雌、孕激素对去卵巢家兔子宫内膜鞘糖脂表达的影响

用雌、孕激素处理去卵巢家兔后观察子宫内膜鞘糖脂的含量和组成。结果表明、雌激素处理后、子宫内膜Gls含量是孕激素处理的十余倍,而孕激素增加NGSL含量的作用却比雌激素更强。两种激素对鞘糖脂组分的影响也明显不同。雌激素给药组子宫内膜鞘糖脂以多糖基组分GD_3 GT_(1b) CPH为主,孕激素组则以短糖链组分GM_3 CMH CDH为主。雌激素预先作用后再用孕激素或雌、孕激素同时给药,与单用雌激素后比较其短糖链组分明显增加,多糖基组分则明显减少,表现出两者的共同作用。上述结果提示:雌、孕激素对鞘糖脂代谢影响明显不同,雌激素使糖链复杂化、孕激素则使糖链趋向于简单。     

人体子宫内膜中性鞘糖脂和神经节苷脂的含量和组成在月经周期中和妊娠时的变化

从月经周期各期、早妊(6—8周)及足月妊娠子宫内膜中提取、纯化了神经节苷脂(Gls)和中性鞘糖脂(N-GSL),分别测定了其含量。对两类鞘糖脂的组成进行了HPTLC图谱分析。初步观察了不同时期子宫内膜中CMP—NeuAc:LacCer唾液酰转移酶(ST_1)和CMP-NeuAc:CM_3唾液酰转移酶(ST_2)的活性。结果表明:分泌期的GLs总含量低于增生期(P<0.02);分泌期GD_3含量较生长期增多(P<0.01);妊娠后,GM_3含量增加,而GD_3减少;相应地,ST_1活性增高,ST_2活性降低。分泌期CMH含量为增生期的4.7倍。结果提示子宫内膜鞘糖脂含量和组成的变化可能与子宫的功能有关,而且受女性激素水平的影响。     

原发不育症子宫内膜花生凝集素受体的研究

本文以PNA(花生凝集素)为探针,应用ABC亲和组化技术,对69例原发不育症患者的子宫内膜PNA受体进行了检测.结果表明,原发不育症子宫内膜的增生期、分泌期PNA受体的阳性率均显著低于年龄相似、有生育史的对照组子宫内膜的阳性率.不育症子宫内膜分泌欠佳的PNA受体阳性率显著低于不育症分泌期不同时期子宫内膜的阳性率.提示,这种差异可能与雌孕激素对两组子宫内膜作用水平的不同引起.     

人正常子宫肌肉的鞘糖脂组成及其在不同生理功能阶段的变化

本文测定了新生儿、生育期、更年期和足月妊娠人子宫肌肉的神经节苷脂(Gg)与中性鞘糖脂(N-GSL)的含量,比较了两种鞘糖脂的HPTLC谱。新生儿期Gg的总含量(以脂结合唾液酸LBSA量表示)最高,每克湿重组织约45.2μg,足月妊娠子宫肌肉中的含量最低,为10.4μg,生育期为32.8μg、更年期为39.5μg。N—GSL的含量却以足月妊娠子宫肌肉中最多,达99.4μg。按HPTLC谱分析子宫肌肉中Gg的主要组分为GD_3和GM_3,在子宫发育成熟与妊娠时,肌肉组织中这两种组分的含量变化明显:生育期样品的GD_3由新生儿的25.4％增加到56.6％(按占LBSA总量的百分比计算),GM_3则由33.2％降至16.9％。此外,GM_1和GD_(1a)也明显减少。N—GSL在生育期CMH、CDH和CTH的含量(按占含糖基量的百分比计算)成倍增加,而含五糖基以上的组分则仅为新生儿子宫的1/5。足月妊娠与新生儿子宫肌肉的两类鞘糖脂的HPTLC谱类似,但前者GT1b占19.4％,明显高于新生儿样品(6.1％)。     

鞘糖脂研究进展

鞘糖脂位于细胞膜脂质双分子层,是哺乳动物细胞膜上的必需组成成分之一,参与细胞的多种生物学活动,其生物学功能非常复杂。在免疫应答、细胞发育、细胞识别及分化中都发挥重要的作用。组织器官中鞘糖脂的异常表达往往与各种疾病具有明显的相关性。因此鞘糖脂的结构表征、构效关系研究以及与之相关的鞘糖脂生物合成及分解代谢途径的研究已成为近年来的热点问题。最近研究也表明鞘糖脂在疾病的发生发展及治疗过程中都具有至关重要的作用。对鞘糖脂的结构与功能的关系、糖脂的合成代谢以及糖脂的分离分析方法作一综述。     

Interferons and the maternal–conceptus dialog in mammals

Two-way communication between the conceptus and the mother during early pregnancy is essential if the pregnancy is to survive. In this review, our primary focus is on biochemical communication between the conceptus and mother in the ruminant ungulate species. We emphasize, in particular, the role played by interferon-tau (IFNT) in triggering maternal responses in cattle and sheep and how maternal factors intervene to up-regulate IFNT gene (IFNT) expression in trophoblast. However, we also consider the possibility that different signaling cytokines or the physical presence of trophoblast may induce a partial IFN response in endometrium of those species where there is no evidence for large scale trophoblast IFN production. Conceivably, disparate signaling mechanisms trigger common downstream events necessary to secure a successful pregnancy.     

