The family of stromal interaction molecules (STIM) includes two widely expressed single-pass endoplasmic reticulum (ER) transmembrane proteins and additional splice variants that act as precise ER-luminal Ca2+ sensors. STIM proteins mainly function as one of the two essential components of the so-called Ca2+ release-activated Ca2+ (CRAC) channel. The second CRAC channel component is constituted by pore-forming Orai proteins in the plasma membrane. STIM and Orai physically interact with each other to enable CRAC channel opening, which is a critical prerequisite for various downstream signalling pathways such as gene transcription or proliferation. Their activation commonly requires the emptying of the intracellular ER Ca2+ store. Using their Ca2+ sensing capabilities, STIM proteins confer this Ca2+ content-dependent signal to Orai, thereby linking Ca2+ store depletion to CRAC channel opening. Here we review the conformational dynamics occurring along the entire STIM protein upon store depletion, involving the transition from the quiescent, compactly folded structure into an active, extended state, modulation by a variety of accessory components in the cell as well as the impairment of individual steps of the STIM activation cascade associated with disease.
- Klíčová slova
- CRAC, EF‐hand, STIM1, STIM1 C‐terminus,
- MeSH
- kanály aktivované uvolněním vápníku * MeSH
- membránové proteiny metabolismus MeSH
- protein ORAI1 MeSH
- protein STIM1 metabolismus MeSH
- proteiny STIM * metabolismus MeSH
- vápník metabolismus MeSH
- vápníková signalizace fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- kanály aktivované uvolněním vápníku * MeSH
- membránové proteiny MeSH
- protein ORAI1 MeSH
- protein STIM1 MeSH
- proteiny STIM * MeSH
- vápník MeSH
Calcium influx through plasma membrane calcium release-activated calcium (CRAC) channels, which are formed of hexamers of Orai1, is a potent trigger for many important biological processes, most notably in T cell-mediated immunity. Through a bioinformatics-led cell biological screen, we have identified Orai1 as a substrate for the rhomboid intramembrane protease RHBDL2. We show that RHBDL2 prevents stochastic calcium signaling in unstimulated cells through conformational surveillance and cleavage of inappropriately activated Orai1. A conserved disease-linked proline residue is responsible for RHBDL2's recognizing the active conformation of Orai1, which is required to sharpen switch-like signaling triggered by store-operated calcium entry. Loss of RHBDL2 control of CRAC channel activity causes severe dysregulation of downstream CRAC channel effectors, including transcription factor activation, inflammatory cytokine expression, and T cell activation. We propose that this surveillance function may represent an ancient activity of rhomboid proteases in degrading unwanted signaling proteins.
- Klíčová slova
- CRAC channel, Orai1, RHBDL2, T cell, calcium, rhomboid protease, signalling, transmembrane,
- MeSH
- aktivace lymfocytů MeSH
- buněčná membrána metabolismus MeSH
- Drosophila melanogaster MeSH
- gating iontového kanálu MeSH
- HEK293 buňky MeSH
- konformace proteinů MeSH
- lidé MeSH
- membránové proteiny metabolismus MeSH
- mutace MeSH
- proteasy chemie MeSH
- protein ORAI1 chemie MeSH
- serinové endopeptidasy metabolismus MeSH
- signální transdukce MeSH
- stochastické procesy MeSH
- vápník metabolismus MeSH
- vápníková signalizace fyziologie MeSH
- vápníkové kanály chemie MeSH
- vazba proteinů MeSH
- výpočetní biologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- membránové proteiny MeSH
- ORAI1 protein, human MeSH Prohlížeč
- Orai1 protein, mouse MeSH Prohlížeč
- proteasy MeSH
- protein ORAI1 MeSH
- RHBDL2 protein, human MeSH Prohlížeč
- RHBDL2 protein, mouse MeSH Prohlížeč
- serinové endopeptidasy MeSH
- vápník MeSH
- vápníkové kanály MeSH
The fertilization of freshwater fish occurs in an environment that may negatively affect the gametes; therefore, the specific mechanisms triggering the encounters of gametes would be highly expedient. The egg and ovarian fluid are likely the major sources of these triggers, which we confirmed here for rainbow trout (Oncorhynchus mykiss). The ovarian fluid affected significantly spermatozoa performance: it supported high velocity for a longer period and changed the motility pattern from tumbling in water to straightforward moving in the ovarian fluid. Rainbow trout ovarian fluid induced a trapping chemotaxis-like effect on activated male gametes, and this effect depended on the properties of the activating medium. The interaction of the spermatozoa with the attracting agents was accompanied by the "turn-and-run" behavior involving asymmetric flagellar beating and Ca2+ concentration bursts in the bent flagellum segment, which are characteristic of the chemotactic response. Ovarian fluid created the optimal environment for rainbow trout spermatozoa performance, and the individual peculiarities of the egg (ovarian fluid)-sperm interaction reflect the specific features of the spawning process in this species.
