Matrix stiffness regulates SMC functions via TGF-β signaling pathway.

Area of Science:

• Biomedical Engineering
• Mechanobiology
• Vascular Biology

Background:

• Vessel wall stiffness changes are implicated in numerous blood vessel pathologies.
• The precise mechanisms by which stiffness influences vascular cell phenotype remain unclear.

Purpose of the Study:

• To investigate the effects of varying matrix stiffness on the phenotype and function of vascular smooth muscle cells (SMCs).
• To elucidate the role of the TGF-β signaling pathway in mediating stiffness-induced changes in SMCs.

Main Methods:

• Culturing SMCs on matrices with stiffness ranging from 1 to 100 kPa.
• Analyzing the expression of contractile (CNN1, SMTN) and synthetic (OPN, EREG) markers.
• Assessing matrix metalloproteinase 2 (MMP-2) expression.
• Examining Smad2/3 phosphorylation and the impact of TGF-β pathway inhibition.

Main Results:

• Contractile marker expression increased with stiffness, while synthetic marker expression was highest on soft matrices (1 kPa).
• MMP-2 was upregulated on the 1-kPa surface.
• Atherosclerotic lesions showed decreased stiffness, reduced CNN1 and collagen, and increased OPN and MMP-2.
• Smad2/3 phosphorylation correlated with matrix stiffness, and TGF-β inhibition reversed stiffness effects.

Conclusions:

• Matrix stiffness regulates SMC phenotype and matrix remodeling, primarily through the TGF-β signaling pathway.
• This study provides a mechanobiological understanding of vascular remodeling.
• Findings can inform strategies for vascular tissue engineering, disease modeling, and therapeutic development.