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Aim To observe whether the mechanosensitive ion channel Piezo1 was involved in the senescence of atrial fibroblasts by activating β-catenin based on our previous study which found marked increase of Piezo1 mRNA in senescent atrial fibroblasts. Methods Primary mouse atrial fibroblasts (MAFs) were isolated from male C57BL/6 mice (3-4 weeks) by enzyme digestion, and tert-butyl hydroperoxide (TBHP) was used to induce the senescence of cells. The ratio of senescent cells was detected by senescence-associated β-galactosidase (SA-β-Gal) staining. The protein levels of Piezo1, β-catenin/p-β-catenin, senescence-associated proteins p53 and p21 in the cells treated with TBHP (100 μmol · L
RESUMEN
Aim To investigate the role of mechano- sensitive ion channel Piezol in regulating electrical re-modeling of atrial myocytes induced by hypertension and to further explore the potential mechanisms.Methods Spontaneously hypertensive rats ( SHR ) aged 30 - 32 weeks treated with or without valsartan (30 mg • kg 1 • d 1 ) were used.Wistar rats were used as control.Western blot was used to detect the protein expression of Piezol , Src and Cavl.2 in atrial appendages of rats and in atrial myocytes ( HL-1 cells) exposed to different levels of high hydrostatic pressure (20 and 40 mmHg) , Piezol inhibitor (GsmTx4) and agonist ( Yodal ) in vitro.Whole-cell patch clamp technique was employed to detect L-tvpe calcium current (ICa, ) and action potential duration ( APD) of atrial myocytes.Results Compared with Wistar rats in control group, the protein expressions of Piezol and Src significantly increased and the expression of Cavl.2 decreased in SHR group (P < 0.05 ), while the a- bove changes could he reversed in SHR treated with valsartan( P < 0.05 ) .Meanwhile, higher hydrostatic pressure (40 mniHg) could increase the expressions of Piezol and Src in HL-1 cells( P <0.05) and decrease the protein expression of Cavl.2 (P <0.05 ) , accompanied by a shortened APD and a decreased ICa,.GsmTx4 could significantly reverse the above changes.In addition, Piezol agonist Yodal could simulate electrical remodeling and related signal molecule changes in atrial myocytes induced by the high hydrostatic pressure.Conclusions Mechanosensitive ion channel Piezol participates in electrical remodeling induced by hypertension via activating Src kinase signaling pathway and then leading to the decrease of ICa ,.