A passage and storage system for isolated bovine endometrial epithelial and stromal cells

To establish a storage system for isolated endometrial cells, we investigated the basal, oxytocin (OT)- and tumor necrosis factor (TNF) alpha-stimulated production of prostaglandin (PG) F(2alpha) in bovine-passaged and frozen-thawed endometrial cells. Stromal and epithelial cells obtained from cows in the early stage of the estrous cycle (Days 2-5) were frozen at -80 C or further cultured and/or passaged until passage 4 in DMEM/Ham's F-12 supplemented with 10% calf serum. A fresh-unfrozen primary culture and one-time passaged fresh-unfrozen cells were used as the control. When both unfrozen and frozen cells reached confluence, the culture medium was replaced with fresh medium with 0.1% BSA and the cells were stimulated with OT (100 ng/ml) or TNFalpha (1 ng/ml) for 4 h. The passage and freezing of the endometrial cells did not affect their morphology. In primary culture of frozen and unfrozen endometrial cells, OT strongly stimulated PGF(2alpha) production in epithelial cells, and TNFalpha strongly stimulated PGF(2alpha) production in stromal cells (P<0.05). The basal output of PGF(2alpha) in frozen stromal cells was similar to that in unfrozen stromal cells. However, the basal output of PGF(2alpha) in frozen epithelial cells was significantly lower than that unfrozen cells (P<0.05). On the other hand, in passaged cells, the basal level of PGF(2alpha) production was retained until passage 1 in epithelial cells, whereas it was retained until passage 4 in stromal cells. Although epithelial cells responded to OT in PGF(2alpha) production until passage 2 (P<0.05), the stromal cells showed a significant response to TNFalpha until passage 4 (P<0.05). These results suggest that stored cells could be used for studying the physiology of bovine endometrium in vitro until passage 1 in endometrial epithelial cells, and until passage 4 in stromal cells.     

成年牛瘤胃上皮细胞原代培养方法研究

为了更加经济便捷,微观科学地研究成年牛瘤胃生理及营养代谢机制,本试验着手建立成年牛瘤胃上皮细胞(ruminal epithelium cell,REC)的原代培养方法,其主要分为瘤胃微生物去除和细胞分离培养两部分。首先用9种不同种类和剂量的抗生素洗涤液,冲洗瘤胃上皮组织。根据微生物去除结果,确定最佳种类和剂量的抗生素洗涤液;然后采用0.25%胰蛋白酶+0.02%EDTA在不同条件下对瘤胃上皮进行连续消化和分步消化以及先用0.1%胶原酶I消化再用0.25%胰蛋白酶+0.02%EDTA在37℃分步消化,根据所得的细胞特征以及细胞增殖活性来确定适合成年牛瘤胃上皮细胞的分离方法。结果表明,瘤胃上皮需分别经过6倍青链霉素和6倍庆大两性霉素洗涤液的清洗后能有效去除瘤胃上皮表面微生物。而瘤胃上皮先经过0.1%胶原酶I消化30min再经0.25%胰蛋白酶+0.02%EDTA分步消化后可获得较多的上皮细胞,且活性较好,分离效果较理想。本试验为成年牛瘤胃上皮细胞的原代培养提供了参考方法。     

Effect of bovine seminal plasma on bovine endometrial epithelial cells in culture

The purpose of this study was to investigate the effect of seminal plasma (SP) from bulls of known fertility on bovine endometrial epithelial cells (bEEC) in culture. The bEEC from passage 5, approximately 5.0–13 × 10⁵ cells per flask, were challenged with SP from bulls of high or low fertility (n = 3 and 2, respectively) or PBS (control), at 1% (75 μl) or 4% (300 μl) and were incubated for 72 hr (n = 13 per challenge). Total cell number and viability of bEEC after challenge with 1% SP from either high‐ or low‐fertility bulls (75H or 75L, respectively) did not differ from controls. In contrast, challenge with 4% of SP from high‐ or low‐fertility bulls (300H or 300L) negatively affected bEEC cell number and viability. Challenge with 300 L had a greater adverse effect than 300H. These results suggest that the negative effect of bovine SP on bEEC is both dose‐dependent and fertility‐dependent.     

