Low acrosin activity (LAA) is associated with sperm function anomaly and poor outcomes of in vitro fertilization. In this study, we confirm that 993 semen samples with LAA had a reduced sperm motility and low in vitro fertilization rate in comparison with 1332 normal controls (NC). Proteomic comparison between 11 LAA and 11 NC sperm samples identified 35 upregulated and 99 downregulated proteins in the LAA group. Indeed, proteomic data showed that acrosome enzymes Spam1 and Acrosin were among the downregulated proteins in the LAA group, which was validated by quantitative PCR and immunefluorescent staining of sperm cells. The KEEG pathway analysis revealed a deficiency of GSH and Gln biosynthesis in LAA sperm cells. Immunofluorescent staining of sperms and quantitative PCR verified downregulation of GLUL and GCLC, the key enzymes for GSH and Gln biosynthesis. Moreover, the results of ELISA assay confirmed low levels of GSH and Gln in LAA sperm cells. Mechanistic studies showed that addition of 10 mM H₂O₂ to semen samples led to a significant reduction of acrosin activity and sperm motility, most possibly by triggering premature acrosome release. In contrast, the presence of 20 mM GSH blocked the oxidative effects of H₂O₂. Since GSH counteracts the oxidative stress and Gln participates in TCA cycling, their deficiency may affect the redox balance as well as energy production of sperm cells. These findings shed new light on the pathological mechanisms of infertility associated with LAA. Male infertility patients could benefit from GSH supplement by improvement of acrosin activity and other sperm functions.

低顶体素活性（LAA）与精子功能异常和体外受精不良结果相关。在这项研究中，我们证实，与 1332 份正常对照 (NC) 相比，993 份含有 LAA 的精液样本的精子活力降低，体外受精率较低。11 个 LAA 和 11 个 NC 精子样本之间的蛋白质组学比较发现，LAA 组中有 35 个上调蛋白质和 99 个下调蛋白质。事实上，蛋白质组学数据表明顶体酶 Spam1 和 Acrosin 是 LAA 组中下调的蛋白质之一，这通过精子细胞的定量 PCR 和免疫荧光染色得到了验证。KEEG 通路分析显示 LAA 精子细胞中 GSH 和 Gln 生物合成存在缺陷。精子的免疫荧光染色和定量 PCR 证实了 GLUL 和 GCLC（GSH 和 Gln 生物合成的关键酶）的下调。此外，ELISA 检测结果证实 LAA 精子细胞中 GSH 和 Gln 水平较低。机理研究表明，在精液样本中添加 10 mM H ₂ O ₂会导致顶体酶活性和精子活力显着降低，最有可能是通过触发顶体过早释放。相反，20 mM GSH 的存在阻断了 H ₂ O ₂的氧化作用。由于 GSH 抵消氧化应激，而 Gln 参与 TCA 循环，因此它们的缺乏可能会影响氧化还原平衡以及精子细胞的能量产生。这些发现为左心耳相关不孕症的病理机制提供了新的线索。男性不育患者可以通过补充谷胱甘肽来改善顶体酶活性和其他精子功能，从而受益。