Fig. 7: CAPN2-STAT3 Axis Regulates IL-33 Expression Upon PIEZO1 Activation.

HUVECs under 20% stretch for 0,6,24 h or 2,12,25 kPa substrates; IL-33 secretion (n = 3) A and mRNA (n = 3) B. C PIEZO1 knock-down with shPIEZO1 (n = 3). HUVECs were transduced with shPIEZO1 for 48 h, cultured on 25 kPa substrates for 24 h or subjected to 6 h mechanical stretch before measuring IL-33 secretion (n = 3) D and mRNA (n = 3) E. HUVECs were cultured on 2, 12, 25 kPa substrates for 24 h or stretched (20%) for 0, 6, 24 h, followed by measurement of calpain activity F and CAPN2 protein G (n = 3). HUVECs (shPIEZO1) were cultured on 25 kPa substrates for 24 h or subjected to 6 h mechanical stretch, followed by measurement of calpain activity (n = 3) H and CAPN2 protein levels (n = 3) I. J CAPN2 knock-down with shCAPN2 (n = 3). K HUVECs (shCAPN2) were cultured on 25 kPa substrates for 24 h or subjected to 6 h mechanical stretch, IL-33 secretion(left) and mRNA(right) (n = 3). L Model for paracrine IL-33 regulation. M Cistrome: STAT3 predicted to drive IL-33 regulation. N intersection of top 100 motifs in BLM-treated mouse ECs with top 10 TFs. O The protein levels of P-STAT3 and STAT3 in HUVECs treated with 20% stretch for 0 and 6 hours (n = 3). P The protein levels of P-STAT3 and STAT3 in HUVECs (shPIEZO1 or shCAPN2) treated with 20% stretch for 6 h (n = 3). Q STAT3 knock-down with shSTAT3 (n = 3). R HUVECs (shSTAT3) were cultured on 25 kPa substrates for 24 h or subjected to 6 h mechanical stretch; IL-33 secretion(left) and mRNA(right) (n = 3). Error bars: mean ± SEM; C, G, J, O–Q: two-tailed unpaired t-test; A, B, F: one-way ANOVA followed Šídák’s multiple comparisons test, D–E, H–I, K, R: two-way ANOVA Tukey’s multiple comparisons test. All n denote biologically independent samples. Source data are provided as a Source Data file.