Depolymerizing F-actin accelerates the exit from pluripotency to enhance stem cell-derived islet differentiation

Area of Science:

• Stem cell biology
• Developmental biology
• Cell signaling

Background:

• The cytoskeletal state influences cell fate decisions.
• Human pluripotent stem cells (hPSCs) require precise differentiation protocols for therapeutic applications.
• Early signaling events are critical for lineage specification.

Purpose of the Study:

• To investigate the impact of cytoskeletal state on hPSC differentiation.
• To determine if modulating F-actin dynamics can improve pancreatic progenitor generation.
• To enhance the efficiency and consistency of generating functional pancreatic islets from hPSCs.

Main Methods:

• Depolymerization of F-actin using latrunculin A (latA) during the initial 24 hours of definitive endoderm formation.
• Analysis of pluripotency exit and lineage specification.
• Assessment of signaling pathway dynamics (Activin/Nodal, BMP, c-Jun, WNT).
• Evaluation of downstream gut tube patterning and pancreatic progenitor identity.
• Characterization of pancreatic islet cell composition, maturation, and function (insulin secretion, glucose-lowering capacity).

Main Results:

• LatA treatment during early differentiation facilitated efficient loss of pluripotency.
• Modulation of F-actin altered key signaling pathway dynamics.
• Improved pancreatic progenitor identity and reduced markers of other endodermal lineages were observed.
• Generated islets showed increased beta cell percentage, enhanced maturation, and improved insulin secretion.
• LatA treatment corrected differentiation failures in certain hPSC lines and reduced enterochromaffin cell populations.

Conclusions:

• Cytoskeletal state at the onset of differentiation is crucial for hPSC lineage specification.
• Targeting F-actin dynamics provides a strategy to enhance pancreatic progenitor differentiation and beta cell function.
• This approach improves the consistency and efficiency of generating pancreatic islets for potential therapeutic use.