- Klíčová slova
- Oncorhynchus mykiss, chemotaxis, fertilization, ovarian fluid, sperm motility,
- MeSH
- chemotaxe fyziologie MeSH
- fertilizace fyziologie MeSH
- Oncorhynchus mykiss metabolismus MeSH
- ovarium cytologie metabolismus MeSH
- spermie cytologie metabolismus MeSH
- vápníková signalizace fyziologie MeSH
- zvířata MeSH
- zygota cytologie metabolismus MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Neuronal voltage-gated calcium channels play a pivotal role in the conversion of electrical signals into calcium entry into nerve endings that is required for the release of neurotransmitters. They are under the control of a number of cellular signaling pathways that serve to fine tune synaptic activities, including G-protein coupled receptors (GPCRs) and the opioid system. Besides modulating channel activity via activation of second messengers, GPCRs also physically associate with calcium channels to regulate their function and expression at the plasma membrane. In this mini review, we discuss the mechanisms by which calcium channels are regulated by classical opioid and nociceptin receptors. We highlight the importance of this regulation in the control of neuronal functions and their implication in the development of disease conditions. Finally, we present recent literature concerning the use of novel μ-opioid receptor/nociceptin receptor modulators and discuss their use as potential drug candidates for the treatment of pain.
- Klíčová slova
- G-protein coupled receptors, Mu opioid receptor, Nociception opioid receptor, Voltage-gated calcium channels,
- MeSH
- agonisté vápníkových kanálů farmakologie MeSH
- blokátory kalciových kanálů farmakologie MeSH
- lidé MeSH
- neurony účinky léků fyziologie MeSH
- opioidní analgetika farmakologie MeSH
- receptory opiátové agonisté fyziologie MeSH
- vápníková signalizace účinky léků fyziologie MeSH
- vápníkové kanály fyziologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- agonisté vápníkových kanálů MeSH
- blokátory kalciových kanálů MeSH
- opioidní analgetika MeSH
- receptory opiátové MeSH
- vápníkové kanály MeSH
The aim of this study was to evaluate cell diversity by considering how Ca(2+) signaling has been adapted in skeletal muscle cell function. We characterized single C2C12 myoblasts through intracellular Ca(2+) signaling kinetics after exposure to specific drugs and calcium blockers using fast fluorescence microspectrofluorimetry followed by ATP effect analysis, which confirmed the expression of functional purinergic adenosine and P2 receptors. Further, we found that glutamate sensitivity of C2C12 cells was mediated by ionotropic glutamate receptors; on the other hand, most cells were responsive to cyclopiazonic acid, which inhibits the sarco-endoplasmic reticulum Ca(2+)-ATPase pump. These results suggest that C2C12 cells possess functional L- and P/Q-type voltage-operated Ca(2+) channels, ryanodine receptors and functional sarcoplasmic reticulumCa(2+) stores (typical for muscle cells), adenosine and P2 purinergic receptors, as well as ionotropic glutamate receptors. The evaluation of intracellular Ca(2+) signaling is a promising approach towards a better understanding and control of the physiopathological properties of myogenic cells that could be used as a predictive factor in the selection of optimal cells for scaffold recellularization or for tissue engineered constructs used in stem cell therapy.
The extracellular matrix (ECM) consists of proteins, glycosaminoglycans and glycoproteins, that support the dynamic interactions between cells, including intercellular communication, cell attachment, cell differentiation, cell growth and migration. As such, the ECM represents an essential and very sensitive system within the tissue microenvironment that is involved in processes such as tissue regeneration and carcinogenesis. The aim of the present review is to evaluate its diversity through Ca(2+) signaling and its role in muscle cell function. Here, we discuss some methodological approaches dissecting Ca(2+) handling mechanisms in myogenic and non-myogenic cells, e.g. the importance of Ca(2+) and calpains in muscle dystrophy. We also consider the reconstruction of skeletal muscle by colonization of decellularized ECM with muscle-derived cells isolated from skeletal muscle. Therefore, it is necessary to establish new methodological procedures based on Ca(2+) signaling in skeletal muscle cells and their effect on ECM homeostasis, allowing the monitoring of skeletal muscle reconstruction and organ repair.