Proliferative potential of endometrial stromal cells, and endometrial and placental expression of cyclin in the bovine

The objective of the present investigation was to study proliferative activity of fibroblast-like endometrial stromal cells in bovine endometrial caruncular (CAR) and intercaruncular (ICAR) areas that have distinct functions during implantation. Endometrial stromal cells were derived from CAR and ICAR of nonpregnant cows, and their proliferative potential was analyzed in an in vitro cell culture system. In addition, expression of four types of cell cycle regulatory molecules was analyzed by RT-PCR in samples of CAR, ICAR, cotyledon (COT) and fetal membrane of both artificially inseminated (AI) and somatic nuclear transferred (NT) cows on days 30 and 60 of gestation. The proliferation growth curve showed that the cells derived from CAR had higher proliferative activity than that of ICAR-derived cells. No morphological differences were found between the cells derived from CAR and ICAR at population-doubling levels (PDL) of the two. Most of the cells derived from ICAR of nonpregnant cows exhibited expanded shape with no further proliferation at PDL 6 with a lack of cyclin E expression. Of the regulatory molecules, cyclin D1, CDK2 and CDK4 were expressed in both CAR and ICAR cells derived from both nonpregnant, and AI cows on days 30 and 60 of gestation. The expression of cyclin E in both AI and NT cows was confined to COT and fetal membrane on day 30 of gestation. Cyclin E expression on day 60 of gestation in AI cows was observed in all but ICAR areas. In marked contrast, however, cyclin E expression on day 60 of gestation in NT cows was confined to COT, suggesting that poor placentation in these cows is possibly associated with a lack of cyclin E expression. These results suggest that CAR-derived stromal cells have higher proliferative potential, which may be related to cyclin E expression during implantation.     

Establishment and characterization of a coculture system of equine endometrial epithelial and stromal cells

To investigate the equine endometrium as close to the in vivo situation as possible, we established a coculture system for epithelial and stromal cells (ECs/SCs). ECs and SCs were isolated from nine endometrial tissue specimens. ECs obtained as glandular formations were cultivated on one side of the semipermeable membrane of a Millicell^® insert. After 2 days, SCs (2 × 10⁴ cells/membrane) were seeded onto the other side of the same membrane. During cocultivation, the low serum containing culture medium (Theuß et al., 2010) was supplemented with different concentrations and combinations of 17β‐estradiol (2.0–3.0 pg/ml medium) and progesterone (0.5–15.0 ng/ml medium). Once the cocultures formed continuous cell layers as determined by phase‐contrast microscopy, the membranes were fixed and processed for light microscopical examination. Cytokeratin 19, steroid hormone receptors and the uterine proteins uteroglobin and calbindin_D9k were detected using immunocytochemistry to determine the degree of culture purity and functional cellular differentiation. The culture purity of the EC layer averaged ≥95%. Uteroglobin and calbindin_D9k were consistently expressed in ECs, while hormone receptors were predominantly absent in both cell populations. An explicit cytomorphological epithelial differentiation with formation of round‐oval to polygonal cell forms was encountered in ≤50% of all ECs and independent of supplemented steroids. Based on the findings altogether, and despite the partly absent congruence to the in situ prerequisites, we established a standardized and reproducible coculture system, which offers a basic approach for studies of physiologic and pathophysiologic issues in the mare.     

山羊子宫内膜基质细胞对上皮细胞IL-18分泌活性的调节作用

为了探究性腺激素作用下山羊子宫内膜上皮细胞（EEC）中白细胞介素-18（IL-18）的分泌活性,以及子宫内膜基质细胞（ESC）对其分泌活性的调节作用。基于套皿共培养永生化山羊EEC和ESC为体外研究模型,通过ELISA和Western blot方法检测E2和/或P4对EEC中IL-18分泌水平的作用以及ESC对该作用的影响。ELISA结果显示,E2较无激素对照组可显著增强单独培养EEC中IL-18的分泌水平（P〈0.05）,P4单独或与E2联合作用则进一步增强其分泌活性（P〈0.01）;EEC与ESC共培养模式下,ESC细胞对性激素作用下EEC中IL-18分泌活性具有显著的抑制作用。Western blot结果显示,在单独培养或与ESC共培养模式下,EEC培养上清液中IL-18均以相对分子质量大小18 300的具有生物活性的蛋白形式存在。本研究结果表明,山羊ESC对性腺激素作用下EEC中IL-18的分泌活性具有重要调节作用。     

Fluorometric detection of platelet activating factor receptor in cultured oviductal epithelial and stromal cells and endometrial stromal cells from bovine at different stages of the oestrous cycle and early pregnancy.

