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Roles of acrosomal proteins in fertilization
Macíčková, Eliška ; Stopka, Pavel (advisor) ; Čermák, Lukáš (referee)
The acrosome is a crucial organelle for sperm cells. Defects in the biogenesis of the acrosome often lead to the impaired development of sperm cells and consequently, to the inability to fertilize the oocyte. Although it is evident that the acrosome is an essential structure, its main function has not been solved yet. The initial hypothesis was that the acrosome helps sperm to pass through the extracellular layers of the egg. This statement is based on evidence that acrosome is full of proteolytic enzymes, and inhibition of these enzymes reduces the ability to fertilize the oocyte. However, this hypothesis began to be questioned when it was found that (i) acrosome-reacted sperm cells are still able to pass through extracellular layers and fertilize the oocyte (ii) most of the sperm cells undergo premature acrosomal reaction before they reach the oocyte. Therefore, we aimed to characterize proteomes of the acrosome and acrosome- reacted sperm cells, identify important proteins using advanced bioinformatics approaches and discuss the function of the acrosome as a vesicle that serves to store and process metabolites after the previous maturation process. In this work, we revealed new findings that contribute to the hypothesis that acrosome is a lysosome-related organelle. Key words: sperm, acrosome,...
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The role of adrenergic signalling and mitochondria in cardioprotection
Macíčková, Eliška ; Žurmanová, Jitka (advisor) ; Holzerová, Kristýna (referee)
Cardiovascular diseases such as myocardial infarction or heart failure are one of the main causes of death in today's developed world. These diseases are accompanied by pathophysiological changes in the cell, which are very often associated with changes in adrenergic receptor signalling and mitochondrial function. Therefore, these functional units have been intensively studied in an attempt to discover the effective treatment. Currently, endogenous protective mechanisms are known to increase the resistance of heart to the pathophysiological states, and some of the mechanism targets directly into the mitochondria. In particular, the reduction in excessive production of reactive oxygen species and the decrease in sensitivity of mitochondrial permeability transition pore opening has been repeatedly described. Many of the contributing signalling pathways are related to adrenergic receptors. Thus, the aim of the present work is to link knowledge about the role of adrenergic signalling in cardioprotective mechanisms directed to mitochondria. Key words: heart, adrenergic signalization, mitochondria, cardioprotection
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