Glycodelin protein and mRNA is downregulated in human first trimester abortion and partially upregulated in mole pregnancy.

Glycodelin (Gd) is a major reproductive glycoprotein and a mediator for immunomodulatory effects directed to cellular, humoral, and innate immunity. Human pregnancy depends on a diversity of physiological processes including modulation of the maternal immunosystem. We evaluated the expression of Gd protein and mRNA in first trimester decidual tissue of normal pregnancies and spontaneous abortion and hydatidiform moles. Furthermore, in vitro experiments on endometrial cancer cells to analyze the effect of human chorionic gonadotropin (hCG) on Gd regulation were performed. In decidual tissue of abortion patients, Gd expression was significantly decreased compared with normal gestation, which was confirmed by in situ hybridization. In mole pregnancy, an upregulation of Gd in the first 8 weeks of pregnancy was present. Gd is a main product of decidual tissue in the first trimester of human pregnancy. Reduced Gd expression in abortive pregnancy could lead to an increased activation of the maternal immunosystem, thus causing rejection of the developing fetus. Moreover, Gd expression in endometrial cancer cells in vitro could be stimulated by addition of hCG. Therefore, we speculate that hCG could be one of the factors regulating Gd expression because hCG is downregulated in women with abortion and upregulated in mole pregnancy. In addition, we found a positive feedback loop in Gd and hCG expression in human pregnancy.     

Interactions Between Rhinanthus minor and Its Hosts: A Review of Water, Mineral Nutrient and Hormone Flows and Exchanges in the Hemiparasitic Association

At the ecological level, the effects of the facultative root hemiparasite Rhinanthus minor on the structure and functioning of its host communities are relative well described; yet until recently, the mechanistic basis for parasitic plant-driven community change and the physiological basis for the host-parasite interaction were poorly understood. Empirical incremental flow models, based on the increase in water, mineral nutrients, carbon assimilates or phytohormones between two defined time points, have been successfully employed to investigate the physiology of resource acquisition by- and distribution within host-parasitic plant associations. In this study we review the application of these empirical flow models to Rhinanthus-host associations showing the extent of and physiological basis of resource abstraction from the host and how this is profoundly influenced by soil nutrient status. We show that Rhinanthus primarily abstracts water and mineral nutrients via the apoplastic pathway through direct lumen-lumen connections with little resource acquisition via symplastic pathways. Nutrient status of the soil is shown to significantly influence the resource acquisition. We also investigate the hormonal regulation of resource acquisition by Rhinanthus showing pivotal roles for the key for the phytohormones abscisic acid (ABA) and cytokinins.     

Immunohistochemistry,glycosylation and immunosuppression of glycodelin in human ovarian cancer

Glycodelins (Gds) are glycoproteins with a gender specific glycosylation. Glycodelin A (GdA) is primarily produced in endometrial and decidual tissue and secreted to amniotic fluid. Glycodelins were also identified in several cancer types, including serous ovarian cancer. Gds act as a T-cell inhibitor and are involved in inactivation of human monocytes. With a Gd peptide antibody, derived from a 15 amino acid sequence of human Gd and in situ hybridization experiments, the expression of Gd in serous, mucinous, endometrioid and clear cell ovarian tumors was identified. In contrast to former investigations with antibodies against GdA, a positive immunohistochemical reaction for Gd was observed in all forms of epithelium ovarian cancer. These results were confirmed with in situ hybridization. In addition, Gd is expressed in granulose cell tumors, a non-epithelial form of ovarian cancer. Furthermore, Gd was purified from ascites fluid of ovarian cancer patients. Ascites Gd showed significant differences in its structure of sialyl Lewis-type oligosaccharides compared to GdA. Additionally, ascites Gd inhibits IL-2 stimulated proliferation of peripheral blood leucocytes and inhibits adhesion of SLe^X-positive cells to E-selectin. Therefore, Gd could act as an inhibitor of lymphocyte activation and/or adhesion in ovarian cancer. U. Jeschke, I. Mylonas and C. Kunert-Keil contributed equally to this work.     

