Dataset Information

Blockade of the forward Na+ /Ca2+ exchanger suppresses the growth of glioblastoma cells through Ca2+ -mediated cell death.

ABSTRACT: BACKGROUND AND PURPOSE:The Na+ /Ca2+ exchanger (NCX) working in either forward or reverse mode participates in maintaining intracellular Ca2+ ([Ca2+ ]i ) homeostasis, which is essential for determining cell fate. Previously, numerous blockers targeting reverse or forward NCX have been developed and studied in ischaemic tissue injury but barely examined in glioblastoma for the purpose of anti-tumour therapy. We assessed the effect of NCX blockers on glioblastoma growth and whether NCX can become a therapeutic target. EXPERIMENTAL APPROACH:Patch-clamp recording, Ca2+ imaging, flow cytometry, and Western blot were used to study the effects of specific and non-specific NCX blockers on cultured glioblastoma cells. In vivo bioluminescent imaging was used to measure effects on grafted glioblastoma. KEY RESULTS:Selectively blocking the reverse NCX with SEA0400, SN-6, and YM-244769 did not affect tumour cell viability. Blocking the forward NCX with bepridil, CB-DMB, or KB-R7943 elevated [Ca2+ ]i and killed glioblastoma cells. Bepridil and CB-DMB caused Ca2+ -dependent cell cycle arrest together with apoptosis, which were all attenuated by a Ca2+ chelator BAPTA-AM. Systemic administration of bepridil inhibited growth of brain-grafted glioblastoma. Bepridil did not appear to have a cytotoxic effect on human astrocytes, which have higher functional expression of NCX than glioblastoma cells. CONCLUSIONS AND IMPLICATIONS:Low expression of the NCX makes glioblastoma cells sensitive to disturbance of [Ca2+ ]i . Interventions designed to block the forward NCX can cause Ca2+ -mediated injury to glioblastoma thus having therapeutic potential. Bepridil could be a lead compound for developing new anti-tumour drugs.

SUBMITTER: Hu HJ

PROVIDER: S-EPMC6609550 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Blockade of the forward Na+ /Ca2+ exchanger suppresses the growth of glioblastoma cells through Ca2+ -mediated cell death.

Hu Hui-Jie HJ Wang Shan-Shan SS Wang Yan-Xia YX Liu Yan Y Feng Xue-Mei XM Shen Ying Y Zhu Liang L Chen Hong-Zhuan HZ Song Mingke M

British journal of pharmacology 20190617 15

<h4>Background and purpose</h4>The Na+ /Ca2+ exchanger (NCX) working in either forward or reverse mode participates in maintaining intracellular Ca2+ ([Ca2+ ]i ) homeostasis, which is essential for determining cell fate. Previously, numerous blockers targeting reverse or forward NCX have been developed and studied in ischaemic tissue injury but barely examined in glioblastoma for the purpose of anti-tumour therapy. We assessed the effect of ...[more]

PMID: 31034096

Similar Datasets

Project description:Inherited retinal degenerations (IRDs) are a group of untreatable and commonly blinding diseases characterized by progressive photoreceptor loss. IRD pathology has been linked to an excessive activation of cyclic nucleotide-gated channels (CNGC) leading to Na+- and Ca2+-influx, subsequent activation of voltage-gated Ca2+-channels (VGCC), and further Ca2+ influx. However, a connection between excessive Ca2+ influx and photoreceptor loss has yet to be proven.Here, we used whole-retina and single-cell RNA-sequencing to compare gene expression between the rd1 mouse model for IRD and wild-type (wt) mice. Differentially expressed genes indicated links to several Ca2+-signalling related pathways. To explore these, rd1 and wt organotypic retinal explant cultures were treated with the intracellular Ca2+-chelator BAPTA-AM or inhibitors of different Ca2+-permeable channels, including CNGC, L-type VGCC, T-type VGCC, Ca2+-release-activated channel (CRAC), and Na+/Ca2+ exchanger (NCX). Moreover, we employed the novel compound NA-184 to selectively inhibit the Ca2+-dependent protease calpain-2. Effects on the retinal activity of poly(ADP-ribose) polymerase (PARP), sirtuin-type histone-deacetylase, calpains, as well as on activation of calpain-1, and - 2 were monitored, cell death was assessed via the TUNEL assay.While rd1 photoreceptor cell death was reduced by BAPTA-AM, Ca2+-channel blockers had divergent effects: While inhibition of T-type VGCC and NCX promoted survival, blocking CNGCs and CRACs did not. The treatment-related activity patterns of calpains and PARPs corresponded to the extent of cell death. Remarkably, sirtuin activity and calpain-1 activation were linked to photoreceptor protection, while calpain-2 activity was related to degeneration. In support of this finding, the calpain-2 inhibitor NA-184 protected rd1 photoreceptors.These results suggest that Ca2+ overload in rd1 photoreceptors may be triggered by T-type VGCCs and NCX. High Ca2+-levels likely suppress protective activity of calpain-1 and promote retinal degeneration via activation of calpain-2. Overall, our study details the complexity of Ca2+-signalling in photoreceptors and emphasizes the importance of targeting degenerative processes specifically to achieve a therapeutic benefit for IRDs. Video Abstract.

