玉米赤霉烯酮对体外培养猪卵巢颗粒细胞的影响

以原代培养的猪卵巢颗粒细胞为模型,设立玉米赤霉烯酮(ZEA)对照组(0.0 mg/L)及高(80.0 mg/L)、中(20.0,40.0mg/L)、低(0.2,2.0mg/L)剂量组,比较不同质量浓度ZEA对体外培养猪卵巢颗粒细胞的影响。形态学观察发现,随着ZEA质量浓度的增加,颗粒细胞呈散在生长,体积缩小变圆,数量减少;高剂量组(80.0mg/L)中,76.96%细胞均已脱壁死亡。MTT法表明,ZEA对卵巢颗粒细胞具有生长抑制作用;免疫荧光结果显示随ZEA质量浓度的增加,细胞凋亡率逐渐升高,高质量浓度组细胞增殖率仅为1.01%;Western blot检测结果显示经ZEA处理,Fas、FasL、FADD、Caspase-10的表达量均明显上调,且存在质量浓度-效应关系。结果表明,ZEA能诱导卵巢颗粒细胞凋亡,并显著上调Fas、FasL、FADD、Caspase-10的表达,可通过死亡受体通路介导卵巢颗粒细胞发生凋亡。     

Comparison of effects of leptin and ghrelin on porcine ovarian granulosa cells

The aim of our studies was to compare the roles of leptin and ghrelin in the direct control of proliferation, apoptosis, and secretory activity by porcine ovarian cells. In our in vitro experiments, we analyzed the effects of leptin and ghrelin treatments (at 0, 1, 10, or 100 ng/mL medium) on the accumulation of proliferation-related peptides (PCNA, cyclin B1, MAP kinase [MAPK]) and apoptosis-associated peptides (Bax, caspase 3, p53), and on progesterone secretion by cultured porcine granulosa cells, using immunocytochemistry, SDS PAGE-Western immunoblotting, and radioimmunoassay (RIA). Leptin stimulated proliferation (PCNA, cyclin B1, MAPK), apoptosis (Bax, p53), and progesterone secretion. Ghrelin promoted proliferation (PCNA, cyclin B1, MAPK) and progesterone secretion but suppressed apoptosis (Bax, caspase 3, p53). These observations suggest that both leptin and ghrelin directly control proliferation, apoptosis, and secretory activity by porcine ovarian cells. At the level of the ovary, in contrast to the hypothalamo-hypophysial system, leptin and ghrelin may have similar action in promoting granulosa cell proliferation and progesterone secretion, but they may be antagonistic to one another (leptin, stimulator; ghrelin, inhibitor) in controlling apoptosis.     

淫羊藿苷在猪卵泡体外培养过程中对颗粒细胞凋亡的抑制作用

本试验旨在研究淫羊藿苷(ICA)对猪卵泡体外培养过程中颗粒细胞凋亡的影响。设置不同浓度ICA(0、01、1、10μg/mL)添加组,体外培养猪3~5 mm健康有腔卵泡12 h和24 h后,分别收集各组卵泡颗粒细胞,流式细胞仪检测细胞凋亡率,RT-PCR检测凋亡相关基因Caspase-3、Bcl-2和Bax mRNA相对表达水平。结果表明,猪卵泡体外培养12 h和24 h,添加1μg/mL ICA组颗粒细胞凋亡率较对照组显著降低(P005),1μg/mL组的Caspase-3、Bax mRNA表达量最低,Bcl-2 mRNA表达量最高,且显著高于对照组(P005)。研究结果提示,ICA在卵泡闭锁过程中可明显抑制颗粒细胞凋亡,这一作用可能主要是通过抑制线粒体凋亡途径而实现的。     

