The Role of Matrix Stiffness in Regulating SUN2 and P-Lamin A/C During TGFβ1-Induced Epithelial-Mesenchymal Transition
Open Access
- Author:
- Chen, Davon
- Area of Honors:
- Chemical Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Michael John Janik, Thesis Supervisor
Esther Gomez, Thesis Honors Advisor - Keywords:
- SUN2
Matrix Stiffness
P-Lamin A/C
Cell Contractility
TGFβ1
Epithelial-Mesenchymal Transition
Y27632 ROCK Inhibitor - Abstract:
- Epithelial-mesenchymal transition (EMT) is a process in which epithelial cells assume mesenchymal cell phenotype by losing their cell-cell adhesion and gaining migratory properties [6]. This process is involved in embryo formation, organ development, wound healing, tissue regeneration, and cancer progression [6]. Studies have shown that transforming growth beta 1 (TGFB1) induces EMT, leading to the decrease of E-cadherin expression and an increase in Snail, Slug, Twist, and Vimentin [8,9,37,38,45]. These nuclear envelope proteins and transcription factors have been shown to play a role in EMT, although the exact pathways are not clear for all proteins [8,9]. Previous studies have also consistently found softer matrices protect cells from EMT induction by TGFB1, but stiffer substrates tend to show higher levels of inner nuclear membrane protein expression, like lamin A/C, when treated with TGFB1 [32,33,62]. Matrix stiffness plays an important role in EMT as fibrosis and cancer have been linked to increased stiffness in the extracellular matrix (ECM) [32,33]. However, there are limited studies on SUN2, a different inner nuclear membrane protein, and the phosphorylation of lamin A/C (p-lamin A/C) during TGFB1-induced EMT. We aim to gain a deeper understanding of EMT pathways by studying SUN2 and Lamin A/C phosphorylation in TGFB1-induced EMT on normal mouse mammary gland (NMuMG) epithelial cells. Additionally, the impact of abrogating cell contractility will be studied by using the Y27632 ROCK inhibitor to block the RhoA/ROCK signaling pathway. We hypothesize that cells cultured on higher stiffness matrices will exhibit higher SUN2 expression and lower p-lamin A/C expression during TGFB1-induced EMT and that cells treated with the Y27632 ROCK inhibitor will demonstrate less cell contractility and EMT characteristics. Using immunofluorescence staining, the results showed a correlation between SUN2 and p-lamin A/C expression regulated by matrix stiffness and TGFB1, although they differ from related past research, and that inhibiting cell contractility decreased EMT characteristics in cells treated with or without TGFB1. This study will serve as part of the foundation for future research in SUN2 and p-lamin A/C expression during EMT.