Disruption of ectoplasmic specializations between Sertoli cells and maturing spermatids by anti-nectin-2 and anti-nectin-3 antibodies

AIM: To understand the biological functions of the ectoplasmic specializations between Sertoli cells and maturing spermatids in seminiferous epithelia. METHODS: In order to disrupt the function of the ectoplasmic specializations, nectin-2, which is expressed at the specialization, was neutralized with anti-nectin-2 antibody micro-injected into the lumen of the mouse seminiferous tubule. Anti-nectin-3 antibody was also micro-injected into the lumen in order to neutralize nectin-3, which is expressed at the specialization. RESULTS: The actin filaments at the specialization disappeared, and exfoliation of maturing spermatids was observed by electron microscopy. CONCLUSION: Nectin-2 was neutralized by anti-nectin-2 antibody and nectin-3 was neutralized by anti-nectin-3 antibody, respectively. Inactivated nectin-2 and nectin-3 disrupted the nectin-afadin-actin system, and finally the actin filaments disappeared. As a result, the specialization lost the holding function and detachment of spermatids was observed. One of the functions of the specialization seems to be to hold maturing spermatids until spermiation.     

Determination of Sertoli cell numbers in the developing rat testis by stereological methods

Stereological studies were performed to determine the number of Sertoli cells present during the postnatal development of the rat testes. Sprague-Dawley rats aged from 1 to 70 days were used in two experiments, and in each were fixed by vascular perfusion and embedded in Epon-Araldite, subsequent to which 1 micron sections stained with Toluidine blue were prepared. In the first experiment, rats aged from 1 to 20 days were used in groups of three, and number estimates were made using a direct counting method. In the second, which used groups of four rats aged from 20 to 70 days, a point sampled intercept was used to estimate nuclear volume and thence number. The results of the experiments indicate that the newborn rat testis contains 1.3 +/- 0.2 x 10(6) Sertoli cells and that this number increases to 38.4 +/- 2.7 x 10(6) at day 15. No further increase in Sertoli cell number occurred thereafter up to day 70 of age.     

Hormonal Regulation of Sertoli Cells

The Sertoli cell is the primary target within the testis for both FSH and androgens. FSH binds to cell surface receptors, alters cyclic nucleotide metabolism and affects Ca⁺⁺ flux. Cyclic AMP and Ca⁺⁺, via an intracellular receptor protein, the calcium-dependent regulator (CDR), control the cytoskeletal network which is comprised of microtubules and microfilaments. By affecting these intracellular components FSH regulates specific protein secretion and cell motility. In addition FSH results in an overall stimulation of protein synthesis and specifically modulates the levels of at least two intracellular regulatory proteins. Androgens bind to a specific cytoplasmic receptor which is translocated into the nucleus of interphase cells. This class of steroids is also involved in androgen binding protein metabolism but the precise mechanism of control is unknown. The interrelationships of FSH and androgen in the control of spermatogenesis is discussed. In addition, consideration is given to the possible development of male contraceptive by interfering with various steps in the mechanism of action of peptide and steroid hormones upon the Sertoli cell.     

Sertoli细胞诱导大鼠肝内胰岛移植物免疫豁免的实验研究

目的 探究睾丸Sertoli细胞能否对肝内共移植的胰岛移植物提供免疫豁免作用以及共移植的睾丸Sertoli细胞最佳数量。方法将同种大鼠胰岛及不同数量的睾丸Sertoli细胞同时移植于糖尿病受体的肝内,观察移植物存活情况、胰岛功能、并检测移植物内胰岛素和Fas配体(FasL)表达以及浸润淋巴细胞凋亡情况。结果单纯胰岛移植组平均存活期为(5.6±0.8)d,同时与胰岛细胞在肝内共移植的睾丸细胞数增加至1×107个时,平均存活期为(41.4±4.61)d,明显延长(P<0.05),胰岛移植物中有大量表达FasL的睾丸细胞和表达胰岛素的胰岛细胞.在移植物周围有大量浸润的淋巴细胞凋亡。结论睾丸Sertoli细胞与胰岛细胞同时在肝内共移植,通过诱导局部豁免而延长胰岛移植物的存活时间,且同时共移植1×107个Sertoli细胞时效果最好。     

Cytokines produced by microwave-radiated Sertoli cells interfere with spermatogenesis in rat testis

