Victoria Milosek, Lei Mei, Aaron Baker
Vascular endothelial cells (ECs) serve as a barrier between blood and tissues as well as control the degree of vascular relaxation and constriction. ECs are continually exposed to mechanical forces like circulation, blood pressure, and shear stress, which plays a critical role in regulating ECs function. Syndecan-1 (SDC1) is a transmembrane cell surface proteoglycan that is known to play a role in flow sensation in arteries as well as to control the inflammatory phenotype of ECs. However, it has yet to be determined if SDC1 is a mechanosensory that responds to blood flow and transmits the physical cues to downstream pathways. In this study, HUVECs were transduced with 3xHA-SDC1. The cells then underwent shear stress at 12 dynes/cm 2 for a duration of 15 minutes. A co-immunoprecipitation assay was performed to pull down a set of proteins that are known to bind to SDC1. Subsequent Western blots showed that shear stress induced SDC1 binding to β-actin and Src. Immunostaining for SDC1 as well as β-actin and Src after shear stress also indicated the increased co-localization. These results suggest that shear stress leads to rapid linking of SDC1 in the cytoskeleton and triggers a possible pathway beginning with the Src family. These findings support that SDC1 may serve as a mechanosensor when endothelial cells experience shear stress, promoting its binding to actin and related signaling pathways compared to static conditions.
Comments
Great job! From a design standpoint, I’m a big fan of how you did things like Figure 2c — very clear visual explanation of one of the processes that you followed. —Rob Reichle