A soft-stiff patterned bioengineering model reveals kinase pathways driving directional cell migration in pulmonary arterial hypertension.

Directional cell migration by pulmonary arterial cells (PACs) is one of the important features of diseases involving arterial remodeling, such as pulmonary arterial hypertension (PAH), a disease that is often characterized by reduced arterial compliance and increased extracellular matrix (ECM) stiffening. However, there are no therapeutics that can halt the directional cell migration of PACs in PAH. The inability to identify drug targets or drugs against the directional cell migration during PAH pathogenesis stems from an incomplete understanding of the process and a lack of effective translational models for screening of candidate small molecules. Here, for the first time, we introduce a bioengineered platform suitable for screening small molecule inhibitors targeting kinase pathways that are potentially linked to ECM-mediated directed cell migration in PAH. We used a photolithographic technique to develop mechanically patterned hydrogels with alternative stripes of soft and stiff bars representing the alternating stiffness regions of PAH ECM. Employing our bioengineered platform, we demonstrated the directional cell migration capacity of PACs and found that PAH-smooth muscle cells (SMCs) showed the highest ability to migrate from soft-stiff regions. Screening of different kinase inhibitors identified the role of JAK/STAT as a mechanosensor in the PAH-SMC-specific directional cell migration. Our study highlighted the use of a mechanically patterned bioengineering platform to identify new drug targets specific to the machinery involved in directional cell migration in PAH.