Microwave radiation resulted in degeneration, apoptosis or necrosis in germ cells at different stages. The molecular mechanisms by which microwaves induce spermatogenesis disorder have not been completely understood. Sertoli cells play crucial roles in mammalian spermatogenesis. Cytokines produced by Sertoli cells play pleiotropic roles in different conditions. At physiologically low concentration, TNFα, IL-1β and IL-6 behave as survival factors; while under pathological condition, these cytokines can induce apoptosis in testis. The effects of cytokines produced by microwave-radiated Sertoli cells on spermatogenesis are poorly understood. The purpose of this study was to determine the effect of cytokines produced by microwave-radiated Sertoli cells on the germ cells. We focused the effect of TNFα, IL-1β and IL-6 on the germ cells. The results showed that TNFα, IL-1β and IL-6 were increased in Sertoli cells after exposure to microwave radiation. These up-regulated cytokines can induce apoptosis and lipid peroxidation in the membrane of germ cells. In addition, germ cell apoptosis was associated with the up-regulation of Bax/Bcl-2 and caspase-3. These results suggest that cytokines produced by microwave-radiated Sertoli cells may disrupt spermatogenesis. Our data provided novel insight into the injury mechanism of germ cells induced by microwave radiation.     

Ezrin: a regulator of actin microfilaments in cell junctions of the rat testis

Ezrin, radixin, moesin and merlin (ERM) proteins are highly homologous actin-binding proteins that share extensive sequence similarity with each other. These proteins tether integral membrane proteins and their cytoplasmic peripheral proteins (e.g., adaptors, nonreceptor protein kinases and phosphatases) to the microfilaments of actin-based cytoskeleton. Thus, these proteins are crucial to confer integrity of the apical membrane domain and its associated junctional complex, namely the tight junction and the adherens junction. Since ectoplasmic specialization (ES) is an F-actin-rich testis-specific anchoring junction-a highly dynamic ultrastructure in the seminiferous epithelium due to continuous transport of germ cells, in particular spermatids, across the epithelium during the epithelial cycle-it is conceivable that ERM proteins are playing an active role in these events. Although these proteins were first reported almost 25 years and have since been extensively studied in multiple epithelia/endothelia, few reports are found in the literature to examine their role in the actin filament bundles at the ES. Studies have shown that ezrin is also a constituent protein of the actin-based tunneling nanotubes (TNT) also known as intercellular bridges, which are transient cytoplasmic tubular ultrastructures that transport signals, molecules and even organelles between adjacent and distant cells in an epithelium to coordinate cell events that occur across an epithelium. Herein, we critically evaluate recent data on ERM in light of recent findings in the field in particular ezrin regarding its role in actin dynamics at the ES in the testis, illustrating additional studies are warranted to examine its physiological significance in spermatogenesis.     

Endocrine Profile of 45 Patients with Sertoli Cell Only Syndrome

Endokrines Profil bei 45 Männern mit Sertoli-Zell-Syndrom
Bei 45 Männern mit Sertoli-Zell-Syndrom wurden die Hormonbasiswerte für FSH, LH, Prolaktin und Testosteron mit denen von Klinefelter-Paitenten, Männern mit Oligozoospermie und gesunden, fertilen Männern verglichen. Dabei ergab sich, daß die FSH- und LH-Werte bei Sertoli-Zell-Syndrom signifikant höher lagen als bei Gesunden. Die Erhöhung der Gonadotropine bei Patienten mit Sertoli-Zell-Syndrom was allerdings nicht so hoch und Testosteron nicht so herabgesetzt wie man es bei Klinefelter-Paitenten gefunden hatte. Aus dem Resultat, daß die LH-Werte erhöhte waren, während Testosteron sich im normalen Rahmen bewegte wird die Schlußfolgerung gezogen, daß hier eine kompensierte Dysfunktion der Leydigzellen bei den Patienten mit Sertoli-Zell-Syndrom vorliegt. Für Oligozoo-spermie-Patienten ließ sich keine Differenz der Hormonwerte gegenüber Gesunden feststellen.     

