膜联蛋白5对人精子膜及DNA完整性的影响

目的:研究膜联蛋白5(Annexin5)对人精子细胞膜及DNA完整性的影响。方法:①精子膜完整性测定:按精子浓度>20×106/ml;活率>60%选取标准收集精液标本53份,分为3组,实验组为47.5μl精液中加入2.5μl10-6mol/L的Annexin5;阴性对照组为47.5μl精液标本中加入2.5μl1mol/L的Tris-HCl(pH8.0,25℃);空白对照组为47.5μl精液标本中加入2.5μl0.01mol/L的PBS(pH7.4),作用20min后,通过精子低渗肿胀试验(HOS)检测精子膜的完整性。②DNA完整性测定:同方法①,3组实验标本作用20min后,每份标本加入2.5μl0.02mol/L的H2O2,作用60min,通过吖啶橙(AO)荧光染色检测精子核DNA的完整性。结果:An-nexin5处理20min后低渗肿胀精子百分率与空白对照组及阴性对照组比较均具有极显著差异[(66.17±12.02)%vs(58.13±13.08)%,P<0.01;(66.17±12.02)%vs(59.94±11.91)%,P<0.01];空白对照组与阴性对照组比较无显著性差异。加入H2O2后,Annexin5组的DNA碎片指数与空白对照组及阴性对照组比较均具有极显著差异[(6.39±1.07)%vs(11.16±1.16)%,P<0.01;(6.39±1.07)%vs(10.86±1.05)%,P<0.01],空白对照组与阴性对照组比较无显著性差异。结论:Annexin5蛋白能在体外提高低渗肿胀精子百分率,对精子膜的完整性具有保护作用,同时对HO作用引起的精子核DNA破坏起保护作用。     

RHO/ROCK信号通路在精子抗冷冻损伤中的作用

目的:探讨RHO/ROCK信号通路在人精子抗冷冻损伤中的作用,为高效精液冷冻保护剂的研制提供理论依据。方法:选取健康精液25份,每份精液分为新鲜组、对照组与RHO通路抑制剂组(抑制剂组)。检测冷冻前后各组精液精子活力、精子存活率、精子膜完整率、正常形态精子百分率、精子DNA碎片指数(DFI)、精子顶体酶活性及精子线粒体膜电位变化;免疫荧光染色检测RHOa/ROCK蛋白在精子中的表达。结果:抑制剂组精液冷冻复苏后精子活力[(57.50±6.83)%vs(51.20±7.70)%,P=0.002]、精子存活率[(60.24±5.53)%vs(52.87±5.07)%,P=0.001]、精子膜完整率[(67.10±4.43)%vs(59.78±5.56)%,P=0.001]、正常形态精子百分率[(7.46±1.28)%vs(4.83±1.11)%,P=0.001]、精子DFI[(18.87±4.07)%vs(27.64±6.64)%,P=0.001]、精子线粒体膜电位(63.11±2.97 vs 56.30±4.28,P=0.001)指标均明显优于对照组;抑制剂组冷冻后精子顶体酶活性与对照组差异无统计学意义(98.30±11.33 vs 97.65±9.31,P0.05)。免疫荧光染色显示RHOa/ROCK蛋白在精子头、颈部广泛表达。结论:RHO/ROCK信号通路在精子冷冻损伤中具有一定作用,抑制其通路活性可明显提高精子抗冷冻损伤的能力。     

