|
|
Effect of endocrine disruptor bisphenol S on human health and reproduction
Procházková, Bára ; Petr, Jaroslav (advisor) ; Děd, Lukáš (referee)
Bisphenol S (BPS) is an environmental pollutant that has replaced bisphenol A (BPA) in plastic and paper products since 2011 as a safer "BPA-free" alternative. However, due to its rapid replacement, its potential adverse effects have not been investigated in detail, and due to its structural similarity to BPA, many studies suggest that it acts, like BPA, as an endocrine disruptor. Its use is wide and BPS is globally widespread, found in the environment and has been detected in both animal and human tissues. Nevertheless, an overall effect of BPS on an organism remains unclear. This work is focusing on gathering sources for its effect on reproductive ability and its association with metabolic disorders.
|
|
|
The Generation of Transgenic Huntington's Disease Miniature Pig
Baxa, Monika ; Motlík, Jan (advisor) ; Procházka, Jan (referee) ; Petr, Jaroslav (referee)
Huntingtons's disease (HD) is devastating neurodegenerative disorder manifesting by motor disturbances, cognitive decline and personal changes. The huge effort to find a cure for HD has brought several promising therapeutic treatments on the scene. Each of the prospective approaches needs to be investigated for safety, tolerability and efficacy. Mouse and rat models were a lot helpful in examination of pathological mechanisms of HD, but they are not sufficient for completion of pre-clinical testing. Therefore, we aimed to generate transgenic HD minipig to overcome the gap between rodents and humans. Minipig transgenic for the first 548 aminoacids of human mutant huntingtin gene (TgHD) under the control of human HD promotor was manipulated by lentiviral transduction of porcine one-cell stage embryos. Currently, six generations of minipigs expressing single copy of N-truncated human mutant huntingtin protein (mtHtt) with a repetition of 124 glutamines are at disposal. The more the model simulates the disease symptoms the better it is for translational research as the efficacy of the cure can be finer evaluated. Hence, the second aim was to demonstrate HD-like phenotype in our model. Testicular degeneration that preceded the clinical symptoms onset was observed as a consequence of expression of mtHtt....
|
|
|
Chemical communication of gametes
Otčenášková, Tereza ; Komrsková, Kateřina (advisor) ; Petr, Jaroslav (referee)
Fertilization is a multiple step process leading to fusion of female and male gametes resulting in a formation of a zygote. Besides direct gamete interaction via binding receptors localized on both oocyte and sperm surface, fertilization also involves communication based on chemical molecules triggering various signalling pathways. This work is aimed to characterize chemical communication of gametes of a model organism Mus musculus. For this purpose, modern proteomic and visualisation methods like nano-liquid chromatography tandem mass spectrometry (nLC-MS/MS), selected reaction monitoring (SRM) and immunofluorescent microscopy were used. Lipocalins were identified as candidate proteins involved in communication including those from major urinary proteins (MUPs), LCN lipocalins and fatty acid binding proteins (FABPs). For the first time, we report their presence in the sperm acrosome. Based on lipocalins capacity to bind and transport other molecules, we propose that these proteins have a protective and/or signalling role for gametes. Furthermore, chemical communication between sperm and oocyte is based on chemotaxis which enables their interaction before their fusion. In this work, we detected that spermatozoa show chemotactic responses in the presence of L-glutamate. This amino acid naturally...
|
|
|
Role and regulation of nuclear membrane during meiotic maturation of mammalian oocyte
Končická, Markéta ; Kubelka, Michal (advisor) ; Petr, Jaroslav (referee) ; Binarová, Pavla (referee)
Meiotic division of a female germ cell, an oocyte, is more prone to segregation errors and consequently to aneuploidies than meiosis of a sperm. Aneuploidies and chromosomal aberrations in oocytes increase with higher maternal age in humans and also in mice. Meiotic maturation onset is connected with activity of cyclin dependent kinase 1 (CDK1) that leads to dissociation of nuclear membrane. Moreover regulation of translation of key transcripts is necessary for proper meiotic progression. In thesis findings from four scientific publications are interpreted. We have analyzed the timing of nuclear envelope breakdown (NEBD) and polar body extrusion in mouse oocytes originating from two distinct female age groups: young (2 months old) and aged (12 months old). We found that meiotic maturation happens faster in aged females' oocytes due to early phosphorylation of Lamin A/C, a component of nuclear lamina, and rapid dissociation of nuclear membrane. Moreover aged females' oocytes presented unique characteristic invaginations of nuclear membrane and thus significantly increased circumference of the nuclear envelope compared to the oocytes from young females. These data combined with increased activity of CDK1 and Cyclin B, as well as increased translation of factors that regulate the translation itself,...
