Sugar-induced changes in cellular and extracellular protein and glycoprotein patterns of sugarbeet cell lines

Plants sense carbohydrates and transduce a signal which changes gene expression and the activities of many enzymes. The relationship between changes in gene expression by carbohydrates and the developmental state of the cells is still poorly understood. To gain more knowledge about this relationship, we have analyzed three sugar beet (Beta vulgaris L.) in vitro cell lines residing on distinct differentiation states. Cell suspensions were initiated and cells were incubated for 72h in the medium with sucrose as a control, or treated during the same period with glucose or 3-O-methylglucose (3OMG). Cellular and extracellular proteins, separated electrophoretically, showed that sugar-induced protein expression was cell line-specific. More differences were visible in extracellular and in glycoprotein than on cellular protein patterns. The 3OMG downregulated while glucose upregulated cellular glycoproteins. In the case of extracellular proteins, glucose and 3OMG were equally effective in both downregulation and upregulation of protein expression. Sialic acid was indicated as a glycan conjugate in sugar beet. Carbohydrate-induced gene expression was related to the developmental state of cells

Sugar-induced changes in cellular and extracellular protein and glycoprotein patterns of sugarbeet cell lines

Plants sense carbohydrates and transduce a signal which changes gene expression and the activities of many enzymes. The relationship between changes in gene expression by carbohydrates and the developmental state of the cells is still poorly understood. To gain more knowledge about this relationship, we have analyzed three sugar beet (Beta vulgaris L.) in vitro cell lines residing on distinct differentiation states. Cell suspensions were initiated and cells were incubated for 72h in the medium with sucrose as a control, or treated during the same period with glucose or 3-O-methylglucose (3OMG). Cellular and extracellular proteins, separated electrophoretically, showed that sugar-induced protein expression was cell line-specific. More differences were visible in extracellular and in glycoprotein than on cellular protein patterns. The 3OMG downregulated while glucose upregulated cellular glycoproteins. In the case of extracellular proteins, glucose and 3OMG were equally effective in both downregulation and upregulation of protein expression. Sialic acid was indicated as a glycan conjugate in sugar beet. Carbohydrate-induced gene expression was related to the developmental state of cells

Receptor binding and degradation of urokinase-type plasminogen activator by human mesangial cells

Receptor binding and degradation of urokinase-type plasminogen activator by human mesangial cells. The binding of [125I] labeled urokinase-type plasminogen activator (u-PA) was studied on human mesangial cells (MC) in culture. The binding of active [125I]u-PA at 37°C reached a plateau after 30 minutes of incubation and remained stable for at least four hours. When the supernatant was analyzed with trichloracetic acid (TCA), TCA soluble radioactive material could be detected after a lag phase of 30 minutes, and then increased linearly for four hours. Analysis by electrophoresis on SDS PAGE and autoradiography of the cell associated radioactivity and of the intracellular content showed that active u-PA and u-PA complexed to plasminogen activator inhibitor type-1 (PAI-1) were bound to the cell surface, but only u-PA/PAI-1 complexes were internalized and degraded. Therefore, the Kd and the number of binding sites were determined by competitive inhibition curves at 4°C using diisopropyl-fluorophosphate (DFP) u-PA. Scatchard plots showed a Kd = 400 ± 30 pM, and Bmax = 240,000 ± 25,000 sites/cell. Excess of the amino terminal fragment of u-PA (ATF) completely blocked the specific binding of [125I]u-PA, confirming that the binding of u-PA was independent of the presence of the active site and/or of the formation of complexes with PAI-1. 3H thymidine incorporation by mesangial cells after stimulation with 100nM active u-PA showed that u-PA had a moderate but significant mitogenic effect, in contrast to inactive u-PA and ATF. However, this mitogenic effect was not accompanied by a proliferative effect. Pretreatment of mesangial cell with a phosphoinositol-specific phospholipase C decreased the binding of [125I]u-PA by 60%, indicating that the majority of the u-PA receptor is anchored in the membrane by a phosphatidylinositol group. These results, together with a positive labeling of MC with monoclonal antibodies to the receptor of U937 cells, and the positive RNA hybridization with the cDNA probe for the human receptor cloned from U937 cells, indicate that the u-PA receptor on mesangial cells is identical to the one of U937 cells. In conclusion, human mesangial cells in culture express a specific receptor for u-PA, which could play a major role in the regulation of u-PA activity by degrading u-PA complexed to PAI-1

Exercise Capacity in Patients With Obstructive Hypertrophic Cardiomyopathy:SEQUOIA-HCM Baseline Characteristics and Study Design