畸形精子症患者中氧化应激与精子DNA损伤的关系探讨

目的探讨畸形精子症患者中氧化应激相关指标与精子DNA损伤变化的相关性,以期为男性不育诊治提供理论依据。方法选取2019年1月至2019年8月在河北医科大学第四医院生殖医学科诊治的101例男性不育症患者作为研究对象,按精子形态将患者精液标本分为两组,A组为精子正常形态≥4,B组为精子正常形态<4,即畸形精子症组,按世界卫生组织(WHO)精液分析第5版要求进行精液常规分析,使用伊红-苯胺黑染色方法进行精子膜完整性检测,吖啶橙荧光染色方法检测精子DNA损伤,氧化应激试剂盒检测精浆丙二醛(MDA)水平、总抗氧化能力(TAC)、超氧化物歧化酶(SOD)活性。结果与A组比较,B组的前向运动精子降低,组间比较差异有统计学意义(P<0.05);两组的精液量、精子浓度比较,差异无统计学意义(P>0.05,表1)。与A组比较,B组的精子膜完整性降低,精子DNA损伤增加,差异均有统计学意义(均P<0.05)。与A组比较,B组的TAC和SOD水平明显降低,MDA水平显著增高,差异均有统计学意义(均P<0.05)。精子正常形态率与精子DNA损伤(r=-0.492)、活性氧水平(r=-0.645)和MDA(r=-0.439)均呈负相关(均P<0.05)。精子正常形态率与TAC(r=0.623)、SOD(r=0.547)水平均呈正相关(均P<0.05)。结论氧化应激水平的改变可导致精子活力降低、精子膜完整性降低和精子DNA损伤增加。对氧化应激的检测和抗氧化的治疗可能会预防氧化应激引起的精子形态异常以及相关指标的改变,对于提高男性生育力有积极作用。     

微流控芯片精子分选法对精子常规参数及DNA完整性的影响

目的:研究微流控芯片精子优选技术对精子常规参数及DNA完整性的影响。方法:自行设计制作微流控芯片,利用芯片处理技术和上游法对40例精液标本进行精子优选,通过计算机辅助精液分析系统及染色质扩散试验从精子常规参数及DNA完整性两个方面评价精液体外处理对精子的影响。结果:精液经微流控芯片法和上游法处理后,精子活力、精子正常形态率以及精子尾部肿胀率均有显著提高(P<0.01),精子的DNA损伤率明显降低(P<0.01)。微流控芯片法与上游法相比,优选后前者精子DNA损伤率明显低于后者[(8.4±5.8)%vs(16.4±9.2)%,P<0.01],而其他参数差异无显著性。结论:微流控芯片技术在精子优选中能获得精子DNA损伤程度小的高质量精子。     

氧化胁迫与精子功能损伤

人类精子对氧化胁迫特别敏感 ,损伤精子功能的氧化胁迫有两个细胞来源 :精子自身和白细胞。由于精子膜含有高浓度的不饱和脂肪酸 ,而且精子自身的抗氧化能力很弱 ,在过量活性氧的攻击下 ,易发生脂类过氧化反应 ,使精子膜的流动性和完整性受到损伤 ,进而破坏精子功能 ,并最终引起男性不育。此外 ,过量的活性氧还可造成精子核DNA的损伤 ,而父代精子DNA的损伤又与子代儿童癌症的发生有密切的关联。     

伊红Y水试验法评价精子膜未损率及其与精液参数关系

本文建立并应用伊红Ｙ水试验法，对６１例生育男子和７２例不育男子进行精子膜完整性检测，结果表明，精子膜未损率生育组明显高于不育组。生育组和不育组的精子膜未损率均与精子尾部肿胀率、活精子百分率及精子活动率呈高度正相关，与精子正常形态百分率呈低度正相关。本法较为准确、全面、可靠，并具有简便、快速的特点，可作为精液分析的一项 常规检查方法。     

精子尾部低渗肿胀试验在评价男子生育方面的应用

本文应用精子尾部低渗肿胀试验和常规精液分析,对120例有生育力男子和693例不育男子进行了包括精子膜功能在内的综合精液质量评定。结果发现:生育组男子精子尾部低渗肿胀率明显高于不育组男子的精子肿胀率(P<0.01)。同时还发现生育组精子尾部低渗肿胀率与常规精液分析中精子活动率、精子存活率、正常形态精子百分率间呈显著正相关(r=0.3164,0.5306,0.3034,P<0.0005,<0.0005,<0.005)。实验证明,精子低渗尾部肿胀试验是一种有价值的评价精子功能的方法。     

