DEAD box家族蛋白与精子生成的研究进展

精子的发生和成熟过程不但需要多种相关基因正确表达,而且还需要多种RNA的参与.因此,这些RNA需要较好的稳定性以保证其功能的正确执行.DEAD-box家族蛋白是一个ATP依赖的RNA解旋酶家族,参与RNA的各种代谢过程如RNA二级结构变换,转录起始,线粒体RNA剪接,核糖体和剪接体装配、mRNA降解以及维持mRNA的稳定性等.最近的一些研究显示这个家族的一些成员如DDX3,DDX4,DDX25等与精子生成有着密切的关系.     

Hormonal approaches to male contraception: approaching reality

The ‘pre-testicular’ suppression of gonadotrophins is the most likely approach for reversible therapeutic male fertility control to reach imminent clinical application. Maintenance of spermatogenesis depends on adequate gonadotrophin and intratesticular testosterone concentrations. Hormonal contraception for men interrupts this physiological axis by various means of gonadotrophin suppression; this interferes with spermatogonial differentiation and meiosis entry resulting in reversible azoospermia or severe oligozoospermia in virtually all men. Clinical trials have confirmed that high contraceptive efficacy, similar to female hormonal contraceptives, can be reliably attained with few side effects. However, the simultaneous suppression of Leydig cell steroidogenesis mandates the requirement for testosterone replacement in hormonal male contraception. Combination regimens of new synthetic progestins and androgens at various stages of development are being investigated with the lead products poised to go into phase III trials. Heterogeneity in response to spermatogenesis suppression has been observed within and between population; the mechanisms are unclear. This new method of reversible and effective contraception has registered high acceptability in surveys of both men and women. The recent entry of pharmaceutical companies into this area of research and development has considerably enhanced the prospects of translating years of academic efforts into new products which provide added family planning choice for many couples.     

小鼠精子发生过程中雄激素受体对靶基因Septin7的表达调控

目的:探讨雄激素受体(AR)对睾丸Sertoli细胞中Septin 7基因表达的影响。方法:分别采用实时荧光定量PCR及Western blot,检测睾丸Sertoli细胞AR特异性敲除(S-AR-/y)和野生型小鼠(WT)睾丸Sertoli细胞中SEPTIN 7的表达,并观察雄激素对过表达AR的Sertoli细胞系TM4中SEPTIN 7表达的影响。结果:与WT小鼠相比,S-AR-/y中Septin 7 mRNA表达水平升高(P0.05);雄激素显著降低TM4中SEPTIN 7表达(P0.05)。结论:Septin 7可能是睾丸Sertoli细胞中AR调控的靶基因。该研究对阐明雄激素及其受体调节精子发生的分子机理具有重要意义。     

Ultrastructural observations on nucleoli and related structures during human spermatogenesis

Summary The ultrastructural study of nucleoli and ribonucleoprotein-containing structures in human seminiferous tubules revealed that the nucleoli of spermatogonia, spermatocytes and Sertoli cells exhibited a tripartite structure consisting of: (1) a fibrillar center, (2) a compact granular portion, and (3) a reticular portion containing both pars fibrosa and pars granulosa. The nucleoli of primary spermatocytes showed a developed reticular portion. At pachytene, the compact granular portion enlarged and lost its connection with the fibrillar center and the reticular portion which decreased in size. This suggests a nucleolar segregation similar to that of ovocytes in many species. Two similar developmental stages of nucleoli were observed in spermatogonia. In addition to nucleoli, there were other ribonucleoprotein-containing structures such as intranuclear closely-packed granules in Ap spermatogonia, coarse granules in the chromatin rarefaction zone of Ad spermatogonia, the nuage and Lubarsch crystals of spermatogonia, the chromatoid body of spermatids, the annulate lamellae of both spermatids and Sertoli cells, and many structures of the spermatid neck region.This work was supported by a grant from the Comisión Asesora de Investigación Científica y Técnica, Madrid, Spain     

Active Immunization Against Gonadotropin-Releasing Hormone Combined With Androgen Supplementation Is a Promising Antifertility Vaccine for Males

ABSTRACT: Male rats and rabbits were immunized against gonadotropin-releasing hormone (GnRH) conjugated to tetanus toxoid (GnRH-TT) using only materials approved for humans. Testosterone (T)-releasing implants or the long-lasting T ester testosterone-17-trans-4-n-butyl-cyclohexane carboxylate (TE) was used as supplemental androgen for maintaining libido. Immunization against GnRH-TT effectively suppressed fertility (spermatogenesis) in rats and rabbits. Neither T nor TE administration restored fertility. Both androgens were effective in maintaining normal libido in rats. TE, which is not hydrolyzed in rabbits, was less effective in maintaining normal ejaculatory behavior in this species. Active immunization against GnRH could be a convenient and cost-effective method of fertility control in males.     

