Figure 2. Mechanical signals cause rapid and transient βcatenin association with nucleoskeleton.

a) Schematic of nuclear envelope and nucleoskeleton connected to the F-actin cytoskeleton via LINC complexes (Nesprin-2 and Sun-1&2). At basal state, βcatenin can be found in both cytoplasm, nuclear envelope and nuclear fractions. We isolated the insoluble nucleoskeletal fraction (Nsk) enriched with Nuclear envelope proteins, LaminA/C and Nucleoporins to probe possible interactions of βcatenin with nucleoskeletal and nuclear envelope scaffold. b) MSCs were subjected to a single LIV bout (0.7g, 90Hz, 20min) and samples were collected immediately (20min) or 120min after. A third group was subjected to an initial LIV bout was subjected to a second LIV bout for 20min and collected immediately after LIV (160min total). Immediately after first LIV bout, βcatenin-Nsk association was increased to 178% (p<0.05, n=3) which returned to baseline after 120min (82%, NS, n=3). A second LIV bout elevated βcatenin-Nsk association to 176% (p<0.05, n=3) of non-LIV control. c) MSCs were subjected to a single strain bout (2%, 0.17Hz, 20min) and samples were collected immediately (20min) or 120min after. A third group was subjected to initial strain bout was subjected to a second strain bout for 20min and collected immediately after strain (160min total). Immediately after first strain bout, βcatenin-Nsk association was increased to 189% (p<0.05, n=3) which returned to baseline 120min after (73%, NS). A second strain bout elevated βcatenin-Nsk association to 200% of non-strain control. Group comparisons were made using One-way ANOVA followed by a Newman-Keuls post-hoc test (Fig.2b-c). (p<0.05, n=3). * p<0.05, ** p<0.01, *** p<0.001, against control and each other.