伊红Y水试验法的临床应用研究

用伊红Ｙ水试验法，对生育组和不育组男子精液进行了精子膜完整性检测，包括：①精子头部未着色率，②精子尾部肿胀率，③ｇ型精子百分率以及④精子膜未损率。结果显示，生育组的以上４项指标均明显高于不育组（Ｐ＜０．００１）。这表明，伊红Ｙ水试验法是评价男性生育能力的有效方法。     

60KD的精子膜抗原对抗精子抗体阳性精子顶体酶活性的影响

目的观察60KD精子膜抗原对抗体阳性精子顶体酶活性的影响。方法用全胶电洗脱结合连续电洗脱的方法提取60KD精子膜抗原,使用60KD精子膜抗原体外处理抗精子抗体阳性精子。精子顶体酶活性的检测采用固定明胶底物薄膜法。结果抗精子抗体阳性精子经60KD抗原处理后,精子的凝集率由处理前的(35.115.1)%下降到了(13.03.3)%(P<0.001)。精子顶体酶阳性反应率由处理前的(30.37.3)%升高到(56.49.1)%(P<0.001)。结论60KD精子膜抗原可以有效去除精子结合的抗体,并提高精子的顶体酶活性。     

伊红Y水试验法评价精子膜未损率及其与精液参数关系

本文建立并应用伊红Ｙ水试验法，对６１例生育男子和７２例不育男子进行精子膜完整性检测。结果表明，精子膜未损率生育组明显高于不育组。生育组和不育组的用子膜未报率均与精子尾部肿胀率、活精子百分率及精子活动率呈高度正相关，与精子正常形态百分率呈低度正相关。本法较为准确、全面、可靠，并具有简便、快速的特点，可作为精液分析的一项常规检测方法。     

Nicotinic infertility: assessing DNA and plasma membrane integrity of human spermatozoa

Infertility remains a major problem in society, with recent data suggesting its presence in one of four couples. The objective of the present study was to evaluate the impact of nicotine (0.25, 0.5 and 0.75 mm), as a major component of cigarette smoke, in vitro, on sperm membrane [by spermatocrit and lipoperoxidation (LPO) tests], DNA integrity (by Comet assay), and viability of spermatozoa (by eosin staining) from normozoospermic men. Sperm samples were washed and diluted with phosphate-buffered saline. A drop in spermatocrit values and an increase in thiobarbituric acid-reactive substances/LPO rate was observed with the addition of nicotine, predominantly at a concentration of 0.75 mm, indicating a deleterious effect of nicotine on sperm membrane intactness. There was also a strong negative correlation between LPO rate and percentage viable sperm cell (r = -0.990). Data obtained from Comet assay technique revealed that nicotine could induce double-stranded DNA breaks (11% in 0.75 mm concentration) in the sperm nuclei. The value of r between LPO rate and percentage Comets was found to be +0.976. Taken together, nicotine proved to be a potential oxidant agent in the category of environmental factors to the integrity of sperm plasma membrane and DNA.     

Catalase supplementation on thawed bull spermatozoa abolishes the detrimental effect of oxidative stress on motility and DNA integrity

The potential protective effect of catalase supplementation during in vitro culture of frozen/thawed bull spermatozoa was investigated. Frozen/thawed semen collected from three fighting bulls was diluted in phosphate buffered saline (PBS) and incubated at 37 °C under different experimental conditions: Control, Catalase (CAT) (200 U/mL), Oxidant (OXI) (100 μ m Fe²⁺/1 m m ascorbate), and Catalase + Oxidant (CAT/OXI). We assessed sperm motility, acrosomal integrity, viability and chromatin status (SCSA®) at 0, 2 and 6 h of incubation. Our results showed that catalase abolished the effect of the oxidant, protecting spermatozoa against reactive oxygen species, and improving both sperm motility and chromatin status during incubation. The OXI treatment significantly reduced the percentage of motile sperm after 6 h of incubation. The statistical model also showed that there were differences in sperm motility between CAT/OXI (20.8 ± 2.9%) and OXI (11.6 ± 7.6%) ( p  < 0.001). There were no significant effects of OXI on sperm viability, acrosomal status or proportion of abnormal tails. %DFI (spermatozoa with moderate or high DNA Fragmentation Index) was significantly higher on OXI ( p  < 0.001). Catalase prevented DNA fragmentation even in the presence of the oxidant (%DFI: 30.3 ± 0.8% OXI vs. 17.4 ± 0.7% CAT/OXI). We conclude that catalase supplementation after thawing could protect bull spermatozoa against oxidative stress, and it could improve media used for processing thawed spermatozoa.     