miR-15a对猪卵泡颗粒细胞BDNF基因表达的影响

为探索miR-15a对猪卵泡发育的影响,选取健康大卵泡、中等卵泡和闭锁卵泡,研究不同卵泡中miR-15a的相对表达量以及其是否对卵巢颗粒细胞中有BDNF表达具有调节作用。分别抽取直径3-5 mm、大于5 mm健康卵泡和3-5 mm闭锁猪卵泡,采用q PCR检测发现闭锁卵泡中miR-15a表达显著升高。免疫组化结果显示中等健康卵泡颗粒细胞上BDNF、Tr KB均有表达,而在靠近卵泡腔的凋亡颗粒细胞BDNF免疫阳性反应较弱。分离培养猪卵巢颗粒细胞,过表达miR-15a能显著上调BDNF基因表达水平,Bcl-2基因表达有下降趋势但差异不显著;抑制miR-15a表达能显著抑制BDNF、bcl-2基因表达水平。Western-Blot结果发现,过表达miR-15a显著下调BDNF蛋白水平,而抑制miR-15a表达则能显著上调BDNF蛋白水平。实验结果显示miR-15a可能经由其靶基因BDNF参与猪卵泡的发育和闭锁。     

Isorhamnetin protects zearalenone-induced damage via the PI3K/Akt signaling pathway in porcine ovarian granulosa cells

Zearalenone(ZEA) is widely derived from moldy cereal grain, which has adverse effects on animal reproduction. In particular, pigs are more sensitive to ZEA-induced toxicity than other animals. Isorhamnetin has extensive pharmacological activity. However, the role of isorhamnetin in ZEA-induced cytotoxicity remains unclear. This study was designed to investigate the therapeutic effect of isorhamnetin on ZEA-induced damage in porcine ovarian granulosa cells and elucidate its molecular mechanism. T...     

醋酸铅对小鼠卵巢组织结构和卵巢颗粒细胞凋亡的影响

将40只20日龄雌性昆明系小鼠随机分成3个处理组和1个对照组,每组10只。给3个处理组小鼠分别连续2d腹腔按体质量注射醋酸铅10,20,40mg/kg,对照组小鼠注射等体积的生理盐水。于注射后24,72h分离卵巢,用原位末端标记法(TUNEL)测定卵巢颗粒细胞的凋亡率,研究卵巢组织结构及卵巢颗粒细胞凋亡的变化。结果显示,醋酸铅可使小鼠卵巢组织结构发生病变,加速卵巢颗粒细胞的凋亡,且凋亡率随着攻毒剂量的增加和时间的延长而升高,与对照组相比,差异极显著(P0.01);表明醋酸铅对小鼠卵巢具有毒性作用,可诱导卵巢颗粒细胞发生凋亡,并呈现一定的剂量-时间依赖关系。     

Kisspeptin在牛卵巢颗粒细胞的表达及功能研究

为明确kisspeptin在牛卵巢颗粒细胞的表达和功能,本试验首先利用免疫荧光技术研究了kisspeptin在牛卵巢颗粒细胞的表达,随后利用MTT和ELISA技术研究了不同浓度的kisspeptin-10(Kp10)对牛卵巢颗粒细胞增殖和孕酮分泌的影响。结果表明,kisspeptin在牛卵巢颗粒细胞有表达,10、100、1 000nmol/L的Kp10处理24h,均可以极显著提高牛卵巢颗粒细胞活力(P0.01);100nmol/L的Kp10处理24、72h,可极显著提高牛卵巢颗粒细胞的活力(P0.01),但处理48h未能显著提高细胞活力(P0.05)。100nmol/L的Kp10处理24h,可显著提高牛卵巢颗粒细胞孕酮的分泌水平(P0.05),而10、1 000nmol/L的Kp10对孕酮分泌无显著影响(P0.05)。研究结果提示kisspeptin可促进牛卵巢颗粒细胞增殖和孕酮分泌。     

