Exogenous genistein in late gestation: effects on fetal development and sow and piglet performance.

Due to their functional similarity to estradiol, phytoestrogens could prove to be beneficial in late gestating sows. The goal of this study was to determine the impact of providing the phytoestrogen genistein during late pregnancy on the performance of sows and their litters. In total, 56 gilts were equally divided into the two following groups on day 90 of gestation: (1) controls (CTL); and (2) two daily i.m. injections of 220 mg of genistein (GEN). Treatments were carried out until farrowing. Jugular blood samples were collected from 16 gilts/treatment on days 89 and 110 of gestation, and on days 3 and 21 of lactation. Milk samples were also obtained from those sows on day 3 of lactation. A male piglet from 16 CTL and 15 GEN litters was slaughtered at 24 h postpartum and a blood sample was obtained. The liver, heart and visceral organs were weighed and the semitendinosus (ST) muscle was collected and carcass composition was determined. The treatment increased (P0.1) on weight or backfat loss of sows during lactation, milk composition or weights of piglets. The pre-weaning mortality rate of piglets was very low (0.1). However, carcasses from GEN litters contained more fat than those from CTL litters (9.63% v. 8.34%, P0.1). In conclusion, injecting gilts with 440 mg/day of genistein in late gestation increased IGF1 concentrations in gilts and carcass fat in neonatal piglets, but had minimal effect on muscle development of piglets at birth and on the performance of lactating sows and their litters.

Regulation of soy isoflavones on weight gain and fat percentage: evaluation in a Chinese Guangxi minipig model.

This study was conducted to determine the effects of soy isoflavones on changes in body and tissue weight and on insulin-like factor I (IGF-I) and peroxisome proliferator-activated receptor-γ (PPARγ) gene and protein expression in muscle and adipose tissues in Chinese Guangxi minipig, as a model for studying human nutrition. A total of 72 male Chinese Guangxi minipigs were fed basal diet (control, Con), low dose of soy isoflavones and high dose of soy isoflavones (HSI). The results showed that HSI increased the body weight (BW) gain and fat percentage of minipigs (P < 0.05). In addition, the serum concentrations of IGF-I and interleukin-6 were increased by high levels of soy isoflavones (P < 0.05). Furthermore, a diet containing soy isoflavones enhanced IGF-I mRNA expression levels in longissimus muscle, but decreased these levels in perirenal fat. However, the mRNA and protein expression levels of PPARγ in longissimus muscle and subcutaneous adipose tissue were both increased when compared with the Con. The data indicated that soy isoflavones regulated the BW gain and fat percentage of Chinese Guangxi minipigs, which also showed changes in IGF-I system and PPARγ. However, further research is required to clarify the causative relationship.

Enhancement of immune responses to infectious bursal disease vaccine by supplement of an extract made from Momordica cochinchinensis (Lour.) Spreng. seeds.

The immunological effect of an extract from Momordica cochinchinensis seed (ECMS) on immune responses against infectious bursal disease (IBD) in chickens was evaluated. Fifty-two birds were equally divided into 4 groups and immunized with inactivated IBD vaccine alone (controls) or IBD vaccine emulsified with ECMS (20, 40, and 80 microg). Serum IgG antibody levels against IBD and BW were measured on 0, 7, 14, 21, 28, and 35 d after immunization. The ELISA results revealed that the chickens that received 20 microg of ECMS had significantly enhanced antibody levels on 14, 21, 28, and 35 d when compared with controls (P<0.05). A significant increase in mitogenic stimulated lymphocyte proliferation was also recorded in all ECMS groups as compared with controls (P<0.05; P<0.01). No adverse effect of ECMS was noted on growth performance, although average weight gain was significantly higher in 20 microg (7, 14, 21, 28, and 35 d) and 40 or 80 microg (14 d) of ECMS groups as compared with controls (P<0.05; P<0.01). Further studies are suggested for the investigation of immunological effects of ECMS.

Contrasting net primary productivity and carbon distribution between neighboring stands of Quercus robur and Pinus sylvestris.