Assessment of the effect of testosterone on the acrosome reaction of human spermatozoa

In the acrosome reaction, the spermatozoon plasma membrane fuses with the outer acrosomal membrane, resulting in the release of the acrosomal content. Several compounds, such as sex steroids, are known to modulate the acrosomal exocytosis. Testosterone regulates various functions in male reproductive physiology; however, little is known about the relationship between testosterone and the acrosome reaction. Thus, our objective was to study the effect of testosterone on the acrosome reaction of human spermatozoa. To evaluate the acrosomal exocytosis, spermatozoa were incubated with testosterone (0.2, 2.0 and 20 nmol l(-1)), progesterone and control medium for 60, 120, 240 and 1440 min. The acrosome reaction was assessed by staining with Hoechst 33258 and fluorescein isothiocyanate-conjugated P. sativum agglutinin lectin. In general, spermatozoa incubated with progesterone had the highest percentage of acrosomal exocytosis. The percentage of acrosome reaction obtained in the three treatments with testosterone differed from that observed for progesterone at 120, 240 and 1440 min (24 h). Additionally, significant differences were found between testosterone (2.0 and 20 nmol l(-1)) and progesterone after 60 min. Differences between control and the three testosterone treatments studied were obtained only at 1440 min. In general terms, these results show that testosterone exerts no inductor effects on the acrosome reaction of human spermatozoa.     

Evolution and Development of the Outer Acrosomal Membrane (OAM) and Evidence that Acrosin-lnhibitors are Proteins of the OAM

An antiserum to the purified porcine outer acrosomal membrane (OAM) was raised in rabbits and the IgG fraction isolated by ammonium sulphate precipitation and ion exchange chromatography. The antibodies reacted exclusively with the acrosomal cap of the sperm head as revealed by indirect immunofluorescence. In addition they cross-reacted not only with the acrosomal part of the spermatozoa of all mammalian species tested (bull, horse, rabbit, rat, mouse, hamster, mole, antelope, monkey, man) but also with the spermatozoa of the cock (Class: birds) and the rainbow trout (Class: fish). All the species exhibited similar development of the acrosomal cap during spermatogenesis, with the appearance of the immunofluorescent stain in early round spermatids. In the mole the localization of the acrosome in elongated testicular spermatids differed from that in all other species: Instead of prominent fluorescence over the apical part of the sperm an equatorial belt was formed. The cross-reactivity of the anti-boar OAM antibody with the acrosomes of different vertebrate species at the morphological level was supported by the results of Western blotting experiments with purified boar OAM proteins and the SDS-extractable proteins of bull and human spermatozoa, respectively. Using anti-OAM antibodies and antibodies against the acrosin inhibitors I and II described recently by Tschesche et al. (1982), in absorption and Western blotting experiments, it was demonstrated that the acrosin inhibitor proteins are integrated in the outer acrosomal membrane.     

