Arya Deepshikha, Pawar Prakash, Gajbhiye Rahul, Tandon Deepti, Kothari Priyank, Goankar Reshma, Singh Dipty
Department of Neuroendocrinology, ICMR-National Institute for Research in Reproductive and Child Health, Parel, Mumbai, 400012, India.
Lokmanya Tilak Municipal General Hospital, Sion, Mumbai, 400022, India.
Mol Cell Endocrinol. 2025 Jan 1;595:112393. doi: 10.1016/j.mce.2024.112393. Epub 2024 Oct 30.
Varicocele has been associated with reduced male fertility potential. Treatment modalities for varicocele improve semen parameters, yet more than 50% of cases remain infertile. Varicocele-induced heat and hypoxia stress may affect sperm mitochondrial functions, possibly leading to aberrant epigenetic modifications. This study includes 30 fertile men and 40 infertile men with clinical varicocele. The effect of varicocele treatment (antioxidant supplementation and or varicocelectomy) was evaluated after 3 months of treatment. Mitochondrial membrane potential (MMP) and intracellular reactive oxygen species (iROS) were measured by flow cytometry using JC-1 and DCFDA, respectively. mtDNA copy number and deletions were determined by PCR. DNA methylation was analysed by pyrosequencing. Present investigations suggest that infertile men with varicocele have abnormal semen parameters; significantly low MMP, high iROS, and high mtDNA copy number. Semen parameters were improved in a subset of men of both the treatment modalities; however, it was noted that varicocelectomy helped better in improving sperm parameters compared to antioxidant treatment. Both treatment modalities helped in reducing iROS and mtDNA copy number significantly; however, they were noneffective in improving MMP. Altered DNA methylation at mitochondria D loop and mitochondrial structure and function genes UQCRC2, MIC60, TOM22, and LETM1 (promoter region) were observed in varicocele group. The DNA methylation levels were restored after varicocele treatment; however, the restoration was not consistent at all CpG sites. Both the treatment modalities helped in restoring the altered DNA methylation levels of mitochondrial genes but the restoration is nonhomogeneous across the studied CpG sites.
精索静脉曲张与男性生育潜力降低有关。精索静脉曲张的治疗方法可改善精液参数，但超过50%的病例仍无法生育。精索静脉曲张引起的热应激和缺氧应激可能影响精子线粒体功能，可能导致异常的表观遗传修饰。本研究纳入了30名有生育能力的男性和40名患有临床精索静脉曲张的不育男性。在治疗3个月后评估精索静脉曲张治疗（补充抗氧化剂和/或精索静脉结扎术）的效果。分别使用JC-1和DCFDA通过流式细胞术测量线粒体膜电位（MMP）和细胞内活性氧（iROS）。通过PCR测定线粒体DNA（mtDNA）拷贝数和缺失情况。通过焦磷酸测序分析DNA甲基化。目前的研究表明，患有精索静脉曲张的不育男性精液参数异常；MMP显著降低、iROS升高以及mtDNA拷贝数升高。两种治疗方式均使一部分男性的精液参数得到改善；然而，值得注意的是，与抗氧化剂治疗相比，精索静脉结扎术在改善精子参数方面效果更好。两种治疗方式均有助于显著降低iROS和mtDNA拷贝数；然而，它们在改善MMP方面无效。在精索静脉曲张组中观察到线粒体D环以及线粒体结构和功能基因UQCRC2、MIC60、TOM22和LETM1（启动子区域）的DNA甲基化发生改变。精索静脉曲张治疗后DNA甲基化水平得以恢复；然而，在所有CpG位点的恢复并不一致。两种治疗方式均有助于恢复线粒体基因改变的DNA甲基化水平，但在所研究的CpG位点上恢复并不均匀。