Growth of Zea mays L. plants with their seminal roots only. Effects on plant development, xylem transport, mineral nutrition and the flow and distribution of abscisic acid (ABA) as a possible shoot to root signal

Maize (Zea mays L.) was grown in quartz sand culture eitherwith a normal root system (controls) or with seminal roots only(‘single-rooted’). Development of adventitious rootswas prevented by using plants with an etiolated mesocotyl andthe stem base was positioned 5–8 cm above the sand. Eventhough the roots of the single-rooted plants were sufficientlysupplied with water and nutrients, the leaves experienced waterdeficits and showed decreased transpiration as trans plrationalwater flow was restricted by the constant number of xylem vesselspresent in the mesocotyl. As a consequence of this restriction,transpirational water flow velocities in the metaxylem vesselsreached mean values of 270 m h^–1 and phloem transportvelocities of 5.2 m h^–1. Despite limited xylem transportmineral nutrient concentrations in leaf tissues were not decreasedin single-rooted plants, but shoot and particularly stem developmentwas somewhat inhibited. Due to the lack of adventitious rootsthe shoot:root ratio was strongly increased in the single-rootedplants, but the seminal roots showed compensatory growth comparedto those in control plants. Consistent with decreased leaf conductance,ABA concentrations in leaves of single-rooted plants were elevatedup to 10-fold, but xylem sap ABA concentrations in these plantswere lower than in controls, in good agreement with the well-wateredconditions experienced by the seminal roots. Surprisingly, however,ABA concentrations in tissues of the seminal roots of the single-rooted plants were clearly increased compared to the controls,presumably due to increased ABA import via phloem from the water-stressedleaves. The results are discussed in relation to the role ofABA as a shoot to root signal. Key words: Zea mays, seminal roots, plant development, xylem transport, mineral nutrition, ABA, shoot-to-root signal     

Über die Aufnahme von Phosphat-und Sulfationen Durch Blätter von Elodea Densa und Ihre Beeinflussung Durch Licht,Temperatur und Aussenkonzentration

Zusammenfassung An Elodea densa wurde die Aufnahme von Phosphat-und Sulfationen im Konzentrationsbereich zwischen 10^-8 und 5×10^-3 m bei Temperaturen zwischen 2 und 18°C im Licht und im Dunkeln untersucht. Die Phosphataufnahme wurde in den Fraktionen anorganisches Phosphat (P_i), TCA-lösliche labile (P_lo) sowie stabile (P_so) organische Phosphorsäureverbindungen und TCA-unlösliche Verbindungen (P_u) untersucht. Die Hauptmenge des aufgenommenen Phosphates findet sich unter allen Bedingungen, besonders aber bei niedrigem pH, tiefen Temperaturen oder hohen Phosphatkonzentrationen in der P_i-Fraktion.Licht fördert die H₂PO₄^--Aufnahme und den Einbau von Phosphat in die einzelnen Fraktionen, am stärksten bei den Fraktionen P_u und P_so, weniger bei P_lo, am wenigsten bei P_i. Die Lichtförderung der H₂PO₄^--Aufnahme hat ein Maximum bei mittleren Konzentrationen, sie nimmt mit fallender Temperatur ab.Licht fördert dienfalls die SO₄^--Aufnahme, auch hier tritt ein Maximum bei mittleren Konzentrationen auf, mit fallender Temperatur wird die Lichtförderung jedoch größer.Die Konzentrationsabhängigkeit der Aufnahme der beiden Anionen weist komplexe Isothermen auf, die einander sehr ähnlich sind. Die Isothermenform bei höherer und tiefer Temperatur ist weitgehend gleich.Die Temperaturabhängigkeit gehorcht innerhalb eines beschränkten Temperaturbereiches einer Arrheniusbeziehung. Die Aktivierungsenergien der Phosphat-und Sulfationenaufnahme zeigen ein Maximum bei mittleren Konzentrationen, ihre Werte sind hier etwa 15,8±2,9 bzw. 24,8±2,8 kcal/mol. Die Aktivierungsenergie des Phosphateinbaues ist bei den Fraktionen P_u und P_so am größten, kleiner bei P_lo und P_i.Energetischen Betrachtungen zufolge kann die Nettoaufnahme der beiden Anionen im gesamten Konzentrationsbereich nur endergonisch und somit aktiv erfolgen.Aufgrund der Veränderung der Lichtwirkung und der Aktivierungsenergien mit der Konzentration werden drei Bereiche der Konzentrationsabhängigkeit unterschieden, in denen folgende Vorgänge als geschwindigkeitsbestimmend bei der Bruttoaufnahme angesehen werden: bei niedrigen Konzentrationen Diffusion in der nichtgerührten Schicht (Filmkinetik), bei mittleren Konzentrationen die aktive Aufnahme und bei hohen Konzentrationen die aktive sowie eine passive Aufnahme durch Diffusion.Dieser Interpretation zufolge werden bei einer Konzentration von 5×10^-3 m die Bruttoaufnahme in ihre Anteile aufgeteilt und die Werte des passiven und des aktiven Influxes sowie der Permeabilitätskoeffizienten abgeschätzt. Die Aktivierungsenergie des passiven Transportes ergibt sich dann zu 5 bzw. 8 kcal/mol bei H₂PO₄^-bzw. SO₄^--.Die Übereinstimmung der Aktivierungsenergien der Aufnahme von Phosphat in die P_lo-und die P_i-Fraktion wird als ein Hinweis dafür interpretiert, daß möglicherweise ATP an der Phosphationenaufnahme beteiligt ist.