Calcium ions act like ubiquitous second messengers in a wide amount of cellular processes. In cardiac myocytes, Ca2+ handling regulates the mechanical contraction necessary to the heart pump function. The field of intracellular and intercellular Ca2+ handling, employing in vitro models of cardiomyocytes, has become a cornerstone to understand the role and adaptation of calcium signalling in healthy and diseased hearts. Comprehensive in vitro systems and cell-based biosensors are powerful tools to enrich and speed up cardiac phenotypic and drug response evaluation. We have implemented a combined setup to measure contractility and calcium waves in human embryonic stem cells-derived cardiomyocyte 3D clusters, obtained from embryoid body differentiation. A combination of atomic force microscopy to monitor cardiac contractility, and sensitive fast scientific complementary metal-oxide-semiconductor camera for epifluorescence video recording, provided correlated signals in real time. To speed up the integrated data processing, we tested several post-processing algorithms, to improve the automatic detection of relevant functional parameters. The validation of our proposed method was assessed by caffeine stimulation (10mM) and detection/characterization of the induced cardiac response. We successfully report the first simultaneous recording of cardiac contractility and calcium waves on the described cardiac 3D models. The drug stimulation confirmed the automatic detection capabilities of the used algorithms, measuring expected physiological response, such as elongation of contraction time and Ca2+ cytosolic persistence, increased calcium basal fluorescence, and transient peaks. These results contribute to the implementation of novel, integrated, high-information, and reliable experimental systems for cardiac models and drug evaluation.
- Klíčová slova
- atomic force microscopy, biosignals filtering, caffeine, calcium imaging, cardiac differentiation, embryoid bodies, fluorescence microscopy, human stem cell-derived cardiomyocytes,
- MeSH
- biofyzika metody MeSH
- kardiomyocyty metabolismus MeSH
- lidé MeSH
- vápník metabolismus MeSH
- vápníková signalizace fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- vápník MeSH
Pioglitazone (PIO) is a thiazolidindione antidiabetic agent which improves insulin sensitivity and reduces blood glucose in experimental animals and treated patients. At the cellular level the actions of PIO in diabetic heart are poorly understood. A previous study has demonstrated shortened action potential duration and inhibition of a variety of transmembrane currents including L-type Ca(2+) current in normal canine ventricular myocytes. The effects of PIO on shortening and calcium transport in ventricular myocytes from the Goto-Kakizaki (GK) type 2 diabetic rat have been investigated. 10 min exposure to PIO (0.1-10 microM) reduced the amplitude of shortening to similar extents in ventricular myocytes from GK and control rats. 1 microM PIO reduced the amplitude of the Ca(2+) transients to similar extents in ventricular myocytes from GK and control rats. Caffeine-induced Ca(2+) release from the sarcoplasmic reticulum and recovery of Ca(2+) transients following application of caffeine and myofilament sensitivity to Ca(2+) were not significantly altered in ventricular myocytes from GK and control rats. Amplitude of L-type Ca(2+) current was not significantly decreased in myocytes from GK compared to control rats and by PIO treatment. The negative inotropic effects of PIO may be attributed to a reduction in the amplitude of the Ca(2+) transient however, the mechanisms remain to be resolved.
