Temporal Transcriptional Regulation of Human Neuronal Differentiation via Forward Programming

Area of Science:

• Developmental Biology
• Stem Cell Biology
• Neuroscience

Background:

• Human pluripotent stem cells (hPSCs) are vital for studying human neurogenesis.
• Precise temporal control over hPSC differentiation into neurons is poorly understood.
• Comparing different differentiation systems is crucial for understanding timing mechanisms.

Purpose of the Study:

• To compare temporal control in transcription factor (TF)-induced forward programming versus dual-SMAD (DS) inhibition for hPSC neurogenesis.
• To identify gene regulatory networks (GRNs) governing differentiation timing and cell fate.
• To explore how modulating GRNs affects neurogenesis and neuronal maturation timing.

Main Methods:

• Comparative analysis of two distinct hPSC differentiation systems (TF-induced vs. DS inhibition).
• Multi-omic analysis to identify key gene regulatory networks (GRNs).
• Perturbation of identified GRNs to assess impact on neurogenesis timing.

Main Results:

• Divergent cellular trajectories in the two systems lead to distinct neurogenesis timing.
• Identified GRNs critically control cell fate determination and differentiation timing.
• OLIG family TFs promote cell cycle exit via NOTCH signaling, influencing neurogenesis timing.
• NEUROD2 overexpression accelerates neuronal maturation in both differentiation systems.

Conclusions:

• Elucidated transcriptional mechanisms underlying differentiation timing in hPSCs.
• Demonstrated that GRNs and specific transcription factors (e.g., OLIGs, NEUROD2) modulate neurogenesis and maturation timing.
• Provides a framework for rationally designing timing-controlled in vitro neuronal differentiation strategies.