Understanding the role of rudhira in cell migration

Abstract

This thesis describes the functional analysis of the cytoskeletal protein Rudhira in cell migration. Rudhira is predominantly expressed in the embryonic vasculature and adult neo-angiogenic processes such as wound healing and pathological processes such as tumor progression. Rudhira is a cytoskeletal protein that plays a key role in directional cell migration, by facilitating actin cytoskeleton reorganization and focal adhesion turnover. Several in vivo and in vitro model systems such as the fruit fly, mouse, zebrafish and endothelial cell lines are used for characterization of the fine-tuned and complex regulatory networks that regulate blood vessel formation. Two such model systems that are used in our laboratory to study the functions of Rudhira are rudhira knockout mice and rudhira knockdown endothelial cell lines. I have generated a rudhira knockout endothelial cell line, which could serve as a resource and also overcome some of the limitations of the previous models. The inherent difference in the predicted domain architecture of the two halves of Rudhira suggests differences in their molecular functions primarily with respect to cell migration. Thus, using techniques like in vitro wound healing assay and immunostaining, I have attributed some of the cell migration steps regulated by Rudhira, including, microtubule stabilization and stress fiber reduction, to the two halves of the protein. Taken together, this study offers fresh insights into the mechanism of regulation of cell migration by Rudhira and may be applicable to better understanding the role of cell migration in blood vessel formation. Development of the cardiovascular system requires the formation of blood vessels, which occurs by two main processes: vasculogenesis and angiogenesis. Blood vessel formation occurs during embryogenesis as well as in adults, both in physiological conditions like wound healing and menstrual cycle and pathological conditions such as ischemia, retinopathies and tumors. Dysregulation of such a critical process is often associated with vascular diseases or metastatic tumors. The cellular and molecular mechanisms of physiological and pathological angiogenesis are quite similar. Hence, molecules which are expressed in both contexts are of great significance since they would not only provide a better understanding of vascular development, but may prove to be potential therapeutic targets.