Roa-Espitia Ana L, Reyes-Miguel Tania, Salgado-Lucio Monica L, Cordero-Martínez Joaquín, Tafoya-Domínguez Dennis, Hernández-González Enrique O
Department of Cell Biology, Center of Research and Advanced Studies of the National Polytechnic Institute, México Av. Instituto Politécnico Nacional 2508, México City 07360, Mexico.
Department of Health Sciences, Division of Biological and Health Sciences, Universidad Autónoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco No. 186, Colonia Vicentina, Alcaldía Iztapalapa, México City 09310, Mexico.
Int J Mol Sci. 2025 Apr 16;26(8):3750. doi: 10.3390/ijms26083750.
Mammalian spermatozoa undergo a series of physiological and biochemical changes in the oviduct that lead them to acquire the ability to fertilize eggs. During their transit in the oviduct, spermatozoa face a series of environmental changes that can affect sperm viability. A series of ion channels and transporters, as well as the sperm cytoskeleton, allow spermatozoa to remain viable and functional. Cl channels such as TMEM16A (calcium-activated chloride channel), CFTR (cystic fibrosis transmembrane conductance regulator), and ClC3 (chloride voltage-gated channel 3) are some of the ion transporters involved in maintaining cellular homeostasis. They are expressed in mammalian spermatozoa and are associated with capacitation, acrosomal reaction, and motility. However, little is known about their role in maintaining sperm volume. Therefore, this study aimed to determine the mechanism through which TMEM16A maintains sperm volume during capacitation. The effects of TMEM16A were compared to those of CFTR and ClC3. Spermatozoa were capacitated in the presence of specific TMEM16A, CFTR, and ClC3 inhibitors, and the results showed that only TMEM16A inhibition increased acrosomal volume, leading to changes within the acrosome. Similarly, only TMEM16A inhibition prevented actin polymerization during capacitation. Further analysis showed that TMEM16A inhibition also prevented ERK1/2 and RhoA activation. On the other hand, TMEM16A and CFTR inhibition affected both capacitation and spontaneous acrosomal reaction, whereas ClC3 inhibition only affected the spontaneous acrosomal reaction. In conclusion, during capacitation, TMEM16A activity regulates acrosomal structure through actin polymerization and by regulating ERK1/2 and RhoA activities.
哺乳动物的精子在输卵管中会经历一系列生理和生化变化，从而获得使卵子受精的能力。在它们于输卵管中运输的过程中，精子面临一系列可能影响其活力的环境变化。一系列离子通道、转运蛋白以及精子细胞骨架使精子能够保持活力并发挥功能。诸如TMEM16A（钙激活氯离子通道）、CFTR（囊性纤维化跨膜传导调节因子）和ClC3（氯离子电压门控通道3）等氯离子通道是参与维持细胞内稳态的一些离子转运蛋白。它们在哺乳动物精子中表达，并与获能、顶体反应和运动性相关。然而，关于它们在维持精子体积方面的作用却知之甚少。因此，本研究旨在确定TMEM16A在获能过程中维持精子体积的机制。将TMEM16A的作用与CFTR和ClC3的作用进行了比较。在存在特定的TMEM16A、CFTR和ClC3抑制剂的情况下使精子获能，结果表明只有抑制TMEM16A会增加顶体体积，导致顶体内发生变化。同样，只有抑制TMEM16A会阻止获能过程中的肌动蛋白聚合。进一步分析表明，抑制TMEM16A还会阻止ERK1/2和RhoA的激活。另一方面，抑制TMEM16A和CFTR会影响获能和自发顶体反应，而抑制ClC3仅影响自发顶体反应。总之，在获能过程中，TMEM16A的活性通过肌动蛋白聚合以及调节ERK1/2和RhoA的活性来调节顶体结构。