Project description:Introduction: Safranal, which endows saffron its unique aroma, causes vasodilatation and has a hypotensive effect in animal studies, but the mechanisms of these effects are unknown. In this study, we investigated the mechanisms of safranal vasodilation. Methods: Isolated rat endothelium-intact or -denuded aortic rings were precontracted with phenylephrine and then relaxed with safranal. To further assess the involvement of nitric oxide, prostaglandins, guanylate cyclase, and phospholipase A2 in safranal-induced vasodilation, aortic rings were preincubated with L-NAME, indomethacin, methylene blue, or quinacrine, respectively, then precontracted with phenylephrine, and safranal concentration-response curves were established. To explore the effects of safranal on Ca2+ influx, phenylephrine and CaCl2 concentration-response curves were established in the presence of safranal. Furthermore, the effect of safranal on aortic rings in the presence of ouabain, a Na+-K+ ATPase inhibitor, was studied to explore the contribution of Na+/Ca2+ exchanger to this vasodilation. Results: Safranal caused vasodilation in endothelium-intact and endothelium-denuded aortic rings. The vasodilation was not eliminated by pretreatment with L-NAME, indomethacin, methylene blue, or quinacrine, indicating the lack of a role for NO/cGMP. Safranal significantly inhibited the maximum contractions induced by phenylephrine, or by CaCl2 in Ca2+-free depolarizing buffer. Safranal also relaxed contractions induced by ouabain, but pretreatment with safranal totally abolished the development of ouabain contractions. Discussion/Conclusion: Inhibition of Na+-K+ ATPase by ouabain leads to the accumulation of Na+ intracellularly, forcing the Na+/Ca2+ exchanger to work in reverse mode, thus causing a contraction. Inhibition of the development of this contraction by preincubation with safranal indicates that safranal inhibited the Na+/Ca2+ exchanger. We conclude that safranal vasodilation is mediated by the inhibition of calcium influx from extracellular space through L-type Ca2+ channels and by the inhibition of the Na+/Ca2+ exchanger.

Project description:BackgroundWhile calcium is known to play a crucial role in mammalian sperm physiology, how it flows in and out of the male gamete is not completely understood. Herein, we investigated the involvement of Na+/Ca2+ exchangers (NCX) in mammalian sperm capacitation. Using the pig as an animal model, we first confirmed the presence of NCX1 and NCX2 isoforms in the sperm midpiece. Next, we partially or totally blocked Ca2+ outflux (forward transport) via NCX1/NCX2 with different concentrations of SEA0400 (2-[4-[(2,5-difluorophenyl)methoxy]phenoxy]-5-ethoxyaniline; 0, 0.5, 5 and 50 µM) and Ca2+ influx (reverse transport) with SN6 (ethyl 2-[[4-[(4-nitrophenyl)methoxy]phenyl]methyl]-1,3-thiazolidine-4-carboxylate; 0, 0.3, 3 or 30 µM). Sperm were incubated under capacitating conditions for 180 min; after 120 min, progesterone was added to induce the acrosome reaction. At 0, 60, 120, 130, and 180 min, sperm motility, membrane lipid disorder, acrosome integrity, mitochondrial membrane potential (MMP), tyrosine phosphorylation of sperm proteins, and intracellular levels of Ca2+, reactive oxygen species (ROS) and superoxides were evaluated.ResultsPartial and complete blockage of Ca2+ outflux and influx via NCX induced a significant reduction of sperm motility after progesterone addition. Early alterations on sperm kinematics were also observed, the effects being more obvious in totally blocked than in partially blocked samples. Decreased sperm motility and kinematics were related to both defective tyrosine phosphorylation and mitochondrial activity, the latter being associated to diminished MMP and ROS levels. As NCX blockage did not affect the lipid disorder of plasma membrane, the impaired acrosome integrity could result from reduced tyrosine phosphorylation.ConclusionsInhibition of outflux and influx of Ca2+ triggered similar effects, thus indicating that both forward and reverse Ca2+ transport through NCX exchangers are essential for sperm capacitation.

Dataset Information

Blockade of the forward Na+ /Ca2+ exchanger suppresses the growth of glioblastoma cells through Ca2+ -mediated cell death.

Publications

Blockade of the forward Na<sup>+</sup> /Ca<sup>2+</sup> exchanger suppresses the growth of glioblastoma cells through Ca<sup>2+</sup> -mediated cell death.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets