大鼠睾丸扭转后生殖细胞凋亡与Bcl-2和Bax基因表达

目的 :研究睾丸扭转复位后生殖细胞凋亡与Bcl 2 /Bax基因表达的关系。　方法 :30只成年健康SD雄性大鼠随机分成扭转组 (n =15 )和对照组 (n =15 )。建立单侧睾丸扭转复位动物模型 (72 0° 2h)。术后 3d取手术侧睾丸 ,采用原位缺口末端标记法 (TUNEL)检测生殖细胞凋亡 ,免疫组化SP法检测Bcl 2 /Bax基因表达。　结果 :与对照组相比 ,扭转组手术侧睾丸生殖细胞凋亡显著增多 (P <0 .0 1) ,Bax表达显著升高 (P <0 .0 1) ,Bcl 2表达显著降低 (P <0 .0 1)。凋亡细胞主要是初级精母细胞和圆形精子细胞。　结论 :睾丸扭转复位后 ,生殖细胞凋亡与Bcl 2 /Bax基因表达密切相关。细胞内Bcl 2 /Bax比值是影响生殖细胞凋亡的重要因素之一。     

大鼠睾丸扭转生殖细胞凋亡与抗氧化酶和Bcl-2基因表达的关系

目的　探讨睾丸扭转复位后生殖细胞凋亡及其发生机制。方法　建立单侧睾丸扭转复位大鼠模型(72 0° ,2h)。术后 72小时取手术侧睾丸 ,采用TUNEL法检测生殖细胞凋亡 ,免疫组化SP法检测Bcl 2基因表达 ,并测定睾丸组织中超氧化物歧化酶 (SOD)和过氧化氢酶 (CAT)活性。结果　实验组手术侧睾丸生殖细胞凋亡增多 ,Bcl 2基因低表达 ,SOD和CAT活性下降 ,与对照组相比 ,两组差别具有极显著性意义 (P <0 .0 1)。结论　睾丸扭转复位后生殖细胞凋亡增多与Bcl 2基因低表达和抗氧化酶活性下降有关。     

荧光定量聚合酶链反应检测去颌下腺大鼠睾丸Bcl 2和Bax mRNA的改变

目的观察切除颌下腺对大鼠睾丸Bax和Bcl 2 mRNA表达的影响。方法切除大鼠颌下腺,分别于术后14、28和42 d处死大鼠,提取睾丸总RNA,反转录,设计特异性引物和Taqman探针,荧光定量聚合酶链反应(PCR)检测Bax和Bcl 2 mRNA的改变。结果随着颌下腺切除时间的延长,实验组大鼠睾丸Bax和Bcl 2 mRNA的比值显著升高,与对照组比较,有显著性差异(P<0.01)。结论颌下腺切除大鼠睾丸Bax和Bcl 2 mRNA比值明显升高,提示颌下腺切除所致的大鼠睾丸生精细胞的凋亡可能是由Bax和Bcl 2介导的线粒体途径进行,但Fas/FasL是否参与该凋亡过程还有待进一步研究。     

维拉帕米对c-jun调节睾丸间质细胞睾酮分泌的影响

目的通过c-jun反义寡脱氧核苷酸(ASODNs)观察c-jun在调节人绒毛膜促性腺激素(hCG)诱导的睾丸间质细胞(LC)睾酮(T)分泌的作用。方法采用c-jun ASODNs拮抗c-jun,维拉帕米阻断钙通道,hCG诱导体外培养大鼠LC的T分泌,放射免疫方法检测T水平。结果c-jun ASODNs(0~2μmol/L)呈剂量依赖性抑制hCG诱导的离体LC的T分泌(P<0.01)。维拉帕米(10-5mol/L)可加强c-jun ASODNs抑制T分泌。结论c-jun促进hCG诱导大鼠LC的T分泌,c-jun表达可能与钙离子相关。     

睾丸支持细胞与生精细胞凋亡的关系

生精细胞处于支持细胞构造的环境中 ,激素、生长因子和温度以及它们与支持细胞的联系调控着生精细胞的分化与成熟 ;细胞之间的旁分泌信号转导亦调节着生精细胞凋亡的过程。在睾丸生精细胞发生的自发性凋亡和诱发性凋亡中 ,支持细胞表达和分泌的产物扮演重要角色。     

精索静脉曲张大鼠睾丸自噬对生精细胞的影响

目的:研究精索静脉曲张(VC)大鼠模型中睾丸不同水平自噬对生精细胞凋亡的影响。方法:雄性SD大鼠54只随机分为6组:空白对照组、雷帕霉素对照组、氯喹对照组各6只,VC组、VC+雷帕霉素组、VC+氯喹组各12只。采用HE染色观察睾丸、附睾组织形态学变化,并对睾丸及附睾中精子形成情况进行评分,TUNEL染色检测生精细胞凋亡指数(AI),Western印迹检测LC3、p62、Bax、Bcl-2的表达。结果:空白对照组、雷帕霉素对照组、氯喹对照组大鼠睾丸及附睾组织均未发生明显形态学变化,精子形成情况评分及AI亦无显著差异(P>0.05);VC组大鼠睾丸及附睾组织发生明显病理损伤,精子形成情况评分显著降低(P<0.01),AI显著升高(P<0.01),但VC+雷帕霉素组较VC组明显改善,而VC+氯喹组较VC组轻度加重。此外,与空白对照组比较,VC组自噬相关蛋白LC3(包括LC3-Ⅱ/LC3-Ⅰ的比值)和促凋亡蛋白Bax表达显著增加(P<0.01),抑凋亡蛋白Bcl-2表达则显著降低(P<0.01);且VC+雷帕霉素组LC3与Bcl-2表达显著高于VC组(P<0.01),p62和Bax表达则显著低于VC组(P<0.01);而VC+氯喹组LC3与Bcl-2表达显著低于VC组(P<0.01),p62和Bax的表达则显著高于VC组(P<0.01)。结论:VC可诱导大鼠睾丸自噬和生精细胞凋亡,上调自噬可抑制生精细胞凋亡,阻滞自噬则可促进生精细胞凋亡。     

激素对精子发生的调控

精子发生是一个连续不断的细胞增生与分化的过程 ,是激素依赖的调控 ,其中卵泡刺激素 (FSH)和黄体生成素 (LH)刺激释放的睾酮 (T)是主要的激素调节者。睾丸内T是维持精子发生最关健的因素之一 ,而FSH对正常精子发生的起始和维持同样是必须的。在介导激素调节中 ,Sertoli细胞处于核心地位。同时 ,正常精子发生过程中的生精细胞凋亡也是激素调控的。深入研究精子发生的激素调控 ,为探索安全、可复的男性避孕方法奠定了基础。     

前列腺癌细胞凋亡与iNOS、Bcl-2的表达及意义

目的 :探讨细胞凋亡和诱生型一氧化氮合酶 (iNOS)、Bcl 2蛋白表达在前列腺癌中的意义以及两者之间的关系。　方法 :对 2 4例前列腺癌、15例前列腺增生及 5例正常前列腺组织行原位细胞凋亡检测及iNOS、Bcl 2蛋白免疫组化检测。　结果 :前列腺癌组的细胞凋亡率和iNOS的染色强度均显著高于前列腺增生组及正常前列腺组(P <0 .0 1) ,且Bcl 2蛋白表达阳性者的细胞凋亡率显著低于阴性者 (P <0 .0 1)。　结论 :前列腺癌的细胞凋亡率可反映其恶性程度 ;iNOS的表达与前列腺癌的分化程度无关 ,但与Bcl 2蛋白表达呈负相关 ;Bcl 2蛋白表达与前列腺癌细胞凋亡呈负相关。iNOS与Bcl 2均可通过影响前列腺癌细胞凋亡而在前列腺癌病理发生发展中起作用     