miR-18a通过靶向结合CTGF调控猪颗粒细胞凋亡

为探究miR-18a对猪卵巢颗粒细胞凋亡的调控作用,利用生物信息学分析、荧光素酶活性检测和体外培养颗粒细胞试验验证miR-18a对CTGF的靶向作用及其在猪颗粒细胞中对CTGF基因表达的影响,并通过流式细胞技术检测其对猪卵巢颗粒细胞凋亡的调控作用。生物信息学分析结果表明,CTGF是miR-18a的潜在靶基因,荧光素酶活性检测进一步验证了miR-18a与CTGF的结合。在培养的颗粒细胞中转染miR-18a模拟物后,qRT-PCR和Western blot结果显示CTGF的mRNA和蛋白水平均显著降低,流式细胞技术检测表明miR-18a显著促进颗粒细胞的凋亡。而转染miR-18a抑制剂后,猪颗粒细胞的凋亡率显著降低,共转染miR-18a抑制剂和CTGF的干扰RNA后,颗粒细胞的凋亡率呈现回升。试验结果表明miR-18a通过靶向结合CTGF基因调控猪颗粒细胞的凋亡。     

Effects of ghrelin and its analogues on chicken ovarian granulosa cells

The aim of these in vitro experiments was (1) to examine the effects of ghrelin on the basic functions of ovarian cells (proliferation, apoptosis, secretory activity); (2) to determine the possible involvement of the GHS-R1a receptor and PKA- and MAPK-dependent post-receptor intracellular signalling cascades; (3) to identify the active part of the 28-amino acid molecule responsible for the effects of ghrelin on ovarian cells. We compared the effect of full-length ghrelin 1-28, a synthetic activator of GHS-R1a, GHRP6, and ghrelin molecular fragments 1-18 and 1-5 on cultured chicken ovarian cells. Indices of cell apoptosis (expression of the apoptotic peptide bax and the anti-apoptotic peptide bcl-2), proliferation (expression of proliferation-associated peptide PCNA), and expression of protein kinases (PKA and MAPK) within ovarian granulosa cells were analysed by immunocytochemistry. The secretion of progesterone (P(4)), testosterone (T), estradiol (E(2)) and arginine-vasotocin (AVT) by isolated ovarian follicular fragments was evaluated by RIA/EIA. It was observed that accumulation of bax was increased by ghrelin 1-28, GHRP6 and ghrelin 1-18, but not by ghrelin 1-5. Expression of bcl-2 was suppressed by addition of ghrelin 1-28, GHRP6 and ghrelin 1-5, but promoted by ghrelin 1-18. The occurrence of PCNA was reduced by ghrelin 1-28, GHRP6, ghrelin 1-18 and ghrelin 1-5. An increase in the expression of MAPK/ERK1, 2 was observed after addition of ghrelin 1-28, GHRP6 and ghrelin 1-18, but not ghrelin 1-5. The accumulation of PKA decreased after treatment with ghrelin 1-28 and increased after treatment with GHRP6 and ghrelin 1-18 but not ghrelin 1-5. Secretion of P(4) by ovarian follicular fragments was decreased after addition of ghrelin 1-28 or ghrelin 1-5 but stimulated by GHRP6 and ghrelin 1-18. Testosterone secretion was inhibited by ghrelins 1-28 and 1-18, but not by GHRP6 or ghrelin 1-5. Estradiol secretion was reduced after treatment with ghrelin 1-28 but stimulated by ghrelins 1-18 and 1-5; GHRP6 had no effect. AVT secretion was stimulated by ghrelin 1-28, GHRP6 and ghrelin 1-18, but inhibited by ghrelin 1-5. The comparison of the effects of the four ghrelin analogues on nine parameters of ovarian cells suggest (1) a direct effect of ghrelin on basic ovarian functions-apoptosis, proliferation, steroid and peptide hormone secretion; (2) that the majority of these effects can be mediated through GHS-R1a receptors; (3) an effect of ghrelin on MAPK- and PKA-dependent intracellular mechanisms, which can potentially mediate the action of ghrelin at the post-receptor level; (4) that ghrelin residues 5-18 may be responsible for the major effects of ghrelin on the avian ovary.     

