Singh Vertika, Kumar Mohanty Sujit, Verma Priyanka, Chakraborty Arijit, Trivedi Sameer, Rajender Singh, Singh Kiran
Department of Molecular & Human Genetics, Banaras Hindu University, Varanasi, India.
Division of Endocrinology, Central Drug Research Institute, Lucknow, India.
Mutat Res Genet Toxicol Environ Mutagen. 2019 Mar;839:1-8. doi: 10.1016/j.mrgentox.2019.01.004. Epub 2019 Jan 15.
High fidelity DNA repair is critical to sustain the genomic integrity and quality of developing germ cells. Deficiencies in DNA repair machinery may result in increased DNA damage in germ cell leading to abnormal spermatogenesis and infertility. X-ray repair cross-complementing group 1 (XRCC1) is a testis enriched protein that plays a crucial role in the DNA base excision repair (BER) pathway. The aim of this study was to analyze the level of XRCC1 transcript and protein in infertile men and its association with DNA damage in sperm. A total of eighty infertile patients with different infertile phenotypes (Azoospermia, n = 30; Severe oligozoospermia, n = 25; Severe oligoasthenozoospermia, n = 25) and age-matched controls (normal spermatogenesis [NS], n = 15 and fertile controls, n = 10) were recruited. γ-H2 AX protein levels were analyzed to estimate the DNA damage in sperm. XRCC1 transcript levels in cases and controls were determined by qRT-PCR. XRCC1 and γ-H2 AX proteins were immunohistochemically analyzed in testicular biopsy sections obtained from NOA patients and OA controls. The determination of XRCC1 and γ-H2 AX protein levels was performed with Western blots. The results revealed reduced expression of XRCC1 mRNA and protein in infertile individuals as compared to controls (p < 0.001). γ-H2 AX levels were significantly increased in infertile cases as compared to controls, indicating increased DNA damage in infertile men. The results indicate decreased expression of the XRCC1 gene in infertile patients which may be one of the factors associated with impaired spermatogenesis and infertility.
高保真DNA修复对于维持发育中的生殖细胞的基因组完整性和质量至关重要。DNA修复机制的缺陷可能导致生殖细胞中DNA损伤增加，从而导致异常精子发生和不育。X射线修复交叉互补基因1（XRCC1）是一种在睾丸中富集的蛋白质，在DNA碱基切除修复（BER）途径中起关键作用。本研究的目的是分析不育男性中XRCC1转录本和蛋白质的水平及其与精子DNA损伤的关系。共招募了80名具有不同不育表型的不育患者（无精子症，n = 30；严重少精子症，n = 25；严重少弱精子症，n = 25）以及年龄匹配的对照组（正常精子发生[NS]，n = 15和生育对照组，n = 10）。分析γ-H2AX蛋白水平以评估精子中的DNA损伤。通过qRT-PCR测定病例组和对照组中XRCC1转录本水平。对从非梗阻性无精子症患者和梗阻性无精子症对照组获得的睾丸活检切片进行XRCC1和γ-H2AX蛋白的免疫组织化学分析。用蛋白质印迹法测定XRCC1和γ-H2AX蛋白水平。结果显示，与对照组相比，不育个体中XRCC1 mRNA和蛋白质的表达降低（p < 0.001）。与对照组相比，不育病例中γ-H2AX水平显著升高，表明不育男性的DNA损伤增加。结果表明，不育患者中XRCC1基因的表达降低，这可能是与精子发生受损和不育相关的因素之一。
