|
|
Role of oxidative stress in male infertility.
Dolečková, Barbora ; Tlapáková, Tereza (advisor) ; Šanovec, Ondřej (referee)
Oxidative stress is a phenomenon caused by an excess of reactive oxygen species (ROS), or by insufficient activity of antioxidants, that reduces these ROS levels and thereby protect the organism from oxidative damage. ROS have two types of origin: endogenous, which includes leukocytes and immature sperm, and exogenous, which includes factors such as air pollution caused by heavy metals, smoking tobacco products, obesity and others. Low levels of ROS have a positive effect on the physiological functions of the organism, including the process of spermatogenesis, where ROS participates in the course of hyperactivation and capacitation. However, increased levels of ROS trigger a number of cellular pathologies, whether the loss of fluidity of biological membranes due to lipid peroxidation, deformation of enzymatic proteins or DNA fragmentation, which negatively affects individuals' infertility. Due to the significant positive correlation of ROS scavenging by antioxidants with improving sperm parameters of an infertile individual, antioxidant therapy has recently begun to be used as a possible successful component of male idiopathic infertility treatment.
|
|
|
LINC complex: The link between chromatin integrity and sperm motility
Šanovec, Ondřej ; Komrsková, Kateřina (advisor) ; Lánská, Eva (referee)
The LINC complex (Linker of the Nucleoskeleton and Cytoskeleton) is a protein structure located in the nuclear membrane that connects the cytoskeleton with the nucleoskeleton. This complex can be found in every mammalian cell including the gametes. However, here the LINC complex is more diverse and less studied than in the somatic cells. In this thesis, the LINC complex and its role in spermiogenesis have been studied in wild-type and Protamine 2 knockout (Prm2-/- ) mice. Protamines are small proteins that replace histones during spermiogenesis. The mouse model generated by the group of prof. Hubert Schorle has a deletion in Prm2 in exon 1 and its sperm possess a surprising phenotype including complete loss of motility. Therefore, it was hypothesized that the LINC complex might be responsible for miscommunication between the sperm head and tail which leads to the loss of sperm motility. Results from this study suggest that the LINC complex is not influenced by Prm2 deletion, however, actin dynamics, cytoskeletal motor proteins and tubulin acetylase/ histone deacetylase activity might be impaired. Prm2-/- sperm have a significantly higher abundance of β-actin compared to the wild type. Next, Prm2-/- sperm also show a different pattern of acetylation of α-tubulin but no change in the abundance of...
|
guest ::