miR-1307在猪卵巢颗粒细胞周期中的作用

为了解猪miR-1307序列和结构特征,阐明其在猪卵巢颗粒细胞周期中的作用,利用生物信息学方法分析猪miR-1307的序列特征、染色体定位和潜在的生物学功能;在体外培养的猪卵巢颗粒细胞中转染miR-1307模拟物(mimics)和抑制剂(inhibitor),利用流式细胞术检测细胞周期。结果显示:猪miR-1307前体序列长度为80 bp,其核苷酸序列(包括成熟序列和种子序列)和基因组定位等与哺乳动物其他物种高度一致;功能富集分析发现miR-1307靶基因富集在rRNA分解代谢进程和蛋白酪氨酸磷酸酶活性等多个重要的生物学进程和分子功能中;在猪卵巢颗粒细胞中,过表达miR-1307可使G0/G1期细胞比例增加,S期细胞比例显著降低(P<0.05);抑制miR-1307可使G0/G1期细胞比例降低,S期细胞比例显著增加(P<0.05)。结果表明:miR-1307是猪卵巢颗粒细胞周期的重要调节因子。     

玻璃化冷冻预处理方法对牛卵巢颗粒细胞的影响

为了研究不同玻璃化冷冻预处理对牛卵巢颗粒细胞培养的影响,试验采用4种不同的玻璃化冷冻预处理方法(①将冷冻保存管直接投入液氮罐中;②将冷冻保存管先置于4℃冰箱15 min,然后投入液氮罐中;③将冷冻保存管先置于-20℃冰箱10 min,然后投入液氮罐中;④将冷冻保存管先置于4℃冰箱15 min,再置于-20℃冰箱10 min,然后投入液氮罐中)处理牛卵巢颗粒细胞,解冻后检测细胞活力和传代时间。结果表明:解冻后4种方法的细胞活力分别为72%、74%、79%和86%;传代时间分别为76 h、73 h、67 h和62 h;方法④的细胞活力和传代时间与其他组比较差异显著(P<0.05)。说明玻璃化冷冻预处理方法有利于复苏后的牛卵巢颗粒细胞的进一步培养。     

Evaluation of RNA interference in developing porcine granulosa cells using fluorescence reporter genes

Gene silencing using small interfering RNA (siRNA) may be useful for functional analyses of unidentified genes expressed during cell differentiation. The present study was performed to evaluate RNA interference (RNAi) in porcine granulosa cells stimulated with bovine FSH, by using two fluorescence reporter genes: a plasmid encoding green fluorescent protein (GFP) and a plasmid encoding red fluorescent protein (RFP). The siRNA targeting GFP mRNA sequence (GFP-siRNA) with both plasmids was introduced into cultured cells by lipofection. GFP- and RFP-expressing cells were observed under fluorescence microscopy and analyzed by flow cytometry. Strong fluorescence was observed after introduction of both plasmids into cells. The intensity of green fluorescence generated by GFP was greatly suppressed by introduction of GFP-siRNA, showing an approximate 70% decrease in the ratio of green to red fluorescence. Consequently, we concluded that gene silencing by siRNA can be used to analyze the functions of genes of interest during differentiation of porcine granulosa cells.     

BMP-2 and -6 modulate porcine theca cell function alone and co-cultured with granulosa cells

Bone morphogenetic proteins (BMPs) are emerging as a family of proteins crucial in the regulation of fertility and ovulation rate. We have shown that porcine theca cells express BMP receptors, however, there is a paucity of information regarding the effect(s) of BMPs on theca cell function. The purpose of this study was to investigate the effects of BMP-2 and -6 on theca cells cultured under serum-free conditions in terms of steroidogenesis, cAMP release and proliferation. The study was further extended to determine whether BMP responses in theca cells are affected by the addition of granulosa cells to the culture system. Both BMPs suppressed progesterone and androstenedione synthesis by theca cells (P < 0.05) after 144 h in culture. Oestradiol synthesis was suppressed (P < 0.05) by BMP-2, but not BMP-6, and theca cell proliferation was stimulated (P < 0.05) by BMP-6, but not BMP-2, after 144 h in culture. Both BMP-2 and -6 inhibited cAMP release (P < 0.05) by theca cells. Furthermore, progesterone and androstenedione synthesis by co-cultured theca and granulosa cells were suppressed (P < 0.05) whereas cell proliferation was stimulated (P < 0.05). These results provide strong evidence for a functional BMP system in the porcine ovary and that theca cells are responsive to BMPs in terms of steroidogenesis and proliferation. BMP-2 and -6 may have a role as luteinisation inhibitors in this polyovular species.     

