TGFβ-TAZ/SRF signalling regulates vascular smooth muscle cell differentiation

Area of Science:

• Vascular biology
• Cell signaling
• Molecular mechanisms

Background:

• Vascular smooth muscle cells (VSMCs) exhibit phenotypic plasticity, contributing to vascular diseases.
• Transforming growth factor beta (TGFβ) signaling is implicated in VSMC differentiation, but mechanisms are unclear.
• The transcriptional regulator TAZ's role in VSMC differentiation requires elucidation.

Purpose of the Study:

• To investigate the transcription factor network in VSMC differentiation.
• To determine the specific role of TAZ in promoting the quiescent VSMC phenotype.
• To elucidate the signaling pathway linking TGFβ to VSMC differentiation.

Main Methods:

• Utilized primary aortic VSMCs.
• Employed siRNA-mediated gene silencing to assess TAZ function.
• Analyzed synergy between TAZ, SRF, and Myocardin (MyoC856) in gene regulation.
• Investigated physical interaction between TAZ and MyoC856.

Main Results:

• TAZ is indispensable for TGFβ-induced smooth muscle gene expression.
• TAZ is required for maintaining the differentiated VSMC phenotype.
• Synergistic regulation of smooth muscle gene activation by TAZ with SRF and MyoC856 was observed.
• A physical interaction between TAZ and MyoC856 was identified.

Conclusions:

• TAZ acts as a crucial mediator in TGFβ-induced VSMC differentiation.
• A novel signaling pathway involving TAZ, SRF, and MyoC856 regulates VSMC phenotype.
• These findings offer insights into vascular diseases and congenital vascular malformations.