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On the uptake of phosphate and sulphate ions by leaves of Elodea densa as influenced by light, temperature and external concentrations

Summary Using ³²P and ³⁵S as tracers the uptake of phosphate and sulphate anions by Elodea densa has been studied in external concentrations of 10^-8 to 5×10^-3 m at varying temperatures between 2 and 18°C and under different conditions of light. The uptake of phosphate was investigated in the fractions inogranic phosphate (P_i), TCA-soluble acid-labile organic phosphate (P_lo), TCA-soluble stabile organic phosphate (P_so) and TCA-insoluble phosphate (P_u). The main portion of the phosphate taken up was found in the P_i fraction under all conditions, but especially under conditions of low pH, low temperatures and high phosphate concentration.In the case of phosphate light was found to increase the overall uptake at intermediary concentrations, the stimulation being greatest in the fractions P_so and P_u, less in P_lo and least in P_i. At high and low concentrations the stimulation by light disappeared. At low temperatures the stimulation was considerably smaller, but it showed the same dependence on external concentration and even became negative at low concentrations.Light stimulates the uptake of sulphate, too, the stimulation being dependent on external concentration in the same way as it is with phosphate. However, at low temperatures this stimulation of sulphate uptake by light is considerably higher than at high temperatures.Variation of external concentrations of phosphate and sulphate ions results in similar isotherms of uptake for both anions. The isotherms exhibit a linear dependence at low concentrations, a saturation curve at intermediary concentrations and a further rise at high concentrations. Using enzyme kinetics one obtains hyperbolic curves indicating that at least two different processes are taking place.The dependence on temperature within a limited range can be approximated by an Arrhenius equation and is described by the apparent energies of activation E_app which are found to be 15.8±2.9 and 24.8±2.8 kcal/mol for the phosphate and sulphate uptake respectively at intermediary concentrations. In the case of phosphate E_app is higher for the incorporation into P_u and P_so and considerably lower but very similar for both the incorporation into P_lo and P_i. In this respect E_app parallels the stimulation by light.The energies of activation of uptake for both anions are strongly dependent on external concentration and reach a maximum at intermediary concentrations.Considering the energetics with respect to internal and external concentrations and the value of the membrane potential, net uptake of both ions must occur with an expenditure of free energy, thus representing an active process in the whole range of external concentrations.However, from the concomitant changes in the stimulation by light and the energies of activation, the isotherms of uptake are interpreted as being composed of three concentration ranges with the following steps being rate-limiting: the diffusion in the unstirred layer at low concentrations, the active uptake at intermediary concentrations and a considerable contribution of diffusive influx at high external concentrations. This diffusive uptake can occur with tracer flux (influx) only, not with net uptake. Thus it is not contradictory to the energetics of anion uptake.On the basis of this interpretation active and passive fluxes at high concentration are separated and permeability coefficients are estimated from the passive fluxes. According to this sparation the energies of activation of diffusive transport in the cellular membrane are calculated as 5 and 8 kcal/mol (Q₁₀=1.35 or 1.6) for phosphate and sulphate respectively. The phosphate fluxes are considerably higher than the sulphate fluxes.From the values of E_app it is deduced that a major component of P_lo, possibly ATP, might participate in active phosphate uptake.The isotherms compare well with isotherms of anion uptake by other species so that the results may have some bearing on the interpretation of anion uptake in general.