Standing biomass, net primary production (NPP) and soil carbon (C) pools were studied in a 67-year-old pedunculate oak (Quercus robur L.) stand and a neighboring 74-year- old Scots pine (Pinus sylvestris L.) stand in the Belgian Campine region. Despite a 14% lower tree density and a lower tree height in the oak stand, standing biomass was slightly higher than in the pine stand (177 and 169 Mg ha(-1) in oaks and pines, respectively), indicating that individual oak trees contained more biomass than pine trees of similar diameter. Moreover, NPP in the oak stand was more than double that in the pine stand (17.7 and 8.1 Mg ha(-1) year(-1), respectively). Several observations indicated that soil organic matter accumulated at higher rates under pines than under oaks. We therefore hypothesized that the pines were exhibiting an age-related decline in productivity due to nutrient limitation. The poor decomposability of pine litter resulted in the observed accumulation of organic matter. The subsequent immobilization of nutrients in the organic matter, combined with the already nutrient-poor soil conditions, resulted in a decrease in total NPP over time, as well as in a substantial shift in the allocation of NPP toward fine roots. In the oak stand, litter is less recalcitrant to decay and soil acidity is less severe; hence, organic matter does not accumulate and nutrients are recycled. This probably explains why NPP was much higher in the oaks than in the pines and why only a small proportion of NPP was allocated to oak fine roots.

Effect of different water supply on morphology, growth and physiological characteristics of Salix psammophila seedlings in Maowusu sandland, China.

Response pattern was investigated for seedlings of Salix psammophila, a dominant shrub in Maowusu sandland, to the simulated precipitation change by artificially controlling water supply at four levels. The growth characters, in terms of plant height, stem diameter, total branch number, total leaf number and area, total bifurcation ratio, total branch length and branch number, branch length, leaf number and leaf area of each branch order, and leaf, branch and root biomass significantly increased when water supply increased. That water supply had significant effect on biomass allocation showed different investment pattern of biomass resource of the seedlings grown under different water supply treatments. Stomatal density of abaxial leaf surface decreased, and stomatal apparatus length and width of adaxial and abaxial leaf surface increased with the increase of water supply, while Stomatal density of adaxial leaf surface was not affected by water supply. Water supply obviously affected the diurnal changes of photosynthetic rate, and the photosynthetic rate of the seedlings showed strongly midday depression grown under the 157.5 mm water supply, but not grown under higher water supply. Additionally the assimilation-light response curves and fluorescence efficiency more showed that water supply improve photosynthesis capacity. Finally, S. psammophila seedlings stood out by their slow growth and relatively high investments in root growth in order to reduce tissue losing rate and consumption of water resource for keeping water balance under water stress. The seedlings that grown under rich water supply did by their fast growth and relatively high investments in branch and leaf growth in order to improve the power of capturing light energy for higher photosynthesis.

Nuclear factor-kappaB-mediated X-linked inhibitor of apoptosis protein expression prevents rat granulosa cells from tumor necrosis factor alpha-induced apoptosis.

Although X-linked inhibitor of apoptosis protein (Xiap) is an important intracellular suppressor of apoptosis in a variety of cell types and is present in ovary, its physiological role in follicular development remains unclear. The purpose of the present studies was to examine the modulatory role of Xiap in the proapoptotic action of tumor necrosis factor-alpha (TNFalpha) in rat granulosa cells. Granulosa cells from equine CG-primed immature rats were plated in RPMI 1640 medium containing 10% FCS and subsequently cultured in serum-free RPMI in the absence or presence of TNFalpha (20 ng/ml), the protein synthesis inhibitor cycloheximide (10 microM), and/or adenoviral Xiap sense or antisense complementary DNA. TNFalpha alone failed to induce granulosa cell death, but in the presence of cycloheximide, it markedly increased the number of apoptotic granulosa cells (as assessed by in situ terminal deoxynucleotidyl transferase-mediated deox-UTPbiotin end labeling and DNA fragmentation analysis). Western analysis indicated that TNFalpha alone increased the Xiap protein level, a response significantly reduced by adenoviral Xiap antisense expression. Down-regulation of Xiap expression by antisense complementary DNA induced granulosa cell apoptosis, which was potentiated by the cytokine. Inhibition of nuclear factor-kappaB activation by N-acetyl-cysteine and SN50 suppressed Xiap protein expression and enhanced apoptosis induced by TNFalpha. The latter phenomenon was readily attenuated by adenoviral Xiap sense expression. In conclusion, these findings suggest that Xiap is an important intracellular modulator of the TNFalpha death signaling pathway in granulosa cells. Its expression is regulated by the TNFalpha via a nuclear factor-kappaB-mediated mechanism.

Mammalian follicular development and atresia: role of apoptosis.

The regulation of follicular development and atresia is a complex process and involves interactions between endocrine factors (gonadotropins) and intraovarian regulators (sex steroids, growth factors and cytokines) in the control of follicular cell fate (i.e. proliferation, differentiation and programmed cell death). Granulosa and theca cells are key players in this fascinating process. As atresia is the fate of most follicles, understanding of how these physiological regulators participate in determining the destiny of the follicle (to degenerate or to ovulate) at cellular and subcellular levels is fundamental. This short review summarizes the role of intraovarian modulators of programmed cell death in the induction of atresia during follicular development.