During the oestrous cycle and early pregnancy, the oviduct and uterus undergo a variety of morphological and physiological modifications in which the platelet activating factor receptor (PAF-R) plays an important role. PAF-R levels were quantified in bovine oviductal epithelial and stromal cells and endometrial stromal cells at days 2 to 4, 12, and 20 of the estrous cycle and during early pregnancy. Cells were grown in vitro and their intracellular PAF-R concentration was measured by flow cytometry using a polyclonal anti-PAF-R antibody system. A significant increase (P < 0.05) in the portion of PAF-R-positive oviductal epithelial and stromal cells was detected in both non-pregnant and pregnant cattle on days 2 to 4 in comparison to day 12 and 20. In endometrial stromal cells derived from day 20 pregnant bovine, a significant increase (P < 0.05) in PAF-R staining was observed in comparison to the day 20 non-pregnant and days 2 to 4 or 12 pregnant and non-pregnant animals. The PAF-R was detected in oviductal cells by using immunoblotting and immuno-gold postembedding method. Positive binding of the anti-PAF-R antibody was found on the cell membrane and in the cytoplasm. We concluded that the increased PAF-R concentration measured in cultured oviductal epithelial and stromal cells of cyclic and pregnant heifers on days 2 to 4 was hormonally regulated. The increased PAF-R in endometrial stromal cells on day 20 of pregnant heifers was a pregnancy-specific effect and may mediate a local increase in endometrial vascular permeability known to precede the implantation.     

约氏乳杆菌对LPS诱导的奶牛子宫内膜上皮细胞炎症反应的影响

子宫内膜炎是影响奶牛生产的重要疾病之一,该病的有效防控至关重要。本试验探讨了约氏乳杆菌对LPS诱导的奶牛子宫内膜上皮细胞炎症反应的预防作用。约氏乳杆菌悬浮至10~4,10~5,10~6 CFU/mL后,与奶牛子宫内膜上皮细胞共同培养3 h,添加1 mg/L LPS处理3 h,检测趋化因子IL-8和促炎因子TNF-αmRNA、蛋白分泌量和NF-κB信号通路关键蛋白表达量。结果表明,LPS处理奶牛子宫内膜上皮细胞3 h后,IL-8和TNF-αmRNA和蛋白分泌量均显著上升(P0.05), 10~4 CFU/mL约氏乳杆菌预处理后IL-8、TNF-α表达和NF-κB信号通路关键蛋白均显著降低(P0.05),而10~5或10~6 CFU/mL约氏乳杆菌预处理并未影响IL-8和TNF-α表达。结果提示,约氏乳杆菌具有预防奶牛子宫内膜炎的作用,且10~4 CFU/mL表现出良好的抗炎效用。     

Cryopreservation of equine mononuclear cells for immunological studies

A rapid and simple technique for the cryopreservation and recovery of equine mononuclear cells was developed. Buffy-coat leukocytes were frozen in autologous plasma containing 10% DMSO and mononuclear cells were recovered by gradient sedimentation using a standard Ficoll-Hypaque purification procedure. The total numbers of mononuclear cells recovered from cryopreserved samples were 94%-82% of those recovered from fresh blood samples. The functional capabilities of the mononuclear cells from cryopreserved buffy coat preparations were compared with those of mononuclear cells from fresh samples by measuring the ability of cells to proliferate in response to mitogens and specific antigens. Cell-surface antigen expression was measured using monoclonal antibodies in conjunction with flow cytometric techniques and alloantisera in a complement mediated cytotoxicity assay. Cryopreserved mononuclear cells were capable of proliferating normally when stimulated with several mitogens, pokeweed mitogen, phytohemagglutinin and concanavalin A, and a single specific antigen preparation, equine influenza-2 (Equi-2) proteins. The maximum levels of proliferation induced by varying the concentrations of mitogens or the Equi-2 proteins were the same for both the fresh and cryopreserved cells. However, the cryopreserved cells usually required one more day in culture to attain maximum proliferation levels. Flow cytometric analysis of the samples demonstrated that the relative proportions of different lymphocyte populations were not altered by the cryopreservation step. Similarly, MHS alloantigen expression was not altered. The simplicity of the technique coupled with the retained functional properties allows for the cryopreservation of large numbers of leukocytes and the ability to assay various immune functions at a later time.     

