapse Development

“…Transfection of plasmids was using Lipofectamine LTX (Invitrogen). To study neurite outgrowth, the culture medium of Neuro-2a cells was switched into differentiation medium (MEM supplemented with 0.5% FBS) in the presence of 15 µM RA for 48 h (Xiao et al, 2013;Liao et al, 2018). Primary cultures of rat hippocampal neurons were prepared from E18 Sprague Dawley rat embryos as described previously (Xiao et al, 2013;Tang et al, 2015).…”