胰岛素替代治疗对青春期糖尿病鼠睾丸间质和支持细胞功能的影响

以４０日龄雄性Ｗｉｓｔａｒ大鼠４０只，分为对照（Ｃ），糖尿病（Ｄ），糖尿病胰岛素及时治疗（ＤＣＩＲ）和糖尿病胰岛素延迟治疗（ＤＤＩＲ）组，进行睾丸间质细胞和支持细胞功能的研究。结果表明：血清睾酮Ｄ组最低，培养间质细胞睾酮分泌量ＤＣＩＲ、ＤＤＩＲ和Ｄ组均显著低于Ｃ组（Ｐ＜０．０５及０．００１），ｃＡＭＰ分泌量ＤＤＩＲ和Ｄ组显著低于Ｃ和Ｄ分别的ＣＩＲ组（Ｐ＜０．０１）；睾丸组织雄激素结合蛋白（ＡＢＰ）水平，ＤＤＩＲ组显著高于Ｃ和Ｄ组（分别为Ｐ＜０．０５及Ｐ＜０．０１），其它组间比较差异不显著，培养支持细胞ＡＢＰ分泌量Ｄ组显著低于Ｃ和ＤＣＩＲ组（Ｐ＜０．０５），ｃＡＭＰ分泌量ＤＤＩＲ和Ｄ组显著低于Ｃ和ＤＣＩＲ组（Ｐ＜０．０１）。     

Sertoli细胞与成人胰岛细胞共同培养的研究

目的观察塞尔托利（Sertoli）细胞对体外培养的成人胰岛细胞形态、存活率及功能的影响。方法胰腺、睾丸取自志愿捐赠的成年男性尸体多器官供者,共12例。分离纯化后的成人胰岛细胞分为单独培养组和共同培养组,单独培养组取成人胰岛细胞单独培养,共同培养组为成人胰岛细胞＋Sertoli细胞共同培养,均在RPMI1640培养液培养14d,采用倒置相差显微镜观察胰岛细胞形态,比较两组的胰岛细胞存活率、胰岛素分泌量和胰岛素刺激指数。结果培养14d后,共同培养组胰岛细胞存活率为（90±3）%,较单独培养组的（57±4）%明显提高（P〈0.01）,胰岛细胞的形态亦较单独培养组完整。共同培养组胰岛细胞始终对葡萄糖刺激保持较高的敏感度,而单独培养组胰岛细胞对葡萄糖刺激的敏感度随时间的延长明显降低（P〈0.05）。培养14d后,共同培养组的胰岛素分泌量为（249±12）mIU/L、胰岛素刺激指数为8.15±0.64,而单独培养组则分别为（47±7）mIU/L和1.68±0.34,两组比较差异有统计学意义（均为P〈0.01）。结论成人胰岛细胞与Sertoli细胞共同培养可以提高胰岛细胞的存活率,改善胰岛细胞的功能。     

大鼠睾丸支持细胞溶酶体的周期性变化

作者在透射电镜下观察了大鼠精子发生过程中支持细胞（Ｓｅｒｔｏｌｉ细胞）中溶酶体的结构及分布的改变。结果Ｓｅｒｔｏｌｉ细胞中溶酶体数目多，在细胞中所处的位置有周期性变化，细胞中全部胞质和在基底部胞质中溶酶体的截面积占胞质截面积的比例在生精第ＶＩＩ阶段最大，近腔部溶酶体截面积占胞质截面积在第ＩＩ、ＩＸ阶段最小；Ｓｅｒｔｏｌｉ细胞总胞质和在基底部单位胞质截面积的溶酶体数在第ＶＩＩ阶段最大，近腔部单位胞质截面积溶酶体数在顶体期后几阶段最大，第ＩＸ阶段最小。Ｓｅｒｔｏｌｉ细胞溶酶体的周期性变化是与生精细胞相互影响、相互作用，也是精子连续正常发生的前提条件之一。     

Sertoli cell tumor of the testis: a case with late metastasis

We report on a 20-year-old male who underwent a radical orchidectomy when he was 12 years old which revealed a Sertoli cell tumor in his right testis, and who presented with a 5 × 3 cm retroperitoneal metastatic mass 8 years after orchidectomy. Current experience on Sertoli cell tumor of the testis (SCTT) is insufficient to prognosticate the clinical behavior of the primary tumor on the long term. Case reports in the literature on patients with late metastases suggest a very long followup after orchidectomy may be required.     

