Thymotrophic effect of ether lipid 1-O-octadecyl-2-O-methoxy-rac-glicero-3-phosphocholine in the mouse

Non-invasive, quantitative assessment of the anatomical phenotype of corticotropin-releasing factor-overexpressing mice by MRI

High resolution magnetic resonance imaging (MRI) was applied to quantify alterations in thymus and adrenal volumes, as well as body fat in genetically engineered corticotropin-releasing factor (CRF)-overexpressing mice. When compared to the organs in age-matched wild-type animals, the adrenals in CRF-overexpressing male mice were significantly enlarged and the thymus volume in females was significantly smaller. The fat content was significantly larger in CRF-overexpressing mice. The anatomical alterations observed in the MRI studies were in perfect line with post-mortem data (weights of organs). Furthermore, the observed interstrain differences are in agreement with recently published data on (i) the effect of continuous, intraventricular infusion of CRF in rats and (ii) the presence of atrophic adrenals in CRF-knockout mice. The present studies demonstrate that MRI can provide reliable measures of relatively small structures such as the adrenal glands and the thymus in mice. This makes MRI an attractive, non-terminal tool to monitor in laboratory animals, including transgenic mice, the consequence of continuous stress on relevant organs.

ET-18-OCH(3)-induced cytotoxicity and DNA damage in rat astrocytes

The ether lipid 1-octadecyl-2-methyl-rac-glicero-3-phosphocholine (ET-18-OCH(3)) is known to be selectively cytotoxic toward several types of tumor cells, in which it seems to activate a process of apoptotic cell death. Moreover, the drug has been demonstrated to be active in normal cells too, particularly in rat astrocytes. In these cells at low dosage (from 1 to 6 microg/ml of medium) ET-18-OCH(3) stimulates maturation and protective responses, whereas at increasing dosages (from 8 to 20 microg/ml) it shows cytotoxic effects. The present study demonstrates that when ET-18-OCH(3) is added to astrocytes, it activates, in a time- and concentration-dependent manner, an oxidative process by increasing both the generation of reactive oxygen species (ROS), including nitric oxide, and lipid peroxidation. When there is a high ET-18-OCH(3) concentration or the time of treatment is prolonged, the increased oxidative condition seems to trigger DNA fragmentation (monitored by COMET assay) as well as loss in cell viability. These cytotoxic effects indicate that ROS may be considered, in our experimental model, as executioners of a program of cell death. In addition, ET-18-OCH(3) being a promising molecule in antitumor therapy, our data, while reinforcing the importance of monitoring the therapeutic drug dosage employed, also suggest that it may be useful to associate some antioxidants with antitumor treatments.