Time-related changes of the cardiovascular system during maintenance anesthesia with sevoflurane and isoflurane in horses.

To clarify time-related changes in equine cardiovascular system during maintenance anesthesia (180 min, 1.2 minimum alveolar concentration) with sevoflurane (Sev-group) compared to isoflurane (Iso-group) as the basis for clinical use of Sev, horses were examined for the heart rate (HR), mean arterial pressure (MAP), cardiac index (CI), systemic vascular resistance (SVR) and pre-ejection period (PEP)/ejection time (ET) that is an index of the cardiac contractility. The HR was almost 30 beats/min in both groups without significant temporal change. MAP was significantly elevated with time but there was no significant difference between the groups. In the Sev-group, CI remained unchanged but the significant increase of CI with time was observed in the Iso-group. In the Sev-group SVR was significantly higher than that of the Iso-group and increased with time. No significant difference of PEP/ET was seen between the groups, but PEP/ET lowered with time in the Iso-group in association with prolonged ET. The results indicated that the time-dependent elevation of MAP in the Sev-group reflected increased SVR without increase of CI and that it reflected increased CI resulting from increased stroke volume in the Iso-group in association with lowered PEP/ET, that is, increased cardiac contractility.     

Gonadotropin-releasing hormone inhibition of LH stimulated progesterone secretion by porcine granulosa cells in vitro

GnRH has several direct actions on rat granulosa cells. Specific receptors for GnRH have been demonstrated on rat and human ovaries. Whether the porcine ovary has specific receptors for GnRH is still debated and the physiological actions of GnRH on porcine granulosa cells have not yet been clarified. Consequently, we have examined the actions of a GnRH agonist (GnRHa) on basal and LH stimulated progesterone secretion by porcine granulosa cells. GnRHa inhibited both basal and LH stimulated progesterone secretion by granulosa cells from medium (3-5 mm) and large (6-10 mm) antral follicles during 3 day incubations. LH stimulated progesterone secretion was more sensitive to inhibition than basal progesterone secretion. Studies on the time course for GnRHa inhibition of progesterone secretion indicated that the decrease in progesterone secretion occurred 48 to 72 hr after first exposure to GnRHa. Earlier inhibition occurred in only a fraction of the experiments. GnRHa did not have to be present during the time when inhibition occurred. Incubations of 2 days with GnRHa were just as effective as 3 day incubations at inhibiting progesterone secretion on day 3. Furthermore, a 30 min exposure to GnRHa on day 1 was just as inhibitory as a full 2 day incubation with GnRHa in inhibiting LH stimulated progesterone secretion on day 3. Incubation of the cells for 3 days prior to exposure of the cells to GnRHa did not alter the time course for GnRHa action. GnRHa did not alter the DNA content of the cultures in up to 6 day incubations or the number of viable cells attached to the wells in up to 3 day incubations.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cellular changes in the granulosa layer of the maturing ovarian follicle of the domestic fowl

1. The relationships between length, width and height of the maturing ovarian follicle of the domestic fowl (Gallus domesticus) are shown.

2. During the rapid‐growth phase (yolk deposition) of the oocyte, i.e. an increase in size from about 9 mm diameter to 35 mm diameter, there is about a 15‐fold increase in its surface area. During this time the number of granulosa cells adjacent to the oocyte increases by about 5‐fold.

3. The granulosa cells become flatter during the growth period of the follicle, consequently increasing their surface area adjacent to the oocyte by about 3‐fold.

