Cardiac proteome analysis of a novel genetic mouse model of hypertension: the ET+/+eNOS-/-mice

• Antragsteller: Professor Dr. Franz Theuring
• Fachliche Zuordnung: Pharmakologie
• Förderung: Förderung von 2009 bis 2011
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 118394095

Endothelin-1 (ET) is a strong vasoconstrictive and mitogenic peptide mainly produced by the endothelial cells. It is functionally antagonized by nitric oxide (NO), a potent vasodilator and cardioprotective molecule, predominantly derived from endothelial NO-synthase (eNOS). The subtle balance between the endothelin and nitric oxide systems in controlling cardiovascular functions is from high clinical relevance. Despite the overexpression of a strong vasoconstrictor, the human ET transgenic mice (ET+/+ mice) remain normotensive. This lack of hypertension is believed to be the consequence of a compensatory effect of the nitric oxide system. In a way to disrupt this compensatory effect we decided to crossbreed ET+/+ mice and eNOS knock out (eNOS-/-) mice. The ET+/+eNOS-/- mice are hypertensive in comparison to wild type (WT), ET+/+ and even eNOS-/- mice. Nine months old ET+/+eNOS-/- are also characterized by endothelial dysfunction and cardiac fibrosis. Their ET receptor expression is modified. To understand the molecular causes of this phenotype we are studying the complete cardiac proteome of 3 months old male and female mice using high resolution Two Dimensional Gel Electrophoresis coupled to Mass Spectrometry (2DE/MS). The 2DE study brings to light the implication of some pathways in the process of hypertension and cardiac fibrosis in our model. Our first results obtained from male animals strongly suggest that some enzymes responsible for the regulation of oxidative stress (Peroxiredoxin and Superoxide Dismutase) are either differently expressed and/or that their post translationnal state, which regulates their function, is modified as results of the genetic modification. The finalization of the data sets for the female animals and the validation of the proteomic results by appropriate data bank searches and with conventional techniques like western blot, 2D Western Blot and immunohistochemistry is however of prime importance and therefore the main goal of the next months of our work. We apply therefore for a one year grant to conclude the work. These results already indicate that the proteome analysis plays an important role in the identification of new molecular pathways in the delicate interplay between these two vasoactive substances. By defining the underlying pathophysiological processes in more detail at this stage we then, in a next step, could interfere very precisely by targeting these particular molecular pathways pharmacologically to reverse hypertension and/or fibrosis in the ET+/+eNOS-/- mice.

• DFG-Verfahren: Sachbeihilfen