In vitro studies of adhesion and invasion by Salmonella strains of bovine epithelial cells

24 Salmonella strains were divided into three groups according to the circumstances of isolation. The adhesion and invasion abilities of the strains were determined using two permanent cell lines (IEC-6, VERO) and an epithelial cell line from the small intestine of a calf fetus (pKD). Strains of different groups showed no differences in their ability to adhere to the cells tested. Significant differences were found for the invasion ability. Strains isolated from organs of calves suffering from salmonellosis showed a significant higher invasiveness for permanent cell lines and a considerable higher invasiveness for pKD cells than strains of the other groups.     

Colostrogenesis: candidate genes for IgG1 transcytosis mechanisms in primary bovine mammary epithelial cells

Bovine colostrogenesis is distinguished by the specific transfer of IgG₁ from the blood to mammary secretions. The process has been shown to be initiated by hormones and occurs during the last weeks of pregnancy when steroid concentrations of estradiol (E₂) and progesterone (P₄) are highly elevated. Rodent intestinal uptake of immunoglobulin G is mediated by a receptor termed Fc fragment of IgG, Receptor, Transporter, alpha (FcGRT) and supported by light chain Beta‐2‐Microglobulin (β2M). We hypothesized that steroid hormone treatments (E₂ and P₄) of bovine mammary epithelial cells in vitro would induce up‐regulation of IgG₁ transcytosis candidate gene mRNA expression suggesting involvement in IgG₁ transcytosis. Two different primary bovine mammary epithelial cell cultures were cultured on plastic and rat tail collagen and treated with hormonal combinations (steroids/lactogenic hormones). Evaluated mRNA components were bLactoferrin (bLf: a control), bFcGRT, β2M, and various small GTPases; the latter components are reported to direct endosomal movements in eukaryotic cells. All tested transcytosis components showed strong expression of mRNA in the cells. Expression of bFcGRT, bRab25 and bRhoB were significantly up‐regulated (p < 0.05) by steroid hormones. bRab25 and bRhoB showed increased expression by steroid treatments, but also with lactogenic hormones. Analysis for the oestrogen receptor (ER) mRNA was mostly negative, but 25% of the cultures tested exhibited weak expression, while the progesterone receptor (PR) mRNA was always detected. bRab25 and bRhoB and likely bFcGRT are potential candidate genes for IgG₁ transcytosis in bovine mammary cells.     

牛乳腺上皮细胞的分离培养

为了对牛乳腺上皮细胞(MECs)进行分离、培养和鉴定,并研究细胞分泌功能,试验通过胶原酶消化法分离得到了牛乳腺上皮细胞,采用传代法对细胞进行纯化,对细胞标志蛋白进行免疫荧光染色鉴定,通过体外诱导和RT-PCR分析鉴定细胞的分泌功能。结果表明:分离到的牛乳腺上皮细胞具有典型乳腺上皮细胞的形态特征,表达广谱角蛋白,经诱导后可分泌β-酪蛋白。     

Adhesion of Staphylococcus aureus and Escherichia coli to bovine udder epithelial cells

An assay for the adhesion of tritiated thymidine-labelled Staphylococcus aureus and Escherichia coli to bovine mammary ductular epithelial cell lines was developed. The relative adhesion of 15 strains of S. aureus to these cell lines was examined. Four strains did not adhere and the remaining 11 adhered at variable levels. Adhesion to different cell lines was generally similar. Adhesion to freshly collected bovine mammary epithelial cells was significantly greater than that to cells maintained in tissue culture. The system described was demonstrated to be a suitable model for studying adhesion of mastitis-causing organisms to bovine mammary epithelial cells.     