Apoptosis and chemoresistance in human ovarian cancer: is Xiap a determinant?

Cisplatin-induced apoptosis in epithelial ovarian cancer cells is in part a consequence of suppressed Xiap expression and upregulation of the Fas/FasL system. Changes in the expression of these 'cell death' and 'cell survival' genes lead to activation of caspase-3, and cleavage of MDM2 and FAK. Failure of cancer cells to maintain a balance in the expression of these genes in favor of apoptotic cell death may be an important factor of chemoresistance. Xiap may be a novel target for gene therapy of human ovarian epithelial cancer and, dependent on P53 status, expression of Xiap antisense alone or in combination with wild-type P53 sense may offer a new approach for the treatment of the chemoresistant cancer.

Hormonal regulation of oestrogen and progesterone receptors in cultured bovine endometrial cells.

Changes in the number of progesterone and oestradiol receptors in the endometrium are thought to play a role in the induction of luteolysis. The effect of oestradiol and progesterone on the regulation of their receptors in cultured bovine uterine epithelial and stromal cells was examined to determine the mechanisms involved in this process. Cells were obtained from cows at days 1-3 of the oestrous cycle and were cultured for 4 or 8 days in medium alone (RPMI medium + 5% (v/v) charcoal-dextran stripped newborn calf serum) or with oestradiol, progesterone or oestradiol and progesterone. At the end of culture, receptor binding was measured by saturation analysis. Specific binding of both [3H]ORG 2058 (16 alpha-ethyl-21-hydroxy-19-nor (6,7-3H) pregn-4-ene-3,20-dione) and [3H]oestradiol to epithelial and stromal cells showed high affinities (Kd = 1.1 x 10(-9) and 6 x 10(-10) mol l-1, respectively, for progesterone receptors; Kd = 5.5 x 10(-9) and 7 x 10(-10) mol l-1, respectively, for oestradiol receptors). In the stromal cells, oestradiol (0.1-10 nmol l-1) increased the number of oestradiol receptors from 0.21 +/- 0.06 to 0.70 +/- 0.058 fmol microgram-1 DNA and the number of progesterone receptors from 1.4 +/- 0.83 to 6.6 +/- 0.70 fmol microgram-1 DNA in a dose-dependent manner after 4 days of culture (P < 0.01). After culture for 8 days, the stimulatory effect of oestradiol increased. Progesterone (50 nmol l-1) had no effect on the number of oestradiol or progesterone receptors (P > 0.05). However, progesterone inhibited the stimulatory effect of oestradiol. In epithelial cells, the lower concentrations of oestradiol (0.1 and 1 nmol l-1) stimulated the number of progesterone receptors (P = 0.05) after 4 days culture, whereas the highest concentration of oestradiol (10 nmol l-1), progesterone (50 nmol l-1) and progesterone (50 nmol l-1) plus oestradiol (1 nmol l-1) had no effect. After culture for 8 days, the stimulatory effect of oestradiol decreased. In contrast to progesterone receptors, the number of oestradiol receptors increased with oestradiol concentration (P < 0.01). These data show that the number of progesterone receptors was higher in the stromal cells than in epithelial cells, whereas the number of oestradiol receptors was higher in the epithelial cells than in stromal cells. Oestradiol upregulates its own receptor and increases the number of progesterone receptors in both cell types in vitro, whereas progesterone has little effect, but inhibits the effects of oestradiol on progesterone receptors.

Down-regulation of oxytocin-induced cyclooxygenase-2 and prostaglandin F synthase expression by interferon-tau in bovine endometrial cells.

Oxytocin (OT) is responsible for the episodic release of luteolytic prostaglandin (PG) F2alpha from the uterus in ruminants. The attenuation of OT-stimulated uterine PGF2alpha secretion by interferon-tau (IFN-tau) is essential for prevention of luteolysis during pregnancy in cows. To better understand the mechanisms involved, the effect of recombinant bovine IFN-tau (rbIFN-tau) on OT-induced PG production and cyclooxygenase-2 (COX-2) and PGF synthase (PGFS) expression in cultured endometrial epithelial cells was investigated. Cells were obtained from cows at Days 1-3 of the estrous cycle and cultured to confluence in RPMI medium supplemented with 5% steroid-free fetal calf serum. The cells were then incubated in the presence or absence of either 100 ng/ml OT or OT+100 ng/ml rbIFN-tau for 3, 6, 12, and 24 h. OT significantly increased PGF2alpha and PGE2 secretion at all time points (p < 0.01), while rbIFN-tau inhibited the OT-induced PG production and reduced OT receptor binding in a time-dependent manner. OT increased the steady-state level of COX-2 mRNA, measured by Northern blot, which was maximal at 3 h (9-fold increase) and then decreased with time (p < 0.01). OT also caused an increase in COX-2 protein, which peaked at 12 h (11-fold increase), as measured by Western blot. Addition of rbIFN-tau suppressed the induction of COX-2 mRNA (89%, p < 0.01) and COX-2 protein (50%, p < 0.01) by OT. OT also increased PGFS mRNA, and this stimulation was attenuated by rbIFN-tau (p < 0.01). To ensure that the decrease in COX-2 was not solely due to down-regulation of the OT receptor, cells were stimulated with a phorbol ester (phorbol 12-myristate 13-acetate; PMA) in the presence and absence of rbIFN-tau. The results showed that rbIFN-tau also decreased PMA-stimulated PG production and COX-2 protein. It can be concluded that rbIFN-tau inhibition of OT-stimulated PG production is due to down-regulation of OT receptor, COX-2, and PGFS.