- MeSH
- biologický transport účinky léků MeSH
- diabetes mellitus 2. typu farmakoterapie patofyziologie MeSH
- experimentální diabetes mellitus farmakoterapie patofyziologie MeSH
- hypoglykemika farmakologie terapeutické užití MeSH
- kardiomyocyty účinky léků fyziologie MeSH
- kontrakce myokardu účinky léků fyziologie MeSH
- krysa rodu Rattus MeSH
- pioglitazon MeSH
- potkani Wistar MeSH
- srdeční komory účinky léků MeSH
- thiazolidindiony farmakologie terapeutické užití MeSH
- vápníková signalizace účinky léků fyziologie MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- hypoglykemika MeSH
- pioglitazon MeSH
- thiazolidindiony MeSH
In ischemic/reperfusion (I/R) injured hearts, severe oxidative stress occurs and is associated with intracellular calcium (Ca(2+)) overload. Glucagon-Like Peptide-1 (GLP-1) analogues have been shown to exert cardioprotection in I/R heart. However, there is little information regarding the effects of GLP-1 analogue on the intracellular Ca(2+) regulation in the presence of oxidative stress. Therefore, we investigated the effects of GLP-1 analogue, (liraglutide, 10 microM) applied before or after hydrogen peroxide (H(2)O(2), 50 microM) treatment on intracellular Ca(2+) regulation in isolated cardiomyocytes. We hypothesized that liraglutide can attenuate intracellular Ca(2+) overload in cardiomyocytes under H(2)O(2)-induced cardiomyocyte injury. Cardiomyocytes were isolated from the hearts of male Wistar rats. Isolated cardiomyocytes were loaded with Fura-2/AM and fluorescence intensity was recorded. Intracellular Ca(2+) transient decay rate, intracellular Ca(2+) transient amplitude and intracellular diastolic Ca(2+) levels were recorded before and after treatment with liraglutide. In H(2)O(2) induced severe oxidative stressed cardiomyocytes (which mimic cardiac I/R) injury, liraglutide given prior to or after H(2)O(2) administration effectively increased both intracellular Ca(2+) transient amplitude and intracellular Ca(2+) transient decay rate, without altering the intracellular diastolic Ca(2+) level. Liraglutide attenuated intracellular Ca(2+) overload in H(2)O(2)-induced cardiomyocyte injury and may be responsible for cardioprotection during cardiac I/R injury by preserving physiological levels of calcium handling during the systolic and diastolic phases of myocyte activation.
- MeSH
- hypoglykemika farmakologie MeSH
- intracelulární tekutina účinky léků metabolismus MeSH
- kardiomyocyty účinky léků metabolismus MeSH
- krysa rodu Rattus MeSH
- kultivované buňky MeSH
- liraglutid farmakologie MeSH
- oxidační stres účinky léků fyziologie MeSH
- peroxid vodíku toxicita MeSH
- potkani Wistar MeSH
- vápníková signalizace účinky léků fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- hypoglykemika MeSH
- liraglutid MeSH
- peroxid vodíku MeSH
Moringa oleifera is a plant whose fruits, roots and leaves have been advocated for traditional medicinal uses. The physicochemical analysis shows that Moringa oleifera contains more dietary polyunsaturated fatty acids (PUFA) than saturated fatty acids (SFA). The consumption of an experimental diet enriched with Moringa oleifera extracts lowered blood pressure in spontaneously hypertensive rats (SHR), but not in normotensive Wistar-Kyoto (WKY) rats as compared to rats fed an unsupplemented control diet. Anti-CD3-stimulated T cell proliferation was diminished in both strains of rats fed the Moringa oleifera. The experimental diet lowered secretion of interleukin-2 in SHR, but not in WKY rats compared with rats fed the control diet. Studies of platelets from patients with primary hypertension and from SHR support the notion that the concentration of intracellular free calcium [Ca(2+)](i) is modified in both clinical and experimental hypertension. We observed that the basal, [Ca(2+)](i) was lower in T cells of SHR than in those of WKY rats fed the control diet. Feeding the diet with Moringa oleifera extracts to WKY rats did not alter basal [Ca(2+)](i) in T cells but increased basal [Ca(2+)](i) in SHR. Our study clearly demonstrated that Moringa oleifera exerts antihypertensive effects by inhibiting the secretion of IL-2 and modulates T cell calcium signaling in hypertensive rats.
- MeSH
- antihypertenziva izolace a purifikace farmakologie terapeutické užití MeSH
- hypertenze farmakoterapie imunologie patofyziologie MeSH
- krysa rodu Rattus MeSH
- listy rostlin MeSH
- Moringa oleifera * MeSH
- potkani inbrední SHR MeSH
- potkani inbrední WKY MeSH
- rostlinné extrakty izolace a purifikace farmakologie terapeutické užití MeSH
- T-lymfocyty účinky léků fyziologie MeSH
- tělesná hmotnost účinky léků fyziologie MeSH
- vápníková signalizace účinky léků fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antihypertenziva MeSH
- rostlinné extrakty MeSH