JQ1对脂多糖所致小鼠生精功能障碍的影响

目的 探讨JQ1对脂多糖(LPS)所致小鼠生精功能障碍的影响及相关机制。方法 40只8周龄雄性C57BL/6J小鼠，随机分为溶媒对照组(DMSO+NS)、模型组(DMSO+LPS)和药物干预组(JQ1+LPS),每组小鼠的数量分别为n=13、n=15和n=12,单次腹腔注射LPS诱导炎症动物模型。取材后，称量睾丸、附睾尾的重量，采用精子计数法检测小鼠精子数量，伊红染色检测精子的畸形率，苏木精-伊红(HE)染色检测睾丸形态变化；TUNEL试剂盒检测睾丸生殖细胞凋亡情况；Western blot检测凋亡基因(Bax和Bcl2)的表达情况；生化试剂盒检测睾丸丙二醛(MDA)、谷胱甘肽(GSH)和氧化型谷胱甘肽(GSSG)表达情况。结果 LPS导致小鼠附睾尾重量显著下降(P<0.05),精子数量显著下降(P<0.001);精子畸形率显著升高(P<0.01);睾丸形态结构破坏，生精小管萎缩，管腔直径变小，各级生精细胞排列紊乱，管腔内精子数量减少；睾丸中凋亡细胞数量显著上调(P<0.01);Bax/Bcl2的比值显著上升(P<0.01);MDA含量显著增加(P<...     

膀胱癌细胞Bcl-x前体mRNA剪接模式调控的研究

目的　探讨Bcl x前体mRNA在膀胱癌细胞BIU 87中的剪接模式并比较不同剪接模式的作用与凋亡效应。　方法　利用反义寡核苷酸靶击Bcl x基因下游选择性 5′端剪接点 ,将其剪接模式从Bcl xL移至Bcl xS。应用细胞增殖活性分析、逆转录聚合酶链反应、细胞周期时相分析、Westernblot和克隆形成等方法检测Bcl x前体mRNA剪接模式调控对肿瘤细胞的抑制效应。　结果　当反义寡核苷酸 (AS)浓度为 1.6 μmol/L时 ,转染后 72h细胞生长抑制率分别为 5 8.2 % ( 5′ Bcl xAS)和 32 .5 % ( 3′ Bcl xAS) ,其抑制效应呈浓度和时间依赖性 ,抑制效应在治疗后 12h开始出现 ,72h达到高峰 ;S期细胞比例显著下降 ,G1期细胞比例上升 ;克隆形成率降低。 5′ Bcl xAS组Bcl xLmRNA和蛋白质表达降低 ,Bcl xSmRNA和蛋白质表达增高。剪接模式Bcl xS( 5′ Bcl xAS)调控诱导的凋亡效应大约 2倍于Bcl xL( 3′ Bcl xAS)调控模式。　结论　膀胱癌细胞BIU 87中Bcl x前体mRNA剪接模式对肿瘤细胞的抑制作用优于Bcl x剪接模式     

环境污染物三丁基氯化锡和氯化三苯锡对大鼠睾丸Leydig细胞的影响

目的:探讨环境污染物三丁基氯化锡(TBT)和氯化三苯锡(TPT)对大鼠睾丸Leyd ig细胞的影响。方法:①用0~80 nmol/L浓度的TBT和TPT处理大鼠睾丸Leyd ig(LC-540)细胞24~96 h,用四唑蓝(MTT)法确定细胞的存活率;②用DNA片段法确定是否存在细胞凋亡;③观察细胞内Ca2+螯合剂氨基苯乙烷四乙酸(BAPTA)和蛋白激酶A(PKA)抑制剂H-89、蛋白激酶C(PKC)抑制剂GF109203X、酪氨酸蛋白激酶(TPK)抑制剂Gen iste in是否可以阻断TBT所致的细胞凋亡;④检测TBT处理的原代大鼠睾丸Leyd ig细胞分泌睾酮的变化。结果:①TBT和TPT影响Leyd ig细胞存活率的强度基本相同,在20~80 nmol/L浓度时细胞存活率呈剂量和时间依赖性降低;②DNA片段法研究证实TBT和TPT可引起细胞凋亡;③BAPTA可阻断20 nmol/L的TBT所致的细胞凋亡,而PKA、PKC和TPK抑制剂对细胞存活率没有影响;④TBT可减少Leyd ig细胞分泌睾酮,并使其对人绒毛膜促性腺激素(hCG)刺激的反应性降低。结论:环境污染物TBT和TPT能直接导致睾丸Leyd ig细胞凋亡,并抑制睾酮分泌,这种致凋亡作用可能与细胞内Ca2+浓度增加有关。     

