Fig. 4. Borax effects on myosin light chain phosphorylation and actin stress fiber formation.
a Immunofluorescence images of actin cytoskeleton (green), nuclei (cyan), and pMLC (pMyosin, magenta) as markers of cellular tension and contractility. MSCs were cultured for 3 h onto functionalized substrates (FN-coated), with the presence of serum-depleted and borax (PLLA-B2%, PLLA-B5%) in the culture medium. The same experiment was performed after NaBC1 silencing using esiRNANC (negative control) and esiRNANaBC1. The PLLA-B2% and PLLA-B5% substrates presented higher levels of actin fibers and pMLC staining that strongly diminished after NaBC1 silencing (see inset magnifications). Scale bar 25 µm. b Image analysis quantification before and after NaBC1 silencing of pMLC staining, parameter related to cell contractility. Active NaBC1 induces cell contractility. Fifteen images/condition from three different biological replicas were analyzed. The data represented in graphs correspond to n ≥ 7. Statistics are shown as mean ± standard deviation. Data were analyzed by an ordinary one-way ANOVA test and corrected for multiple comparisons using Dunnett analysis (P = 0.05). *p < 0.05, **p < 0.01, ****p < 0.0001.