The Effects of Stretch on Intracellular Ca2+ Signaling in Cocultured Neuronal and Smooth Muscle Cells

Skinner, Connor J.

Student Work

The Effects of Stretch on Intracellular Ca2+ Signaling in Cocultured Neuronal and Smooth Muscle Cells

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The purpose of this project is to better understand how differentiated smooth muscle (WKO-3M22) and neuronal cells (PC12) vary their calcium signaling response with regards to repeated physical stress, and how the formation of neuromuscular junctions (NMJs) between the two cell types affects this response. Ca2+ signaling in cells is largely mediated by the protein Gαq and can affect everything from a cell’s life cycle to electrical signaling and muscle contractions. In this study, mechanical stretch increased the cells’ calcium signaling responses when placed under hyperosmotic stress by the addition of salt. This increase was much larger in the cocultured cells and in isolated PC12 cells as compared to isolated WKO cells. Additionally, when the two cell types were cocultured and neuromuscular junctions formed, there was a noticeable increase in neurite formation and branching in the cells, and the two cell types converged upon a similar calcium response. Furthermore, a small population of the cocultured cells did not respond to the salt stimulation with either a calcium response or the morphological “shriveling” characteristic of the hyperosmotic stress. This suggests that the formation of the neuromuscular junctions may enhance resistance to stress and deformation in the two cell types. Understanding the role of these neuromuscular junctions in maintaining cellular health and disease prevention is crucial for growing mature muscle tissue in vitro, advancing our knowledge of how diseases caused by impaired NMJs function, such as Myasthenia Gravis and Lambert-Eaton Myasthenic Syndrome, and opening the door to future research into the various ways NMJs enhance the health of their component cells.

This report represents the work of one or more WPI undergraduate students submitted to the faculty as evidence of completion of a degree requirement. WPI routinely publishes these reports on its website without editorial or peer review.

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