皮质酮诱导青春期大鼠睾丸间质细胞凋亡的研究

本研究目的旨在观察皮质酮能否诱导青春期大鼠睾丸间质细胞凋亡,用皮质酮分别经体内、外途径处理大鼠睾丸间质细胞。凋亡细胞经碘化丙碇（ＰＩ）标记后用流式细胞仪检测。体外研究结果表明,经１００ｎＭ皮质酮处理２４小时后的睾丸间质细胞,其凋亡量（３６．５％）显著高于对照组（１２．７％。Ｐ〈０．０１）。在体研究得到类似结果,经皮质酮（２．５ｍｇ／１００ｇ体重）处理２４小时后的大鼠,其纯化的睾丸间质细胞调亡量（２     

Taurine ameliorates cytotoxic effects of Di(2-ethylhexyl) phthalate on Leydig cells

It has been revealed that di(2-ethylhexyl)phthalate (DEHP) has toxic impacts on the male reproductive system. Taurine (TAU) is an amino acid with antioxidant property and beneficial impacts on the male reproductive system. In this study, protective impacts of Taurine (TAU) on DEHP-induced Leydig TM3 cell toxicity were investigated. The cells exposed to DEHP (0.8 µmol) or TAU (100 mg/ml) for 24 hr. Cell viability (MTT assay), apoptosis, oxidative stress and testosterone level were examined. DEHP could significantly decrease the cell viability percentage, reduce testosterone level, increase apoptosis, elevate Bax/ Bcl-2 ratio and enhance caspase-3 and -9 activity in the TM3 cells. Additionally, DEHP significantly elevated malondialdehyde contents and reactive oxygen species levels. It also augmented superoxide dismutase and catalase activity in the Leydig cells. Co-treatment of DEHP with TAU increased viability and testosterone level, while oxidative stress and apoptosis significantly reduced. TAU could decrease Bax/Bcl-2 ratio and caspase-3 and -9 activity in the DEHP-intoxicated cells. Our results have clearly shown that TAU protects TM3 cells against oxidative stress and apoptosis induced by DEHP.     

Enhancement of Leydig cell testosterone secretion by isolated seminiferous tubules during co-perifusion in vitro: comparison with static co-culture systems

The aim of this study was to identify an in-vitro test system for the reproducible demonstration of a modulatory effect of isolated seminiferous tubules (s-tubules) on testosterone production by purified rat Leydig cells. Co-incubation of s-tubules with various numbers of Leydig cells had no significant effect on basal and hCG-stimulated testosterone production over 4-24 h incubation. In contrast, addition of s-tubule conditioned medium (STCM) to Leydig cells enhanced both basal and hCG-stimulated testosterone production over 5 h, but this effect was variable in magnitude and was not completely reproducible. Co-perifusion of isolated s-tubules with Percoll-purified Leydig cells for 6 h produced significant and consistent increases in Leydig cell testosterone secretion compared with Leydig cells perifused on their own. In six experiments, s-tubules enhanced Leydig cell testosterone secretion by 26 +/- 5% (P less than 0.001) in the absence of LH stimulation and by 48 +/- 11% following pulsatile stimulation with 1 ng/ml ovine LH (oLH). The presence of s-tubules enhanced (P less than 0.01-0.001) testosterone secretion by Leydig cells in response to pulses of oLH at doses ranging from 0.1 to 10 ng/ml, but the magnitude of enhancement was greatest with 0.1 and 1 ng/ml doses. These stimulatory effects were not explained by Leydig cell contamination or by testosterone leakage from the isolated s-tubules. Co-perifusion of Leydig cells with isolated epididymal tubules as a control tissue had no significant effect on LH-stimulated Leydig cell testosterone production. Stimulatory effects of s-tubules on Leydig cell testosterone secretion were observed at a 'physiological' ratio of s-tubules to Leydig cells (200 cm tubules/3 million cells) and was mediated by a humoural agent(s), since perifusion of s-tubules and Leydig cells in series gave similar results to co-perifusion of these tissues. This system proved to be robust and, in contrast to static culture systems, gave highly reproducible results, which should allow detailed investigation of the dynamic interactions between s-tubules and Leydig cells and the hormonal control of these events.     