大鼠睾丸发育过程基因表达的研究

本研究选取１、３ 和８（成年）周龄等不同发育阶段大鼠,应用睾丸组织树脂包埋形态学观察与ｍ ＲＮＡ 差异显示逆转录－聚合酶链反应技术（ｄｉｆｆｅｒｅｎｔｉａｌｄｉｓｐｌａｙ ＲＴ－ＰＣＲ,ＤＤＲＴ－ＰＣＲ）相结合,探讨大鼠睾丸发育过程中,精子发生过程睾丸特异基因的表达。结果：对不同周龄大鼠睾丸ｍ ＲＮＡ 进行差异比较,共得到 ８２ 个ｃＤＮＡ 差异片段。又分别标记不同周龄大鼠睾丸全部 ｍ ＲＮＡ 为探针,对其中 ４０ 个ｃＤＮＡ差异片段进行斑点杂交,得到１２ 个初步鉴定的特异或表达增加的ｃＤＮＡ 差异片段,片段范围２５０～５００ ｂｐ,其中２ 个在１ 周龄睾丸组获得,４ 个在３ 周龄睾丸组获得,在８ 周龄组获得 ５ 个,一个为１ 周和３ 周龄共有而８ 周龄大鼠缺乏的ｃＤＮＡ 片段。通过形态学观察与ｍ ＲＮＡ 差异显示的结果对应分析,初步认为２ 个１ 周龄的特异基因片段属于睾丸二倍染色体生精细胞表达基因,４ 个３ 周龄睾丸特异基因片段也属二倍或四倍体生精细胞表达基因,其中Ｂ型精原细胞和初级精母细胞的表达基因占主要成分;而成年动物的５ 个特异基因片段是属单倍体的精子细胞以及减数分裂过程的精母细胞表达基因片段     

Toxic effects of Carthamus tinctorius L. (Safflower) extract on mouse spermatogenesis

Objective

To evaluate the effects of aqueous extract of Carthamus tinctorius L., also named safflower, on mouse spermatogenesis.

Methods

Sixteen adult male NMRI mice were used. Experimental group received Carthamus tinctorius L. extract at the dose of 200 mg/kg for 35 consecutive days and control group received only distilled water. Testicular histopathology, morphometric analysis and spermatogenesis assessments were performed for evaluation of the Carthamus tinctorius L. extract effects on testis.

Results

Histopathological criteria such as epithelial vacuolization, sloughing of germ and detachment were significantly decreased in Carthamus tinctorius L. treated mice (p < 0.001). Carthamus tinctorius L. extract induced formation of multinucleated giant cells in the germinal epithelium. Carthamus tinctorius L. extract also caused a significant decrease in seminiferous tubule diameter, seminiferous epithelium height and maturation arrest (p < 0.001).

Conclusion

Carthamus tinctorius L. extract has toxic effects on mouse testicular tissue, and recommended to use it with caution if there is a reproductive problem.     

SEPT11基因在小鼠睾丸精子发生过程中的表达特征

目的初步探讨Septin11(SEPT11)基因在精子发生中的作用。方法通过实时定量PCR、蛋白免疫印迹及免疫荧光等方法检测SEPT11在不同周龄野生型小鼠以及成年睾丸支持细胞激素受体(Ar)特异性敲除小鼠(SCARKO)和Ar全敲除(ARKO)小鼠睾丸中的表达特征。结果 SEPT11基因小鼠出生2周内高表达,随后表达水平降低,出生6周后出现并与未释放的成熟精子共定位且高表达。与野生型小鼠相比,SEPTIN11在SCARKO小鼠和ARKO小鼠睾丸中表达降低(P0.01),m RNA水平显著升高(P0.01);SEPTIN11在成熟精子中定位于尾部。结论 SEPT11基因在小鼠出生时表达最高;SEPTIN11在小鼠成熟精子中定位于尾部;Ar的敲减提高了SEPT11的表达。     

SERUM INHIBIN B AS A MARKER FOR SPERMATOGENESIS

This study was conducted to evaluate the expression of transforming growth factor- &;#103 1 (TGF- &;#103 1) in testis with aging and progress of diabetes mellitus (DM) and correlated this with testicular function. Zucker diabetic fatty rats (15, 40, and 75 weeks old) were used as models for non-insulin-dependent DM. The controls were age-matched nondiabetic Zucker fatty rats. Serum testosterone levels and daily sperm production were evaluated. Testicular tissue was immunostained with anti-TGF- &;#103 1. Labeled cells were assessed and the staining intensity was estimated. The 15-week control and diabetic animals showed the lowest levels of staining intensity but this started to increase significantly in the older animals of both categories. However, the diabetic animals had significantly deeper intensities relative to controls at the different age groups. These changes in TGF- &;#103 1 expression were negatively correlated with both testosterone and sperm production. Therefore, aging and DM enhanced the expression of TGF- &;#103 1 in testis, and this was parallel with progress of both conditions, although DM seems to be predominant. These alterations in TGF- &;#103 1 expression may be related to changes in testicular function associated with both conditions.     

ADENOVIRUS-MEDIATED p53 GENE TRANSFER TO RAT TESTIS IMPAIRS SPERMATOGENESIS

The aim of this study was to evaluate postoperative changes in sperm chromatin heterogeneity in varicocele patients. In 15 infertile patients with varicocele, sperm parameters including concentration, motility, and morphology were evaluated before and after surgical correction of varicocele. Sperm motion analysis using computer-assisted semen analyzer (CASA) was also performed. To analyze the sperm nuclear proteins, the acridine orange staining method was used. On semen analysis, sperm concentration and motility significantly increased after surgery (p = 0.002, p = 0.003, respectively), although sperm morphology was unaltered postoperatively. CASA parameters, including velocity, linearity, amplitude of lateral head displacement and beat cross frequency were unaltered postoperatively. On the other hand, acridine orange staining significantly increased postoperatively (p = 0.002). Varicocele influences the sperm chromatin condition, as well as sperm concentration and motility.