Actin and actin-binding proteins in bovine spermatozoa: potential role in membrane remodeling and intracellular signaling during epididymal maturation and the acrosome reaction

The actin cytoskeleton influences a wide range of functions in nonmuscle somatic cells, including shape, movement, and interactions with extracellular matrices. The role of actin in mammalian male germ cells, however, particularly during post-testicular development, is not well understood. In this paper, we examine 1) the distribution of 3 actin-regulatory proteins (thymosin beta10, destrin, and a testis-specific actin capping protein) involved in controlling the balance between actin monomers (G-actin) and actin filaments (F-actin), and 2) the distribution and polymerization status of actin in bull spermatozoa during epididymal maturation and following acrosomal exocytosis. Results show that in fixed, permeabilized testicular spermatozoa all 3 regulatory proteins (as determined by binding of specific antibodies) are localized primarily to the acrosomal domain but during epididymal maturation they become confined to the equatorial segment. Following ejaculation, however, they extend back into the acrosomal region. In spermatozoa induced to undergo an acrosome reaction with the calcium ionophore, A23187, further rearrangement occurs with destrin, thymosin beta10, and TS-ACP appearing in the postacrosomal domain. Actin is also found over the acrosome of testicular spermatozoa with both G- and F-actin present, although the 2 forms show slightly different patterns of distribution. Subsequently, actin in the sperm head is largely confined to the equatorial segment until F-actin appears in the postacrosomal domain of acrosome-reacted spermatozoa. This redistribution of actin and actin-regulatory proteins, coupled with changing levels of actin polymerization, suggest a continuing role for actin in both post-testicular sperm maturation and acrosomal exocytosis.     

Comparison and evaluation of capacitation and acrosomal reaction in freeze‐thawed human ejaculated spermatozoa treated with L‐carnitine and pentoxifylline

Cryopreservation is used to preserve the spermatozoa; however, it leads to a reduction in sperm quality. L‐carnitine (LC) influences sperm motility and preserves the sperm membrane and DNA integrity. The objectives of this study were to evaluate the protective effects of LC on the membrane integrity of normal human spermatozoa and compare it with pentoxifylline (PT) during cryopreservation. Thirty normal semen samples, prepared by swim‐up procedure, were divided into three aliquots: a control without any treatment and two experimental aliquots that were incubated in PT or LC for 30 min. All aliquots were cryopreserved and thawed after 48 hr. To evaluate the percentages of intact, acrosomal‐reacted and capacitated spermatozoa, lectin histochemistry and flow cytometry were performed by wheat germ agglutinin, peanut agglutinin and Con A. Statistical analyses were performed using ANOVA. LC supplementation elevated the percentage of noncapacitated spermatozoa compared with control and PT‐treated samples and the percentages of acrosomal intact spermatozoa compared with PT‐treated samples. PT pre‐treatment improved the motility but not membrane integrity. LC supplementation reduced the percentages of acrosomal‐reacted spermatozoa compared with the control and PT‐treated samples. Although LC did not improve motility, it protected the plasma membrane and acrosomal integrity. Therefore, LC may be the superior choice compared to PT for maintaining the sperm integrity.     

Effects of discontinuous Percoll gradient centrifugation on the quality of bovine spermatozoa evaluated with computer-assisted semen analysis and fluorescent probes association

The objective of this study was to evaluate the quality of bovine frozen-thawed sperm cells after Percoll gradient centrifugation. Frozen semen doses were obtained from six bulls of different breeds, including three taurine and three Zebu animals. Four ejaculates per bull were evaluated before and after discontinuous Percoll gradient centrifugation. Sperm motility was assessed by computer-assisted semen analysis and the integrity of the plasma and acrosomal membranes, as well as mitochondrial function, were evaluated using a combination of fluorescent probes propidium iodide, fluorescein isothiocyanate-conjugated Pisum sativum agglutinin and 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide. The procedure of Percoll gradient centrifugation increased the percentage of total and progressive sperm motility, beat frequency, rectilinear motility, linearity and rapidly moving cells. In addition, the percentage of cells with intact plasma membrane and mitochondrial membrane potential was increased in post-centrifugation samples. However, the percentage of sperm cells with intact acrosomal membrane was markedly reduced. The method used selected the motile cells with intact plasma membrane and higher mitochondrial functionality in frozen-thawed bull semen, but processing, centrifugation and/or the Percoll medium caused damage to the acrosomal membrane.     

