Estrogenicity of alkylphenols and alkylated non-phenolics in a rainbow trout (Oncorhynchus mykiss) primary hepatocyte culture.

Alkylphenols act as estrogen mimics by binding to and transactivating estrogen receptors (ERs) in fish. In the present study, activation of ER-mediated production of the estrogenic biomarker vitellogenin (vtg) in a primary culture of rainbow trout (Oncorhynchus mykiss) hepatocytes was used to construct a structure-activity relationship for this ubiquitous group of aquatic pollutants. The role of alkyl chain length and branching, substituent position, number of alkylated groups, and the requirement of a phenolic ring structure was assessed.

Cytotoxicity of alkylphenols and alkylated non-phenolics in a primary culture of rainbow trout (Onchorhynchus mykiss) hepatocytes.

Alkylphenols are common aquatic pollutants originating from industrial use of the compounds themselves or as biodegradation products of alkylphenol polyethoxylates. The cytotoxicity of a range of alkylphenols and alkylated non-phenolics were assessed in a primary culture of rainbow trout (Onchorhynchus mykiss) hepatocytes to construct a structure-toxicity relationship for this group of ubiquitous aquatic pollutants. Metabolic inhibition and loss of membrane integrity were used as cytotoxic endpoints through use of the cellular markers Alamar blue and 5-carboxyfluorescein diacetate acetoxymethyl ester, respectively.

Effluents from oil production activities contain chemicals that interfere with normal function of intra- and extra-cellular estrogen binding proteins.

Some environmental pollutants have the ability to alter the endocrine function in fish through interaction with the estrogen receptor (ER). Many of these chemicals are also able to interfere with the endocrine system through other mechanisms of action, however. The plasma sex steroid-binding protein (SBP), which is involved in regulating circulating levels of endogenous sex steroids, has recently been proposed to contribute to pollutant induced disruption of endocrine homeostasis.

Use of fish in vitro hepatocyte assays to detect multi-endpoint toxicity in Slovenian river sediments.

There is an increasing demand for rapid, sensitive and robust methods for toxicity testing of single chemicals, complex mixtures and environmental samples. The objective of this work was to validate and use a primary culture of rainbow trout (Oncorhynchus mykiss) hepatocytes as a multi-endpoint in vitro bioassay for toxicity characterisation of river sediments from four areas of the Sava and Krupa Rivers (Slovenia). The endpoints were chosen to encompass acute toxicity (cytotoxicity) as well as sub-lethal biomarker and effect endpoints such as metabolic inhibition, DNA damage (Fast Micromethod), endocrine disruption (estrogenicity), and 7-ethoxyresorufin O-deethylase (EROD) activity.

Characterization of a novel Eph receptor tyrosine kinase, EphA10, expressed in testis.

In mammals, 14 members of the Eph receptor tyrosine kinase family have been described so far. Here we present a not yet described member of this family denoted EphA10. We report the identification of three putative EphA10 isoforms: one soluble and two transmembrane isoforms.

Ephrin-A1 binding to CD4+ T lymphocytes stimulates migration and induces tyrosine phosphorylation of PYK2.

Eph receptors, the largest subfamily of receptor tyrosine kinases, and their ephrin ligands are important mediators of cell-cell communication regulating cell attachment, shape, and mobility. Here we demonstrate that CD4+ T lymphocytes express the EphA1 and EphA4 receptors and that these cells bind the ligand ephrin-A1. Further we show ephrin-A1 expression in vivo on high endothelial venule (HEV) endothelial cells.

Identification of a novel centrosome/microtubule-associated coiled-coil protein involved in cell-cycle progression and spindle organization.

Here we describe the identification of a novel vertebrate-specific centrosome/spindle pole-associated protein (CSPP) involved in cell-cycle regulation. The protein is predicted to have a tripartite domain structure, where the N- and C-terminal domains are linked through a coiled-coil mid-domain. Experimental analysis of the identified domains revealed that spindle association is dependent on the N-terminal and the coiled-coil mid domain.

Expression and functional effects of Eph receptor tyrosine kinase A family members on Langerhans like dendritic cells.

Background: The Eph receptors are the largest receptor tyrosine kinase family. Several family members are expressed in hematopoietic cells. Previously, the expression of a member of this family, EphA2, was identified on dendritic like cells in tonsils.