Wirkung des Lipidperoxidationsprodukts 4-Hydroxynonenal auf primäre Hepatocyten



    Oxidative stress plays a major role in pathophysiological (atherosclerosis, acute myocardial infarction, brain insult) and also in physiological (inflammation, immune response to microorganisms, traumatic stress and wound healing) processes.
    Hence, there are many experimental models of oxidative stress induction, but one of the most common models is ischemia/reperfusion injury.
    During ischemia there is accumulation of cytotoxic end-products of anaerobic metabolism. Reperfusion restores the blood flow, but does not only allow recovery of ischemic tissue; on the contrary, it causes severe damage by oxidative stress.
    Oxidative stress has been shown to play a regulatory role in liver regeneration eventually causing the migration of lymphocytes from spleen to liver. Splenic cells excrete cytokines that activate cytotoxic cells, which kill altered or damaged liver cells during regeneration, and thus are involved in the regulation of liver regeneration.

    a) In vitro studies:
    With respect to the proposed role of oxidative stress in the regulation of liver regeneration cytogenetic endpoints will further be analysed in cocultures of primary hepatocytes and splenic cells, and compared with the effects of pure hepatocyte cultures. Furthermore, both cytotoxic and potential growth modulating effects, as measured by the labeling and mitotic indices under the same experimental conditions, will be determined depending on different HNE concentrations. This should allow to define potential concentration effects - concentration dependence of the effects of HNE that will either trigger genotoxicity or modify cell proliferation. Proteins from the media of mixed cultures and from cell lysates will also be analyzed for HNE modifications with monoclonal antibodies against HNE-protein adducts. Protein analysis is expected to yield possible targets for HNE binding, which may play a role in cellular signaling.
    b) In vivo studies:
    Ischemia/reperfusion of the liver will be used as in vivo model for oxidative stress, and HNE formation will be monitored by immunohistochemical staining, with original monoclonal antibodies against HNE-protein adducts.
    Hepatocytes of such treated animals will additionally be cultured and analysed for potential cyto- and genotoxic effects. This experimental design should enable the determination of systemic influences on these endpoints which may not be detectable under the chosen in vitro conditions.

    The aim of this project is to analyse the effects of HNE-mediated oxidative stress in vitro on interactions between rat hepatocytes and spleen cells depending on ischemia-reperfusion injury of the liver as a model of oxidative stress induction in vivo.
    KurztitelWirkung von HNE auf primäre Hepatocyten
    Tatsächlicher Beginn/ -es Ende1/01/0631/12/07

    Systematik der Wissenschaftszweige 2002

    • 1407 Genetik