Steeman Tomás J, Baro Graf Carolina, Novero Analia G, Buffone Mariano G, Krapf Dario
Instituto de Biología Molecular y Celular de Rosario (IBR CONICET-UNR), Rosario 2000, Argentina.
Instituto de Biología y Medicina Experimental (IBYME-CONICET), Buenos Aires 1428, Argentina.
Biology (Basel). 2025 Jul 12;14(7):851. doi: 10.3390/biology14070851.
Sperm membrane potential (m) hyperpolarization during capacitation is a functional hallmark of fertilizing ability and has been proposed as a predictive biomarker for conventional in vitro fertilization (IVF) success. However, it is unclear whether m remains stable across ejaculates over time and can reliably guide assisted reproductive technology (ART) decisions in advance. Thus, we aimed to evaluate the temporal consistency of human sperm m within individuals and assess its utility as a prognostic marker when measured days or weeks prior to IVF procedures. m was assessed in capacitated and non-capacitated sperm from normospermic donors at three time points over 28 days, using a fluorometric assay. Capacitated values were compared to a -48.6 mV threshold previously associated with successful fertilization. Intra-donor m variability and coefficients of variation (CV) were analyzed statistically. Our results showed that m values exhibited significant intra-donor variability over time ( = 0.007), with approximately half of the donors crossing the -48.6 mV functional threshold across sessions. Capacitated sperm samples showed significantly greater variability than non-capacitated ones, with several donors exceeding a 30% CV cutoff. No consistent correlation was found between CV and mean m values. While m remains a promising functional marker when assessed on the day of IVF, its temporal variability undermines its reliability as a predictive tool for ART decisions made in advance. These findings underscore the importance of timing in functional sperm assessments and call for further studies to identify the physiological factors influencing m stability.
精子获能过程中的膜电位（m）超极化是受精能力的一个功能标志，并且已被提议作为传统体外受精（IVF）成功的预测生物标志物。然而，目前尚不清楚m随时间在不同射精样本中是否保持稳定，以及能否提前可靠地指导辅助生殖技术（ART）决策。因此，我们旨在评估个体内人类精子m的时间一致性，并在IVF程序前数天或数周进行测量时，评估其作为预后标志物的效用。使用荧光测定法，在28天内的三个时间点对正常精子捐献者的获能和未获能精子进行m评估。将获能值与先前与成功受精相关的-48.6 mV阈值进行比较。对捐献者内部的m变异性和变异系数（CV）进行统计分析。我们的结果表明，m值随时间表现出显著的捐献者内部变异性（ = 0.007），约一半的捐献者在不同时间段内超过了-48.6 mV的功能阈值。获能精子样本的变异性显著大于未获能精子样本，有几个捐献者超过了30%的CV临界值。未发现CV与平均m值之间存在一致的相关性。虽然在IVF当天评估时m仍然是一个有前景的功能标志物，但其时间变异性削弱了其作为提前进行ART决策的预测工具的可靠性。这些发现强调了功能性精子评估中时间的重要性，并呼吁进一步研究以确定影响m稳定性的生理因素。
