Figure 6. Piezo1 senses matrix stiffness and is involved in increased matrix stiffness–induced profibrotic responses in HK2 cells and mouse proximal tubular cells.

(A and B) Cell proliferation of HK2 cells cultured on polyacrylamide hydrogels with different stiffness, assessed by EdU. Scale bar: 500 μm. Data are shown as mean ± SEM (n = 4 in 4 kPa group, n = 5 in 8 kPa group, n = 8 in 20 kPa group, n = 9 in 35 kPa group). (C) Piezo1 mRNA level of HK2 cells cultured on polyacrylamide hydrogels with different stiffness. Data are shown as mean ± SEM (n = 4 in each group). (D and E) Representative immunoblots and corresponding densitometry analysis of Piezo1, fibronectin, and α-SMA protein abundance in HK2 cells cultured on polyacrylamide hydrogels with different stiffness. Data are shown as mean ± SEM (n = 4 in each group). (F and G) Representative immunoblots and corresponding densitometry analysis of fibronectin and α-SMA protein abundance in HK2 cells cultured on 4 kPa and 20 kPa polyacrylamide hydrogels, followed by treatment with GsMTx4. Data are shown as mean ± SEM (n = 4 in each group). *P < 0.05 when compared with 4 kPa and ^#P < 0.05 when compared with 20 kPa by 1-way ANOVA with Student-Newman-Keuls test. (H and I) Representative immunoblots and corresponding densitometry analysis of Piezo1, fibronectin, and α-SMA protein abundance in primary mPTCs cultured on polyacrylamide hydrogels with different stiffness. Data are shown as mean ± SEM (n = 4 in each group). (J and K) Representative immunoblots and corresponding densitometry analysis of fibronectin and α-SMA protein abundance in primary mPTCs cultured on polyacrylamide hydrogels with 4 kPa and 35 kPa stiffness, followed by treatment with GsMTx4. Data are shown as mean ± SEM (n = 4 in each group). *P < 0.05 when compared with 4 kPa and ^#P < 0.05 when compared with 35 kPa by 1-way ANOVA with Student-Newman-Keuls test. mPTCs, mouse proximal tubular cells; EdU, 5-ethynyl-2′-deoxyuridine.