Update: Generating a 3D spatially patterned FSHD tissue construct for disease modeling and therapeutic strategies using suspended tissue open microfluidic patterning (STOMP)

Report by Lauren G Brown
See also Generating a 3D spatially patterned FSHD tissue construct for disease modeling and therapeutic strategies using suspended tissue open microfluidic patterning (STOMP)

My project aims to develop physiologically relevant tissue models in the lab for FSHD using STOMP (Suspended Tissue Open Microfluidic Patterning), a 3D-printed microfluidic-based tissue patterning technique developed by my lab. This project seeks to develop FSHD models that can be used to track functional outcomes and biochemical interactions of FSHD-diseased muscle tissue with adjacent healthy muscle tissue.

Thus far, I have successfully demonstrated STOMP’s ability to create a single tissue containing a border region between healthy and diseased tissue. I have also established 3D cultures of MB135 (healthy) and MB200 (FSHD) cells, which have not previously been cultured in 3D. With the FSHD models, I observed baseline DUX4 expression and found enhanced DUX4 and target gene expression in 3D compared to 2D after 1 week in culture. I also have been able to track drug response with losmapimod and clenbuterol over the course of 10 days in culture.

However, in my current 3D models, I have observed limited fusion between healthy and diseased cells at the border region. Additionally, my preliminary work found that drug effectiveness was reduced in 3D cultures compared to 2D cultures, which could be due to limited myotube formation and fusion I observe in the 3D cultures. To address these limitations, I plan to switch to human induced pluripotent stem cells (hiPSCs) that were taken from FSHD mosaic patients. Myogenic progenitors from hiPSCs have previously been shown in the literature to exhibit better differentiation in 3D. With this new cell type, I plan to further study DUX4 signaling between healthy and diseased nuclei at the border region as well as investigate inflammation and immune components in the model in response to drug treatment.