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The impact of post-translational modifications on TRPC5 ion channel activation and modulation
Mitro, Michal ; Zímová, Lucie (advisor) ; Dolejší, Eva (referee)
Transient Receptor Potential Canonical 5 (TRPC5), a calcium-permeable ion channel, acts as a versatile receptor in sensory neurons, kidneys, and the brain, impacting inflammatory responses and various types of pain. While post-translational modifications influence TRPC5 gating and membrane trafficking, only a few have been described so far. The identification of phosphorylation sites was based on available high-throughput bioinformatics and mass spectrometry data. Subsequently, functional characterization of these sites was conducted by introducing phospho-mimicking aspartate or phospho-null alanine mutations using site-directed mutagenesis. Utilizing patch-clamp in whole-cell configuration, membrane currents evoked by voltage or agonist stimuli were examined. The results revealed that individual substitutions at the N-terminal S193 and S195 with aspartates significantly slowed the gating kinetics. Additionally, a gain-of-function phenotype was observed with S193A. Molecular dynamics simulations provided insight into how phosphorylation at S193 induces changes in interactions among neighboring subunits. Moreover, biotinylation experiments indicated that the alterations in the activity of the S193 mutations are not due to increased targeting of the channels to the plasma membrane. Taken together,...
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The role of TRP ion channels in rheumatoid arthritis pain
Havrilčáková, Gabriela ; Zímová, Lucie (advisor) ; Heleš, Mário (referee)
Rheumatoid arthritis is a disease that affects many people across the world. It is a chronic autoimune disease causing inflammation in joints. The inflammation affects joint lining and causes gradual damage to the joint cartilage. Main symptoms are swelling and pain, The perception of pain is closely related to a group of TRP receptors expressed on sensory neurons. The state of inflammation in the affected joints also has a significant influence on the pain accopanying rheumatoid arthritis, in which participate the cells of the joint lining - synovial fibroblasts. They express a subset of TRP receptors that play a key role in the pathophysiology of arthritis development as well. In relation to pain and inflammation, the most studied TRP receptors are TRPV1 and TRPA1. This bachelor thesis describes the findings on these two receptors in relation to pain in rheumatoid arthritis. However, it also describes the TRPC5 receptor, whose inhibiton has only recently been shown in a mouse model to leads to exacerbation of symptoms. The results discussed in this bachelor's thesis show, that pharmacological modulation of the activity of TRP receptors is a promising way of possible future treatment of rheumatoid arthritis, including its main symptom - pain. Key words: rheumatoid arthritis, transient receptor...
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Incidence and Properties of Thermosensitive TRP Ion Channels in Cellular Models of Sensory Neurones
Loudová, Leona ; Vlachová, Viktorie (advisor) ; Boušová, Kristýna (referee)
Primary afferent sensory neurons enable all living organisms to survive in their environment and react to dangerous stimuli, including noxious and irritant chemicals, temperature, and pressure. These pseudo-unipolar neurons represent a heterologous population that, depending on functional properties, morphology, receptor equipment, degree of myelination, and conduction velocity, determines the intensity at which a stimulus is converted to an electrical signal that is then conducted to the central nervous system to elicit defensive response. The cell bodies of the peripheral sensory neurons are localized in the dorsal root ganglia (DRG) and cell lines derived from these neurons are intensively used not only to study the mechanisms of pain, but also to rationally search for substances with potential analgesic effect. The main goal of this bachelor's thesis is to summarize the current research on molecular mechanisms of nociception using cell lines derived from DRG neurons with a focus on a specific group of temperature-sensitive transient receptor potential (thermoTRP) ion channels. The aim is to present currently available studies focusing on cellular and molecular differences that result from different methodological approaches to the preparation and cultivation of cell cultures, especially in the...
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