Differential effects of oestradiol and progesterone on proliferation and morphology of cultured bovine uterine epithelial and stromal cells.

The effect of oestrogen and progesterone on the proliferation of cultured bovine uterine epithelial and stromal cells was assessed. Epithelial and stromal cells recovered from cows at day 1 to day 3 of the oestrous cycle were cultured in RPMI medium supplemented with 5% steroid-free fetal calf serum for 4 and 8 days. The addition of progesterone to the culture medium altered the morphology of stromal cells. Oestradiol (0.1-10 nmol l-1) and progesterone (50 nmol l-1) significantly increased the total DNA (from 9.6 +/- 0.96 to 25.6 +/- 0.99 micrograms per well, P < 0.001) and protein content (from 76.6 +/- 2.6 to 125.8 +/- 2.6 micrograms per well, P < 0.001) and decreased the ratio of protein to DNA (from 8.0 +/- 0.24 to 4.9 +/- 0.24, P < 0.01) in stromal cells during the first 4 days. During the second 4 days, the relative percentages of increase in DNA content were not affected by steroids, indicating that the major effect of steroids on stromal cell proliferation was exerted during the first 4 days of incubation. The morphology of epithelial cells was not influenced by the addition of steroids. DNA content of epithelial cells was reduced by the addition of oestrogen (from 22.9 +/- 2.1 to 15.0 +/- 2.0 micrograms per well, P < 0.01), but not progesterone (from 22.9 +/- 2.1 to 25.8 +/- 2.0 micrograms per well, P > 0.05). Total protein content of epithelial cells was reduced by oestradiol by day 4 (from 111.0 +/- 6.2 to 71.0 +/- 6.2 micrograms per well, P < 0.01), but not by day 8 (from 305.0 +/- 10.5 to 296.0 +/- 10.5 micrograms per well, P > 0.05). Progesterone increased the total protein content (from 305.0 +/- 10.5 to 366.0 +/- 10.5 micrograms per well, P < 0.01). Oestradiol significantly enhanced the ratio of protein to DNA in epithelial cells at day 8 (from 10.1 +/- 1.0 to 16.8 +/- 1.0, P < 0.01). These results show that oestradiol and progesterone have different effects on the proliferation and morphology of epithelial and stromal cells in vitro.

Regulation of cyclooxygenase-2 and prostaglandin F synthase gene expression by steroid hormones and interferon-tau in bovine endometrial cells.

Estradiol (E2) and progesterone are responsible for regulating PG synthesis in the endometrium during the estrous cycle and interferon-tau (IFN-tau) alters PG synthesis during early pregnancy in ruminants. In this study, we examined the effects of these steroid hormones and recombinant bovine IFN-tau (rbIFN-tau) on PG production and on cyclooxygenase-2 (COX-2) and PG F (PGF) synthase (PGFS) gene expression in isolated endometrial cells. E2 decreased both PGF2alpha and PG E2 (PGE2) whereas progesterone increased PGF2alpha secretion in epithelial cells. Steroid hormones had no effect on PG production in stromal cells. rbIFN-tau attenuated both PGF2alpha and PGE2 production in epithelial cells and enhanced their production, and the ratio of PGE2 to PGF2alpha, in stromal cells. Northern blot analysis showed that E2 and rbIFN-tau decreased COX-2 messenger RNA (mRNA) levels in epithelial cells. Conversely, rbIFN-tau increased COX-2 mRNA in stromal cells. Furthermore, rbIFN-tau decreased PGFS mRNA in both cell types and this was associated with the increase in PGE2/PGF2alpha ratio. These results show that the regulation of PG synthesis by steroid hormones is different in endometrial epithelial and stromal cells in vitro. The attenuation of PGF2alpha secretion from epithelial cells and increased PGE2 production in stromal cells by rbIFN-tau are modulated by steroid hormones.