Selected Enzyme Histochemistry of Sertoli Cells 1. Immature Rat Sertoli Cells in Vitro

Sertoli cells were collected from the testes of 21 day old, sexually immature Wistar rats. The cells were then incubated for 10 or 14 days in culture medium with or without the addition of FSH. This time period corresponds to the time period in vivo when rat Sertoli cells undergo active differentiation with concomitant histochemical and morphological changes. Cells cultured 10 and 14 days after initial plating were processed for the histochemical detection of three esterases and four dehydrogenases by observing relative staining intensities of azo dye precipitation and formazan reaction product, respectively. Appropriate controls were established. The presence of FSH mildly increased the staining activity of LDH, SDH and G-6-PDH in both 10 and 14 day cultured cells. However, SDH staining intensity/cell did not increase to surpass LDH staining intensity/cell as it does in vivo during this period of time. Addition of FSH also slightly increased staining of non-specific esterase. Type B esterase and 3 beta-ol DH activity was not evident in 10 and 14 day cultured cells, even in the presence of FSH. Our results indicate that, based on histochemical parameters, immature Sertoli cells do not mature in culture commensurate with the cell in vivo.     

Sertoli cell tumor (gonadal stromal tumor) in an infant.

An 8-mo-old boy had an orchiectomy for a Sertoli cell tumor. Malignancy was suspected histologically. He underwent a retroperitoneal lymphadenectomy and no nodes contained metastases. The histologic criteria for malignancy in Sertoli cell tumors are controversial. Individual case reports of patients with these tumors are encouraged to help establish their natural history and optimum management.     

Case report: Malignant Sertoli cell tumor of the testis in an adult

International Urology and Nephrology -     

不同温度下体外大鼠睾丸支持细胞胶质细胞源性神经生长因子的表达

目的:通过观察不同温度下体外大鼠睾丸支持细胞(Sertoli cell,SC)胶质细胞源性神经生长因子(GDNF)表达特点,探讨高温致不育的机制。方法:采用组合酶消化法和选择性贴壁法分离雄性Wistar大鼠睾丸SC,将分离的SC分别置于不同温度进行体外培养,观察其贴壁、形态学变化,FasL免疫组化鉴定。实验分为对照组(35℃)、实验组(36℃、37℃、38℃、39℃)。CCK-8法检测SC增殖情况,HE染色观察细胞形态及结构,RTPCR、免疫荧光及Western印迹检测细胞GDNF的表达。结果:本实验条件下,体外分离培养SC纯度=(95.30±2.15)%(n=10),CCK-8实验结果显示,36℃时细胞增殖率最高(P0.01),36℃时,随着温度的提高,增殖率逐渐降低,39℃对细胞增殖具有明显抑制作用(P0.01);免疫荧光结果显示,GDNF表达于SC胞质,36℃时荧光最强,RT-PCR及Western印迹检测结果显示,高于36℃时,GDNF mRNA及蛋白的表达随着温度的增加而降低,36℃、37℃、38℃、39℃4组与对照组比较,差异均有统计学意义(P0.05)。结论:不同温度下,体外培养SC的增殖能力和GDNF表达明显不同。36℃时,随着温度的提高,增殖能力受到抑制,GDNF表达水平显著降低。本研究结果证实,高温下大鼠睾丸SC正常功能受到抑制,从而影响生精功能。     

The morphology of the human undescended testis with special reference to the Sertoli cell and puberty

The morphology of the undescended testis was studied in 50 boys aged 1-15 years. A low mean number of spermatogonia was found, but there were marked differences between the boys, some having high numbers whereas others were devoid of spermatogonia. Most Sertoli cells did not undergo normal maturation during puberty, but instead seemed to proliferate at a slow rate. It is concluded that treatment of undescended testes should be performed during the prepubertal period. It is also suggested that some undescended testes have a primary defect whereas others are damaged during the onset of puberty.     

