Hyperpolarization induces cytosolic alkalization of mouse sperm flagellum probably through sperm Na+/H+ exchanger

Author:

Hernández-Garduño Sandra1,Chávez Julio C1,Matamoros-Volante Arturo1,Sánchez-Guevara Yoloxochitl1,Torres Paulina1,Treviño Claudia L1,Nishigaki Takuya1ORCID

Affiliation:

1. Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México

Abstract

In brief Hyperpolarization of the membrane potential is a crucial step for mammalian sperm maturation. This work demonstrates that this membrane potential change likely activates a sperm-specific sodium/proton exchanger to induce alkalization in mouse sperm flagellum. Abstract The sperm-specific sodium/proton exchanger (sNHE) is an indispensable protein for male fertility in mammals. Nevertheless, it is still unknown how mammalian sNHE is regulated. Evidence obtained from sea urchin sNHE indicates that hyperpolarization of plasma membrane potential (Vm), which is a hallmark of mammalian capacitation, positively regulates the sNHE. Therefore, we explored the activity of sNHE in mouse and human sperm by fluorescence imaging of intracellular pH (pHi) with a ratiometric dye, SNARF-5F. A valinomycin-induced Vm hyperpolarization elevated sperm flagellar pHi of WT mouse but not in sNHE-KO mouse. Moreover, this pHi increase was inhibited in a high K+ (40 mM) medium. These results support the idea that mouse sNHE is activated by Vm hyperpolarization. Interestingly, we observed different types of kinetics derived from valinomycin-induced alkalization, including some (30%) without any pHi changes. Our quantitative pHi determinations revealed that unresponsive cells had a high resting pHi (>7.5), suggesting that the activity of mouse sNHE is regulated by the resting pHi. On the other hand, valinomycin did not increase the pHi of human sperm in the head or the flagellum, regardless of their resting pHi values. Our findings suggest that the regulatory mechanisms of mammalian sNHEs are probably distinct depending on the species.

Publisher

Bioscientifica

Subject

Cell Biology,Obstetrics and Gynecology,Endocrinology,Embryology,Reproductive Medicine

Reference64 articles.

1. Control of the low voltage-activated calcium channel of mouse sperm by egg ZP3 and by membrane hyperpolarization during capacitation;Arnoult,1999

2. Observations on the penetration of the sperm into the mammalian egg;Austin,1951

3. Molecular mechanism underlying the action of zona-pellucida glycoproteins on mouse sperm;Balbach,2020

4. Membrane hyperpolarization abolishes calcium oscillations that prevent induced acrosomal exocytosis in human sperm;Balestrini,2020

5. Determination of a robust assay for human sperm membrane potential analysis;Baro,2019

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3