The Sperm Acrosome: Immunological Analysis using Specific Polyclonal and Monoclonal Antibodies Directed Against the Outer Acrosomal Membrane of Boar Spermatozoa

An antiserum to the purified porcine outer acrosomal membrane (OAM) was raised in female Balb/c mice and was characterized by means of an indirect ELISA. The hyperimmune serum reacted selectively with the acrosomal cap of the sperm head and showed an extremely good cross reactivity with bull and human spermatozoa when assayed by indirect immunofluorescence. Immunoelectron microscopy using the protein A-gold method further confirmed the specificity of the anti-OAM-antiserum for the OAM. In an effort to identify the OAM antigens recognized by the hyperimmune serum and to analyse the extent of cross reactivity on a molecular level, the SDS-extractable proteins were separated by SDS-PAGE, transblotted and immunoprinted using an 125J-conjugated anti-mouse-antibody. To facilitate functional and structural analysis of distinct OAM-proteins monoclonal antibodies were generated by hybridization of mouse myeloma cells with the splenocytes of female Balb/c mice immunized with the purified OAM. One fusion resulted in about 100 anti-OAM-antibodies secreting hybridoma cultures, of which about 30% showed cross reaction with human and bull spermatozoa. Four stable cell lines were selected for this study secreting antibodies directed against the outer acrosomal membrane of boar spermatozoa. Whereas the polyclonal immune mouse serum stained the entire acrosomal cap, the four hybridoma antibodies generated a patch-work-like immunofluorescence pattern over the acrosome. HPLC-ELISA of the solubilized OAM revealed first information on the nature of the corresponding membrane antigen.     

In vitro tests for essential sperm functions using the phyto-oestrogen genistein as a test substance

Sperm motility, binding of spermatozoa to the zona pellucida and induction of the acrosome reaction are prerequisites for successful oocyte fertilization. Examination of the physiological and nonphysiological effects of particular compounds on sperm functions requires high-quality in vitro test systems. In this short methodological overview, a reliable combined in vitro test system with bovine gametes is described. The purpose of the study was to evaluate whether aliquots of pooled post-thaw spermatozoa are suitable for examination of environmental substances that affect essential sperm functions. The combined test system includes a number of known methods for the assessment of sperm vitality and motion parameters, acrosomal status, inducibility of acrosome reaction and sperm zona pellucida binding. First observations indicate that genistein inhibits the induction of acrosomal exocytosis and binding of spermatozoa to the zona pellucida. Motility parameters and the viability of bovine spermatozoa were not affected by this substance. It is concluded that genistein, a phyto-oestrogen which is abundant in several plants, can be used as a test substance for the evaluation of effects upon essential bovine sperm functions in vitro.     

冻存后大鼠精子活力变化与其结构的关系

目的　观察冷冻对大鼠精子活动能力的影响 ,并探讨其活动能力的变化与细胞膜完整性、DNA结构、线粒体鞘和顶体的关系。　方法　使用计算机辅助精子活动分析仪 (CASA)检测冻存前后大鼠精子活动力的变化 ;荧光素乙酰乙酸盐 (FDA)染色法检测大鼠精子细胞膜的完整性 ;双氢鲁丹明荧光反应观察精子线粒体鞘的变化 ;金霉素 (CTC)荧光检测法观察冻存对大鼠精子顶体的影响。　结果　复苏后精子的活动力下降 ,为冻存前的 39.7% ;FDA检测显示冻存后的大鼠精子细胞膜完整 ,未受到破坏 ;冻存后的大鼠精子线粒体鞘荧光强度下降 ,且荧光不连续、甚至消失 ;CTC荧光反应显示冻存后精子顶体反应 (AR)的类型发生改变 ,AR型精子比例明显下降 ,由冻存前的 6 8.6 %降至冻存后的 13.4 %。　结论　冻存后大鼠精子细胞膜的完整性未受到破坏 ;精子的线粒体鞘和顶体受到较明显的破坏。大鼠精子冻存复苏后活力下降与线粒体鞘和AR存在相关性。