Patients with obstructive hypertrophic cardiomyopathy (oHCM) have increased risk of arrhythmia, stroke, heart failure, and sudden death. Contemporary management of oHCM has decreased annual hospitalization and mortality rates, yet patients have worsening health-related quality of life due to impaired exercise capacity and persistent residual symptoms. Here we consider the design of clinical trials evaluating potential oHCM therapies in the context of SEQUOIA-HCM (Safety, Efficacy, and Quantitative Understanding of Obstruction Impact of Aficamten in HCM). This large, phase 3 trial is now fully enrolled (N = 282). Baseline characteristics reflect an ethnically diverse population with characteristics typical of patients encountered clinically with substantial functional and symptom burden. The study will assess the effect of aficamten vs placebo, in addition to standard-of-care medications, on functional capacity and symptoms over 24 weeks. Future clinical trials could model the approach in SEQUOIA-HCM to evaluate the effect of potential therapies on the burden of oHCM. (Safety, Efficacy, and Quantitative Understanding of Obstruction Impact of Aficamten in HCM [SEQUOIA-HCM]; NCT05186818).</p

African Linguistics in Central and Eastern Europe, and in the Nordic Countries

Non peer reviewe

Malondialdehyde cannot be related to lipoperoxidation in habituated sugarbeet plant cells

International audienceMalondialdehyde (TBARS: thiobarbituric acid reactive substances) has been investigated in non-organogenic and organogenic habituated and normal sugarbeet cell lines and compared with lipid hydroperoxides, conjugated diene formation and lipoxygenase activity in order to estimate the reality of lipid peroxidation processes which have been postulated in the habituated non-organogenic cell line. The results presented here exhibit a strong discrepancy between TBARS and the other indices tested. Neither hydroperoxide index, nor conjugated dienes, nor lipoxygenase activity could confirm that the non-organogenic habituated cells studied were submitted to permanent stress due to free radical attacks. Moreover, these results underlined that the use of TBARS to estimate lipid peroxidation must be considered with extreme caution in plants and can lead to misinterpretations

Effects of Polysaccharide Elicitors on Secondary Metabolite Production and Antioxidant Response in Hypericum perforatum L. Shoot Cultures

The effects of polysaccharide elicitors such as chitin, pectin, and dextran on the production of phenylpropanoids (phenolics and flavonoids) and naphtodianthrones (hypericin and pseudohypericin) in Hypericum perforatum shoot cultures were studied. Nonenzymatic antioxidant properties (NEAOP) and peroxidase (POD) activity were also observed in shoot extracts. The activities of phenylalanine ammonia lyase (PAL) and chalcone-flavanone isomerase (CHFI) were monitored to estimate channeling in phenylpropanoid/flavonoid pathways of elicited shoot cultures. A significant suppression of the production of total phenolics and flavonoids was observed in elicited shoots from day 14 to day 21 of postelicitation. This inhibition of phenylpropanoid production was probably due to the decrease in CHFI activity in elicited shoots. Pectin and dextran promoted accumulation of naphtodianthrones, particularly pseudohypericin, within 21 days of postelicitation. The enhanced accumulation of naphtodianthrones was positively correlated with an increase of PAL activity in elicited shoots. All tested elicitors induced NEAOP at day 7, while chitin and pectin showed increase in POD activity within the entire period of postelicitation. The POD activity was in significantly positive correlation with flavonoid and hypericin contents, suggesting a strong perturbation of the cell redox system and activation of defense responses in polysaccharide-elicited H. perforatum shoot cultures

Secondary metabolite accumulation, antibacterial and antioxidant properties of in vitro propagated Clidemia hirta L. extracts are influenced by the basal culture medium

International audienceClidemia hirta L, a tropical shrub used for traditional medicine in numerous countries, could constitute a new resource of phytochemicals for cosmetic applications. In vitro micro propagation of C. hirta was used to evaluate the influence of different culture media on plant growth, production of phytochemicals, and the antioxidant and antibacterial properties of leaf extracts. Quoirin and Lepoivre medium and Lloyd and McCown's woody plant medium gave the best results. Both production of phytochemicals (i.e., flavonoids, phenolics and saponins) and biological activities were affected by the culture medium composition with the strongest effects for plants cultivated on Quoirin and Lepoivre medium. Strong correlations were shown between the antibacterial activity and the saponin content and between the antioxidant capacity and the flavonoid content. The present study shows how mineral nutrition influences the production of secondary metabolites in C hirta, thus modulating the biological activities of extracts with a view to their possible use in the cosmetic industry. (C) 2016 Academie des sciences. Published by Elsevier Masson SAS