Adhesion of Corynebacterium renale and Corynebacterium pilosum to epithelial cells of bovine vulva

Corynebacterium renale and C pilosum adhered effectively to the epithelial cells of the bovine vulva; the numbers of these organisms that adhered to the vulval epithelial cells were 50 and 30/cell, respectively, which were several times as many as those that adhered to the uroepithelial cells. Of the epithelial cells of the vulva, cornified cells lacking nuclei bound more bacteria than did those with indistinct nuclei, indicating that adhesion of bacteria was most effective to the most aged cells. The marked adhesion of C renale and C pilosum to the epithelial cells of the vulva may indicate that the vulva is an important portal of entry of these bacteria.     

Isolation and monolayer culture of bovine oviduct epithelial cells

Oviduct epithelia obtained from 32 cows were cultured. The oviducts were classified into follicular and luteal phases and divided into ampulla and isthmus regions. The epithelial cells were dissociated by enzyme digestion and cultured in plastic dishes with Dulbecco's modified Eagle's medium/Ham's F12 (1:1) containing 10% calf serum. After enzyme treatment, the epithelial suspension showed free ciliated and non-ciliated cells, and cell mass. The non-ciliated cells contained secretory granules in the cytoplasm. The cell mass was composed of ciliated and secretory cells. The cell mass adhered to the dish within 12-24 hr, while the free ciliated cells attached on Day 2 of the culture. The cells grew into confluent monolayers on Day 4. The cell monolayers contained ciliated and non-ciliated cells. The monolayered non-ciliated cells showed a few secretory granules. When the cells were further cultured without subculturing, ciliary activity diminished on Day 5 and was rarely detected on Day 9. When the cells were subcultured on Day 3, ciliary movement was detected on the monolayers for only 2 days. Cell mass that did not adhere to the dish and remained floating in the medium formed ball-like structures on Day 2. Active ciliary beating was observed on the cells that were cultured in the medium supplemented with 10(-5) and 10(-9) M estradiol-17 beta, however, the ciliary activity diminished on Day 5. No difference in the cell growth was observed between the follicular and luteal phases or between the ampulla and isthmus regions.     

Adhesion of Corynebacterium pilosum by pili to epithelial cells of bovine vulva

Piliated (P+) and nonpiliated (P-) clones of Corynebacterium pilosum were selected, and their adhesion to the epithelial cells of the bovine vulva and vaginal vestibule was examined. The number of P+ bacteria of C pilosum that adhered to vulval epithelial cells was greater than that of P- bacteria. The adhesion of P+ bacteria, but not P- bacteria, to the epithelial cells was inhibited by the antipilus antiserum; therefore, the adhesion of C pilosum to the epithelial cells of the vulva was primarily dependent on the pili. The number of C pilosum that adhered to the epithelial cells of the bovine vulva and of the vaginal vestibule increased by decreasing the pH.     

Involvement of stathmin in proliferation and differentiation of immortalized human endometrial stromal cells

Uterine endometrial stromal cells differentiate into decidual cells during the late secretory phase of the menstrual cycle and pregnancy. However, the biochemical mechanisms of decidualization have yet to be definitively elucidated. In the present study, we transfected primary human endometrial stromal cell with a temperature-sensitive mutant of simian virus 40 large T antigen and thereby established an immortalized stromal cell line (EtsT) in order to examine the role of stathmin, a cytosolic phosphoprotein that regulates microtubule dynamics, in stromal cell differentiation. When treated with the decidual stimulus dibutyryl-cAMP (db-cAMP) or forskolin, the fibroblastic cell-shaped EtsT cells transformed into large- and round-shaped cells and secreted large amounts of the decidual markers prolactin (PRL) and insulin-like growth factor binding protein-1 (IGFBP-1). Analysis of the stathmin protein levels in the db-cAMP- and forskolin-treated EtsT cells revealed that the total and phosphorylated protein levels dropped as decidualization progressed. Suppression of stathmin expression by transfection with small interfering RNA (siRNA) suppressed EtsT cell proliferation. It also abolished db-cAMP-induced PRL and IGFBP-1 mRNA expression and protein secretion. Thus, stathmin expression can be considered an integral factor regulating the initial stage of the process of human endometrial stromal cell differentiation.