Astrid Kehlen

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Because of their abundance, resistance to proteolysis, rapid aggregation and neurotoxicity, N-terminally truncated and, in particular, pyroglutamate (pE)-modified Abeta peptides have been suggested as being important in the initiation of pathological cascades resulting in the development of Alzheimer's disease. We found that the N-terminal pE-formation is(More)
Membrane peptidases are a multifunctional group of ectoenzymes that have been implicated in the control of growth and differentiation of many cellular systems. Here, using aminopeptidase N/CD13 as an example, Dagmar Riemann and colleagues discuss the role of cell-cell contact in peptidase regulation and the influence of peptidases on cellular functions.
Information on the regulation of steroid hormone receptors and their distinct functions within the human endometrial epithelium is largely unavailable. We have immortalized human primary endometrial epithelial cells (EECs) isolated from a normal proliferative phase endometrium by stably transfecting the catalytic subunit (hTERT) of the human telomerase(More)
Interleukin-17 (IL-17) has been characterized as a proinflammatory cytokine produced by CD4+ CD45RO+ memory T cells. Overproduction of IL-17 was detected in the synovium of patients with rheumatoid arthritis (RA) compared to patients with osteoarthritis. In contrast to the restricted expression of IL-17, the IL-17 receptor (IL-17R/CDw217) is expressed(More)
Aminopeptidase N (APN) and dipeptidylpeptidase IV (DPIV) are transmembrane type II molecules widely distributed in mammalian tissues. In recent years, the interest in cell surface peptidases has increased considerably because, among other things, several reports indicate roles of ectopeptidases in tumour cell metastasis. Investigations into the regulation(More)
Self-renewal is considered as a common property of stem cells. Dysregulation of stem cell self-renewal is likely a requirement for the development of cancer. Hiwi, the human Piwi gene, encodes a protein responsible for stem cell self-renewal. In this study, we investigated the expression of Hiwi at the RNA level by real-time quantitative PCR in 65 primary(More)
Autotaxin (ATX) is a 125-kD ectonucleotide pyrophosphate/phosphodiesterase, which was initially isolated and cloned from human melanoma cells as a potent stimulator of tumour cell motility. ATX shows 44% identity to the plasma cell membrane marker PC-1. Recently, we described the decreased expression of ATX mRNA in cultured fibroblast-like synoviocytes(More)
Roe deer are seasonal breeders and show cyclic variation in testicular volume and cellular differentiation within the tubular and interstitial testis compartment. We have employed the roe deer as a model to elucidate the expression of the postpubertal Leydig cell marker INSL3 during seasonal changes in Leydig cell differentiation. Roe deer testis and serum(More)
Aminopeptidase N (APN/CD13) is a transmembrane ectoenzyme occurring on a wide variety of cells. In contrast to monocytes and granulocytes, lymphocytes of peripheral blood do not express CD13 Ag. However, tumor-infiltrating T cells in renal cell cancer as well as synovial fluid T cells from patients suffering from various forms of arthritis can be CD13(More)
We characterized the immunophenotype as well as functional properties--phagocytosis, the uptake of acetylated LDL, and the expression of HLA class II antigens, adhesion molecules, and cytokine mRNA--of fibroblast-like synoviocytes from rheumatoid arthritis synovium. Skin fibroblasts (FB) and umbilical vein endothelial cells (HUVEC) were studied in parallel.(More)