scholarly journals Caveolin-1 Facilitates the Direct Coupling between Large Conductance Ca2+-activated K+(BKCa) and Cav1.2 Ca2+Channels and Their Clustering to Regulate Membrane Excitability in Vascular Myocytes

2013 ◽  
Vol 288 (51) ◽  
pp. 36750-36761 ◽  
Author(s):  
Yoshiaki Suzuki ◽  
Hisao Yamamura ◽  
Susumu Ohya ◽  
Yuji Imaizumi
Keyword(s):  
Direct Coupling ◽  
Membrane Excitability ◽  
Caveolin 1 ◽  
Vascular Myocytes ◽  
Ca2 Channels

Neuroprotective Role of the B Vitamins in the Modulation of the Central Glutamatergic Neurotransmission

2021 ◽  
Vol 20 ◽  
Author(s):  
Shu-Kuei Huang ◽  
Cheng-Wei Lu ◽  
Tzu-Yu Lin ◽  
Su-Jane Wang
Keyword(s):  
Glutamate Release ◽  
B Vitamins ◽  
Nerve Terminals ◽  
Normal Brain ◽  
Membrane Excitability ◽  
Presynaptic Nerve Terminal ◽  
Normal Brain Function ◽  
Vesicular Exocytosis ◽  
Presynaptic Nerve Terminals ◽  
Ca2 Channels

Background: Regulation of glutamate release is crucial for maintaining normal brain function, but excess glutamate release is implicated in many neuropathological conditions. Therefore, the minimum glutamate release from presynaptic nerve terminals is an important neuroprotective mechanism. Objective: In this mini-review, we analyze the three B vitamins, namely vitamin B2 (riboflavin), vitamin B6 (pyridoxine), and vitamin B12 (cyanocobalamin), that affect the 4-aminopyridine (4-AP)-evoked glutamate release from presynaptic nerve terminal in rat and discuss their neuroprotective role. Methods: In this study, the measurements include glutamate release, DiSC3(5), and Fura-2. Results: The riboflavin, pyridoxine, and cyanocobalamin produced significant inhibitory effects on 4-aminopyridine-evoked glutamate release from rat cerebrocortical nerve terminals (synaptosomes) in a dose-dependent relationship. These presynaptic inhibitory actions of glutamate release are attributed to inhibition of physiologic Ca2+-dependent vesicular exocytosis but not Ca2+-independent nonvesicular release. These effects also did not affect membrane excitability, while diminished cytosolic [Ca2+]c through a reduction of direct Ca2+ influx via Cav2.2 (N-type) and Cav2.1 (P/Q-type) Ca2+ channels, rather than through indirect Ca2+ induced Ca2+ release from ryanodine-sensitive intracellular stores. Furthermore, their effects were attenuated by GF109203X and Ro318220, two protein kinase C (PKC) inhibitors, suggesting suppression of PKC activity. Taken together, these results suggest that riboflavin, pyridoxine, and cyanocobalamin inhibit presynaptic vesicular glutamate release from rat cerebrocortical synaptosomes, through the depression Ca2+ influx via voltage-dependent Cav2.2 (N-type) and Cav2.1 (P/Q-type) Ca2+ channels, and PKC signaling cascade. Conclusion: Therefore, these B vitamins may reduce the strength of glutamatergic synaptic transmission and is of considerable importance as potential targets for therapeutic agents in glutamate-induced excitation-related diseases.

scholarly journals Arachidonic acid inhibition of L-type calcium (CaV1.3b) channels varies with accessory CaVβ subunits

2009 ◽  
Vol 133 (4) ◽  
pp. 387-403 ◽  
Author(s):  
Mandy L. Roberts-Crowley ◽  
Ann R. Rittenhouse
Keyword(s):  
Arachidonic Acid ◽  
Enzyme Activation ◽  
Membrane Excitability ◽  
Recovery From Inactivation ◽  
293 Cells ◽  
Dependent Inactivation ◽  
Accessory Subunits ◽  
Kinetics Of ◽  
Ca2 Channels

Arachidonic acid (AA) inhibits the activity of several different voltage-gated Ca2+ channels by an unknown mechanism at an unknown site. The Ca2+ channel pore-forming subunit (CaVα1) is a candidate for the site of AA inhibition because T-type Ca2+ channels, which do not require accessory subunits for expression, are inhibited by AA. Here, we report the unanticipated role of accessory CaVβ subunits on the inhibition of CaV1.3b L-type (L-) current by AA. Whole cell Ba2+ currents were measured from recombinant channels expressed in human embryonic kidney 293 cells at a test potential of −10 mV from a holding potential of −90 mV. A one-minute exposure to 10 µM AA inhibited currents with β1b, β3, or β4 58, 51, or 44%, respectively, but with β2a only 31%. At a more depolarized holding potential of −60 mV, currents were inhibited to a lesser degree. These data are best explained by a simple model where AA stabilizes CaV1.3b in a deep closed-channel conformation, resulting in current inhibition. Consistent with this hypothesis, inhibition by AA occurred in the absence of test pulses, indicating that channels do not need to open to become inhibited. AA had no effect on the voltage dependence of holding potential–dependent inactivation or on recovery from inactivation regardless of CaVβ subunit. Unexpectedly, kinetic analysis revealed evidence for two populations of L-channels that exhibit willing and reluctant gating previously described for CaV2 channels. AA preferentially inhibited reluctant gating channels, revealing the accelerated kinetics of willing channels. Additionally, we discovered that the palmitoyl groups of β2a interfere with inhibition by AA. Our novel findings that the CaVβ subunit alters kinetic changes and magnitude of inhibition by AA suggest that CaVβ expression may regulate how AA modulates Ca2+-dependent processes that rely on L-channels, such as gene expression, enzyme activation, secretion, and membrane excitability.

