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Calcium signalling in astrocytes under physiological and pathological conditions
Svatoňová, Petra ; Anděrová, Miroslava (advisor) ; Kolář, David (referee)
Calcium signalling in astrocytes represents an important component, which enables proper neuronal functioning under physiological conditions. Alterations in Ca2+ signalling, accompanied by an increase in intracellular calcium levels is a hallmark for numerous pathological states of central nervous system, such as traumatic and ischemic brain/spinal cord injuries, epilepsy as well as neurodegenerative diseases, such as Alzheimer's disease and psychiatric disorders, such as schizophrenia. The research analyzing the molecular components of astrocytic Ca2+ signalling can help us understand the control mechanisms used in calcium signalling and thus be greatly beneficial for further therapeutic research. Powered by TCPDF (www.tcpdf.org)
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Ca2+ signalling in magnocellular neurones of the rat supraoptic nucleus.
Kortus, Štěpán ; Zápotocký, Martin (advisor) ; Šuta, Daniel (referee) ; Hromádka, Tomáš (referee)
The magnocellular neurosecretory cells (MNCs) of the hypothalamus project axons from the supraoptic nucleus to the posterior pituitary gland, where they secrete either oxytocin or vasopressin into the circulation. Oxytocin is important for delivery at birth and is essential for milk ejection during suckling. Vasopressin primarily promotes water reabsorption in the kidney to maintain body fluid balance. The profile of oxytocin and vasopressin secretion is principally determined by the pattern of action potentials initiated at the cell bodies in the hypothalamus. MNCs principally secrete hormones from terminals in the pituitary, but the secretion also occurs from their dendrites in the supraoptic nucleus, where they diffuse and affect the neighbouring cells. Mechanisms controlling the oxytocin and vasopressin secretion from MNCs have been extensively studied over the last decades and it is assumed that the relationship between Ca2+ signalling, secretion from dendrites, and the firing patterns is essential in understanding the magnocellular neurosecretory system. In this project, we combine mathematical analysis and experimental measurements of Ca2+ activity of MNCs of transgenic rats expressing an arginine vasopressin-enhanced green fluorescent protein (AVP-eGFP) or oxytocin-monomeric red fluorescent...
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Ca2+ signalling in magnocellular neurones of the rat supraoptic nucleus.
Kortus, Štěpán ; Zápotocký, Martin (advisor) ; Šuta, Daniel (referee) ; Hromádka, Tomáš (referee)
The magnocellular neurosecretory cells (MNCs) of the hypothalamus project axons from the supraoptic nucleus to the posterior pituitary gland, where they secrete either oxytocin or vasopressin into the circulation. Oxytocin is important for delivery at birth and is essential for milk ejection during suckling. Vasopressin primarily promotes water reabsorption in the kidney to maintain body fluid balance. The profile of oxytocin and vasopressin secretion is principally determined by the pattern of action potentials initiated at the cell bodies in the hypothalamus. MNCs principally secrete hormones from terminals in the pituitary, but the secretion also occurs from their dendrites in the supraoptic nucleus, where they diffuse and affect the neighbouring cells. Mechanisms controlling the oxytocin and vasopressin secretion from MNCs have been extensively studied over the last decades and it is assumed that the relationship between Ca2+ signalling, secretion from dendrites, and the firing patterns is essential in understanding the magnocellular neurosecretory system. In this project, we combine mathematical analysis and experimental measurements of Ca2+ activity of MNCs of transgenic rats expressing an arginine vasopressin-enhanced green fluorescent protein (AVP-eGFP) or oxytocin-monomeric red fluorescent...
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Calcium signalling in astrocytes under physiological and pathological conditions
Svatoňová, Petra ; Anděrová, Miroslava (advisor) ; Kolář, David (referee)
Calcium signalling in astrocytes represents an important component, which enables proper neuronal functioning under physiological conditions. Alterations in Ca2+ signalling, accompanied by an increase in intracellular calcium levels is a hallmark for numerous pathological states of central nervous system, such as traumatic and ischemic brain/spinal cord injuries, epilepsy as well as neurodegenerative diseases, such as Alzheimer's disease and psychiatric disorders, such as schizophrenia. The research analyzing the molecular components of astrocytic Ca2+ signalling can help us understand the control mechanisms used in calcium signalling and thus be greatly beneficial for further therapeutic research. Powered by TCPDF (www.tcpdf.org)
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Fluorescence studies of bacterial membrane proteins and cell signalling.
Fišer, Radovan ; Konopásek, Ivo (advisor) ; Hof, Martin (referee) ; Forstová, Jitka (referee)
(English) This work is based on five publications studying mostly adenylate cyclase toxin (CyaA) from Bordetella pertussis and its interaction with biological membranes. CyaA permeabilizes cell membranes by forming small cationselective pores and subverts cellular signaling by delivering an adenylate cyclase (AC) enzyme that converts ATP to cAMP into host cells. First study clarifies the membrane disruption mechanisms of CyaA and another bacterial RTX toxin; αhemolysin (HlyA) from Escherichia coli. For this purpose, we employed a fluorescence requenching method using liposomes as target membranes. We showed that both toxins induced a graded leakage of liposome content with different ion selectivities (Fišer a Konopásek 2009). Both AC delivery and pore formation were previously shown to involve a predicted amphipathic αhelix(502522). In the second publication we investigated another predicted transmembrane αhelix(565591) that comprises a Glu(570) and Glu(581) pair. We examined the roles of these glutamates in the activity of CyaA, mostly on planar lipid membranes end erythrocytes. Negative charge at position 570, but not at position 581, was found to be essential for cation selectivity of the pore, suggesting a role of Glu(570) in...
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