Can 4-chloro-m-cresol be substituted for caffeine as an activator of calcium oscillation in bullfrog sympathetic ganglion cells?

Higure, Yoko; Shimazaki, Yoshihiro; Nohmi, Mitsuo

doi:10.1016/j.ceca.2006.01.007

Cited by 3 publications

(3 citation statements)

References 14 publications

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“…We used two different RyR agonists, caffeine (10 mM) and 4-cmc (1 mM) 31 , to trigger currents recorded in whole cell mode from acutely isolated mouse ventricular cardiomyocytes voltage-clamped at a holding potential of -70 mV. Recordings were done in extracellular normal-Tyrode and intracellular KAsp based solutions (see Materials and methods).…”

Section: Ryr Agonists Trigger Unitary Current Activity With Properties That Resemble Cx43 Hc Openingmentioning

confidence: 99%

RyR2 regulates Cx43 hemichannel intracellular Ca2+-dependent activation in cardiomyocytes

Lissoni

Hulpiau

Martins‐Marques

et al. 2019

Cardiovascular Research

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Aims Connexin-based gap junctions are crucial for electrical communication in the heart; they are each composed of two docked hemichannels (HCs), supplied as unpaired channels via the sarcolemma. When open, an unpaired HC forms a large pore, high-conductance and Ca2+-permeable membrane shunt pathway that may disturb cardiomyocyte function. HCs composed of connexin 43 (Cx43), a major cardiac connexin, can be opened by electrical stimulation but only by very positive membrane potentials. Here, we investigated the activation of Cx43 HCs in murine ventricular cardiomyocytes voltage-clamped at −70 mV. Methods and results Using whole-cell patch-clamp, co-immunoprecipitation, western blot analysis, immunocytochemistry, proximity ligation assays, and protein docking studies, we found that stimulation of ryanodine receptors (RyRs) triggered unitary currents with a single-channel conductance of ∼220 pS, which were strongly reduced by Cx43 knockdown. Recordings under Ca2+-clamp conditions showed that both RyR activation and intracellular Ca2+ elevation were necessary for HC opening. Proximity ligation studies indicated close Cx43-RyR2 apposition (<40 nm), and both proteins co-immunoprecipitated indicating physical interaction. Molecular modelling suggested a strongly conserved RyR-mimicking peptide sequence (RyRHCIp), which inhibited RyR/Ca2+ HC activation but not voltage-triggered activation. The peptide also slowed down action potential repolarization. Interestingly, alterations in the concerned RyR sequence are known to be associated with primary familial hypertrophic cardiomyopathy. Conclusion Our results demonstrate that Cx43 HCs are intimately linked to RyRs, allowing them to open at negative diastolic membrane potential in response to RyR activation.

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Section: Ryr Agonists Trigger Unitary Current Activity With Properties That Resemble Cx43 Hc Openingmentioning

confidence: 99%

RyR2 regulates Cx43 hemichannel intracellular Ca2+-dependent activation in cardiomyocytes

Lissoni

Hulpiau

Martins‐Marques

et al. 2019

Cardiovascular Research

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“…Interestingly, upon re‐introduction of external Ca 2+ into the bath solution, caffeine induced the release of Ca 2+ followed by a significant SOCE, but 4‐CEP only induced a robust release of Ca 2+ with little Ca 2+ influx (Zeng et al ., ). Furthermore, caffeine evokes intracellular Ca 2+ oscillations in bullfrog sympathetic ganglion cells, but the 4‐CEP analogue cresol does not (Higure et al ., ). These observations strongly suggest the existence of functional coupling between RyRs and SOCs via intracellular STIM1 movement, and that caffeine and 4‐CEP probably have different effects on the dynamics of intracellular Ca 2+ .…”

Section: Introductionmentioning

confidence: 97%

The ryanodine receptor agonist 4‐chloro‐3‐ethylphenol blocks ORAI store‐operated channels

