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    Vascular Biology

     

    Vascular biology is a rapidly evolving field in medical research. During the past decades it became more and more evident that blood vessels are a very complex system, which is involved in the regulation of a variety of physiological and pathophysiological processes in the organism.

    The cellular substrate of Vascular Biology are cells of the vascular wall such as endothelial cells, smooth muscle cells, pericytes, and fibroblasts, as well as cells that interact with the vascular wall such as leukocytes or platelets, the products of megakaryocytes. Endothelial cells, leukocytes, and platelets participate in the regulation of blood coagulation, which prevents excessive blood loss after injury. However, if blood coagulation is disturbed, thrombus formation occurs.

    These thrombi may then lead to the occlusion of blood vessels, which results in malperfusion of the respective tissues and – depending on the localization – in events such as myocardial infarction or stroke. In addition, the process of clot dissolution or fibrinolysis is regulated by endothelial cells, but also by mast cells. Endothelial cells themselves also play a direct role in the regulation of tissue perfusion. They produce vasoactive mediators such as endothelins and NO, which act on vascular smooth muscle cells and thereby regulate the diameter of blood vessels.

    An important area within the field of vascular biology is the research on atherosclerosis, a major disease in Western countries with millions of affected patients in Europe and the United States. In atherosclerosis, initial inflammatory changes in the blood vessel lead to migration of monocytes/ macrophages into the vessel wall and to the development of “fatty streaks”. More and more macrophages invade the area and are transformed to so called foam cells, and smooth muscle cells proliferate. Inflammatory tissue edema, cellular proliferation, and matrix deposition increase the size of the lesion, which then protrudes into the vessel lumen and mechanically impedes blood flow. Such an atherosclerotic plaque can become instable with loss of vascular integrity and influx of plasma components into the vessel wall. The consequence can be plaque rupture with concomitant release of thrombogenic substances, which lead to the formation of a thrombus and to the complete occlusion of the blood vessel (see above). Finally, we should mention another area within the field of vascular biology: The formation of new blood vessels by sprouting from existing vessels (angiogenesis) or from stem cells (vasculogenesis), respectively. These processes play a central role in a variety of physiological and patho-(physio) logical processes. The formation of new blood vessels is essential for wound healing, reproduction, tumor growth and metastasis (to “survive” the tumor needs its own vessel supply).

    For these reasons it is evident that the study of vascular biology, from which only a few have been mentioned above, should allow the students to use their knowledge not only in basic research, but also in many clinical disciplines, such as cardiology, angiology, oncology, dermatology, and reproductive medicine. It is the aim of this program to educate scientists, who are able to independently perform basic as well as clinical research at the university level as well as outside the university. To reach this goal students enrolled in this program should be made familiar not only with basic principles of cell- and molecular biological aspects of vascular biology, but also with the application of this knowledge for the understanding of diseases and therapeutic concepts. This should be assured by the participation of both, basic research and clinical institutes, in this program