糖皮质激素诱导大鼠睾丸间质细胞凋亡的研究

目的 :研究糖皮质激素诱导不同发育阶段培养的大鼠睾丸间质细胞凋亡状况。方法 :以Annexin V FITC和PI双标细胞 ,应用激光共聚焦显微镜和流式细胞仪检测。　结果 :ILC、ALC经皮质酮处理后 ,其凋亡量显著高于对照组 ;PLC经皮质酮处理后 ,其凋亡量与对照组无显著差异。　结论 :糖皮质激素能诱导大鼠睾丸未成熟型和成熟型间质细胞凋亡 ,而不能诱导前体型间质细胞凋亡。     

Effects of varicocele on testosterone, apoptosis and expression of StAR mRNA in rat Leydig cells

The aim of this study was to explore the effects of varicocele on the morphology and function of Leydig cells in the rat testis. Forty male Sprague-Dawley rats were divided into two groups: the experimental group underwent surgery to create a left varicocele (VC), and the control group underwent a sham operation. Serum testosterone and intratesticular testosterone levels were measured using a radioimmunoassay after 4 and 8 weeks of operation. Leydig cells were studied for apoptosis and expression of steroidogenetic acute regulatory (StAR) protein mRNA levels. Serum testosterone levels declined after 4 and 8 weeks of operation but were not significant (P>0.05). However, the intratesticular testosterone levels after 8 weeks were significantly decreased compared with the control group (P<0.01). The mean apoptosis index of Leydig cells in the experimental group was significantly higher than that in the control group after 4 or 8 weeks (P<0.01). StAR mRNA levels in the Leydig cells of the experimental group were significantly lower compared to those of the control group (P<0.01). Our data show that varicocele did impair Leydig cell function by increasing apoptosis and suppressing the expression of the StAR protein.     

Evidence that testosterone regulates Leydig cell 3 beta-hydroxysteroid dehydrogenase-isomerase activity by a trans-acting factor distal to the androgen receptor.

Leydig cells are a target for their own steroid product, testosterone, and thus could be subject to short-loop feedback regulation by androgens. The authors previously reported that 3 beta-hydroxysteroid dehydrogenase-isomerase (3 beta HSD) activity was higher in freshly isolated Leydig cells from C57BL/6J than those from C3H/HeJ inbred mice. To determine whether this strain-related difference in 3 beta HSD activity could be mediated by differential sensitivity to feedback effects of testosterone, Leydig cells from the two strains were cultured in the presence or absence of testosterone, the synthetic androgen receptor agonist, mibolerone, or the nonaromatizable androgen, dihydrotestosterone. After 7 days of treatment, all three androgens significantly decreased 3 beta HSD activity in Leydig cells from C57BL/6J, but not from C3H/HeJ mice. When Leydig cells were cultured with hydroxyflutamide, an androgen receptor antagonist, the effect of testosterone was negated. To determine whether the strain-related difference in sensitivity to testosterone was mediated by a difference in the androgen receptor protein, Leydig cells from reciprocal F1 hybrid lines of mice were cultured in the presence or absence of testosterone. Testosterone treatment inhibited 3 beta HSD activity in both F1 lines to the same extent as observed for Leydig cells from C57BL/6J mice. Thus, there is a strain-related difference in the response to testosterone, but it cannot account for the strain-related difference in Leydig cell 3 beta HSD activity because the high 3 beta HSD strain (C57BL/6J) is the sensitive strain. Although the effect on C57BL/6J Leydig cells is androgen receptor-mediated, the dominant effect of testosterone on both F1 lines rules out a difference in the androgen receptor protein per se. However, the data are consistent with the difference being in a trans-acting factor distal to the androgen receptor.     

