Multiplex microfluidic perfusion identifies shear stress mechanosensing mediators in mouse embryonic stem cells

Shear stress is a ubiquitous but obscure environmental cue in perfusion stem cell cultures, especially under self-renewing (pluripotency maintenance) conditions. We used a multiplex microfluidic array, which overcomes limitations in shear application throughput and precision faced by macro-perfusion systems, to comprehensively study shear effects on self-renewing mouse embryonic stem cells. When compared to static cultures with or without a saturated soluble environment, shear stress specifically upregulates the epiblast maker, Fgf5. Further targeting of related molecular elements revealed that heparan sulfate proteoglycans are involved in shear mechanosensing. This study demonstrates microfluidics' utility in parsing flow-dependent factors within the stem cell niche