Zeng

Chen

Daskoulidou

et al. 2014

British J Pharmacology

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BACKGROUNDDepletion of the Ca 2+ store by ryanodine receptor (RyR) agonists induces store-operated Ca 2+ entry (SOCE). 4-Chloro-3-ethylphenol (4-CEP) and 4-chloro-m-cresol (4-CmC) are RyR agonists commonly used as research tools and diagnostic reagents for malignant hyperthermia. Here, we investigated the effects of 4-CEP and its analogues on SOCE. EXPERIMENTAL APPROACHSOCE and ORAI1-3 currents were recorded by Ca 2+ imaging and whole-cell patch recordings in rat L6 myoblasts and in HEK293 cells overexpressing STIM1/ORAI1-3. KEY RESULTS4-CEP induced a significant release of Ca 2+ in rat L6 myoblasts, but inhibited SOCE. The inhibitory effect was concentration-dependent and more potent than its analogues 4-CmC and 4-chlorophenol (4-ClP). In the HEK293 T-REx cells overexpressing STIM1/ORAI1-3, 4-CEP inhibited the ORAI1, ORAI2 and ORAI3 currents evoked by thapsigargin. The 2-APB-induced ORAI3 current was also blocked by 4-CEP. This inhibitory effect was reversible and independent of the Ca 2+ release. The two analogues, 4-CmC and 4-ClP, also inhibited the ORAI1-3 channels. Excised patch and intracellular application of 4-CEP demonstrated that the action site was located extracellularly. Moreover, 4-CEP evoked STIM1 translocation and subplasmalemmal clustering through its Ca 2+ store-depleting effect via the activation of RyR, but no effect on STIM1 redistribution was observed in cells co-expressing STIM1/ORAI1-3. CONCLUSION AND IMPLICATIONS4-CEP not only acts as a RyR agonist to deplete the Ca 2+ store and trigger STIM1 subplasmalemmal translocation and clustering, but also directly inhibits ORAI1-3 channels. These findings demonstrate a novel pharmacological property for the chlorophenol derivatives that act as RyR agonists. Abbreviations

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“…The human recombinant form of insulin (Humulin‐R) additionally includes the expedient 4‐cloro‐ m ‐cresol (Lilly). Cresol has been shown to have effects in cell physiology, such as the activation of ryanodine receptor‐mediated calcium release from calcium stores (Treves et al ., 2002), including in neurons (Higure et al ., 2006). It was therefore relevant to test if the observed effects on K + currents were artefactually determined by cresol.…”

Section: Resultsmentioning

confidence: 99%

Insulin increases excitability via a dose‐dependent dual inhibition of voltage‐activated K⁺ currents in differentiated N1E‐115 neuroblastoma cells

Lima

Vicente

Alves

et al. 2008

Eur J of Neuroscience

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A role in the control of excitability has been attributed to insulin via modulation of potassium (K(+)) currents. To investigate insulin modulatory effects on voltage-activated potassium currents in a neuronal cell line with origin in the sympathetic system, we performed whole-cell voltage-clamp recordings in differentiated N1E-115 neuroblastoma cells. Two main voltage-activated K(+) currents were identified: (a) a relatively fast inactivating current (I(fast) - time constant 50-300 ms); (b) a slow delayed rectifying K(+) current (I(slow) - time constant 1-4 s). The kinetics of inactivation of I(fast), rather than I(slow), showed clear voltage dependence. I(fast) and I(slow) exhibited different activation and inactivation dependence for voltage, and have different but nevertheless high sensitivities to tetraethylammonium, 4-aminopyridine and quinidine. In differentiated cells - rather than in non-differentiated cells - application of up to 300 nm insulin reduced I(slow) only (IC(50) = 6.7 nm), whereas at higher concentrations I(fast) was also affected (IC(50) = 7.7 microm). The insulin inhibitory effect is not due to a change in the activation or inactivation current-voltage profiles, and the time-dependent inactivation is also not altered; this is not likely to be a result of activation of the insulin-growth-factor-1 (IGF1) receptors, as application of IGF1 did not result in significant current alteration. Results suggest that the current sensitive to low concentrations of insulin is mediated by erg-like channels. Similar observations concerning the insulin inhibitory effect on slow voltage-activated K(+) currents were also made in isolated rat hippocampal pyramidal neurons, suggesting a widespread neuromodulator role of insulin on K(+) channels.

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Can 4-chloro-m-cresol be substituted for caffeine as an activator of calcium oscillation in bullfrog sympathetic ganglion cells?

Cited by 3 publications

References 14 publications

RyR2 regulates Cx43 hemichannel intracellular Ca2+-dependent activation in cardiomyocytes

RyR2 regulates Cx43 hemichannel intracellular Ca2+-dependent activation in cardiomyocytes

The ryanodine receptor agonist 4‐chloro‐3‐ethylphenol blocks ORAI store‐operated channels

Insulin increases excitability via a dose‐dependent dual inhibition of voltage‐activated K⁺ currents in differentiated N1E‐115 neuroblastoma cells

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Can 4-chloro-m-cresol be substituted for caffeine as an activator of calcium oscillation in bullfrog sympathetic ganglion cells?

Cited by 3 publications

References 14 publications

RyR2 regulates Cx43 hemichannel intracellular Ca2+-dependent activation in cardiomyocytes

RyR2 regulates Cx43 hemichannel intracellular Ca2+-dependent activation in cardiomyocytes

The ryanodine receptor agonist 4‐chloro‐3‐ethylphenol blocks ORAI store‐operated channels

Insulin increases excitability via a dose‐dependent dual inhibition of voltage‐activated K+ currents in differentiated N1E‐115 neuroblastoma cells

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Insulin increases excitability via a dose‐dependent dual inhibition of voltage‐activated K⁺ currents in differentiated N1E‐115 neuroblastoma cells