4. Together the change in shape of the granulosa cells and the increase in their number account for the increase in area of the granulosa layer during follicular growth.

5. Measurement of the DNA content of the granulosa layer indicated a progressive decrease in the cellular content of DNA as the follicle matures.     

Upregulation of P-glycoprotein activity in porcine oocytes and granulosa cells during in vitro maturation

Multidrug resistance P-glycoprotein (Pgp), coded by the multidrug resistance type I (MDR1/ABCB1) gene, is an energy-dependent efflux pump and functions in systemic detoxification processes. In the present study, the expression and development of Pgp were evaluated in the porcine oocyte during in vitro maturation to compare with the expression of Pgp in cultured granulosa cells. As revealed by Western blotting using anti-human Pgp antibody, a single band of Pgp with an apparent molecular size of 170 kDa was detected in the germinal vesicle stage oocytes. The surface of GV oocyte was positively labeled by immunostaining. In the second metaphase oocyte after culture in the maturation medium containing porcine follicular fluid and human chorionic gonadotropin, the level of Pgp was increased. The elevation of the oocyte Pgp level was associated with increased activity of rhodamine 6G efflux from the oocyte, and its efflux was suppressed by verapamil, an inhibitor of Pgp. Removal of porcine follicular fluid from the maturation medium resulted in little alteration of the oocyte Pgp level. Expression of Pgp was also elevated in cultured porcine granulosa cells during cell maturation when stimulated with follicle-stimulating hormone or luteinizing hormone for 24-48 h. Collectively, the present results indicate that the transporting activity of P-glycoprotein upregulates in porcine oocytes and granulosa cells during exposure to gonadotropins or prior to ovulation.     

Immunohistochemical diagnosis of canine ovarian epithelial and granulosa cell tumors.

In humans and canines, the morphology of granulosa cell tumors is extremely variable and causes diagnostic difficulties. In human pathology, immunohistochemistry has been widely used for the diagnosis of granulosa cell tumors, whereas, limited studies are present in canine species. The aim of this study was to investigate the expression of cytokeratins, vimentin, and inhibin-alpha in canine normal ovaries, epithelial ovarian tumors, and granulosa cell tumors to establish an immunohistochemical panel for the differential diagnosis of ovarian tumors. Formalin-fixed, paraffin-embedded tissue sections from 4 normal ovaries, 8 granulosa cell tumors, and 6 epithelial ovarian tumors (2 adenomas and 4 adenocarcinomas) sections were obtained and stained with hematoxylin and eosin and immunohistochemically for cytokeratin AE1/AE3, cytokeratin 7, vimentin, and inhibin-alpha. In normal ovaries, cytokeratin 7, cytokeratin AE1/AE3, and vimentin were expressed in the surface epithelium. Granulosa cells were negative for cytokeratin 7 and displayed variable expression of vimentin, cytokeratin AE1/AE3, and inhibin-alpha toward follicular maturation. Granulosa cell tumors were negative for cytokeratin 7 and positive for inhibin-alpha. Conversely, ovarian epithelial cells tumors were positive for cytokeratin 7 and negative for inhibin-alpha. Both granulosa and epithelial cell tumors displayed variable expression of vimentin. Cytokeratin AE1/AE3 was expressed by all epithelial-derived tumors and 6 of 8 granulosa cell tumors. The results of this study suggest that useful immunohistochemical markers to distinguish epithelial ovarian tumors from granulosa cell tumors are cytokeratin 7 and inhibin-alpha.     

Role of cell-death ligand-receptor system of granulosa cells in selective follicular atresia in porcine ovary

In the mammalian ovary, more than 99% of follicles degenerate without ovulation and few oocytes ovulate and succeed to the next generation. Granulosa cell apoptosis plays a critical role in this process, follicular atresia. However, the molecular mechanisms responsible for the regulation of granulosa cell apoptosis have not been clarified. Death ligand and receptor systems are major apoptosis-inducing factors. This review describes the granulosa cell apoptosis via death ligand and receptor systems during follicular atresia in the porcine ovary.