     

Effect of top excision and replacement by 1-naphthylacetic acid on partition and flow of potassium in tobacco plants

The effect of removal of the shoot apex of 92-d-old tobacco plants and its replacement by 1-naphthylacetic acid (NAA) on sink-source relationships and on the flows and partitioning of potassium and water has been studied over a short-term period of 7 d (intact control plants) or 8 d (decapitated and NAA-treated plants). For determining flows an upper, middle and lower stratum of three leaves each were analysed. Within the study period three new leaves were formed in control plants and 57.7% of the total dry matter increment during the experimental period was allocated to the apex and these newly formed leaves. An even higher proportion of the K+ taken up (93.8%) was deposited in these organs and this was imported via xylem (72%) and phloem (28%). Only 18.7% and 9.8% of the total dry matter increment were found in the previously present upper leaves and the roots, respectively, and substantial net K+ export occurred from middle and lower leaves and roots. Decapitation removed the dominant phloem sink and caused marked changes in sink-source relationships. After decapitation the net increase in root dry matter was twice that of control plants. 56.2% of the total net increments in dry matter and 70% of the absorbed K+ were deposited in upper leaves (below the excised apex). There was only slight net K+ export from the middle leaves. Application of NAA on the cut surface of the stem stump did not change the growth of plants that much, apart from a substantial increase in stem growth, correspondingly it stimulated the partitioning of K+ into the upper leaves and most dramatically into the stem, which deposited 64.5% or 27% of the K+ uptake, respectively. In these plants K+ uptake was increased and the K+ concentrations in upper, middle and lower leaves were increased from 4.7, 5.4 and 5.6 to 5.1, 6.1 and 6.1% of dry matter, respectively. Possible mechanisms of this effect of NAA on the improvement of K+ concentration in tobacco leaves are discussed in detail.     

Measurement of hepatic protein fractional synthetic rate with stable isotope labeling technique in thapsigargin stressed HepG2 cells

Severe burn-induced liver damage and dysfunction is associated with endoplasmic reticulum (ER) stress. ER stress has been shown to regulate global protein synthesis. In the current study, we induced ER stress in vitro and estimated the effect of ER stress on hepatic protein synthesis. The aim was two-fold: (1) to establish an in vitro model to isotopically measure hepatic protein synthesis and (2) to evaluate protein fractional synthetic rate (FSR) in response to ER stress. Human hepatocellular carcinoma cells (HepG2) were cultured in medium supplemented with stable isotopes 1,2-(13)C(2)-glycine and L-[ring-(13)C(6)]phenylalanine. ER stress was induced by exposing the cells to 100 nM of thapsigargin (TG). Cell content was collected from day 0 to 14. Alterations in cytosolic calcium were measured by calcium imaging and ER stress markers were confirmed by Western blotting. The precursor and product enrichments were detected by GC-MS analysis for FSR calculation. We found that the hepatic protein FSR were 0.97 ± 0.02 and 0.99 ± 0.05%/hr calculated from 1,2-(13)C(2)-glycine and L-[ring-(13)C(6)]phenylalanine, respectively. TG depleted ER calcium stores and induced ER stress by upregulating p-IRE-1 and Bip. FSR dramatically decreased to 0.68 ± 0.03 and 0.60 ± 0.06%/hr in the TG treatment group (p<0.05, vs. control). TG-induced ER stress inhibited hepatic protein synthesis. The stable isotope tracer incorporation technique is a useful method for studying the effects of ER stress on hepatic protein synthesis.