|
|
|
Creating a biosensor for miRNA effector complex formation using CRISPR nucleases
Petržílek, Jan ; Svoboda, Petr (advisor) ; Petr, Jaroslav (referee)
miRNAs are small regulatory RNAs, which function as post-transcriptional mRNA regulators. They direct ribonucleoprotein complexes to cognate mRNA to repress them by translational inhibition and degradation. miRNAs regulate thousands of mRNAs in mammals and have been recognized as regulatory factors in most cellular and developmental processes. Dysregulation of the miRNA pathway can lead to severe defects and diseases. Interestingly, a unique situation exists in mouse oocytes, where all the miRNA pathway components are present, yet the pathway is dispensable and nonfunctional, the molecular foundation of this phenomenon and its significance still remain unclear. In spite of the pronounced effects of the miRNA pathway in gene regulation in somatic cells, study strategies of the pathway bare limitations. Current methods for studying the activity of the miRNA pathway employ corelative studies (such as NGS) or reporter assays, which have relatively low throughput and are prone to artifacts. Here, I present design and development of a new strategy for directly monitor global miRNA pathway activity and integrity in near physiological conditions in living cells, which could also be employed in vivo for studies of mouse oocytes. The strategy is based on fluorescently tagged endogenous proteins of the...
|
|
| |
|
|
Phenotypic study Huntington's disease TgHD minipigs: Appearance and progress of reproductive and biochemical changes
Bohuslavová, Božena ; Motlík, Jan (advisor) ; Roth, Jan (referee) ; Petr, Jaroslav (referee) ; Krylov, Vladimír (referee)
Huntington's disease (HD) is one of the incurable and fatal diseases. HD belongs to the monogenic neurodegenerative diseases. According to the number of the CAG repetitions in the gene coding huntingtin, the onset of the disease is in childhood (5%), in the middle age, which is the most common (90%) and in the older age (5%). Beginning of the disease is manifested by changes in behavior; including problems with coordination and movement. Later, there is a psychological change. The disease leads to death. Until now, there is no effective curative treatment. In 2009, we created a model of the transgenic minipigs (TgHD) carrying the N - terminal part of the human mutant huntingtin (mtHtt) at our Institute in Liběchov. The number of offsprings and the resemblance in physiology and morphology between the pig (Sus scrofa) and humans (Homo sapiens) give us opportunities not only to study changes not only in central nerve organs, but also in peripheral tissues. The reproductive problems of TgHD boars were observed as the first phenotypic changes. Therefore, my work focuses at first on a study of the reproduction parameters of TgHD boars as well as ultrastructural, immunocytochemical and biochemical changes in testes and spermatozoa. In PhD thesis, I described in details the reproductive defects in TgHD...
|
|
| |
|
| |
|
|
Protein synthesis and protein degradation in mammalian oocyte development
Šušor, Andrej ; Motlík, Jan (advisor) ; Pěknicová, Jana (referee) ; Petr, Jaroslav (referee)
Concr,usroNs We anďysed eucaryoticinitiation t,anslation factorsthat are responsiblefor protein qmthesisin mammalianoocýes. As well we examinedthe affinity.of this factorsto.'mCap, Sepharoseduring in útro conďtion...Inour'laboratorywas optimisedthe protocol for generation of poreine parttrenotesthat serve us as a model for anďysis of. cellular processos in .rygotes with biochemical approaches.. : , , - Antibod}r micÍoanay analysis was used to investigate the: regulation of signalling pathways primarily during meiotic maturationof pig oocytesand subsequentlyin comparisonto other species(bovine,frog andseastar). on the base of proteomeanďysis of maturationof oocýes was chosenUCH-LI molebuleandis studiedin detail in mammalian oocyte. Abnost thorougily was analysed function of UCH-LI in porcine and bovine oocyte using specific inhibitors and overexpression. The mechanism that is involved UCH-LI in antipolyspermydefencein mammalian oocyte was unveiled in our laboratory.
|
guest ::
RSS feed.