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- 2017
成年大鼠心室肌细胞表达多种电压门控钠通道α亚型
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Abstract:
摘要：目的 观察成年大鼠心室肌细胞上电压门控钠通道不同亚型的表达情况。方法 采用酶解消化法分离成年大鼠心室肌细胞，利用免疫荧光染色结合激光共聚焦技术检测心室肌细胞钠通道α亚型Nav1.1、Nav1.2、Nav1.3、Nav1.5、Nav1.6、Nav1.7的表达及分布情况，采用全细胞膜片钳技术记录心室肌细胞钠电流。结果 成年大鼠心室肌细胞除表达心脏型钠通道亚型Nav1.5之外，还表达神经型钠通道亚型Nav1.1、Nav1.6和Nav1.7，不表达Nav1.2和Nav1.3。Nav1.5分布于横小管周围，Nav1.1和Nav1.7亦呈点状分布于横小管区域。Nav1.6表达稍弱，沿心室肌细胞长轴纵向分布，闰盘处未见钠通道各α亚型的表达。膜片钳结果显示成年大鼠心室肌细胞表达快钠电流(INa,T)及晚钠电流(INa,L)。结论 成年大鼠心室肌细胞表达心脏型钠通道亚型(Nav1.5)和多种神经型钠通道亚型(Nav1.1、Nav1.6和Nav1.7)，这可能有助于维持心肌细胞的正常电生理活动。
ABSTRACT: Objective To observe the expressions of voltage-gated sodium channel (NaCh) α subunits in adult rat ventricular myocytes. Methods Single ventricular myocytes were isolated from adult rat heart. Expressions of various α subunits (Nav1.1, Nav1.2, Nav1.3, Nav1.5, Nav1.6 and Nav1.7) of NaCh in the ventricular myocytes were detected by immunocytochemistry staining. Sodium current was recorded by whole-cell patch clamp method. Results The neuronal subunits Nav1.1, Nav1.6 and Nav1.7 as well as the cardiac subunit Nav1.5 of NaCh were expressed in adult rat ventricular myocytes. Nav1.1, Nav1.5 and Nav1.7 were distributed along the cell membrane of the ventricular myocytes and around the transverse tubule; Nav1.6 was labeled along the cell membrane by lengthways. All these subunits were not colocalized with Cx43 at the intercalated disc. Both transient sodium current (INa,T) and late sodium current (INa,L) were recorded from adult rat ventricular myocytes. Conclusion Various neuronal subunits (Nav1.1, Nav1.6 and Nav1.7) as well as cardiac subunit (Nav1.5) of NaCh were expressed in adult rat ventricular myocytes, which is important for normal function of INa,T and INa,L
| [1] | ZHENG J, TRUDEAU MC. Handbook of ion channels[M]. 1st ed. Florida, USA: Taylor & Francis Group, 2015: 213-226. |
| [2] | 胡培静，杜媛，王娅，等. 钠通道SCN5a突变体R104W的构建及验证[J]. 西安交通大学学报(医学版), 2015, 36(4):435-438. |
| [3] | HUND TJ, MOHLER PJ. Nav channel complex heterogeneity: New targets for the treatment of arrhythmia?[J]. Circulation, 2014, 130(2):132-134. |
| [4] | DUCLOHIER H. Neuronal sodium channels in ventricular heart cells are localized near T-tubules openings[J]. Biochem Biophys Res Commun, 2005, 334(4):1135-1140. |
| [5] | MAIER SK, WESTENBROEK RE, SCHENKMAN KA, et al. An unexpected role for brain-type sodium channels in coupling of cell surface depolarization to contraction in the heart[J]. Proc Natl Acad Sci USA, 2002, 99(6):4073-4078. |
| [6] | NOUJAIM SF, KAUR K, MILSTEIN M, et al. A null mutation of the neuronal sodium channel NaV1.6 disrupts action potential propagation and excitation-contraction coupling in the mouse heart[J]. FASEB J, 2012, 26(1):63-72. |
| [7] | HAUFE V, CORDEIRO JM, ZIMMER T, et al. Contribution of neuronal sodium channels to the cardiac fast sodium current INa is greater in dog heart Purkinje fibers than in ventricles[J]. Cardiovasc Res, 2005, 65(1):117-127. |
| [8] | WESTENBROEK RE, BISCHOFF S, FU Y, et al. Localization of sodium channel subtypes in mouse ventricular myocytes using quantitative immunocytochemistry[J]. J Mol Cell Cardiol, 2013, 64:69-78. |
| [9] | MASUMIYA H. Contribution of Nav1.1 to cellular synchronization and automaticity in spontaneous beating cultured neonatal rat ventricular cells[J]. Gen Physiol Biophys, 2011, 30(1):28-33. |
| [10] | XI Y, WU G, YANG L, et al. Increased late sodium currents are related to transcription of neuronal isoforms in a pressure-overload model[J]. Eur J Heart Fail, 2009, 11(8):749-757. |
| [11] | VEERARAGHAVAN R, GY？ZRKE S, RADWANSKI PB. Neuronal sodium channels: Emerging components of the nano-machinery of cardiac calcium cycling[J]. J Physiol, 2017, 595(12):3823-3834. |
| [12] | DU Y, HUANG X, WANG T, et al. Downregulation of neuronal sodium channel subunits Nav1.1 and Nav1.6 in the sinoatrial node from volume-overloaded heart failure rat[J]. Pflugers Arch, 2007, 454(3):451-459. |
| [13] | LUO L, NING F, DU Y, et al. Calcium-dependent Nedd4-2 upregulation mediates degradation of the cardiac sodium channel Nav1.5: Implications for heart failure[J]. Acta Physiol (Oxf), 2017, 221(1):44-58. |
| [14] | MAIER SK, WESTENBROEK RE, MCCORMICK KA, et al. Distinct subcellular localization of different sodium channel alpha and beta subunits in single ventricular myocytes from mouse heart[J]. Circulation, 2004, 109(11):1421-1427. |
| [15] | CERBAI E, SARTIANI L, DE PAOLI P, et al. Isolated cardiac cells for electropharmacological studies[J]. Pharmacol Res, 2000, 42(1):1-8. |
| [16] | MISHRA S, REZNIKOV V, MALTSEV VA, et al. Contribution of sodium channel neuronal isoform Nav1.1 to late sodium current in ventricular myocytes from failing hearts[J]. J Physiol, 2015, 593(6):1409-1427. |
| [17] | DHAR MALHOTRA J, CHEN C, RIVOLTA I, et al. Characterization of sodium channel alpha- and beta-subunits in rat and mouse cardiac myocytes[J]. Circulation, 2001, 103(9):1303-1310. |
| [18] | RADWA？ZSKI PB, HO HT, VEERARAGHAVAN R, et al. Neuronal Na<sup>+</sup> channels are integral components of pro-arrhythmic Na<sup>+</sup>/Ca<sup>2+</sup> signaling nanodomain that promotes cardiac arrhythmias during β-adrenergic stimulation[J]. JACC Basic Transl Sci, 2016, 1(4):251-266. |
