Biomimetic Topological Micropattern Arrays Regulate the Heterogeneity of Cellular Fates in Lung Fibroblasts between Fibrosis and Invasion

Idiopathic pulmonary fibrosis (IPF) is characterized
by persistent
tissue injury, dysregulated wound healing, and extracellular matrix
(ECM) deposition by myofibroblasts (MFs) through the fibroblast-to-myofibroblast
transition (FMT). Implicit in the FMT process are changes in the ECM
and cellular topology, but their relationship with the lung fibroblast
phenotype has not been explored. We engineered topological mimetics
of alignment cues (anisotropy/isotropy) using lung decellularized
ECM micropattern arrays and investigated the effects of cellular topology
on cellular fates in MRC-5 lung fibroblasts. We found that isotropic
MRC-5 cells presented changes of the cytoskeleton, increased cell–cell
adhesions and a multicellular architecture with increased overlap,
changes in actin–myosin development, and enhanced focal adhesion
and cell junction with random alignment. Besides, anisotropic fibroblasts
were activated into a regular phenotype with an ECM remodeling profile.
In contrast, isotropic fibroblasts developed a highly invasive phenotype
expressing molecules, including CD274/programmed death-ligand 1 (PD-L1),
cellular communication network factor 2 (CCN2)/connective tissue growth
factor (CTGF), hyaluronan synthase 2 (HAS2), and semaphorin 7A (SEMA7A),
but with downregulated matrix genes. Moreover, isotropic fibroblasts
also showed higher expressions of Ki-67 and cyclin D1 (CCND1), resistance
to apoptosis/senescence, and decreased autophagy. The topology regulated
the cellular heterogeneity and resulted in positive feedback between
changes in the cellular phenotype and the ECM structure, which may
aggravate fibrosis and lead to a priming of malignant microenvironment
during carcinogenesis. Using the versatile platform of micropattern
array, we can not only visualize the interaction mechanism between
cells and the ECM but also select potential clinical targets for diagnosis
and therapeutics.