Participation of the Cl-/HCO3- Exchangers SLC26A3 and SLC26A6, the Cl- Channel CFTR, and the Regulatory Factor SLC9A3R1 in Mouse Sperm Capacitation
Participation of the Cl-/HCO3- Exchangers SLC26A3 and SLC26A6, the Cl- Channel CFTR, and the Regulatory Factor SLC9A3R1 in Mouse Sperm Capacitation
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DOI：
10.1095/biolreprod.111.094037
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发表时间：
2012-01-01
影响因子：
3.6
通讯作者：
Trevino, Claudia L.
中科院分区：
文献类型：
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作者：
Chavez, Julio C.;Hernandez-Gonzalez, Enrique O.;Trevino, Claudia L.
精子获能是受精所必需的，涉及到几个离子渗透性的变化。虽然Cl-和HCO3-对能化至关重要，但负责它们运输的分子实体尚不完全清楚。在小鼠精子获能过程中，细胞内Cl- ([Cl-](i))浓度增加，膜电位（Em）超极化。与未获能精子一样，Cl-平衡电位似乎接近细胞静息时的Em， Cl-通道的打开不能支持获能过程中观察到的[Cl-](i)的增加。或者，[Cl-](i)的增加可能是由阴离子交换剂介导的。其中，SLC26A3和SLC26A6是很好的候选者，因为在几种细胞类型中，它们增加[Cl-](i)并与囊性纤维化跨膜传导调节剂（CFTR）相互作用，CFTR是小鼠和人类精子中存在的一种Cl-通道。已知这种相互作用是由Na+/H+调节因子-1（官方代码SLC9A3R1）介导和调控的。我们的RT-PCR、免疫细胞化学、Western blot和免疫沉淀数据表明，SLC26A3、SLC26A6和SLC9A3R1在小鼠精子中表达，定位于中间，相互作用并与CFTR相互作用。此外，我们提供的证据表明，CFTR和SLC26A3参与了db-cAMP诱导的无能力精子[Cl-](i)增加。此外，我们发现SLC26A3抑制剂（Tenidap和5099）干扰伴随获能的Em变化。总之，这些发现表明CFTR/SLC26A3功能相互作用对小鼠精子获能很重要。
Sperm capacitation is required for fertilization and involves several ion permeability changes. Although Cl- and HCO3- are essential for capacitation, the molecular entities responsible for their transport are not fully known. During mouse sperm capacitation, the intracellular concentration of Cl- ([Cl-](i)) increases and membrane potential (Em) hyperpolarizes. As in noncapacitated sperm, the Cl- equilibrium potential appears to be close to the cell resting Em, opening of Cl- channels could not support the [Cl-](i) increase observed during capacitation. Alternatively, the [Cl-](i) increase might be mediated by anion exchangers. Among them, SLC26A3 and SLC26A6 are good candidates, since, in several cell types, they increase [Cl-](i) and interact with cystic fibrosis transmembrane conductance regulator (CFTR), a Cl- channel present in mouse and human sperm. This interaction is known to be mediated and probably regulated by the Na+/H+ regulatory factor-1 (official symbol, SLC9A3R1). Our RT-PCR, immunocytochemistry, Western blot, and immunoprecipitation data indicate that SLC26A3, SLC26A6, and SLC9A3R1 are expressed in mouse sperm, localize to the midpiece, and interact between each other and with CFTR. Moreover, we present evidence indicating that CFTR and SLC26A3 are involved in the [Cl-](i) increase induced by db-cAMP in noncapacitated sperm. Furthermore, we found that inhibitors of SLC26A3 (Tenidap and 5099) interfere with the Em changes that accompany capacitation. Together, these findings indicate that a CFTR/SLC26A3 functional interaction is important for mouse sperm capacitation.