scholarly journals Alterations in Caveolin-1 Expression and Receptor-Operated Ca2+ Entry in the Aortas of Rats with Pulmonary Hypertension

2016 ◽  
Vol 39 (2) ◽  
pp. 438-452 ◽  
Author(s):  
Yun-Ping Mu ◽  
Da-Cen Lin ◽  
Fu-Rong Yan ◽  
Hai-Xia Jiao ◽  
Long-Xin Gui ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Smooth Muscle ◽  
Cardiovascular Diseases ◽  
Smooth Muscle Cells ◽  
Transient Receptor Potential ◽  
Muscle Cells ◽  
Pathological Process ◽  
Functional Changes ◽  
Caveolin 1 ◽  
Ca2 Channels

Background/Aims: Alterations in intracellular Ca2+ concentration ([Ca2+]i) underlie the pathogenesis of various cardiovascular diseases. Caveolin-1 (Cav-1) is the primary functional protein associated with caveolae, which are invaginations in the plasma membrane, and is a regulator of [Ca2+]i signaling. Caveolae and Cav-1 increase the activity of store-operated Ca2+ channels (SOCC) in rat pulmonary arterial smooth muscle cells (PASMCs), and these enhancing effects were more pronounced in rats with pulmonary hypertension (PH). Classical transient receptor potential (TRPC) proteins are highly expressed in vascular smooth muscle cells, and these proteins form functional receptor-operated Ca2+ channels (ROCC) and SOCC in PASMCs. Previous studies suggested that functional and structural changes in aortas might occur during the pathological process of PH. Our data demonstrated that Cav-1 and TRPC were also abundant in the aorta smooth muscle cells (AoSMCs) of PH rats. However, previous PH research primarily focused on Ca2+ channels in pulmonary arteries, but not functional changes in Ca2+ channels in aortas. The contribution of Cav-1 of AoSMCs to alterations of Ca2+ signaling in aortic functions during the pathological process of PH has not been fully characterized. Therefore, this study investigated alterations in Cav-1 expression and the relationship of these changes to Ca2+ channels in AoSMCs of PH rats. Methods: The present study examined physiological caveolae and Cav-1 expression and characterized the function of altered Cav-1 expression in rat aortas with PH. Results: The appearance of caveolae with Cav-1 expression increased significantly in the aortas of rats with PH, but TRPC1 and TRPC6 expression was not altered. In vitro experiments demonstrated that caveolae contributed to phenylephrine, endothelin-1, and 1-oleoyl-2-acetyl-sn-glycerol (OAG)-induced aortic vasoreactivity, but KCl and cyclopiazonic acid had no effect, which suggests the vital ability of Cav-1 to regulate ROCC activity. The introduction of Cav-1 scaffolding domain peptide enhanced OAG-induced ROCC function in primary AoSMCs. Conclusion: Cav-1 is specifically associated with ROCC in aortas and plays a vital role in altering vasoreactivity, which affects cardiovascular diseases pathology. Caveolae and Cav-1 up-regulation may affect the function of ROCC in rat models of PH.

1422: Oxytocin Receptor and Caveolin-1 Expression in the Prostate of Young and Aging Male

2005 ◽  
Vol 173 (4S) ◽  
pp. 385-386
Author(s):  
Gregor Bötticher ◽  
Zsófia Herbert ◽  
Erdogan Sendemir ◽  
Andreas Aschoff ◽  
Gustav Friedrich Jirikowski ◽  
...  
Keyword(s):  
Oxytocin Receptor ◽  
Aging Male ◽  
Caveolin 1

Modulation der TGF-β abhängigen CTGF Induktion durch Caveolin-1 in Hepatozyten

2009 ◽  
Vol 47 (09) ◽  
Author(s):  
C Meyer ◽  
C Stump ◽  
A Müller ◽  
S Dooley
Keyword(s):  
Caveolin 1

Single Cell Based Microelectrode Array Biosensors

2003 ◽  
Vol 773 ◽  
Author(s):  
Mo Yang ◽  
Shalini Prasad ◽  
Xuan Zhang ◽  
Mihrimah Ozkan ◽  
Cengiz S. Ozkan
Keyword(s):  
Electrical Activity ◽  
Single Cell ◽  
Cellular Response ◽  
Microelectrode Array ◽  
Fast Fourier Transformation ◽  
Chemical Agent ◽  
Extracellular Potential ◽  
Membrane Excitability ◽  
Specific Chemical ◽  
Chemical Agents

AbstractExtracellular potential is an important parameter which indicates the electrical activity of live cells. Membrane excitability in osteoblasts plays a key role in modulating the electrical activity in the presence of chemical agents. The complexity of cell signal makes interpretation of the cellular response to a chemical agent very difficult. By analyzing shifts in the signal power spectrum, it is possible to determine a frequency spectrum also known as Signature Pattern Vectors (SPV) specific to a chemical. It is also essential to characterize single cell sensitivity and response time for specific chemical agents for developing detect-to-warn biosensors. We used a 4x4 multiple Pt microelectrode array to spatially position single osteoblast cells, by using a gradient AC field. Fast Fourier Transformation (FFT) and Wavelet Transformation (WT) analyses were used to extract information pertaining to the frequency of firing from the extracellular potential.

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