Abscisic acid (ABA) is a phytohormone involved in fundamental physiological processes of higher plants, such as response to abiotic stress (temperature, light, drought), regulation of seed dormancy and germination, and control of stomatal closure. Here, we provide evidence that ABA stimulates several functional activities [phagocytosis, reactive oxygen species and nitric oxide (NO) production, ...

Phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P(3)) is a key signaling molecule in chemotaxis, a directed cell migration toward chemoattractants. PtdIns(3,4,5)P(3) is transiently generated by chemotactic stimulation and activates reorganization of the actin cytoskeleton at the leading edge of migrating cells. In a recent study, we demonstrated that PtdIns(3,4,5)P(3) directly binds to t...

BACKGROUND Dysfunction of polymorphonuclear leucocytes (PMNLs) in end-stage renal disease (ESRD) patients contributes to a diminished immune defence. The serum levels of leptin are elevated in patients with ESRD. We analysed in vitro effects of leptin on PMNLs from healthy subjects (HS; n = 12) and haemodialysis (HD) patients (n = 15) before and after HD. METHODS PMNL oxidative burst and phag...

Age-related changes in immunity have been shown to highly influence morbidity and mortality. The aim of the present work was to study the effects of environmental enrichment (EE) (8-16 weeks) on several functions and oxidative stress parameters of peritoneal leukocytes, previously described as health and longevity markers, in mice at different ages, namely adult (44 +/- 4 weeks), old (69 +/- 4 ...

Marginated and bone marrow reserve granulocytes were obtained from young healthy volunteers after subcutaneous administration of aqueous epinephrine (0.4 ml/m2) or intravenous administration of hydrocortisone sodium succinate (250 mg), respectively. These leukocytes were compared with circulating granulocytes for the ability to adhere to surfaces, migrate in a random fashion, respond to chemoat...

Blood monocytes are heterogeneous effector cells of the innate immune system. In circulation these cells are constantly in contact with lipid-rich lipoproteins, yet this interaction is poorly characterised. Our aim was to examine the functional effect of hyperlipidaemia on blood monocytes. In the Ldlr(-/-) mouse monocytes rapidly accumulate cytoplasmic neutral lipid vesicles during hyperlipidae...

This paper focuses on the environmental role in morphogenesis in dynamic morphologies (DM). We discuss the benefits of morphological plasticity (MP) and introduce our Environment-Phenotype Map (E-P Map) framework in order to investigate and classify the continual development in DMs and morphologically adaptive behaviour. We present our MP-capable system the Artificial Cytoskeleton (ArtCyto), ho...

Dictyostelium discoideum is a powerful and genetically tractable model system used for the study of numerous cellular molecular mechanisms including chemotaxis, phagocytosis and signal transduction. The past 2 years have seen a significant expansion in the scope and accessibility of online resources for Dictyostelium. Recent advances have focused on the development of a new comprehensive online...

Unicellular eukaryotes have been appreciated as model systems for the analysis of crucial questions in cell and molecular biology. This includes Dictyostelium (chemotaxis, amoeboid movement, phagocytosis), Tetrahymena (telomere structure, telomerase function), Paramecium (variant surface antigens, exocytosis, phagocytosis cycle) or both ciliates (ciliary beat regulation, surface pattern formati...

(project Ro2/012/06) of the University of Muenster and by a grant of the Deutsche Forschungsgemeinschaft (DFG SU 195/3-1). Abstract Monocytes and macrophages may either promote or down-regulate inflammatory reactions depending on their state of activation. The effects of glucocorticoids (GC), the most widely used immunosuppressive drugs, on monocytes are currently not well defined. Analyzing th...