Leydig cell cooperation in vitro: evidence for communication between adult rat Leydig cells

In short-term incubations (32 C, 3 h) of purified adult rat Leydig cells, increasing the density from 5000 to 50,000 cells/16 mm diameter culture well caused a significant increase in human chorionic gonadotropin (hCG)-stimulated testosterone secretion/cell. Density-dependent stimulation was also observed under basal conditions and in the presence of dibutyryl cyclic adenosine monophosphate, luteinizing hormone-releasing hormone, or 22-hydroxy cholesterol. In contrast, increasing the incubation density of purified Leydig cells by addition of other testicular cells had no effect on basal or hCG-stimulated testosterone secretion. hCG-stimulated testosterone secretion by Leydig cells incubated at low density was also increased by addition of Leydig cell-conditioned medium. This stimulatory activity was removed by charcoal extraction and by ultrafiltration (approximately 30 kDa cut-off). The data indicate that Leydig cells cooperate by secretion of low molecular weight, cell-specific stimulatory factors that support Leydig cell steroidogenesis in vitro, and may also play a role in regulating Leydig cell function in vivo.     

Heterogeneity of adult mouse Leydig cells with different buoyant densities.

The authors investigated the morphologic characteristics and human chorionic gonadotrophin (hCG)-stimulated testosterone production of adult mouse Leydig cells in vitro, which have different buoyant densities. Leydig cells from five testes of Swiss outbred male mice (15 weeks old) were isolated and purified by mechanical dispersion followed by density gradient centrifugation using Percoll. Two groups of Leydig cells were obtained with different buoyant densities: group 1 had densities of 1.0667 to 1.0515 g/cm3 and group 2 had densities of 1.0514 to 1.0366 g/cm3. In vitro testosterone production of these Leydig cells, in response to different doses of hCG (0, 5, 25, 125, 625, and 3125 pg/mL), was determined by radioimmunoassay. Leydig cells were fixed and processed for electron microscopic stereology to quantify the organelles by volumes and surface area. In Leydig cells of Group 1, testosterone production per cell in vitro in response to 0 and 5 pg/mL hCG was not significantly different (P greater than 0.05). Increases in the dose up to 25 pg/mL produced a significant increase (P less than 0.05) in testosterone production, although hCG doses of 125 and 625 pg/mL did not produce further increases in testosterone levels. However, 3125 pg/mL hCG further elevated the testosterone production by those Leydig cells with high buoyant density. In Leydig cells in group 2, the patterns of testosterone production in response to hCG doses of 0, 5, and 25 pg/mL were similar to those of Leydig cells in group 1. Those Leydig cells with low buoyant density, however, were unable to stimulate further testosterone production by an hCG dose of 3125 pg/mL.(ABSTRACT TRUNCATED AT 250 WORDS)     

小鼠胚胎睾丸Leydig细胞培养、纯化及其功能研究

目的:探讨小鼠胚胎睾丸Leyd ig细胞体外培养、鉴定、纯化的方法,并进行形态学观察、分泌睾酮能力等生物学特性检测。方法:选择胎龄16 d的胎鼠睾丸,0.03%胶原酶Ⅰ消化,3β-羟基类固醇脱氢酶(HSD)染色鉴定及纯度测定,锥虫蓝染色检测细胞活率。放免法测定Leyd ig细胞不同培养时间及密度下分泌睾酮的水平。结果:Leyd ig细胞培养前和培养72 h后纯度分别为(45.10±1.66)%和(81.17±2.32)%;培养液中可检测到睾酮,睾酮水平与Leyd ig细胞数、培养时间相关,单个Leyd ig细胞睾酮分泌能力逐日下降。结论:该法分离的胚胎Leyd ig细胞纯度较高,生长性好,保持增殖和分泌睾酮的生物学特性,可应用于相关的研究。