Effects Of Na⁺/H⁺ Exchanger-1 And Its Blocker On The Proliferation, Collagen Secretion And The Ca²⁺ Regulation In Cardiac Fibroblasts Induced By High-salt

Objective:To investigate the effect of Na⁺-H⁺exchanger-1 and its blockeron proliferation,collagen secretion and Ca²⁺regulation in cardiac fibroblasts?CFs?induced by high-salt.Methods:Hearts of SD neonatal rat were isolated to culture CFs with tissue block method.The third generation cells was divided into NS group?Na⁺139mmol/L?and HS group?Na⁺161mmol/L?,intervented 48 hours.Then detect CFs proliferation and assay the effective concentration of Cariporide by MTT.The 3-4 generation CFs were synchronized with free-serum medium for 24h,then divided into 3 group:NS group?Na⁺139mmol/L?,HS group?Na⁺161mmol/L?,HS+Criporide group?Na⁺159mmol/L+Cariporide 30?M?,then continued to culture for 48h.Methode of EdU was applied to detect cells proliferation,The content of collagenI?COL1?,collagenIII?COL3?in CFs culture liquid was detected by means of ELISA;Ca²⁺-ATPase and Na⁺/K⁺-ATPase activity was detected by Enzymatic colorimetry;Western Blot assay were performed to detect the protein level of NHE-1,NCX-1.The fluorescence ratio assay was employed to detect intracellular pH and Ca²⁺concentration in CFs.Results:MTT assay showed that the Cariporide started to inhibit CFs proliferatation in concentration of 10?mol/L.,Compared with the control group,the CFs proliferate significant;the content of COL1,COL3 was increased?P<0.05?;the activity of Ca²⁺-ATPase and Na⁺/K⁺-ATPase activity decreased?P<0.05?;protein expression of COL1,COL3,NHE-1 and NCX-1 was increased?P<0.05?;and the intracellular free Ca²⁺concentration and pH distinctly increased?P<0.05?.After intervening with Cariporide,the CFs proliferation was inhibited?P<0.05?;the activity of Ca²⁺-ATPase and Na⁺/K⁺-ATPase activity was increased;the content of COL1,COL3 and the protein expression of COL1,COL3,NHE-1,NCX-1 was lowered?P<0.05?,the intracellular free Ca²⁺and pH were distinctly decreased?P<0.05?.Conclusion:?.NHE-1 inhibitor Cariporide can inhibit CFs proliferation and COL1,COL3 seretion induced by high sodium.?.High sodium can lead to intracellular free Ca²⁺and pH increasing,and Cariporide attenuated the process.?.NHE-1 inhibitor Cariporide can reverse CFs Ca²⁺ATPase and Na⁺/K⁺-ATPase activity decrease,lower the content increase of COL1,COL3,and down-regulate the high expression of COL1,COL3,NHE-1and NCX-1 protein induced by high sodium to regulate the intracellular free Ca²⁺ concentrate.