Effect of estrus induction on prostaglandin content and prostaglandin synthesis enzyme expression in the uterus of early pregnant pigs

Prostaglandins (PGs) play a pivotal role in maternal recognition of pregnancy and implantation in pigs. In the present study, PGE₂, PGF_2α, and PGFM (PGF_2α metabolite) content, as well as PGE₂ synthase (mPGES-1) and PGF_2α synthase (PGFS) expression was investigated in early pregnant gilts with natural (n = 21) and PMSG/hCG-stimulated (n = 19) estrus. Endometrial tissue samples, uterine luminal flushings (ULFs), and blood serum were collected on days 10-11, 12, and 15 after insemination. Additionally, day 15 conceptuses were collected for mPGES-1 and PGFS protein expression. Effect of estrus induction was observed on day 15 of pregnancy, when the content of PGE₂ in the uterine lumen was fourfold lower in gonadotropin-stimulated gilts in comparison to controls (P < 0.001). Decreased PGE₂ content in ULFs of gonadotropin-treated pigs was preceded by lower endometrial mPGES-1 gene expression in hormonally-stimulated animals in comparison to control gilts (P < 0.01). On the other hand, estrus induction with PMSG/hCG resulted in higher PGE₂ accumulation in the endometrial tissue on day 15 of pregnancy (P < 0.01). Furthermore, PGF_2α content in the endometrium and PGFM levels in blood serum were lower in gonadotropin-treated gilts, especially on day 12 after insemination when compared to control gilts (P < 0.01). Finally, PGFS expression in day 15 conceptuses was decreased in animals with hormonally-induced estrus. We conclude that PMSG/hCG stimulation of prepubertal gilts to induce estrus results in changes of PG production and secretion during early pregnancy, which, in turn, may affect conceptus development, implantation, and the course of pregnancy.     

Influences of treatment of early pregnant mares with the progestin altrenogest on embryonic development and gene expression in the endometrium and conceptus

A positive influence of altrenogest treatment on a retarded development of the conceptus around the beginning of placentation in mares older than 8 years could be recently demonstrated. In the present study, effects of altrenogest treatment in early-pregnant mares on conceptus development and expression of endometrial and embryonic genes were investigated. Genes were chosen according to a possible involvement in embryo-maternal interaction and embryonic development in the equine species. Mares were treated with altrenogest (0.044 mg/kg bodyweight) or sunflower oil (placebo) from day 5 to 11 after ovulation. Embryos (altrenogest n = 13, placebo n = 12) and biopsies were collected on day 11. Pregnancy rate and embryonic size were not influenced by treatment (embryonic diameter: altrenogest 7.0 ± 2.5, placebo 6.5 ± 1.7 mm, n.s.). The percentage of luminal epithelial cells, superficial glandular epithelial cells and interstitial cells with nuclei staining positively for the progesterone receptor was significantly lower (P < 0.05) in samples collected from altrenogest-treated than from placebo-treated mares (e.g., luminal epithelium: altrenogest 1.9 ± 1.7%, placebo 23.0 ± 10.5%, P < 0.05). Staining for COX2 (cyclooxygenase-2) was not affected by treatment. In the endometrium a slight but significant increase in the number of PMN (polymorph nuclear neutrophils) was seen in response to treatment (altrenogest 0.8 ± 0.5 PMN/field, placebo 0.3 ± 0.3 PMN/field; P < 0.05). No differences in the relative gene expression of COX2, the receptors for progesterone, estrogens and growth hormone as well as for IGF (insulin-like growth factor) 1 and 2 were detected. The relative gene expression of aquaporin 3 in relation to β-actin differed significantly (P < 0.05) between embryos from altrenogest (3.2 ± 0.8) and placebo-treated mares (1.3 ± 0.2), but no other genes were affected. The study demonstrates down-regulation of progesterone receptors in the endometrium of early pregnant mares by treatment with the progestin altrenogest. This increased expression of aquaporin 3 in the conceptus was not related to changes in embryonic size or development.     

Regulation of expression and role of leukemia inhibitory factor and interleukin-6 in the uterus of early pregnant pigs

Cytokines, which are generally involved in the process of inflammation, may also play a critical role in conceptus implantation. We examined: (1) the expression profiles of leukemia inhibitory factor (LIF) and interleukin (IL)-6 mRNA and their protein content in the endometrium of cyclic and pregnant gilts on Days 10 to 18 after estrus; (2) the effect of conceptus-exposed medium on LIF and IL-6 synthesis in the endometrium; (3) the profiles of IL6R and LIFR mRNA expression in pig conceptuses collected on Days 10 to 18 of pregnancy; and (4) the effect of LIF and IL-6 on the attachment and proliferation of porcine trophoblast cells. The expression of LIF mRNA in the endometrium increased between Days 10 and 12 in both cyclic and pregnant gilts, and tended to be higher in Day 12 pregnant animals compared with nonpregnant ones. The LIF protein content in the uterine lumen peaked on Day 12 of pregnancy, and was higher than on Day 12 of the estrous cycle. Endometrial IL-6 mRNA expression was upregulated on Day 12 in pregnant gilts compared with nonpregnant animals. Moreover, a higher content of IL-6 protein was observed in pregnant than in cyclic gilts. The addition of conceptus-exposed medium resulted in up-regulation of LIF and IL6 mRNA expression, and increased IL-6 content in endometrial slices. In conceptuses, increased mRNA expression was detected on Days 10 to 14 for IL6R and on Day 14 for LIFR, when compared with other days studied. LIF and IL-6 stimulated the attachment and proliferation of trophoblast cells in vitro. In summary, LIF and IL-6 are important components of embryo-uterine interactions during early pregnancy in the pig, and may contribute to successful conceptus implantation.