Chen Sha, Schumacher Cees A, Van Amersfoorth Shirley C M, Fiolet Jan W T, Baartscheer Antonius, Veldkamp Marieke W, Coronel Ruben, Zuurbier Coert J
Amsterdam UMC, Location AMC, Department of Anaesthesiology, Laboratory of Experimental Intensive Care and Anaesthesiology (L.E.I.C.A.), Amsterdam, Netherlands.
Amsterdam Cardiovascular Sciences, Atherosclerosis & Ischemic Syndromes, Amsterdam, Netherlands.
Front Physiol. 2023 Jul 26;14:1179131. doi: 10.3389/fphys.2023.1179131. eCollection 2023.
SGLT2i directly inhibit the cardiac sodium-hydrogen exchanger-1 (NHE1) in isolated ventricular cardiomyocytes (CMs). However, other studies with SGLT2i have yielded conflicting results. This may be explained by methodological factors including cell isolation techniques, cell types and ambient pH. In this study, we tested whether the use of protease XIV (PXIV) may abrogate inhibition of SGLT2i on cardiac NHE1 activity in isolated rabbit CMs or rat cardiomyoblast cells (H9c2), in a pH dependent manner. Rabbit ventricular CMs were enzymatically isolated from Langendorff-perfused hearts during a 30-min perfusion period followed by a 25-min after-dissociation period, using a collagenase mixture without or with a low dose PXIV (0.009 mg/mL) present for different periods. Empagliflozin (EMPA) inhibition on NHE activity was then assessed at pH of 7.0, 7.2 and 7.4. In addition, effects of 10 min PXIV treatment were also evaluated in H9c2 cells for EMPA and cariporide NHE inhibition. EMPA reduced NHE activity in rabbit CMs that were not exposed to PXIV treatment or undergoing a 35-min PXIV treatment, independent of pH levels. However, when exposure time to PXIV was extended to 55 min, NHE inhibition by Empa was completely abolished at all three pH levels. In H9c2 cells, NHE inhibition by EMPA was evident in non-treated cells but lost after 10-min incubation with PXIV. NHE inhibition by cariporide was unaffected by PXIV. The use of protease XIV in cardiac cell isolation procedures obliterates the inhibitory effects of SGLT2i on NHE1 activity in isolated cardiac cells, independent of pH.
钠-葡萄糖协同转运蛋白2抑制剂（SGLT2i）可直接抑制离体心室心肌细胞（CMs）中的心脏钠氢交换体1（NHE1）。然而，其他关于SGLT2i的研究得出了相互矛盾的结果。这可能是由包括细胞分离技术、细胞类型和环境pH值在内的方法学因素所解释的。在本研究中，我们测试了使用蛋白酶XIV（PXIV）是否可以消除SGLT2i对离体兔CMs或大鼠心肌母细胞（H9c2）中心脏NHE1活性的抑制作用，且这种作用是否依赖于pH值。兔心室CMs通过酶解法从Langendorff灌注心脏中分离得到，在30分钟的灌注期后接着是25分钟的解离后期，使用不含或含有低剂量PXIV（0.009mg/mL）的胶原酶混合物，且PXIV在不同时间段存在。然后在pH值为7.0、7.2和7.4时评估恩格列净（EMPA）对NHE活性的抑制作用。此外，还在H9c2细胞中评估了10分钟PXIV处理对EMPA和卡立泊来德抑制NHE的影响。EMPA降低了未接受PXIV处理或接受35分钟PXIV处理的兔CMs中的NHE活性，且与pH水平无关。然而，当PXIV的暴露时间延长至55分钟时，在所有三个pH水平下，恩格列净对NHE的抑制作用均完全消除。在H9c2细胞中，EMPA对NHE的抑制作用在未处理的细胞中很明显，但在与PXIV孵育10分钟后消失。卡立泊来德对NHE的抑制作用不受PXIV影响。在心脏细胞分离过程中使用蛋白酶XIV可消除SGLT2i对离体心脏细胞中NHE1活性的抑制作用，且与pH无关。