Involvement of apoptosis in the control of Sertoli and pre-meiotic germ cell numbers in the developing rabbit testis

The numbers of Sertoli and pre-meiotic germ cells in the developing rabbit testis were investigated as an initial step in determining the physiological meaning of the control of cell number in the testis by apoptosis. Sections were stained immunohistochemically for the detection of apoptotic cells and counterstained with haematoxylin. The number resulting from subtraction of the number of apoptotic cells from the total cell number was defined as the viable cell number. The number of viable premeiotic germ cells in the adluminal compartment of seminiferous tubules decreased during the pre-natal period, although neither apoptotic nor necrotic figures were detected. After birth, the numbers of total and apoptotic Sertoli and pre-meiotic germ cells increased, maintaining a stable ratio of their viable cell populations until the induction of meiosis. During induction of meiosis, the increase in the number of viable Sertoli cells was significantly accelerated because of the rapid decrease in the number of apoptotic Sertoli cells. Just after spermatids were formed the number of viable spermatogonia increased, reflecting an active supply of differentiated sper matogonia entering meiosis. In conclusion, apoptosis of Sertoli and pre-meiotic germ cells plays an important role in the acquisition of a suitable ratio of both cell types, and in providing intratubular environments for further progression of spermatogenesis, by controlling numbers of both cell types during the post-natal period.     

睾丸大细胞钙化型支持细胞瘤临床病理观察

目的:探讨睾丸大细胞钙化型支持细胞瘤的临床及病理组织学特征。方法:运用组织学、免疫组化及组织化学技术对1例睾丸大细胞钙化型支持细胞瘤进行光镜观察及免疫标记,并结合相关文献对其临床表现、组织形态、免疫组化特点及治疗和预后等进行分析。结果:患者为青年男性,病理组织学表现为肿瘤细胞排列成巢状、梁状,细胞呈多角形,胞质嗜酸,核大空泡状,伴间质广泛钙化。免疫组化染色显示肿瘤细胞inh ib in(+)、S-100(+)和vim entin(+),PLAP(-)、SMA(-)、CK(-)、AFP(-)。组织化学染色阿辛蓝(+)、过碘酸雪夫氏反应(PAS)阴性。结论:大细胞钙化型支持细胞瘤是一种罕见的睾丸性索间质肿瘤;免疫组化有助于睾丸大细胞钙化型支持细胞瘤的诊断,鉴别诊断包括精原细胞瘤的管状型、睾丸间质细胞瘤(Leyd ig细胞瘤)、普通型及硬化型支持细胞瘤、雄激素不敏感综合征以及隐睾中的支持细胞结节等,手术切除预后良好。     

Early signs of Sertoli and Leydig cell dysfunction in the abdominal testes of immature unilaterally cryptorchid rats

Testicular descent was prevented unilaterally by cutting the gubernaculum testis of newborn rats. When 20 days old unilaterally cryptorchid rats were injected intraperitoneally with 2 μg bFSH per gram body weight and killed 6 h later when testicular testosterone (T) and oestradiol (E₂) concentrations were determined. The increase in E₂ was subnormal in abdominal testes. In 18-day-old unilaterally cryptorchid rats the efferent ducts were ligated bilaterally, and the rats were killed 48 h later. The weight increase, due to accumulation of seminiferous tubule fluid, was significantly greater in the abdominal testes. In contrast, the ABP content of the abdominal epididymis was subnormal in 20-day-old unilaterally cryptorchid rats. Unilateral orchidectomy was performed in 16-day-old unilaterally cryptorchid rats and at 20 days of age intratesticular T and E₂, and plasma FSH and LH concentrations were determined and compared to that in 20-day-old control unilaterally cryptorchid rats. Removal of an abdominal testis resulted in increased plasma FSH and intratesticular E₂, whereas plasma levels of LH and intratesticular levels of T were unaffected. Removal of a scrotal testis resulted in increased plasma FSH and LH coupled with increased intratesticular T and E₂. Rats with a single abdominal testis had higher plasma FSH and LH and intratesticular T, but similar intratesticular E₂, than rats with a single scrotal testis. It is concluded that Sertoli and Leydig cell function are influenced by cryptorchidism at a stage when the temperature difference, and the morphological differences between the testes are very discrete.     

Sertoli cell — Leydig cell interaction in the regulation of testicular function

Considerable evidence exists to indicate that the Leydig cells influence the seminiferous tubule by maintaining a high concentration of testosterone in the peritubular compartment of the testes. Recent studies using various types of agents to disrupt spermatogenesis, have shown that significant changes occur in the structure and function of the Leydig cells. In these situations, Leydig cells enlarge, show hyperresponsiveness to hCG stimulation in vitro and contain a reduced number of receptors for LH/hCG. Evidence is presented to support the hypothesis that the changes in Leydig cell structure and function are the result of local factors. The data provide support for the concept that the functioning of Leydig cells is modulated by the seminiferous tubules.