Na,K-ATPase α4, and Not Na,K-ATPase α1, is the Main Contributor to Sperm Motility, But its High Ouabain Binding Affinity Site is Not Required for Male Fertility in Mice.
Na,K-ATPase α4, and Not Na,K-ATPase α1, is the Main Contributor to Sperm Motility, But its High Ouabain Binding Affinity Site is Not Required for Male Fertility in Mice.
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Na,K-ATPase α4（而不是 Na,K-ATPase α1）是精子活力的主要贡献者，但其高哇巴因结合亲和力位点并不是小鼠雄性生育能力所必需的。
DOI：
10.1007/s00232-021-00181-2
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Blanco,Gustavo
中科院分区：
文献类型：
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作者：
McDermott,JeffP;Sánchez,Gladis;Mitra,Amrita;Numata,September;Liu,LijunCatherine;Blanco,Gustavo
哺乳动物精子表达两种 Na,K-ATP 酶 (NKA) 亚型：Na,K-ATP 酶 α4 (NKAα4) 和 Na,K-ATP 酶 α1 (NKAα1)。虽然 NKAα4 对精子运动至关重要，但 NKAα1 在精子运动中的作用仍不清楚。我们在这里使用遗传和药理学方法确定了这一点，修改NKAα1和NKAα4与抑制剂哇巴因的亲和力，以选择性地阻断每种亚型的功能。使用来自野生型 (WT) 小鼠（天然含有乌巴因抗性 NKAα1 和哇巴因敏感 NKAα4）和三个新生成的小鼠品系的精子，这些小鼠品系同时表达 NKAα1 和 NKAα4 乌巴因抗性 (OR)、哇巴因敏感 (OS) 以及乌巴因亲和力转换 (SW)。所有小鼠品系均产生正常精子数量并且具有生育能力。所有精子类型均显示出与 WT 相当的 NKAα 同工型表达水平和活性，哇巴因抑制动力学证实了哇巴因对每种 NKA 同工型亲和力的预期变化。 1 μM 哇巴因仅阻断哇巴因敏感的 NKA，显着抑制 WT 和 OS 中的总精子活力、进行性精子活力和过度活跃精子活力，但对 OR 或 SW 精子没有显着影响。较高的哇巴因 (1 mM) 可抑制哇巴因敏感型和耐哇巴因型 NKA，对所有小鼠品系（包括 OR 和 SW）的精子活力几乎没有额外影响。哇巴因对精子细胞内钠 ([Na+]i) 的影响也存在类似的模式。这些结果表明，NKAα4（而不是 NKAα1）是精子活力的主要贡献者，并且 NKA 中的哇巴因亲和位点并不是男性生育能力的必要条件。 图文摘要
Mammalian sperm express two Na,K-ATPase (NKA) isoforms, Na,K-ATPase α4 (NKAα4) and Na,K-ATPase α1 (NKAα1). While NKAα4 is critical to sperm motility, the role of NKAα1 in sperm movement remains unknown. We determined this here using a genetic and pharmacological approach, modifying the affinity of NKAα1 and NKAα4 for the inhibitor ouabain to selectively block the function of each isoform. Sperm from wild-type (WT) mice (naturally containing ouabain-resistant NKAα1 and ouabain-sensitive NKAα4) and three newly generated mouse lines, expressing both NKAα1 and NKAα4 ouabain resistant (OR), ouabain sensitive (OS), and with their ouabain affinity switched (SW) were used. All mouse lines produced normal sperm numbers and were fertile. All sperm types showed NKAα isoform expression levels and activity comparable to WT, and kinetics for ouabain inhibition confirming the expected changes in ouabain affinity for each NKA isoform. Ouabain at 1 μM, which only block ouabain-sensitive NKA, significantly inhibited total, progressive, and hyperactivated sperm motility in WT and OS, but had no significant effect on OR or SW sperm. Higher ouabain (1 mM), which inhibits both ouabain-sensitive and ouabain-resistant NKA, had little additional effect on sperm motility in all mouse lines, including the OR and SW. A similar pattern was found for the effect of ouabain on sperm intracellular sodium ([Na+]i). These results indicate that NKAα4, but not NKAα1 is the main contributor to sperm motility and that the ouabain affinity site in NKA is not an essential requirement for male fertility.Graphic Abstract